scholarly journals The Aseptic Culture of Arabidopsis Thaliana (l.) Heynh.

1957 ◽  
Vol 10 (3) ◽  
pp. 243 ◽  
Author(s):  
J Langridge

Arabidopsis thaliana (L.) Heynh. is a small, rapidly growing crucifer with a 28-day life cycle, a low chromosome number (n=5), and a high fertility (152�1l seeds under aseptic conditions). The small size and rapid growth of the plants enable them to be grown throughout their life cycles on sterile, nutrient agar in ordinary' test tubes. Alternatively, up to 50 plants may be grown on silica gel in crystallizing dishes. For optimal growth the trace element cations should be chelated and light should be excluded from the roots. When supplied with sucrose the plants absorb only the glucose portion. During growth the plants excrete small quantities of vitamins and other substances into the medium but not in amounts likely to prevent the detection of growth mutants through cross-feeding.

2020 ◽  
Vol 1 (10) ◽  
pp. 26-35
Author(s):  
E. A. SHUBINA ◽  
◽  
Yu. A. KOMAROVSKY ◽  
A. V. MERKUSHEV ◽  
◽  
...  

The article is devoted to the study of the largest mergers and acquisitions (M&A, “Mergers & Acquisitions”) in Russia for 2017–2019. (the acquired block of shares is not less than 99%). The concept of life cycles of organizations and theoretical aspects of mergers and acquisitions are described. The stages of the life cycle of the merged and reorganized companies, the goals of mergers and acquisitions, depending on the stages of the life cycle are analyzed.


Author(s):  
Valeriy S. Gerasimov ◽  
Vladimir I. Ignatov ◽  
Konstantin G. Sovin

According to forecasts for 2022, the number of self-propelled agricultural machinery that will fail will be about 100 thousand units. This will have a significant impact on the overall productivity in the field of agricultural production and will require additional financial costs for effective resource-saving environmental-oriented utilization of agricultural machinery with the maximum recovery of secondary resources in the processing of its components. (Research purpose) The research purpose is considering the main life cycles of machinery, including agricultural, and determining the possibility of obtaining secondary resources in the recycling of components of machinery and equipment. (Materials and methods) The authors found that the establishment of an industry-wide recycling system would allow the reuse of usable and recovered parts obtained from decommissioned equipment, as well as receive additional funding from the sale of secondary resources. The authors have found that for the functioning of the whole system, it is necessary to work with a large amount of data related to the ongoing recycling processes, as well as constantly monitor changes in the state and properties of materials. They also found that the maximum use of digital technology is the only way to combine all these requirements and make the system work. (Results and discussion) The article reviews the key points of the use of life cycle method for equipment, including agricultural, reviews the state of machine and tractor park of agro-industrial complex, shows the possibility of using resource-saving ecologically oriented branch system of recycling of agricultural machinery, as well as the movement of waste and material flows in the processing components of utilized machines. (Conclusion) The article presents recommendations on the possibility of efficient disposal of equipment, including agricultural, with the maximum recovery of secondary resources from recycled waste.


2020 ◽  
Vol 40 (6) ◽  
pp. 825-832 ◽  
Author(s):  
Miku Yabuta ◽  
Jens T Høeg ◽  
Shigeyuki Yamato ◽  
Yoichi Yusa

Abstract Although parasitic castration is widespread among rhizocephalan barnacles, Boschmaella japonica Deichmann & Høeg, 1990 does not completely sterilise the host barnacle Chthamalus challengeri Hoek, 1883. As little information is available on the relationships with the host in “barnacle-infesting parasitic barnacles” (family Chthamalophilidae), we studied the life cycles of both B. japonica and C. challengeri and the effects of the parasite on the host reproduction. Specimens of C. challengeri were collected from an upper intertidal shore at Shirahama, Wakayama, western Japan from April 2017 to September 2018 at 1–3 mo intervals. We recorded the body size, number of eggs, egg volume, and the presence of the parasite for each host. Moreover, settlement and growth of C. challengeri were followed in two fixed quadrats. Chthamalus challengeri brooded from February to June. The prevalence of B. japonica was high (often exceeded 10%) from April to July, and was rarely observed from September to next spring. The life cycle of the parasite matched well with that of the host. The parasite reduced the host’s brooding rate and brood size, to the extent that no hosts brooded in 2018.


2021 ◽  
Vol 13 (10) ◽  
pp. 5726
Author(s):  
Aleksandra Wewer ◽  
Pinar Bilge ◽  
Franz Dietrich

Electromobility is a new approach to the reduction of CO2 emissions and the deceleration of global warming. Its environmental impacts are often compared to traditional mobility solutions based on gasoline or diesel engines. The comparison pertains mostly to the single life cycle of a battery. The impact of multiple life cycles remains an important, and yet unanswered, question. The aim of this paper is to demonstrate advances of 2nd life applications for lithium ion batteries from electric vehicles based on their energy demand. Therefore, it highlights the limitations of a conventional life cycle analysis (LCA) and presents a supplementary method of analysis by providing the design and results of a meta study on the environmental impact of lithium ion batteries. The study focuses on energy demand, and investigates its total impact for different cases considering 2nd life applications such as (C1) material recycling, (C2) repurposing and (C3) reuse. Required reprocessing methods such as remanufacturing of batteries lie at the basis of these 2nd life applications. Batteries are used in their 2nd lives for stationary energy storage (C2, repurpose) and electric vehicles (C3, reuse). The study results confirm that both of these 2nd life applications require less energy than the recycling of batteries at the end of their first life and the production of new batteries. The paper concludes by identifying future research areas in order to generate precise forecasts for 2nd life applications and their industrial dissemination.


