scholarly journals Modeling host-associating microbes under selection

2021 ◽  
Author(s):  
Florence Bansept ◽  
Nancy Obeng ◽  
Hinrich Schulenburg ◽  
Arne Traulsen
Keyword(s):  
Life Cycle ◽  
Selection Pressure ◽  
External Environment ◽  
Initial Distribution ◽  
Life Cycles ◽  
Phenotypic Traits ◽  
Replication Rate ◽  
Selection Gradient ◽  
Migration Rates ◽  
Intensity Of Competition

AbstractThe concept of fitness is often reduced to a single component, such as the replication rate in a given habitat. For species with multi-step life cycles, this can be an unjustified oversimplification, as every step of the life cycle can contribute to the overall reproductive success in a specific way. In particular, this applies to microbes that spend part of their life cycles associated to a host. In this case, there is a selection pressure not only on the replication rates, but also on the phenotypic traits associated to migrating from the external environment to the host and vice-versa (i.e., the migration rates). Here, we investigate a simple model of a microbial lineage living, replicating, migrating and competing in and between two compartments: a host and an environment. We perform a sensitivity analysis on the overall growth rate to determine the selection gradient experienced by the microbial lineage. We focus on the direction of selection at each point of the phenotypic space, defining an optimal way for the microbial lineage to increase its fitness. We show that microbes can adapt to the two-compartment life cycle through either changes in replication or migration rates, depending on the initial values of the traits, the initial distribution across the two compartments, the intensity of competition, and the time scales involved in the life cycle versus the time scale of adaptation (which determines the adequate probing time to measure fitness). Overall, our model provides a conceptual framework to study the selection on microbes experiencing a host-associated life cycle.

scholarly journals Modeling host-associating microbes under selection

2021 ◽  
Author(s):  
Florence Bansept ◽  
Nancy Obeng ◽  
Hinrich Schulenburg ◽  
Arne Traulsen
Keyword(s):  
Life Cycle ◽  
Microbial Population ◽  
Initial Distribution ◽  
Life Cycles ◽  
Phenotypic Traits ◽  
Complex Life Cycles ◽  
Selection Gradient ◽  
Migration Rates ◽  
Intensity Of Competition ◽  
Global Growth

The concept of fitness is often reduced to a single component, such as the replication rate in a given habitat. For species with complex life cycles, this can be an unjustified oversimplification, as every step of the life cycle can contribute to reproductive success in a specific way. In particular, this applies to microbes that spend part of their life cycles associated to a host, i.e. in a microbiota. In this case, there is a selection pressure not only on the replication rates, but also on the phenotypic traits associated to migrating from the external environment to the host and vice-versa. Here, we investigate a simple model of a microbial population living, replicating, migrating and competing in and between two compartments: a host and its environment. We perform a sensitivity analysis on the global growth rate to determine the selection gradient experienced by the microbial population. We focus on the direction of selection at each point of the phenotypic space, defining an optimal way for the microbial population to increase its fitness. We show that microbes can adapt to the two-compartment life cycle through either changes in replication or migration rates, depending on the initial values of the traits, the initial distribution of the population across the compartments, the intensity of competition, and the time scales involved in the life cycle versus the time scale of adaptation (which determines the adequate probing time to measure fitness). Overall, our model provides a conceptual framework to study the selection on microbes experiencing a host-associated life cycle.

MERGERS AND ACQUISITIONS AND THEIR CORRELATION WITH THE LIFE CYCLES OF MEMBER COMPANIES ON THE EXAMPLE OF THE RUSSIAN MARKET 2017–2019

2020 ◽  
Vol 1 (10) ◽  
pp. 26-35
Author(s):  
E. A. SHUBINA ◽  
◽  
Yu. A. KOMAROVSKY ◽  
A. V. MERKUSHEV ◽  
◽  
...  
Keyword(s):  
Life Cycle ◽  
Mergers And Acquisitions ◽  
Life Cycles ◽  
Russian Market

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.

Life cycle of self-propelled machinery with waste generation at its disposal

2020 ◽  
pp. 28-35
Author(s):  
Valeriy S. Gerasimov ◽  
Vladimir I. Ignatov ◽  
Konstantin G. Sovin
Keyword(s):  
Life Cycle ◽  
Life Cycles ◽  
The State ◽  
Research Purpose ◽  
Industrial Complex ◽  
Agricultural Machinery ◽  
Resource Saving ◽  
Secondary Resources ◽  
Branch System ◽  
Additional Funding

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.

