scholarly journals Radiotracers for examining biological functions of plants and microbes

2021 ◽  
Author(s):  
◽  
Alexandra Bauer Housh
Keyword(s):  
Carbon Dioxide ◽  
Iron Uptake ◽  
Azospirillum Brasilense ◽  
Light Stimulus ◽  
Light Transmittance ◽  
Enhancement Effect ◽  
Structural Components ◽  
Biological Functions ◽  
The Impact ◽  
Functional Mutants

Tracers are used for qualitative and quantitative investigation of a system. Radiotracers have a radionuclide to observe chemical or biological processes by detection of the radionuclide's decay energy. They are non-disruptive and non-destructive to living systems and can be quantified, imaged, and measured in real time, adding value. This work focuses on radiochemistry and radiotracer techniques to understand maize uptake and localization of micronutrients and the impact of Azospirillum brasilense microbial interactions on these processes. Further, it explored how such interactions can influence stress responses in maize. Finally, it examined how the natural biological functions of A. brasilense bacteria respond to light stimulus conducted through the plant tissues. In this dissertation, the efficacy of using 4-fluorophenylboronic acid (FPBA) as a boton (B) imaging agent, which is a derivative of the B deficiency mimic phenylboronic acid (PBA), was explored. It is shown that radioactively labelled [18F]FPBA (t [subscript 1/2] [equals] 110 m) accumulates at the root tip, the root elongation zone and at lateral root initiation sites in maize roots, and also translocates to the shoot where it accumulates along leaf edges. This is the first time a radiotracer has been utilized to image B in plant systems. Nutritional iron (Fe) content was explored in Azospirillum brasilense associated maize. 59Fe (t [subscript 1/2] [equals] 44.5 d) was used to trace iron uptake kinetics and allocation to leaf. In the presence of functional mutants of this bacteria, iron uptake and allocation to leaf was enhanced in maize seedlings. Maize were grown to maturity and plants associated with the bacteria had greater crop yield (kernels cob-1) and enhanced iron and protein ferritin- the bioavailable form of iron to humans- seed content. Similar studies were completed using zinc (65Zn, t¬Ω= 244 d), where it was noted that the presence of the low-auxin producing and nitrogen-fixing bacteria strain, ipdC, enhanced zinc uptake but had no enhancement effect on allocation or zinc seed filling. Carbon metabolism in response to stresses and microbial interaction was also investigated in maize with [11C]CO2 (t [subscript 1/2] [equals] 20.4 m) radiotracer. In association with A. brasilense, maize fixed more carbon dioxide, allocated more 11C-photosynthates to the roots, and produced more 11C-exudates than control maize. Metabolic differences were studied via radio-HPLC and radio-TLC to reveal association enhanced 11C flow into hydrophobic structural components and amino acids. When nitrogen stressed, non-inoculated maize exhibited a decrease in carbon dioxide fixation, root allocation of 11C-photosynthates, and decreased 11Cexudation compared to control maize. They also saw increased 11C flow into hydrophobic structural components and sugars. When inoculated with A. brasilense and subjected to nitrogen stress, the same enhancements occurred- but fixation, allocation, and exudation recovered to near control maize levels, suggesting these bacteria ameliorate some abiotic stresses. Finally, 59Fe and [11C]CO2 radiotracers were applied to the functional mutants of A. brasilense to uncover how various biological functions were impacted by light exposure. First, light transmittance from shoot to root tissues, called light piping, in maize was shown using a DSLR camera and image intensifier. Studies showed the functional mutants with biological nitrogen fixation (BNF) capacity had enhanced assimilation of 59Fe when exposed to light relative to dark treatments and greater activity of the nitrogenase enzyme as measured by acetylene reduction assay in light, with a greater response noted for red than blue light wavelengths. Carbon assimilation as [11C]CO2 and subsequent metabolism in these bacteria were also impacted by light stimulus.

