FUNGICIDAL ACTION AS AFFECTED BY INTERACTION OF NICKEL CHLORIDE, NABAM, ZINEB, AND ZINC SULPHATE

1961 ◽  
Vol 39 (3) ◽  
pp. 519-530 ◽  
Author(s):  
F. R. Forsyth ◽  
C. H. Unwin
Keyword(s):  
Zinc Sulphate ◽  
Early Blight ◽  
Fungicidal Activity ◽  
Test Organism ◽  
Brown Rot ◽  
Nickel Chloride ◽  
Fungicidal Action ◽  
Chloride Hexahydrate ◽  
Wettable Powder ◽  
Test Organisms

Protectant fungicidal action of mixtures of nabam, zineb, nickel chloride, and zinc sulphate was evaluated by means of a "microbeaker method" and the slide germination method, using as test organisms the fungi causing leaf rust of wheat, crown rust of oats, early blight of tomatoes, and brown rot of peaches. All of the fungicides tested were more effective against the two rusts than against the organisms causing early blight and brown rot. The relatively insoluble nickel ethylenebisdithiocarbamate was much less effective than the other chemicals tested. Ratios (w/w) of nickel chloride hexahydrate to zineb around unity and to nabam plus zinc sulphate from 2–10 to 1 showed an unfavorable effect on fungitoxic activity against urediospores of P. recondita. The ratio showing greatest antagonism varied, depending on the test organism used and whether or not tankmix or wettable powder zineb was used. The formation of nickel ethylenebisdithiocarbamate in the aqueous solution and its low fungicidal activity adequately explain the results obtained.

Bioaerosol Exposure Method for Package Integrity Testing†

1996 ◽  
Vol 59 (7) ◽  
pp. 768-771 ◽  
Author(s):  
SCOTT W. KELLER ◽  
JOSEPH E. MARCY ◽  
BARBARA A. BLAKISTONE ◽  
GEORGE H. LACY ◽  
CAMERON R. HACKNEY ◽  
...  
Keyword(s):  
Particle Size ◽  
Test Organism ◽  
Hole Diameter ◽  
Pseudomonas Fragi ◽  
Integrity Testing ◽  
Aerosol Exposure ◽  
Exposure Method ◽  
Test Organisms ◽  
Organism Growth ◽  
Bioaerosol Exposure

Test organism motility, concentration, aerosol exposure time, hole diameter and length were evaluated to determine their influence on microbial ingress into a flexible plastic pouch. Microtubes with 10- and 20-μm hole diameters and of 5- and 10-mm lengths were used as defects in 128 flexible pouches. A bioaerosol with a 2.68-μm mean particle size comprised of 102 or 106 CFU/ml source concentrations of motile or nonmotile Pseudomonas fragi TM 849 was introduced into a 119,911-cm3 chamber for exposures of 15 or 30 minutes. Six pouches showed test organism growth after a 72-h incubation period. Microbial ingress was significant (P < .05) for motile test organisms with source concentrations of 106 CFU/ml.

scholarly journals Evaluation of the Larvicidal Potential of the Leaf Extracts of Hyptis suaveolens Poit against Anopheles Mosquitoes

2018 ◽  
pp. 1-9
Author(s):  
Amaka, John I. ◽  
Attah, D. Daniel ◽  
Obisike, Victor U. ◽  
Benedict, Aboje G.
Keyword(s):  
Mosquito Control ◽  
Larval Instar ◽  
Test Organism ◽  
Phytochemical Screening ◽  
Leaf Extracts ◽  
Anopheles Mosquitoes ◽  
Lc50 Value ◽  
Hyptis Suaveolens ◽  
Test Organisms ◽  
Layer Chromatography

This study evaluated the larvicidal potential of the ethanolic and aqueous leaf extracts of Hyptis suaveolens Poit on the 4th larval instar of laboratory-reared Anopheles spp at varying concentrations of 0.1ml, 0.2ml, 0.3ml, 0.4ml and 0.5ml for specified periods of 24hrs, 48hrs and 72hrs. Qualitative phytochemical screening of the leaf extracts identified bioactive components like alkaloid, saponin, phenol, anthraquinone and flavonoid. The LC50 and LC90 values obtained indicate that the ethanolic leaf extracts of Hyptis suaveolens Poit had the greatest toxicity on the test organisms within 24hrs of exposure at median LC50 value of 0.485ml compared to the LC50 value of 0.625ml by its aqueous extract. The relative median potency estimates indicate that within 24 hrs, the ethanolic Hyptis suaveolens Poit was 0.161 times more potent on the test organism than aqueous Hyptis suaveolens Poit. The result of this research, therefore, underscores the efficacy of Hyptis suaveolens Poit as an eco-friendly alternative in Anopheles mosquito control. It is, therefore, recommended that quantitative phytochemical screening, application of column chromatography as well as thin layer chromatography be carried out on the extracts to isolate and purify toxic phytochemicals with larvicidal potentiality.

