scholarly journals Screening of Chilean fish-killing microalgae using a gill cell-based assay

2020 ◽  
Vol 48 (2) ◽  
pp. 329-335 ◽  
Author(s):  
Jorge I. Mardones
Keyword(s):  
Cell Viability ◽  
Algal Blooms ◽  
Algal Species ◽  
Economic Losses ◽  
The Novel ◽  
Significant Progress ◽  
Gill Cell ◽  
Major Threat ◽  
Highly Sensitive ◽  
Gill Cells

Fish-killing algal species are responsible for important global economic losses to the finfish industry. Chile is the world’s second-largest salmon exporter, and fish-killing algal blooms have widely impacted its production in the last decades. The lack of standardized analytical methods to quantify and characterize the so-called “ichthyotoxins” has hindered our understanding of the underlying ichthyotoxic modes of action. The novel application of a highly sensitive and reproducible fish RTgill-W1 cell line-based assay has allowed significant progress in the field. In this study, the ichthyotoxic potency of the main microalgae species, which has been reported in fish-killing events in the historical Chilean monitoring programs, was assessed. The dinoflagellate Karenia selliformis was the most ichthyotoxic species against the RTgill-W1 (cell viability down to 8%), representing the major threat for the local salmon industry. In comparison, the raphidophyte Heterosigma akashiwo and the dinoflagellate Prorocentrum micans were the least toxic (gill cell viability down to 81 and 89%, respectively). Importantly, ichthyotoxic flagellates were more toxic to fish gill cells upon rupture. These results have important implications for the mitigation and management of algal blooms by the salmon industry.

scholarly journals Sensitive Aflatoxin B1 Detection Using Nanoparticle-Based Competitive Magnetic Immunodetection

Toxins ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 337 ◽  
Author(s):  
Jan Pietschmann ◽  
Holger Spiegel ◽  
Hans-Joachim Krause ◽  
Stefan Schillberg ◽  
Florian Schröper
Keyword(s):  
Detection Limit ◽  
Aflatoxin B1 ◽  
Magnetic Particles ◽  
Reference Method ◽  
Economic Losses ◽  
The Novel ◽  
Laboratory Equipment ◽  
Detection Approach ◽  
Highly Sensitive ◽  
Highly Sensitive Detection

Food and crop contaminations with mycotoxins are a severe health risk for consumers and cause high economic losses worldwide. Currently, different chromatographic- and immuno-based methods are used to detect mycotoxins within different sample matrices. There is a need for novel, highly sensitive detection technologies that avoid time-consuming procedures and expensive laboratory equipment but still provide sufficient sensitivity to achieve the mandated detection limit for mycotoxin content. Here we describe a novel, highly sensitive, and portable aflatoxin B1 detection approach using competitive magnetic immunodetection (cMID). As a reference method, a competitive ELISA optimized by checkerboard titration was established. For the novel cMID procedure, immunofiltration columns, coated with aflatoxin B1-BSA conjugate were used for competitive enrichment of biotinylated aflatoxin B1-specific antibodies. Subsequently, magnetic particles functionalized with streptavidin can be applied to magnetically label retained antibodies. By means of frequency mixing technology, particles were detected and quantified corresponding to the aflatoxin content in the sample. After the optimization of assay conditions, we successfully demonstrated the new competitive magnetic detection approach with a comparable detection limit of 1.1 ng aflatoxin B1 per mL sample to the cELISA reference method. Our results indicate that the cMID is a promising method reducing the risks of processing contaminated commodities.

scholarly journals Sex Differences in Spatial Activity and Anxiety Levels in the COVID-19 Pandemic from Evolutionary Perspective

2021 ◽  
Vol 13 (3) ◽  
pp. 1110
Author(s):  
Olga Semenova ◽  
Julia Apalkova ◽  
Marina Butovskaya
Keyword(s):  
Environmental Risks ◽  
Economic Losses ◽  
General Level ◽  
The Novel ◽  
Health Attitudes ◽  
Spatial Activity ◽  
Sexual Specialization ◽  
The Face ◽  
Novel Virus ◽  
Virus Spreading

