677 research outputs found

    Fish assemblages associated with three types of artificial reefs: density of assemblages and possible impacts on adjacent fish abundance

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    We evaluated the effectiveness of wooden artificial reefs (ARs) as fish habitat. Three types of ARs, made of cedar logs, broadleaf tree logs, and PVC pipes, respectively, were deployed in triplicate at 8-m depth off Maizuru, Kyoto Prefecture, Sea of Japan, in May 2004. Fish assemblages associated with each of the nine ARs were observed by using SCUBA twice a month for four years. Fish assemblages in the adjacent habitat were also monitored for two years before and four years after reef deployment. In the surveyed areas (ca. 10 m2) associated with each of the cedar, broadleaf, and PVC ARs, the average number of fish species was 4.14, 3.49, and 3.00, and the average number of individuals was 40.7, 27.9, and 20.3, respectively. The estimated biomass was also more greater when associated with the cedar ARs than with other ARs. Visual censuses of the habitat adjacent to the ARs revealed that the number of fish species and the density of individuals were not affected by the deployment of the ARs. Our results support the superiority of cedar as an AR material and indicate that deployment of wooden ARs causes no reduction of fish abundance in adjacent natural reefs

    Water temperature and precipitation stimulate small-sized Japanese eels to climb a low-height vertical weir

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    Although river-crossing structures can have a detrimental effect on the movement and distribution of anguillid eels (genus Anguilla), they have inhabited locations upstream of river-crossing structures in many rivers. However, the growth stage in which the eels start to climb river-crossing structures remains unclear. In this study, we directly observed, using infrared video camera systems, that the Japanese eel (Anguilla japonica) climbs a low-height vertical weir as a migratory barrier, confirming the ability of eels to climb over a low-height weir within a river. All eels climbed the weir at night, between sunset and sunrise. We observed that the total length of Japanese eels that climbed the weir ranged from 60 to 140 mm, suggesting that eels inhabiting the upstream area of a weir climbed it when they were small and then lived and grew upstream. Moreover, the general additive model showed considerable effects of water temperature and precipitation on eel climbing, suggesting that water temperature and precipitation are important for its activation. The results of this study also show the effectiveness of infrared video cameras in monitoring eel climbing, which could be applied to monitor fish migratory behavior through fish passages. The findings of this study are useful for the comprehensive management and conservation of wild eel stocks

    Environmental DNA preserved in marine sediment for detecting jellyfish blooms after a tsunami

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    堆積物の環境DNAで探る過去の出来事 --津波直後のクラゲ大発生を検知--. 京都大学プレスリリース. 2021-08-23.Environmental DNA (eDNA) can be a powerful tool for detecting the distribution and abundance of target species. This study aimed to test the longevity of eDNA in marine sediment through a tank experiment and to use this information to reconstruct past faunal occurrence. In the tank experiment, juvenile jack mackerel (Trachurus japonicus) were kept in flow-through tanks with marine sediment for two weeks. Water and sediment samples from the tanks were collected after the removal of fish. In the field trial, sediment cores were collected in Moune Bay, northeast Japan, where unusual blooms of jellyfish (Aurelia sp.) occurred after a tsunami. The samples were analyzed by layers to detect the eDNA of jellyfish. The tank experiment revealed that after fish were removed, eDNA was not present in the water the next day, or subsequently, whereas eDNA was detectable in the sediment for 12 months. In the sediment core samples, jellyfish eDNA was detected at high concentrations above the layer with the highest content of polycyclic aromatic hydrocarbons, reflecting tsunami-induced oil spills. Thus, marine sediment eDNA preserves a record of target species for at least one year and can be used to reconstruct past faunal occurrence

    Oncostatin M renders epithelial cell adhesion molecule-positive liver cancer stem cells sensitive to 5-fluorouracil by inducing hepatocytic differentiation

