Net depth response of a depth-controllable (towed) gillnet for fish sampling     

Daisuke Shiode  Yasuzumi Fujimori  Fuxiang Hu  Susumu Shimizu  Teisuke Miura 《Fisheries Science》2001,67(1):110-117

SUMMARY: Flume-tank experiments were performed to examine the depth response of a new type of depth-controlled gillnet. Variations of net depth were investigated as the warp was paid out and wound up for different changes of warp length, main sinker weights, and winch speeds. In most experiments, when the warp finished paying out, the net continued to descend and then ascended slightly to an equilibrium depth (overshoot phenomenon). The overshoot distance was nearly constant when the warp was wound up and increased linearly with increasing winch speed when the warp was paid out. An increase in winch speed reduced net settling time, which converged on a constant value for both paying out and winding up.  相似文献   

Hemagglutination and hemagglutination inhibition with Chuzan virus.     

Y Goto  Y Miura  Y Kono 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1991,53(1):29-32

Chuzan virus agglutinated erythrocytes of several species of animals including bovine. The hemagglutinating (HA) activity against bovine erythrocytes was dependent on NaCl molarity and was expressed best at 0.6 M, but it was independent of pH and temperature. Three strains of Chuzan virus isolated from 2 cows and a pool of culicoides midges had indistinguishable HA antigenicity. All cattle infected with the virus developed high titers of hemagglutination inhibiting (HI) antibody which changed in parallel with neutralizing (NT) antibody titers. Correlation between HI and NT antibodies was very high and the antibodies persisted for one year or more. Therefore it was concluded that the HI test is applicable for survey of Chuzan virus infection among cattle in place of the NT test.  相似文献   

Comparison of intraoperative cardiorespiratory and behavioral responses to medetomidine combined with tramadol or butorphanol during standing laparoscopic ovariectomy in horses     

Ahram KIM  Naoki SASAKI  Inhyung LEE  Jong-pil SEO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(4):643

The purpose of this study was to assess the cardiorespiratory and behavioral responses to the combination of medetomidine and tramadol (M-T) or butorphanol (M-B) in standing laparoscopic ovariectomy in horses. One ovary was removed under M-T and the contralateral ovary was removed under M-B with at least 4 weeks between operations at random. Horses were sedated using intravenous medetomidine (5 µg/kg) followed by tramadol (1 mg/kg) or butorphanol (10 µg/kg) after 5 min. Sedation was maintained through the repeated injection of medetomidine (1 µg/kg) and tramadol (0.4 mg/kg) or medetomidine (1 µg/kg) and butorphanol (4 µg/kg) every 15 min. Cardiorespiratory function and behavioral responses, including, sedation, ataxia, and analgesia, were assessed during the surgery. There were no significant differences in cardiorespiratory values and sedation and analgesia scores between M-T and M-B. Ataxia scores were significantly lower in M-T than in M-B. This result suggests that M-T could maintain smooth and stable standing surgery with minimal cardiorespiratory changes in horses.  相似文献   

Comparison of N-terminal pro-atrial natriuretic peptide and three cardiac biomarkers for discriminatory ability of clinical stage in dogs with myxomatous mitral valve disease     

Mizuki OGAWA  Yasutomo HORI  Nobuyuki KANNO  Naoki IWASA  Takeshi TOYOFUKU  Noriko ISAYAMA  Akane YOSHIKAWA  Ryota AKABANE  Atsushi SAKATANI  Hirosumi MIYAKAWA  Huai-Hsun HSU  Yuichi MIYAGAWA  Naoyuki TAKEMURA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(4):705

Plasma N-terminal pro-atrial natriuretic peptide (NT-proANP) concentration increases with progression of myxomatous mitral valve disease (MMVD) in dogs. This multicentre, prospective study compared plasma NT-proANP, N-terminal pro-brain natriuretic peptide (NT-proBNP), ANP, and cardiac troponin I (cTnI) concentrations in dogs with MMVD for their characteristics and discriminatory ability to detect cardiac dilatation and congestive heart failure (CHF). Thirty-six healthy dogs and 69 dogs with MMVD were included. Clinical variables were obtained via physical examination, thoracic radiography, and echocardiography. The discriminatory ability of each cardiac biomarker (CB) to determine the presence or absence of cardiac dilatation (event 1) and CHF (event 2) was evaluated using the receiver operating characteristic curves. Plasma NT-proANP, NT-proBNP, and ANP concentrations showed a significant association with the left atrium/aorta ratio (P<0.01). The area under the curve of plasma NT-proANP and NT-proBNP concentrations were 0.72 and 0.75, respectively in event1 and 0.72 and 0.76, respectively in event2. Plasma NT-proANP and NT-proBNP concentrations showed sensitivity 80.0 and 80.0%; specificity 67.6 and 64.7% in event1 (cutoff value; 8,497.81 pg/ml and 1,453.00 pmol/l, respectively) and sensitivity 85.7 and 81.0%; specificity 60.4 and 64.6% in event2 (cutoff value; 8,684.33 pg/ml and 1,772.00 pmol/l, respectively). In dogs with MMVD, plasma NT-proANP, NT-proBNP, and ANP concentrations increase with left atrial enlargement. Particularly, plasma NT-proANP and NT-proBNP concentrations appeared to be equally useful in the discriminatory ability to detect cardiac dilatation and CHF.  相似文献   

