scholarly journals Energy supply per neuron is constrained by capillary density in the mouse brain

2020 ◽  
Author(s):  
Lissa Ventura-Antunes ◽  
Suzana Herculano-Houzel
Keyword(s):  
Mouse Brain ◽  
Energy Supply ◽  
Energy Demand ◽  
Energy Requirement ◽  
Capillary Density ◽  
High Energy ◽  
Neuronal Density ◽  
Capillary Bed ◽  
Neuronal Size ◽  
The Brain

AbstractNeuronal densities vary enormously across sites within a brain. Does the density of the capillary bed accompany the presumably larger energy requirement of sites with more neurons, or with larger neurons, or is energy supply constrained by a mostly homogeneous capillary bed? Here we find evidence for the latter across various sites in the mouse brain and show that as a result, the ratio of capillary cells per neuron, and thus presumably blood and energy supply per neuron, decreases uniformly with increasing neuronal density and therefore smaller average neuronal size across sites. Additionally, we find that local capillary density is also not correlated with local synapse densities, although there is a small but significant correlation between lower neuronal density (and therefore larger neuronal size) and more synapses per neuron within the restricted range of 6,500-9,500 across cortical sites. Further, local variations in the glial/neuron ratio are also not correlated with local variations in number of synapses per neuron or local synaptic densities. These findings suggest that it is not that larger neurons, neurons with more synapses, or even sites with more synapses demand more energy, but simply that larger (and thus fewer) neurons have more energy available per cell, and to its synapses as a whole, than smaller (and thus more numerous) neurons due to competition for limited resources supplied by a capillary bed of fairly homogeneous density throughout the brain.Significance StatementThe brain is an expensive organ and at rest already uses nearly as much energy as during sensory activation. To ultimately determine whether the high energy cost of the brain is driven by an unusually high energy demand by neurons or constrained by capillary density in the organ, we examine whether sites in the mouse brain with more neurons, larger neurons, or more synapses have more capillary supply, and find instead that capillary density is mostly homogeneous across brain structures. We propose that neurons are constrained to using what energy is available, with little evidence for adjustments according to local demand, which explains its high risk of ischemia and vulnerability to states of compromised metabolism, including normal aging.

scholarly journals Reduction of air pollution as a basis for a healthy urban environment

2019 ◽  
Vol 97 ◽  
pp. 01042
Author(s):  
Anna Lis
Keyword(s):  
Air Pollution ◽  
Energy Demand ◽  
Thermal Protection ◽  
Residential Buildings ◽  
Energy Requirement ◽  
Renewable Energy Sources ◽  
High Energy ◽  
Premature Deaths ◽  
The World ◽  
Environmental Causes

The WHO report shows that air in the majority of cities in the world is polluted to a large extent. Air pollution is one of the basic environmental causes of premature deaths in the world. The main source of air pollution in cities is the low emission associated with fuel combustion to generate heat for buildings heating, communication and industry. The existing buildings in Poland are characterized by high energy and, consequently, ecological potential. The aim is to estimate predicted energetic and ecological effects of activities that adapt existing residential buildings to the requirements for the thermal protection of buildings in Poland and presenting the possibility of using renewable energy sources. The energy demand for heating buildings at 60-70 kWh/(m2rok) has been adopted. The calculations show that as a result of this adjustment, the energy demand for heating in residential buildings may decrease by an average of around 67% compared to 2011. Such actions will reduce the overall emissions of air pollution from households by reducing the energy requirement for heating apartments from about 30% to about 67%, depending on the type of pollutant.

scholarly journals An Analysis of Activity, Intensity and Structural Effect on Change in Energy Consumption in Bangladesh using Complete Decomposition Model (CDM)

2012 ◽  
Vol 47 (1) ◽  
pp. 61-68
Author(s):  
S Khosruzzaman ◽  
MA Asgar ◽  
MA Asgar ◽  
KMR Rahman ◽  
S Akbar
Keyword(s):  
Energy Consumption ◽  
Energy Supply ◽  
Energy Demand ◽  
High Energy ◽  
Structural Effect ◽  
Energy Problem ◽  
Economic Sectors ◽  
Decomposition Model ◽  
Activity Intensity ◽  
Intensive Group

For the purpose of identifying the vulnerable aspects of our energy problem and to seek an appropriate solution, the total energy supply, energy demand and energy consumption need to be analyzed in respect of their components. We have used the decomposition model for analyzing the correlation between energy consumption and economic development up to 2007 taking 1990 as the base year. The relative impacts of activity, intensity and structure effect are analyzed for different economic sectors in Bangladesh. Moreover, the country's economy is disaggregated in to two groups' namely low energy intensive group and high-energy intensive group. The trends of energy uses in the above groups are also evaluated to provide a basis for assessment of sustainability. DOI: http://dx.doi.org/10.3329/bjsir.v47i1.10726 Bangladesh J. Sci. Ind. Res. 47(1), 61-68, 2012

scholarly journals When It Comes to an End: Oxidative Stress Crosstalk with Protein Aggregation and Neuroinflammation Induce Neurodegeneration

