Factors affecting aflatoxin contamination of cottonseed I. Contamination of cottonseed withAspergillus flavusat harvest and during storage

1977 ◽  
Vol 54 (6) ◽  
pp. 219-224 ◽  
Author(s):  
Thota A. P. Hamsa ◽  
John C. Ayres
2021 ◽  
pp. 587-628
Author(s):  
Ranajit Bandyopadhyay ◽  
◽  
Alejandro Ortega-Beltran ◽  
Matieyedou Konlambigue ◽  
Lawrence Kaptoge ◽  
...  

Aflatoxins pose a significant public health risk, decrease productivity and profitability and hamper trade. To minimize aflatoxin contamination a biocontrol technology based on atoxigenic strains of Aspergillus flavus that do not produce aflatoxin is used widely in the United States. The technology, with the generic name Aflasafe, has been improved and adapted for use in Africa. Aflasafe products have been developed or are currently being developed in 20 African countries. Aflatoxin biocontrol is being scaled up for use in several African countries through a mix of public, private, and public-private interventions. Farmers in several countries have commercially treated nearly 400,000 ha of maize and groundnut achieving >90% reduction in aflatoxin contamination. This chapter summarizes the biology of aflatoxin-producing fungi and various factors affecting their occurence, including climate change. Various management practices for aflatoxin mitigation are then discussed. These include biological control, which is increasingly being adopted by farmers in several countries. We discuss biocontrol product development and commercialization in various African countries. Subsequently, we highlight some barriers to adoption and other challenges.


2018 ◽  
Vol 11 (3) ◽  
pp. 437-446 ◽  
Author(s):  
A.M. Johnson ◽  
J.R. Fulton ◽  
T. Abdoulaye ◽  
B. Ayedun ◽  
N.J.O. Widmar ◽  
...  

Aflatoxin is a potent mycotoxin that can cause cancer and death and is associated with stunted growth. Prevalence of aflatoxin is widespread in Africa negatively impacting health and trade. Aflasafe is a biological control product that can be applied to maize or groundnut fields to reduce aflatoxin contamination. This study examines the levels of aflatoxin and Aflasafe awareness and understanding among smallholder maize farmers in Nigeria. In addition, the factors affecting Aflasafe purchase patterns and sustained usage over multiple growing seasons by farmers were evaluated. In-person surveys of 902 Nigerian smallholder farmers were conducted during October and November of 2016. This work contributes to the existing literature by documenting awareness levels of aflatoxin and use of Aflasafe as a control in Nigeria. Results suggest that the level of awareness of aflatoxin was very high in states where Aflasafe was promoted as an intervention for aflatoxin management. In Kaduna state, the region with the longest intervention, there was a consistent increase in the usage of Aflasafe since its introduction in 2010. Furthermore, farmers who purchase Aflasafe bundled (combined) with other inputs were more likely to persist in using the product. Education was found to significantly and positively impact continued usage of Aflasafe. Continued interventions, promotion and general education of the public are recommended for increased awareness, trial, and adoption of Aflasafe in Nigeria.


Author(s):  
F. A. Heckman ◽  
E. Redman ◽  
J.E. Connolly

In our initial publication on this subject1) we reported results demonstrating that contrast is the most important factor in producing the high image quality required for reliable image analysis. We also listed the factors which enhance contrast in order of the experimentally determined magnitude of their effect. The two most powerful factors affecting image contrast attainable with sheet film are beam intensity and KV. At that time we had only qualitative evidence for the ranking of enhancing factors. Later we carried out the densitometric measurements which led to the results outlined below.Meaningful evaluations of the cause-effect relationships among the considerable number of variables in preparing EM negatives depend on doing things in a systematic way, varying only one parameter at a time. Unless otherwise noted, we adhered to the following procedure evolved during our comprehensive study:Philips EM-300; 30μ objective aperature; magnification 7000- 12000X, exposure time 1 second, anti-contamination device operating.


Author(s):  
Christine M. Dannels ◽  
Christopher Viney

Processing polymers from the liquid crystalline state offers several advantages compared to processing from conventional fluids. These include: better axial strength and stiffness in fibers, better planar orientation in films, lower viscosity during processing, low solidification shrinkage of injection moldings (thermotropic processing), and low thermal expansion coefficients. However, the compressive strength of the solid is disappointing. Previous efforts to improve this property have focussed on synthesizing stiffer molecules. The effect of microstructural scale has been overlooked, even though its relevance to the mechanical and physical properties of more traditional materials is well established. By analogy with the behavior of metals and ceramics, one would expect a fine microstructure (i..e. a high density of orientational defects) to be desirable.Also, because much microstructural detail in liquid crystalline polymers occurs on a scale close to the wavelength of light, light is scattered on passing through these materials.


1990 ◽  
Vol 54 (11) ◽  
pp. 638-643 ◽  
Author(s):  
PC Damiano ◽  
ER Brown ◽  
JD Johnson ◽  
JP Scheetz

1976 ◽  
Vol 7 (4) ◽  
pp. 207-219 ◽  
Author(s):  
Constance P. DesRoches

A statistical review provides analysis of four years of speech therapy services of a suburban school system which can be used for comparison with other school system programs. Included are data on the percentages of the school population enrolled in therapy, the categories of disabilities and the number of children in each category, the sex and grade-level distribution of those in therapy, and shifts in case-load selection. Factors affecting changes in case-load profiles are identified and discussed.


2019 ◽  
Vol 62 (5) ◽  
pp. 1243-1257 ◽  
Author(s):  
Peggy Pik Ki Mok ◽  
Holly Sze Ho Fung ◽  
Vivian Guo Li

Purpose Previous studies showed early production precedes late perception in Cantonese tone acquisition, contrary to the general principle that perception precedes production in child language. How tone production and perception are linked in 1st language acquisition remains largely unknown. Our study revisited the acquisition of tone in Cantonese-speaking children, exploring the possible link between production and perception in 1st language acquisition. Method One hundred eleven Cantonese-speaking children aged between 2;0 and 6;0 (years;months) and 10 adolescent reference speakers participated in tone production and perception experiments. Production materials with 30 monosyllabic words were transcribed in filtered and unfiltered conditions by 2 native judges. Perception accuracy was based on a 2-alternative forced-choice task with pictures covering all possible tone pair contrasts. Results Children's accuracy of production and perception of all the 6 Cantonese tones was still not adultlike by age 6;0. Both production and perception accuracies matured with age. A weak positive link was found between the 2 accuracies. Mother's native language contributed to children's production accuracy. Conclusions Our findings show that production and perception abilities are associated in tone acquisition. Further study is needed to explore factors affecting production accuracy in children. Supplemental Material https://doi.org/10.23641/asha.7960826


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