• Title/Summary/Keyword: ZEBRA

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Antagonism of Bacterial Extracellular Metabolites to Freshwater-Fouling Invertebrate Zebra Mussels, Dreissena polymopha

  • Gu, Ji-Dong;Ralph Mitchell
    • Journal of Microbiology
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    • v.39 no.2
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    • pp.133-138
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    • 2001
  • We investigated the antagonism of indigenous bacteria isolated from stressed mussels and their extracellular metabolites on the adult zebra mussel, Dreissena polymorpha. Selective bacterial isolates including Aeromonas media, A. salmonicida, A. veronii, and Shewanella putrefaciens, showed strong lethality against adult mussels and 100% mortality was observed within 5 days of incubation. Bacterial metabolites, fractionated and concentrated from stationary-phase culture supernatants of these bacterial isolates, displayed varying degrees of antagonistic effects on zebra mussels. Among the three size fractions examined, <5, 5-10, and >10 kDa, the mast lethal fraction seems to be >10 kDa for three of the four isolates tested. Further chemical analyses of these size fractions revealed that the predominant constituents were polysaccharides and proteins. No 2-keto-3-deoxyoctanoic acid (2-KDO), deoxyribonucleic acids (DNA) or uranic acid were detectable. Extraction of supernatants of two antagonistic isolates with polar solvent suggested that polar molecules are present in the active fraction. Our data suggest that extracellular metabolites produced by antagonistic bacteria are also involved in disease development in zebra mussels and elucidation of the mechanisms involved may offer a novel strategy for control of biofouling invertebrates.

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Isolation of Photobacterium damselae subsp. damselae from zebra shark Stegostoma fasciatum

  • Han, Jee Eun;Gomez, Dennis K.;Kim, Ji Hyung;Choresca, Casiano H. Jr.;Shin, Sang Phil;Baeck, Gun Wook;Park, Se Chang
    • Korean Journal of Veterinary Research
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    • v.49 no.1
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    • pp.35-38
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    • 2009
  • The zebra shark Stegostoma fasciatum which had been reared in the commercial aquaria was found dead and submitted for postmortem examination. A pure bacterial culture was isolated from pale and enlarged liver. The analysis of ureC and 16S rRNA genes confirmed the isolate as Photobacterium (P.) damselae subsp. damselae and this pathogen was sensitive to gentamicin. Although, no mortality in mouse was observed in the experimental infection study, the isolation of this pathogen in aquarium fish is significant because it can act as a reservoir to other aquatic animals and can also be zoonotic potential to human during aquarium management. This paper describes the first isolation of P. damselae subsp. damselae from zebra shark.

A Case of Ascarid Impaction and Intestinal Perforation in an Adult Zebra (Equus burchelli bohmi) (성숙한 얼룩말에서 Ascarid Impaction 및 장천공)

  • Yang, Jae-Hyuk;Lim, Yoon-Kyu
    • Journal of Veterinary Clinics
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    • v.28 no.4
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    • pp.442-445
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    • 2011
  • Macrocyclic lactone resistance has been reported in populations of Parascaris equorum from several countries. A Grant's zebra (Equus burchelli bohmi) was admitted to the Equine Hospital at Jeju Race Park with signs of chronic weight loss and severe depression. Clinical examination revealed tachycardia and dehydration. Over the course of a day, the zebra suffered from severe abdominal pain and subsequently died. Prior to admission, the zebra had received prophylactic anthelmintic treatment with ivermectin 3 times at 3-month intervals and was dewormed with ivermectin 30 days prior to the onset of depression. At necropsy, there were masses of ascarids in the stomach and small intestine, and intestinal perforation. There are many reports of ivermectin-resistant P. equorum in horses. However, anthelmintic resistance has not been formally demonstrated in zebras. This report describes diagnosed case of gastrointestinal impaction and intestinal perforation by P. equorum in an adult zebra. We suspect that ivermectin-resistant P. equorum larvae were the cause.

Detection of Zebra-crossing Areas Based on Deep Learning with Combination of SegNet and ResNet (SegNet과 ResNet을 조합한 딥러닝에 기반한 횡단보도 영역 검출)

  • Liang, Han;Seo, Suyoung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.39 no.3
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    • pp.141-148
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    • 2021
  • This paper presents a method to detect zebra-crossing using deep learning which combines SegNet and ResNet. For the blind, a safe crossing system is important to know exactly where the zebra-crossings are. Zebra-crossing detection by deep learning can be a good solution to this problem and robotic vision-based assistive technologies sprung up over the past few years, which focused on specific scene objects using monocular detectors. These traditional methods have achieved significant results with relatively long processing times, and enhanced the zebra-crossing perception to a large extent. However, running all detectors jointly incurs a long latency and becomes computationally prohibitive on wearable embedded systems. In this paper, we propose a model for fast and stable segmentation of zebra-crossing from captured images. The model is improved based on a combination of SegNet and ResNet and consists of three steps. First, the input image is subsampled to extract image features and the convolutional neural network of ResNet is modified to make it the new encoder. Second, through the SegNet original up-sampling network, the abstract features are restored to the original image size. Finally, the method classifies all pixels and calculates the accuracy of each pixel. The experimental results prove the efficiency of the modified semantic segmentation algorithm with a relatively high computing speed.

