The effect of gamma radiation on larval resistance to Bacillus thuringiensis infection

Summary The codling moth [Cydia pomonella L. (Lepidoptera: Tortricidae)] is the main pest in most apple orchards in Syria. It causes billions of dollars in loss of fruit crops every year. The present work examined the effects of gamma radiation and Bacillus thuringiensis (BT) on F1 progeny of C. pomonella. The experimental design was based on two factors, namely F1 offspring produced by males irradiated at a dose of 150 Gy, and artificial diet of BT-treated larvae. The first offspring of unirradiated and irradiated C. pomonella males, F1, were from parents treated with a commercial formulation of Bacillus thuringiensis BT (Dipel® 2X). F1 progeny of unirradiated was significantly less susceptible to BT than that of irradiated parents. The results showed high mortality in F1 progeny of C. pomonella when gamma radiation and BT were applied together. The LC50 in F1 progeny was 2.5 ppm for irradiated parents, while it was 13 ppm for unirradiated ones. A significant reduction in the fecundity and egg hatchability of F1 progeny of irradiated parents compared to unirradiated ones was observed. This study demonstrated that for F1 progeny the combination between Inherited Sterility Technique and BT can be useful to achieve an integrated pest management program of codling moth.

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Study on using gamma radiation to inactivate Bacillus thuringiensis spores in biopesticide

Nuclear Science and Technology ◽

10.53747/jnst.v7i1.118 ◽

2021 ◽

Vol 7 (1) ◽

pp. 43-48

Author(s):

Thi Thom Nguyen ◽

Van Binh Nguyen ◽

Bang Diep Tran ◽

Dang Sang Hoang ◽

Xuan An Tran ◽

...

Keyword(s):

Bacillus Thuringiensis ◽

Gamma Radiation ◽

Insecticidal Activity ◽

Animal Health ◽

Heliothis Armigera ◽

Optimal Dose ◽

Living Cells ◽

Soil Microflora ◽

Insecticidal Effect ◽

Bt Toxins

Bacillus thuringiensis (Bt) produces different types of toxin that have potent and specific insecticidal activity. In recent years, Bt toxins have been used as the safe biological control agents to protect crops replacing for chemical insecticides. Bt-based biopesticides that have been commercialized as the alternative products to control pests and insects for sustainable agriculture, contain toxicity crystals and a significant number of spores that affects to the soil microflora. These uncontrollable changes may contaminate the cultivation soil, and eventually cause adverse effects to human and animal health. Therefore, the living cells and spores existing in the Bt-biopesticides should be controlled. This study evaluates the effects of gamma radiation on spore viability, germination and growth of the existing spores after spraying on the soil and the insecticidal effectiveness of a Bt-based biopesticide (VBT) against lepidoptera larvae. We attempted to identify the optimal dose that couldinactivate Bt spores but the toxicity of Bt still retain highly. The results revealed that the dose of 20 kGy is enough to control all living cells and spores in the product that consists of approximately 5.2 × 107 spores in the initial VBT. Though the growth of existing spores after spraying on the soil reduced by 85% or more by irradiation, their insecticidal activity against Heliothis armigera larvae reduced by 20-30% only as compared to that of the initial VBT. It suggested that gamma irradiation can be applied as useful way to control the living cells and spores existing in the commercial Bt-based bio-pesticides, and the radiation dose of 20 kGy is enough to kill all spores in VBT, but still kept its insecticidal effect for Heliothis armigera larvae

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Effects of sterilization modes on the mechanical strengths of plaster of paris implants

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100156432 ◽

1989 ◽

Vol 47 ◽

pp. 890-891

Author(s):

K. Cowden ◽

B. Giammara ◽

T. Devine ◽

J. Hanker

Keyword(s):