scholarly journals The SARS-CoV-2 Nucleocapsid Protein and Its Role in Viral Structure, Biological Functions, and a Potential Target for Drug or Vaccine Mitigation

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1115
Author(s):  
Zhihua Bai ◽  
Ying Cao ◽  
Wenjun Liu ◽  
Jing Li
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Nucleocapsid Protein ◽  
Drug Target ◽  
Vaccine Candidate ◽  
Structural Components ◽  
Biological Functions ◽  
N Protein ◽  
Viral Structure ◽  
Novel Virus ◽  
The Impact

The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on the world is still expanding. Thus, there is an urgent need to better understand this novel virus and find a way to control its spread. Like other coronaviruses, the nucleocapsid (N) protein is one of the most crucial structural components of SARS-CoV-2. This protein shares 90% homology with the severe acute respiratory syndrome coronavirus N protein, implying functional significance. Based on the evolutionary conservation of the N protein in coronavirus, we reviewed the currently available knowledge regarding the SARS-CoV-2 N protein in terms of structure, biological functions, and clinical application as a drug target or vaccine candidate.

Climate-forced changes of bio-productivity of Belorussian terrestrial ecosystems

2019 ◽  
pp. 77-88
Author(s):  
S. A. Lysenko
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Vegetation Index ◽  
Precipitation Amount ◽  
Terrestrial Ecosystems ◽  
Vegetation Period ◽  
Climatic Trend ◽  
Vegetation Growth ◽  
Current Century ◽  
The Impact

The spatial and temporal particularities of Normalized Differential Vegetation Index (NDVI) changes over territory of Belarus in the current century and their relationship with climate change were investigated. The rise of NDVI is observed at approximately 84% of the Belarus area. The statistically significant growth of NDVI has exhibited at nearly 35% of the studied area (t-test at 95% confidence interval), which are mainly forests and undeveloped areas. Croplands vegetation index is largely descending. The main factor of croplands bio-productivity interannual variability is precipitation amount in vegetation period. This factor determines more than 60% of the croplands NDVI dispersion. The long-term changes of NDVI could be explained by combination of two factors: photosynthesis intensifying action of carbon dioxide and vegetation growth suppressing action of air warming with almost unchanged precipitation amount. If the observed climatic trend continues the croplands bio-productivity in many Belarus regions could be decreased at more than 20% in comparison with 2000 year. The impact of climate change on the bio-productivity of undeveloped lands is only slightly noticed on the background of its growth in conditions of rising level of carbon dioxide in the atmosphere.

scholarly journals Windblown Sand-Induced Degradation of Glass Panels in Curtain Walls

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 607
Author(s):  
Yuxi Zhao ◽  
Rongcheng Liu ◽  
Fan Yan ◽  
Dawei Zhang ◽  
Junjin Liu
Keyword(s):  
Visible Light ◽  
Mass Loss ◽  
Effective Area ◽  
Area Ratio ◽  
Light Transmittance ◽  
Relative Mass ◽  
Impact Time ◽  
Windblown Sand ◽  
Glass Panels ◽  
The Impact

The windblown sand-induced degradation of glass panels influences the serviceability and safety of these panels. In this study, the degradation of glass panels subject to windblown sand with different impact velocities and impact angles was studied based on a sandblasting test simulating a sandstorm. After the glass panels were degraded by windblown sand, the surface morphology of the damaged glass panels was observed using scanning electron microscopy, and three damage modes were found: a cutting mode, smash mode, and plastic deformation mode. The mass loss, visible light transmittance, and effective area ratio values of the glass samples were then measured to evaluate the effects of the windblown sand on the panels. The results indicate that, at high abrasive feed rates, the relative mass loss of the glass samples decreases initially and then remains steady with increases in impact time, whereas it increases first and then decreases with an increase in impact angle such as that for ductile materials. Both visible light transmittance and effective area ratio decrease with increases in the impact time and velocities. There exists a positive linear relationship between the visible light transmittance and effective area ratio.

scholarly journals A Fundamental Study on the Development of New Energy Performance Index in Office Buildings

