Is It Possible to Use 90Sr and 137Cs As Tracers for the Aeolian Dust Transport?     

Yasuhito Igarashi  Michio Aoyama  Katsumi Hirose  Takashi Miyao  Sadayo Yabuki 《Water, air, and soil pollution》2001,130(1-4):349-354

A noble approach for the estimation of the deposition of the Asian dust over Japan by using atmospheric anthropogenic radioactivity, ⁹⁰Sr and ¹³⁷Cs, is proposed. Those radioactivities once deposited globally onto the ground by the past nuclear test, etc. are resuspended along with the surface soil particles in the air by the storm and deposited again on the ground. The difference in ¹³⁷Cs/⁹⁰Sr activity ratios in the surface soil between dry and wet climatic conditions gives a clue to know about the source of the dust. It was found that the average activity ratio in the deposited material (average: 2.1, n=82) at MRI, Tsukuba in the 1990s is not close to that of the surface soil taken in neighborhood (median: 6.8, n=8), which had been considered as the primary source. While, it is close to that of the soil samples taken in the arid area in the Asian continent (median: 2.0, n=4), which is the one of the source regions of the aeolian dust. Thus we can reasonably assume that deposited dust in Tsukuba is brought not only from the neighboring fields, etc. but also from the arid area in the continent. Using a simple two-component model it was estimated that the Asian dust may transport about 90% of ⁹⁰Sr and 70% of ¹³⁷Cs depositions observed in Tsukuba in the 1990s. Also, Asian dust may transport about 2/3 of the dust deposited in Tsukuba.  相似文献   

Transcellular penetration of Treponema phagedenis isolated from papillomatous digital dermatitis in polarized normal human epidermal keratinocytes in vitro     

Rathanon KHEMGAEW  Mari OMACHI  Tomoe TAKESADA  Torrung VETCHAPITAK  Hiroyuki SATO  Takako TANIGUCHI  Naoaki MISAWA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(6):889

Papillomatous digital dermatitis (PDD) is a polymicrobial infection causing lameness in dairy cattle. Culture-independent analysis has shown that Treponema phagedenis is present consistently and predominantly in the lesions. However, the pathogenesis of PDD, especially the tissue penetration pathway, has not been examined. In the present study, we investigated whether T. phagedenis strains isolated from PDD produce proteolytic enzyme (s) for disruption of the epithelial cell barrier and have the ability to translocate in polarized normal human epidermal keratinocytes (NHEK) in vitro. Ten strains of T. phagedenis isolated from lesions did not show proteolytic activity on modified skim milk agar, although a human strain of T. denticola used as a control showed such activity. The integrity of tight junctions was monitored by measurement of transepithelial electrical resistance (TER). The TER values after inoculation of the T. phagedenis strains examined did not change during the experimental period; however, apical to basolateral translocation of T. phagedenis was confirmed after 24 hr by microscopy and Treponema-specific PCR. We further confirmed that translocation of T. phagedenis was accelerated by co-inoculation with live T. denticola, but not with heat-killed organisms. Furthermore, tight junction ZO-1 protein was not lost intensity after inoculation with T. phagedenis and the organism was observed in NHEK cells using a florescence microscope. These results suggest that T. phagedenis strains may translocate via a transcellular route in vitro and that the invasion is accelerated by other bacteria, such as T. denticola, producing proteolytic activity.  相似文献   

Diagnosis of equine piroplasmosis in Xinjiang province of China by the enzyme-linked immunosorbent assays using recombinant antigens   总被引：1，自引：0，他引：1  

Xuan X  Chahan B  Huang X  Yokoyama N  Makala LH  Igarashi I  Fujisaki K  Maruyama S  Sakai T  Mikami T 《Veterinary parasitology》2002,108(2):179-182

The prevalence of equine piroplasmosis in Xinjiang province, China, was examined by enzyme-linked immunosorbent assays (ELISAs). A total of 70 serum samples were taken from horses pastured on three farms in western Xinjiang, and examined for diagnosis of equine Babesia equi (B. equi) infection and B. caballi infection by ELISAs using recombinant equi merozoite antigen 1 (EMA-1) and recombinant P48 antigen, respectively. Of the 70 samples, 28 (40.0%) and 17 (24.3%) samples were positive for B. equi infection and B. caballi infection, respectively. In addition, 11 (15.7%) samples were positive for both B. equi and B. caballi infections. These results indicate that equine piroplasmosis is widespread and therefore a cause for serious concern in western Xinjiang. To our knowledge, this is the first report describing a survey on equine piroplasmosis in Xinjiang province, China.  相似文献   

The Genetic Diversity of Merozoite Surface Antigen 1 (MSA-1) among Babesia bovis Detected from Cattle Populations in Thailand,Brazil and Ghana     

Daisuke NAGANO  Thillaiampalam SIVAKUMAR  Alane Caine Costa DE DE MACEDO  Tawin INPANKAEW  Andy ALHASSAN  Ikuo IGARASHI  Naoaki YOKOYAMA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2013,75(11):1463-1470

