scholarly journals Conserved and species-specific oxylipin pathways in the wound-activated chemical defense of the noninvasive red alga Gracilaria chilensis and the invasive Gracilaria vermiculophylla

2012 ◽  
Vol 8 ◽  
pp. 283-289 ◽  
Author(s):  
Martin Rempt ◽  
Florian Weinberger ◽  
Katharina Grosser ◽  
Georg Pohnert
Keyword(s):  
Chemical Defense ◽  
Metabolic Profiling ◽  
Red Alga ◽  
The Novel ◽  
Gracilaria Vermiculophylla ◽  
Invasive Potential ◽  
Gracilaria Chilensis ◽  
Naturally Occurring ◽  
Species Specific

Chemical defense of the invasive red alga Gracilaria vermiculophylla has been studied and compared to that of the noninvasive but related Gracilaria chilensis. Both species rely on a wound-activated chemical defense that makes them less attractive to the herbivorous sea snail Echinolittorina peruviana. The chemical stress response of both species was monitored by LC–ESIMS-based metabolic profiling and revealed commonalities and differences. Both algae rely on a rapid lipoxygenase mediated transformation of arachidonic acid to known and novel oxylipins. Common products are 7,8-dihydroxyeicosatetraenoic acid and a novel eicosanoid with an unusual γ-lactone moiety. Several prostaglandins were predominantly formed by the invasive species. The role of some of these metabolites was investigated by surveying the attachment of E. peruviana on artificial food containing the respective oxylipins. Both algae species are defended against this general herbivore by 7,8-dihydroxyeicosatetraenoic acid, whereas the prostaglandins and the novel oxylipins were inactive at naturally occurring concentrations. The role of different oxylipins in the invasive potential of Gracilaria spp. is discussed.

Up-Regulation of Lipoxygenase, Phospholipase, and Oxylipin-Production in the Induced Chemical Defense of the Red Alga Gracilaria chilensis against Epiphytes

2011 ◽  
Vol 37 (7) ◽  
pp. 677-686 ◽  
Author(s):  
Florian Weinberger ◽  
Ulrich Lion ◽  
Ludovic Delage ◽  
Bernard Kloareg ◽  
Philippe Potin ◽  
...  
Keyword(s):  
Chemical Defense ◽  
Red Alga ◽  
Gracilaria Chilensis

scholarly journals Dimethyl sulfide acts as eat-me signal during microbial predator-prey interactions in the ocean

2021 ◽  
Author(s):  
Adva Shemi ◽  
Uria Alcolombri ◽  
Daniella Schatz ◽  
Viviana Farstey ◽  
Ron Rotkopf ◽  
...  
Keyword(s):  
Chemical Defense ◽  
Dimethyl Sulfide ◽  
Thalassiosira Pseudonana ◽  
The Novel ◽  
Aerosol Formation ◽  
Predator Prey ◽  
Oxyrrhis Marina ◽  
Algal Prey ◽  
Oceanic Carbon

Abstract Phytoplankton are key components of the oceanic carbon and sulfur cycles 1. During bloom events, some species can emit massive amounts of the organosulfur volatile dimethyl sulfide (DMS) to the atmosphere, where it can modulate aerosol formation and affect climate. In aquatic environments, DMS plays an important role as a chemical signal mediating diverse trophic-level interactions. Yet its role in microbial predator-prey interactions remains elusive with contradicting evidence for its role in algal chemical defense and in grazer’s chemoattraction to prey cells. Here, we investigated the signaling role of DMS during zooplankton-algae interactions by genetic and biochemical manipulation of the algal DMS-generating enzyme (Dimethylsulfoniopropionate lyase, DL) from the bloom-forming alga Emiliania huxleyi. We inhibited DL activity in live E. huxleyi cells by the novel DL-inhibitor 2-bromo-3-(dimethylsulfonio)-propionate (Br-DMSP) , and overexpressed DL in the model diatom Thalassiosira pseudonana. We showed that algal DL activity did not serve as anti-grazing chemical defense, and paradoxically enhanced grazing by the model microzooplankton Oxyrrhis marina and other micro- and mesozooplankton, including ciliates and copepods. Consumption of algal prey with induced DL activity also promoted O. marina’s growth. Overall, our results demonstrate that DMS-mediated herbivory may be ecologically important and prevalent during prey-predator dynamics in oceanic ecosystems. The role of DMS as an appetizing signal to grazers revealed here raises fundamental questions regarding the retention of its biosynthetic enzyme through the evolution of dominant bloom-forming phytoplankton in the ocean.

Fine structure and properties of defects in naturally occurring silicates and oxides

1990 ◽  
Vol 48 (4) ◽  
pp. 460-461
Author(s):  
David R. Veblen
Keyword(s):  
Chemical Reactions ◽  
High Resolution Electron Microscopy ◽  
Extended Defects ◽  
Single Chain ◽  
Naturally Occurring ◽  
Resolution Electron ◽  
Fine Structures ◽  
Image Simulations ◽  
Similar Crystal Structure

Extended defects and interfaces control many processes in rock-forming minerals, from chemical reactions to rock deformation. In many cases, it is not the average structure of a defect or interface that is most important, but rather the structure of defect terminations or offsets in an interface. One of the major thrusts of high-resolution electron microscopy in the earth sciences has been to identify the role of defect fine structures in reactions and to determine the structures of such features. This paper will review studies using HREM and image simulations to determine the structures of defects in silicate and oxide minerals and present several examples of the role of defects in mineral chemical reactions. In some cases, the geological occurrence can be used to constrain the diffusional properties of defects.The simplest reactions in minerals involve exsolution (precipitation) of one mineral from another with a similar crystal structure, and pyroxenes (single-chain silicates) provide a good example. Although conventional TEM studies have led to a basic understanding of this sort of phase separation in pyroxenes via spinodal decomposition or nucleation and growth, HREM has provided a much more detailed appreciation of the processes involved.