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2064
Author(s):  
Jin-Hee Kim ◽  
Seong-Koo Son ◽  
Gyeong-Seok Choi ◽  
Young-Tag Kim ◽  
Sung-Bum Kim ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Energy Requirement ◽  
Energy Performance ◽  
Office Buildings ◽  
Light Transmittance ◽  
Wall Structure ◽  
Fundamental Study ◽  
Future Studies ◽  
U Value ◽  
The Impact

Recently, there have been significant concerns regarding excessive energy use in office buildings with a large window-to-wall ratio (WWR) because of the curtain wall structure. However, prior research has confirmed that the impact of the window area on energy consumption varies depending on building size. A newly proposed window-to-floor ratio (WFR) correlates better with energy consumption in the building. In this paper, we derived the correlation by analyzing a simulation using EnergyPlus, and the results are as follows. In the case of small buildings, the results of this study showed that the WWR and energy requirement increase proportionally, and the smaller the size is, the higher the energy sensitivity will be. However, results also confirmed that this correlation was not established for buildings approximately 3600 m2 or larger. Nevertheless, from analyzing the correlation between the WFR and the energy requirements, it could be deduced that energy required increased proportionally when the WFR was 0.1 or higher. On the other hand, the correlation between WWR, U-value, solar heat gain coefficient (SHGC), and material property values of windows had little effect on energy when the WWR was 20%, and the highest effect was seen at a WWR of 100%. Further, with an SHGC below 0.3, the energy requirement decreased with an increasing WWR, regardless of U-value. In addition, we confirmed the need for in-depth research on the impact of the windows’ U-value, SHGC, and WWR, and this will be verified through future studies. In future studies on window performance, U-value, SHGC, visible light transmittance (VLT), wall U-value as sensitivity variables, and correlation between WFR and building size will be examined.

scholarly journals An Examination of Green Credit Promoting Carbon Dioxide Emissions Reduction: A Provincial Panel Analysis of China

2021 ◽  
Vol 13 (13) ◽  
pp. 7148
Author(s):  
Wenjie Zhang ◽  
Mingyong Hong ◽  
Juan Li ◽  
Fuhong Li
Keyword(s):  
Carbon Dioxide ◽  
Carbon Emissions ◽  
Carbon Dioxide Emissions ◽  
Industrial Structure ◽  
Emissions Reduction ◽  
Green Finance ◽  
Carbon Emissions Reduction ◽  
Negative Effect ◽  
Emissions Intensity ◽  
The Impact

The implementation of green finance is a powerful measure to promote global carbon emissions reduction that has been highly valued by academic circles in recent years. However, the role of green credit in carbon emissions reduction in China is still lacking testing. Using a set of panel data including 30 provinces and cities, this study focused on the impact of green credit on carbon dioxide emissions in China from 2006 to 2016. The empirical results indicated that green credit has a significantly negative effect on carbon dioxide emissions intensity. Furthermore, after the mechanism examination, we found that the promotion impacts of green credit on industrial structure upgrading and technological innovation are two effective channels to help reduce carbon dioxide emissions. Heterogeneity analysis found that there are regional differences in the effect of green credit. In the western and northeastern regions, the effect of green credit is invalid. Quantile regression results implied that the greater the carbon emissions intensity, the better the effect of green credit. Finally, a further discussion revealed there exists a nonlinear correlation between green credit and carbon dioxide emissions intensity. These findings suggest that the core measures to promote carbon emission reduction in China are to continue to expand the scale of green credit, increase the technology R&D investment of enterprises, and to vigorously develop the tertiary industry.

scholarly journals Twenty Years of Research in Seabass and Seabream Welfare during Slaughter

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2164
Author(s):  
Ignacio de la Rosa ◽  
Pedro L. Castro ◽  
Rafael Ginés
Keyword(s):  
Carbon Dioxide ◽  
Adverse Reaction ◽  
Loss Of Consciousness ◽  
Stressful Situation ◽  
Clove Oil ◽  
Fish Welfare ◽  
Behavioural Responses ◽  
Welfare Indicators ◽  
New Methods ◽  
The Impact