Antioxidants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 740 ◽  
Author(s):  
Patrycja Michalska ◽  
Rafael León
Keyword(s):  
Oxidative Stress ◽  
Neurodegenerative Diseases ◽  
Energy Demand ◽  
Molecular Mechanisms ◽  
Neuronal Damage ◽  
High Energy ◽  
Antioxidant Defenses ◽  
Loss Of Function ◽  
Age Related ◽  
The Brain

Neurodegenerative diseases are characterized by a progressive loss of neurons in the brain or spinal cord that leads to a loss of function of the affected areas. The lack of effective treatments and the ever-increasing life expectancy is raising the number of individuals affected, having a tremendous social and economic impact. The brain is particularly vulnerable to oxidative damage given the high energy demand, low levels of antioxidant defenses, and high levels of metal ions. Driven by age-related changes, neurodegeneration is characterized by increased oxidative stress leading to irreversible neuronal damage, followed by cell death. Nevertheless, neurodegenerative diseases are known as complex pathologies where several mechanisms drive neuronal death. Herein we discuss the interplay among oxidative stress, proteinopathy, and neuroinflammation at the early stages of neurodegenerative diseases. Finally, we discuss the use of the Nrf2-ARE pathway as a potential therapeutic strategy based on these molecular mechanisms to develop transformative medicines.

scholarly journals Distinct mitochondrial remodeling during early cardiomyocyte development in a human-based stem cell model

2021 ◽  
Author(s):  
Sepideh Mostafavi ◽  
Novin Balafkan ◽  
Ina Katrine Nitschke Pettersen ◽  
Gonzalo S. Nido ◽  
Richard Siller ◽  
...  
Keyword(s):  
Energy Demand ◽  
Cell Model ◽  
Energy Requirement ◽  
Mitochondrial Respiratory Chain ◽  
High Energy ◽  
Mitochondrial Activity ◽  
Cardiomyocyte Differentiation ◽  
Mitochondrial Content ◽  
Activity Increase ◽  
Cardiac Progenitors

Post-mitotic tissues with high-energy demand rely on ATP generated by the mitochondrial respiratory chain through the process of oxidative phosphorylation (OXPHOS). There is common agreement that mitochondrial content and OXPHOS activity increase as cells exit from pluripotency state to meet the higher energy requirement of differentiated tissues such as heart. In this study, we examined the hypothesis that mitochondrial expansion during differentiation is necessary to compensate for higher energy demand in differentiated cells. We assessed mitochondrial and cellular metabolism during differentiation of human pluripotent stem cells to cardiac progenitors and further to functional cardiomyocytes. Contrary to expectations, we found that mitochondrial content decreased progressively during mesoderm differentiation. Nevertheless, we found that there was increased mitochondrial activity and higher levels of ATP-linked respiration, which we suggest more than compensate for the lower mitochondrial number. Our findings support a model whereby mitochondrial maturation during cardiomyocyte differentiation depends on increased efficiency of ATP generation through OXPHOS not increased mitochondrial biogenesis. Thus, the timing of the mitochondria expansion during cardiomyocyte differentiation will have to be revisited in light of these findings.

Dependence of muscle fatigue on stimulation protocol: effect of hypocaloric diet

1992 ◽  
Vol 72 (6) ◽  
pp. 2278-2284 ◽  
Author(s):  
C. J. Barclay ◽  
D. S. Loiselle
Keyword(s):  
Fatigue Test ◽  
Fatigue Resistance ◽  
Energy Supply ◽  
Energy Demand ◽  
Isometric Force ◽  
High Energy ◽  
Control Group ◽  
Stimulation Protocol ◽  
Initial Value ◽  
Inadequate Nutrition

