scholarly journals HAP2-Mediated Gamete Fusion: Lessons From the World of Unicellular Eukaryotes

2022 ◽  
Vol 9 ◽  
Author(s):  
Jennifer F. Pinello ◽  
Theodore G. Clark
Keyword(s):  
Tetrahymena Thermophila ◽  
Model Organism ◽  
Mating Types ◽  
Protozoan Parasites ◽  
Free Living ◽  
Gamete Fusion ◽  
Unicellular Eukaryotes ◽  
Current State ◽  
The World

Most, if not all the cellular requirements for fertilization and sexual reproduction arose early in evolution and are retained in extant lineages of single-celled organisms including a number of important model organism species. In recent years, work in two such species, the green alga, Chlamydomonas reinhardtii, and the free-living ciliate, Tetrahymena thermophila, have lent important new insights into the role of HAP2/GCS1 as a catalyst for gamete fusion in organisms ranging from protists to flowering plants and insects. Here we summarize the current state of knowledge around how mating types from these algal and ciliate systems recognize, adhere and fuse to one another, current gaps in our understanding of HAP2-mediated gamete fusion, and opportunities for applying what we know in practical terms, especially for the control of protozoan parasites.

Jerzy Topolski’s Marxist Anthropocentrism

2021 ◽  
Vol 15 (3) ◽  
pp. 361-377
Author(s):  
Ewa Domańska ◽  
Paul Vickers
Keyword(s):  
Historical Materialism ◽  
Philosophy Of History ◽  
Marxist Theory ◽  
Collective Agency ◽  
Future Developments ◽  
The Past ◽  
Current State ◽  
The World ◽  
Separate Discipline

Abstract In this article I demonstrate that the ideas outlined in Jerzy Topolski’s Methodology of History (Polish 1968, English translation 1976) could not only offer a reference point for and indeed enrich ongoing debates in the philosophy of history, but also help to set directions for future developments in the field. To support my argument, I focus on two themes addressed in Topolski’s work: 1) the understanding of the methodology of history as a separate discipline and its role both in defending the autonomy of history and in creating an integrated knowledge of the past, which I read here through the lens of the current merging of the humanities and natural sciences; and 2) the role of a Marxist anthropocentrism based on the notion of humans as the creators of history, which I consider here in the context of the ongoing critique of anthropocentrism. I point to the value of continuing to use concepts drawn from Marxist vocabulary, such as alienation, emancipation, exploitation and overdetermination, for interpreting the current state of the world and humanity. I stress that Marxist anthropocentrism, with its support for individual and collective agency, remains crucial to the creation of emancipatory theories and visions of the future, even if it has faced criticism for its Eurocentrism and might seem rather familiar and predictable when viewed in the context of the contemporary humanities. Nevertheless, new manifestations of Marxist theory, in the form of posthumanist Marxism and an interspecies historical materialism that transcends anthropocentrism, might play an important role in redefining the humanities and humanity, including its functions and tasks within human and multispecies communities.

scholarly journals Latin America through the vision of environmental geopolitics. A little about the history of the issue

2020 ◽  
Vol 28 (1) ◽  
pp. 207-236
Author(s):  
Shinkarenko Alexander ◽  
Keyword(s):  
Latin America ◽  
Environmental Problems ◽  
Political Processes ◽  
Current State ◽  
Environmental Discourses ◽  
The World ◽  
History Of

In this article, the author touches upon the formation of ecological geopolitics and the role of Latin America in it. The socio-political processes that are currently taking place in the region focus on environmental problems, as well as the possibility of reducing the intensity of extractivistic initiatives. The relevance of the environmental discourses and the costs generated with the rental model of the economy, is characteristic not only of Latin America, but also other regions of the world. Nevertheless, it is here we can observe the active work of antiextractive movements to form a contemporary environmental agenda and search for models that are alternative to the current state of the world.

scholarly journals Dynamics of mitochondrial inheritance in the evolution of binary mating types and two sexes