Single- and multi-species toxicity testing with nematodes.

2021 ◽  
pp. 298-322
Author(s):  
Sebastian Höss
Keyword(s):  
Caenorhabditis Elegans ◽  
Test Organism ◽  
Toxicity Testing ◽  
Single Species ◽  
Risk Assessments ◽  
Freshwater Sediments ◽  
Nematode Communities ◽  
Model Ecosystems ◽  
Test Organisms ◽  
Experimental Approaches

Abstract This chapter discusses the utility of nematodes in experimental ecotoxicology, and specifically in the study of freshwaters. Drawing on reports in which nematodes were used as test organisms in single-species tests as well as studies investigating nematode communities in model ecosystems (i.e. microcosms), the suitability of nematode-based experimental approaches in prospective and retrospective risk assessments of chemicals in freshwater sediments is examined. Several examples are presented of the use of Caenorhabditis elegans as a test organism in single-species bioassays, in order to demonstrate the versatility of this nematode for ecotoxicological investigations.

Some Principles of Microbiological Turbidimetric Assays of Antibiotics

1979 ◽  
Vol 62 (4) ◽  
pp. 951-956
Author(s):  
Robert A Rippere
Keyword(s):  
Linear Response ◽  
Test Organism ◽  
Limited Range ◽  
Liquid Media ◽  
Agar Diffusion ◽  
Assay Procedure ◽  
Test Organisms ◽  
Effective Use

Abstract Turbidimetric methods for determining the potency of antibiotics are inherently more accurate and more precise than are comparable agar diffusion procedures, but assays conducted in liquid media are subject to degradation from less than ideal conditions to a much greater extent than are diffusion methods. The relationships between test organisms, antibiotics, and assay concentrations are discussed. A valid assay procedure must produce a linear response with an adequate slope (–0.4 to –1.2) by the test organism to increasing concentrations of drug; such linear response normally occurs over a limited range of concentrations. Criteria used to select photometers that offer the greatest advantages to analytical microbiologists are described, with guidelines for the most effective use of the chosen instrument.

Synthesis of nickel hydroxychloride microspheres via a facile template-free process and their conversion to β-Ni(OH)2 microspheres

CrystEngComm ◽  
2014 ◽  
Vol 16 (48) ◽  
pp. 11050-11057 ◽  
Author(s):  
Kay He ◽  
Gaoling Zhao ◽  
Gaorong Han
Keyword(s):  
Nickel Chloride ◽  
Hydrolysis Reaction ◽  
Solvothermal Process ◽  
Nickel Chloride Hexahydrate ◽  
Free Process ◽  
Chloride Hexahydrate ◽  
Forced Hydrolysis ◽  
Template Free ◽  
Forced Hydrolysis Reaction

Hierarchical flower-like nickel hydroxychloride microspheres were prepared by forced hydrolysis reaction of nickel chloride hexahydrate in ethanol via a facile template-free solvothermal process.

scholarly journals PRELIMINARY STUDY OF LARVAL DEVELOPMENT Oryzias javanicus IN INDONESIA

2017 ◽  
Vol 9 (1) ◽  
pp. 105
Author(s):  
Rachma Puspitasari ◽  
. Suratno
Keyword(s):  
High Salinity ◽  
Larval Fish ◽  
Coastal Region ◽  
Test Organism ◽  
Hatching Rate ◽  
Oryzias Javanicus ◽  
Test Organisms ◽  
Preliminary Study ◽  
Hatching Eggs ◽  
Selection Of

<p><em>Java medaka </em><em><span style="text-decoration: underline;">Oryzias</span> <span style="text-decoration: underline;">javanicus</span> potentially developed as test organism, represents the coastal region because it has a high adaptability in freshwater, brackishwater and marine environments. Utilization of it as a test organism has some obstacles such as lack of number of test organisms with same size or age. The fulfillment of number can be solved if the test organism is cultivated exclusively in the laboratory. This study was a preliminary study to get information about suitable salinity for spawning and hatching. Parameter observed were spawning ability in 0 and 20 ppt and hatching rate of egg among 0. 15 and 30 ppt and development of larval fish in 0 ppt. Result indicated that the fish was be able to spawn in 0 and 20 ppt. Eggs were hatched within 9 days in 30 ppt, faster than in freshwater and 15 ppt. In general, O. javanicus was be able to spawn either in freshwater or seawater, but there are differences in the behavior of fish in the laying of egg. Fish will carried their eggs in the abdomen in freshwater, while 20 ppt salinity fish tends to release the eggs. O. javanicus be able to live and lay eggs on freshwater and seawater. Selection of salinity is adjusted to test requirement in egg phase, pascalarva or adult. In general, breeding of fish easier and faster done in fresh water while hatching eggs take place more quickly in high salinity.</em></p><p><em><br /></em></p><p><strong><em>Keywords: </em></strong><em>Indonesia, Java Medaka, <span style="text-decoration: underline;">Oryzias</span> <span style="text-decoration: underline;">javanicus</span>, test organism</em><strong><em></em></strong></p>

