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Robert Manuel L. Juárez-Gómez Juan Chaires-Pacheco Mariana Peña-Ramírez Yuri J. 《New Forests》2020,51(2):335-347
New Forests - Spanish red cedar, Cedrela odorata L. (Meliaceae), is a valuable timber tree in tropical American forests. Existing demand for elite individuals endangers the conservation of... 相似文献
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Yuichi Kinoshita Katsuhiko Yoshizawa Yuko Emoto Michiko Yuki Takashi Yuri Nobuaki Shikata Susan A. Elmore Airo Tsubura 《Journal of toxicologic pathology》2016,29(1):53-59
Primary ovarian tumors are generally uncommon in rats used in toxicologic studies. A malignant Sertoli cell tumor was present in the ovary of a 19-week-old female Sprague Dawley rat. Macroscopically, the mass was white and firm, 10 × 13 × 17 mm in size, and located in the right ovary. Histopathologically, the mass was composed of nests of pleomorphic cells, which formed seminiferous-like tubules separated by a thin fibrovascular stroma. The tubules were lined by tumor cells, which had basally located nuclei and abundant eosinophilic and vacuolated cytoplasm. In some areas, the tumor cells were arranged in a retiform growth pattern, mimicking a rete testis/ovarii. Disseminated metastases to the surfaces of the mesentery, spleen and liver were also present. Immunohistochemically, many tumor cells were strongly positive for vimentin, estrogen receptor α and Ki 67. Some tumor cells were positive for pancytokeratin and inhibin α. These findings closely resemble those of an ovarian-derived human malignant Sertoli cell tumor. From our review of the literature, we believe this is the first report of a spontaneous malignant Sertoli cell tumor in the ovary of a young laboratory rat. This case might provide useful historical control information for rat toxicity studies. 相似文献
5.
Sugisawa H Itou T Ichimura Y Sakai T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(12):1113-1116
Bovine milk contains various immunoreactive components, and the activation of polymorphonuclear leukocytes (PMNLs) function in breast-fed infants has been reported. In this study, the effect of milk on the oxidative burst of bovine PMNLs was investigated in vitro. When PMNLs were incubated with 0.1% colostrum or normal milk, the oxidative burst induced by serum-opsonized Staphylococcus aureus was enhanced, and the enhancement declined dose-dependently. The enhancement of the oxidative burst by milk was not due to opsonins but the priming activities. Also, the phorbol 12-myristate 13-acetate (PMA)-induced oxidative burst increased after incubation with 0.1% colostrum, but the colostral enhancement of the oxidative burst was unaffected by the incubation time. These results suggest that bovine milk contains oxidative burst promoting factor(s). 相似文献
6.
Yuri Zharikov David B. Lank Falk Huettmann Russell W. Bradley Nadine Parker Peggy P. -W. Yen Laura A. Mcfarlane-Tranquilla Fred Cooke 《Landscape Ecology》2006,21(1):107-120
We studied habitat selection and breeding success in marked populations of a protected seabird (family Alcidae), the marbled
murrelet (Brachyramphus marmoratus), in a relatively intact and a heavily logged old-growth forest landscape in south-western Canada. Murrelets used old-growth
fragments either proportionately to their size frequency distribution (intact) or they tended to nest in disproportionately
smaller fragments (logged). Multiple regression modelling showed that murrelet distribution could be explained by proximity
of nests to landscape features producing biotic and abiotic edge effects. Streams, steeper slopes and lower elevations were
selected in both landscapes, probably due to good nesting habitat conditions and easier access to nest sites. In the logged
landscape, the murrelets nested closer to recent clearcuts than would be expected. Proximity to the ocean was favoured in
the intact area. The models of habitat selection had satisfactory discriminatory ability in both landscapes. Breeding success
(probability of nest survival to the middle of the chick rearing period), inferred from nest attendance patterns by radio-tagged
parents, was modelled in the logged landscape. Survivorship was greater in areas with recent clearcuts and lower in areas
with much regrowth, i.e. it was positively correlated with recent habitat fragmentation. We conclude that marbled murrelets
can successfully breed in old-growth forests fragmented by logging. 相似文献
