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61.
Hagiwara T Wang H Suzuki T Takai R 《Journal of agricultural and food chemistry》2002,50(11):3085-3089
Fractal analysis of the morphology of ice crystal particles in frozen food was attempted for frozen soybean curd (tofu). From a microscopic image analysis of the ice crystal particles, it was found that the perimeter of the ice crystal particles could be recognized as a fractal. Effects of the storage time and storage temperature on the fractal dimension (d(p)) of the perimeter of the ice crystal particles were also investigated. As storage time was increased, the d(p) value tended to decrease. When the storage temperature was increased, the value of d(p) decreased more rapidly. The changes corresponded to the visual observation of the shape change for the ice crystal particles during storage reported by many researchers, suggesting that the fractal dimension d(p) could be used as a quantitative indicator reflecting the surface roughness of ice crystal particles. 相似文献
62.
Effects of agricultural land-use change and forest fire on N2 O emission from tropical peatlands, Central Kalimantan, Indonesia 总被引:1,自引:0,他引:1
63.
Tomoaki Morishita Ryusuke Hatano Osamu Nagata Kohei Sakai Takahiro Koide Osamu Nakahara 《Soil Science and Plant Nutrition》2013,59(8):1187-1194
Abstract It has been well documented by short-term artificial experiments that the CH4 uptake is inhibited by N input, especially NH4 p+-N input. To investigate the effect of the natural N input by throughfall and other factors on the CH4 uptake in forest soils, we measured the CH4 uptake rates for 6 months during the snow-free period of the year and N input by throughfall throughout the year at 10 sites in Hokkaido, Japan, from 1997 to 2002. Water filled pore space (WFPS) and pH values in the soils varied widely among the sites (38-93% and 3.9-6.2, respectively). The rates of NH4 p+-N and NH3 p--N inputs ranged from 1.3 to 6.9 kg N hap-1 yearp-1 and from 0.8 to 2.9 kg N hap-1 yearp-1, respectively. The NH4 p+-N input was generally higher than the NH3 p--N input. Total N input by throughfall amounted to 2.3-9.4 kg N hap-1 yearp-1. The highest CH4 uptake rate occurred within the period from July to September (41-215 μg CH4 mp-2 hp-1) each year at most sites. CH4 uptake rate was relatively low (~50 μg CH4 M-2 hp-1) at northern sites, while a high CH4 uptake rate was observed throughout the year 100 (? CH4 mp-2 hp-1) at southern sites. The mean CH4 uptake rates were significantly different among the sites. Cumulative CH4 uptake ranged from 1.4 to 6.6 kg CH4 hap-1 [184 d]p-1 with a mean values of 3.22 ± 1.36 kg CH4 hap-1 [184 d]p-1. Cumulative CH4 uptake increased with increasing temperature and decreased with an increase in precipitation (Rain), NH4 p+-N input (TFNH4) WFPS, soil total C (TC), and total N (TN). There was a quadratic relationship between the CH4 uptake and NH3 p--N input (TFNO3), soil pH, and C / N ratio in soil. A regression equation was obtained as follows to predict the CH4 uptake in forest soils: Cumulative CH4 uptake = 0.47 / Rain + 0.38 / TFNH4 + 0.34 / TC - 0.30 / TFN03 (R p2 = 0.74, p = 0.0001). This equation indicates that atmospheric N input into forest soils is one of the main factors that control cumulative CH4 uptake with precipitation, total carbon content in soil in Hokkaido, Japan. 相似文献
64.
Tomoaki Morishita Kyotaro Noguchi Yongwon Kim Yojiro Matsuura 《Soil Science and Plant Nutrition》2013,59(1):98-105
AbstractForest fires can change the greenhouse gase (GHG) flux of borea forest soils. We measured carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes with different burn histories in black spruce (Picea mariana) stands in interior Alaska. The control forest (CF) burned in 1920; partially burned (PB) in 1999; and severely burned (SB1 and SB2) in 2004. The thickness of the organic layer was 22 ± 6 cm at CF, 28 ± 10 cm at PB, 12 ± 6 cm at SB1 and 4 ± 2 cm at SB2. The mean soil temperature during CO2 flux measurement was 8.9 ± 3.1, 6.4 ± 2.1, 5.9 ± 3.4 and 5.0 ± 2.4°C at SB2, SB1, PB and CF, respectively, and differed significantly among the sites (P < 0.01). The mean CO2 flux was highest at PB (128 ± 85 mg CO2-C m?2 h?1) and lowest at SB1 (47 ± 19 mg CO2-C m?2 h?1) (P < 0.01), and within each site it was positively correlated with soil temperature (P < 0.01). The CO2 flux at SB2 was lower than that at CF when the soil temperature was high. We attributed the low CO2 flux at SB1 and SB2 to low root respiration and organic matter decomposition rates due to the 2004 fire. The CH4 uptake rate was highest at SB1 [–91 ± 21 μg CH4-C m?2 h?1] (P < 0.01) and positively correlated with soil temperature (P < 0.01) but not soil moisture. The CH4 uptake rate increased with increasing soil temperature because methanotroph activity increased. The N2O flux was highest [3.6 ± 4.7 μg N2O-N m?2 h?1] at PB (P < 0.01). Our findings suggest that the soil temperature and moisture are important factors of GHG dynamics in forest soils with different fire history. 相似文献
65.
