scholarly journals The impact of strain diversity and mixed infections on the evolution of resistance to Bacillus thuringiensis

2013 ◽  
Vol 280 (1769) ◽  
pp. 20131497 ◽  
Author(s):  
Ben Raymond ◽  
Denis J. Wright ◽  
Neil Crickmore ◽  
Michael B. Bonsall
Keyword(s):  
Bacillus Thuringiensis ◽  
Transmission Rate ◽  
Diamondback Moth ◽  
Mixed Infections ◽  
Ecological Interactions ◽  
Significant Difference ◽  
Natural Isolates ◽  
Evolution Of Resistance ◽  
Insect Populations ◽  
The Impact

Pesticide mixtures can reduce the rate at which insects evolve pesticide resistance. However, with live biopesticides such as the naturally abundant pathogen Bacillus thuringiensis ( Bt ), a range of additional biological considerations might affect the evolution of resistance. These can include ecological interactions in mixed infections, the different rates of transmission post-application and the impact of the native biodiversity on the frequency of mixed infections. Using multi-generation selection experiments, we tested how applications of single and mixed strains of Bt from diverse sources (natural isolates and biopesticides) affected the evolution of resistance in the diamondback moth, Plutella xylostella, to a focal strain. There was no significant difference in the rate of evolution of resistance between single and mixed-strain applications although the latter did result in lower insect populations. The relative survivorship of Bt- resistant genotypes was higher in the mixed-strain treatment, in part owing to elevated mortality of susceptible larvae in mixtures. Resistance evolved more quickly with treatments that contained natural isolates, and biological differences in transmission rate may have contributed to this. Our data indicate that the use of mixtures can have unexpected consequences on the fitness of resistant and susceptible insects.

Interrelationship of Bacillus thuringiensis Berliner to the Diamondback Moth (Lepidoptera: Noctuidae) and its Primary Parasitoid, Diadegma insulare (Hymenoptera: Ichneumonidae)

1996 ◽  
Vol 31 (4) ◽  
pp. 371-377 ◽  
Author(s):  
S. Ulpah ◽  
L. T. Kok
Keyword(s):  
Bacillus Thuringiensis ◽  
Diamondback Moth ◽  
Parallel Line ◽  
Primary Parasitoid ◽  
Diadegma Insulare ◽  
Significant Difference ◽  
Laboratory Colonies ◽  
The Mean ◽  
Lepidoptera Noctuidae ◽  
Lc50 And Lc90

The interrelationship of Bacillus thuringiensis Berliner var. kurstaki to the diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), and its primary parasitoid, Diadegma insulare Cress. (Hymenoptera: Ichneumonidae), was investigated using laboratory colonies of the insects. The differential response of third-instar diamondback moth, parasitized and unparasitized, to B. thuringiensis (Bt), and the ability of D. insulare to oviposit in Bt-stressed hosts were determined. No significant difference (P > 0.05) was found between the mean mortality of parasitized and unparasitized larvae at each of three concentrations (154, 334, and 2,237 IU/ml) of Bt endotoxin. The three concentrations were equivalent to the LC30, LC50, and LC90 of Bt potency based on preliminary tests. Parallel line assay analysis, however, revealed that the linear dose-response regressions of parasitized and unparasitized larvae were highly significant (P = 0.0001). The LC50s of parasitized versus unparasitized larvae were 373 and 175 IU/ml Bt endotoxin, respectively, indicating that parasitized larvae were less susceptible to Bt. Female D. insulare oviposited in Bt-stressed hosts. The percentage of D. insulare females emerging from Bt-treated larvae (41.4%) was not significantly different from that of untreated larvae (32.0%).

scholarly journals Genetic and Biochemical Characterization of Field-Evolved Resistance to Bacillus thuringiensis Toxin Cry1Ac in the Diamondback Moth, Plutella xylostella

2004 ◽  
Vol 70 (12) ◽  
pp. 7010-7017 ◽  
Author(s):  
Ali H. Sayyed ◽  
Ben Raymond ◽  
M. Sales Ibiza-Palacios ◽  
Baltasar Escriche ◽  
Denis J. Wright
Keyword(s):  
Bacillus Thuringiensis ◽  
Resistance Genes ◽  
Plutella Xylostella ◽  
Biochemical Characterization ◽  
Diamondback Moth ◽  
Field Population ◽  
Laboratory Population ◽  
Binding Studies ◽  
Slow Increase ◽  
Evolution Of Resistance

