Incretins including glucagon-like peptide-1 (GLP-1) and glucose‑dependent insulinotropic polypeptide (GIP) secreted from the small intestine after oral food ingestion are currently recognized to stimulate insulin secretion from pancreatic β cells. We previously reported that p70 S6 kinase limits the tumor necrosis factor‑α (TNF‑α)‑stimulated interleukin-6 (IL‑6) synthesis in osteoblast‑like MC3T3‑E1 cells. In the present study, we investigated the effects of incretins on the TNF‑α‑induced IL‑6 synthesis and the underlying mechanism in MC3T3‑E1 cells. GLP‑1 and GIP significantly upregulated both TNF‑α‑stimulated IL‑6 release and mRNA levels. Wedelolactone, an inhibitor of IκB kinase, amplified the TNF-α-induced IL‑6 release. GLP‑1 significantly attenuated the TNF‑α‑induced phosphorylation of IκB without affecting the phosphorylation of p70 S6 kinase. On the other hand, GLP‑1 markedly induced the phosphorylation of cAMP response element-binding protein (CREB). H‑89, an inhibitor of protein kinase A, significantly suppressed the enhancement by GLP-1 of TNF-α-stimulated IL‑6 release. Dibutyryl cAMP, a permeable analogue of cAMP, which suppressed the TNF-α-induced IκB phosphorylation, amplified the IL‑6 release. These results strongly suggest that incretins upregulate the TNF-α-stimulated IL‑6 synthesis in osteoblasts, and that the amplifying effect of incretin is exerted via reducing the IκB/NF‑κB pathway through the adenylyl cyclase-cAMP system.
Coherent space-time codes perform not so excellent in high moving speed case due to the inaccurate channel estimation. However, differential space-time code is appealing in this case because no channel estimation is needed. While in low and middle signal-to-noise ratio regions differential space-time codes are inferior to the coherent ones. To achieve an excellent performance in a various moving speed environments, we develop an adaptive transmission scheme in this paper where coherent space-time code is applied in low and middle moving speed cases, while differential space-time code is used in high moving speed case. Because the proposed scheme adopts the space-time codes wisely according to the moving speed, it outperforms the scheme which purely utilizes coherent space-time code or differential space-time code and thus is suitable for various moving speed environments. Moreover, two differential space-time codes based on differential Alamouti code are proposed in this paper with the merits of low decoding complexity, suitable for general number of transmit antennas and no code rate loss. The effectiveness of the proposed scheme and the proposed differential space-time codes is supported by numerical simulations.
This study investigated the important elements of emulated inertia control for grid-connected inverter-based power supply sources and identified the issues to be addressed for its integration into the electric power transmission and distribution system. For the first time, we categorized the emulated inertial control algorithms into five types based on three different aspects. Five emulated inertia control algorithms were simulated in order to compare their effectiveness in suppressing frequency fluctuations. In addition, a representative emulated inertia control algorithm based on the voltage-controlled method and another based on the current-controlled method were distinguished. The two emulated inertia control algorithms were implemented and demonstrated using the experimental hardware of a 5 [kVA] inverter-based power supply.
Aim Sex‐ and age‐related differences in mid‐thigh composition and muscle quality remain unclear. The present study aimed to clarify these differences using computed tomography in middle‐aged and elderly J apanese. Methods A total of 2310 participants (age 40–89 years), who were randomly selected from the local residents, underwent computed tomography examination of the right mid‐thigh. Thigh circumference and cross‐sectional areas of the thigh, muscle, quadriceps, non‐quadriceps, fat, and bone were measured. Knee extension strength and muscle quality index (knee extension strength/quadriceps cross‐sectional area) were also assessed. Sex‐ and age‐related differences in these indices were analyzed. Results The thigh cross‐sectional area in men and women decreased by 0.6% and 0.5%/year, respectively, because of a decrease in muscle cross‐sectional area (men 75.2%, women 40.6%), fat cross‐sectional area (men 24.4%, women 59.6%) and bone cross‐sectional area (men 0.5%, women −0.2%). Muscle cross‐sectional area in men and women decreased by 0.6% and 0.4%/year, respectively, because of a decrease in quadriceps cross‐sectional area (men 65.6%, women 81.6%) and non‐quadriceps cross‐sectional area (men 34.4%, women 18.4%). Muscle quality in men and women decreased by 0.4% and 0.3%/year, respectively. Conclusion Thigh cross‐sectional area decreased with age mainly because of a decrease in muscle cross‐sectional area in men and fat cross‐sectional area in women. The rate of decrease in muscle cross‐sectional area was 1.5‐fold higher in men than in women. Muscle cross‐sectional area decreased with age mainly because of a decrease in quadriceps cross‐sectional area, especially in women. Decrease in muscle quality with age was similar in both sexes. Geriatr Gerontol Int 2015; 15: 700–706.
