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61.
Takuo Nagaike 《Journal of Forest Research》2010,15(1):65-70
Species composition and community structure of naturally regenerated trees in Larix kaempferi plantations and natural forests were compared in relation to altitudinal gradient. Fifty-nine L. kaempferi plantations and 26 natural forest stands including old-growth and secondary forests were selected from 1300 to 2000 m a.s.l.
in Mt Kushigata of central Japan. Vegetation plots (10 × 10 m) were established in each stand (85 plots in total). Species
composition differed significantly between forest types, particularly on high altitude plots. Some species were significantly
biased to natural forests, while no species were biased to plantations. Although some species that responded significantly
to altitude were common to both forest types (e.g., Acer ukurunduese, Castanea crenata, and Fraxinus lanuginose f. serrata), some differed between forest types (e.g., Fagus japonica, Prunus maximowiczii, and P. nipponica). Thus, plantation management altered species responses to altitude. Altitude should be considered when planning and carrying
out forest ecological restoration in plantations, because species composition of naturally regenerated trees has already been
changed by past plantation management. In particular, attention should be paid to ecological restoration at high altitude. 相似文献
62.
Akira Itoh Tatsuhiro Ohkubo Satoshi Nanami Sylvester Tan Takuo Yamakura 《Forest Ecology and Management》2010
Habitat difference is an important mechanism for maintenance of tree diversity in tropical forests. The first step in studies of habitat difference is to statistically analyze whether the spatial distributions of tree populations are skewed to species-specific habitats; this is called a habitat association test. We propose a novel habitat association test on the basis of the probability of tree occurrence along a continuous habitat variable. The test uses torus shift simulations to obtain a statistical significance level. We applied this test to 55 common dipterocarp species in a 52-ha plot of a Bornean forest to assess habitat associations along an elevation gradient. The results were compared to those of three existing habitat association tests using the same torus shift simulations. The results were considerably different from one another. In particular, the results of two existing tests using discrete habitat variables varied with differences in habitat definitions, specifically, differences in elevation break points, and the number of habitat classes. Thus, definitions of habitats must be taken into account when habitat association tests with discrete habitat variables are used. Analyses of artificial populations independent of habitat showed that all of the tests used were robust with respect to spatial autocorrelation in tree distributions, although one existing test had a higher risk of Type I errors, probably due to the use of multiple tests of significance. Power analysis of artificial populations in which distributions were skewed to certain elevations showed that the novel test had comparable statistical power to the most powerful existing test. Statistical power was affected not by the total number of a given tree but by the number of clumps in a plot, suggesting that >5 clumps were required for a reliable result. 相似文献
63.
64.
Hiroo Madarame Ryuuji Harada Shinpei Kawarai Haruo Takeda Takuo Shida 《Journal of toxicologic pathology》2015,28(4):229-232
In this report, we describe a case of lipomatosis in the left parotid gland of an eight-year-old female Shetland sheepdog and review the relevant literature. Preoperative diagnosis of lipomatosis with Tru-Cut biopsy presented difficulties in this case. The postoperative diagnosis was based on the gross appearance of a non-infiltrative, circumscribed swollen mass in the parotid gland and the histological appearance of normal adipocytes that infiltrated into the parotid gland without involving surrounding structures. Additionally, flotation of the whole parotid gland in formalin solution together with well-maintained residual lobulation and a well-maintained configuration on the cut surface were identified as subsidiary characteristics of lipomatosis of the parotid gland. Lipomatosis of the parotid gland has been rarely reported in dogs and is a poorly understood condition. 相似文献
65.