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    金沢大学附属病院消化器内科Recent evidence suggests that a certain type of hepatocellular carcinoma (HCC) is hierarchically organized by a subset of cells with stem cell features (cancer stem cells; CSC). Although normal stem cells and CSCs are considered to share similar self-renewal programs, it remains unclear whether differentiation programs are also maintained in CSCs and effectively used for tumor eradication. In this study, we investigated the effect of oncostatin M (OSM), an interleukin 6-related cytokine known to induce the differentiation of hepatoblasts into hepatocytes, on liver CSCs. OSM receptor expression was detected in the majority of epithelial cell adhesion molecule-positive (EpCAM+) HCC with stem/progenitor cell features. OSM treatment resulted in the induction of hepatocytic differentiation of EpCAM+ HCC cells by inducing signal transducer and activator of transcription 3 activation, as determined by a decrease in stemness-related gene expression, a decrease in EpCAM, α-fetoprotein and cytokeratin 19 protein expressions, and an increase in albumin protein expression. OSM-treated EpCAM+ HCC cells showed enhanced cell proliferation with expansion of the EpCAM-negative non-CSC population. Noticeably, combination of OSM treatment with the chemotherapeutic agent 5-fluorouracil (5-FU), which eradicates EpCAM-negative non-CSCs, dramatically increased the number of apoptotic cells in vitro and suppressed tumor growth in vivo compared with either saline control, OSM, or 5-FU treatment alone. Taken together, our data suggest that OSM could be effectively used for the differentiation and active cell division of dormant EpCAM+ liver CSCs, and the combination of OSM and conventional chemotherapy with 5-FU efficiently eliminates HCC by targeting both CSCs and non-CSCs. ©2010 AACR

    Distribution of Japanese Eel Anguilla japonica Revealed by Environmental DNA

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    絶滅危惧種ニホンウナギの分布域を環境DNA解析で推定. 京都大学プレスリリース. 2021-03-03.The abundance of Japanese eel Anguilla japonica has rapidly decreased in recent decades. Following a re-evaluation of the possibility of extinction, the Japanese Ministry of the Environment and the International Union for Conservation of Nature listed the Japanese eel as an endangered species in 2013 and 2014, respectively. However, their abundance and precise distribution have never been clarified owing to their nocturnality and difficulty in their capture. In this study, the distribution of Japanese eels was investigated by monitoring for environmental DNA (eDNA), a non-invasive and efficient detection method. A total of 365 water samples were collected from 265 rivers located throughout Japan. High concentrations of eDNA of Japanese eels were detected in rivers on the Pacific side, but were low in the Sea of Japan side. In particular, very little eDNA amplification was confirmed from Hokkaido and the north of the Sea of Japan. The eDNA distribution in Japanese rivers coincides with the transport of the larvae in the ocean, as estimated by numerical simulations. Generalized linear mixed models were developed to explain the distribution of eDNA concentrations. The total nitrogen concentration emerged as an important factor in the best model. These results indicate that the distribution of Japanese eel is mostly determined by the maritime larval transport, and their survival and growth depend on the abundance of food in the river. The findings of the present study are useful for the management of populations and in the conservation of Japanese eels

    Combined chemotherapy with carboplatin plus irinotecan showed favorable efficacy in a patient with relapsed small cell carcinoma of the prostate complicated with meningeal carcinomatosis

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    金沢大学附属病院がん高度先進治療センター金沢大学がん研究所分子標的がん医療研究開発センターWe report the case of a 65-year-old man with recurrent prostate cancer who presented with meningeal carcinomatosis. In September 2007, he had been diagnosed with mixed type small cell carcinoma and adenocarcinoma at clinical stage T4N1M1 (primary prostate tumor with multiple bone, liver, and lymph node metastases) and hormonal therapy had been administered. Following an increase in the level of pro-gastrin-releasing peptide (ProGRP), combined chemotherapy with cisplatin plus etoposide was implemented and showed efficacy in targeting the small cell carcinoma. In March 2008, he presented with signs of meningeal irritation; his condition deteriorated quickly and multiple brain metastases were confirmed by magnetic resonance imaging (MRI). A sample of cerebrospinal fluid collected by lumbar puncture showed cancer cells and an elevated level of ProGRP. Small cell carcinoma of the prostate complicated with meningeal carcinomatosis was diagnosed. A different chemotherapy regimen was then administered, consisting of a combination of carboplatin plus irinotecan, which is one of the most common first-line treatments for extensive-stage small cell lung carcinoma. From day 20 after the initiation of this therapy, he gradually recovered from the signs of meningeal irritation, and brain MRI showed nearly normal findings; also, the serum level of ProGRP was reduced. In conclusion, we report the efficacy of combined treatment with carboplatin plus irinotecan for small cell carcinoma of the prostate complicated with meningeal carcinomatosis. Because this clinical condition is extremely rare, a gold standard treatment has yet to be established. © 2009 Japan Society of Clinical Oncology