ABSTRACT The long-term usefulness of Bacillus thuringiensis Cry toxins, either in sprays or in transgenic crops, may be compromised by the evolution of resistance in target insects. Managing the evolution of resistance to B. thuringiensis toxins requires extensive knowledge about the mechanisms, genetics, and ecology of resistance genes. To date, laboratory-selected populations have provided information on the diverse genetics and mechanisms of resistance to B. thuringiensis, highly resistant field populations being rare. However, the selection pressures on field and laboratory populations are very different and may produce resistance genes with distinct characteristics. In order to better understand the genetics, biochemical mechanisms, and ecology of field-evolved resistance, a diamondback moth (Plutella xylostella) field population (Karak) which had been exposed to intensive spraying with B. thuringiensis subsp. kurstaki was collected from Malaysia. We detected a very high level of resistance to Cry1Ac; high levels of resistance to B. thuringiensis subsp. kurstaki Cry1Aa, Cry1Ab, and Cry1Fa; and a moderate level of resistance to Cry1Ca. The toxicity of Cry1Ja to the Karak population was not significantly different from that to a standard laboratory population (LAB-UK). Notable features of the Karak population were that field-selected resistance to B. thuringiensis subsp. kurstaki did not decline at all in unselected populations over 11 generations in laboratory microcosm experiments and that resistance to Cry1Ac declined only threefold over the same period. This finding may be due to a lack of fitness costs expressed by resistance strains, since such costs can be environmentally dependent and may not occur under ordinary laboratory culture conditions. Alternatively, resistance in the Karak population may have been near fixation, leading to a very slow increase in heterozygosity. Reciprocal genetic crosses between Karak and LAB-UK populations indicated that resistance was autosomal and recessive. At the highest dose of Cry1Ac tested, resistance was completely recessive, while at the lowest dose, it was incompletely dominant. A direct test of monogenic inheritance based on a backcross of F1 progeny with the Karak population suggested that resistance to Cry1Ac was controlled by a single locus. Binding studies with 125I-labeled Cry1Ab and Cry1Ac revealed greatly reduced binding to brush border membrane vesicles prepared from this field population.

EFFECTS OF NUCLEAR POLYHEDROSIS VIRUS AND BACILLUS THURINGIENSIS ON WESTERN SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE) 1 AND 2 YEARS AFTER AERIAL APPLICATION

1982 ◽  
Vol 114 (3) ◽  
pp. 281-282 ◽  
Author(s):  
R. F. Shepherd ◽  
T. G. Gray ◽  
J. C. Cunningham
Keyword(s):  
Bacillus Thuringiensis ◽  
Nuclear Polyhedrosis Virus ◽  
Spruce Budworm ◽  
Western Spruce Budworm ◽  
Aerial Application ◽  
Insect Populations ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis ◽  
The Impact ◽  
Selection Of

An understanding of all environmental effects resulting from control actions is important in the selection of a method of managing insect populations. Effects may extend beyond the year of treatment and can modify management decisions. In 1978, a nuclear polyhedrosis virus (NPV) and Bacillus thuringiensis Berliner (B.t.) were tested as aerial spray applications against the western spruce budworm, Choristoneura occidentalis Freeman, on Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco, near Cache Creek, British Columbia. The impact on population densities and on the incidence of NPV was measured in the treated and non-treated areas for 2 vears following the year of application, and is reported here.

Measuring Impact of Stress in Sandwich Generation Caring for Demented Parents

GeroPsych ◽  
2014 ◽  
Vol 27 (4) ◽  
pp. 171-179 ◽  
Author(s):  
Laurence M. Solberg ◽  
Lauren B. Solberg ◽  
Emily N. Peterson
Keyword(s):  
Factor Analysis ◽  
Exploratory Factor Analysis ◽  
Social Worker ◽  
Resource Availability ◽  
Well Being ◽  
Sandwich Generation ◽  
Item Questionnaire ◽  
Significant Difference ◽  
Adult Caregivers ◽  
The Impact

Stress in caregivers may affect the healthcare recipients receive. We examined the impact of stress experienced by 45 adult caregivers of their elderly demented parents. The participants completed a 32-item questionnaire about the impact of experienced stress. The questionnaire also asked about interventions that might help to reduce the impact of stress. After exploratory factor analysis, we reduced the 32-item questionnaire to 13 items. Results indicated that caregivers experienced stress, anxiety, and sadness. Also, emotional, but not financial or professional, well-being was significantly impacted. There was no significant difference between the impact of caregiver stress on members from the sandwich generation and those from the nonsandwich generation. Meeting with a social worker for resource availability was identified most frequently as a potentially helpful intervention for coping with the impact of stress.

