Grouped, stacked rods and tapeta lucida in the retina of Japanese anchovy Engraulis japonicus     

Kamonpan Awaiwanont  Wisnu Gunarso  Munefumi Sameshima  Seiichi Hayashi  Gunzo Kawamura 《Fisheries Science》2001,67(5):804-810

ABSTRACT: Morphology of the photoreceptor cells and tapetum of the Japanese anchovy Engraulis japonicus was studied by histologically and by chemical analysis. The Japanese anchovy has a duplex retina. The cones form parallel rows consisting of alternately placed long cones and bifid cones. Both types of cones are intimately associated and form triple units that are regularly spaced along the row of cones. The rods are grouped and stacked. This fish has a retinal tapetum lucidum composed of guanine and hypoxanthine. Three structures of the tapetum lucidum were recognized: platelet, diamond and rod types. Photomechanical changes include movements of the photoreceptor cells and the retinal tapetum. The retina of the Japanese anchovy is thought to be highly sensitive and well adapted to a dim light environment.  相似文献   

The rescue of Epstein--Barr virus from primary cultured cells of nasopharyngeal carcinoma.     

M Takada  M Murata  M Takei  S Nakagawa  H Okumura  A Kawamura 《Comparative immunology, microbiology and infectious diseases》1979,2(2-3):177-189

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Regional variability in landscape effects on forest bird communities     

Spake  Rebecca  Soga  Masashi  Kawamura  Kazuhiro  Cooke  Robert S.  Yamaura  Yuichi  Eigenbrod  Felix 《Landscape Ecology》2020,35(5):1055-1071

Landscape Ecology - Functional responses to landscape heterogeneity are context-dependent, hampering the transferability of landscape-scale conservation initiatives. Japan provides a unique...  相似文献   

Effect of relationships among clinical mastitis incidence,reproductive performance,and culling rate on the lifetime of dairy cows at Hiroshima University Farm     

Yuzo Kurokawa  Miki Okita  Hirokazu Kubota  Yoshimasa Tsumiyama  Ichiro Chikamatsu  Akiyoshi Tanaka  Taketo Obitsu  Kensuke Kawamura 《Animal Science Journal》2021,92(1):e13591

Farm managers' decision to cull dairy cows is based on the cows' milk production, history of disorder(s), and reproductive performance, each of which affects dairy cows' lifetime (herd life and productive lifespan). We investigated the relationships among the incidence of clinical mastitis (CM), the reproductive performance, and the culling rate. We also assessed the effects of these relationships on the lifetimes of dairy cows, using the records made before and after the introduction of an automatic milking system (AMS) at Hiroshima University Farm. Milk yield, CM incidence density, and culling rate of dairy cows increased after the AMS introduction. The CM incidence was associated with an elongation of the calving interval in cows with the same parity. CM in the 1st parity might have caused the reductions of the cows' lifetime and their parity at culling. A higher age at first calving (AFC) was associated with an increase in culling rate but did not lead to a significant decrease in lifetime. Investigations of the factors mediating CM in the 1st parity or AFC with CM incidence or culling rate in the later stages might contribute to the control of lifetime of dairy cows.  相似文献   

Role of vision in behavior, visual field, and visual acuity of cuttlefish Sepia esculenta     

Naohiko Watanuki  Gunzo Kawamura  Shohei Kaneuchi and  Toru Iwashita 《Fisheries Science》2000,66(3):417-423

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Relationship between serum TNF activity and insulin resistance in dairy cows affected with naturally occurring fatty liver   总被引：2，自引：0，他引：2  

Ohtsuka H  Koiwa M  Hatsugaya A  Kudo K  Hoshi F  Itoh N  Yokota H  Okada H  Kawamura S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(9):1021-1025