A NOVEL SUPPORT DEVICE FOR HEAD IMMOBILIZATION DURING RADIATION THERAPY THAT IS APPLICABLE TO BOTH CATS AND DOGS 
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下载免费PDF全文 Yuki Nemoto Takuya Maruo Yasuhiro Fukuyama Shinpei Kawarai Takuo Shida Tomohiro Nakayama 《Veterinary radiology & ultrasound》2015,56(6):680-686
Repeatable head immobilization is important for minimizing positioning error during radiation therapy for veterinary patients with head neoplasms. The purpose of this retrospective cross‐sectional study was to describe a novel technique for head immobilization (Device II) and compare this technique with a previously described technique (Device I). Device II provided additional support by incorporating three teeth (vs. two teeth with Device I). Between 2011 and 2013, both devices were applied in clinically affected cats (Device I, n = 17; Device II, n = 11) and dogs (Device I, n = 85; Device II, n = 22) of various breeds and sizes. The following data were recorded for each included patient: variability in the angle of the skull (roll, yaw, and pitch), coordinates of the isocenter, and distance from the reference mark to the tumor. Devices I and II differed for skull angle variability during the treatment of dogs (roll, P = 0.0007; yaw, P = 0.0018; pitch, P = 0.0384) and for yaw of during the treatment of cats (P < 0.0001). In each case, Device II was superior to Device I. The distance from the reference mark to the center of the tumor was significantly decreased for Device II vs. Device I (dogs, P < 0.0001; cats, P = 0.0002). Device II also provided more accurate coordinates for the isocenter. Authors recommend the use of, Device II for future clinical patients. 相似文献
66.
In order to clarify the effects of both the social and natural environment on the changes in landscape structure we analyzed
landscape elements using aerial photographs taken in different years in the primary and coppice forests in theFagus crenata forest region of central Japan. The present landscape diversity calculated by Shannon's diversity index (H′) appeared to be higher than that observed in photographs from the earlier year. The site with no residential areas and dominated
by primary forests had a lower level of landscape diversity than the site which included some residential areas and coppice
forests. These results show that the intensity of human activities contributes to changes in landscape diversity. The landscape
diversity on private land was higher than that in the national forest, and the changes in landscape structure in the national
forest were different from those seen on private land. This suggests that land ownership significantly affects the changes
in landscape structure. Topographic factors also affect the changes in landscape structure. Consequently, not only the natural
environment (topography), but also the social environment (intensity of human activity and land ownership) strongly influence
the changes in landscape structure. 相似文献
67.
Kriangsak?Sri-ngernyuangEmail author Kwanchai?Chai-Udom Mamoru?Kanzaki Tatsuhiro?Ohkubo Takuo?Yamakura 《Journal of Forest Research》2003,8(4):311-316
The survival and germination traits of two tropical species of Lauraceae, Lindera metcalfiana and Litsea cubeba, were investigated in a 2-year burial experiment and subsequent germination tests of sequentially excavated seeds. Fresh seeds extracted from fruit were packed in aluminum mesh bags and buried 5cm deep in a mature montane forest in northern Thailand (1700m altitude). No seed mortality was recorded for Litsea, but Lindera experienced 26%–48% mortality after being buried for 122 days. These seeds did not germinate in the forest soil during the 2-year experimental period. We found that fresh seeds of these two species did not germinate even under open conditions, suggesting that the seeds are initially deeply dormant after dispersal. In contrast, 29%–60% of excavated Lindera seeds germinated under open conditions after being buried for 30–753 days, and excavated Litsea seeds began to germinate after being buried for 408 days. These findings suggest that seeds enter a state of enforced dormancy. The ratio of germinable seeds peaked 184 days after burial in Lindera (33%) and 930 days after burial in Litsea (91%). The longer period of deep dormancy in Litsea prior to enforced dormancy is concordant with the fact that for regeneration Litsea requires larger-scale disturbance than Lindera. 相似文献
68.
