Growth monitoring and classification of rice fields using multitemporal RADARSAT-2 full-polarimetric data

Spaceborne synthetic aperture radar (SAR) can be used for agricultural monitoring. In this study, three single-polarimetric and four full-polarimetric observation data sets were analysed. A rice paddy field in northern Japan was used as the study site; the data for this site were obtained using RADARSAT-2, which carries a full-polarimetric C-band SAR. Soybean and grass fields were also present within the paddy fields. The temporal change in the backscattering coefficient of the rice paddy fields for the single-polarization data agreed with the temporal change obtained for a rice growth model based on radiative transfer theory. A three-component decomposition approach was applied to the full-polarimetric data. With each rice growth stage, the volume scattering component ratio increased, whereas the surface scattering component ratio generally decreased. The soybean and grass fields showed a smaller double-bounce scattering component than the rice fields for all the acquired data. The results of this study show that multitemporal observation by full-polarimetric SAR has great potential to be utilized for estimating rice-planted areas and monitoring rice growth.     

Molecular Mechanisms and Tumor Biological Aspects of 5-Fluorouracil Resistance in HCT116 Human Colorectal Cancer Cells

5-Fluorouracil (5-FU) is a cornerstone drug used in the treatment of colorectal cancer (CRC). However, the development of resistance to 5-FU and its analogs remain an unsolved problem in CRC treatment. In this study, we investigated the molecular mechanisms and tumor biological aspects of 5-FU resistance in CRC HCT116 cells. We established an acquired 5-FU-resistant cell line, HCT116R^F10. HCT116R^F10 cells were cross-resistant to the 5-FU analog, fluorodeoxyuridine. In contrast, HCT116R^F10 cells were collaterally sensitive to SN-38 and CDDP compared with the parental HCT16 cells. Whole-exome sequencing revealed that a cluster of genes associated with the 5-FU metabolic pathway were not significantly mutated in HCT116 or HCT116R^F10 cells. Interestingly, HCT116R^F10 cells were regulated by the function of thymidylate synthase (TS), a 5-FU active metabolite 5-fluorodeoxyuridine monophosphate (FdUMP) inhibiting enzyme. Half of the TS was in an active form, whereas the other half was in an inactive form. This finding indicates that 5-FU-resistant cells exhibited increased TS expression, and the TS enzyme is used to trap FdUMP, resulting in resistance to 5-FU and its analogs.     

RETRACTED ARTICLE: Single-Phase <Emphasis Type="Italic">β</Emphasis>-Zn<Subscript>4</Subscript>Sb<Subscript>3</Subscript> Prepared by a Mechanical Grinding Method

Single-phase β-Zn₄Sb₃ materials were prepared by mechanical grinding (MG). Source materials for the Zn₄Sb₃ ingots were prepared using three different processes after the direct melting of constituent elements. In process 1, the ingot was obtained by quenching the melt in water within an evacuated quartz ampoule. In process 2, the ingot was heat-treated for 100 h at 723 K after process 1. In process 3, the ingot was heat-treated for a total of 200 h in two stages at 723 K and 673 K after process 1. The resultant ingots were mechanically ground and sintered at 623 K by hot pressing. The sintered materials were characterized by x-ray diffraction, differential thermal analysis (DTA), and thermoelectric property measurements. The thermal conductivity of the sintered materials was 0.88 W m⁻¹ K⁻¹ at room temperature, being slightly lower than that reported for the materials prepared by a conventional method. Results indicate that the dimensionless figure of merit of the single-phase β-Zn₄Sb₃ ranged from 1.06 to 1.31 at 573 K.     

