scholarly journals Identification and Assessment of Plasmodium berghei Merozoites and Cell Cycle by Flow Cytometry

2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 108-115
Author(s):  
Qigui Li ◽  
Lisa H Xie ◽  
Jing Zhang ◽  
Brandon S Pybus
Keyword(s):  
Flow Cytometry ◽  
Life Cycle ◽  
Light Microscopy ◽  
Plasmodium Berghei ◽  
Life Stage ◽  
Fluorescent Microscopy ◽  
Life Cycle Stage ◽  
Blood Stage ◽  
Malaria Therapy ◽  
Complete Life Cycle

ABSTRACT Background The asexual blood stages of the Plasmodium berghei life cycle including merozoites are attractive targets for transmission blocking vaccines and drugs. Improved understanding of P. berghei life cycle stage growth and development would provide new opportunities to evaluate antimalarial vaccines and drugs. Methods Blood stage samples from C57BL/6 albino mice infected with P. berghei sporozoites were singly stained with a high binding affinity deoxyribonucleic acid dye, YOYO-1, and measured by flow cytometry (FCM). Duplicate slides were made from samples and stained with diluted Giemsa’s and YOYO-1, respectively. Correlated results were compared by FCM, light microscopy, and fluorescent microscopy. Results Complete life cycle stage determination and analysis by FCM is reported to include merozoites, ring forms, trophozoites, immature, and mature schizonts. FCM demonstrated a clear separation between each stage using their unique fluorescence distribution. When compared to light microscopy, a strong correlation (r 2 = 0.925 to 0.974) was observed in determining the ring forms, trophozoites, and schizonts phases, but only a moderate correlation (r 2 = 0.684 to 0.778) was observed for merozoites. The identification and measurement of merozoites suggest that FCM is a useful technique to monitor the entire life stage of the parasite. Initial stage-specific data demonstrated that mefloquine has a mode of action on mature parasite forms, and artesunic acid was rapidly effective against merozoites and other immature and mature parasite forms with higher killing. Conclusion Blood stage parasites in each individual life stage, including merozoites, are reliably identified and quantified quickly by FCM, making this technique an ideal alternative to microscopy. This integrated whole life stage model, particularly with confirmed determination of merozoite population, could widely be used for drug and vaccine research in malaria therapy and prophylaxis.

scholarly journals Reuse of bituminous pavements: A mini-review of research, regulations and modelling

2016 ◽  
Vol 35 (4) ◽  
pp. 357-366 ◽  
Author(s):  
Joke Anthonissen ◽  
Wim Van den bergh ◽  
Johan Braet
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
End Of Life ◽  
Asphalt Pavement ◽  
Life Stage ◽  
Life Cycle Stage ◽  
Supplementary Information ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt ◽  
Bituminous Mixtures

Bituminous pavement can be recycled – even multiple times – by reusing it in new bituminous mixtures. If the mechanical properties of the binder get worse, this reclaimed asphalt is often used in the sub-structure of the road. Apparently, up till now, no end-of-life phase exists for the material. Actually, defining the end-of-life and the end-of-waste stage of a material is important for life cycle assessment modelling. Various standards and scientific studies on modelling life cycle assessment are known, but the crucial stages are not yet defined for reclaimed asphalt pavement. Unlike for iron, steel and aluminium scrap, at this moment, no legislative end-of-waste criteria for aggregates are formulated by the European Commission. More research is necessary in order to develop valuable end-of-life criteria for aggregates. This contribution is a mini-review article of the current regulations, standards and studies concerning end-of-life and end-of-waste of reclaimed asphalt pavement. The existing methodology in order to define end-of-waste criteria, a case study on aggregates and the argumentation used in finished legislative criteria are the basis to clarify some modelling issues for reclaimed asphalt material. Hence, this contribution elucidates the assignment of process environmental impacts to a life cycle stage as defined by EN15804, that is, end-of-life stage (C) and the supplementary information Module D with benefits and loads beyond the system boundary.

scholarly journals Total Life Cycle of Polypropylene Products: Reducing Environmental Impacts in the Manufacturing Phase

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1901
Author(s):  
Viktoria Mannheim ◽  
Zoltan Simenfalvi
Keyword(s):  
Life Cycle ◽  
Environmental Impact ◽  
End Of Life ◽  
Injection Moulding ◽  
Life Stage ◽  
Raw Material ◽  
Production Phase ◽  
Complete Life Cycle ◽  
Injection Moulding Process ◽  
Total Life

