Energy deposition evaluation for ultra-low energy electron beam irradiation systems using calibrated thin radiochromic film and Monte Carlo simulations.

For evaluation of on-site dosimetry and process design in industrial use of ultra-low energy electron beam (ULEB) processes, we evaluate the energy deposition using a thin radiochromic film and a Monte Carlo simulation. The response of film dosimeter was calibrated using a high energy electron beam with an acceleration voltage of 2 MV and alanine dosimeters with uncertainty of 11% at coverage factor 2. Using this response function, the results of absorbed dose measurements for ULEB were evaluated from 10 kGy to 100 kGy as a relative dose. The deviation between the responses of deposit energy on the films and Monte Carlo simulations was within 15%. As far as this limitation, relative dose estimation using thin film dosimeters with response function obtained by high energy electron irradiation and simulation results is effective for ULEB irradiation processes management.

Effect of mass rearing on life history traits and inbreeding depression in the sweetpotato weevil (Coleoptera: Brentidae).

Inadvertent selection is an important genetic process that frequently occurs during laboratory culture and maintenance of biological control agents and other beneficial organisms used in procedures such as the sterile insect technique (SIT). We investigated effects of mass rearing and inbreeding depression on life history traits (number of progeny emerging from host plants, body weight, developmental period, and starvation tolerance) in the sweetpotato weevil, Cylas formicarius elegantulus (Summers) (Coleoptera: Brentidae). The effect of inbreeding was measured by comparing the results obtained from the full-sib crosses with those obtained from nonkin crosses in both wild and mass-reared strains. The mass-reared strain had more progeny than the wild strain. The developmental period of mass-reared strain was shorter than that of the wild strain. Other traits did not differ significantly between strains. We detected inbreeding depression effects on numbers of progeny, and the effects were more pronounced in the mass-reared strain. Hence, laboratory adaptation to mass rearing can produce changes in important biological attributes of sweetpotato weevils.

Assessment of effect of partial sterility on mating performance in sweetpotato weevil (Coleoptera: Curculionidae).

The sterile insect technique (SIT) is widely used to suppress or eradicate target pest insect populations. Although the effectiveness of SIT depends on the ability of released sterile males to mate with and inseminate wild females, the use of gamma radiation to induce sterility negatively impacts reproductive cells as well as somatic cells. Consequently, sterilization by irradiation drastically diminishes mating performance over time. In the current study, we evaluated the effect of irradiation dose intensity on fertility, mating propensity, and mating competitiveness in sweetpotato weevil, Cylas formicarius elegantulus (Summers) (Coleoptera: Curculionidae), for 16 d after irradiation. Although the mating propensity of males irradiated with 200 Gy, the dose currently used to induce complete sterility of C. f. elegantulus in the SIT program in Okinawa Prefecture, was equal to that of nonirradiated weevils for the first 6 d, the mating propensity of males irradiated with doses between of 75 and 150 Gy was maintained for the first 12 d. The potential fertilization ability of weevils was highly depressed compared with the control weevils, even in those treated with 75 Gy. Mating performance was severely compromised in weevils that were irradiated with a dose of 100 Gy or more. These results demonstrate that partial sterilization can be highly advantageous in eradication programs for the sweetpotato weevil. We discuss the advantages of the application of partial irradiation in insect eradication programs.

Effect of irradiation on mating ability in the male sweetpotato weevil (Coleoptera: Curculionidae).

The sterile insect technique (SIT) is widely used for suppressing or eradicating target pest insect populations. The effectiveness of SIT depends on the ability of released sterile males to mate with and inseminate wild females. Irradiation is the effective manner to sterilize mass-reared insects. The negative impacts of this procedure are not limited to damage on reproductive cells. Gamma-radiation damages the epithelial tissue of midgut, which affects the alimentation in insects. Irradiated males alter their mating behavior over time because of the depression of metabolic activity by sterilization. In this study, we evaluated the male mating performance and sexually compatibility of irradiated male Cylas formicarius elegantulus (Summers) (Coleoptera: Curculionidae) with a 200-Gy dose, as currently used in the SIT program in Okinawa Prefecture, throughout 16 d after irradiation in the laboratory. The mating ability of irradiated males did not differ from that of control males for about a week. However, the mating ability of irradiated male drastically decreased thereafter. We consider that irradiated male C. formicarius elegantulus with a 200-Gy dose had no major effect on male mating behavior approximately for a week after irradiation.

Anterior stromal puncture in the treatment of bullous keratopathy: six-month follow-up.

PURPOSE: This study was designed to evaluate the effect of anterior stromal puncture to treat patients with symptomatic bullous keratopathy. METHODS: Fourteen patients with bullous keratopathy who had decreased vision and were or were not awaiting penetrating keratoplasty were evaluated before and 1, 4, 12, and 24 weeks after anterior stromal punctures with a 25-gauge needle. The patients were questioned about pain intensity, foreign-body sensation, and photophobia. Biomicroscopy, esthesiometry, and pachymetry results were evaluated. The results before and after the punctures were compared using the McNemar test, Friedman test, and multiple comparison tests. RESULTS: The comparisons among before and 1, 4, and 12 weeks after the anterior stromal puncture of pain (p = 0.00000556), photophobia (p = 0.0252), foreign-body sensation (p = 0.0000743), and esthesiometry (p = 0.0243) showed significant statistical differences in terms of decreasing symptoms and corneal sensitivity. The average pachymetry did not show statistical difference among before and 1, 4, 12, and 24 weeks after the procedure (p = 0.956). We did not find important differences in terms of corneal neovascularization. CONCLUSION: Anterior stromal puncture is an effective, simple, and low-cost alternative for treating patients with symptomatic bullous keratopathy.