Examination of Surfactant Protein D as a Biomarker for Evaluating Pulmonary Toxicity of Nanomaterials in Rat

This work studies the relationship between lung inflammation caused by nanomaterials and surfactant protein D (SP-D) kinetics and investigates whether SP-D can be a biomarker of the pulmonary toxicity of nanomaterials. Nanomaterials of nickel oxide and cerium dioxide were classified as having high toxicity, nanomaterials of two types of titanium dioxides and zinc oxide were classified as having low toxicity, and rat biological samples obtained from 3 days to 6 months after intratracheal instillation of those nanomaterials and micron-particles of crystalline silica were used. There were different tendencies of increase between the high- and low-toxicity materials in the concentration of SP-D in bronchoalveolar-lavage fluid (BALF) and serum and in the expression of the SP-D gene in the lung tissue. An analysis of the receiver operating characteristics for the toxicity of the nanomaterials by SP-D in BALF and serum showed a high accuracy of discrimination from 1 week to 3 or 6 months after exposure. These data suggest that the differences in the expression of SP-D in BALF and serum depended on the level of lung inflammation caused by the nanomaterials and that SP-D can be biomarkers for evaluating the pulmonary toxicity of nanomaterials.     

Detection and discrimination of aquacultural facilities in Matsushima Bay,Japan, for integrated coastal zone management and marine spatial planning using full polarimetric L-band airborne synthetic aperture radar

Integrated coastal zone management (ICZM) and marine spatial planning (MSP) have been proposed for sustainable development of coastal zones. To implement ICZM and MSP, there is a need to establish database and informational networks to collect, share and disseminate information of the present situation of coastal zones. One permanent and concentrated use of coastal zones is hosting aquacultural facilities. This study aimed to develop a method to detect and discriminate aquacultural facilities in Matsushima Bay, Japan, using L-band polarimetric and interferometric airborne synthetic aperture radar (Pi-SAR-L2). Three-component-scattering model and eigenvalue–eigenvector decomposition were applied. The volume-scattering component images of the three-component-scattering model showed raft, longline, and rack aquacultural facilities from the sea surface in good contrast. The double-bounce-scattering component percentage discriminated rack aquacultural facilities from raft and longline aquacultural facilities. The size difference in the raft and longline aquacultural facilities was helpful for discriminating the type.     

Usefulness of myeloperoxidase as a biomarker for the ranking of pulmonary toxicity of nanomaterials

Background

In order to examine whether myeloperoxidase (MPO) can be a useful marker for evaluating the pulmonary toxicity of nanomaterials, we analyzed MPO protein in bronchoalveolar lavage fluid (BALF) samples obtained from previous examinations of a rat model. In those examinations we performed intratracheal instillation exposures (dose: 0.2–1.0 mg) and inhalation exposures (exposure concentration: 0.32–10.4 mg/m³) using 9 and 4 nanomaterials with different toxicities, respectively. Based on those previous studies, we set Nickel oxide nanoparticles (NiO), cerium dioxide nanoparticles (CeO₂), multi wall carbon nanotubes with short or long length (MWCNT (S) and MWCNT (L)), and single wall carbon nanotube (SWCNT) as chemicals with high toxicity; and titanium dioxide nanoparticles (TiO₂ (P90) and TiO₂ (Rutile)), zinc oxide nanoparticles (ZnO), and toner with external additives including nanoparticles as chemicals with low toxicity. We measured the concentration of MPO in BALF samples from rats from 3 days to 6 months following a single intratracheal instillation, and from 3 days to 3 months after the end of inhalation exposure.

Results

Intratracheal instillation of high toxicity NiO, CeO_2, MWCNT (S), MWCNT (L), and SWCNT persistently increased the concentration of MPO, and inhalation of NiO and CeO₂ increased the MPO in BALF. By contrast, intratracheal instillation of low toxicity TiO₂ (P90), TiO₂ (Rutile), ZnO, and toner increased the concentration of MPO in BALF only transiently, and inhalation of TiO₂ (Rutile) and ZnO induced almost no increase of the MPO. The concentration of MPO correlated with the number of total cells and neutrophils, the concentration of chemokines for neutrophils (cytokine-induced neutrophil chemoattractant (CINC)-1 and heme oxygenase (HO)-1), and the activity of released lactate dehydrogenase (LDH) in BALF. The results from the receiver operating characteristics (ROC) for the toxicity of chemicals by the concentration of MPO proteins in the intratracheal instillation and inhalation exposures showed that the largest areas under the curves (AUC) s in both examinations occurred at 1 month after exposure.