This paper reports on an empirical investigation about regional economic impacts by the promotion of wood chip utilization in Maniwa city, Japan. We clarify the estimated potential of regional economy development by using input–output analysis for Maniwa city. The result indicates that 315 million JPY of woody chip products can be estimated to generate roughly 448 million JPY of direct, indirect, and induced economic effects. The value of 448 million JPY was equivalent to about 0.2 % of total production value in Maniwa. It is also expected to create approximately 21 jobs by promotion of wood chip utilization. We examined the regional economic impacts on the woody biomass utilization, and evaluated to estimate direct, indirect and induced economic effects, and job creation to clarify the economic impact on Maniwa. We will leave the negative economic effects and the environmental impacts in the process of woody biomass utilization as a future task. 相似文献
66.
Tomoaki Tochitani Izumi Matsumoto Kohei Hoshino Kaoru Toyosawa Mami Kouchi Takatoshi Koujitani Juki Kimura Hitoshi Funabashi 《Journal of toxicologic pathology》2013,26(2):187-191
The common marmoset (Callithrix
jacchus) is now widely used in various
research fields, including toxicology. However,
information about the background pathology of this
species is scarce. Here, we report a case of
rhabdomyosarcoma that spontaneously occurred in a
common marmoset. A 44-month-old male common
marmoset was euthanized due to bilateral hind limb
paralysis. At necropsy, a 2×2×5-cm intramuscular
mass was observed in the lower right back.
Histologically, the mass was mainly composed of
interlacing bundles of spindle-shaped tumor cells.
Immunohistochemically, the tumor cells were
positive for myogenin, desmin, vimentin and
alpha-smooth muscle actin. Ultrastructurally, the
tumor cells contained bundles of myofilaments with
Z-band-like structures. Thus, the tumor was
diagnosed as a rhabdomyosarcoma. To our knowledge,
this is the first report of spontaneous
rhabdomyosarcoma that was definitely diagnosed in
the common marmoset. 相似文献
67.
Remote sensing offers the potential to spatially map forest cover quickly and reliably for inventory purposes. We developed a new image analysis approach using an integrated methodology of “object-based” image classification techniques and field-based measurements to quantify forest cover in a degraded dry forest ecosystem on the leeward side of the Island of Hawaii. This new approach explicitly recognized the transitional areas between tree crowns and tree shades (tree shadows) as a unique class and fully utilized them for the quantification of canopy cover. Object-oriented classification of Ikonos-2 satellite images allowed delineation of tree shades and crowns and the transitional areas between them from objects with similar reflectance and size that were surrounding the trees. These included patches of fountain (Pennisetum setaceum) and kikuyu (Pennisetum clandestinum) grass, lava outcrops and lava–grass mixtures. Crown-shade transitions were clearly differentiated in spite of their wide range of spectral values and reflectance similarities with areas of lava–grass mixture. Segments representing tree shades and dark lava outcrops were also classified into their respective classes even if they were contiguous. The image estimates of canopy cover using the tree shade plus transition classes were linearly related with field estimates of canopy cover (R2 = 0.86 and slope = 0.976). Based on this relationship, dry forest cover throughout the 2627-ha area was estimated at 7.7 ± 1.9%. An immediate application of this new approach is to select and delineate areas with higher canopy cover in order to concentrate ecological restoration and conservation efforts. 相似文献
68.
69.
70.
Tanaka Kenzo Tomoaki Ichie Daisuke Hattori Joseph Jawa Kendawang Katsutoshi Sakurai Ikuo Ninomiya 《Forest Ecology and Management》2010
Uncertainties in the rate of biomass variation with forest ageing in tropical secondary forests, particularly in belowground components, limit the accuracy of carbon pool estimates in tropical regions. We monitored changes in above- and belowground biomass, leaf area index (LAI), and biomass allocation to the leaf component to determine the variation in carbon accumulation rate with forest age after shifting cultivation in Sarawak, Malaysia. Nine plots in a 4-year-old forest and fourteen plots in a 10-year-old forest were monitored for 5 and 7 years, respectively. Forest and plant part biomass were calculated from an allometric equation obtained from the same forest stands. Both above- and belowground biomass increased rapidly during the initial decade after abandonment. In contrast, a much slower rate of biomass accumulation was observed after the initial decade. LAI also increased by approximately double from the 4-year-old to 10-year-old forest, and then gently increased to the 17-year-old forest. We also found that allocation variation in leaf biomass and nitrogen was closely related to the rate of biomass accumulation as a forest aged. During the first decade after abandonment, a high biomass and nitrogen allocation to the leaf component may have allowed for a high rate of biomass accumulation. However, reduction in those allocations to leaf component after the initial decade may have helped to suppress the biomass accumulation rate in older secondary forests. Roots accounted for 14.0–16.1% of total biomass in the 4–17-year-old abandoned secondary forests. We also verified the model predicted values for belowground biomass by Cairns et al. (1997) and Mokany et al. (2006), although both models overestimated the values throughout our data sets by 45–50% in the 10-year-old forest. The low root:shoot ratio in the secondary forests may have caused this overestimation. Therefore, our results suggest that we should modify the models to estimate belowground biomass considering the low root:shoot ratio in tropical secondary forests. 相似文献