Despite the enforced lockdown regime in late March 2020 in Russia, the phenomenon of the continued virus spreading highlighted the importance of studies investigating the range of biosocial attributes and spectrum of individual motivations underlying the permanent presence of the substantial level of spatial activity. For this matter, we conducted a set of surveys between March and June 2020 (N = 492). We found that an individual’s health attitude is the most consistent factor explaining mobility differences. However, our data suggested that wariness largely determines adequate health attitudes; hence, a higher level of wariness indirectly reduced individual mobility. Comparative analysis revealed the critical biosocial differences between the two sexes, potentially rooted in the human evolutionary past. Females were predisposed to express more wariness in the face of new environmental risks; therefore, they minimize their mobility and outdoor contacts. In contrast to them, the general level of spatial activity reported by males was significantly higher. Wariness in the males’ sample was less associated with the novel virus threat, but to a great extent, it was predicted by the potential economic losses variable. These findings correspond to the evolutionary predictions of sexual specialization and the division of family roles.

scholarly journals A Review of Nontraditional Biomanipulation

2008 ◽  
Vol 8 ◽  
pp. 1184-1196 ◽  
Author(s):  
Xia Zhang ◽  
Ping Xie ◽  
Xiaoping Huang
Keyword(s):  
Algal Blooms ◽  
Algal Species ◽  
Planktivorous Fish ◽  
Bighead Carp ◽  
Cyanobacterial Blooms ◽  
Management Tool ◽  
Nutrient Concentrations ◽  
Effective Management ◽  
Nuisance Algae ◽  
The Impact

The aim of this review is to identify problems, find general patterns, and extract recommendations for successful management using nontraditional biomanipulation to improve water quality. There are many obstacles that prevent traditional biomanipulation from achieving expectations: expending largely to remove planktivorous fish, reduction of external and internal phosphorus, and macrophyte re-establishment. Grazing pressure from large zooplankton is decoupled in hypereutrophic waters where cyanobacterial blooms flourish. The original idea of biomanipulation (increased zooplankton grazing rate as a tool for controlling nuisance algae) is not the only means of controlling nuisance algae via biotic manipulations. Stocking phytoplanktivorous fish may be considered to be a nontraditional method; however, it can be an effective management tool to control nuisance algal blooms in tropical lakes that are highly productive and unmanageable to reduce nutrient concentrations to low levels.Although small enclosures increase spatial overlap between predators and prey, leading to overestimates of the impact of predation, microcosm and whole-lake experiments have revealed similar community responses to major factors that regulate lake communities, such as nutrients and planktivorous fish. Both enclosure experiments and large-scale observations revealed that the initial phytoplankton community composition greatly impacted the success of biomanipulation. Long-term observations in Lake Donghu and Lake Qiandaohu have documented that silver carp (Hypophthalmichthys molitrix) and bighead carp (H. nobilis) (two filter-feeding planktivorous species commonly used in management) can suppress Microcystis blooms efficiently. The introduction of silver and bighead carp could be an effective management technique in eutrophic systems that lack macrozooplankton. We confirmed that nontraditional biomanipulation is only appropriate if the primary aim is to reduce nuisance blooms of large algal species, which cannot be controlled effectively by large herbivorous zooplankton. Alternatively, this type of biomanipulation did not work efficiently in less eutrophic systems where nanophytoplankton dominated.

Impact of natural hazards on the evolving COVID-19 pandemic: cases from Greece

2021 ◽  
Author(s):  
Maria Mavrouli ◽  
Spyridon Mavroulis ◽  
Efthymios Lekkas
Keyword(s):  
Built Environment ◽  
Natural Hazards ◽  
Local Population ◽  
World Health ◽  
Economic Losses ◽  
The Novel ◽  
Hydrological Hazards ◽  
Eastern Aegean ◽  
The Impact ◽  
Post Disaster

<p>The first confirmed COVID-19 case was reported in December 2019. Over the first months of 2020, the novel SARS-CoV-2 virus was spread worldwide resulting in the declaration on March 11, 2020 of a global COVID-19 pandemic by the World Health Organization. The evolving pandemic has resulted in over 1900000 fatalities worldwide (as of January 8, 2021), while all sectors of the everyday life has been affected in numerous and varied ways. Natural hazards did not stop for the novel coronavirus. When the natural hazards cross the path of an evolving pandemic, compound emergencies emerge and are characterized by various effects and new unprecedented challenges.</p><p>Greece was no exception. Geological, hydrological and meteorological hazards took place in several parts of the country and they affected the local population, the natural and the built environment including buildings, infrastructures and lifelines. Among the most destructive effects in terms of human and economic losses was the March 21, 2020, Mw=5.7, Epirus (northwestern Greece) earthquake, the August 9, 2020, Evia (central Greece) flood, the September 17, 2020, Ianos medicane and the October 30, 2020, Mw=7.0, Samos (Eastern Aegean Sea) earthquake.</p><p>In order to identify the potential impact of the aforementioned disasters on the evolution of the COVID-19 pandemic in the disaster-affected areas, the officially reported laboratory-confirmed daily COVID-19 cases for the pre- and post- disaster periods from the disaster-affected areas were used. The impact of disasters in the evolution of the pandemic in the studied disaster-affected areas comprises increasing and decreasing trends and stability of the COVID-19 cases during the post-disaster period. More specifically, the geological and the hydrological hazards and the induced disasters negligibly affected the evolution of pandemic in the affected areas, while the hydrometeorological hazards resulted in increasing trends of the post-disaster reported COVID-19 cases in various affected areas.</p><p>The detected trends are strongly associated with the pre-existing viral load and infection rate in the disaster-affected areas, to the emergency response actions adapted to adopt provisional measures for the mitigation and elimination of COVID-19 consequences, to demographic features of the affected areas and to the intensity of the induced disasters and their effects on the local population (fatalities and injuries), the natural environment (primary and secondary environmental effects) and the built environment (structural damage to buildings, infrastructures and lifelines).</p>

