To study the growth and morphology of feline mammary epithelial cells in vitro, normal feline mammary tissues as well as cells collected from feline milk were cultured and examined using phase-contrast microscopy and immunohistochemistry. The method employed was a modification of Hiratsuka et al., and was found to be useful for the culture of dissociated feline mammary tissue. Small polygonal cells and large spindle-shaped cells that were positively stained with anti-keratin and anti-actin antibodies formed colonies with a pavement-like structure in culture of mid-pregnant mammary gland. Cultures of involuting mammary gland were composed mainly of small spindle-shaped cells, which were negative for keratin immunostaining and thought to be fibroblasts. Myofibroblasts, which participate in feline mammary carcinogenesis, and show keratin negative, actin positive, were not encountered in the present culture system of normal mammary gland. The cells from milk formed small colonies, but did not grow to reach confluent monolayer. 相似文献
To investigate the factors governing retention of pesticidal spray solutions on plant surfaces, a new retention model for droplets on solid surfaces has been introduced as where ΔΘ = Θa – Θr. The minimum sliding volumes (MiSV) of surfactant aqueous solutions (2 g litre?-1; surface tensions; 28·5 – 72·5 mN m?-1) on smooth surfaces of paraffin wax and polymer sheets were measured and the validity of the above retention equation was verified on combinations of these solutions and surfaces. A concept of the specific adhesional force (Fa) of a droplet was defined as which was the maximum adhesional force on a unit length of the width of the contact circle of a droplet, and Fa values of the solutions on the surfaces were compared. The predominant factors for droplet retention are discussed on the basis of this model. 相似文献
Caulogenic calli with a high differentiation potency were induced from mature embryos ofPicea jezoensis seeds stored over a long time, for 29 years, resulting in the active formation of adventitious buds. Embryos began to induce
calli within 3 weeks of cultivating on LP medium containing 3 μM BAP and 1 μM 2,4-D. Then, the calli proliferated and transformed
into caulogenic calli with bud primordia in 8 weeks. The caulogenic calli increased actively with the addition of 500 mg/l ofl-glutamine in the medium. Furthermore, caulogenic calli, induced on LP medium containingl-glutamine, resulted in the formation of adventitious buds, which elongated after transferring the calli into LP medium with
0.1 μM BAP, but withoutl-glutamine. It appears that the number of adventitious buds and the process of shoot elongation are influenced by the kind
of nitrogen contained in the medium for callus induction.
A part of this study was presented at the 107th Annual Meeting of the Japanese Forestry Society (1996). 相似文献
Photosynthetic induction responses to abrupt increases in photon flux density (PFD) to 800 and 1500 &mgr;mol m(-2) s(-1) from either darkness or 100 &mgr;mol m(-2) s(-1) were examined in situ in leaves of Fagus crenata Blume, Daphniphyllum humile Maxim., and Acer rufinerve Siebold & Zucc. growing in a gap and the understory of an F. crenata forest. Among the species studied, F. crenata exhibited the highest assimilation rate (A(100)), stomatal conductance (g(s100)) at the background PFD of 100 &mgr;mol m(-2) s(-1), and A(100)/A(max) (A(max) = maximum assimilation rate), in both the gap and the understory. Time required for full induction depended on both background PFD and maximum PFD. The induction period was 2-4-fold shorter at a background PFD of 100 &mgr;mol m(-2) s(-1) than in darkness. For the three understory species, time required to full induction was 2-3-fold longer when irradiance was increased from darkness to 800 &mgr;mol m(-2) s(-1) than when irradiance was increased from darkness to 1500 &mgr;mol m(-2) s(-1). Acer rufinerve showed higher initial stomatal conductance (g(s0)) and a shorter induction period in the understory than in the gap. Fagus crenata exhibited a similar g(s0) and induction period in both habitats. Daphniphyllum humile demonstrated lower g(s0) and a longer induction period in the understory than in the gap. These findings indicate that initial stomatal conductance is closely correlated with the photosynthetic induction response. We conclude that the photosynthetic induction response is affected by the light conditions experienced by plants before the sudden increase in irradiance and by the extent of the increase in irradiance. 相似文献
A new wood preservative containing low molecular weight and low-toxicity silicic acid (LWSA) was investigated. To prevent
environmental pollution with the wood preservative, a silicic acid monomer aqueous solution (SAMS) or colloidal silicic acid
solution (CSAS) was combined with various metal compounds or boric acid. Agents where SAMS or CSAS was combined with boric
acid gave good protection against decay caused by the brown-rot fungus Fomitopsispalustris, the treated wood (Cryptomera japonica D. Don) specimens after the leaching test maintained a high resistance to decay. The leaching and decay tests revealed high
quantities of chemicals leaching from wood treated with SAMS-metal agents. However, when wood was treated with SAMS-boric
acid, there was little leaching of agent in either test. The mechanism of resistance of wood, which was treated with boric
acid mixed with CSAS or SAMS, to the brown-rot fungus F. palustris were investigated. When the concentration of boric acid was high, mycelial growth was inhibited completely and no protein
production was detected. When the amount of boric acid was low, the xylanase, mannase and cellulase activities were lower
than with control wood powder. When powdery boric acid was combined with CSAS, it was considered that the treated woods have
higher anti-weather properties than when boric acid-methanol solution was mixed with CSAS. The agent-preparation method adopted
should be considered carefully after taking the treatment process and the intended use of the preservative-treated wood into
account.
