Mapping the main harmful algal species in the East China Sea (Yangtze River estuary) and their possible response to the main ecological status and global climate change via a global vision.

The Yangtze River Estuary (YRE) is one of the areas in China most severely affected by harmful algal blooms (HABs). This study explored the distributive patterns of HABs in the YRE and how they are influenced by the El Niño-Southern Oscillation (ENSO) and other environmental factors. Quantitative real-time PCR (qPCR) was employed to detect and quantify the four predominant HAB species in the YRE, Karenia mikimotoi, Margalefidinium polykrikoides, Prorocentrum donghaiense, and Heterosigma akashiwo.

The impact of sexual reproduction-induced vertical migration on the complexity of harmful algal blooms in Heterosigma akashiwo.

Vertical migration behaviour, which is integral to marine energy circulation, is a prevalent trait among marine organisms. However, the behaviour of phytoplankton, particularly beyond diel vertical migration (DVM), remain underexplored compared to groups like zooplankton. Through the lens of the harmful alga Heterosigma akashiwo, which exhibits active vertical migrations and unique fluctuating bloom dynamics, this study aimed to explore the ecological intricacies and diverse benefits of phytoplankton vertical migration behaviours.

Comprehensive understanding of the life history of harmful raphidophyte Heterosigma akashiwo: Integrating in situ and in vitro observations.

Heterosigma akashiwo (Raphidophyceae) is widely recognized as a species responsible for harmful algal blooms worldwide. The species has long been speculated to possess a more complex life history, attributed to the diverse morphological variations observed during cell cultivation. However, the understanding of its life history has remained insufficient due to limitations in observing transitions between life cycle stages in vitro and challenges associated with in situ investigations.

Application of a Quantitative PCR to Investigate the Distribution and Dynamics of Two Morphologically Similar Species, and (Dinophyceae) in Korean Coastal Waters.

Species of the marine dinoflagellate genus are known to produce various potent biotoxins and can form noxious blooms that cause mass mortalities of fish and shellfish. To date, harmful blooms of the species have been reported in Korea, but was recently recorded off the southern coast of Korea. Here, we developed a quantitative real-time PCR (qRT-PCR) assay with specific primer pairs for the accurate detection and quantification of these two similar-looking unarmored species, and and investigated their distribution and dynamics in Korean coastal waters.

Bloom development of toxic dinoflagellate Alexandrium catenella (Group I) in Jinhae-Masan Bay, Korea: Germination strategy of resting cysts in relation to temperature and salinity.

To better understand the role of resting cysts in the outbreak of paralytic shellfish poisoning and bloom dynamics in Jinhae-Masan Bay, Korea, this study investigated the germination features of ellipsoidal Alexandrium cysts isolated from sediments collected in winter and summer under different combinations of temperature and salinity. Morphology and phylogeny of germling cells revealed that the ellipsoidal Alexandrium cysts belong to Alexandrium catenella (Group I). The cysts could germinate across a wide range of temperature (5-25 °C) with germination success within 5 days, indicating that continuous seeding for the maintenance of vegetative cells in the water column may occur through the year without an endogenous clock to regulate germination timing.

Abiotic and biotic factors controlling sexual reproduction in populations of Pseudo-nitzschia pungens (Bacillariophyceae).

Pseudo-nitzschia pungens is a widely distributed marine pennate diatom. Hybrid zones, regions in which two different genotypes may interbreed, are important areas for speciation and ecology, and have been reported across the globe for this species. However, sexual reproduction between differing clades in the natural environment is yet to be observed and is difficult to predict.

Different Algicidal Modes of the Two Bacteria HYD0802-MK36 and KACC10292 against Harmful Cyanobacteria .

Blooms of harmful cyanobacteria lead to an adverse effect on freshwater ecosystems, and thus extensive studies on the control of this cyanobacteria's blooms have been conducted. Throughout this study, we have found that the two bacteria HYD0802-MK36 and KACC10292 are capable of killing . Interestingly, these two bacteria showed different algicidal modes.

