scholarly journals Intraspecific antagonism through viral toxin encoded by chronic Sulfolobus spindle-shaped virus

2021 ◽  
Vol 377 (1842) ◽  
Author(s):  
Samantha J. DeWerff ◽  
Changyi Zhang ◽  
John Schneider ◽  
Rachel J. Whitaker
Keyword(s):  
Competitive Advantage ◽  
Chronic Infection ◽  
Genetic Basis ◽  
Competitive Interactions ◽  
Theme Issue ◽  
Expression Plasmid ◽  
Host Interactions ◽  
Sulfolobus Islandicus ◽  
Nested Network

Virus–host interactions evolve along a symbiosis continuum from antagonism to mutualism. Long-term associations between virus and host, such as those in chronic infection, will select for traits that drive the interaction towards mutualism, especially when susceptible hosts are rare in the population. Virus–host mutualism has been demonstrated in thermophilic archaeal populations where Sulfolobus spindle-shaped viruses (SSVs) provide a competitive advantage to their host Sulfolobus islandicus by producing a toxin that kills uninfected strains. Here, we determine the genetic basis of this killing phenotype by identifying highly transcribed genes in cells that are chronically infected with a diversity of SSVs. We demonstrate that these genes alone confer growth inhibition by being expressed in uninfected cells via a Sulfolobus expression plasmid. Challenge of chronically infected strains with vector-expressed toxins revealed a nested network of cross-toxicity among divergent SSVs, with both broad and specific toxin efficacies. This suggests that competition between viruses and/or their hosts could maintain toxin diversity. We propose that competitive interactions among chronic viruses to promote their host fitness form the basis of virus–host mutualism. This article is part of the theme issue ‘The secret lives of microbial mobile genetic elements’.

scholarly journals Studying the genetic basis of masting

2021 ◽  
Vol 376 (1839) ◽  
Author(s):  
Akiko Satake ◽  
Dave Kelly
Keyword(s):  
Genetic Basis ◽  
Molecular Mechanisms ◽  
Mast Seeding ◽  
Ecological Genomics ◽  
Theme Issue ◽  
Natural Conditions ◽  
Genetic Level ◽  
Seed Crops

The mechanisms underlying mast seeding have traditionally been studied by collecting long-term observational data on seed crops and correlating seedfall with environmental variables. Significant progress in ecological genomics will improve our understanding of the evolution of masting by clarifying the genetic basis of masting traits and the role of natural selection in shaping those traits. Here, we summarize three important aspects in studying the evolution of masting at the genetic level: which traits govern masting, whether those traits are genetically regulated, and which taxa show wide variation in these traits. We then introduce recent studies on the molecular mechanisms of masting. Those studies measure seasonal changes in gene expression in natural conditions to quantify how multiple environmental factors combine to regulate floral initiation, which in many masting plant species is the single largest contributor to among-year variation in seed crops. We show that Fagaceae offers exceptional opportunities for evolutionary investigations because of its diversity at both the phenotypic and genetic levels and existing documented genome sequences. This article is part of the theme issue ‘The ecology and evolution of synchronized seed production in plants’.

scholarly journals Local association of Trypanosoma cruzi chronic infection foci and enteric neuropathic lesions at the tissue micro-domain scale

2021 ◽  
Author(s):  
Archie A. Khan ◽  
Harry C. Langston ◽  
Fernanda C. Costa ◽  
Francisco Olmo ◽  
Martin C. Taylor ◽  
...  
Keyword(s):  
Chronic Infection ◽  
Digestive Disease ◽  
Clinical Manifestations ◽  
Imaging Systems ◽  
Immunofluorescence Analysis ◽  
Cell Level ◽  
Host Interactions ◽  
Chronic Chagas Disease