scholarly journals Sesquiterpenes and Cyclodepsipeptides from Marine-Derived Fungus Trichoderma longibrachiatum and Their Antagonistic Activities against Soil-Borne Pathogens

Marine Drugs ◽  
2020 ◽  
Vol 18 (3) ◽  
pp. 165 ◽  
Author(s):  
Feng-Yu Du ◽  
Guang-Lin Ju ◽  
Lin Xiao ◽  
Yuan-Ming Zhou ◽  
Xia Wu
Keyword(s):  
Phytopathogenic Fungi ◽  
Economic Losses ◽  
The Novel ◽  
Root Knot Nematode ◽  
Trichoderma Longibrachiatum ◽  
Soil Borne Pathogens ◽  
Antifungal Potential ◽  
Antagonistic Potential ◽  
Southern Root Knot Nematode ◽  
Better Than

Soil-borne pathogens, including phytopathogenic fungi and root-knot nematodes, could synergistically invade vegetable roots and result in serious economic losses. The genus of Trichoderma has been proven to be a promising reservoir of biocontrol agents in agriculture. In this study, the search for antagonistic metabolites from a marine-derived fungus, Trichoderma longibrachiatum, obtained two structural series of sesquiterpenes 1–6 and cyclodepsipeptides 7–9. Notably, the novel 1 was a rare norsesquiterpene characterized by an unprecedented tricyclic-6/5/5-[4.3.1.01,6]-decane skeleton. Their structures were elucidated by extensive spectroscopic analyses, while the absolute configuration of novel 1 was determined by the comparison of experimental and calculated ECD spectra. The novel 1 and known 2 and 3 showed significant antifungal activities against Colletotrichum lagrnarium with MIC values of 8, 16, and 16 μg/mL respectively, even better than those of the commonly used synthetic fungicide carbendazim with 32 μg/mL. They also exhibited antifungal potential against carbendazim-resistant Botrytis cinerea. Cyclodepsipeptides 7–9 showed moderate nematicidal activities against the southern root-knot nematode (Meloidogyne incognita). This study constitutes the first report on the antagonistic effects of metabolites from T. Longibrachiatum against soil-borne pathogens, also highlighting the integrated antagonistic potential of marine-derived T. Longibrachiatum as a biocontrol agent.

scholarly journals Population Genetic Analysis of Phytophthora parasitica From Tobacco in Chongqing, Southwestern China

Plant Disease ◽  
2019 ◽  
Vol 103 (10) ◽  
pp. 2599-2605 ◽  
Author(s):  
Qiang Zhang ◽  
Ruirui Feng ◽  
Qing Zheng ◽  
Jinyang Li ◽  
Zhirou Liu ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
Mating Type ◽  
Population Genetic ◽  
Population Analysis ◽  
Genotypic Diversity ◽  
Control Measures ◽  
Economic Losses ◽  
Phytophthora Parasitica ◽  
Population Genetic Analysis ◽  
Highly Sensitive

Tobacco black shank, caused by Phytophthora parasitica, is one of the most notorious tobacco diseases and causes huge economic losses worldwide. Understanding the genetic variation of P. parasitica populations is essential to the development of disease control measures. In this research, 210 simple sequence repeat (SSR) markers for P. parasitica were identified, 10 of which were polymorphic among nine reference strains. We further performed population genetic analysis of 245 P. parasitica isolates randomly collected from tobacco fields in Chongqing for mating type, molecular variation at 14 SSR loci (four of which were identified previously), and sensitivity to the fungicide metalaxyl. The results showed that the A2 mating type was dominant and no A1 mating type isolate was discovered. SSR genotyping distinguished 245 P. parasitica isolates into 46 genotypes, four of which were dominant in the population. Low genotypic diversity and excess heterozygosity were common in nearly all of the populations from Chongqing. Population analysis showed that no differentiation existed among different populations. All isolates tested were highly sensitive to metalaxyl. Taken together, our results showed that the P. parasitica populations from tobacco fields in Chongqing belonged to a clonal lineage and were highly sensitive to metalaxyl.