ROLE OF THE NOVEL INTRODUCED PAN-INTESTINAL CAPSULE ENDOSCOPY SYSTEM IN CELIAC DISEASE

2019 ◽  
Author(s):  
F Foerster ◽  
K Mönkemüller ◽  
PR Galle ◽  
H Neumann
Keyword(s):  
Celiac Disease ◽  
Capsule Endoscopy ◽  
The Novel

Patterns: Rosamond Lehmann

2018 ◽  
Author(s):  
Vike Martina Plock
Keyword(s):  
Coming Of Age ◽  
Public Image ◽  
Market Forces ◽  
The Novel ◽  
Fashion Industry ◽  
To The Lighthouse ◽  
Fashion Magazines ◽  
Female Authorship ◽  
Rosamond Lehmann

This chapter analyzes the role of fashion as a discursive force in Rosamond Lehmann’s 1932 coming-of-age novel Invitation to the Waltz. Reading the novel alongside such fashion magazines as Vogue, it demonstrates Lehmann’s awareness that 1920s fashion, in spite of its carefully stylized public image as harbinger of originality, emphasized the importance of following preconceived (dress) patterns in the successful construction of modern feminine types. Invitation to the Waltz, it argues, opposes the production of patterned types and celebrates difference and disobedience in its stead. At the same time, the novel’s formal appearance is nonetheless dependent on the very same tenets it criticizes. On closer scrutiny, it is seen to reveal its resemblance to Virginia Woolf’s To the Lighthouse (1927). A tension between imitation and originality determines sartorial fashion choices. This chapter shows that female authorship in the inter-war period was subjected to the same market forces that controlled and sustained the organization of the fashion industry.

SARS-COV2 virus and Coronavirus disease (COVID-19)

2020 ◽  
Vol 11 (SPL1) ◽  
pp. 977-982
Author(s):  
Mohamed J. Saadh ◽  
Bashar Haj Rashid M ◽  
Roa’a Matar ◽  
Sajeda Riyad Aldibs ◽  
Hala Sbaih ◽  
...  
Keyword(s):  
Close Contact ◽  
Antiviral Agents ◽  
Health Concern ◽  
The Novel ◽  
Global Public Health ◽  
Fatal Disease ◽  
Mild Disease ◽  
Life Threatening ◽  
Novel Coronavirus

SARS-COV2 virus causes Coronavirus disease (COVID-19) and represents the causative agent of a potentially fatal disease that is of great global public health concern. The novel coronavirus (2019) was discovered in 2019 in Wuhan, the market of the wet animal, China with viral pneumonia cases and is life-threatening. Today, WHO announces COVID-19 outbreak as a pandemic. COVID-19 is likely to be zoonotic. It is transmitted from bats as intermediary animals to human. Also, the virus is transmitted from human to human who is in close contact with others. The computerized tomographic chest scan is usually abnormal even in those with no symptoms or mild disease. Treatment is nearly supportive; the role of antiviral agents is yet to be established. The SARS-COV2 virus spreads faster than its two ancestors, the SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV), but has lower fatality. In this article, we aimed to summarize the transmission, symptoms, pathogenesis, diagnosis, treatment, and vaccine to control the spread of this fatal disease.

THE ROLE OF ARTISTIC PSYCHOLOGY IN THE METAPHORICAL HARMONY OF MAN AND THE REALITY OF LIFE

2020 ◽  
Vol 2 (3) ◽  
pp. 19-23
Author(s):  
Shakhlo Botirova ◽  
Keyword(s):  
The Novel

In this article , in the novel “Rebellion and obedience” by Ulugbek Hamdam, the author analyzes the artistic psychological description of a person on the path of development in the center of an integral complex metaphorical system of being. The novel “Rebellion and obedience” is based onthe method of metaphorization of reality. In it, a personexperiences vertigo about who he is and what powerful being he possesses. The reason for this is a riot. After much agony, he obeys. Allegedly thus proves its existence. Finds answers to certain riddles

Le premier moment de l’art dans À la recherche du temps perdu de Marcel Proust – une « leçon d’idéalisme » ?

2020 ◽  
pp. 25-40
Author(s):  
Larisa Botnari
Keyword(s):  
Essential Role ◽  
Marcel Proust ◽  
The Self ◽  
Philosophy Of Art ◽  
The Novel ◽  
Philosophical Interpretation ◽  
German Philosopher ◽  
Lost Time ◽  
Aesthetic Thinking

Although very famous, some key moments of the novel In Search of Lost Time, such as those of the madeleine or the uneven pavement, often remain enigmatic for the reader. Our article attempts to formulate a possible philosophical interpretation of the narrator's experiences during these scenes, through a confrontation of the Proustian text with the ideas found in the System of Transcendental Idealism (1800) of the German philosopher F. W. J. Schelling. We thus try to highlight the essential role of the self in Marcel Proust's aesthetic thinking, by showing that the mysterious happiness felt by the narrator, and from which the project of creating a work of art is ultimately born, is similar to the experiences of pure self-consciousness evoked and analyzed by Schellingian philosophy of art.

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