Gamma Radiation ◽

Calcium Sulfate ◽

Significant Loss ◽

Potassium Sulfate ◽

Limiting Factors ◽

Radiation Sterilization ◽

Plaster Of Paris ◽

Hardness Tester ◽

Dry Heat ◽

Calcium Sulfate Hemihydrate

Plaster of Paris (calcium sulfate hemihydrate, CaSO4. ½ H2O) has been used as a biomedical implant material since 1892. One of the primary limiting factors of these implants is their mechanical properties. These materials have low compressive and tensile strengths when compared to normal bone. These are important limiting factors where large biomechanical forces exist. Previous work has suggested that sterilization techniques could affect the implant’s strength. A study of plaster of Paris implant mechanical and physical properties to find optimum sterilization techniques therefore, could lead to a significant increase in their application and promise for future use as hard tissue prosthetic materials.USG Medical Grade Calcium Sulfate Hemihydrate Types A, A-1 and B, were sterilized by dry heat and by gamma radiation. Types A and B were additionally sterilized with and without the setting agent potassium sulfate (K2SO4). The plaster mixtures were then moistened with a minimum amount of water and formed into disks (.339 in. diameter x .053 in. deep) in polyethylene molds with a microspatula. After drying, the disks were fractured with a Stokes Hardness Tester. The compressive strengths of the disks were obtained directly from the hardness tester. Values for the maximum tensile strengths σo were then calculated: where (P = applied compression, D = disk diameter, and t = disk thickness). Plaster disks (types A and B) that contained no setting agent showed a significant loss in strength with either dry heat or gamma radiation sterilization. Those that contained potassium sulfate (K2SO4) did not show a significant loss in strength with either sterilization technique. In all comparisons (with and without K2SO4 and with either dry heat or gamma radiation sterilization) the type B plaster had higher compressive and tensile strengths than that of the type A plaster. The type A-1 plaster however, which is specially modified for accelerated setting, was comparable to that of type B with K2SO4 in both compressive and tensile strength (Table 1).

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Running wheel activity of rats tested under varying conditions of food deprivation thirty-three days after acute exposure to 1,050 r of gamma radiation.

PsycEXTRA Dataset ◽

10.1037/e433072004-001 ◽

1959 ◽

Author(s):

A. A. McDowell ◽

W. Lynn Brown

Keyword(s):

Gamma Radiation ◽

Food Deprivation ◽

Acute Exposure ◽

Running Wheel ◽

Wheel Activity

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Use of the comet assay to measure DNA damage in cells exposed to photosensitizers and gamma radiation

Journal de Chimie Physique ◽

10.1051/jcp:1999122 ◽

1999 ◽

Vol 96 (1) ◽

pp. 143-146 ◽

Cited By ~ 6

Author(s):

J.-P. Pouget ◽

J.-L. Ravanat ◽

T. Douki ◽

M.-J. Richard ◽

J. Cadet

Keyword(s):

Dna Damage ◽

Comet Assay ◽

Gamma Radiation ◽

In Cells

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National primary standard of air kerma, air kerma rate, exposure, exposure rate and energy flux for X-rays and gamma radiation GET 8-2019

Izmeritel`naya Tekhnika ◽

10.32446/0368-1025it.2020-8-8-12 ◽

2020 ◽

pp. 8-12

Author(s):

Alexandr V. Oborin ◽

Anna Y. Villevalde ◽

Sergey G. Trofimchuk

Keyword(s):

Gamma Radiation ◽

Energy Flux ◽

Primary Standard ◽

Average Energy ◽

Ion Pair ◽

X Rays ◽

Exposure Rate ◽

Ionization Chambers ◽

Air Kerma ◽

Air Kerma Rate

The results of development of the national primary standard of air kerma, air kerma rate, exposure, exposure rate and energy flux for X-rays and gamma radiation GET 8-2011 in 2019 are presented according to the recommendations of the ICRU Report No. 90 “Key Data for Ionizing-Radiation Dosimetry: Measurement Standards and Applications”. The following changes are made to the equations for the units determination with the standard: in the field of X-rays, new correction coefficients of the free-air ionization chambers are introduced and the relative standard uncertainty of the average energy to create an ion pair in air is changed; in the field of gamma radiation, the product of the average energy to create an ion pair in air and the electron stopping-power graphite to air ratio for the cavity ionization chambers is changed. More accurate values of the units reproduced by GET 8-2019 are obtained and new metrological characteristics of the standard are stated.

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