Temporal water deficit and wood formation in Cryptomeria japonica     

Abe H  Nakai T  Utsumi Y  Kagawa A 《Tree physiology》2003,23(12):859-863

Cell behavior in the cambium and developing xylem of 3-year-old Japanese cedar (Cryptomeria japonica D. Don.) trees, during and after an 11-day suspension of irrigation, was analyzed. Leaf xylem pressure potential and tangential strain of the stem surface were monitored throughout the experiment. Anatomical features and numbers of developing tracheids and cambial cells were observed in four trees, sampled on Days 0, 4, 8 and 11 after irrigation was suspended. Daytime xylem pressure potential decreased to -1.9 MPa on Day 7 and remained the same until irrigation was resumed on Day 11. The transverse dimensions of the tracheids, which began to form secondary walls, began to decrease on Day 4. The number of cells in the cambial zone and cell expansion zone decreased abruptly on Day 8. Tangentially aligned developing tracheids with collapsed cell walls were observed in samples harvested on Days 8 and 11. Secondary wall formation was recognized in these tracheids. After the resumption of irrigation, xylem pressure potential recovered rapidly to the same value as before the suspension of irrigation. Tangential strain increased within 30 min after the resumption of irrigation, and continued to increase until the onset of light the next day. Eighteen days after the resumption of irrigation, anatomical features of cells in the cambium and cell-expansion zone were similar to those observed before suspension of irrigation.  相似文献   

Analyses of leaves from open field-grown transgenic poplars overexpressing xyloglucanase     

Tomomi Kaku  Kei’ichi Baba  Toru Taniguchi  Manabu Kurita  Ken-ichi Konagaya  Katsuaki Ishii  Teiji Kondo  Satoshi Serada  Haruka Iizuka  Rumi Kaida  Teruaki Taji  Yoichi Sakata  Takahisa Hayashi 《Journal of Wood Science》2012,58(4):281-289

The transgenic expression of Aspergillus xyloglucanase cDNA (AaXEG2) with 35S promoter in the leaves of open field-grown poplars was studied. The level of xyloglucan in the transgenic poplars was decreased to 15–16% in the non-fertile soil (forest-field soil) and to 21–22% in the fertile soil (farming-field soil) compared with that of the wild-type poplars. The leaves exhibited a smaller surface area with more rounded teeth than those of the wild-type plants, similar to the sun leaf variety that was grown in the incubation room and subsequently greenhoused. The majority of total veins with water-conducting vascular bundles were shorter in the leaves of the transgenic poplars than those of the wild type. This decrease in vein length may result from a decrease in xyloglucan during leaf development, from which large numbers of proteins were markedly downregulated in the leaves of the transgenic plants via proteomic analysis. It seems likely that the leaves of the transgenic poplars came to relax the edges of their tooth rather than extend their veins as a result of the loosening of the xyloglucan cellulose networks in the leaves.  相似文献   

Chronological analysis of canine parvovirus type 2 isolates in Japan     

Ohshima T  Hisaka M  Kawakami K  Kishi M  Tohya Y  Mochizuki M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(8):769-775

Fifty-five canine parvovirus type 2 (CPV) samples, 12 fecal specimens and 43 cell culture isolates, were examined for their genetic characteristics of VP2 gene. They were collected from the diseased dogs at various districts of Japan during 27 years from 1980 to 2006. A fragment of VP2 gene was analyzed by restriction fragment length polymorphism assay and DNA sequencing. The original antigenic type 2 of CPV (CPV-2) was no longer found in the samples since 1984, and two antigenic variants CPV-2a and CPV-2b replaced CPV-2 as predominant types for about 5 years from 1982. A new genetic variant of prototype CPV-2a with non-synonymous substitution at the VP2 amino acid residue 297 from Ser to Ala was first detected in 1987. New CPV-2b with the same amino acid substitution at position 297 as new CPV-2a was also detected from the samples collected in 1997. Since then new CPV-2b has been the predominant CPV over the field of Japan. Several additional amino acid substitutions were detected in the VP2 gene of some recent CPV strains. Neither CPV-2c(a), CPV-2c(b), nor "Glu-426" of the antigenic variants previously found outside the country was detected in any samples tested. Reactivity of new CPV-2a and 2b variants against antibodies produced by the current vaccine products was determined by a cross hemagglutination-inhibition test. The recent field CPV isolates reacted more efficiently to the antibodies produced in dogs vaccinated with the new CPV-2b vaccine strain than the conventional CPV-2 vaccine strain.  相似文献   

Piezoelectric behavior of wood under combined compression and vibration stresses I: Relation between piezoelectric voltage and microscopic deformation of a Sitka spruce (Picea sitchensis Carr.)     

