Microbial biomass in relation to primary succession on arctic deglaciated moraines

Microbial biomass in arctic soil was examined in relation to a primary succession on arctic deglaciated moraines in Ny-Alesund, Svalbard (79°N, 12°E). Soil samples at four study sites representing different successional stages were collected at every 1cm depth from the soil surface to 3cm depth in early August 1995. Microbial biomass was measured with a substrate-induced respiration procedure. The microbial biomass was highest at the soil surface (0-1cm depth) in all successional stages, and decreased to a negligible amount at 3cm depth. Mean microbial biomass in 0-2cm layer increased from 0.06mgCg^ soil d. w. in the youngest site to 1.03mgC g^ soil d. w. in the oldest site, which is comparable to ecosystems in warmer regions. Throughout all successional stages, there was positive high correlation between soil carbon or nitrogen content and microbial biomass

Soil respiration in a high arctic glacier foreland in Ny-Alesund, Svalbard

Soil respiration rates were measured in a successional glacier foreland in Ny-_lesund, Svalbard, and the amount of CO2 efflux during the plant-growing season was estimated using a simple regression model. Three study sites (Site 1, Site 2 and Site 3) were set up along with the primary succession in the deglaciated area of East Br_gger glacier in Ny-_lesund, Svalbard, Norway (79‹N 12‹E). Another study site, Site RB, was set up on a riverbed in the Bay River between Site 2 and Site 3. Soil respiration (SR), air temperature at 10 cm height (AT), soil surface temperature (SST) and soil temperature at 1 cm depth (ST) were measured at the four study sites with an open-airflow system using an infra-red gas analyzer from July to August, 1995. The mean soil respiration rate varied among the four sites: 6.2, 44, 63 and 3.7 mg CO2 m-2 h-1 at Site 1, Site 2, Site 3 and Site RB, respectively. These differences in the soil respiration rate among the four sites corresponded with the soil organic amount, microbial biomass, and root biomass. The soil respiration rate showed the best correlation with AT at Site 1, Site 2 and Site RB, and with ST at Site 3. The cumulative amount of CO2 efflux calculated using correlation equations obtained from the above relationships between SR and AT or ST was 5.8, 46, 69 and 3.3 g CO2 m-2 at Site 1, Site 2, Site 3 and Site RB, respectively, for two months (from July to August, 1995). These values were extremely low compared to those of warmer ecosystems, such as low-arctic tundra, temperate mixed forests, and tropical moist forests

Autophagy as a Therapeutic Target in Diabetic Nephropathy

Diabetic nephropathy is a serious complication of diabetes mellitus, and its prevalence has been increasing worldwide. Therefore, there is an urgent need to identify a new therapeutic target to prevent diabetic nephropathy. Autophagy is a major catabolic pathway involved in degrading and recycling macromolecules and damaged organelles to maintain intracellular homeostasis. The study of autophagy in mammalian systems is advancing rapidly and has revealed that it is involved in the pathogenesis of various metabolic or age-related diseases. The functional role of autophagy in the kidneys is also currently under intense investigation although, until recently, evidence showing the involvement of autophagy in the pathogenesis of diabetic nephropathy has been limited. We provide a systematic review of autophagy and discuss the therapeutic potential of autophagy in diabetic nephropathy to help future investigations in this field

E22Δ Mutation in Amyloid β-Protein Promotes β-Sheet Transformation, Radical Production, and Synaptotoxicity, But Not Neurotoxicity

Oligomers of 40- or 42-mer amyloid β-protein (Aβ40, Aβ42) cause cognitive decline and synaptic dysfunction in Alzheimer's disease. We proposed the importance of a turn at Glu22 and Asp23 of Aβ42 to induce its neurotoxicity through the formation of radicals. Recently, a novel deletion mutant at Glu22 (E22Δ) of Aβ42 was reported to accelerate oligomerization and synaptotoxicity. To investigate this mechanism, the effects of the E22Δ mutation in Aβ42 and Aβ40 on the transformation of β-sheets, radical production, and neurotoxicity were examined. Both mutants promoted β-sheet transformation and the formation of radicals, while their neurotoxicity was negative. In contrast, E22P-Aβ42 with a turn at Glu22 and Asp23 exhibited potent neurotoxicity along with the ability to form radicals and potent synaptotoxicity. These data suggest that conformational change in E22Δ-Aβ is similar to that in E22P-Aβ42 but not the same, since E22Δ-Aβ42 exhibited no cytotoxicity, unlike E22P-Aβ42 and wild-type Aβ42