The behavioural responses of fish to a stressful situation must be considered an adverse reaction caused by the perception of pain. Consequently, the handling prior to stunning and the immediacy of loss consciousness following stunning are the aspects to take into account during the slaughtering process. The most common commercial stunning method in seabream and seabass is based on hypothermia, but other methods such as electrical stunning, carbon dioxide narcosis or anaesthetic with clove oil, are discussed in relation to the time to reach the unconsciousness stage and some welfare indicators. Although seawater plus ice slurry is currently accepted in some guidelines of fish welfare well practices at slaughter, it cannot be considered completely adequate due to the deferred speed at which cause loss of consciousness. New methods of incorporating some kind of anaesthetic in the stunning tank could be a solution to minimize the impact on the welfare of seabass and seabream at slaughtering.

scholarly journals Estimating Causal Effects When the Treatment Affects All Subjects Simultaneously: An Application

2021 ◽  
Vol 5 (2) ◽  
pp. 22
Author(s):  
Chiara Binelli
Keyword(s):  
Machine Learning ◽  
Carbon Dioxide ◽  
Global Warming ◽  
Carbon Dioxide Emissions ◽  
Control Group ◽  
Sources Of Information ◽  
Average Global Temperature ◽  
Causal Impact ◽  
The Impact ◽  
Robust Evidence

Several important questions cannot be answered with the standard toolkit of causal inference since all subjects are treated for a given period and thus there is no control group. One example of this type of questions is the impact of carbon dioxide emissions on global warming. In this paper, we address this question using a machine learning method, which allows estimating causal impacts in settings when a randomized experiment is not feasible. We discuss the conditions under which this method can identify a causal impact, and we find that carbon dioxide emissions are responsible for an increase in average global temperature of about 0.3 degrees Celsius between 1961 and 2011. We offer two main contributions. First, we provide one additional application of Machine Learning to answer causal questions of policy relevance. Second, by applying a methodology that relies on few directly testable assumptions and is easy to replicate, we provide robust evidence of the man-made nature of global warming, which could reduce incentives to turn to biased sources of information that fuels climate change skepticism.

scholarly journals Decarbonization of Residential Building Energy Supply: Impact of Cogeneration System Performance on Energy, Environment, and Economics

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2538
Author(s):  
Praveen K. Cheekatamarla
Keyword(s):  
Carbon Dioxide ◽  
Power Generation ◽  
Energy Consumption ◽  
Carbon Footprint ◽  
Residential Buildings ◽  
Building Energy ◽  
Primary Energy ◽  
Primary Energy Consumption ◽  
Cogeneration System ◽  
The Impact

Electrical and thermal loads of residential buildings present a unique opportunity for onsite power generation, and concomitant thermal energy generation, storage, and utilization, to decrease primary energy consumption and carbon dioxide intensity. This approach also improves resiliency and ability to address peak load burden effectively. Demand response programs and grid-interactive buildings are also essential to meet the energy needs of the 21st century while addressing climate impact. Given the significance of the scale of building energy consumption, this study investigates how cogeneration systems influence the primary energy consumption and carbon footprint in residential buildings. The impact of onsite power generation capacity, its electrical and thermal efficiency, and its cost, on total primary energy consumption, equivalent carbon dioxide emissions, operating expenditure, and, most importantly, thermal and electrical energy balance, is presented. The conditions at which a cogeneration approach loses its advantage as an energy efficient residential resource are identified as a function of electrical grid’s carbon footprint and primary energy efficiency. Compared to a heat pump heating system with a coefficient of performance (COP) of three, a 0.5 kW cogeneration system with 40% electrical efficiency is shown to lose its environmental benefit if the electrical grid’s carbon dioxide intensity falls below 0.4 kg CO2 per kWh electricity.

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