Alexandrium catenella (Group I) and A. pacificum (Group IV) cyst germination, distribution, and toxicity in Jinhae-Masan Bay, Korea.

To better understand the outbreaks of paralytic shellfish poisoning and bloom dynamics caused by Alexandrium species in Jinhae-Masan Bay, Korea, the germination and distributions of ellipsoidal Alexandrium cysts were investigated, and paralytic shellfish toxins (PSTs) profiles and contents were determined using strains established from germling cells. The phylogeny and morphological observations revealed that the germinated vegetative cells from ellipsoidal cysts collected from the surface sediments in Jinhae-Masan Bay belong to Alexandrium catenella (Group I) and A. pacificum (Group IV) nested within A.

Effect of marine heatwaves on bloom formation of the harmful dinoflagellate Cochlodinium polykrikoides: Two sides of the same coin?

In 2018, the bloom of harmful dinoflagellate Cochlodinium polykrikoides occurred under abnormally high water temperature (WT) conditions caused by heatwaves in Korean coastal water (KCW). To better understand C. polykrikoides bloom at high WTs in 2018, we conducted field survey and laboratory experiments (the physiological and genetic differences between the two strains, CP2013 and CP2018).

Centrodinium punctatum (Dinophyceae) produces significant levels of saxitoxin and related analogs.

Centrodinium punctatum is a fusiform dinoflagellate with a global marine distribution. Due to a close phylogenetic relationship of one C. punctatum strain to Alexandrium species, toxin production of this C.

Change in Paralytic Shellfish Toxins in the Mussel Depending on Dynamics of Harmful (Group I) in the Geoje Coast (South Korea) during Bloom Season.

Paralytic shellfish toxins (PSTs) produced by (formerly ) in Korean coastal waters caused the deaths of four people (in 1986 and 1996) who consumed contaminated mussels (). This led to more detailed consideration of the risks of PST outbreaks and incidents in Korea, including the introduction of shellfish collection bans. In this study, we investigated the relationships between population dynamics and PST accumulation in the mussel Discharges from the Nakdong River affect the environmental conditions along the Geoje coast, resulting in low salinity and high nutrient levels that trigger blooms of .

Sexual reproduction and genetic polymorphism within the cosmopolitan marine diatom Pseudo-nitzschia pungens.

Different clades belonging to the cosmopolitan marine diatom Pseudo-nitzschia pungens appear to be present in different oceanic environments, however, a 'hybrid zone', where populations of different clades interbreed, has also been reported. Many studies have investigated the sexual reproduction of P. pungens, focused on morphology and life cycle, rather than the role of sexual reproduction in mixing the genomes of their parents.

Potential Cause of Decrease in Bloom Events of the Harmful Dinoflagellate in Southern Korean Coastal Waters in 2016.

Blooms of the ichthyotoxic dinoflagellate are responsible for massive fish mortality events in Korean coastal waters (KCW). They have been consistently present in southern KCW over the last two decades, but they were not observed in 2016, unlike in the previous years. Despite extensive studies, the cause of this absence of this dinoflagellate bloom remains largely unknown.

Potential effects of bacterial communities on the formation of blooms of the harmful dinoflagellate Prorocentrum after the 2014 Texas City "Y" oil spill (USA).

The association between phytoplankton blooms and oil spills is still controversial despite numerous studies. Surprisingly, to date, there have been no studies on the effect of bacterial communities (BCs) exposed to crude oil on phytoplankton growth, even though crude oil changes BCs, which can then affect phytoplankton growth and species composition. Co-culture with crude oil-exposed BCs significantly stimulated the growth of Prorocentrum texanum in the laboratory.

Cervical Cerebrospinal Fluid Leakage Concomitant with a Thoracic Spinal Intradural Arachnoid Cyst.