2013 ◽  
Vol 280 (1769) ◽  
pp. 20131920 ◽  
Author(s):  
Zena Hadjivasiliou ◽  
Nick Lane ◽  
Robert M. Seymour ◽  
Andrew Pomiankowski
Keyword(s):  
Relative Fitness ◽  
Uniparental Inheritance ◽  
Dependent Manner ◽  
Mating Types ◽  
Mitochondrial Mutation ◽  
Unicellular Eukaryotes ◽  
Fitness Advantage ◽  
Mitochondrial Population ◽  
Fitness Benefits

The uniparental inheritance (UPI) of mitochondria is thought to explain the evolution of two mating types or even true sexes with anisogametes. However, the exact role of UPI is not clearly understood. Here, we develop a new model, which considers the spread of UPI mutants within a biparental inheritance (BPI) population. Our model explicitly considers mitochondrial mutation and selection in parallel with the spread of UPI mutants and self-incompatible mating types. In line with earlier work, we find that UPI improves fitness under mitochondrial mutation accumulation, selfish conflict and mitonuclear coadaptation. However, we find that as UPI increases in the population its relative fitness advantage diminishes in a frequency-dependent manner. The fitness benefits of UPI ‘leak’ into the biparentally reproducing part of the population through successive matings, limiting the spread of UPI. Critically, while this process favours some degree of UPI, it neither leads to the establishment of linked mating types nor the collapse of multiple mating types to two. Only when two mating types exist beforehand can associated UPI mutants spread to fixation under the pressure of high mitochondrial mutation rate, large mitochondrial population size and selfish mutants. Variation in these parameters could account for the range of UPI actually observed in nature, from strict UPI in some Chlamydomonas species to BPI in yeast. We conclude that UPI of mitochondria alone is unlikely to have driven the evolution of two mating types in unicellular eukaryotes.

scholarly journals Positions and prospects of Russian shipbuilding in the world market of naval equipment

2021 ◽  
Vol 92 ◽  
pp. 08007
Author(s):  
Victor Dengov ◽  
Irina Tulyakova ◽  
Elena Gregova
Keyword(s):  
Value Added ◽  
World Market ◽  
External Factors ◽  
Military Equipment ◽  
Current State ◽  
The World ◽  
Military Security ◽  
Available Information ◽  
The Impact

Research background: The products of the arms and military equipment market create the material basis for the country’s military security. The most important segment of this market is the market of naval equipment. The acquired competencies have naturally led Russia to the role of the most important exporter in this market. The authors have repeatedly addressed the topic of Russian shipbuilding and the role of Russia in the world market of naval equipment and military ships. Purpose of the article: The main goal of the research is to analyze the current state of the market of naval equipment, the positions of its main participants and, especially, Russia. To determine the future prospects of Russia’s presence in this market, it was necessary to identify the main problems of Russian shipbuilding and consider the impact of external factors on the state of the industry. Methods: Generalizations of the research are based on processing and systematization of data obtained from available information sources. Analyzing the statistics, the authors were able to deduce the trends of the current moment and determine the prospects. Findings & Value added: The analysis of key market indicators, as well as the problems of Russian shipbuilding, allowed the authors to build possible scenarios for its future development, from optimistic under favorable external factors to pessimistic, in which the loss of not only military security, but also the position of the largest exporter in the world market of naval equipment and military ships is inevitable.

scholarly journals Abundant and diverse Tetrahymena species living in the bladder traps of aquatic carnivorous Utricularia plants

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chao-Yin Cheng ◽  
Shang-Lin Chang ◽  
I-Ting Lin ◽  
Meng-Chao Yao
Keyword(s):  
New Species ◽  
Tetrahymena Thermophila ◽  
Model Organism ◽  
Carnivorous Plant ◽  
Laboratory Model ◽  
Natural Habitats ◽  
Additional Species ◽  
Unicellular Eukaryotes ◽  
Wide Range ◽  
Excellent Candidate