Identification of the core rumen bacterial taxa and their population dynamics during the fattening period in Japanese Black cattle     

Hiroto Miura  Takuya Hashimoto  Yukiko Kawanishi  Hiroki Kawauchi  Ryo Inoue  Noriaki Shoji  Kunihiko Saito  Mario Sekiya  Yosuke Saito  Jumpei Yasuda  Chiemi Yonezawa  Tetsushiro Endo  Hirotaka Kasuya  Yutaka Suzuki  Yasuo Kobayashi  Satoshi Koike 《Animal Science Journal》2021,92(1):e13601

The rumen microbiota comprises a vast range of bacterial taxa, which may affect the production of high-quality meat in Japanese Black cattle. The aim of this study was to identify core rumen microbiota in rumen fluid samples collected from 74 Japanese Black cattle raised under different dietary conditions using 16S rRNA gene amplicon sequencing. In the rumen of fattening Japanese Black cattle, 10 bacterial taxa, showing >1% average relative abundance and >95% prevalence, irrespective of the dietary conditions and the fattening periods, were identified as the core rumen bacterial taxa, which accounted for approximately 80% of the rumen microbiota in Japanese Black cattle. Additionally, population dynamics of the core rumen bacterial taxa revealed two distinct patterns: Prevotella spp. and unclassified Bacteroidales decreased in the mid-fattening period, whereas unclassified Clostridiales, unclassified Ruminococcaceae, Ruminococcus spp., and unclassified Christensenellaceae increased during the same period. Therefore, the present study reports the wide distribution of the core rumen bacterial taxa in Japanese Black cattle, and the complementary nature of the population dynamics of these core taxa, which may ensure stable rumen fermentation during the fattening period.  相似文献   

Changes in the expression of toll-like receptor mRNAs during follicular growth and in response to lipopolysaccharide in the ovarian follicles of laying hens     

Subedi K  Isobe N  Nishibori M  Yoshimura Y 《The Journal of reproduction and development》2007,53(6):1227-1235

The aim of this study was to determine the changes in the mRNA expression of Toll-like receptors (TLRs) in hen ovarian follicles during follicular growth and in response to lipopolysaccharide (LPS). White follicles and the fifth largest to largest follicles (WF and F(5)-F(1), respectively) were collected from laying hens. To examine the effects of LPS, the laying hens were treated intravenously with LPS (1 mg/kg BW) 0, 3, 6, 12 and 24 h before examination. Expressions of TLRs and IL-1beta in the theca and granulosa layers were examined by semi-quantitative RT-PCR. Immunocytochemistry was performed to identify immunoreactive TLR-4. The theca layer expressed TLR-2, TLR-4, TLR-5 and TLR-7, whereas the granulosa layer expressed only TLR-4 and TLR-5. The expression of TLR-4 and TLR-5 in the theca layer increased significantly during follicular growth. In the granulosa layer, the expression of TLR-5 increased, but that of TLR-4 was unchanged. Expression of TLR-4 increased significantly during the period of 6 to 12 h of LPS treatment in the theca layer and during the period of 12 to 24 h in the granulosa layer of F(3). Immunoreaction products for TLR-4 were observed in theca interna and granulosa layers of WF and F(5)-F(1), with the greater amount observed in the theca interna. LPS treatment significantly increased expression of IL-1beta in the theca layer after 3 h and in the granulosa layer during the period of 12 to 24 h. These results suggest that TLRs are expressed in ovarian follicles and that TLR-4 and TLR-5 expression increase with the growth of follicles. Enhanced expression of TLR-4 and IL-1beta by LPS in the theca and granulosa layers suggests possible roles of TLR in recognition of microorganisms.  相似文献   

Production of novel alloplasmic male sterile lines in Allium cepa harbouring the cytoplasm from Allium roylei     

Hao Q. Vu  Machiko Iwata  Naoki Yamauchi  Masayoshi Shigyo 《Plant Breeding》2011,130(4):469-475

  相似文献   

Influences of indigenous phototrophs on methane emissions from a straw-amended paddy soil     

Naoki Harada  Shigeto Otsuka  Masaya Nishiyama  Satoshi Matsumoto 《Biology and Fertility of Soils》2005,41(1):46-51

