Natural occurrence of sterigmatocystin in in-shell pecans

1977 ◽  
Vol 23 (5) ◽  
pp. 639-641 ◽  
Author(s):  
Harry W. Schroeder ◽  
Hugo Hein Jr.
Keyword(s):  
Natural Occurrence ◽  
Aspergillus Versicolor ◽  
Laboratory Conditions

The natural occurrence of sterigmatocystin (S) in in-shell pecans is reported. Aspergillus versicolor was not isolated from contaminated samples. Incidence of A. flavus and A. glaucus, species known to produce sterigmatocystin under laboratory conditions, was high (43 and 35%, respectively). Isolation data suggest sterigmatocystin may have been produced by one or both of these species.

Genetics of Gibberella fujikuroi. IV. Natural occurrence of compatibility alleles at the mating locus

1983 ◽  
Vol 25 (6) ◽  
pp. 605-608 ◽  
Author(s):  
Gurmel S. Sidhu
Keyword(s):  
Genetic Control ◽  
Gibberella Fujikuroi ◽  
Natural Occurrence ◽  
Mating Types ◽  
Natural Conditions ◽  
Field Isolates ◽  
Laboratory Conditions ◽  
Sexual Compatibility

Gibberella fujikuroi is a heterothallic bipolar fungus and both mat+ and mat− mating types are found in nature but, they rarely cross under natural conditions. However, mat+ and mat− field isolates cross with the two tester strains under laboratory conditions and show variable degrees of sexual compatibility as measured in terms of number of fertile perithecia. Fifteen mat+ and fifteen mat− field isolates were crossed with the two tester strains. Variable degrees of compatibility, ranging from 2.2 to 47.7 perithecia when crossed with 223 (mat−) and 1.1 to 39.9 perithecia when crossed with 80 (mat+), were obtained. The genetic control of six easily distinguishable degrees of compatibility were studied from testcrosses made with the tester strains using random and unordered tetrad analyses. Three alleles in mat+ and three alleles in mat− were distinguished. Frequency of natural occurrence of mat+ and mat− was found to be 27 and 73%, respectively.

scholarly journals Aflatoxin Production in Soybean Varieties Grown in Argentina

1991 ◽  
Vol 54 (7) ◽  
pp. 542-545 ◽  
Author(s):  
VIRGINIA E. FERNÁNDEZ PINTO ◽  
GRACIELA VAAMONDE ◽  
SILVIA B. BRIZZIO ◽  
NICOLÁS APRO
Keyword(s):  
Aspergillus Flavus ◽  
Aflatoxin Production ◽  
Aflatoxin Contamination ◽  
Fungal Isolate ◽  
Natural Occurrence ◽  
Laboratory Conditions

Natural occurrence of aflatoxin contamination on soybeans was investigated. Thirty four samples from the 1986 crop (5.8% positive samples) and 60 samples harvested in 1987 (11.6% positive samples) were analyzed. Aflatoxin levels in positive samples were low, ranging from traces to 36 μg/kg of total aflatoxins. Aflatoxin production by three isolates of Aspergillus flavus/A. parasiticus in 13 soybean varieties has been studied. Soybeans used for cultures were surface disinfected. Levels of aflatoxin formed were dependent both on the toxicogenic potential of the fungal isolate and on the variety of soybeans. Under laboratory conditions variety Prata was the most susceptible and variety SRF the less susceptible to aflatoxin formation.

Sensitivity to Natamycin1 (Pimaricin) of Fungi Isolated in Cheese Warehouses

1977 ◽  
Vol 40 (8) ◽  
pp. 533-536 ◽  
Author(s):  
E. de BOER ◽  
M. STOLK-HORSTHUIS
Keyword(s):  
Ochratoxin A ◽  
Aspergillus Versicolor ◽  
Penicillic Acid ◽  
Experimental Conditions ◽  
Laboratory Conditions ◽  
Penicillium Cyclopium ◽  
Continuous Use ◽  
Natamycin Production ◽  
Penicillium Viridicatum

The sensitivity to natamycin of molds and yeasts isolated in cheese warehouses where natamycin has been used for various periods was determined. After several years of continuous use of natamycin no natamycin-insensitive molds and yeasts were found. In 26 strains of molds isolated in cheese warehouses it was not possible under laboratory conditions to decrease the sensitivity for natamycin. Besides the sensitivity of fungi to natamycin, production of mycotoxins by the isolated molds was investigated. Strains of Penicillium viridicatum, Aspergillus versicolor, and Penicillium cyclopium isolated in the warehouses produced, under experimental conditions, ochratoxin A, sterigmatocystin, and penicillic acid, respectively.

The growth of mica polytypes as studied by conventional and high-resolution TEM

1983 ◽  
Vol 41 ◽  
pp. 174-177
Author(s):  
A. Baronnet ◽  
M. Amouric
Keyword(s):  
Water Pressure ◽  
Point Of View ◽  
Temperature Fields ◽  
Natural Occurrence ◽  
Growth Mechanisms ◽  
Long Period ◽  
High Resolution Tem ◽  
Layer Stacking ◽  
Experimental Works ◽  
Potential Use

The origin of mica polytypes has long been a challenging problem for crystal- lographers, mineralogists and petrologists. From the petrological point of view, interest in this field arose from the potential use of layer stacking data to furnish further informations about equilibrium and/or kinetic conditions prevailing during the crystallization of the widespread mica-bearing rocks. From the compilation of previous experimental works dealing with the occurrence domains of the various mica "polymorphs" (1Mr, 1M, 2M1, 2M2 and 3T) within water-pressure vs temperature fields, it became clear that most of these modifications should be considered as metastable for a fixed mica species. Furthermore, the natural occurrence of long-period (or complex) polytypes could not be accounted for by phase considerations. This highlighted the need of a more detailed kinetic approach of the problem and, in particular, of the role growth mechanisms of basal faces could play in this crystallographic phenomenon.