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The ex vivo effects of eyestalk peptides on ovarian vitellogenin gene expression in the kuruma prawn Marsupenaeus japonicus     

Naoaki Tsutsui  Ayano Nagakura-Nakamura  Chiaki Nagai  Tsuyoshi Ohira  Marcy N. Wilder  Hiromichi Nagasawa 《Fisheries Science》2013,79(1):33-38

Seven major peptides belonging to the crustacean hyperglycemic hormone family were purified from the sinus gland located in the eyestalk of the kuruma prawn Marsupenaeus japonicus, and their effects on vitellogenin gene expression were examined using the ex vivo ovary incubation system. Six molecular species of crustacean hyperglycemic hormone, Pej-SGP-I, -II, -III, -V, VI, and VII, displayed significant inhibitory effects on vg expression with almost the same efficacies, whereas Pej-SGP-IV (known as molt-inhibiting hormone) did not. Two chromatophorotropic peptides, red pigment-concentrating hormone and pigment-dispersing hormone, which were also present in the sinus glands, did not have a clear effect on the gene expression levels in this incubation system. These results suggest that the six crustacean hyperglycemic hormones are potentially capable of acting as vitellogenesis-inhibiting hormones in M. japonicus.  相似文献   

Molecular cloning of a cDNA encoding vitellogenesis-inhibiting hormone in the whiteleg shrimp Litopenaeus vannamei and preparation of its recombinant peptide using an E. coli expression system     

Naoaki Tsutsui  Tsuyoshi Ohira  Tomoyuki Okutsu  Junpei Shinji  Sun-Hye Bae  Bong Jung Kang  Marcy N. Wilder 《Fisheries Science》2013,79(3):357-365

The cDNA encoding a precursor of Liv-SGP-G, the most abundant crustacean hyperglycemic hormone-family peptide in the sinus gland of the whiteleg shrimp Litopenaeus vannamei, was cloned by RT-PCR coupled with 5′- and 3′-RACE. The determined cDNA sequence consisted of 621 nucleotides comprising a 69-bp 5′-untranslated region, a 357-bp open reading frame, and a 195-bp 3′-untranslated region. The deduced sequence of 72 amino acid residues corresponding to mature Liv-SGP-G was completely identical to that of natural Liv-SGP-G, determined in our previous study. The recombinant Liv-SGP-G was thereafter heterologously expressed in Escherichia coli, and its vitellogenesis-inhibiting activity in ex vivo cultured ovarian fragments was examined. The recombinant peptides inhibited vitellogenin gene expression with almost the same efficacy as that of natural Liv-SGP-G purified from sinus glands.  相似文献   

Pharmacokinetics of fentanyl after single intravenous injection and constant rate infusion in dogs     

Sano T  Nishimura R  Kanazawa H  Igarashi E  Nagata Y  Mochizuki M  Sasaki N 《Veterinary anaesthesia and analgesia》2006,33(4):266-273

OBJECTIVE: To determine the plasma concentration and define the pharmacokinetic characteristics of fentanyl (10 microg kg(-1)) administered as a single intravenous (IV) injection followed by: (a) no further drug; or (b) a constant rate infusion (CRI) of fentanyl 10 microg kg(-1) hour(-1) lasting 1, 3 or 4 hours in dogs. Animals Fourteen healthy adult beagles (seven males and seven females). EXPERIMENTAL DESIGN: Randomized cross-over design. MATERIALS AND METHODS: Dogs were randomly assigned to four treatment groups. Drugs were administered to each dog in a randomized cross-over design with at least a 14-day washout interval between experiments. All dogs received an IV loading dose of fentanyl (10 microg kg(-1)). One group received no further fentanyl. In others, the loading dose was followed by a CRI of fentanyl (10 microg kg(-1) hour(-1)) for 1, 3 or 4 hours. Blood samples were collected and plasma fentanyl concentrations determined using high-performance liquid chromatography-mass spectrometry. Plasma pharmacokinetic estimates were obtained by plotting plasma concentrations versus time data and by fitting the change in concentration to a pharmacokinetic model, using a purpose-built program written by the Graduate School of Pharmaceutical Sciences (Kyoto University) in Visual Basic (VBA) on Excel (Microsoft Corporation). RESULTS: Plasma fentanyl concentration decreased rapidly after single IV injection: the plasma concentration-time curve best fitted a two-compartment model. Pharmacokinetic variables for IV injection were characterized by a short distribution half-time (t1/2alpha was 4.5 minutes), a relatively long elimination half time (t1/2beta was 45.7 minutes), a large volume of distribution (approximately 5 L kg(-1)) and high total body clearance (77.9 mL minute(-1) kg(-1)). Stable plasma fentanyl levels were obtained in all CRI groups although pharmacokinetic variables were influenced by the duration of administration. CONCLUSIONS AND CLINICAL RELEVANCE: While this study clarified the pharmacokinetic features of rapid IV fentanyl injection and CRI in dogs, the plasma concentration achieving analgesia was not and so further research is needed. Further studies on the effects of other sedatives and/or anaesthetics on fentanyl's disposition are also required as the drug is commonly used with other agents.  相似文献   

