Publications by authors named "Eun Young Yoon"

Phytoplankton production in coastal waters influences seafood production and human health and can lead to harmful algal blooms. Water temperature and eutrophication are critical factors affecting phytoplankton production, although the combined effects of warming and nutrient changes on phytoplankton production in coastal waters are not well understood. To address this, phytoplankton production changes in natural waters were investigated using samples collected over eight months, and under 64 different initial conditions, established by combining four different water temperatures (i.

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The phototrophic euglenophyte Eutreptiella eupharyngea often causes blooms in the coastal waters of many countries, but its mode of nutrition has not been assessed. This species has previously been considered as exclusively auxotrophic. To explore whether E.

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Article Synopsis
  • Researchers isolated a compound called ostreol B from the toxic dinoflagellate Ostreopsis cf. ovata in South Korea.
  • They used NMR spectroscopy techniques to identify its chemical structure, which features a tetrahydropyran ring, two double bonds, and 21 hydroxyl groups.
  • The study also revealed that ostreol B displayed moderate cytotoxic effects on various cell lines, including HepG2, Neuro-2a, and HCT-116.
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Two new compounds-a trioxilin and a sulfoquinovosyl diacylglycerol (SQDG)-were isolated from the methanolic extract of the heterotrophic dinoflagellate cultivated by feeding on dried yeasts. The trioxilin was identified as (4,8,13,16,19) -7(),10(),11()-trihydroxydocosapentaenoic acid (), and the SQDG was identified as (2)-1--hexadecanosy-2--docosahexaenoyl-3--(6-sulfo-α-d-quinovopyranosyl)-glycerol () by a combination of nuclear magnetic resonance (NMR) spectra, mass analyses, and chemical reactions. The two compounds were associated with docosahexaenoic acid, which is a major component of .

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The dinoflagellate Alexandrium spp. have received much attention due to their harmful effects on diverse marine organisms, including commercially important species. For minimizing loss due to red tides or blooms of Alexandrium spp.

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Actions taking place in the environment are critical for our survival. We review evidence on attention to action, drawing on sets of converging evidence from neuropsychological patients through to studies of the time course and neural locus of action-based cueing of attention in normal observers. We show that the presence of action relations between stimuli helps reduce visual extinction in patients with limited attention to the contralesional side of space, while the first saccades made by normal observers and early perceptual and attentional responses measured using electroencephalography/event-related potentials are modulated by preparation of action and by seeing objects being grasped correctly or incorrectly for action.

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Ostreol A was isolated from cultures of the epiphytic dinoflagellate Ostreopsis cf. ovata from the coastal waters of Jeju Island, Korea. The compound, a non-palytoxin derivative, has a polyhydroxy chain ending with the primary amino group and contains an amide bond, along with two tetrahydropyran rings in the chain.

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Few protistan grazers feed on toxic dinoflagellates, and low grazing pressure on toxic dinoflagellates allows these dinoflagellates to form red-tide patches. We explored the feeding ecology of the newly described heterotrophic dinoflagellate Gyrodinium moestrupii when it fed on toxic strains of Alexandrium minutum, Alexandrium tamarense, and Karenia brevis and on nontoxic strains of A. tamarense, Prorocentrum minimum, and Scrippsiella trochoidea.

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There is considerable evidence that there are anatomically and functionally distinct pathways for action and object recognition. However, little is known about how information about action and objects is integrated. This study provides fMRI evidence for task-based selection of brain regions associated with action and object processing, and on how the congruency between the action and the object modulates neural response.

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The heterotrophic dinoflagellate Gyrodinium moestrupii n. sp. is described based on live cells and cells prepared for light, scanning electron, and transmission electron microscopy.

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We carried out a study examining the electrophysiological responses when participants made object decisions to objects and non-objects subject to congruent and incongruent hand-grip actions. Despite the grip responses being irrelevant to the task, event-related potentials were sensitive to the handgrip. There were effects of grip congruency on both P1 and N1 components, over both posterior and motor cortices, with the effects emerging most strongly for familiar objects.

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Coolia spp. are epiphytic and benthic dinoflagellates. Herein, we report for the first time, the occurrence of Coolia canariensis and Coolia malayensis in Korean waters.

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Woloszynskia species are dinoflagellates in the order Suessiales inhabiting marine or freshwater environments; their ecophysiology has not been well investigated, in particular, their trophic modes have yet to be elucidated. Previous studies have reported that all Woloszynskia species are photosynthetic, although their mixotrophic abilities have not been explored. We isolated a dinoflagellate from coastal waters in western Korea and established clonal cultures of this dinoflagellate.

