Mitochondrial metabolism during daily torpor in the dwarf Siberian hamster: role of active regulated changes and passive thermal effects

2007 ◽  
Vol 293 (5) ◽  
pp. R1833-R1845 ◽  
Author(s):  
Jason C. L. Brown ◽  
Alexander R. Gerson ◽  
James F. Staples
Keyword(s):  
Metabolic Rate ◽  
Mitochondrial Respiration ◽  
Thermal Effects ◽  
Substrate Oxidation ◽  
Daily Torpor ◽  
Inner Mitochondrial Membrane ◽  
Temperature Dependent ◽  
Oxidation Capacity ◽  
Siberian Hamster

During daily torpor in the dwarf Siberian hamster, Phodopus sungorus, metabolic rate is reduced by 65% compared with the basal rate, but the mechanisms involved are contentious. We examined liver mitochondrial respiration to determine the possible role of active regulated changes and passive thermal effects in the reduction of metabolic rate. When assayed at 37°C, state 3 (phosphorylating) respiration, but not state 4 (nonphosphorylating) respiration, was significantly lower during torpor compared with normothermia, suggesting that active regulated changes occur during daily torpor. Using top-down elasticity analysis, we determined that these active changes in torpor included a reduced substrate oxidation capacity and an increased proton conductance of the inner mitochondrial membrane. At 15°C, mitochondrial respiration was at least 75% lower than at 37°C, but there was no difference between normothermia and torpor. This implies that the active regulated changes are likely more important for reducing respiration at high temperatures (i.e., during entrance) and/or have effects other than reducing respiration at low temperatures. The decrease in respiration from 37°C to 15°C resulted predominantly from a considerable reduction of substrate oxidation capacity in both torpid and normothermic animals. Temperature-dependent changes in proton leak and phosphorylation kinetics depended on metabolic state; proton leakiness increased in torpid animals but decreased in normothermic animals, whereas phosphorylation activity decreased in torpid animals but increased in normothermic animals. Overall, we have shown that both active and passive changes to oxidative phosphorylation occur during daily torpor in this species, contributing to reduced metabolic rate.

Use of Second Harmonic and Thermal Effects of Laser Voltage Probing for Better Fault Isolation

2016 ◽  
Author(s):  
Ramya Yeluri ◽  
Ravishankar Thirugnanasambandam ◽  
Cameron Wagner ◽  
Jonathan Urtecho ◽  
Jan M. Neirynck
Keyword(s):  
Duty Cycle ◽  
Thermal Effects ◽  
Second Harmonic ◽  
Fault Isolation ◽  
Advanced Technology ◽  
Temperature Dependent ◽  
First Case ◽  
Improve Accuracy ◽  
Degradation Monitoring ◽  
Technology Nodes

Abstract Laser voltage probing (LVP) has been extensively used for fault isolation over the last decade; however fault isolation in practice primarily relies on good-to-bad comparisons. In the case of complex logic failures at advanced technology nodes, understanding the components of the measured data can improve accuracy and speed of fault isolation. This work demonstrates the use of second harmonic and thermal effects of LVP to improve fault isolation with specific examples. In the first case, second harmonic frequency is used to identify duty cycle degradation. Monitoring the relative amplitude of the second harmonic helps identify minute deviations in the duty cycle with a scan over a region, as opposed to collecting multiple high resolution waveforms at each node. This can be used to identify timing degradation such as signal slope variation as well. In the second example, identifying abnormal data at the failing device as temperature dependent effect helps refine the fault isolation further.

Role of Panchakarma in the management of Hypothyroidism

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Dr.Suraj Kumbar ◽  
Dr.Lohith BA ◽  
Dr.Ashvinikumar M ◽  
Dr. Amritha R ◽  
Dr. Shameem Banu
Keyword(s):  
Metabolic Rate ◽  
Pituitary Gland ◽  
Life Style ◽  
The Body ◽  
Management Guidelines ◽  
Quality Of Food ◽  
Sedentary Life ◽  
Sedentary Life Style