Abstract Ciliates are unicellular eukaryotes known for their cellular complexity and wide range of natural habitats. How they adapt to their niches and what roles they play in ecology remain largely unknown. The genus Tetrahymena is among the best-studied groups of ciliates and one particular species, Tetrahymena thermophila, is a well-known laboratory model organism in cell and molecular biology, making it an excellent candidate for study in protist ecology. Here, based on cytochrome c oxidase subunit I (COX1) gene barcoding, we identify a total of 19 different putative Tetrahymena species and two closely related Glaucoma lineages isolated from distinct natural habitats, of which 13 are new species. These latter include 11 Tetrahymena species found in the bladder traps of Utricularia plants, the most species-rich and widely distributed aquatic carnivorous plant, thus revealing a previously unknown but significant symbiosis of Tetrahymena species living among the microbial community of Utricularia bladder traps. Additional species were collected using an artificial trap method we have developed. We show that diverse Tetrahymena species may live even within the same habitat and that their populations are highly dynamic, suggesting that the diversity and biomass of species worldwide is far greater than currently appreciated.

Creation of walnut (Juglans regia L.) orchards by means of densing fruit-ful vineyards

2020 ◽  
pp. 174-183
Author(s):  
V.M. Kostenko ◽  
◽  
M.F. Kiktenko ◽  
Keyword(s):  
Juglans Regia ◽  
Cost Estimate ◽  
Climatic Zone ◽  
The Internet ◽  
Current State ◽  
Production Experiment ◽  
The World ◽  
The Cost

The profound analysis of the walnut cultivation current state in the world and role of Ukraine in this process is made by the authors V. Kostenko and N. Kiktenko in the paper. The substantiation has been presented of the necessity and opportunities for the areas and gross productions of nuts increasing in Ukraine. That is accounted for by the high profitability level of its production and export potential in the products sales. The cost estimate for creating young walnut stands is demonstrated as well as of managing them. The technology of growing grape hybrid Isabella is described. Weighty argument of lack of prospects end economic inexpediency of its cultivation in Moldova and Ukraine are presented as well as the of cost estimate of planting establishment and growing one hectare of walnut. The natural and climatic zone of the enterprise establishment is described, on the basis of which a production experiment was conducted. This is described in details. The number of treatments against diseases and pests is given. The results are presented of accounting for the yield and income from the vineyard for the period of the researches. The planting plan of the experimental orchard, a hole, scale of fertilizing during planting are described, as well as technological peculiarities of the walnut trees formation in the row of fruiting vineyards. The walnut planting tock assortment is indicated. The results are presented of accounting for the nuts yield by years and cultivars. The authors also described the mycorhiza effects on the development of walnut planting trees and vine bushes. Moreover, the summaries are provided of the videos that were periodically posted on the Internet during the experiment. The recommendations to the producers are also presented.

scholarly journals The role of robots in the improving work of nurses

2019 ◽  
Vol 18 (3) ◽  
pp. 174-182
Author(s):  
Łukasz Blechar ◽  
Patrycja Zalewska
Keyword(s):  
Animal Therapy ◽  
New Developments ◽  
Personal Involvement ◽  
Non Invasive ◽  
Current Trends ◽  
Current State ◽  
The Social ◽  
The World ◽  
Future Of Nursing

AbstractIntroduction. Currently we observe a change in the labor market. It is caused by the new developments in the field of artificial Intelligence.Aim. We would like to present current trends affecting the work of nurses and midwives around the world in order to raise the social awareness of these changes among Polish healthcare workers. Moreover, we want to emphasize the fact that it is necessary to involve them as the stakeholders in the ongoing discussions and research projects in order to better understand their needs and expectations.Discussion. The article revolves around the current state of technology. We begin by outlining the framework of the perceived changes in the nurses’ structures and tasks around the world. Then we provide the examples of a variety of robots already executing those tasks. We start with the robots whose purpose is the elimination of simple, routine activities such as TUG or HOMER. After doing so, we move on to possible solutions how to eliminate the need for personal involvement in invasive (such as BloodBot) and non-invasive procedures (CLARA). We finish by introducing the machines used to replicate animal therapy, which can be used to treat patients who have difficulties with communicating their needs.Conclusions. We would like to present the future of nursing closely related to machines. We want to emphasize the element of complementarity of this relation and the fact that performing some tasks by robots is not connected with replacing people, but rather with enabling them to shift their focus from the performance of arduous duties to spending more time on empathic work with the patient.