scholarly journals Dual Wavelength Imaging Allows Analysis of Membrane Fusion of Influenza Virus inside Cells

2006 ◽  
Vol 80 (4) ◽  
pp. 2013-2018 ◽  
Author(s):  
Tatsuya Sakai ◽  
Masanobu Ohuchi ◽  
Masaki Imai ◽  
Takafumi Mizuno ◽  
Kazunori Kawasaki ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Membrane Fusion ◽  
Imaging Technique ◽  
Rapid Analysis ◽  
Virus Infectivity ◽  
Viral Fusion ◽  
The Novel ◽  
Influenza Virus Hemagglutinin ◽  
Highly Sensitive ◽  
Highly Sensitive Detection

ABSTRACT Influenza virus hemagglutinin (HA) is a determinant of virus infectivity. Therefore, it is important to determine whether HA of a new influenza virus, which can potentially cause pandemics, is functional against human cells. The novel imaging technique reported here allows rapid analysis of HA function by visualizing viral fusion inside cells. This imaging was designed to detect fusion changing the spectrum of the fluorescence-labeled virus. Using this imaging, we detected the fusion between a virus and a very small endosome that could not be detected previously, indicating that the imaging allows highly sensitive detection of viral fusion.

Abstract 5034: Healthy and cancerous serum RNA profiling by the novel RNA extraction reagent and highly sensitive DNA chip

2012 ◽  
Author(s):  
Satoko Takizawa ◽  
Makiko Ichikawa ◽  
Hiroko Sudo ◽  
Yoji Ueda ◽  
Hideo Akiyama
Keyword(s):  
Rna Extraction ◽  
Dna Chip ◽  
The Novel ◽  
Rna Profiling ◽  
Highly Sensitive

Nutrient-related selection mechanisms in marine phytoplankton communities and the impact of eutrophication on the planktonic food web

1995 ◽  
Vol 32 (4) ◽  
pp. 63-75 ◽  
Author(s):  
R. Riegman
Keyword(s):  
Algal Blooms ◽  
Algal Biomass ◽  
Resource Competition ◽  
Water Quality Management ◽  
Algal Species ◽  
Marine Phytoplankton ◽  
Commercial Fish ◽  
N Limitation ◽  
Phytoplankton Communities ◽  
The Impact

A general increase in nutrient discharges during the last few decades has caused various changes in the algal community structure along the European continental coast. Coincidentally and maybe consequently, the foodweb structure and functioning has altered in local areas causing various phenomena like oxygen depletion, mortality of groups of organisms, foam on beaches, and an increase in the productivity of benthic communities and some commercial fish species. The observed increases in algal biomass and shifts in species composition are discussed in relation to the involved key mechanisms: resource competition and selective grazing. Along the Dutch coastal zone of the North Sea eutrophication has caused a doubling of the yearly averaged algal biomass during the past three decades. The sudden appearance of Phaeocystis summer blooms coincided with a shift from P-limitation towards N-limitation in the Dutch coastal area due to a stronger increase in P-discharge relative to the increase in N-discharge. Competition experiments in continuous cultures showed Phaeocystis to become dominant under N-limitation. Additionally, the large Phaeocystis colonies, which can reach a diameter up to one centimetre, escape from microzooplankton grazing. A computer model is presented which demonstrates a shift from bottom-up towards top-down control if the pelagic environment becomes eutrophicated. Implementation of this concept in a size-differential phytoplankton control model generates the prediction that algal blooms are dominated by species that escape from grazing by those zooplankton species which have a high potential numerical response. In marine environments these are microzooplankton species. These organisms mainly feed on cyanobacteria, prochlorophytes and some nano-algal species. One of the consequences for foodweb structure and the carbon fluxes in marine foodwebs is that eutrophication will lead to the dominance of poorly edible algal species. Eutrophication favours the downward transport of carbon and nutrients towards the sediments not only due to higher algal biomasses but also as a consequence of a shift towards larger algal species with higher sedimentation characteristics. An example is given how these new insights can be used for water quality management purposes.

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