A pot experiment was conducted to investigate the influences of indigenous phototrophs on methane (CH₄) emissions from a paddy soil where rice straw was incorporated or was surface-applied. During the cultivation, half of the pots were covered with aluminum foil, except for the minimum space for rice plants, to prevent ambient light reaching the floodwater or the soil surface. Growth of oxygen-producing phototrophs was hardly observed in the unilluminated plots, whereas intensive growth of algae, duckweed and hydrophytes was found in the illuminated ones. Plant growth was not affected by the different treatments. Seasonal changes in CH₄ emission determined by a closed chamber method indicated that illumination had no or only minor effects on CH₄ emissions when rice straw was incorporated or was not applied, but significantly reduced CH₄ emissions when rice straw was surface-applied. Methanogenesis occurring in the soil-floodwater interface was further investigated in two lab-scale model experiments measuring methanogenic activity. As a result, more activated methanogenesis was found in the surface-applied rice straw and the soil around the straw compared with the soil incubated without rice straw. The magnitude of the methanogenic activity in the rice straw incubated under illuminated conditions was significantly lower than that incubated in the dark. Consequently, this study demonstrates that methanogenesis in paddy soil occurs even in the soil-floodwater interface if plant residues like rice straw exist, and such methanogenesis is likely to be suppressed by growth of indigenous phototrophs under illumination.  相似文献   

Regression tree analysis of the relationship between the concentrations of antimicrobial components and the microbiota of normal milk from dairy cows     

Yasunori SHINOZUKA  Naoki SUZUKI  Sohei KANEKO  Kazuhiro KAWAI  Tomomi KURUMISAWA  Yuko SHIMIZU  Tadashi IMANISHI  Ayumu OHNO  Mano TAKAHASHI  Naoki ISOBE 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2022,84(3):310

The purpose of this study was to determine the concentrations of antimicrobial components (immunoglobulin A (IgA), lactoferrin (LF), lingual antimicrobial peptide (LAP), and S100A7) in normal milk and their relation to host factors (Age, somatic cell count (SCC), days in milk, richness, and alpha diversity of the milk microbiota) in dairy cows using multivariate regression tree analyses, and to clarify how the milk microbiota is related to the obtained results. Thirty normal milk samples were collected from a commercial dairy farm in June 2020. The thresholds that predicted the concentration of each antimicrobial component in milk were obtained by regression tree analysis, and the beta-diversity of the milk microbiota composition between groups divided according to each threshold was compared by an analysis of similarities test. The IgA and LF concentrations were mainly predicted by the SCC (177,500 and 70,000 cells/ml, respectively), and the LAP and S100A7 concentrations were predicted by Age (29.667 and 40.3 months, respectively). No relationship was observed between the concentration of IgA, LAP, or S100A7 and the milk microbiota composition between the groups divided by the threshold for prediction, but the milk microbiota composition was significantly different between the groups divided by the threshold for predicting the LF concentration. Our results indicated that the LF concentration in normal milk may be associated with the milk microbiota composition.  相似文献   

Spermatogenesis and its endocrine regulation   总被引：2，自引：2，他引：2  

Rüdiger W. Schulz  Takeshi Miura 《Fish physiology and biochemistry》2002,26(1):43-56

Three major phases compose spermatogenesis: mitotic proliferation of spermatogonia, meiosis of spermatocytes, and spermiogenesis, the restructuring of spermatids into flagellated spermatozoa. The process is fuelled by stem cells that, when dividing, either self-renew or produce spermatogonia that are committed to proliferation, meiosis, and spermiogenesis. During all phases, germ cells are in close contact with and require the structural and functional support of Sertoli cells. In contrast to germ cells, these somatic cells express receptors for sex steroids and follicle-stimulating hormone (FSH), the most important hormones that regulate spermatogenesis. A typical Sertoli cell response to an endocrine stimulus would be to change the release of a growth factor that would then mediate the hormone's effect to the germ cells. Recent studies in the Japanese eel have shown, for example, that in the absence of gonadotropin Sertoli cells produce a growth factor (an orthologue of anti-Müllerian hormone) that restricts stem cell divisions to the self-renewal pathway; also estrogens stimulate stem cell renewal divisions but not spermatogonial proliferation. Gonadotropin or 11-ketotestosterone (11-KT) stimulation, however, induces spermatogonial proliferation, which is in part mimicked by another Sertoli cell-derived growth factor (activin B). Since FSH (besides luteinizing hormone, LH) stimulates steroidogenesis in fish, and since FSH is the only gonadotropin detected in the plasma of sexually immature salmonids, increased FSH signalling may be sufficient to initiate spermatogenesis by activating both Sertoli cell functions and 11-KT production. Another important androgen is testosterone (T), which seems to act via feedback mechanisms that can compromise FSH-dependent signalling or steroidogenesis. The testicular production of T and 11-KT therefore needs to be balanced adequately. Further research is required to elucidate in what way(s) 11-KT stimulates later stages of development, such as entry into meiosis and spermiogenesis. At this period, LH becomes increasingly important for the regulation of androgen production. Results from mammalian models suggest that during the later phases, the control of germ cell apoptosis via Sertoli cell factors is an important regulatory mechanism. In many species, sperm cells cannot fertilize eggs until having passed a maturation process known as capacitation, which includes the acquisition of motility. Progestins that are produced under the influence of LH appear to play an important role in this context, which involves the control of the composition of the seminal plasma (e.g., pH values). This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献