Ohnishi M Sawada T Hirose K Sato R Hayashimoto M Hata E Yonezawa C Kato H 《Veterinary microbiology》2011,154(1-2):202-207
The presence of metallo-β-lactamase (MBL)-producing and multidrug-resistant Pseudomonas aeruginosa (MDRP) strains among bovine isolates of Gram-negative bacilli, and O-serotypes of bovine Serratia marcescens and P. aeruginosa isolates have been reported rarely. The aims of this study were to (1) elucidate antimicrobial susceptibilities and O-serotypes of P. aeruginosa and S. marcescens isolates from bovine mastitis and the presence of MBL-producers and MDRP strains among them and (2) evaluate their relationships to human isolates. We investigated the MICs of 24 antimicrobials and O-serotypes for 116 P. aeruginosa and 55 S. marcescens isolates in Japan, primarily in 2006. A total of 171 isolates exhibited high antimicrobial susceptibilities with the exception of a partial drug. P. aeruginosa isolates exhibited high susceptibilities of ≥ 95.7% to ciprofloxacin, imipenem, meropenem, piperacillin, ceftazidime, cefepime, cefoperazone/sulbactam, amikacin, tobramycin, and gentamicin; however, they exhibited a susceptibility of only 69.8% to aztreonam. They exhibited substantial resistances to ceftriaxone, enrofloxacin, cefotaxime, and moxalactam. S. marcescens isolates exhibited high susceptibilities of ≥ 90.9% to kanamycin, ceftiofur, sulfamethoxazole-trimethoprim, and the 15 aforementioned drugs, but exhibited resistance to minocycline. Neither MBL-producers nor MDRP strains were detected among the 171 strains. The dominant serotypes of P. aeruginosa isolates were OG, OA, OB, OI, OF, OE, and OK; those of S. marcescens isolates were O6 and O5. Every S. marcescens isolate was pigmented. These findings suggest that bovine P. aeruginosa and S. marcescens isolates differ from human isolates from both antibiogram and phenotypic perspectives, and could help to evaluate differences in bacteriological characteristics between bovine and human isolates. 相似文献
69.
Kazuki Harada Masatake Muramatsu Shoko Suzuki Takuo Sawada Toshio Takahashi 《Research in veterinary science》2011,90(1):20-22
The pathogenicity of Erysipelothrix tonsillarum was evaluated in pigs immunosuppressed with cyclophosphamide (CY) or dexamethasone (DM). Animals were treated with 15 mg/kg CY (n = 8, five injections), 1 mg/kg DM (n = 8, nine injections) or left untreated (n = 8). On the fifth day after the beginning of drug treatments, swine were inoculated with one of two E. tonsillarum serovar 7 strains (approximately 106 CFU per pig). In the CY-treated group, both circulating neutrophil and lymphocyte counts decreased, whereas in the DM-treated group, lymphocyte counts decreased but neutrophil counts increased. During the observation period, none of the CY- or DM-treated pigs developed clinical signs or gross lesions, as well as non-treated pigs. Growth agglutination antibody titres in all pigs remained unchanged. Our findings indicate that E. tonsillarum strains are avirulent for swine, regardless of immune status. 相似文献
70.
Promotion of initial swim bladder inflation and effect of initial inflation failure on skeletal malformation in cultured seven‐band grouper Hyporthodus septemfasciatus (Thunberg) 下载免费PDF全文
下载免费PDF全文 Masaharu Tsuji Susumu Uji Yasushi Tsuchihashi Kazuhiro Okada Takeshi Kawamura Takashi Katoh Tohru Kasuya Takuo Nigo Atsushi Hamabe Atsushi Miyamoto Sahoko Nakamura Akiko Nakano Yoshifumi Sawada 《Aquaculture Research》2016,47(6):1954-1971
The effects of the removal of the oily surface film on initial swim bladder inflation and survival in cultured seven‐band grouper Hyporthodus septemfasciatus were investigated during the larval stage. Additionally, the relationship between swim bladder inflation failure and malformations in later stages was examined. To explore promotion conditions for inflation, duplicate experiments were conducted under three different water surface conditions: removal of the oily surface film (ROF group), covering the water surface with an oil film (COF group), and sealing the water surface with liquid paraffin (SLP group). Larval swim bladder inflation was first observed 14 days after hatching (DAH) in the ROF group; thereafter, swim bladder inflation rates increased to 11.1% and 38.7% until the end of the experiments. This indicates that initial swim bladder inflation occurs at the pre‐flexion stage in larval development. Conversely, bladder inflation was rarely observed in the COF or SLP groups, indicating the promotional effect of surface film removal on larval swim bladder inflation and suggesting that gulping atmospheric air is necessary for initial inflation. Although larval water surface death occurred frequently in the ROF group, no significant difference existed in any group between the survival rates at 10 DAH and at the end of the experiment. The incidence rate of spinal curvature and deformation of the centra was significantly higher in individuals without initial swim bladder inflation, and these malformations mainly occurred in the caudal vertebra. Therefore, the removal of the oily surface film promotes initial swim bladder inflation and reduces larval malformations. 相似文献