AbstractGastrointestinal (GI) disease affects a substantial subset of chronic Chagas disease (CD) patients, but the mechanism of pathogenesis is poorly understood. The lack of a robust, predictive animal model of chronic T. cruzi infection that exhibits functional digestive disease has held back research. To address this, we combined GI tracer assays and bioluminescence in vivo infection imaging systems for diverse parasite strains to discover models exhibiting chronic digestive transit dysfunction. We identified the colon as a specific site of both tissue parasite persistence and delayed transit. Digestive CD mice exhibited significant retention of faeces in both sated and fasted conditions. Histological and immunofluorescence analysis of the enteric nervous system (ENS) revealed a dramatic reduction in the number of neurons and a loss of immunoreactivity of the enteric neural network in the colon. This model therefore recapitulates key clinical manifestations of human digestive CD. We also exploited dual bioluminescent-fluorescent parasites to analyse rare chronic infection foci in the colon at the single cell level, revealing co-localisation with ENS lesions. This indicates that long-term T. cruzi-host interactions in the colon drive pathogenesis and thus chronic disease may be preventable using anti-parasitic chemotherapy.

NEW VARIETIES OF CURRANTS AND GOOSEBERRY BREEDING PLANTS

1970 ◽  
pp. 41-46
Author(s):  
O. D. Golyaeva ◽  
O. V. Kurashev ◽  
S. D. Knyazev ◽  
А. Yu. Bakhotskaya
Keyword(s):  
Powdery Mildew ◽  
Genetic Basis ◽  
Black Currant ◽  
Leaf Spots ◽  
Agricultural Sciences ◽  
Berry Crops ◽  
New Varieties ◽  
First Time ◽  
Red Currant

The main goal of the scientific institution was and remains to improve the assortment of fruit and berry crops for the development of domestic horticulture. Black currant breeding at VNIISPK was started by A.F Tamarova and continued by the doctor of agricultural Sciences T.P.Ogoltsova and doctor of agricultural Sciences S.D. Knyazev. A long-term breeding program has been developed. The main goals of the program are to create black currant cultivars with continuous resistance to diseases, first of all powdery mildew, as wells resistance to pests, i.e. bud mite. As a result of the long-term work, over 40 black currant cultivars have been developed, 14 of them are zoned. Red currant breeding was led by the candidate of agricultural Sciences L.V. Bayanova; since 2001 the work has been continued by the candidate of agricultural Sciences O.D. Golyaeva. ‘Heinemanns Rote Spӓtlese’, the descendant of R. multiflorum Kit., was involved in the red currant breeding for the first time in Russia. On its genetic basis, a series of late maturing cultivars with long and dense racemes was created. At the Institute, in total 21cultivars of red currants have been developed, 13 of them are zoned. At present, red currant cultivars make up 25.5% of the zoned assortment in Russia. The first research on gooseberries was stated by V.P. Semakin and A.F Tamarova; since 1992 the systematic gooseberry breeding has been carried out by the candidate of agricultural Sciences O.V. Kurashev. On the basis of Grossularia robusta, we have created gooseberry forms that are resistant to powdery mildew and leaf spots. These forms are highly productive, weakly thorned, having bush habit suitable for mechanized harvest. The result of breeding activities was the transfer of 6 gooseberry cultivars to State agricultural testing: ‘Solnechny Zaychik’, ‘Nekrasovsky’, ‘Yupiter’, ‘Zemlianichny’, ‘Moryachok’ and ‘Discovery’.

Plasmodium knowlesi: a relevant, versatile experimental malaria model

Parasitology ◽  
2016 ◽  
Vol 145 (1) ◽  
pp. 56-70 ◽  
Author(s):  
ERICA M. PASINI ◽  
ANNE-MARIE ZEEMAN ◽  
ANNEMARIE VOORBERG-VAN DER WEL ◽  
CLEMENS H. M. KOCKEN
Keyword(s):  
Parasite Species ◽  
Vaccine Development ◽  
Plasmodium Knowlesi ◽  
Host Interactions ◽  
Model Studies ◽  
Human Red Blood Cells ◽  
Malaria Model ◽  
Human Primate

SUMMARYThe primate malariaPlasmodium knowlesihas a long-standing history as an experimental malaria model. Studies using this model parasite in combination with its various natural and experimental non-human primate hosts have led to important advances in vaccine development and in our understanding of malaria invasion, immunology and parasite–host interactions. The adaptation to long-termin vitrocontinuous blood stage culture in rhesus monkey,Macaca fascicularisand human red blood cells, as well as the development of various transfection methodologies has resulted in a highly versatile experimental malaria model, further increasing the potential of what was already a very powerful model. The growing evidence thatP. knowlesiis an important human zoonosis in South-East Asia has added relevance to former and future studies of this parasite species.

