Compact wide-angle capsule endoscopic lens design.

Capsule endoscopes require a high-quality imaging system in terms of the wide field of view (FOV), image brightness, and resolution to provide accurate diagnostic information. However, because of the wide-angle lens design, the first element of the lens inevitably becomes larger in diameter, making it difficult to reduce the overall size of the lens. In this study, the compact wide-angle lens for a capsule endoscope is reported. The proposed system allows the first element to be compact in diameter and increases image quality by utilizing all aspheric surfaces for optical aberration control. The specification of the proposed capsule endoscope lens shows the wide FOV of 160 deg, F-number 2.8, and total track length of 5 mm. In the overall FOV, relative illumination is still over 60%. To achieve a high image quality in the proposed system, the modulation transfer function is over 30% at 180 lp/mm for a${1920} \times {1080}$1920×1080 1/6 inch CMOS image sensor in a pixel size of 1.4 µm.

Use of aggregation pheromone traps increases infestation of adult Riptortus pedestris (Hemiptera: Alydidae) in soybean fields.

BACKGROUND: An aggregation pheromone trap has been used for both monitoring and mass-capture of Riptortus pedestris (Fabricius) in soybean. As the trap's efficacy in reducing the pest population and crop damage is unknown, we evaluated it in small experimental soybean plots using both a before/after and with/without design, and also verified our findings in commercial soybean fields. RESULTS: In experimental plots, total numbers of R. pedestris on plants in the soybean plots were not affected by the trap installation until mid-August. Interestingly, the abundance of adult bugs increased (4.9-9.4 times higher) in September and October. However, compared with the counted bug population in soybean plots, the trap catch rate was low during the autumn period. In commercial fields, trap installation also did not reduce bug population from the field. Placement of traps in plots increased pod and seed damage by 2.7 and 2.2 times, respectively compared with the controls in experimental plots, although no such effect was observed in commercial fields. CONCLUSION: Aggregation pheromone traps did not reduce R. pedestris populations in the field or soybean damage, and even led to an increase in the bug population during autumn. Therefore, traps should not be used as a control measure. © 2018 Society of Chemical Industry.

Oblique scanning 2-photon light-sheet fluorescence microscopy for rapid volumetric imaging.

Light-sheet fluorescence microscopy (LSFM) is a powerful tool for biological studies because it allows for optical sectioning of dynamic samples with superior temporal resolution. However, LSFM using 2 orthogonally co-aligned objectives requires a special sample geometry, and volumetric imaging speed is limited due to physical sample translation. This paper describes an oblique scanning 2-photon LSFM (OS-2P-LSFM) that eliminates these limitations by using a single objective near the sample and a refractive scanning-descanning system. This system also provides improved light-sheet confinement against scattering by using a 2-photon Bessel beam. The OS-2P-LSFM hold promise for studying structural, functional and dynamic aspects of living tissues and organisms because it allows for high-speed, translation-free and scattering-robust 3D imaging of large biological specimens.