Relationship between spatio-temporal characteristics of leaf-fall phenology and seasonal variations in near surface- and satellite-observed vegetation indices in a cool-temperate deciduous broad-leaved forest in Japan

We examined the relationship between the spatio-temporal distribution of leaf litter for each species and the seasonal patterns of in situ and satellite-observed daily vegetation indices in a cool-temperate deciduous broad-leaved forest. The timing and distribution of leaf-fall revealed spatio-temporal relationships with species and topography. Values of the normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), and green–red vegetation index (GRVI), measured both in situ and by satellite, and those of the in situ-measured leaf area index (LAI), rapidly declined at the peak of leaf-fall. At the late stage of leaf-fall, in situ-measured values of NDVI, EVI, and LAI declined but those of GRVI changed from decreasing to increasing. The peak timing of leaf-fall, when 50–73% of the leaf litter had fallen, corresponds to LAI = 1.80–0.81, NDVI = 0.61–0.54, EVI = 0.29–0.25, and GRVI = 0.01 ～ ?0.07. Although the distribution of leaf litter among species displayed spatial characteristics at the peak of leaf-fall, spatial heterogeneity of amount of leaf litter at the peak timing of leaf-fall was less than that at the beginning and end. These facts suggest that the criterion for determining the timing of leaf-fall from vegetation indices should be a value corresponding to the peak of leaf-fall rather than its end. In a high-biodiversity forest, such as this study forest, the effect of spatial heterogeneity on the timing and patterns of leaf-fall on vegetation indices can be reduced by observing only the seasonal variation in colour on the canopy surface by using GRVI, which consists of visible reflectance bands, rather than that of both leaf area and colour of the canopy surface by using NDVI and EVI, which consist of visible and near-infrared reflectance bands.     

Linearity and CNR Improvement Technologies against Optical Reflection in Fiber-Oriented Wireless Access Systems

It is important to consider optical reflectionconditions when designing fiber-oriented wirelessaccess systems around subcarrier optical transmissionsince the noise characteristic can be significantlydegraded by optical reflection, especially if narrowspectral width devices are used. The superluminescentdiode (SLD) offers stable noise and 3rd-orderintermodulation distortion (IM3) characteristics thatfollow the ideal cubic law, even under multipleoptical reflection. The SLD-predistorter combinationis proposed as a way to overcome the SLD's narrowdynamic range. It is experimentally found that thepredistorter reduces IM3 by 8 dB. The receiversensitivity of a practical system that uses theSLD-predistorter combination is discussed from theviewpoint of overall design. A superimposedsubcarrier modulation (SSM) technique is also proposedin order to reduce the reflection noise. Weexperimentally confirm that the SSM technique reducesthe noise degradation and provides stable opticaltransmission. An SSM design methodology is presentedthat takes both noise and linearity into account. TheSLD-predistorter and the SSM scheme make it possibleto realize stable transmission performance and widerdynamic range in the presence of optical reflection.     

Effect of hydrogen radical annealing on SiN passivated solar cells

Remote plasma was used for PE-CVD of SiN films and it was found that hydrogen radical (H^* ) annealing of c-Si cells with SiN films improved the efficiency of the cells. Cell efficiency of 21.8% was obtained by applying a SiN/SiO₂ double-layer structure on the emitter of a PERL-type solar cell. It was found that the H^* annealing has two effects: it reduces surface recombination velocity (SRV); and it degrades bulk-lifetime of p-type c-Si. To apply SiN practically, it is effective to use a rear n-floating or a triode structure. Reducing the exposed area of the p-type substrate by using n-type diffused layer increases the efficiency of solar cells.     

Design and Synthesis of Conformationally Constrained RORγt Inverse Agonists

Retinoic-acid-related orphan receptor γt (RORγt) inverse agonists could be used for the treatment of autoimmune diseases. Previously, we reported a novel quinazolinedione 1 a with a flexible linear linker as a novel RORγt inverse agonist. A U-shaped conformation in the complex structure of 1 a with RORγt protein was confirmed. Further improvement of the pharmacokinetic (PK) profiles was required because of the low drug exposure in mice upon oral administration (mouse AUC of 1 a : 27 ng ⋅ h ⋅ mL⁻¹ at 1 mg ⋅ kg⁻¹, p.o.). To improve the PK profiles, conformationally constrained U-shaped scaffolds were investigated. As a result, morpholine analogues with improved PK profiles and high potency were successfully identified. The substituent at the N1 position of the quinazoline moiety was also modified, leading to an enhancement of reporter activity. Consequently, compound 43 (N²-(3-chloro-4-cyanophenyl)-N⁴-(3-(cyclopropylmethyl)-1-isopropyl-2,4-dioxo-1,2,3,4-tetrahydroquinazolin-6-yl)morpholine-2,4-dicarboxamide) exhibited improved drug exposure (mouse AUC: 1289 ng ⋅ h ⋅ mL⁻¹ at 1 mg ⋅ kg⁻¹, p.o.). In addition, suppression of IL-17A gene expression by IL-23 stimulation in a mouse pharmacodynamics model was observed for 43 . The conformation of 43 with RORγt protein was also confirmed as U-shape by X-ray co-crystal structure analysis. The key interaction that boosts potency is also discussed.     