Bistability of somatic pattern memories: stochastic outcomes in bioelectric circuits underlying regeneration

2021 ◽  
Vol 376 (1821) ◽  
pp. 20190765 ◽  
Author(s):  
Giovanni Pezzulo ◽  
Joshua LaPalme ◽  
Fallon Durant ◽  
Michael Levin
Keyword(s):  
Large Scale ◽  
Computational Models ◽  
State Of The Art ◽  
Memory Representation ◽  
Theme Issue ◽  
Evolutionary Innovation ◽  
New Interpretation ◽  
The Brain

Nervous systems’ computational abilities are an evolutionary innovation, specializing and speed-optimizing ancient biophysical dynamics. Bioelectric signalling originated in cells' communication with the outside world and with each other, enabling cooperation towards adaptive construction and repair of multicellular bodies. Here, we review the emerging field of developmental bioelectricity, which links the field of basal cognition to state-of-the-art questions in regenerative medicine, synthetic bioengineering and even artificial intelligence. One of the predictions of this view is that regeneration and regulative development can restore correct large-scale anatomies from diverse starting states because, like the brain, they exploit bioelectric encoding of distributed goal states—in this case, pattern memories. We propose a new interpretation of recent stochastic regenerative phenotypes in planaria, by appealing to computational models of memory representation and processing in the brain. Moreover, we discuss novel findings showing that bioelectric changes induced in planaria can be stored in tissue for over a week, thus revealing that somatic bioelectric circuits in vivo can implement a long-term, re-writable memory medium. A consideration of the mechanisms, evolution and functionality of basal cognition makes novel predictions and provides an integrative perspective on the evolution, physiology and biomedicine of information processing in vivo . This article is part of the theme issue ‘Basal cognition: multicellularity, neurons and the cognitive lens’.

RETAILER’S SLOGAN IN THE FUNCTION OF PRICE IMAGE

2021 ◽  
Author(s):  
Jelena Franjković ◽  
Keyword(s):  
Competitive Advantage ◽  
Significant Role ◽  
Price Level ◽  
Marketing Mix ◽  
Consumer Perception ◽  
Successful Management ◽  
High Turnover ◽  
And Control ◽  
Price Image

The image of the retail brand and the price image of the retailer are of significant importance for achieving a competitive advantage and long-term strengthening of the overall image. Retailers’ slogans should reflect their overall strategy and facilitate and consolidate the desired positioning in the minds of customers, ie consumers. The paper studies retailers with predominantly food products, i.e., high-turnover products. Retailers who sell products of different brands find it more difficult to manage and control the positioning of their brand, and the price image also plays a significant role in this. This paper aims to investigate and compare consumer perception of retailers’ slogans and their price image. A primary survey was conducted with persons participating in the purchase of groceries for their household and included the top five retailers in the Croatian market. The results showed that the slogan of retailers can play an important role in the successful management of the price image. The compliance of the perception of the price image of retailers by the respondents with the associations of their slogans to the price level was noted. Finally, it is concluded that the harmonization of all elements of the retail marketing mix facilitates and strengthens the desired positioning in the minds of consumers, and thus the price image.