Human drug taking under controlled laboratory conditions.

1988 ◽  
Author(s):  
Marian W. Fischman ◽  
Richard W. Foltin ◽  
Joseph V. Brady
Keyword(s):  
Laboratory Conditions

Multiple recycling of paperboard: Paperboard characteristics and maximum number of recycling cycles— Part I: Multiple recycling of corrugated base paper

TAPPI Journal ◽  
2019 ◽  
Vol 18 (11) ◽  
pp. 631-638
Author(s):  
FREDERIC KREPLIN ◽  
HANS-JOACHIM PUTZ ◽  
SAMUEL SCHABEL
Keyword(s):  
Compression Test ◽  
Production Capacity ◽  
Strength Properties ◽  
Paper Properties ◽  
Corrugated Board ◽  
Laboratory Conditions ◽  
Base Paper ◽  
Study Results ◽  
Short Span ◽  
Multiple Recycling

Paper for recycling is an important fiber source for the production of corrugated base paper. The change in production capacity toward more and more packaging papers affects the composition of paper for recycling and influences the paper quality. This research project investigated the influence of the multiple recycling of five different corrugated base papers (kraftliner, neutral sulfite semichemical [NSSC] fluting, corrugating medium, testliner 2, and testliner 3) on suspension and strength properties under laboratory conditions. The corrugated board base papers were repulped in a low consistency pulper and processed into Rapid-Köthen laboratory sheets. The sheets were then recycled up to 15 times in the same process. In each cycle, the suspension and the paper properties were recorded. In particular, the focus was on corrugated board-specific parameters, such as short-span compression test, ring crush test, corrugating medium test, and burst. The study results indicate how multiple recycling under laboratory conditions affects fiber and paper properties.

Mechanoactivation Of Rice Husk Ash In Laboratory Conditions

2019 ◽  
pp. 20-26
Keyword(s):  
Mechanical Activation ◽  
Rice Husk ◽  
Amorphous Silica ◽  
Silicon Oxide ◽  
Rice Husk Ash ◽  
Pozzolanic Activity ◽  
Maximum Solubility ◽  
Laboratory Conditions ◽  
Before And After ◽  
Mineral Additive

In many rice producing countries of the world, including in Vietnam, various research aimed at using rice husk ash (RHA) as a finely dispersed active mineral additive in cements, concrete and mortars are being conducted. The effect of the duration of the mechanoactivation of the RHA, produced under laboratory conditions in Vietnam, on its pozzolanic activity were investigated in this study. The composition of ash was investigated by laser granulometry and the values of indicators characterizing the dispersion of its particles before and after mechanical activation were established. The content of soluble amorphous silicon oxide in rice husk ash samples was determined by photocolorimetric analysis. The pizzolanic activity of the RHA, fly ash and the silica fume was also compared according to the method of absorption of the solution of the active mineral additive. It is established that the duration of the mechanical activation of rice husk ash by grinding in a vibratory mill is optimal for increasing its pozzolanic activity, since it simultaneously results in the production of the most dispersed ash particles with the highest specific surface area and maximum solubility of the amorphous silica contained in it. Longer grinding does not lead to further reduction in the size of ash particles, which can be explained by their aggregation, and also reduces the solubility of amorphous silica in an aqueous alkaline medium.

Determination of natural radionuclides in waste generated in the potable water treatment plants of the Zona da Mata of the state of Pernambuco- Brazil

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Adriana Muniz De Almeida Albuquerque
Keyword(s):  
Water Treatment ◽  
Potable Water ◽  
Natural Radionuclides ◽  
The United States ◽  
Radioactive Material ◽  
Human Consumption ◽  
Radiological Protection ◽  
Natural Occurrence ◽  
Water Treatment Plants ◽  
Potable Water Treatment

The water purification procedure aims to obtain a product appropriate for human consumption, minimizing the presence of contaminants and toxic substances present in the water. Among these contaminants, some radionuclides of natural origin, such as uranium, thorium and their descendants, have been identified. Studies have shown that the stages of purification are quite effective in removing the radionuclides contained in water. The removal is due to co-precipitation of the radionuclides with the suspended materials and the precipitated material is accumulated and characterized as a Technologically Concentrated Natural Occurrence Radioactive Material (TENORM) by the United States Environmental Protection Agency (USEPA). This residue can present significant levels of radioactivity and, when discarded in the environment without any treatment, can generate a problem of environmental impact and a risk to the health of the population. In this way, some gamma emitters of the series of U, Th and the K-40 were determined in the residues generated at the Potable Water Treatment Plants – PWTPs in six municipalities of Pernambuco. The results obtain corroborate the classification of the residues generated in the PWTPs as concentrators of the radioactive components contained in the water supplied to the system and reinforce the need for the release to the environment, which is the usual way of disposal of this waste, to be carried out only after considering the radiological protection standards established.

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