    Measurement of the Dipion Mass Spectrum in X(3872) -> J/Psi Pi+ Pi- Decays

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    We measure the dipion mass spectrum in X(3872)--> J/Psi Pi+ Pi- decays using 360 pb-1 of pbar-p collisions at 1.96 TeV collected with the CDF II detector. The spectrum is fit with predictions for odd C-parity (3S1, 1P1, and 3DJ) charmonia decaying to J/Psi Pi+ Pi-, as well as even C-parity states in which the pions are from Rho0 decay. The latter case also encompasses exotic interpretations, such as a D0-D*0Bar molecule. Only the 3S1 and J/Psi Rho hypotheses are compatible with our data. Since 3S1 is untenable on other grounds, decay via J/Psi Rho is favored, which implies C=+1 for the X(3872). Models for different J/Psi-Rho angular momenta L are considered. Flexibility in the models, especially the introduction of Rho-Omega interference, enable good descriptions of our data for both L=0 and 1.Comment: 7 pages, 4 figures -- Submitted to Phys. Rev. Let

    Search for Pair Production of Scalar Top Quarks Decaying to a tau Lepton and a b Quark in ppbar Collisions at sqrt{s}=1.96 TeV

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    We search for pair production of supersymmetric top quarks (~t_1), followed by R-parity violating decay ~t_1 -> tau b with a branching ratio beta, using 322 pb^-1 of ppbar collisions at sqrt{s}=1.96 TeV collected by the CDF II detector at Fermilab. Two candidate events pass our final selection criteria, consistent with the standard model expectation. We set upper limits on the cross section sigma(~t_1 ~tbar_1)*beta^2 as a function of the stop mass m(~t_1). Assuming beta=1, we set a 95% confidence level limit m(~t_1)>153 GeV/c^2. The limits are also applicable to the case of a third generation scalar leptoquark (LQ_3) decaying LQ_3 -> tau b.Comment: 7 pages, 2 eps figure

    Search for Higgs Boson Decaying to b-bbar and Produced in Association with W Bosons in p-pbar Collisions at sqrt{s}=1.96 TeV

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    We present a search for Higgs bosons decaying into b-bbar and produced in association with W bosons in p-pbar collisions at sqrt{s}=1.96 TeV. This search uses 320 pb-1 of the dataset accumulated by the upgraded Collider Detector at Fermilab. Events are selected that have a high-transverse momentum electron or muon, missing transverse energy, and two jets, one of which is consistent with a hadronization of a b quark. Both the number of events and the dijet mass distribution are consistent with standard model background expectations, and we set 95% confidence level upper limits on the production cross section times branching ratio for the Higgs boson or any new particle with similar decay kinematics. These upper limits range from 10 pb for mH=110 GeV/c2 to 3 pb for mH=150 GeV/c2.Comment: 7 pages, 3 figures; updated title to published versio

    Search for Second-Generation Scalar Leptoquarks in ppˉ\bm{p \bar{p}} Collisions at s\sqrt{s}=1.96 TeV

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    Results on a search for pair production of second generation scalar leptoquark in ppˉp \bar{p} collisions at s\sqrt{s}=1.96 TeV are reported. The data analyzed were collected by the CDF detector during the 2002-2003 Tevatron Run II and correspond to an integrated luminosity of 198 pb1^{-1}. Leptoquarks (LQ) are sought through their decay into (charged) leptons and quarks, with final state signatures represented by two muons and jets and one muon, large transverse missing energy and jets. We observe no evidence for LQLQ production and derive 95% C.L. upper limits on the LQLQ production cross sections as well as lower limits on their mass as a function of β\beta, where β\beta is the branching fraction for LQμqLQ \to \mu q.Comment: 9 pages (3 author list) 5 figure
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