Development of a sonar system to estimate the seafloor subsurface burial depth of a towed gamma-ray spectrometer

A sonar system and image processing method have been developed to continuously estimate the seafloor subsurface burial depth of a gamma-ray spectrometer that is towed along the seafloor by a ship. The towed gamma-ray spectrometer, called the RESQ hose, is an instrument designed to measure radiation levels in seafloor sediments that were contaminated as a result of the accident at the Fukushima-Daiichi nuclear power plant. In situ measurements of subsurface burial depth can increase the accuracy of the radionuclide concentration levels estimated by the RESQ hose by allowing for more accurate modeling of the measurement conditions. The reliability of the system is verified through sea trials performed near the outlet of the Abukuma River. Continuous measurements of burial depth are achieved with an outlier ratio of less than 5%. The burial depths measured by the device show a strong correlation with the acoustic backscatter intensity of side-scan sonar images obtained along the surveyed transect, indicating that burial depth is dependent on sediment type. We examine the influence of burial depth on the conversion factors between detected gamma-ray count rates and the concentrations of 134Cs and 137Cs. For both nuclides, the calculated factors increase by nearly 80% as burial depth increases from 0 to 11 cm. The converted results from the measured 137Cs count rates are compared with a core sample obtained near the transect, with the nearest point within a factor of two of the sampling result

Continuous mapping of radionuclides on the seafloor using a towed gamma ray spectrometer

An instrument to continuously map the distribution of radionuclides on the seafloor has been developed and applied to survey radioactive discharge from the Fukushima Dai-ichi Nuclear Power Plant following the M9.0 earthquake and tsunami that struck the east coast of Japan on March 11 2011. The towed gamma ray spectrometer has been deployed off Fukushima and has to date, been used to monitor radionuclide distribution over a total distance of more than 120 km. Here, we introduce the results of measurements made along three transects within an 80km radius of the plant, focusing on a 22km long transect off Iwaki. While the levels of the natural gamma ray emitter 40K remained constant, the levels of 137Cs and 134Cs were found to vary significantly with location. The in situ measurements show good agreement with laboratory analyzed samples obtained during the survey, indicating that the technique described provides an effective solution for rapid, low cost monitoring of radioactive material on the seafloor.</p

Physically Encrypted Wireless Transmission Based on XOR between Two Data in Terahertz Beams

Future wireless communications require higher security as well as a higher data rate. We have been studying physically secured wireless transmission systems and previously proposed encryption/decryption techniques based on the AND operation caused by coherent detection between two encrypted data sequences on two different terahertz carriers. Furthermore, we suggested that by employing the XOR operation as the decryption, the proposed system can be made more secure because XOR increases the computational complexity for eavesdroppers to recover the plaintext. In this paper, we propose the XOR operation between two data sequences on FSK-modulated terahertz waves. By constructing the XOR encryption transmitters/receivers, which consisted of high-speed wavelength tunable lasers and arrayed uni-traveling-carrier photodiodes (UTC-PDs), we successfully demonstrated the XOR operation between two data sequences on 200 GHz waves from the two transmitters

HPV-16 impairs the subcellular distribution and levels of expression of protein phosphatase 1γ in cervical malignancy

金沢大学医薬保健研究域医学系Background: The high risk Human Papillomavirus (HPV) E6 oncoproteins play an essential role in the development of cervical malignancy. Important cellular targets of E6 include p53 and the PDZ domain containing substrates such as hScrib and Dlg. We recently showed that hScrib activity was mediated in part through recruitment of protein phosphatase 1γ (PP1γ). Methods: Expression patterns of hScrib and PP1γ were assessed by immunohistochemistry of HPV-16 positive cervical intraepithelial neoplasm (CIN), classified as CIN1 (n=4), CIN2 (n=8), CIN3 (n=8), cervical carcinoma tissues (n=11), and HPV-negative cervical tissues (n=8), as well as by subfractionation assay of the HPV-16 positive cervical cancer cell lines, CaSki and SiHa. To explore the effects of the HPV-16 oncoproteins, we have performed siRNA knockdown of E6/E7 expression, and monitored the effects on the expression patterns of hScrib and PP1γ. Results: We show that PP1γ levels in HPV-16 positive tumour cells are reduced in an E6/E7 dependent manner. Residual PP1γ in these cells is found mostly in the cytoplasm as opposed to the nucleus where it is predominantly found in normal cells. We have found a striking concordance with redistribution in the pattern of expression (9/11; 81.8%) and loss of PP1γ expression in HPV-16 positive cervical tumours (2/11; 18.2%). Furthermore, this loss of PP1γ expression and redistribution in the pattern of expression occurs progressively as the lesions develop (8/8; 100%). Conclusion: Together, these results suggest that PP1γ may be a novel target of the HPV-16 oncoproteins and indicate that it might be a potential novel biomarker for HPV-16 induced malignancy. © Seiki et al

A Novel Interaction between hScrib and PP1γ Downregulates ERK Signaling and Suppresses Oncogene-Induced Cell Transformation

<div><p>Previous studies have shown that the cell polarity regulator hScrib interacts with, and consequently controls, the ERK signaling pathway. This interaction occurs through two well-conserved Kinase Interacting Motifs, which allow hScrib to bind ERK1 directly, resulting in a reduction in the levels of phospho-ERK. This suggests that hScrib might recruit a phosphatase to regulate this signaling pathway. Using a proteomic approach we now show that Protein Phosphatase 1γ (PP1γ) is a major interacting partner of hScrib. This interaction is direct and occurs through a conserved PP1γ interaction motif on the hScrib protein, and this interaction appears to be required for hScrib's ability to downregulate ERK phosphorylation. In addition, hScrib also controls the pattern of PP1γ localization, where loss of hScrib enhances the nuclear translocation of PP1γ. Furthermore, we also show that the ability of hScrib to interact with PP1γ is important for the ability of hScrib to suppress oncogene-induced transformation of primary rodent cells. Taken together, these results demonstrate that hScrib acts as a scaffold to integrate the control of the PP1γ and ERK signaling pathways and explains how disruption of hScrib localisation can contribute towards the development of human malignancy.</p> </div