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Background: The potential risk and association of bovine leukemia virus (BLV) with human remains controversial as it has been reported to be both positive and negative in human breast cancer and blood samples. Therefore, establishing the presence of BLV in comprehensive human clinical samples in different geographical locations is essential. Result: In this study, we examined the presence of BLV proviral DNA in human blood and breast cancer tissue specimens from Japan. PCR analysis of BLV provirus in 97 Japanese human blood samples and 23 breast cancer tissues showed negative result for all samples tested using long-fragment PCR and highly-sensitive short-fragment PCR amplification. No IgG and IgM antibodies were detected in any of the 97 human serum samples using BLV gp51 and p24 indirect ELISA test. Western blot analysis also showed negative result for IgG and IgM antibodies in all tested human serum samples. Conclusion: Our results indicate that Japanese human specimens including 97 human blood, 23 breast cancer tissues, and 97 serum samples were negative for BLV. [ABSTRACT FROM AUTHOR]

Ground-Based Augmentation System (GBAS) is a GNSS augmentation system that meets International Civil Aviation Organization (ICAO) requirements to support precision approach and landing. GBAS is based on local differential GNSS technique with reference stations located around an airport to provide necessary integrity and accuracy. The performance of the GBAS system can be affected by gradient in the ionospheric delay between aircraft and reference stations. A nominal ionospheric gradient, which is bounded by a conservative error bound, is represented by a parameter σvig. The parameter σvig is commonly determined using station pair to GNSS Continuous Operating Reference Station (CORS) data. The station-pair method is susceptible to doubling of the estimation error of receiver inter-frequency bias (IFB) and is not suitable with the CORS conditions in Indonesia. We propose a satellite-pair method that is found to be more suitable for the CORS network over Indonesia which is centered in Java and Sumatra islands. An overall value of σvig (5.21 mm/km) was obtained using this method along with preliminary results of a comparison of σvig from Java and Sumatra islands. [ABSTRACT FROM AUTHOR]

Traveling ionospheric disturbances (TIDs) were observed over Japan by using Global Navigation Satellite System (GNSS) receiver network data after the eruption of Hunga Tonga-Hunga Ha'apai in Tonga on 15 January 2022. Two types of TIDs with different characteristics were observed as perturbation in the total electron content (TEC). The first one arrived at Japan which are located about 7800 km away from Hunga Tonga-Hunga Ha'apai about 3 h after the eruption. The amplitude was about ± 0.5 TECU. The wavefronts was in the NNE–SSW direction and propagated in the WNW direction (– 69 ∘ counter-clockwise from the north) at 250 m s - 1 . The wavelength was estimated as 400 km. The second one arrived at Japan about 7 h after the eruption. The amplitude was about ± 1.0 TECU. The wavefronts was in the NE–SW direction and propagated in the NW direction (– 53 ∘ counter-clockwise from the north) at 270 m s - 1 . The wavelength was longer than the first one and was estimated as 800 km. The first one were associated with ionospheric irregularities represented by the rate of TEC index (ROTI). In contrast, the second one did not have irregularities all over the TIDs, but in only a limited region. The arrival of the first TID was too early for the atmospheric acoustic waves to arrive, while the arrival of the second TIDs approximately coincided with the arrival of surface pressure enhancement. To understand the mechanisms of the TIDs, further studies with wide-area observations as well as numerical calculations are necessary. TIDs and ionospheric irregularities after volcanic eruption could be threats to GNSS-based systems especially for those which utilize carrier-phase measurements. [ABSTRACT FROM AUTHOR]

Body position changes at the workstation complement the eye position for better viewing of the visual target. The adjustments of eye position and body posture to various screen height settings are used to determine the motions caused by interactions among various body parts. The viewing angle in individuals using a computer game requiring constant visual monitoring is decided by inclination of the neck and the eye. Thoracic bending has a small effect on the visual angle. A significant correlation is obtained between viewing distance and trunk inclination.

Distance between keyboard and the cathode ray tube (CRT) influences the ocular surface area (OSA). No significant difference exists in average OSA in different visual display terminal (VDT) workstations. OSA increases when looking at the CRT and decreases when viewing the keyboard, with an increase in distance between CRT and the keyboard. Data suggests that the desk height should correspond to user's height and CRT should be placed closer to the keyboard as it reduces the OSA in VDT workstation users. The vertical orientation of gaze provides visual ease.

In this study, the crack initiation and propagation behaviors of the γ' layer in nitrided ultra-low carbon steel subjected to monotonic and cyclic tensile tests were investigated to comprehensively understand the deformation and fracture behavior of the Fe4N (γ') phase. A γ' layer with a grain size of approximately 2 μm was successfully formed on the ferrite matrix through nitriding treatment by controlling the nitriding potential. After the monotonic tensile test until fracture, numerous microcracks were generated in the γ' layer, and a few macrocracks were detected in the ferrite matrix propagated from the γ' layer. The microcracks were initiated from the γ' layer/ferrite matrix boundary and propagated to the surface along the {100}γ' in the grain or grain boundary during the monotonic tensile test. During the cyclic tensile test, after applying yield stress up to 105 cycles, microcracks were initiated from the voids around the surface and propagated to inside of the specimen along {111}γ' in the grain or grain boundary. The results demonstrated that, in the γ' layer, the cracks propagated with the cleavage fracture on {100}γ' during the monotonic tensile test, and slipping-off occurred as a result of activating {111} < 1–10 > slip systems during the cyclic tensile test. It is most likely that the macrocracks propagate in the ferrite grain where {100}α is parallel to the microcrack plane in the γ' layer and lies in the direction perpendicular to the tensile direction. [ABSTRACT FROM AUTHOR]

Asymmetric Lewis acid-catalyzed Diels-Alder reaction of chiral, unsymmetrical maleates yields optically-active, unsymmetrical cis-cyclohexane-1,2-dicarboxylate derivatives. The high diastereoselectivity of the reaction indicates an attractive pi-pi interaction between the maleate C double bond C and the phenyl groups of chiral supplements such as alpha-phenethyl and trans-2-phenylcyclohexyl groups.