scholarly journals Ecotoxicological assessment of drill cuttings of oil deposits by biotesting methods

2017 ◽  
Author(s):  
Ludmila P. Kapelkina ◽  
Marina V. Chugunova ◽  
Tamara V. Bardina
Keyword(s):  
Higher Plants ◽  
Test Organism ◽  
Aquatic Organisms ◽  
Mineralogical Composition ◽  
Cumulative Impact ◽  
Drill Cuttings ◽  
Ecotoxicological Assessment ◽  
Test Organisms ◽  
Living Organisms ◽  
Biological Methods

Complex multi-component wastes include sewage sludges of treatment plants, industrial and domestic wastes, as well as drill cuttings. In the oil-producing regions, they are the main large-capacity waste. Chemical composition of drill cuttings is conditioned by mineralogical composition of drilled solids and properties of chemicals used in drilling. Since the composition of the latter is not always known (in some cases it can be protected by patent), it is almost impossible to establish the danger or safety of drill cuttings to the environment, based only on the use of chemical analysis methods. Therefore, the only way allowing to assess the cumulative toxicity of drilling waste is biotesting which is based on the determination of reaction of the living organisms to content of the pollutant in the tested sample. While assessing the toxicity of drill cuttings by biological methods, scientists often test the aqueous extract to which the soluble forms of pollutants tend to migrate (eluate biotesting method), and various hydrobionts are used as the tested organisms. However, for adequate assessment of multicomponent solid mediums apart from the eluate methods, it is necessary to use substrate biotesting that provides direct contact of test organism with the tested sample, and thus allows to establish the level of cumulative impact rendered by the contaminants present in the solid substrates, on the living organisms. Therefore we, especially for the purpose of drill cuttings evaluation, have developed substrate methods in which higher plants and natural complex of microorganisms contained in the sludge itself are used as the tested organisms. The goal of our researches was ecotoxicological assessment of drill cuttings in the oil fields of the Western Siberia, applying methods of substrate and eluate biotesting. For this purpose, test organisms at various levels of organization were used: microorganisms, aquatic organisms, higher plants, and mammals. It has been established that the studied drill cuttings are hypotoxic or practically nontoxic. According to current statutory regulations of the Russian Federation, they can be classified within IV and V hazard classes. The results of the conducted researches indicate the advisability of applying, for the purpose of environmental assessment of drill cuttings, of both eluate and substrate biotesting methods.

SURFACTANTS AS FUNGICIDES

1964 ◽  
Vol 42 (10) ◽  
pp. 1335-1347 ◽  
Author(s):  
F. R. Forsyth
Keyword(s):  
Fungicidal Activity ◽  
Surrounding Medium ◽  
Alternaria Solani ◽  
Puccinia Recondita ◽  
Monilinia Fructicola ◽  
Respiration Rates ◽  
Enzyme Systems ◽  
Test Organisms ◽  
Triton X ◽  
Irreparable Damage

The cationic (Hyamine 3500, Cyprex, or dodine, and Triton X-400), anionic (Atlox G-3300 and Santomerse), and non-ionic (Tritons X-100, X-114, and B-1956 as well as Tween 81) surfactants were compared as inhibitors of respiration, as agents promoting the passage of amino acids out of spores into the surrounding medium, and as inhibitors of germination of the spores of one or more of the test organisms Monilinia fructicola, Alternaria solani, Puccinia recondita, and Puccinia coronata. The loss of cell constituents by leakage caused by the various surfactants paralleled their efficacy as fungicides against A. solani. Although the surfactants do cause reduction in respiration rates paralleling their fungicidal activity, the effect of the compounds on respiratory or other enzyme systems is considered to be secondary to the irreparable damage caused to the semipermeable outer membrane of the cytoplasm. The cations Ni++ and Cu++ were compared with the surfactants as inhibitors of respiration and as stimulators of cell leakage.

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