Urticaria and chronic infection foci

1995 ◽  
Vol 76 (1) ◽  
pp. 50-52
Author(s):  
R. H. Burnasheva ◽  
N. M. Rakhmatullina ◽  
A. M. Gumerova
Keyword(s):  
Chronic Infection

The results of long-term observations of patients with various forms of urticaria are generalized. The analysis of the attendant pathology considered as chronic infection foci is given. The description of various forms of the treatment of urticaria is of interest to physicions.

scholarly journals Financial Analysis of a Selected Company

2016 ◽  
Vol 24 (37) ◽  
pp. 73-92 ◽  
Author(s):  
Dušan Baran ◽  
Andrej Pastýr ◽  
Daniela Baranová
Keyword(s):  
Competitive Advantage ◽  
Financial Analysis ◽  
Business Management ◽  
Management Approach ◽  
Business Enterprise ◽  
Business Enterprises

Abstract The success of every business enterprise is directly related to the competencies of business management. The business enterprise can, as a result, create variations of how to approach the new complex and changing situations of success in the market. Therefore managers are trying during negative times to change their management approach, to ensure long-term and stable running of the business enterprise. They are forced to continuously maintain and obtain customers and suppliers. By implementing these measures they have the opportunity to achieve a competitive advantage over other business enterprises.

scholarly journals Organizational Business Interest as Organizational Request

2012 ◽  
Vol 1 (3) ◽  
pp. 509
Author(s):  
Nasser Fegh-hi Farahmand
Keyword(s):  
Competitive Advantage ◽  
Organizational Performance ◽  
Organizational Practices ◽  
Basic Ingredient ◽  
Start Up ◽  
Making A Difference ◽  
Business Interest ◽  
Or Organization

Making a difference in organization or creating the very best product or service on themarket or simply doing something loves to do. Furthermore, it seems that the emphasis onorganizational empowerment as structure, and systems has not yielded the desired results assome of the companies where these variables have been changed, after sometime, wentback to experiencing declining performance. It is therefore obvious that more researchneeds to be done to identify characteristics that enhance organizational performance.Implementing good environmental and organizational practices is good organizationalbusiness it can give a competitive advantage. This article attempts to explain theorganizational business interest by patterns of thinking. Organizations use organizationalresources as the basic ingredient for all that is required for their operations. They aretherefore eager to maintain and improve the quantity of expendable organizationalresources by not only resources utilization, but by also identifying, nurturing andmaintaining characteristics that promote organizational performance. The key toorganization success is having a organizational business interest in place. Whetherorganization is about to launch a start-up or organization have been in organizationalbusiness for years, organizational business' direction is guided by your organizationalbusiness interest. In spite of this general awareness, such long-term organizational business,strategic-level interest of organizational business has been lacking in most organizations.

scholarly journals Adaptation and competition in deteriorating environments

2021 ◽  
Vol 288 (1946) ◽  
pp. 20202967
Author(s):  
Romana Limberger ◽  
Gregor F. Fussmann
Keyword(s):  
Salt Stress ◽  
Experimental Evolution ◽  
Competitive Ability ◽  
High Salt ◽  
Competitive Interactions ◽  
Complex Interplay ◽  
Population Growth Rates ◽  
Changing Environments ◽  
History Of

Evolution might rescue populations from extinction in changing environments. Using experimental evolution with microalgae, we investigated if competition influences adaptation to an abiotic stressor, and vice versa, if adaptation to abiotic change influences competition. In a first set of experiments, we propagated monocultures of five species with and without increasing salt stress for approximately 180 generations. When assayed in monoculture, two of the five species showed signatures of adaptation, that is, lines with a history of salt stress had higher population growth rates at high salt than lines without prior exposure to salt. When assayed in mixtures of species, however, only one of these two species had increased population size at high salt, indicating that competition can alter how adaptation to abiotic change influences population dynamics. In a second experiment, we cultivated two species in monocultures and in pairs, with and without increasing salt. While we found no effect of competition on adaptation to salt, our experiment revealed that evolutionary responses to salt can influence competition. Specifically, one of the two species had reduced competitive ability in the no-salt environment after long-term exposure to salt stress. Collectively, our results highlight the complex interplay of adaptation to abiotic change and competitive interactions.

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