This paper assesses the environmental burdens of a polypropylene product throughout the product’s life cycle, especially focusing on the injection-moulding stage. The complete life cycle model of the polypropylene product has been developed from the raw material extraction and production phase through its usage to the end-of-life stage with the help of the life cycle assessment method. To find the answers to the posed problems, different impacts were analysed by GaBi 8.0 software. The analysis lasted from the cradle to the grave, expanding the analysis of the looping method. The aim of the research was to determine the energy and material resources, emissions, and environmental impact indicators. Basically, the article tried to answer three questions: (1) How can we optimize the production phase for the looping method? (2) Which materials and streams are recyclable in the design of the production process? (3) What is the relationship between life cycle stages and total life cycle of the product? As we inspect the life cycle of the product, the load on the environment was distributed as follows: 91% in the production phase, 3% in the use phase, and 6% in the end-of-life phase. The results of the research can be used to develop technologies, especially the injection-moulding process, with a lower environmental impact.

scholarly journals Predicting the effects of climate change on freshwater cyanobacterial blooms requires consideration of the complete cyanobacterial life cycle

2020 ◽  
Author(s):  
Kathryn L Cottingham ◽  
Kathleen C Weathers ◽  
Holly A Ewing ◽  
Meredith L Greer ◽  
Cayelan C Carey
Keyword(s):  
Climate Change ◽  
Life Cycle ◽  
Climate Models ◽  
Empirical Studies ◽  
Life Stage ◽  
Cyanobacterial Blooms ◽  
Life Stages ◽  
Ecosystem Models ◽  
Complete Life Cycle ◽  
Integrated Research

Abstract To date, most research on cyanobacterial blooms in freshwater lakes has focused on the pelagic life stage. However, examining the complete cyanobacterial life cycle—including benthic life stages—may be needed to accurately predict future bloom dynamics. The current expectation, derived from the pelagic life stage, is that blooms will continue to increase due to the warmer temperatures and stronger stratification associated with climate change. However, stratification and mixing have contrasting effects on different life stages: while pelagic cyanobacteria benefit from strong stratification and are adversely affected by mixing, benthic stages can benefit from increased mixing. The net effects of these potentially counteracting processes are not yet known, since most aquatic ecosystem models do not incorporate benthic stages and few empirical studies have tracked the complete life cycle over multiple years. Moreover, for many regions, climate models project both stronger stratification and increased storm-induced mixing in the coming decades; the net effects of those physical processes, even on the pelagic life stage, are not yet understood. We therefore recommend an integrated research agenda to study the dual effects of stratification and mixing on the complete cyanobacterial life cycle—both benthic and pelagic stages—using models, field observations and experiments.

A Plasmodium berghei reference line that constitutively expresses GFP at a high level throughout the complete life cycle

2004 ◽  
Vol 137 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Blandine Franke-Fayard ◽  
Holly Trueman ◽  
Jai Ramesar ◽  
Jacqui Mendoza ◽  
Maarten van der Keur ◽  
...  
Keyword(s):  
Life Cycle ◽  
Plasmodium Berghei ◽  
Reference Line ◽  
Complete Life Cycle ◽  
High Level

scholarly journals Using the Boston Matrix at Identification of the Corporate Life Cycle Stage

2015 ◽  
Vol 63 (1) ◽  
pp. 235-243 ◽  
Author(s):  
Zdeněk Konečný ◽  
Marek Zinecker
Keyword(s):  
Life Cycle ◽  
Product Life Cycle ◽  
Life Stage ◽  
Life Cycle Stage ◽  
Economic Cycle ◽  
New Model ◽  
Market Shares ◽  
Corporate Life Cycle ◽  
The Individual ◽  
The Impact

The main aim of this article is to develop a new model supporting the identification of the particular corporate life stage within the corporate life cycle. This model will be derived from the Boston matrix. The main reason for using this approach as the base for making new model of the corporate life cycle is the fact, that every quadrant of the Boston matrix can be assigned to one phase of the product life cycle and there is supposed, that the phase, in which are most products, determines the phase of the corporate life cycle. For application the Boston matrix by identification phases of the corporate life cycle is necessary to define low and high values of both its variables using some quantities from the model of corporate- and market life cycle by Reiners (2004). So the interval of low and high sales growth is determined by comparing sales of the company and sales of the market and furthermore, there is considered the rate of inflation to eliminate the impact of price changes. And for determination low and high market shares, there are compared the shares of sales and shares of total assets. After that, there will be possible to identify all the quadrants and thus all the individual phases unequivocally, which is the basic advantage compared to most existing models of the corporate life cycle. The following aim of this article is to compare the occurrence of individual phases, identified by this modified model, depending on the sector sensitivity to the economic cycle, measured by the coefficient of correlation between sales on the market and GDP. There are selected two sectors of the Czech economy, namely one cyclical and one neutral sector. Subsequently there is selected a sample of companies from both these sectors. The data are collected from financial statements of companies and from analytical materials by the Czech Ministry of Industry and Trade and by the Czech Statistical Office. On the basis of this research, there were recorded differences especially in the number of companies in the phases of stabilisation and decline, depending on the sector sensitivity to the economic cycle.