Characterization of coronary calcified plaque by using multimodality intravascular imaging

Regular Articlejournal articl

High-pressure Raman study of the Ba-doped silicon clathrate Ba 24Si100 up to 27 GPa

High-pressure Raman scattering of type-III silicon clathrate Ba 24Si100 has been measured up to 27 GPa at room temperature. Low-frequency vibrational modes associated with Ba atoms inside three kinds of cages were found around 45-90 cm-1. The Si framework Raman bands were observed around 115-415 cm-1, which are altogether shifted toward lower frequencies as compared to those of type-I Ba 8Si46. High-pressure phase transition occurs at 6.5 GPa, which seems to be due to the structural distortion induced by the increasing guest(Ba)-host(Si) couplings. Ba24Si100 becomes irreversibly amorphous above 23 GPa. This pressure is lower than those of type-I Si clathrates, which suggests that type-III structure is less stable than type-I under high pressures

The Role of Autophagy in the Pathogenesis of Diabetic Nephropathy

Diabetic nephropathy is a leading cause of end-stage renal disease worldwide. The multipronged drug approach targeting blood pressure and serum levels of glucose, insulin, and lipids fails to fully prevent the onset and progression of diabetic nephropathy. Therefore, a new therapeutic target to combat diabetic nephropathy is required. Autophagy is a catabolic process that degrades damaged proteins and organelles in mammalian cells and plays a critical role in maintaining cellular homeostasis. The accumulation of proteins and organelles damaged by hyperglycemia and other diabetes-related metabolic changes is highly associated with the development of diabetic nephropathy. Recent studies have suggested that autophagy activity is altered in both podocytes and proximal tubular cells under diabetic conditions. Autophagy activity is regulated by both nutrient state and intracellular stresses. Under diabetic conditions, an altered nutritional state due to nutrient excess may interfere with the autophagic response stimulated by intracellular stresses, leading to exacerbation of organelle dysfunction and diabetic nephropathy. In this review, we discuss new findings showing the relationships between autophagy and diabetic nephropathy and suggest the therapeutic potential of autophagy in diabetic nephropathy

High-pressure Raman study of the iodine-doped silicon clathrate I8Si44I2

Raman scattering measurements of an iodine-doped I8Si44I2 clathrate have been performed at pressures up to 28 GPa and 296 K. We found two Raman peaks at 75 and 101 cm-1 associated with the vibrations of guest I atoms inside the host Si cages, and observed some framework vibrations around 120–500 cm-1. These characteristic Raman bands and their pressure dependence are investigated in consideration of our recent Ba8Si46 studies. The lowest-frequency framework vibration at 133 cm-1 shows the softening with pressure, which seems to be the common feature of Si clathrates. A strong and broad Raman band centered at 461 cm-1 is identified to the highest-frequency framework vibration, which is likely intensified and broadened by the considerable framework distortion due to the replacement of framework Si with larger I atom. No obvious pressure-induced phase transition was found up to 28 GPa. The guest-host interactions are investigated by the present vibrational properties and are compared with those of previous neutron studies of I8Si44I2

Cゲンゴ ショリケイ VERSION 2 ニツイテ

C is a general-purpose programming language which is suited to structured programming. It has the ability of system programming, as it is a relative low level language that lets users specify every detail in program logic to achieve maximum computer efficiency. The C language processor (Version 2) containning the compiler and the run time library routines is implemented on MELCOM COSMO model 700 III/800 III computers. As the recursive top down syntax analysis method and some local optimizing features are applied to construct the compiler, compact and efficient obiect programs can be generated. Its performance reaches the level of the optimized Fortran 77 processor on host machine. The large part of this compiler is coded in Pascal language to make maintenance easy