Synthesis and crystallographic study of Pb-Sr hydroxyapatite solid solutions by high temperature mixing method under hydrothermal conditions

The solid solutions in the system of Pb and Sr hydroxyapatite, Sr_10−xPb_xHAp (x = 0-10), were successfully synthesized by high-temperature mixing method (HTMM) at 160 °C for 12 h under hydrothermal conditions. The samples were characterized by X-ray diffraction, chemical analysis and electron microscopic observation, and the site of the metal ions in the solid solutions was analyzed with the Rietveld method. The lattice constants, both a and c, of the solid solutions varied linearly with Pb content. It was found that Pb ions in the solid solutions preferentially occupied the M(2) site in the apatite structure. HTMM gives Sr-Pb HAp solid solutions much better crystallization. However, due to the formation of intermediate compound of Pb₃O₂(OH)₂ in the Pb(NO₃)₂·4H₂O solution before mixing with (NH₄)₂HPO₄ solution at 160 °C, HTMM causes the decrease of crystallization of the samples with high Pb content.     

Time and temperature dependence of carbon/epoxy interface strength

Characterization of fiber/matrix interface is essential for the understanding of long-term properties of fiber reinforced composite materials. In this research, time and temperature dependence of carbon/epoxy interface strength were investigated. Unidirectional specimens were tested under tensile load up to failure, at various temperatures and testing speeds. The failure modes were identified as matrix dominant failure or interface dominant failure. A unit-cell model was considered to evaluate the stresses at the microscopic level and identify the critical points of highest stresses. Time and temperature dependent stress-concentration factor and thermal residual stress at the critical points were calculated using viscoelastic FEA. The micro stresses at the critical points were found to be properly represented by a bilinear curve with the interface dominant failure mode associated with the horizontal portion of the curve, suggesting that the interface strength is independent of time and temperature.     

Temporal and spatial expression of distinct troponin T genes in embryonic/larval tail striated muscle and adult body wall smooth muscle of ascidian

During development of the ascidian Halocynthia roretzi, the tadpole larva hatched from the tailbud embryo metamorphoses to the adult with a body wall muscle. Although the adult body wall muscle is morphologically nonsarcomeric smooth muscle, it contains a troponin complex consisting of three subunits (T, I, and C) as do vertebrate striated muscles. Different from vertebrate troponins, however, the smooth muscle troponin promotes actin-myosin interaction in the presence of high concentration of Ca2+, and this promoting property is attributable to troponin T. To address whether the embryonic/larval tail striated muscle and the adult smooth muscle utilize identical or different regulatory machinery, we cloned troponin T cDNAs from each cDNA library. The embryonic and the adult troponin Ts were encoded by distinct genes and shared only < 60% identity with each other. These isoforms were specifically expressed in the embryonic/larval tail striated muscle and the adult smooth muscle, respectively. These results may imply that these isoforms regulate actin-myosin interaction in different manners. The adult troponin T under forced expression in mouse fibroblasts was unexpectedly located in the nuclei. However, a truncated protein with a deletion including a cluster of basic amino acids colocalized with tropomyosin on actin filaments. Thus, complex formation with troponin I and C immediately after the synthesis is likely to be essential for the protein to properly localize on the thin filaments.     

Prevention of infections in a case with myelodysplastic syndrome by an intermittent subcutaneous administration of G-CSF

An 83-year-old male was admitted to our hospital because of pancytopenia and low grade fever on April 19, 1993. On admission, hematological data were as follows: WBC 1,000/microliters with 19% neutrophils, RBC 367 x 10(4)/microliters, Hb 9.5 g/dl and platelets 6.7 x 10(4)/microliters. Bone marrow examination revealed 6.6% myeloblasts and 33.5% erythroblasts. Morphological abnormalities included hypersegmentation, degranulation and pseudo-Pelger's nuclear anomaly in neutrophils. Based on these findings the diagnosis of refractory anemia with excess of blasts (RAEB) of the myelodysplastic syndrome (MDS) was made and therapy with low dose Cytarabine (Ara-C) was initiated in April 1993. The patient had two episodes of severe pneumonia in June and July. Therefore, 75 micrograms/day of G-CSF was given in addition to antibiotic therapy for the second episode of infection in July. Thereafter the severe infection subsided, and G-CSF administration was switched to an intermittent schedule (75 micrograms twice a week) since September. Cytarabine ocfosfate (100 mg/day) was added for 10-14 days at interval 1-2 months from October,1993. He has been well with no episode of infection for more than two year. One major concern regarding the clinical application of G-CSF in MDS patients is related to the possible stimulation of leukemic cell proliferation. Frequent hematological monitoring is necessary in patients with RAEB who are prone to develop acute myeloid leukemia. However, we administered G-CSF at a relatively low dose twice a week for over two year and could successfully prevent infections without inducing the leukemic changes.     

Iron nutrition and anaemia in a malaria-endemic environment: haematological investigation of the Gidra-speaking population in lowland Papua New Guinea

Blood examination was conducted for the four Gidra-speaking village groups in Papua New Guinea, who were characterized by high Fe intake and high malaria prevalence with marked inter-village differences. The northern riverine villagers, whose Fe intake was higher than the other three village groups, did not suffer from Fe-deficiency anaemia in their malaria-endemic environment; nor did the inland villagers, with their second highest Fe intake and their malaria-free environment, suffer from Fe-deficiency anaemia. However, several individuals of the southern riverine village suffered from anaemia in a malaria-endemic environment, although their Fe intake was almost the same as the inland villagers'. A considerable proportion of the coastal villagers were anaemic, reflecting the lowest Fe intake and the highest malaria prevalence. An inter-village comparison of the relationships between haemoglobin levels and transferrin saturation revealed that the southern riverine villagers needed smaller amounts of circulating Fe for erythropoiesis than the northern riverine and inland villagers, reflecting the long-term human-environment conditions such as the density of malaria vectors and the people's dietary habits. Fe supplementation was not judged effective against hypoferraemia and/or anaemia in such a population. As the incidence of malaria had no significant long-lasting effect on Fe stores or circulating Fe concentration, but did have an effect on anaemia, the hypothesis that malaria causes a transfer of Fe from the blood to parenchymal tissues as a defence against infectious diseases was not supported.