The potential of hinoki (Chamaecyparis obtusa [Sieb. et Zucc.] Endlicher) plantation forests for the restoration of the original plant community in Japan     

Tetsuya Igarashi  Yoshiyuki Kiyono 《Forest Ecology and Management》2008

We estimated the potential of plantation forests for the restoration of the original plant community. We compared the understory vegetation in hinoki (Chamaecyparis obtusa [Sieb. et Zucc.] Endlicher) plantations at the understory re-initiation stage and in adjacent natural forests. To estimate the effect of the original natural forests on the understory species composition of plantation forests, we established study sites in five types of natural forests (mature evergreen broadleaf, mature deciduous broadleaf, mature evergreen coniferous, immature deciduous broadleaf warm-temperate, and immature deciduous broadleaf cool-temperate) and nearby plantation forests. The understory vegetation of the plantation forests had a higher species richness, a higher proportion of early-seral species, and a higher proportion of herb or fern species than the natural forests. The differences between natural and plantation forests varied according to the species composition of the natural forests. The composition of the understory vegetation of the plantations at the understory re-initiation stage was similar to that of the immature deciduous forests. The characteristics of immature, disturbed forests remained in the understory vegetation of the hinoki forests. No great loss of species was observed. Our findings suggest that most of the original forest species still survive in the understory of the plantation forests. These forests have the potential to follow the successional pathway to broadleaf or mixed forests via thinning or clear-cutting without planting.  相似文献   

Oceanographic factors affecting interannual recruitment variability of Pacific saury (Cololabis saira) in the central and western North Pacific          下载免费PDF全文

Taro Ichii  Haruka Nishikawa  Kedarnath Mahapatra  Hiroshi Okamura  Hiromichi Igarashi  Mitsuo Sakai  Satoshi Suyama  Masayasu Nakagami  Miyako Naya  Norihisa Usui  Yoshihiro Okada 《Fisheries Oceanography》2018,27(5):445-457

Pacific saury (Cololabis saira) has a short life span of 2 years and tends to exhibit marked population fluctuations. To examine the importance of sea surface temperature (SST) and mixed layer depth (MLD) as oceanographic factors for interannual variability of saury recruitment in early life history, we analyzed the relationship between abundance index (survey CPUE (catch per unit of effort)) of age‐1 fish and the oceanographic factors in the spawning and nursery grounds of the previous year when they were born, for the period of 1979–2006, in the central and western North Pacific. Applying the mixture of two linear regression models, the variability in the survey CPUE was positively correlated with previous year's winter SST in the Kuroshio Recirculation region (KR) throughout the survey period except 1994–2002. In contrast, the survey CPUE was positively correlated with the previous year's spring MLD (a proxy of spring chlorophyll a (Chl‐a) concentration) in the Kuroshio‐Oyashio Transition and Kuroshio Extension (TKE) during 1994–2002. This period is characterized by unusually deep spring MLD during 1994–1997 and anomalous climate conditions during 1998–2002. We suggest that saury recruitment variability was generally driven by the winter SST in the KR (winter spawning/nursery ground), or by the spring Chl‐a concentration (a proxy of prey for saury larvae) in the TKE (spring spawning/nursery ground). These oceanographic factors could be potentially useful to predict abundance trends of age‐1 saury in the future if the conditions leading to the switch between SST and MLD as the key input variable are elucidated further.  相似文献   

Presence of contagious yawning in sheep          下载免费PDF全文

Tomohiro Yonezawa  Kohei Sato  Mona Uchida  Naoaki Matsuki  Atusi Yamazaki 《Animal Science Journal》2017,88(1):195-200

Contagious yawning is triggered by others yawning, and it has previously been reported in humans, primates and several experimental and companion mammals. Whereas it might be a response to an innate releasing mechanism, contagious yawning is also considered to involve emotional contagion. Here, we demonstrate that sheep, the animal model of livestock animals, also experience contagious yawning. Twelve adult castrated Corriedale sheep were used in this study. Pairs of sheep were adjacently restrained with or without a wooden divider panel to shield them from viewing the other. Their behaviors were video‐recorded for 3 days in each condition. Sheep yawned 2.0 ± 1.1 and 1.2 ± 1.1 times/day/head in the unshielded and shielded conditions, respectively. Unshielded restrained sheep yawned within 1 min after the other one 11.1% of the time, while shielded pairs did not exhibit contagious yawning. Rumination was also highly synchronized under the unshielded condition. These data reveal that contagious yawning and behavioral synchronicity occur in ruminants like sheep, making them a suitable animal model to investigate contagious yawning and the underlying mechanism.  相似文献