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61.
Sediment discharge is a serious problem in the weathered granite mountains of southern China. Human activities, such as the harvesting of ferns and litter for fuel, are the main source of sediment, but the details of the processes and mechanisms leading to sediment discharge are unclear. Data on sediment yields, percentages of peak storm runoff and fern undergrowth and litter cover extent in the two basins—one a control from which people have been excluded since 1997, and the other where normal harvesting practices are permitted—were used to evaluate how human activity affects sediment discharge. The annual sediment discharge decreased immediately after implementing control practice, despite no marked changes in the 4 years after 1997 in the percentages of peak storm turnoff and the fern and litter cover extent and density. The 4-year period of control practice was too short to affect the relationship between peak rainfall and peak storm runoff and the fern and litter covers and their amounts, but long enough to contribute to the reductions in sediment discharge in the control basin by decreasing erodibility. Thus, sediment discharge was probably reduced to some extent by the elimination of human impacts even though a well-developed vegetation layer did not develop. 相似文献
62.
ABSTRACT: Presence–absence sampling (PAS) is a sampling technique that observes only the presence or absence of objects, such as eggs, in sampling units. The purpose of the present paper was to study the oversight probability in a PAS study for detecting fish eggs in connection with the spatial distribution of eggs. It was shown that the oversight probability of presence of eggs under no-eggs observation is a monotone decreasing function of the parameter of the degree of contagion. 相似文献
63.
Naoaki YAMADA Takashi KITAMORI Fumiyo KITAMORI Kanako ISHIGAMI Koji IWANAGA Taiki ITOU Ryosuke KOBAYASHI Shino KUMABE Takuya DOI Junko SATO Yumi WAKO Minoru TSUCHITANI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(10):1299-1303
A 7-year-old female boxer dog died suddenly without any clinical signs. It was suspected
that the dog had arrhythmogenic right ventricular cardiomyopathy (ARVC) due to ventricular
premature complexes and ventricular tachycardia at 3 years of age. The final diagnosis of
ARVC was confirmed by histological characteristics, such as loss of cardiocytes and
fibrofatty replacement, occurring in the right and left ventricular walls. In the
cardiocytes, non-lipid vacuoles were observed. Cardiac fibrosis and intimal thickening of
the small arteries occurred without fatty replacement in the inner muscle layer including
the papillary muscles of the left ventricular wall. This paper describes the
pathomorphological details of an ARVC case with coincidental cardiac fibrosis in the inner
muscle layer of the left ventricular wall. 相似文献
64.
Yuuki ISAJI Koki YOSHIDA Hiroshi IMAI Masayasu YAMADA 《The Journal of reproduction and development》2015,61(6):503-510
In mouse somatic cell nuclear transfer (SCNT), polyvinylpyrrolidone (PVP) is typically included in the
nuclear donor injection medium. However, the cytotoxicity of PVP, which is injected into the cytoplasm of
oocytes, has recently become a cause of concern. In the present study, we determined whether bovine serum
albumin deionized with an ion-exchange resin treatment (d-BSA) was applicable to the nuclear donor injection
medium in SCNT as an alternative to PVP. The results obtained showed that d-BSA introduced into the cytoplasm
of an enucleated oocyte together with a donor nucleus significantly enhanced the rate of in
vitro development of cloned embryos to the blastocyst stage compared with that of a conventional
nuclear injection with PVP in SCNT. We also defined the enhancing effects of d-BSA on the blastocyst formation
rate when d-BSA was injected into the cytoplasm of oocytes reconstructed using the fusion method with a
hemagglutinating virus of Japan envelope before oocyte activation. Furthermore, immunofluorescence experiments
revealed that the injected d-BSA increased the acetylation levels of histone H3 lysine 9 and histone H4 lysine
12 in cloned pronuclear (PN) and 2-cell embryos. The injection of d-BSA before oocyte activation also
increased the production of cloned mouse offspring. These results suggested that intracytoplasmic injection of
d-BSA into SCNT oocytes before oocyte activation was beneficial for enhancing the in vitro
and in vivo development of mouse cloned embryos through epigenetic modifications to nuclear
reprogramming. 相似文献
65.
Kasumi SUDO Manabu YAMADA Mariko OCHIAI Shoko IWAMOTO Hajime SAKAKI Chiho KUSHIDA Maiko YAMASHITA Atsushi YAMAMOTO Takao NAGASAKA Mikio OIDEMIZU Akito SAITO Kinya YAMAMOTO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(6):990
We evaluated the role of classical swine fever virus (CSFV) in the formation of button ulcers in the mucosa of the gastrointestinal tract. Histopathological and immunohistochemical analyses of pigs experimentally infected with a subgenotype 2.1 isolate of CSFV, which was isolated in Japan in 2019, revealed follicular necrosis in the submucosal mucosa-associated lymphoid tissue and herniation of crypts as factors that contribute to the development of button ulcers during CSFV infection. These findings indicate that CSFV induces follicular necrosis and is one of the causative agents of button ulcers in pigs. 相似文献
66.
Maya OI Keisuke YAMADA Hiroyuki HAYAKAWA Hiroshi SUZUKI 《The Journal of reproduction and development》2013,59(1):92-96
Effective preselection of sex has been accomplished in several species of livestock and
also in humans using the flow cytometric sperm sorting method. A guaranteed high sorting
accuracy is a key prerequisite for the widespread use of sperm sexing. The standard
validation method is flow cytometric remeasurement of the DNA content of the sexed sperm.
