43 research outputs found
Adaptive data rate control TDMA systems as a rain attenuation compensation technique
Rainfall attenuation has a severe effect on signal strength and impairs communication links for future mobile and personal satellite communications using Ka-band and millimeter wave frequencies. As rain attenuation compensation techniques, several methods such as uplink power control, site diversity, and adaptive control of data rate or forward error correction have been proposed. In this paper, we propose a TDMA system that can compensate rain attenuation by adaptive control of transmission rates. To evaluate the performance of this TDMA terminal, we carried out three types of experiments: experiments using a Japanese CS-3 satellite with Ka-band transponders, in house IF loop-back experiments, and computer simulations. Experimental results show that this TDMA system has advantages over the conventional constant-rate TDMA systems, as resource sharing technique, in both bit error rate and total TDMA burst lengths required for transmitting given information
Growth and applications of GeSn-related group-IV semiconductor materials
We review the technology of Ge1āxSnx-related group-IV semiconductor materials for developing Si-based nanoelectronics. Ge1āxSnx-related materials provide novel engineering of the crystal growth, strain structure, and energy band alignment for realising various applications not only in electronics, but also in optoelectronics. We introduce our recent achievements in the crystal growth of Ge1āxSnx-related material thin films and the studies of the electronic properties of thin films, metals/Ge1āxSnx, and insulators/Ge1āxSnx interfaces. We also review recent studies related to the crystal growth, energy band engineering, and device applications of Ge1āxSnx-related materials, as well as the reported performances of electronic devices using Ge1āxSnx related materials
Genomeāwide SNP genotyping reveals hidden population structure of an acroporid species at a subtropical coral island: Implications for coral restoration
1. It is essential to consider genetic composition for both conventional coral restoration management and for initiating new interventions to counter the significant global decline in living corals. Population genetic structure at a fine spatial scale should be carefully evaluated before implementing strategies to achieve self-sustaining ecosystems via coral restoration.
2. This study investigated the population genetic structure of two acroporid species at Kume Island, Okinawa, Japan. There were 140 colonies of Acropora digitifera collected from seven study sites, and 81 colonies of Acropora tenuis from six sites. In total, 384 single nucleotide polymorphism (SNP) loci for A. digitifera and 470 SNPs for A. tenuis were obtained using a comparatively economical technique, Multiplexed ISSR Genotyping by sequencing.
3. Observed heterozygosity was significantly lower than expected heterozygosity at all SNP sites in both acroporid species, suggesting deficient genetic diversity possibly caused by past massive coral bleaching. Even though both species are broadcast spawners, the population structure was different in the two species. No detectable structure was evident in A. digitifera, but two distinct clades were found in A. tenuis. The genetic homogeneity of A. digitifera at Kume Island suggests that this species could be used as a focal species for active restoration in terms of genetic differentiation at this island. By contrast, A. tenuis unexpectedly included two distinct clades with little or no admixture within a small study area, possibly representing two reproductively isolated cryptic species. Thus, when using A. tenuis, it would be prudent to avoid disturbing the genetic composition of wild populations until this question is answered.journal articl
The degree of social difficulties experienced by cancer patients and their spouses
Abstract Background Although recent studies have increasingly reported physical and psychological problems associated with cancer and its treatment, social problems of cancer patients and their families have not been sufficiently elucidated. The present study aimed to identify cancer-associated social problems from the perspectives of both patients and their spouses and to compare and analyze differences in their problems. Methods This was a cross-sectional internet-based study. Subjects were 259 patients who developed cancer within the previous five years and 259 patientsā spouses; the data were derived from two surveys in 2010 (patients) and 2016 (spouses) whose participants were not part of the same dyad but matched by propensity scores, estimated for age, sex, and the presence or absence of recurrence. We investigated the social difficulties of cancer patients and patientsā spouses. Regarding social difficulties experienced by cancer patients and spouses, the 60 patient survey items were categorized into 14 labels by the Jiro Kawakita (KJ) method, which is a qualitative synthesis method developed by Kawakita to classify categorical data. Results Although patients had higher scores on most subcategories, young spouses aged 39 or younger and female spouses had difficulty scores as high as the corresponding patients on many subcategories. Conclusion Health care providers should show sufficient concern for both patients and their spouses, particularly young and female spouses
Implication of IZUMO2 in the cellāinācell phenomenon: A potential therapeutic target for tripleānegative breast cancer
Abstract Background Tripleānegative breast cancer (TNBC) is characterized by the loss of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. The aggressive clinicopathological features and resistance to currently available therapeutics of the disease warrant an urgent need for the development of novel alternate therapeutic options. We have previously reported adiponectināexpressing regulatory T cells (AāTregs), which can induce apoptosis in TNBC through the cellāinācell phenomenon. In this study, we aimed to elucidate the molecule that allows TNBC cells to engulf AāTregs. Methods A monoclonal antibody, which repressed the engulfment of AāTregs by TNBC cells, was developed. Immunoprecipitation followed by mass spectrometry and small interfering RNAsāmediated gene silencing was performed to characterize the antigen. Results We successfully generated a monoclonal antibody, designated G1D7, which abrogated the engulfment of AāTregs by TNBC and subsequent AāTregāmediated apoptosis. G1D7 detected the immunoglobulinālike type I membrane protein IZUMO2, a molecule related to IZUMO1 that is essential for cellācell membrane binding and fusion of sperm to oocyte. Conclusion The findings highlight the importance of IZUMO2 on TNBC cells in facilitating the cellāinācell phenomenon by AāTregs