We are in technical era where there is more of sedentary life style and stress along with this urbanization is affecting our quality of food and health. This is leading to many lifestyle disorders and hormonal imbalances in our body. Hypothyroidism one among the endocrinal disorder. Thyroid is an endocrinal gland secrets T3 and T4 hormones regulated by TSH which is secreted by Pituitary gland. These hormones have two major effects on the body, 1) To increase the overall metabolic rate in the body 2) To stimulate growth in children. Hypothyroidism is common health issue in India. The highest prevalence of hypothyroidism (13.1%) is noted in people aged 46-54yrs old. With people aged 18-35 yrs being less affected (7.5%). To prevent these hazards Panchakarma is beneficiary to maintain metabolic rate. Here an attempt is made to diagnose hypothyroidism in the light of Ayurveda and management guidelines through Panchakarma.

scholarly journals Oxidation of Terpenoids to Achieve High-Value Flavor and Fragrances—Questioning Microalgae Oxidative Capabilities in the Biotransformation of the Sesquiterpene Valencene and of Selected Natural Apocarotenoids

Chemistry ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 821-830
Author(s):  
Davide De Simeis ◽  
Stefano Serra ◽  
Alessandro Di Fonzo ◽  
Francesco Secundo
Keyword(s):  
Experimental Data ◽  
Natural Products ◽  
Aqueous Medium ◽  
Photochemical Reaction ◽  
Substrate Oxidation ◽  
Market Size ◽  
Chlorella Sp ◽  
General Opinion ◽  
Natural Way

Natural flavor and fragrance market size is expected to grow steadily due to the rising consumer demand of natural ingredients. This market request is guided by the general opinion that the production of natural compounds leads to a reduction of pollution, with inherent advantages for the environment and people’s health. The biotransformation reactions have gained high relevance in the production of natural products. In this context, few pieces of research have described the role of microalgae in the oxidation of terpenoids. In this present study, we questioned the role of microalgal based oxidation in the synthesis of high-value flavors and fragrances. This study investigated the role of three different microalgae strains, Chlorella sp. (211.8b and 211.8p) and Chlorococcum sp. (JB3), in the oxidation of different terpenoid substrates: α-ionone, β-ionone, theaspirane and valencene. Unfortunately, the experimental data showed that the microalgal strains used are not responsible for the substrate oxidation. In fact, our experiments demonstrate that the transformation of the four starting compounds is a photochemical reaction that involves the oxygen as oxidant. Even though these findings cast a shadow on the use of these microorganisms for an industrial purpose, they open a new possible strategy to easily obtain nootkatone in a natural way by just using an aqueous medium, oxygen and light.

scholarly journals Exploration of Free Energy Surface and Thermal Effects on Relative Population and Infrared Spectrum of the Be6B11− Fluxional Cluster

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 112
Author(s):  
Carlos Emiliano Buelna-Garcia ◽  
José Luis Cabellos ◽  
Jesus Manuel Quiroz-Castillo ◽  
Gerardo Martinez-Guajardo ◽  
Cesar Castillo-Quevedo ◽  
...  
Keyword(s):  
Free Energy ◽  
Infrared Spectrum ◽  
Infrared Spectra ◽  
Thermal Effects ◽  
Global Minimum ◽  
Energy Surface ◽  
Weighted Sums ◽  
Free Energy Surface ◽  
Temperature Dependent ◽  
Relative Population

The starting point to understanding cluster properties is the putative global minimum and all the nearby local energy minima; however, locating them is computationally expensive and difficult. The relative populations and spectroscopic properties that are a function of temperature can be approximately computed by employing statistical thermodynamics. Here, we investigate entropy-driven isomers distribution on Be6B11− clusters and the effect of temperature on their infrared spectroscopy and relative populations. We identify the vibration modes possessed by the cluster that significantly contribute to the zero-point energy. A couple of steps are considered for computing the temperature-dependent relative population: First, using a genetic algorithm coupled to density functional theory, we performed an extensive and systematic exploration of the potential/free energy surface of Be6B11− clusters to locate the putative global minimum and elucidate the low-energy structures. Second, the relative populations’ temperature effects are determined by considering the thermodynamic properties and Boltzmann factors. The temperature-dependent relative populations show that the entropies and temperature are essential for determining the global minimum. We compute the temperature-dependent total infrared spectra employing the Boltzmann factor weighted sums of each isomer’s infrared spectrum and find that at finite temperature, the total infrared spectrum is composed of an admixture of infrared spectra that corresponds to the spectra of the lowest-energy structure and its isomers located at higher energies. The methodology and results describe the thermal effects in the relative population and the infrared spectra.

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