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1.
Nguyen Vu SON James Kenn CHAMBERS Makoto NAKATA Yasutsugu MIWA Hiroyuki NAKAYAMA Kazuyuki UCHIDA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2022,84(2):208
This report described the histopathological and immunohistochemical features of cutaneous mast cell tumor (MCT) in six hedgehogs. The hedgehogs presented single cutaneous mass with ulcer and crusting. Histologically, the neoplastic lesions were characterized by the proliferation of well-differentiated mast cells (3 cases), and atypical mast cells (3 cases) with one atypical histiocytic morphology. Immunohistochemically, tumor cells were positive for KIT and mast cell tryptase, and were negative for Iba-1. In well-differentiated MCT, all patients were clinically improved and survived more than 365 days after surgical excision, whereas an atypical histiocytic MCT showed aggressive behavior with re-recurrence, and the animal died 115 days after surgery. These findings suggest that, compatible with other animals, well-differentiated MCT has a better prognosis in hedgehogs. 相似文献
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内蒙古中东部野生扁蓿豆种子硬实性的研究 总被引：1，自引：0，他引：1
扁蓿豆是抗逆性极强的优良牧草,但其种子发芽率低,具有65 %～75 %的硬实。在恒温25℃时发芽率较高,在变温20 ～30℃时发芽率最高,若温度超过30℃或低于15℃时发芽被抑制,但短时间高温处理有利于促进发芽。采用机械或浓硫酸处理,发芽率分别比对照高40.6 %和45.6 %。野生种子的硬实率与采集地气温,特别是与7月份温度有着很高的正相关关系,而且不同产地的种子表现出较大的差异,以赤峰市北部采到的居群硬实率最高,比呼和浩特市采集的居群高9 %。随着储藏年限的推移,种子的硬实率不断下降,发芽率增加,储藏3.5年的种子发芽率达到了67.0 %,表明扁蓿豆种子采集后通过室温储藏可以达到提高发芽率的效果。 相似文献
3.
Tsukasa OKANO Katsuhi NAKATA Yumiko NAKAYA Takashi NAGAMINE Manabu ONUMA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(6):637-642
The Ryukyu long-furred rat, Diplothrix legata, is a large rodent
distributed only on Amami-ohshima Island, Tokuno-shima Island and Okinawa-jima Island,
Japan. This animal is endangered as a result of deforestation, predation by introduced
carnivores and mortality caused by vehicles. We performed theriogenological examinations
of 32 male and 25 female Ryukyu long-furred rats carcasses collected from wild populations
on northern Okinawa-jima Island from December 2005 to September 2013. Adult males had
remarkably large preputial glands. Seminiferous diameter of adult was significantly small
(136 ± 28 µm, n=8) from April to August. Numerous spermatozoa were
observed from September through February, and seminiferous diameter was significantly
large (216 ± 27 µm, n=12) during this time in adults; testes length
changed in a similar pattern. These findings indicate that the mating season may occur
from September through February. Size (body length) at sexual maturity was estimated to be
>560 mm in both sexes. From observation of corpora lutea and placental scars, litter
size was estimated to range from 2 to 12 (average=6, n=4). These results provide
fundamental knowledge that will be beneficial for in situ and ex
situ conservation of this rare species. 相似文献
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ABSTRACT: This study explored the fundamental process that controls interannual change in plankton biomass on the Pacific coast of Japan, focusing on the spring period of shirasu fishery. A 1-D model of primary production revealed that the strength of horizontal advection induced by warm water intrusion from the Kuroshio into the Pacific coast is the most critical for plankton biomass compared with other factors such as diffusion and production. This conclusion was also confirmed by a sensitivity analysis of the model. 相似文献
6.
ABSTRACT: The appropriate water velocity in artificial burrows for theJapanese crayfish species Cambaroides japonicus was studied.An experimental system of two artificial burrows (burrows A and B)of the same size was set in a large tank. The velocity of burrowA was 0 cm/s and that of burrow B was varied andset at 0 cm/s, 5 cm/s, 10 cm/s,20 cm/s and 30 cm/s. The selectionof these two burrows by C. japonicus was observed. No animalsselected burrow B significantly more than burrow A above 10 cm/s.At 20 cm/s, some crayfishes were swept away andcould not return to burrows because of the high water velocity.At 30 cm/s, most animals were swept away. We concludethat the appropriate water velocity for the suitability of artificialburrows and the immediate foraging area adjacent to the burrowsshould be as low as 5 cm/s. 相似文献
7.