Received 26 September 2000
This study was supported by a Grant-in-Aid (09460079) for Scientific Research from the Ministry of Education, Science, and
Culture of Japan. 相似文献
We examined the relationship between the annual escapement of salmon and the δ15N of willow (Salix spp.) leaves to evaluate the contribution of marine-derived nutrients (MDN) to riparian vegetation around the Pacific Northwest
and Northeast regions. Foliar δ15N values ranged from −3.42‰ to 4.65‰. The value increased with increasing density of carcasses up to 500 fish/km and 1500
fish/km. δ15N values were variable at carcass densities below 500 fish/km. Possible factors affecting the fluctuation of δ15N at reference sites are: (1) denitrification; (2) the presence of N2-fixing trees, such as alder; and (3) agricultural runoff. δ15N values at the sites with carcass densities over 500 fish/km were consistently high, while a value of δ15N below zero was observed at only one site (Rusha River; δ15N = −1.87‰). At this site, most adult pink salmon returned to limited locations near the estuary because steeper channel gradients
acted as a migration barrier, resulting in the negative δ15N value. Nevertheless, we concluded that our results showed evidence of the feedback of MDN to terrestrial vegetation, although
the use of the δ15N value as a terrestrial end member at spawning sites is limited. If the relationship between the enrichment index, which
is expressed as the values using a mixing model, and salmon abundance was estimated, the availability of MDN in riparian ecosystems
could possibly be evaluated and will lead to the establishment of escapement goals.
An erratum to this article is available at . 相似文献
Coated paper-to-coated paper friction properties were examined in relation to printing runnability difficulties like erroneous
double feeding of paper sheets. Higher ratios of precipitated calcium carbonate (PCC) to clay in mixed pigment coatings resulted
in higher static and kinetic coefficients of friction (COFs). Microroughness in the order of pigment particle size is considered
to relate to COF, because cube-shaped particles of PCC resist sliding. Calendering decreased COF at larger amounts of PCC,
but did not change COF of the sole clay formulation at all. Addition of ground calcium carbonate (GCC) decreased COF. The
rate of decrease in kinetic COF with increasing number of sliding for the GCC-rich formulation was higher than that for the
PCC-rich formulation, presumably because protruding parts, characteristic of the GCC-rich formulation, on the surface were
selectively flattened. Addition of styrene-butadiene (SB)-latex up to 14pph decreased COF, but static COF had the highest
value at 18pph. The antislip property (as a rubber) of SB-latex developed only in the static mode. Among lubricants formulated,
the wax type decreased COF the most remarkably with more effect on kinetic COF than on static COF.
Part of this report was presented at the 11th International Printing and Graphic Arts Conference, Bordeaux, France, October
2002 相似文献
The geographic distributions ofCastanopsis sieboldii andCastanopsis cuspidata overlap each other on the Pacific coast of Japan, but on the Japan Sea coastC. sieboldii tends to dominate at similar temperatures. The authors attempted to explain this phenomenon by analyzing the effects of climatic
factors. Nuts were collected from the Pacific and Japan Sea coasts of the Kinki and Chugoku districts, and the nut characteristics
and the number of layers of epidermis in the leaves of the seedlings were investigated. The distribution ofC. sieboldii andC. cuspidata was satisfactorily explained by a multiple regression equation that was developed using three climatic factors: maximum snow
depth in winter, lowest temperature in the coldest month, and annual mean temperature, out of fourteen such factors that were
considered. The estimated distribution ofC. sieboldii andC. cuspidata from the multiple regression equation agreed with 66.2% of the actual observations. 相似文献
Natural forest recovery on abandoned farmland is hindered by a variety of factors and active restoration plays an important role when quick afforestation is desired. We investigated seedling survival of four transplanted native tree species (Quercus myrsinifolia, Quercus serrata, Aphananthe aspera, and Rhus sylvestris) by experimentally manipulating the vegetation cover, which was mainly dominated by dwarf bamboo (Pleioblastus chino), and herbivore access to the planting sites on farmland that had been abandoned for 15 years at the start of the study. Few transplanted seedlings of any species survived under intact vegetation cover, irrespective of herbivore presence. In gaps in the vegetation cover, winter browsing by Japanese hare (Lepus brachyurus) damaged all species. However, lower browsing frequency and higher resprouting ability after grazing of the seedlings enabled both Quercus species to survive better than the other species. These results indicate that dwarf bamboo and the hare jointly limit the establishment of native trees in old fields. If active afforestation by transplanting seedlings at sites dominated by dwarf bamboo is planned, a combination of vegetation removal, selection of suitable species, and temporary seedling protection will be most effective. 相似文献
A simple method to evaluate antioxidant activities of water-soluble ingredients of foods has been developed. Protective effects of antioxidants against hypochlorite radical or hydroxyl radical have been studied by comparing changes in absorbance of myoglobin (a standard reference) at 409 nm. Protective ratio, defined by absorbance changes of myoglobin with or without the antioxidant, was a good indicator to quantitatively evaluate the antioxidant activity against the hypochlorite radical or the hydroxyl radical, respectively. Radar charts indicating the antioxidant activities against DPPH (1,1-diphenyl-2-picrylhydrazyl), hypochlorite radical, and hydroxyl radical clearly differentiated the characteristics of five antioxidants including carnosine, glutathione, and vitamin C. By comparison of the radar charts, antioxidant activity of bonito meat hydrolysate was found to have similar characteristics to that of carnosine. The simple method proposed in this study would be useful for evaluating and characterizing the activities of water-soluble antioxidants contained in various food materials. 相似文献