Takahisa Nakai  Naoyasu Igushi  Kose Ando 《Journal of Wood Science》1998,44(1):28-34

This study investigated the relation between piezoelectric behavior and the deformation of trachieds in real time under combined compression and vibration stresses. Scanning electron microscope images were recorded directly into a video recorder. Two types of microscopic destruction were observed in the specimens. With the first type, although a small uprush around the boundary of the annual ring was observed, the specimens were broken only by shearing fracture in the 45° direction. With the second type, the specimens were finally broken by shearing fracture after repeated buckling. In these cases the piezoelectric voltage increased almost linearly in the elastic region, proceeded to the maximal point, and then decreased gradually. Finally a clear peak appeared in the buckling and shearing fracture. There is a curved relation between the specific gravity and the piezoelectric parameter when the influence of voids is considered, and there is a linear relation between the dynamic Young's modulus and the piezoelectric parameter when the stress is considered.Part of this paper was presented at the 46th annual meeting of the Japan Wood Research Society in Kumamoto, April 1996  相似文献   

Effects of the lateral growth rate on wood quality parameters of Eucalyptus grandis from different latitudes in Brazil and Argentina     

Miho Kojima  Fabio Minoru Yamaji  Hiroyuki Yamamoto  Masato Yoshida  Takahisa Nakai 《Forest Ecology and Management》2009

Climate change resulting from increased atmospheric carbon dioxide (CO₂) and shortages of fossil fuels such as petroleum are major problems worldwide. Under these conditions, demand for woody biomass resources is increasing. We investigated the feasibility of using fast-growing Eucalyptus grandis for material production. Samples of E. grandis were collected from four plantations in different latitude divisions, including tropical and subtropical Brazil and subtropical Argentina. Various xylem qualities were measured and related to the lateral growth rate. Lateral growth rate did not significantly affect the longitudinal released strain of the surface growth stresses or the xylem density at any of the sampling sites. Higher lateral growth rate, higher values of xylem density, and lower absolute values of the released strain were observed in plantations closer to the equator. Higher growth rates in tropical climate promote longer fiber length. In subtropical plantations, smaller diameter trees will produce tension wood with smaller microfibril angles. Planting E. grandis closer to the equator thus produces higher quality wood than in plantations at lower latitudes.  相似文献   

Comparison of the accessory activity of murine peritoneal cavity macrophage derived dendritic cells and peritoneal cavity macrophages in a mixed lymphocyte reaction.     

L H Makala  Y Nishikawa  T Kamada  H Suzuki  X Xuan  I Igarashi  H Nagasaw 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(12):1271-1277

A detailed comparison of the accessory cell activities was carried out among murine peritoneal cavity macrophages (PEC-Mphi), peritonea] cavity macrophages stimulated with granulocyte-macrophage colony stimulating factor (GM-CSF) plus interleukin 4 (IL-4), the most popular cytokine combination widely used to generate dendritic cells (DC) and peritoneal cavity macrophage-derived DC (PEC-DC) using a two-way mixed lymphocyte reaction (MLR). All the cell types used efficiently induced statistically significant na?ve T cell proliferation at all culture time points and responder:stimulator ratios used. However, marked differences were noted in the magnitude of the proliferative responses. These variations may be attributed to the intensity of expression of MHC class II glycoproteins, as well as the actual numbers of MHC class II+ cells.  相似文献   

Squamous Cell Carcinoma in a Capybara (Hydrochoerus hydrochaeris)     

Takahisa HAMANO  Fumio TERASAWA  Yoshiharu TACHIKAWA  Atsuko MURAI  Takashi MORI  Khaled EL-DAKHLY  Hiroki SAKAI  Tokuma YANAI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(9):1301-1304

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Effects of selenium supplementation on plasma progesterone concentrations in pregnant heifers     

Hachiro Kamada  Itoko Nonaka  Naoki Takenouchi  Masahiro Amari 《Animal Science Journal》2014,85(3):241-246

It is known that selenium (Se) has various functions in animals. Many investigations on the biochemical and physiological effects of Se have been previously reported; however, the detailed function of Se in reproduction is not yet clear. We proposed the possibility that Se plays a notable role in progesterone production. The aim of this study was to clarify the effects of Se supplementation on progesterone levels of pregnant Holstein heifers. Eight Holstein heifers (?Se) were fed basal diet (containing 0.022 ppm of Se) throughout the experiment. While a 0.3 ppm diet of Se (sodium selenite) was fed to another seven animals (+Se) with basal diet. Blood sampling was carried out every week. Plasma Se concentrations were higher in Se‐supplemented cows compared with controls (?Se) (P < 0.01) throughout the experiment. Se supplementation increased plasma progesterone in the 29–39 weeks of pregnancy from 4.98 ± 0.64 to 6.86 ± 0.49 ng/mL on average (P < 0.05). The present findings suggest that Se contributes to maintaining the function of the corpus luteum and/or placenta in the latter period of pregnancy.  相似文献   

中国东南部利用铯-137观测荒坡土壤侵蚀的局限性     

TaroUchida  LiChanghua 《中国水土保持》2002,(7):36-36

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Ontogeny of pig discrete Peyer's patches: expression of surface antigens.     

L H Makala  T Kamada  H Nagasawa  I Igarashi  K Fujisaki  N Suzuki  T Mikami  K Haverson  M Bailey  C R Stokes  P W Bland 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(6):625-636

Leukocyte populations present in the discrete Peyer's patches (PP) of the pig were characterized from birth (Day 0) to day 35 after birth by immunohistochemistry and image analysis. Immediately after birth, cell membrane expression of CD2 and CD3, major histocompatibilty complex (MHC) class 11 (both SLA (swine leukocyte antigen) -DQ+ and SLA-DR+), CD21, 74-22-15 and surface immunoglobulin (sIg) were all demonstrable. Computer assisted morphometric techniques were used to confirm the significant expansion of these cell populations from birth onwards. The distribution of the cell types was not random but suggested a preferential retention of cells at specific sites. This implies a degree of organization of immunological cells within the discrete PP, enhancing the potential to mount immune responses in the most efficient manner.  相似文献