Metabolism, homeostasis and growth

2017 ◽  
Author(s):  
Derek Burton ◽  
Margaret Burton
Keyword(s):  
Energy Storage ◽  
White Muscle ◽  
External Environment ◽  
Life Cycles ◽  
Fish Growth ◽  
Chloride Cells ◽  
Internal Environment ◽  
Ion Regulation ◽  
Yolk Proteins ◽  
Active Substances

Metabolism consists of the sum of anabolism (construction) and catabolism (destruction) with the release of energy, and achieving a fairly constant internal environment (homeostasis). The aquatic external environment favours differences from mammalian pathways of excretion and requires osmoregulatory adjustments for fresh water and seawater though some taxa, notably marine elasmobranchs, avoid osmoregulatory problems by retaining osmotically active substances such as urea, and molecules protecting tissues from urea damage. Ion regulation may occur through chloride cells of the gills. Most fish are not temperature regulators but a few are regional heterotherms, conserving heat internally. The liver has many roles in metabolism, including in some fish the synthesis of antifreeze seasonally. Maturing females synthesize yolk proteins in the liver. Energy storage may include the liver and, surprisingly, white muscle. Fish growth can be indeterminate and highly variable, with very short (annual) life cycles or extremely long cycles with late and/or intermittent reproduction.

I Feel That! Fluid Dynamics and Sensory Aspects of Larval Settlement across Scales

2018 ◽  
Keyword(s):  
Fluid Dynamics ◽  
Marine Invertebrates ◽  
Larval Settlement ◽  
External Environment ◽  
Life Cycles ◽  
Decision Making Process ◽  
Larval Biology ◽  
Sea Floor ◽  
External Cues ◽  
Juvenile Habitat

A commonality among oceanic life cycles is a process known as settlement, where dispersing propagules transition to the sea floor. For many marine invertebrates, this transition is irreversible, and therefore involves a crucial decision-making process through which larvae evaluate their juvenile habitat-to-be. In this chapter, we consider aspects of the external environment that could influence successful settlement. Specifically, we discuss water flow across scales, and how larvae can engage behaviors to influence where ocean currents take them, and enhance the likelihood of their being carried toward suitable settlement locations. Next, we consider what senses larvae utilize to evaluate their external environment and properly time such behavioral modifications, and settlement generally. We hypothesize that larvae integrate these various external cues in a hierarchical fashion, with differing arrangements being employed across ontogeny and among species. We conclude with a brief discussion of the future promises of larval biology, ecology, and evolution.

Life cycles of the rhizocephalan Boschmaella japonica Deichmann & Høeg, 1990 (Cirripedia: Chthamalophilidae) and its host barnacle Chthamalus challengeri Hoek, 1883 (Cirripedia: Chthamalidae)

2020 ◽  
Vol 40 (6) ◽  
pp. 825-832 ◽  
Author(s):  
Miku Yabuta ◽  
Jens T Høeg ◽  
Shigeyuki Yamato ◽  
Yoichi Yusa
Keyword(s):  
Life Cycle ◽  
Brood Size ◽  
Life Cycles ◽  
The Body ◽  
Egg Volume ◽  
Size Number ◽  
Rhizocephalan Barnacles ◽  
Western Japan ◽  
Upper Intertidal ◽  
Chthamalus Challengeri

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.

scholarly journals Advances of 2nd Life Applications for Lithium Ion Batteries from Electric Vehicles Based on Energy Demand

2021 ◽  
Vol 13 (10) ◽  
pp. 5726
Author(s):  
Aleksandra Wewer ◽  
Pinar Bilge ◽  
Franz Dietrich
Keyword(s):  
Life Cycle ◽  
Lithium Ion Batteries ◽  
Electric Vehicles ◽  
Energy Demand ◽  
Lithium Ion ◽  
Life Cycles ◽  
Future Research ◽  
Research Areas ◽  
Study Results ◽  
The Impact

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.

scholarly journals Life Cycle Assessment of Households in Santiago, Chile: Environmental Hotspots and Policy Analysis

2021 ◽  
Vol 13 (5) ◽  
pp. 2525
Author(s):  
Camila López-Eccher ◽  
Elizabeth Garrido-Ramírez ◽  
Iván Franchi-Arzola ◽  
Edmundo Muñoz
Keyword(s):  
Global Warming ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Environmental Impacts ◽  
Food Consumption ◽  
Household Income ◽  
Resource Scarcity ◽  
Life Cycles ◽  
The Impact ◽  
Freshwater Eutrophication

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.

scholarly journals The life-cycle of the avian haemosporidian parasite Haemoproteus majoris, with emphasis on the exoerythrocytic and sporogonic development

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Mikas Ilgūnas ◽  
Carolina Romeiro Fernandes Chagas ◽  
Dovilė Bukauskaitė ◽  
Rasa Bernotienė ◽  
Tatjana Iezhova ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Life Cycle ◽  
Dna Sequences ◽  
Parus Major ◽  
Life Cycles ◽  
Internal Organs ◽  
Haemosporidian Parasite ◽  
Biting Midges ◽  
Vector Identity ◽  
Bayesian Phylogeny

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.

Study on life-cycle design for the post mass production paradigm

2000 ◽  
Vol 14 (2) ◽  
pp. 149-161 ◽  
Author(s):  
YASUSHI UMEDA ◽  
AKIRA NONOMURA ◽  
TETSUO TOMIYAMA
Keyword(s):  
Life Cycle ◽  
Mass Production ◽  
Product Life Cycle ◽  
Knowledge Bases ◽  
Life Cycles ◽  
Simulation System ◽  
Product Life ◽  
Cycle Simulation ◽  
Life Cycle Design ◽  
Modular Structures

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.

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