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排序方式: 共有309条查询结果,搜索用时 15 毫秒
91.
Jun’ichiro Ide Tomonori Kume Yoshifumi Wakiyama Naoko Higashi Masaaki Chiwa Kyoichi Otsuki 《Forest Ecology and Management》2009
Japanese cypress (Chamaecyparis obtusa) is one of the most common plantation species in Japan. In most Japanese cypress plantations, closure of the forest canopy hinders understory growth because of insufficient management practices. Thus leaf litter barely covers the soil surface. Such plantations are vulnerable to surface erosion triggered by rainfalls, and could yield large amounts of suspended sediment (SS). However, few studies have investigated the annual SS yield. This study aimed to develop a modified model of SS yields, and to accurately estimate and characterize the annual SS yield from a Japanese cypress plantation. For this, hydrological surveys were conducted for 5 years, and stream water was sampled weekly as well as sequentially at 15–60 min intervals in each of 14 rain events in a small forested watershed of Japanese cypress. The root mean square error (RMSE) and the annual SS yield estimates were obtained using three different equations: the rating curve derived from instantaneous SS concentration versus stream discharge relationship (SSC − Q equation); the rating curve derived from cumulative SS yield versus cumulative specific discharge relationship (∑SS − ∑Q equation); and the multiple regression of cumulative SS yield expressed as functions of cumulative specific discharge and antecedent rainfalls (∑SS − ∑Q × AR equation). The ∑SS − ∑Q × AR equation is a modified model considering the effects of antecedent rain history on the SS yield. The parameters in each equation were determined by a nonlinear least square method. Of the three equations, the RMSE was the highest using the SSC − Q equation. Although the ∑SS − ∑Q equation and the ∑SS − ∑Q × AR equation gave similar RMSE values, the SS yields extrapolated by the ∑SS − ∑Q equation would be overestimated. Thus, the 5-year average of annual SS yield estimated by the ∑SS − ∑Q equation was three times larger than that estimated by the ∑SS − ∑Q × AR equation. These results indicate that the ∑SS − ∑Q × AR equation more accurately estimates the annual SS yield, compared with the other two equations. The results also suggest that antecedent rain history, as well as stream discharge, should be considered for appropriately estimating the annual SS yield. The annual SS yield estimated by the ∑SS − ∑Q × AR equation was the largest among 25 undisturbed forested watersheds, except for two watersheds dominated by sandstone. Our results suggest that the annual SS yield is greater from a Japanese cypress plantation under current management practices than from other undisturbed forests. 相似文献
92.
Asaki ABE Kazumasa OHTSUKI Yoshiki SUZUKI Takiko TAKAHASHI Yasuhiro KONDO 《Animal Science Journal》2002,73(4):309-311
The characteristics of the contraction of vascular smooth muscle were examined in thoracic aorta and ischiadic artery of chickens aged 3, 6, 10 and 18 weeks. High K+ solution induced a sustained contraction in smooth muscle preparations of aorta and ischiadic artery in vitro . The contraction of the ischiadic artery became greater with age, whereas the contraction of the aortic preparation did not. In the ischiadic artery, the magnitude of the contraction divided by the weight of the muscle preparation was constant at all ages studied. However, those in the aortic preparation decreased with age. These results suggest that the changes in the contractile responses of vascular smooth muscle owing to the age of chickens vary widely according to the preparations of blood vessels, and that the functional smooth muscle cells in the thoracic aorta of chicken do not increase with age. 相似文献
93.
ABSTRACT: Shell growth and age determination of Corbicula japonica were investigated from samples collected monthly at two sites and field growth experiments from November 1999 to November 2000 in Lake Shinji. Both specimens did not grow in winter when the water temperature was below 11°C, but grew rapidly from spring to early summer when the water temperature rose from 15°C to 30°C, before further growing slowly from summer to autumn after the main breeding period. The monthly marginal growth distribution of the samples indicated that the concentric groove on the shell surface was an annual growth ring. It is concluded that the age of C . japonica in the i -ring group when the shell growth resumed in spring was i + 0.5 ( i = 1, 2, · · ·), because the first true growth ring was formed at 0–2 mm in shell length, which then faded with growth. Lee's phenomenon was observed in the age determination results, and thus the growth coefficient and the asymptotic shell length of the von Bertalanffy growth equation were not estimated from the samples. However, these parameters were estimated from the annual shell length increments of the experimental individuals, which were 0.331/year and 28.2 mm, respectively. 相似文献
94.