2021 ◽  
Author(s):  
Keiko U Torii

Abstract Background Stomata are adjustable pores on the surface of plant shoots for efficient gas exchange and water control. The presence of stomata is essential for plant growth and survival, and the evolution of stomata is considered as a key developmental innovation of the land plants, allowing colonization on land from aquatic environments some 450 million years ago. In the past two decades, molecular genetic studies using the model plant Arabidopsis thaliana identified key genes and signalling modules that regulate stomatal development: master-regulatory transcription factors that orchestrate cell-state transitions and peptide-receptor signal transduction pathways, which, together, enforce proper patterning of stomata within the epidermis. Studies in diverse plant species, ranging from bryophytes to angiosperm grasses, have begun to unravel the conservation and uniqueness of the core modules in stomatal development. Scope Here, I review the mechanisms of stomatal development in the context of epidermal tissue patterning. First, I introduce the core regulatory mechanisms of stomatal patterning and differentiation in the model species Arabidopsis thaliana. Subsequently, experimental evidence is presented supporting the idea that different cell types within the leaf epidermis, namely stomata, hydathodes pores, pavement cells, and trichomes, either share developmental origins or mutually influence each other’s gene regulatory circuits during development. Emphasis is taken on extrinsic and intrinsic signals regulating the balance between stomata and pavement cells, specifically by controlling the fate of Stomatal-Lineage Ground Cells (SLGCs) to remain within the stomatal-cell lineage or differentiate into pavement cells. Finally, I discuss the influence of inter-tissue-layer communication between the epidermis and underlying mesophyll/vascular tissues on stomatal differentiation. Understanding the dynamic behaviors of stomatal precursor cells and their differentiation in the broader context of tissue and organ development may help design plants tailored for optimal growth and productivity in specific agricultural applications and a changing environment.


2021 ◽  
Vol 22 (6) ◽  
pp. 3068
Author(s):  
Zaira M. López-Juárez ◽  
Laura Aguilar-Henonin ◽  
Plinio Guzmán

RNA-binding proteins (RBPs) are key elements involved in post-transcriptional regulation. Ataxin-2 (ATXN2) is an evolutionarily conserved RBP protein, whose function has been studied in several model organisms, from Saccharomyces cerevisiae to the Homo sapiens. ATXN2 interacts with poly(A) binding proteins (PABP) and binds to specific sequences at the 3′UTR of target mRNAs to stabilize them. CTC-Interacting Domain3 (CID3) and CID4 are two ATXN2 orthologs present in plant genomes whose function is unknown. In the present study, phenotypical and transcriptome profiling were used to examine the role of CID3 and CID4 in Arabidopsis thaliana. We found that they act redundantly to influence pathways throughout the life cycle. cid3cid4 double mutant showed a delay in flowering time and a reduced rosette size. Transcriptome profiling revealed that key factors that promote floral transition and floral meristem identity were downregulated in cid3cid4 whereas the flowering repressor FLOWERING LOCUS C (FLC) was upregulated. Expression of key factors in the photoperiodic regulation of flowering and circadian clock pathways, were also altered in cid3cid4, as well as the expression of several transcription factors and miRNAs encoding genes involved in leaf growth dynamics. These findings reveal that ATXN2 orthologs may have a role in developmental pathways throughout the life cycle of plants.


2021 ◽  
Vol 13 (5) ◽  
pp. 2525
Author(s):  
Camila López-Eccher ◽  
Elizabeth Garrido-Ramírez ◽  
Iván Franchi-Arzola ◽  
Edmundo Muñoz

The aim of this study is to assess the environmental impacts of household life cycles in Santiago, Chile, by household income level. The assessment considered scenarios associated with environmental policies. The life cycle assessment was cradle-to-grave, and the functional unit considered all the materials and energy required to meet an inhabitant’s needs for one year (1 inh/year). Using SimaPro 9.1 software, the Recipe Midpoint (H) methodology was used. The impact categories selected were global warming, fine particulate matter formation, terrestrial acidification, freshwater eutrophication, freshwater ecotoxicity, mineral resource scarcity, and fossil resource scarcity. The inventory was carried out through the application of 300 household surveys and secondary information. The main environmental sources of households were determined to be food consumption, transport, and electricity. Food consumption is the main source, responsible for 33% of the environmental impacts on global warming, 69% on terrestrial acidification, and 29% on freshwater eutrophication. The second most crucial environmental hotspot is private transport, whose contribution to environmental impact increases as household income rises, while public transport impact increases in the opposite direction. In this sense, both positive and negative environmental effects can be generated by policies. Therefore, life-cycle environmental impacts, the synergy between policies, and households’ socio-economic characteristics must be considered in public policy planning and consumer decisions.