scholarly journals End-of-life modelling of buildings to support more informed decisions towards achieving circular economy targets

2020 ◽  
Vol 25 (11) ◽  
pp. 2122-2139 ◽  
Author(s):  
Sahar Mirzaie ◽  
Mihaela Thuring ◽  
Karen Allacker
Keyword(s):  
Life Cycle ◽  
End Of Life ◽  
Circular Economy ◽  
Life Stage ◽  
Life Cycle Stage ◽  
Construction Sector ◽  
Quality Factors ◽  
Product Environmental Footprint ◽  
Allocation Approach

Abstract Purpose Life cycle assessment (LCA) is an internationally accepted method to assess the environmental impacts of buildings. A major methodological challenge remains the modelling of the end-of-life stage of buildings and allocation of benefits and burdens between systems. Various approaches are hence applied in practice to date. This paper compares the two methods widely renowned in Europe—the EC product environmental footprint (PEF) method and the CEN standards: EN 15804+A1 and EN15978—and offers insights about their fitness for achieving circularity goals. Methods The EC PEF method and the CEN EN 15804/EN 15978 standards were methodologically analysed with a focus on the end-of-life modelling and allocation approach and were applied to a building case study. The EN 15804+A1 standard explains the guidelines but does not offer a modelling formula. Accordingly, this paper proposes a formula for the CEN standards using identical parameters as in the end-of-life circular footprint formula (CFF) of the EC PEF Guidance v6.3 to increase consistency among LCA studies. The calculation formulas were then applied to a newly constructed office building. A comparative analysis of both the implementation and results are described, and recommendations are formulated. Results In the absence of databases compatible with the two LCA methods and comprising all building products, the Ecoinvent datasets had to be remodelled to enable a comparative modular assessment. This proved to be a laborious process. The EC PEF method and CEN standards showed similar impacts and hotspots for the case study building. The module D in the CEN standards includes a significant share of positive impacts, but due to collective accounting, it does not clearly communicate these benefits. The summation of burdens and benefits in the EC PEF method reduces its transparency, while the allocation and quality factors enable this method to better capture the market realities and drive circular economy goals. Conclusions The construction sector and the LCI database developers are encouraged to create the missing LCA databases compatible with the modular and end-of-life allocation modelling requirements of both methods. More prescriptive and meticulous guidelines, with further harmonization between the EC PEF method and the CEN standards and their end-of-life allocation formula, would largely increase comparability and reliability of LCA studies and communications. To improve transparency, it is recommended to report the module D impacts per life cycle stage as per the CEN standards and the burdens and benefits separately for each life cycle stage as per the EC PEF method.

Eratum to “A Plasmodium berghei reference line that constitutively expresses GFP at a high level throughout the complete life cycle”

2004 ◽  
Vol 137 (2) ◽  
pp. 365-367 ◽  
Author(s):  
Blandine Franke-Fayard ◽  
Holly Trueman ◽  
Jai Ramesar ◽  
Jacqui Mendoza ◽  
Maarten van der Keur ◽  
...  
Keyword(s):  
Life Cycle ◽  
Plasmodium Berghei ◽  
Reference Line ◽  
Complete Life Cycle ◽  
High Level

scholarly journals Life Cycle Effects on the Vertical Structure of Precipitation in East China Measured by Himawari-8 and GPM DPR

2018 ◽  
Vol 146 (7) ◽  
pp. 2183-2199 ◽  
Author(s):  
Aoqi Zhang ◽  
Yunfei Fu
Keyword(s):  
Life Cycle ◽  
Brightness Temperature ◽  
Vertical Structure ◽  
Life Stage ◽  
Life Cycle Stage ◽  
Precipitation Event ◽  
Mature Stage ◽  
Life Stages ◽  
Dual Frequency ◽  
Cloud Water Content

Abstract We identified precipitating systems from May to August 2016 using data from the Global Precipitation Measurement mission Dual-frequency Precipitation Radar instrument. Then, using this set of cases, Himawari-8 10.4-μm brightness temperature data from before and after each precipitation event were used to identify three life stages of clouds: a developing stage, a mature stage, and a dissipating stage. Using statistical analysis and two case studies, we show that the precipitating systems at different life stages of the clouds have different systematic properties, including the area of precipitation, the convective ratio, the rain-top height, and the brightness temperature. The developing systems had the largest convective ratio, whereas the dissipating systems had the largest area of precipitation. The life stage of the cloud also influenced the vertical structure of the precipitation. The microphysical processes within each stage were unique, leading to various properties of the droplets in precipitation. The developing systems had large, but sparse, droplets; the mature systems had large and dense droplets; and the dissipating systems had small and sparse droplets. Our results suggest that the different properties of precipitating systems in each life cycle stage of clouds are linked to the cloud water content and the upward motion of air.

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