scholarly journals Resistance to Bt Crops; Influence, mechanisms and management strategies

2016 ◽  
Vol 11 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Esmail Abdalla Elzaki Mohammed
2017 ◽  
Vol 83 (9) ◽  
Author(s):  
Brian R. Pickett ◽  
Asim Gulzar ◽  
Juan Ferré ◽  
Denis J. Wright

ABSTRACT Laboratory selection with Vip3Aa of a field-derived population of Heliothis virescens produced >2,040-fold resistance in 12 generations of selection. The Vip3Aa-selected (Vip-Sel)-resistant population showed little cross-resistance to Cry1Ab and no cross-resistance to Cry1Ac. Resistance was unstable after 15 generations without exposure to the toxin. F1 reciprocal crosses between Vip3Aa-unselected (Vip-Unsel) and Vip-Sel insects indicated a strong paternal influence on the inheritance of resistance. Resistance ranged from almost completely recessive (mean degree of dominance [h] = 0.04 if the resistant parent was female) to incompletely dominant (mean h = 0.53 if the resistant parent was male). Results from bioassays on the offspring from backcrosses of the F1 progeny with Vip-Sel insects indicated that resistance was due to more than one locus. The results described in this article provide useful information for the insecticide resistance management strategies designed to overcome the evolution of resistance to Vip3Aa in insect pests. IMPORTANCE Heliothis virescens is an important pest that has the ability to feed on many plant species. The extensive use of Bacillus thuringiensis (Bt) crops or spray has already led to the evolution of insect resistance in the field for some species of Lepidoptera and Coleoptera. The development of resistance in insect pests is the main threat to Bt crops. The effective resistance management strategies are very important to prolong the life of Bt plants. Lab selection is the key step to test the assumption and predictions of management strategies prior to field evaluation. Resistant insects offer useful information to determine the inheritance of resistance and the frequency of resistance alleles and to study the mechanism of resistance to insecticides.


PLoS Biology ◽  
2021 ◽  
Vol 19 (11) ◽  
pp. e3001409
Author(s):  
Troy Day ◽  
David A. Kennedy ◽  
Andrew F. Read ◽  
David McAdams

Humans are altering biological systems at unprecedented rates, and these alterations often have longer-term evolutionary impacts. Most obvious is the spread of resistance to pesticides and antibiotics. There are a wide variety of management strategies available to slow this evolution, and there are many reasons for using them. In this paper, we focus on the economic aspects of evolution management and ask: When is it economically beneficial for an individual decision-maker to invest in evolution management? We derive a simple dimensionless inequality showing that it is cost-effective to manage evolution when the percentage increase in the effective life span of the biological resource that management generates is larger than the percentage increase in annual profit that could be obtained by not managing evolution. We show how this inequality can be used to determine optimal investment choices for single decision-makers, to determine Nash equilibrium investment choices for multiple interacting decision-makers, and to examine how these equilibrium choices respond to regulatory interventions aimed at stimulating investment in evolution management. Our results are illustrated with examples involving Bacillus thuringiensis (Bt) crops and antibiotic use in fish farming.


1983 ◽  
Vol 14 (2) ◽  
pp. 86-91 ◽  
Author(s):  
Barbara W. Travers

This paper presents strategies for increasing the effectiveness and efficiency of the school-based speech-language pathologist. Various time management strategies are adapted and outlined for three major areas of concern: using time, organizing the work area, and managing paper work. It is suggested that the use of such methods will aid the speech-language pathologist in coping with federal, state, and local regulations while continuing to provide quality therapeutic services.


2020 ◽  
Vol 5 (1) ◽  
pp. 314-325
Author(s):  
Kimberly F. Frazier ◽  
Jessica Collier ◽  
Rachel Glade

Background The aim of this study was to determine the clinical efficacy of combining self-management strategies and a social thinking approach to address the social performance and executive function of an adolescent female with autism spectrum disorder. Method This research examined the effects of a social knowledge training program, “Think Social,” as well as strategies to improve higher order cognitive abilities. Results and Conclusion Although quantitative improvement was not found, several qualitative gains in behavior were noted for the participants of this study, suggesting a benefit from using structured environmental cues of self-management strategies, as well as improved social understanding through social cognitive training.


2015 ◽  
Vol 25 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Ryan W. McCreery ◽  
Elizabeth A. Walker ◽  
Meredith Spratford

The effectiveness of amplification for infants and children can be mediated by how much the child uses the device. Existing research suggests that establishing hearing aid use can be challenging. A wide range of factors can influence hearing aid use in children, including the child's age, degree of hearing loss, and socioeconomic status. Audiological interventions, including using validated prescriptive approaches and verification, performing on-going training and orientation, and communicating with caregivers about hearing aid use can also increase hearing aid use by infants and children. Case examples are used to highlight the factors that influence hearing aid use. Potential management strategies and future research needs are also discussed.


2007 ◽  
Vol 177 (4S) ◽  
pp. 9-9
Author(s):  
Ephrem O. Olweny ◽  
Sean P. Elliott ◽  
Thomas X. Minor ◽  
Jack W. McAninch

2004 ◽  
Vol 171 (4S) ◽  
pp. 42-43 ◽  
Author(s):  
Yair Latan ◽  
David M. Wilhelm ◽  
David A. Duchene ◽  
Margaret S. Pearle

2020 ◽  
Vol 36 (5) ◽  
pp. 777-786 ◽  
Author(s):  
Julia Waldeyer ◽  
Jens Fleischer ◽  
Joachim Wirth ◽  
Detlev Leutner

Abstract. There is substantial evidence that students in higher education who have sophisticated resource-management skills are more successful in their studies. Nevertheless, research shows that students are often not adequately prepared to use resource-management strategies effectively. It is thus crucial to screen and identify students who are at risk of poor resource management (and consequently, reduced academic achievement) to provide them with appropriate support. For this purpose, we extend the validation of a situational-judgment-based instrument called Resource-Management Inventory (ReMI), which assesses resource-management competency (including knowledge of resource-management strategies and the self-reported ability to use this knowledge in learning situations). We evaluated the ReMI regarding factor structure, measurement invariance, and its impact on academic achievement in different study domains in a sample of German first-year students ( N = 380). The results confirm the five-factor structure that has been found in a previous study and indicate strong measurement invariance. Furthermore, taking cognitive covariates into account, the results confirm that the ReMI can predict students’ grades incrementally. Finally, a multi-group analysis shows that the findings can be generalized across different study domains. Overall, we provide evidence for a valid and efficient instrument for the assessment of resource-management competency in higher education.


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