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We demonstrate that right-handed participants make speeded classification responses to pairs of objects that appear in standard co-locations for right-handed actions relative to when they appear in reflected locations. These effects are greater when participants "weight" information for action when deciding if 2 objects are typically used together, compared with deciding if objects typically occur in a given context. The effects are enhanced, and affect both types of decision, when an agent is shown holding the objects.

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Two experiments are reported that use patients with visual extinction to examine how visual attention is influenced by action information in images. In Experiment 1 patients saw images of objects that were either correctly or incorrectly colocated for action, with the objects held by hands that were congruent or incongruent with those used premorbidly by the patients. The images were also shown from a 1st- and 3rd-person perspective.

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We discuss two commentaries that we have received on our target article (Humphreys et al., 2010). We elaborate on the evidence for action effects on extinction and discuss whether these effects occur pre or post the selection of a response.

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In this study, we assessed the interaction occurring between the rice weevil and two storage molds (Aspergillus candidus Link and Aspergillus niger Van Tiegem) that prefer different moisture regimens under rice storage conditions. Rice weevil induced rapid population growth in both of the storage molds. The colony forming units (CFUs) of A.

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We discuss evidence indicating that human visual attention is strongly modulated by the potential of objects for action. The possibility of action between multiple objects enables the objects to be attended as a single group, and the fit between individual objects in a group and the action that can be performed influences responses to group members. In addition, having a goal state to perform a particular action affects the stimuli that are selected along with the features and area of space that is attended.

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Synthesis and biological evaluation of various colchicine analogues through the mixed-lymphocyte reaction (MLR), lymphoproliferation, and inhibitory effects on the inflammatory genes are described. In addition, a new series of immunosuppressive agents developed on the structural basis of colchicine, as well as their structure-activity relationships is reported. The most potent analogue 20a exhibited an excellent immunosuppressive activity on in vivo skin-allograft model, which is comparable to that of cyclosporin A.

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Colchicine has been shown to regulate the expression of inflammatory gene, but this compound possesses much weaker anti-inflammatory activity. In this study, we synthesized a new colchicine derivative CT20126 and examined its immunomodulatory property. CT20126 was found to have immunosuppressive effects by inhibiting lymphocyte proliferation without cytotoxicity and effectively inhibit the transcriptional expression of the inflammatory genes, iNOS, TNF-alpha, and IL-1beta, in macrophages stimulated by LPS.

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This article reports evidence that two variables--object viewpoint and semantic priming--differentially affect action and semantic decisions to objects. Changing the viewing angle of an object, so that its graspable parts are oriented away from observers, disrupted action decisions but had little effect on semantic categorization. In contrast, semantic priming influenced semantic categorization and object naming, but not action decisions.

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We report three experiments in which name verification responses to either objects (Experiments 1 and 2) or hand movements (Experiment 3) were compared with action decisions, where participants verified whether an object is typically used in the way described by a verbal label. In Experiments 1 and 2, we report that action decisions show more consistent and larger effects of the congruency of either a handgrip or a type of movement than do name verification responses, although there was some effect of the congruency of the handgrip on name verification. In Experiment 3, we demonstrate that the congruency of the object being moved affects both action and name verification responses to hand movements.

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Visual search is facilitated if half the distractors are presented as a preview prior to the presentation of the target and second set of distractors--the preview benefit [Watson, D. G., & Humphreys, G.

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We contrast naming from pictures, and reading words, for objects and verbs (actions relating to the objects) in a patient with a large, posterior left-hemisphere lesion. We present evidence for spared picture naming for verbs relative to objects, whilst the opposite pattern of sparing occurred in reading. Objects were also spared relative to verbs in tasks requiring that written words be matched to either pictures or auditory words, in the presence of semantically related or unrelated distractors.

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Several novel 7-alkylamino-2-methylquinoline-5,8-diones (2) were synthesized from 2,5-dimethoxyaniline in five steps via the Skraup reaction followed by demethylations, oxidative bromination, amination, and debromination. We have achieved an unusual hydrobromic acid catalyzed debromination reactions of several 6-bromo-7-alkylamino-2-methylquinoline-5,8-diones, giving 7-alkylamino-2-methylquinoline-5,8-diones in good yields.

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