Koichiro GAMOH Mari NAKAMIZO Masatoshi OKAMATSU Yoshihiro SAKODA Hiroshi KIDA Shoko SUZUKI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(1):139-142
H5 highly pathogenic avian influenza (HPAI) viruses have spread worldwide, and
antigenic variants of different clades have been selected. In this study, the national
stockpiled vaccine prepared from A/duck/Hokkaido/Vac-1/2004 (H5N1) strain was evaluated
for the protective efficacy against H5N8 HPAI virus isolated in Kumamoto prefecture,
Japan, in April 2014. In the challenge test, all of the vaccinated chickens survived
without showing any clinical signs and reduced virus shedding. It was concluded that the
present stockpiled vaccine was effective against the H5N8 HPAI virus. 相似文献
95.
96.
Kei IMURA James Kenn CHAMBERS Kazuyuki UCHIDA Shunsuke NOMURA Satoshi SUZUKI Hiroyuki NAKAYAMA Yasutsugu MIWA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(12):1667-1670
An 8-month-old common marmoset
(Callithrix jacchus) was presented with tic-like symptoms, and a
2-year-old pigmy marmoset (Callithrix pygmaea) was presented with dyspnea
and hypersalivation. Both monkeys died within a few days, and necropsies were performed.
Histopathological examinations revealed ulcerative stomatitis with epithelial cell
swelling and eosinophilic intranuclear inclusion bodies in the oral epithelium of both
cases. In the central and peripheral nervous systems, neuronal cell degeneration with
intranuclear inclusion bodies was observed. Immunohistochemical examination using
anti-herpes simplex virus type 1 antibody revealed virus antigens in both cases. Both
animals had been kept as pets with limited exposure to the ambient environment except via
their owners. Therefore, herpes simplex virus type-1 was probably acquired from close
contact with their owners. 相似文献
97.
98.
Fika Yuliza PURBA Naoki SUZUKI Naoki ISOBE 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(2):338
The occurrence of multiple metabolic and inflammatory diseases in dairy cows is higher during the periparturient period, which may be triggered by bacterial components, but not a viable bacterium. This study aimed to determine the association of endometritis and ovarian follicular cyst (OFC) with mastitis in dairy cows. Ninety-eight Holstein dairy cows were clinically examined for endometritis and OFC approximately 30–50 days after calving. Blood and milk samples were collected for the determination of milk somatic cell count (SCC); milk interleukin-1β (IL-1β), tumor necrosis factor-α (TNFα), and interleukin-8 (IL-8) concentrations; and plasma haptoglobin (Hp) and lipopolysaccharide-binding protein (LBP) concentrations. Of the 98 dairy cows included in this study, 12 were diagnosed with endometritis and 37 cows were identified as OFC-positive, whereas the remaining 49 cows were healthy (without endometritis or OFC). The average and maximum SCCs and plasma Hp and LBP concentrations were not significantly different between the healthy cows and those with endometritis or OFC. However, when the maximum SCC was classified as <300, 300–1,000, or >1,000 × 103 cells/ml, the percentage of cows with the maximum SCC <300 × 103 cells/ml was significantly lower in the endometritis and OFC-positive groups than in the healthy group. These results suggested that cows with endometritis and OFC during the postpartum period exhibit high SCC, indicating that some bacterial components can be transferred between organs. 相似文献
99.
Maho NAKAZAWA Hirotaka TOMIYASU Kanako SUZUKI Hajime ASADA Aki FUJIWARA-IGARASHI Yuko GOTO-KOSHINO Aki OHMI Koichi OHNO Michio FUJITA Hajime TSUJIMOTO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(3):456
Nasal lymphoma (NL) is the most common nasal tumor in cats, and radiotherapy, chemotherapy, or a combination of these treatments have been described as the treatment for this disease. However, the previous studies included various machines and protocols of radiotherapy. Therefore, we aimed to retrospectively compare the prognosis among cases treated with palliative hypofractionated radiotherapy, chemotherapy, and a combination of them with united machine and protocol of radiotherapy. When compared overall survival and progression free survival, there was no significant difference among these three groups. The data of this study suggested that similar efficacy could be achieved by palliative hypofractionated radiotherapy, chemotherapy, or a combination of them. 相似文献
100.
Marina OTSUKA Mieko SUGIYAMA Takaaki ITO Kenji TSUKANO Shin OIKAWA Kazuyuki SUZUKI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(2):329
This study established the precision and accuracy of a modified latex agglutination turbidimetric immunoassay (LATIA) reagent, and evaluated the ability of the measurement of serum amyloid A (SAA) compared to haptoglobin and α1-acid glycoprotein, which are acute phase proteins (APPs), for diagnosis of clinical mastitis. Concentrations of APPs in cows with mastitis were significantly higher than those in healthy cow. Only the plasma SAA concentration in cows with clinical mastitis (44.90 mg/l; n=15) was significantly higher than that in those with subclinical mastitis (10.70 mg/l; n=16), enabling their diagnosis in contrast to other APPs. Thus, the SAA assay using a LATIA reagent is useful in assessing mastitis severity due to its higher sensitivity and specificity than other APP assays. 相似文献