To clarity the relationship between tumor necrosis factor (TNF) and insulin resistance in dairy cows affected with fatty liver, naturally occurring cases were investigated. The affected cows were classified into following three groups according to histopathologic findings of the liver: mild fat droplet deposition (group 1; n=11), severe fat droplet deposition (group 2; n=10), and cloudy swelling (group 3; n=8). Serum TNF activities in Group 2 (8.67 +/- 2.16 U/ml) and Group 3 (11.65 +/- 1.92 U/ml) were significantly higher than that in Group 1 (3.57 +/- 0.81 U/ml) (p<0.05). The insulin-tolerance tests showed that the insulin-stimulated glucose disposal rates (GDR) in Group 2 (27.6 +/- 7.8%) and Group 3 (15.8 +/- 9.1%) were significantly lower than that in Group 1 (41.7 +/- 9.8%). There was a significant negative correlation between serum TNF activity and GDR in affected cows (r=-0.56, p<0.01). These results indicate that serum TNF activity is correlated with insulin resistance in cows with fatty liver.  相似文献   

Clinical evaluation of growth hormone secretion in cattle using insulin tolerance test     

Oguro M  Ishikawa H  Ohtsuka H  Hoshi F  Kawamura S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(7):809-812

Growth hormone secretion was evaluated in cattle. Clinically healthy bovine growth hormone (bGH) concentrations were 10.7 +/- 1.6 ng/ml in Holstein and 7.8 +/- 3.9 ng/ml in Japanese black cattle. The bGH concentration alternated at three-hour intervals, and tended to be higher at midnight and lower in the morning and before feeding. Insulin tolerance test (ITT) at an insulin dosage of 0.25 U/kg showed a significant increase of bGH concentration to 331 +/- 153% at 60 to 90 min after injection. In ITT applied to five under-growth calves of Japanese black cattle, the basal bGH concentrations were lower and peak values after insulin injection were shown to be significantly low. The ITT is useful for the clinical examination of bGH secretion in cattle.  相似文献   

Hypertrophic cardiomyopathy in a mixed breed cat family     

Nakagawa K  Takemura N  Machida N  Kawamura M  Amasaki H  Hirose H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(7):619-621

A spayed female mixed cat (case 1) and its female offspring, the result of a pairing between case 1 and its male sibling, were diagnosed with hypertrophic cardiomyopathy (HCM). A pedigree survey revealed that the prevalence of HCM was at least 12.5% in the family, which was considered to be significantly higher than that in a hospital-based population (approximately 1.6%). Thus, this finding seems to support the suspected occurrence of familial HCM in this group of related cats.  相似文献   

A cytomegalovirus isolated from swine testicle cell culture   总被引：1，自引：0，他引：1  

J Shirai  M Narita  Y Iijima  H Kawamura 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1985,47(5):697-703

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Behavior of four broad-leaved tree species used to revegetate eroded granite hill slopes     

Kanae Ishimaru  Naoko Tokuchi  Naoya Osawa  Koji Kawamura  Hiroshi Takeda 《Journal of Forest Research》2005,10(1):27-34

Information on primary growth behavior after planting is required for mixed-plantation revegetation using broad-leaved species. To estimate primary growth, especially from the perspective of crown coverage and changing growth rates, we examined the growth and survival of four broad-leaved species that are frequently used in erosion-control plantations in Japan. The species studied were Myrica rubra Sieb. et Zucc., Alnus pendula Matsum., Quercus glauca Thunb., and Q. serrata Thunb. The survival, height, and basal diameter of planted trees were measured over a 4-year period, and crown area was calculated over a 3-year period. We found a negative relationship between relative growth rate (RGR) and survival rate, suggesting that fast growth may be fatal when resources are severely limited. The relative height growth rate (RHGR) of A. pendula was especially high during the early period of the study (1997–1999) and then drastically declined, whereas the opposite tendency was observed in Q. glauca. The results of stem allometry analyses conformed to the specific relationships between height growth and diameter growth of the four species; increases in stem thickness based on height increments were smaller in the pioneer species A. pendula. Between-species differences in coverage per planted tree (mean crown area multiplied by survival rate) were small as a result of the negative relationship between coverage area and survival rate.  相似文献