1992 ◽  
Vol 12 (9) ◽  
pp. 3827-3833 ◽  
Author(s):  
T H Adams ◽  
W A Hide ◽  
L N Yager ◽  
B N Lee

In contrast to many other cases in microbial development, Aspergillus nidulans conidiophore production initiates primarily as a programmed part of the life cycle rather than as a response to nutrient deprivation. Mutations in the acoD locus result in "fluffy" colonies that appear to grow faster than the wild type and proliferate as undifferentiated masses of vegetative cells. We show that unlike wild-type strains, acoD deletion mutants are unable to make conidiophores under optimal growth conditions but can be induced to conidiate when growth is nutritionally limited. The requirement for acoD in conidiophore development occurs prior to activation of brlA, a primary regulator of development. The acoD transcript is present both in vegetative hyphae prior to developmental induction and in developing cultures. However, the effects of acoD mutations are detectable only after developmental induction. We propose that acoD activity is primarily controlled at the posttranscriptional level and that it is required to direct developmentally specific changes that bring about growth inhibition and activation of brlA expression to result in conidiophore development.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Mikas Ilgūnas ◽  
Carolina Romeiro Fernandes Chagas ◽  
Dovilė Bukauskaitė ◽  
Rasa Bernotienė ◽  
Tatjana Iezhova ◽  
...  

Abstract Background Haemoproteus parasites (Haemosporida, Haemoproteidae) are cosmopolitan in birds and recent molecular studies indicate enormous genetic diversity of these pathogens, which cause diseases in non-adapted avian hosts. However, life-cycles remain unknown for the majority of Haemoproteus species. Information on their exoerythrocytic development is particularly fragmental and controversial. This study aimed to gain new knowledge on life-cycle of the widespread blood parasite Haemoproteus majoris. Methods Turdus pilaris and Parus major naturally infected with lineages hPHYBOR04 and hPARUS1 of H. majoris, respectively, were wild-caught and the parasites were identified using microscopic examination of gametocytes and PCR-based testing. Bayesian phylogeny was used to determine relationships between H. majoris lineages. Exoerythrocytic stages (megalomeronts) were reported using histological examination and laser microdissection was applied to isolate single megalomeronts for genetic analysis. Culicoides impunctatus biting midges were experimentally exposed in order to follow sporogonic development of the lineage hPHYBOR04. Results Gametocytes of the lineage hPHYBOR04 are indistinguishable from those of the widespread lineage hPARUS1 of H. majoris, indicating that both of these lineages belong to the H. majoris group. Phylogenetic analysis supported this conclusion. Sporogony of the lineage hPHYBOR04 was completed in C. impunctatus biting midges. Morphologically similar megalomeronts were reported in internal organs of both avian hosts. These were big roundish bodies (up to 360 μm in diameter) surrounded by a thick capsule-like wall and containing irregularly shaped cytomeres, in which numerous merozoites developed. DNA sequences obtained from single isolated megalomeronts confirmed the identification of H. majoris. Conclusions Phylogenetic analysis identified a group of closely related H. majoris lineages, two of which are characterized not only by morphologically identical blood stages, but also complete sporogonic development in C. impunctatus and development of morphologically similar megalomeronts. It is probable that other lineages belonging to the same group would bear the same characters and phylogenies based on partial cytb gene could be used to predict life-cycle features in avian haemoproteids including vector identity and patterns of exoerythrocytic merogony. This study reports morphologically unique megalomeronts in naturally infected birds and calls for research on exoerythrocytic development of haemoproteids to better understand pathologies caused in avian hosts.


Author(s):  
YASUSHI UMEDA ◽  
AKIRA NONOMURA ◽  
TETSUO TOMIYAMA

Environmental issues require a new manufacturing paradigm because the current mass production and mass consumption paradigm inevitably cause them. We have already proposed a new manufacturing paradigm called the “Post Mass Production Paradigm (PMPP)” that advocates sustainable production by decoupling economic growth from material and energy consumption. To realize PMPP, appropriate planning of a product life cycle (design of life cycle) is indispensable in addition to the traditional environmental conscious design methodologies. For supporting the design of a life cycle, this paper proposes a life-cycle simulation system that consists of a life-cycle simulator, an optimizer, a model editor, and knowledge bases. The simulation system evaluates product life cycles from an integrated view of environmental consciousness and economic profitability and optimizes the life cycles. A case study with the simulation system illustrates that the environmental impacts can be reduced drastically without decreasing corporate profits by appropriately combining maintenance, reuse and recycling, and by taking into consideration that optimized modular structures differ according to life-cycle options.


Sign in / Sign up

Export Citation Format

Share Document