This study tested the hypothesis that the decreased resistance of skeletal muscles to fatigue after a period of inadequate nutrition is a consequence of the type of fatigue test employed. Rats (n = 8) were fed hypocalorically for 10 days, resulting in a 33.5 +/- 3.0% (SE) reduction in body weight. The fatigue resistance of muscles was assessed with use of isolated soleus muscles at a temperature of 25 degrees C. Fatigue resistance was determined from the decline in isometric force during a series of tetanic contractions. Two contrasting contraction protocols were devised to test the susceptibility of muscles to fatigue. One protocol was designed to require high rates of energy supply and hence force a dependence on glycolytic energy supply pathways. The second protocol required much lower rates of energy supply that could be entirely met by oxidative energy supply processes. During the high energy demand (glycolytic) protocol, the force produced by muscles from a control group of rats decreased to 78.7 +/- 0.8% (n = 12 muscles) of the initial value. Hypocaloric feeding significantly reduced the resistance of muscles to fatigue: force declined to 61.3 +/- 3.5% (n = 16 muscles) during the contraction protocol. In contrast, when fatigue was quantified using the low energy demand (oxidative) contraction protocol, the effect of nutritional status on fatigue resistance was entirely abolished. This result supports the hypothesis that resistance to fatigue is critically dependent on the fatigue test employed.

scholarly journals Comparison of Greenhouse Energy Requirements for Rose Cultivation in Europe and North Africa

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 422 ◽  
Author(s):  
Gabriele Cola ◽  
Luigi Mariani ◽  
Stefania Toscano ◽  
Daniela Romano ◽  
Antonio Ferrante
Keyword(s):  
Energy Balance ◽  
Environmental Sustainability ◽  
Energy Demand ◽  
Energy Requirement ◽  
Final Analysis ◽  
High Energy ◽  
Plant Production ◽  
Balance Model ◽  
Time Step ◽  
European Area

The ornamental plant production in greenhouses is widespread. A quantitative assessment of greenhouse energy consumption and its variability in space and time is strategic to improve the sustainability of the cultivation. The specific environmental features of the cultivation areas can strongly affect the sustainability of the production. A dynamic simulation model of greenhouse energy balance with an hourly time step was developed and parameterized for a state-of-the-art greenhouse to evaluate the heating requirements for cut-flower roses. This ornamental crop has been used as model species for its high energy requirement for flower production. The energy demand for rose production has been analyzed with an energy balance model with an hourly time step. After a preliminary analysis on the period 1973–2019, the final analysis was carried out on the 30-year period (1990–2019), representative of the current climate. Results show a gradient southwest–northeast of energy needs with relevant effects on economic and environmental sustainability. More specifically, four large sub-areas are identified, namely the central-southern Mediterranean (yearly requirements below 600 MJ m−2 year), the northern Mediterranean, and the area influenced by the mitigating effect of the Atlantic Ocean (600–1200), the central-European area (requirements of 1200–1800), and the Northern European area (above 1800).

Fuzzy multi-objective decision making approach for nuclear power plant installation

2020 ◽  
Vol 39 (5) ◽  
pp. 6339-6350
Author(s):  
Esra Çakır ◽  
Ziya Ulukan
Keyword(s):  
Linear Programming ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Energy Supply ◽  
Energy Demand ◽  
Nuclear Power ◽  
Power Plants ◽  
Total Duration ◽  
Objective Functions ◽  
Multi Objective

Due to the increase in energy demand, many countries suffer from energy poverty because of insufficient and expensive energy supply. Plans to use alternative power like nuclear power for electricity generation are being revived among developing countries. Decisions for installation of power plants need to be based on careful assessment of future energy supply and demand, economic and financial implications and requirements for technology transfer. Since the problem involves many vague parameters, a fuzzy model should be an appropriate approach for dealing with this problem. This study develops a Fuzzy Multi-Objective Linear Programming (FMOLP) model for solving the nuclear power plant installation problem in fuzzy environment. FMOLP approach is recommended for cases where the objective functions are imprecise and can only be stated within a certain threshold level. The proposed model attempts to minimize total duration time, total cost and maximize the total crash time of the installation project. By using FMOLP, the weighted additive technique can also be applied in order to transform the model into Fuzzy Multiple Weighted-Objective Linear Programming (FMWOLP) to control the objective values such that all decision makers target on each criterion can be met. The optimum solution with the achievement level for both of the models (FMOLP and FMWOLP) are compared with each other. FMWOLP results in better performance as the overall degree of satisfaction depends on the weight given to the objective functions. A numerical example demonstrates the feasibility of applying the proposed models to nuclear power plant installation problem.

Changes in lipid peroxidation during pregnancy and after delivery in rats: effect of pinealectomy

Reproduction ◽  
2000 ◽  
pp. 143-149 ◽  
Author(s):  
RM Sainz ◽  
RJ Reiter ◽  
JC Mayo ◽  
J Cabrera ◽  
DX Tan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Oxidative Damage ◽  
Energy Demand ◽  
Physiological State ◽  
High Energy ◽  
Free Radical Scavengers ◽  
Radical Scavengers ◽  
Oxygen Requirement ◽  
Pregnant Rats

