Projections of surface air temperature required to sustain permafrost and importance of adaptation to climate change in the Daisetsu Mountains, Japan.

Permafrost is known to occur in high mountainous areas such as the Daisetsu Mountains in Japan, which are located at the southernmost limit of the permafrost distribution in the world. In this study, areas with climatic conditions suitable for sustaining permafrost in the Daisetsu Mountains are projected using bias-corrected and downscaled climate model outputs and statistical relationships between surface air temperatures and permafrost areas. Using freezing and thawing indices, the size of the area in the Daisetsu Mountains where climatic conditions were suitable for permafrost were estimated to be approximately 150 km2 in 2010. Under the RCP8.5 scenario, this area is projected to decrease to about 30 km2 by 2050 and it is projected to disappear by around 2070. Under the RCP2.6 scenario, the area is projected to decrease to approximately 20 km2 by 2100. The degradation of mountain permafrost could potentially affect the stability of trekking trails due to slope displacement, and it may also have deleterious effects on current alpine ecosystems. It is therefore important to accurately monitor changes in the mountain ecosystem environment and to implement measures to adapt to an environment that is projected to change significantly in the future.

Microglia and astroglia prevent oxidative stress-induced neuronal cell death: implications for aceruloplasminemia.

We partially characterized the transferrin-independent iron uptake (Tf-IU) of neuronal and glial cells in the previous report. In the present study, we further examined a mechanism of which glial cells protect neuronal cells against iron stress using neuron-microglia (N-MG) and neuron-astrocyte (N-AS) co-cultures. When each solely purified cell was treated with iron citrate, cell death occurred in N and MG. However, AS proliferated under the same condition. Both N-MG and N-AS co-cultures were effective in resistance to excessive iron. The total and specific Tf-IU activities of N-MG co-cultures similar to those of N did not increase in a density-dependent manner. Contrarily, the total activity of AS was extremely high and the specific activity was extremely low as a result of proliferation. Regarding of effect of co-cultures on H(2)O(2)-induced cell death, N-MG co-cultures were less effective, but N-AS co-cultures were more effective in protecting N from the oxidative stress. These results suggest that N-MG co-cultures suppress the Tf-IU and N-AS co-cultures stimulate AS proliferation to protect neuronal cells. Brain cells from aceruloplasminemia with mutations in the ceruloplasmin gene take up iron by Tf-IU. Therefore, the different mechanisms of neuronal cell protection by MG and AS may explain the pathophysiological observations in the brains of patient with aceruloplasminemia.

Recognition of T cell epitopes unique to Cha o 2, the major allergen in Japanese cypress pollen, in allergic patients cross-reactive to Japanese cedar and Japanese cypress pollen.

BACKGROUND: Pollens from species of the Cupressaceae family are one of the most important causes of respiratory allergies worldwide. Many patients with pollinosis have specific IgE to both allergens from Japanese cedar and Japanese cypress pollen. We set out to identify T cell epitopes in Cha o 2, the second major allergen of Japanese cypress pollen. METHODS: T cell lines (TCL) and T cell clones (TCC) specific to Cha o 2 were generated from allergic patients cross-reactive to Japanese cedar and Japanese cypress pollen. T cell epitopes in Cha o 2 were identified by responses of TCL stimulated with overlapping peptides. Abilities of IL-4/IFN-gamma production by TCC were evaluated using enzyme immunoassay. RESULTS: Using TCL, 11 dominant and subdominant T cell epitopes were identified in Cha o 2. The subsets of TCC were predominantly of T helper 2-type. A T cell epitope p141-160 in Cha o 2 and corresponding peptide in Cry j 2 showed high homology. Although TCC PC.205.159 responded to stimulation with p141-160 in Cha o 2, it did not respond with corresponding peptide in Cry j 2, therefore, the T cell epitope was unique to Cha o 2. CONCLUSIONS: Eleven T cell epitopes that were identified are unique to Cha o 2. Cha o 2 is a putative aeroallergen that can potentially sensitize human T cells. We concluded that generation of T cells specific to Cha o 2 in allergic patients acts as one of the causes of continuous allergic symptoms in April.

Binaural perception of the modulation depth of AM signals.

The purpose of this study was to determine the binaurally perceived modulation depth (m) of the low rate amplitude modulated (AM) signals, under conditions of their dichotic presentation, i.e., when the AM signals presented to the left and the right ear had different modulation depths. The modulation depth was determined as a point of subjective equality between the sensations of the modulation depth of AM signals presented to the left and right ear, using a one-up, one-down adaptive procedure. Measurements were made for the carrier frequencies (f(c)) of 250, 1000, and 4000Hz, and the modulation frequency (f(m)) of 4Hz. Experimental data showed that, for sufficiently small interaural difference in modulation depth (Deltam), the perceived modulation approximated the mean of the modulation depths presented to the left and the right ear. However, for moderate and large Deltam, the binaurally perceived modulation was lower than the mean of m(l) and m(r) and the steepness of the function m=f(Deltam) gradually decreased with an increase of Deltam. Results of the calculation of the binaurally perceived modulation depth, obtained on the assumption of binaural loudness summation, were found to be consistent within the limit of standard deviation, with the experimental data for relatively wide range of Deltam.