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Reliable information on weed abundance and distribution within fields is essential for weed management in agricultural systems. Such information is necessary to adopt localized and variable rates of herbicide spraying, thus reducing chemical waste, crop damage, and environmental pollution. This paper examined the potential of airborne multispectral imagery to discriminate and map weed infestations in an experimental citrus orchard in Japan. Using an airborne digital sensor, multispectral imagery was acquired over the study site on 10 April 2003. The obtained reflectance imagery was analyzed using an image object-based approach in eCognition. After creating image objects on the image, the spectral information for weeds and citrus, represented by corresponding selected sample image objects, was extracted. Significant differences in the spectral characteristics between weeds and citrus were observed in each of the red, green, and blue wavebands. The simple average values of these wavebands were used to classify image objects with the nearest neighbor algorithm. Maps were generated with different classes or levels of class groups. A subsequent accuracy assessment demonstrated that the weeds were successfully discriminated from other image objects with a classification accuracy of 99.07%. Therefore, maps generated based on the classification result could provide valuable information for developing a site-specific weed management program for the study orchard. 相似文献
9.
Tomo’omi Kumagai Koichiro Kuraji Hironori Noguchi Yuri Tanaka Katsunori Tanaka Masakazu Suzuki 《Journal of Forest Research》2001,6(4):257-264
Environmental factors, such as global solar radiation, wind speed, air temperature, humidity, and CO2 concentration, were measured above and within the canopy of a tropical rainforest in Lambir Hills National Park, Sarawak,
Malaysia. Few data concerning the environment of this forest have been reported. Intensive observations were carried out in
1998, 1999, and 2000 with the following results: (1) The fraction of global solar radiation reaching the upper layer of the
canopy varied with global solar radiation above the canopy. Even though the global solar radiation above the canopy fluctuated,
the fraction of that reaching the lower canopy and the ground was constantly approximately 5%. (2) The fraction of wind speed
reaching each layer of the canopy increased with wind speed above the canopy. Little wind was usually present at the lower
canopy. (3) The daytime air temperature at the canopy top was higher than that near the ground. The maximum difference between
the air temperature at the canopy top and that at the ground was about 5°C, and the diurnal temperature ranges at the canopy
top and those at the ground were about 8°C and about 5°C, respectively. The highest daytime water vapor pressure occurred
within the canopy and particularly near the ground. Vertical gradients of water vapor pressure during the day were steep,
probably because of high transpiration. (4) In the 1998 observation the minimum and the maximum CO2 concentrations were 360 ppm in the day and 450 ppm at night, while in the 2000 observation the minimum and the maximum CO2 concentrations were 350 ppm in the day and 540 ppm at night. The higher CO2 concentration in the daytime and the lower concentration at night observed during the 1998 observation period were probably
due to reduced photosynthesis and soil respiration caused by exceptional dry conditions during the observation period. 相似文献
10.
Kosei SAKAI Tomohiro YONEZAWA Hideyuki YAMAWAKI Toshifumi OYAMADA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(10):1319-1322
Somatostatin receptor 2 (SSTR2) is a negative regulator of cell proliferation in human
breast cancer. Since there is little information about SSTR2 in canine mammary gland tumor
(MGT), we clarified its distribution and expression level in normal mammary gland, benign
MGT and malignant MGT. SSTR2 expression determined by immunohistochemical staining was
observed in the cytoplasm of luminal epithelial cells. The intensity was negatively
correlated with malignancy: normal tissues and some of the benign tumors had the highest
levels, while the malignant tumors had little or no SSTR2 expression. As for the Western
blotting, SSTR2 protein level in benign tumors was significantly lower than the normal
mammary gland. On the other hand, SSTR2 protein levels in two of three malignant tumors
were higher than the other groups. These results suggest that SSTR2 expression alters
according to the malignancy of canine MGT. 相似文献