SEARCH FOR NATURAL ISOLATES OF Bacillus thuringiensis FOR DEVELOPMENT OF ECOLOGICALLY FRIENDLY BIOLOGICALS

2018 ◽  
Vol 53 (5) ◽  
pp. 1062-1069
Author(s):  
S.D. Grishechkina ◽  
◽  
V.P. Ermolova ◽  
T.A. Romanova ◽  
A.A. Nizhnikov ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Natural Isolates

Implicit and explicit corrective feedback and feedback exposure conditions

2020 ◽  
Vol 4 (1) ◽  
pp. 3-48
Author(s):  
Takehiro Iizuka ◽  
Kimi Nakatsukasa
Keyword(s):  
Explicit Knowledge ◽  
Corrective Feedback ◽  
Significant Difference ◽  
Oral Corrective Feedback ◽  
Post Test ◽  
Picture Description ◽  
Potential Factors ◽  
Implicit And Explicit ◽  
Instructional Settings ◽  
The Impact

This exploratory study examined the impact of implicit and explicit oral corrective feedback (CF) on the development of implicit and explicit knowledge of Japanese locative particles (activity de, movement ni and location ni) for those who directly received CF and those who observed CF in the classroom. Thirty-six college students in a beginning Japanese language course received either recast (implicit), metalinguistic (explicit) or no feedback during an information-gap picture description activity, and completed a timed picture description test (implicit knowledge) and an untimed grammaticality judgement test (explicit knowledge) in a pre-test, immediate post-test and delayed post-test. The results showed that overall there was no significant difference between CF types, and that CF benefited direct and indirect recipients similarly. Potential factors that might influence the effectiveness of CF, such as instructional settings, complexity of target structures and pedagogy styles, are discussed.

Reducing the Social Stigma Associated with Obsessive Compulsive Disorder: A Controlled Trial of an Intervention Program in a Turkish Community Sample

2020 ◽  
Vol 20 (2) ◽  
pp. 101-120
Author(s):  
Ayça Aktaç Gürbüz ◽  
Orçun YORULMAZ ◽  
Gülşah DURNA
Keyword(s):  
Obsessive Compulsive Disorder ◽  
Intervention Program ◽  
Controlled Trial ◽  
Community Sample ◽  
Case Vignette ◽  
Control Group ◽  
Obsessive Compulsive ◽  
Compulsive Disorder ◽  
Significant Difference ◽  
The Impact

Scientific research into the reduction of stigmatization, particularly related to specific problems such as Obsessive-Compulsive Disorder (OCD), is scarce. In the present study, we examine the impact of a video-based antistigma intervention program for OCD in a pretest-posttest control group research. After being randomly assigned to either an intervention (n= 101) or control group (n= 96), the participants reported their attitudes on a hypothetical case vignette before and after OCD vs. Multiple Sclerosis (MS) videos, and again six months later as a follow up assessment. The mixed design analyses for the group comparisons indicated that although there was no significant difference in the measures of the control group, the participants watching the anti-stigma OCD video, in which the focus was psychoeducation and interaction strategies, reported significantly lower scores on social distances and negative beliefs for the case vignettes they read, and this difference was maintained six months later. Then, the present results indicate the effectiveness of our anti-stigma intervention program for OCD. Interventions to reduce stigmatization can also be viewed as effective tools for changing the attitudes of people toward OCD, although further research and applications are needed related to specific disorders if a longlasting impact is to be achieved.