Since this method relies on the same instrument that produced the original sperm
separation, it is not truly independent. Therefore, to be able to specifically produce
either male or female offspring in the dog, we developed a method of direct visualization
of sex chromosomes in a single sperm using fluorescence in situ
hybridization (FISH) as a validation method. Denaturation of canine spermatozoa by
immersion in 1 M NaOH for 4 min yielded consistent hybridization results with over 97%
hybridization efficiency and a good preservation of sperm morphology. There was no
significant difference between the theoretical ratio (50:50) and the observed ratio of X-
and Y-chromosome-bearing spermatozoa in any of the three dogs. In addition, the mean
purities of flow-sorted sex chromosomes in spermatozoa of the three dogs were 90.8% for
the X chromosome fraction and 89.6% for the Y chromosome fraction. This sorting was
evaluated by using the dual color FISH protocol. Therefore, our results demonstrated that
the FISH protocol worked reliably for both unsorted and sexed sperm samples. 相似文献
67.
Mst. Parvin MOSTARI Nahoko IEDA Chikaya DEURA Shiori MINABE Shunji YAMADA Yoshihisa UENOYAMA Kei-ichiro MAEDA Hiroko TSUKAMURA 《The Journal of reproduction and development》2013,59(3):266-272
Accumulating evidence suggests that the arcuate nucleus (ARC) kisspeptin/neurokinin B
(NKB)/dynorphin (KNDy) neurons play a role in estrogen negative feedback action on
pulsatile gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH) release. The
present study aimed to determine if dynorphin (Dyn) is involved in estrogen negative
feedback on pulsatile GnRH/LH release. The effect of the injection of nor-binaltorphimine
(nor-BNI), a kappa-opioid receptor (KOR) antagonist, into the third cerebroventricle (3V)
on LH pulses was determined in ovariectomized (OVX) adult female rats with/without
replacement of negative feedback levels of estradiol (low E2). The mean LH
concentrations and baseline levels of LH secretion in nor-BNI-injected, low
E2-treated rats were significantly higher compared with vehicle-treated
controls. On the other hand, the nor-BNI treatment failed to affect any LH pulse
parameters in OVX rats without low E2 treatment. These results suggest that Dyn
is involved in the estrogen negative feedback regulation of pulsatile GnRH/LH release. The
low E2 treatment had no significant effect on the numbers of ARC
Pdyn (Dyn gene)-,Kiss1- and
Tac2 (NKB gene)-expressing cells. The treatment also did not affect
mRNA levels of Pdyn and Oprk1 (KOR gene) in the
ARC-median eminence region, but significantly increased the ARC kisspeptin
immunoreactivity. These findings suggest that the negative feedback level of estrogen
suppresses kisspeptin release from the ARC KNDy neurons through an unknown mechanism
without affecting the Dyn and KOR expressions in the ARC. Taken together, the present
result suggests that Dyn-KOR signaling is a part of estrogen negative feedback action on
GnRH/LH pulses by reducing the kisspeptin release in female rats. 相似文献
68.
Rumi Kaida Tomomi Kaku Kei’ichi Baba Masafumi Oyadomari Takashi Watanabe Sri Hartati Enny Sudarmonowati Takahisa Hayashi 《Journal of Wood Science》2009,55(5):381-386
We examined the saccharification and fermentation of meals from Acacia mangium wood, Paraserianthes falcataria wood, and Elaeis guineensis trunk. The levels of enzymatic hydrolysis of cellulose and ethanol production were highest for P. falcataria wood and lowest for A. mangium wood. Ultrasonication pretreatment of meal further increased the rates of hydrolysis and ethanol production in meal from
P. falcataria wood. Through this pretreatment, hemicelluloses (xylan and xyloglucan) and cellulose were released in the meal from P. falcataria wood. Loosening of hemicellulose associations can be expected to make P. falcataria wood more useful for bioethanol production. 相似文献
69.
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
70.
We investigated the temporal changes in creep and stress relaxation behavior in both microscopic crystalline cellulose and macroscopic strain of wood specimen using Japanese cypress (Chamaecyparis obtusa Endl.) to understand the viscoelastic properties of wood cell walls. Specimens 600 µm in thickness were observed by the X-ray diffraction and submitted to tensile load. The crystal lattice strain of (004) plane and macroscopic strain of specimen were continuously detected during creep and stress relaxation tests. It was found that the creep compliance based on macroscopic strain showed a gradual increase after instantaneous deformation due to loading and then the parts of creep deformation remained as permanent strain after unloading. On the other hand, crystal lattice strain showed a different behavior for macroscopic strain; it kept a constant value after instantaneous deformation due to loading and then increased gradually after a certain period of time. These differences between macroscopic and microscopic levels were never found in the stress relaxation tests in this study. Relaxation modulus at the macroscopic level only showed a decreasing trend throughout the relaxation process. However crystal lattice strain kept a constant value during the macroscopic relaxation process. In addition, the microfibril angle (MFA) of wood cell wall has a role of mechanical behavior at microscopic level; crystal lattice strains were smaller with increasing MFA at both creep and relaxation processes. Creep compliance and stress relaxation modulus at the macroscopic level decreased and increased with increasing MFA, respectively. Our results on the viscoelastic behavior at microscopic level evidenced its dependency on MFA. 相似文献