scholarly journals Molecular Characterization, Protein-protein Interaction Network, and Evolution of four Glutathione Peroxidases from Tetrahymena Thermophila

2020 ◽  
Author(s):  
Diana Ferro ◽  
Rigers Bakiu ◽  
Sandra Pucciarelli ◽  
Cristina Miceli ◽  
Adriana Vallesi ◽  
...  
Keyword(s):  
Time Course ◽  
Tetrahymena Thermophila ◽  
Model Organism ◽  
Interaction Network ◽  
Regulatory Elements ◽  
Integrative Approach ◽  
Gene Characterization ◽  
Functional Relationships ◽  
Glutathione Peroxidases

Glutathione peroxidases (GPxs) form a broad family of antioxidant proteins essential for maintaining redox homeostasis in eukaryotic cells. In this study, we used an integrative approach that combines bioinformatics, molecular biology, and biochemistry to investigate the role of GPxs in reactive oxygen species detoxification in the unicellular eukaryotic model organism Tetrahymena thermophila. Both phylogenetic and mechanistic empirical model analyses provided indications about the evolutionary relationships among the GPXs of Tetrahymena and the orthologous enzymes of phylogenetically related species. In-silico gene characterization and text mining were used to predict the functional relationships between GPxs and other physiologically-relevant processes. The GPx genes contain conserved transcriptional regulatory elements in the promoter region, which suggest that transcription is under tight control of specialized signaling pathways. The bioinformatic findings were next experimentally validated by studying the time course of copper (Cu)-dependent regulation of gene transcription and enzymatic activity. Results emphasize the role of GPxs in the detoxification pathways that, by complex regulation of Cu-dependent GPx gene expression, enables Tetrahymena to survive in high Cu concentrations and the associated redox environment.

scholarly journals An Overview of the Current State of Human Issues in Horticulture in the United States

2000 ◽  
Vol 10 (1) ◽  
pp. 27-33 ◽  
Author(s):  
Virginia I. Lohr ◽  
Paula Diane Relf
Keyword(s):  
Social Sciences ◽  
United States ◽  
Well Being ◽  
The United States ◽  
Public Gardens ◽  
Current State ◽  
The Social ◽  
The World ◽  
Plant Sciences

Throughout history, plants have been used to benefit people. In the United States, formal research to document the impacts of plants on people was not published until the 1970s, when papers from social and medical scientists began to appear. In the 1990s, symposia, including the first on “The Role of Horticulture in Human Well-being and Social Development,” brought people together from around the world to share and expand their knowledge in this emerging field. Symposium participants have included researchers in the social sciences and plant sciences, practitioners in horticultural therapy, teachers in colleges and public gardens, industry representatives applying the knowledge, and more. This has formed the basis for current activities in research, teaching, and practice throughout the United States. Examples from research that now documents a variety of beneficial impacts of plants on people are discussed.

scholarly journals Role of Information Science in Sustainable Development: Sierra Leone as a Case Study

2015 ◽  
Vol 7 (2) ◽  
pp. 23-29
Author(s):  
Emerson Abraham Jackson
Keyword(s):  
Information Science ◽  
Green Economy ◽  
Critical Approach ◽  
Electronic Money ◽  
Resource Potential ◽  
Current State ◽  
The World ◽  
Money Transfer

Abstract IS / ICT is dictating the world in terms of service provision, and more so in education and the financial sector such as electronic money transfer. The article has provided a review of Information Science (IS) in the light of its wider interpretation in different walks of life. The current state of IS / ICT provision is also addressed, with the need to focusing attention in improving the country's capacity in meeting global demand for services. Qualitative interpretation of themes was used in helping to provide critical approach in unravelling issues for the good of the nation. Recommendations pointed to an enhancement in the infrastructural capacity, and also human resources to address on-going demands. IS / ICT capacity around the world is changing and so too is the need for the country to build on its human resource potential to address threats posed, from within and outside of the country, while at the same time focusing attention in enhancing the green economy.

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