We encountered a very rare case of spontaneous spinal cerebrospinal fluid (CSF) leakage and a spinal intradural arachnoid cyst (AC) that were diagnosed at different sites in the same patient. These two lesions were thought to have interfered with the disease onset and deterioration. A 30-year-old man presented with sudden neck pain and orthostatic headache.

Dynamics of Amoebophrya parasites during recurrent blooms of the ichthyotoxic dinoflagellate Cochlodinium polykrikoides in Korean coastal waters.

During the bloom events of the harmful dinoflagellate Cochlodinium polykrikoides in August and October, 2012, infections by two different Amoebophrya species were observed in Korean coastal waters. To investigate the dynamics of the two parasites and their relative impact on the host populations, a quantitative real-time PCR (qPCR) method was applied to detect and quantify the parasites in the free-living and parasitic stages. Each specific primer set of the target species, Amoebophrya sp.

Can algicide (the thiazolidinedione derivative TD49) truly contribute to the restoration of microbial communities?

Harmful algal blooms (HABs) are becoming a more serious ecological threat to marine environments; they not only produce toxins, resulting in the death of marine organisms, but they also adversely affect biodiversity, which is an indicator of the health of an ecosystem. Thus, to mitigate HABs, numerous studies have been conducted to develop an effective algicide, but few studies have elucidated the effect of algicides on marine environmental health. In this study, thiazolidinedione derivative 49 (TD49), which has been developed as an algicide for the dinoflagellate Heterocapsa circularisquama, was used, and we investigated changes in phytoplankton biomass (abundance, chlorophyll a, and carbon biomass) and biodiversity (diversity, evenness, and richness) following the application of TD49.

Use of microcatheters for suction thrombectomy of acute distal occlusions.

We report our initial experience of using a microcatheter for contact aspiration of acute distal occlusions for recanalization. Endovascular technique and a case using Excelsior XT-27 microcatheter are presented. After manual suction within distal middle cerebral artery segments using a 50-ml syringe, instant and complete recanalization was obtained.

Stent-Retriever Angioplasty for Recurrent Post-Subarachnoid Hemorrhagic Vasospasm - A Single Center Experience with Long-Term Follow-Up.

Purpose: We report our experience of using stent-retrievers for recurrent cerebral vasospasm (CVS) secondary to aneurysmal subarachnoid hemorrhage (aSAH).

Methods: We performed a retrospective review of our prospectively maintained institutional database to identify all patients with recurrent CVS and treated with stent-retrievers between April 2011 and May 2017. All patients were initially treated with intra-arterial (IA) vasodilators and were subsequently re-treated with stent-retrievers if they developed recurrent vasospasm.

Cyanobacteria-specific algicidal mechanism of bioinspired naphthoquinone derivative, NQ 2-0.

To mitigate cyanobacterial blooms, the naphthoquinone derivative, NQ 2-0, which has selective algicidal activity against cyanobacteria, has been developed. However, due to a lack of information on its algicidal mechanisms, there are significant gaps in our understanding of how this substance is capable of selectively killing cyanobacteria. Here, we investigated the selective algicidal mechanisms of NQ 2-0 using target (Microcystis aeruginosa) and non-target (Cyclotella sp.

Correction to: promotes biofuel competence of in a broad range of abiotic stressors: dynamics of quorum-sensing precursors and strategic improvement in lipid productivity.

[This corrects the article DOI: 10.1186/s13068-018-1097-9.].

promotes biofuel competence of in a broad range of abiotic stressors: dynamics of quorum-sensing precursors and strategic improvement in lipid productivity.

Background: Amelioration of biofuel feedstock of microalgae using sustainable means through synthetic ecology is a promising strategy. The co-cultivation model ( and ) was evaluated for the robust biofuel production under varying stressors as well as with the selected two-stage cultivation modes. In addition, the role of metabolic exudates including the quorum-sensing precursors was assessed.