Pregnancy is a physiological state accompanied by a high energy demand of many bodily functions and an increased oxygen requirement. Because of the increased intake and utilization of oxygen, increased levels of oxidative stress would be expected. In the present study, the degree of lipid peroxidation was examined in different tissues from non-pregnant and pregnant rats after the delivery of their young. Melatonin and other indole metabolites are known to be direct free radical scavengers and indirect antioxidants. Thus the effect of pinealectomy at 1 month before pregnancy on the accumulation of lipid damage was investigated in non-pregnant and pregnant rats after the delivery of their young. Malonaldehyde and 4-hydroxyalkenal concentrations were measured in the lung, uterus, liver, brain, kidney, thymus and spleen from intact and pinealectomized pregnant rats soon after birth of their young and at 14 and 21 days after delivery. The same parameters were also evaluated in intact and pinealectomized non-pregnant rats. Shortly after delivery, lipid oxidative damage was increased in lung, uterus, brain, kidney and thymus of the mothers. No differences were detected in liver and spleen. Pinealectomy enhanced this effect in the uterus and lung. It is concluded that during pregnancy high levels of oxidative stress induce an increase in oxidative damage to lipids, which in some cases is inhibited by the antioxidative actions of pineal indoles.

scholarly journals Green synthesis: Proposed mechanism and factors influencing the synthesis of platinum nanoparticles

2020 ◽  
Vol 9 (1) ◽  
pp. 386-398 ◽  
Author(s):  
Mahmood S. Jameel ◽  
Azlan Abdul Aziz ◽  
Mohammed Ali Dheyab
Keyword(s):  
Green Synthesis ◽  
Reaction Temperature ◽  
Platinum Nanoparticles ◽  
Energy Requirement ◽  
Average Particle Size ◽  
High Energy ◽  
Energy Utilization ◽  
Critical Parameters ◽  
Synthesis Process ◽  
Average Particle

AbstractPlatinum nanoparticles (Pt NPs) have attracted interest in catalysis and biomedical applications due to their unique structural, optical, and catalytic properties. However, the conventional synthesis of Pt NPs using the chemical and physical methods is constrained by the use of harmful and costly chemicals, intricate preparation requirement, and high energy utilization. Hence, this review emphasizes on the green synthesis of Pt NPs using plant extracts as an alternative approach due to its simplicity, convenience, inexpensiveness, easy scalability, low energy requirement, environmental friendliness, and minimum usage of hazardous materials and maximized efficiency of the synthesis process. The underlying complex processes that cover the green synthesis (biosynthesis) of Pt NPs were reviewed. This review affirms the effects of different critical parameters (pH, reaction temperature, reaction time, and biomass dosage) on the size and shape of the synthesized Pt NPs. For instance, the average particle size of Pt NPs was reported to decrease with increasing pH, reaction temperature, and concentration of plant extract.

scholarly journals The Quorum Sensing Auto-Inducer 2 (AI-2) Stimulates Nitrogen Fixation and Favors Ethanol Production over Biomass Accumulation in Zymomonas mobilis

2021 ◽  
Vol 22 (11) ◽  
pp. 5628
Author(s):  
Valquíria Campos Alencar ◽  
Juliana de Fátima dos Santos Silva ◽  
Renata Ozelami Vilas Boas ◽  
Vinícius Manganaro Farnézio ◽  
Yara N. L. F. de Maria ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Quorum Sensing ◽  
Ethanol Production ◽  
N2 Fixation ◽  
Energy Demand ◽  
Zymomonas Mobilis ◽  
Biomass Accumulation ◽  
High Energy ◽  
Gram Negative ◽  
Expression Of Genes

Autoinducer 2 (or AI-2) is one of the molecules used by bacteria to trigger the Quorum Sensing (QS) response, which activates expression of genes involved in a series of alternative mechanisms, when cells reach high population densities (including bioluminescence, motility, biofilm formation, stress resistance, and production of public goods, or pathogenicity factors, among others). Contrary to most autoinducers, AI-2 can induce QS responses in both Gram-negative and Gram-positive bacteria, and has been suggested to constitute a trans-specific system of bacterial communication, capable of affecting even bacteria that cannot produce this autoinducer. In this work, we demonstrate that the ethanologenic Gram-negative bacterium Zymomonas mobilis (a non-AI-2 producer) responds to exogenous AI-2 by modulating expression of genes involved in mechanisms typically associated with QS in other bacteria, such as motility, DNA repair, and nitrogen fixation. Interestingly, the metabolism of AI-2-induced Z. mobilis cells seems to favor ethanol production over biomass accumulation, probably as an adaptation to the high-energy demand of N2 fixation. This opens the possibility of employing AI-2 during the industrial production of second-generation ethanol, as a way to boost N2 fixation by these bacteria, which could reduce costs associated with the use of nitrogen-based fertilizers, without compromising ethanol production in industrial plants.

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