Daisuke FUKUI Masashi NAGANO Ryohei NAKAMURA Gen BANDO Shinichi NAKATA Masao KOSUGE Hideyuki SAKAMOTO Motozumi MATSUI Yojiro YANAGAWA Yoshiyuki TAKAHASHI 《The Journal of reproduction and development》2013,59(5):491-495
Artificial insemination (AI) can help to avoid inbreeding and genetic degeneration
for sustaining genetically healthy populations of endangered species in captivity.
Collection of a sufficient quantity of viable sperm is an essential first step in the
AI process. In the present study, we examined the effects of frequent
electroejaculation on semen characteristics in a Siberian tiger. We collected semen
in all 17 trials during 6 breeding seasons (6 years). The mean number of sperm and
the percentage of motile sperm were 294.3 ± 250.2×106/ejaculate and 82.4 ±
11.4%, respectively. The number of motile sperm tended to increase during frequent
electroejaculation in the same breeding season. Semen collection by
electroejaculation can be performed effectively up to the fourth sequential
ejaculate, which contained the most sperm in the study. In conclusion, frequent
collection of sperm by electroejaculation from tigers may be effective for collection
of a large number of motile sperm. 相似文献
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Andrew KATABA Shouta M.M. NAKAYAMA Yared Beyene YOHANNES Haruya TOYOMAKI Hokuto NAKATA Yoshinori IKENAKA Mayumi ISHIZUKA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(11):1674
Lead (Pb) exposure occurs together with other metals including zinc (Zn). This study investigated the impact of Zn on Pb tissue accumulation and Pb-induced toxicities. Animals (n=6 rats per group) were exposed to lead acetate (PbAc) or a combination of PbAc and zinc acetate (ZnAc) under the following groups: control (deionized water), low PbAc [12 mg/kg PbAc (3 mg PbAc/rat/day)], low PbAc–ZnAc [12 mg/kg PbAc (3 mg PbAc/rat/day) + 0.2 mg ZnAc/rat/48 hr], high PbAc [120 mg/kg (30 mg PbAc/rat/day)], and high PbAc–ZnAc [120 mg/kg (30 mg PbAc/rat/day) + 1 mg ZnAc/rat/48 hr] for 8 weeks. A significant reduction in body weight gain was observed in the high PbAc group relative to the control group. Muscles and testes both had reduced and increased Pb uptake in low PbAc–ZnAc and high PbAc–ZnAc groups compared to PbAc only groups, respectively. Bone Pb levels in the high PbAc–ZnAc group were lower than the high PbAc group. Zinc co-administration attenuated Pb-induced inhibition of delta aminolaevulinic acid dehydratase enzyme and enhanced catalase enzyme activity at a high level of exposure. Moreover, ZnAc seems to have minimized the effects of Pb-induced mRNA dysregulation in antioxidant and antiapoptotic enzymes encoding genes. Heme oxygenase-1 was downregulated in the kidney and brain in the low PbAc group. Liver glutathione peroxidase and thioredoxin reductase-1 were downregulated in the high PbAc group. These findings suggest that zinc co-administration with lead may partially mitigate against Pb-induced toxicities. 相似文献
10.
Yohei Kawauchi Masayuki Chimura Takashi Mutoh Masamichi Watanobe Hokuto Shirakawa Kazushi Miyashita 《Fisheries Science》2014,80(2):139-149
We examined factors affecting the vertical distribution of juvenile walleye pollock during “the second critical period” (i.e. the transition period of prey size) in and around Funka Bay, Hokkaido, Japan. During the day, small juveniles (<30 mm) were distributed mainly in shallow, warm, and low-salinity water within the bay, whereas larger ones (≥30 mm) occurred in deeper, cold and saline water. During the night, the large juveniles migrated to shallower depths. Outside the bay, small- and large-sized juveniles were distributed in water masses of similar physical properties during the daytime, whereas during the nighttime, most of the juveniles moved to shallower depth, and some juveniles dived to deeper water mass. Dietary analysis revealed that large juveniles fed on large copepods (≥0.5 mm in body width) more than small juveniles did. The composition of zooplankton in our survey area showed that large-sized copepods often occurred in deeper saline water. From these results, there is a possibility that juvenile pollock inside and outside Funka Bay occupied different water masses preferable for each feeding advantage. 相似文献