Pedestrian Crosswalk Design based on the Assessment of Driver Recognition (운전자 인지특성 분석을 통한 횡단보도 디자인 연구)

  • Lee, Juyoung
    • Journal of Environmental Science International
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    • v.29 no.4
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    • pp.361-369
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    • 2020
  • With the increasing role of environmental design in promoting urban safety, new design attempts have been made to improve pedestrian safety in crosswalks. This study proposes an evidence-based design solution for improving crosswalk function by conducting simulations and field experiments. Drivers with more than one-year driving experience participated in this study. Four different crosswalk design patterns were prepared: (1) a zebra pattern, (2) zebra pattern with colored triangles, (3) 3D pattern, and (4) art pattern with unique colors and design. The results supported that the zebra pattern with colored triangles could be the most effective solution for crosswalk design by increasing visibility, attention, deceleration, and landscape aesthetics. This study provided objective data to support the performance of various crosswalk patterns and suggested the need to reevaluate the present crosswalk design guidelines.

A Case Report on Hepatic Abscess in a Grant′s Zebra (얼룩말에 있어서 Streptococcus equi에 의한 간농양 발생 1례)

  • Shin Nam-Sik;Kwon Soo-Wahn;Han Duk-Hwan
    • Journal of Veterinary Clinics
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    • v.10 no.1
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    • pp.131-135
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    • 1993
  • In this case, Grant's Zebra which had been bred and exhibited in Farmland Zoological Garden for 4 years, died after treated dystocia. Result in autopsy, she had large hepatic abscess, and blood chemistry were increased G07, GPT and total billirubin. The microbiological culture with the hepatic abscess idetified the Streptococcus equi. It is diagnosed of hepatic abscess which was caused by Streptococcus equi infection.

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Application of Three-Dimensional Light Microscopy for Thick Specimen Studies

  • Rhyu, Yeon Seung;Lee, Se Jeong;Kim, Dong Heui;Uhm, Chang-Sub
    • Applied Microscopy
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    • v.46 no.2
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    • pp.93-99
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    • 2016
  • The thickness of specimen is an important factor in microscopic researches. Thicker specimen contains more information, but it is difficult to obtain well focused image with precise details due to optical limit of conventional microscope. Recently, a microscope unit that combines improved illumination system, which allows real time three-dimensional (3D) image and automatic z-stack merging software. In this research, we evaluated the usefulness of this unit in observing thick samples; Golgi stained nervous tissue and ground prepared bone, tooth, and non-transparent small sample; zebra fish teeth. Well focused image in thick samples was obtained by processing z-stack images with Panfocal software. A clear feature of neuronal dendrite branching pattern could be taken. 3D features were clearly observed by oblique illumination. Furthermore, 3D array and shape of zebra fish teeth was clearly distinguished. A novel combination of two channel oblique illumination and z-stack imaging process increased depth of field and optimized contrast, which has a potential to be further applied in the field of neuroscience, hard tissue biology, and analysis of small organic structures such as ear ossicles and zebra fish teeth.

Forgetting Stories from the Islands, Jeju and Calauit

  • Raymon D. Ritumban
    • SUVANNABHUMI
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    • v.16 no.1
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    • pp.103-123
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    • 2024
  • The traumatic experiences of people from peripheral islands are susceptible to mnemocide. Such erasure of memory is facilitated by "defensive and complicit forgetting," which, according to Aleida Assmann, leads to "protection of perpetrators." My paper reflects on the vulnerability of traumas from the islands to mnemocide by looking into [1] the massacre of communists and civilians on Jeju Island, South Korea in 1948 as described in Hyun-Kil Un's short story "Dead Silence" (2017; English trans.) and [2] the eviction of residents and indigenous people from Calauit Island, Philippines for the creation of a safari in 1976 as imagined in Annette A. Ferrer's "Pablo and the Zebra" (2017). In "Dead Silence," I direct the attention to how to the execution of the villagers-witnesses to the death of the communist guerillas-is a three-pronged violence: it is a transgression committed against the innocent civilians; an act of "erasing traces to cover up" the military crackdown on the island; and, by leaving the corpses out in the open, a display of impunity. In "Pablo and the Zebra," I second that both residents (i.e., humans and animals) experience post-traumatic stress because of their respective displacements; thus, the tension between them has got to stop. Curiously, while it concludes with a reconciliatory gesture between an elder and a zebra, no character demanded a reparation for their traumatic past per se. Could the latter be symptomatic of a silence that lets such violence "remain concealed for a long time"?