Antecedents And Outcomes Of Qwl Among Employees In Banks

2019 ◽  
Vol 118 (7) ◽  
pp. 1-19
Author(s):  
Geethanjali N ◽  
Parveen Roja M ◽  
Lavanya D
Keyword(s):  
Organizational Climate ◽  
Job Stress ◽  
Work Life ◽  
Working Environment ◽  
Quality Of Work Life ◽  
Quality Of Work ◽  
Significant Difference ◽  
Service Productivity ◽  
The Impact

Quality of work life is the major factor to be considered in working environment of any organization. The performance of employees and the organization lies on the ability of the employees based on working environment. The QWL leads to better working environment which improves the performance of organization. The present study has made an attempt to find the level of factors causing QWL and the impact of outcome of QWL in banks. Since the profile of the banks may be associated with the level of outcomes of QWL, the present study has made an attempt to examine it with the help of one way analysis of variance and t-test. The included outcomes of QWL are job satisfaction, job stress, organizational climate, organizational commitment, employees retention behaviour, service quality employees and service productivity of employees. The highly associated determinants of QWL and the significant difference among the PUSBs and PRSBs have been noticed. The significantly associating important profiles of the banks regarding the existence of outcome of QWL are identified.

Оrganic Meat Production of Broiler Chickens Hubbard Redbro Cross

2020 ◽  
Keyword(s):  
Broiler Chickens ◽  
Raw Materials ◽  
Animal Health ◽  
Meat Products ◽  
Poultry Meat ◽  
Meat Production ◽  
Significant Difference ◽  
Environmentally Safe ◽  
The Impact

This article presents the results of studying the impact of housing and feeding conditions on broiler chickens of Hubbard RedBro cross, as well as the quality of products obtained when using floor and cage content, in a farm. It established that when receiving a mixed feed of own production using feed raw materials grown on a farm without the use of pesticides, a statistically significant decrease in potentially dangerous substances for animal health is recorded. Compared with factory feed, it has reduced the content of pesticides by 14 times, and mercury and arsenic by 24 times, cadmium by five times, and lead by ten times. The results of the study of economic indicators of growing Hubbard RedBro cross broiler chickens, as well as the chemical composition and quality of carcasses, indicated that there was no significant difference between the floor and cell conditions of keeping. Still, the use of a diet based on eco-feeds contributed to a statistically significant decrease in the concentration of toxic metals in the muscles of the poultry of the experimental groups. As a result, it found that the use of the studied compound feed in the diets of broiler chickens increased the indicators of Biosafety and ensured the production of environmentally safe ("organic") poultry meat products.

Characteristics of monitored diabetic patients by glycated haemoglobin (HbA1c)

2016 ◽  
Vol 5 (05) ◽  
pp. 4563
Author(s):  
Tariq A. Zafar
Keyword(s):  
Blood Glucose ◽  
Glycemic Control ◽  
Glycated Haemoglobin ◽  
Poor Glycemic Control ◽  
Diabetic Patients ◽  
Age Group ◽  
Hba1c Test ◽  
Significant Difference ◽  
Tract Infections ◽  
The Impact

Glycated haemoglobin (HbA1c) test indicates the blood glucose levels for the previous two to three months. Using HbA1c test may overcome many of the practical issues and prevent infections such as urinary tract infections (UTIs). The study aimed to evaluate the impact of glycemic control using HbA1c test to understand patient characteristics and UTIs prevalence. Glycemic control was evaluated by measuring HbA1c for a total of 208 diabetes patients who were regularly attending diabetes center in Al-Noor specialist hospital in Makkah.  The results showed that good and moderate glycemic controlled patients were 14.9% and 16.9% respectively while the poor glycemic patients were 68.3%. Among the good improved glycemic control, 83.9% were females, 48.4% were from age group (15-44y). Among the moderately improved glycemic control, 68.4% were females, 54.3% were from age group (45-64 y) with no significant difference. The total number of the patients with positive UTIs was 55 (26.4%) while the total number of patients with negative was UTIs 153 (73.6%). Among the positive UTIs, 76.3% were with poor glycemic control while only 12.3% and 11% were moderate and good improved glycemic control respectively. Among the negative UTIs, 65.3% were with poor glycemic control while only 19% and 15.7% were with moderate and good improved glycemic control respectively.  Prevalence of UTIs among diabetic patients was not significant (p > 0.05). It was concluded that HbA1c was useful monitoring tool for diabetes mellitus and may lead to improved outcomes. Using a HbA1c test may overcome many of the practical issues that affect the blood glucose tests.

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