Conclusion

These data suggest that MPO can be a useful biomarker for the ranking of the pulmonary toxicity of nanomaterials, especially at 1 month after exposure, in both intratracheal instillation and inhalation exposure.

     

Modified fuzzy gap statistic for estimating preferable number of clusters in fuzzy k-means clustering

In clustering methods, the estimation of the optimal number of clusters is significant for subsequent analysis. Without detailed biological information on the genes involved, the evaluation of the number of clusters becomes difficult, and we have to rely on an internal measure that is based on the distribution of the data of the clustering result. The Gap statistic has been proposed as a superior method for estimating the number of clusters in crisp clustering. In this study, we proposed a modified Fuzzy Gap statistic (MFGS) and applied it to fuzzy k-means clustering. For estimating the number of clusters, fuzzy k-means clustering with the MFGS was applied to two artificial data sets with noise and to two experimentally observed gene expression data sets. For the artificial data sets, compared with other internal measures, the MFGS showed a higher performance in terms of robustness against noise for estimating the optimal number of clusters. Moreover, it could be used to estimate the optimal number of clusters in experimental data sets. It was confirmed that the proposed MFGS is a useful method for estimating the number of clusters for microarray data sets.     

ALOS/PALSAR full polarimetric observations of the Iwate–Miyagi Nairiku earthquake of 2008

We analysed Advanced Land Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) data on the areas damaged by the Iwate–Miyagi Nairiku earthquake that struck Japan in 2008. The observations before and after the earthquake have been carried out in the full polarimetric mode. We observed the dominance of surface scattering of the three-component scattering model in the landslide areas and identified 11 of the 13 landslide areas. However, we also detected vacant pieces of land, pastures and other land bodies. The possible landslide areas are estimated for 102 patch areas, of which 36 correspond to the actual landslide areas. This method is useful to detect the landslide area when the land classification map or optical image taken before a disaster is available. We propose the use of σ⁰ _VH information to distinguish the landslide areas from the other areas. Since σ⁰ _VH is sensitive to the surface roughness of an area, vacant pieces of land and pastures, which have a relatively low surface roughness, can be distinguished from the landslide areas, which have a high surface roughness. By combining the surface scattering and the σ⁰ _VH filter, the number of possible landslide areas is reduced from 102 to 54, which include the actual landslide areas except for some small patch areas.     

Investigation of the arrangement of oxide ion vacancies and their effect on the crystal structure of BaFe0.9In0.1O3−δ

The crystal structure of BaFe_0.9In_0.1O_3−δ, which was prepared via heating in N₂ (BFI010-N₂), was evaluated using high-temperature X-ray diffraction (XRD) and in situ convergent-beam electron diffraction (CBED) at room temperature and 700°C. Although the crystal structure of BFI010-N₂ at room temperature was assigned to a cubic perovskite-type structure based on the XRD results, the CBED patterns indicated that the space group of its crystal structure was not (No. 221), which corresponds to an ideal cubic perovskite. When the temperature was increased to 700°C, the symmetries for the space group of cubic perovskite were directly observed by means of in situ CBED, indicating that the partial ordering and/or clustering of oxide ion vacancies in the BFI010-N₂ vanished and that the oxide ion vacancy arrangements became completely random. The change in crystal symmetry agreed with a sudden decrease in the activation energy of oxide ion conduction at 600°C. The crystal symmetry of the BaFe_0.9In_0.1O_3−δ sample that was prepared via heating in O₂ (BFI010-O₂) and had a decreased δ value was compared with that of the BFI010-N₂ sample. It was concluded that the same phase transition also occurred by a decrease in δ, similar to phase transitions caused by increasing the temperature.