Transport Velocity Research Articles

Number of kinesins engaged in axonal cargo transport: A novel biomarker for neurological disorders

Kinesin motor proteins play crucial roles in anterograde transport of cargo vesicles in neurons, moving them along axons from the cell body towards the synaptic region. Not only the transport force and velocity of single motor protein, but also the number of kinesin molecules involved in transporting a specific cargo, is pivotal for synapse formation. This collective transport by multiple kinesins ensures stable and efficient cargo transport in neurons. Abnormal increases or decreases in the number of engaged kinesin molecules per cargo could potentially act as biomarkers for neurodegenerative diseases such as Alzheimer's, Parkinson's, amyotrophic lateral sclerosis (ALS), spastic paraplegia, polydactyly syndrome, and virus transport disorders. We review here a model constructed using physical measurements to quantify the number of kinesin molecules associated with their cargo, which could shed light on the molecular mechanisms of neurodegenerative diseases related to axonal transport.

Environmental Assessment of Soil and Groundwater Pollution by BTEX Leaching in Valencia Region (Spain)

The impact of hydrocarbon spills in the unsaturated zone is a significant environmental concern, particularly in locations where contamination arises from leaks in underground fuel storage tanks (USTs). This paper presents the outcomes achieved through the utilization of VLEACH, a finite-difference numerical model, to assess the concentrations of organic contaminants in the solid, liquid, and gas phases within the vadose zone. Additionally, it evaluates the mass transfer of pollutants to the aquifer as part of an environmental assessment for the placement of a forthcoming service station. The study encompasses an analysis of 18 scenarios under realistic conditions based on actual field data. These scenarios were constructed, taking into account various factors, including the nature of the leak (one-time or permanent), the depth of the phreatic level, and the soil conditions and properties. The results highlight the potential environmental consequences of a permanent leak as compared to those resulting from a specific accident. The findings further emphasize the substantial influence of soil moisture on transport phenomena within the vadose zone. Variations in soil moisture significantly alter hydraulic conductivity, impact magnitudes, transport velocities, and even the predominant transport mechanism. Consequently, precise delineation of soil moisture becomes a crucial parameter in such simulations. Additionally, it has been observed that each component of BTEX (benzene, toluene, ethylbenzene, and xylene) experiences varying transport velocities through the vadose zone. Benzene, having a greater propensity to concentrate in the liquid and gas phases, exhibits the swiftest movement through the vadose zone. The detection of benzene in aquifers can serve as an indicator of the potential future arrival of the remaining BTEX compounds.

Capture and transport of rod-shaped cargo via programmable active particles

We study the influence of the cargo shape on the capture and transport process of colloidal rods via swarms of active particles using Brownian dynamics simulations. Starting at random initial conditions, active particles that interact via the Lennard-Jones potential and possess a tuneable speed are utilised to capture passive rods inside a hexagonal cage of individually addressable units. By adjusting the velocity of the individual active particles, the rod can then be transported. To guarantee a successful capture process (with a strong localisation), we find that specific geometric and energetic constraints have to be met; i.e., the length of the rod must approximately be in the vicinity of an odd multiple of the lattice constant of the hexagonal cage, and the Lennard-Jones interaction strength must be in the range of 3.0 , k_B T to 6.0 , k_B T. If the cargo aspect ratio gets too large, the subsequent transport of successfully captured rods can fail. For systems where transport is possible, an increase in the cargo aspect ratio decreases the achievable transport velocity. Our work shows that the particle shape must be considered while designing interaction rules to accomplish specific tasks via groups of controllable units.

Toward the optimization of fuel consumption on container-on-barge operations in river transportation

The national policy for fuel prices in Colombia and the management of the fluvial route of the Magdalena River has led to effects on productivity and benefits for companies and maritime ports due to contracts for dredging that guarantee drafts for six months. Moreover, increases in fuel prices have generated higher operating costs than those of previous years. Data analysis is a crucial decision-making tool for operational-level decision-makers in companies, supported by the measures of indicators, competitiveness, and productivity in terminal services. The transportation and shipping of cargo entail significant costs in terms of fuel, labor, and time, as well as other costs that must be met for meeting customer commitments.This paper presents a methodology for fuel consumption optimization in the specific case of transportation by a Colombian river transportation company, using regression models and response-surface methodology as optimization tools. This approach yields significant results, reducing fuel consumption by approximately 25% through a combination of various factors involved in barge transportation operations, including labor, fuel, velocity, weight, and other operational aspects. The primary contribution of this research lies in its promotion of sustainable operations through cost reduction and the reduction of fuel consumption reduction. The use of statistical optimization techniques makes this methodology applicable to similar cases of shipping and transportation. It additionally addresses national policy changes related to emissions, fuel costs, and sustainability, thereby aligning with a focus on energy transition to promote cost reduction.

Microplastic and natural sediment in bed load saltation: Material does not dictate the fate.

Microplastic (MP) pollution is a well document threat to our aquatic and terrestrial ecosystems, however, the mechanisms by which MPs are transported in river flows are still unknown. The transport of MPs and natural sediment in aquatic flows could be somewhat comparable, as particles are similar in size. However, it is unknown how the lower density of MPs, their shape and their different material properties impact transport dynamics. To answer this, novel laboratory experiments on bed load saltation dynamics in an open-channel flow, using high-speed camera imaging and the detection of 11,035 individual saltation events were used to identify the similarities and differences between spherical MPs and spherical natural sediments transport. The tested MPs and sediment varied in terms of size and material properties (density and elasticity). Our analysis shows that the Rouse number accurately describes saltation length, height, transport velocity and collision angles equally well for both MPs and natural sediments. Through statistical inference, the distribution functions of saltation trajectory characteristics for MPs were analogous to natural sediment with only one sediment experiment (1.4% of cases) differing from all other plastic experiments. Similarly, only nine experiments (9.3% of cases) showed that collision angles for MPs differed from those of natural sediment experiments. Differences observed in terms of restitution become negligible in overall transport dynamics as turbulence overcomes the kinetic energy lost at particle-bed impact, which keeps particle motion independent from impact. Overall, spherical MP particles behave similarly to spherical natural sediments in aquatic environments under the examined experimental conditions. This is significant because there is an established body of knowledge for sediment transport that can serve as a foundation for the study of MP transport.

Gated nanoparticle transport in a functional group modified nanopore

Inspired by nature, functionalized nanopores have become an important platform in the field of sensing. In this article, we constructed a mathematical model for the gate-controlled manipulation of nanoparticle motion inside pH-responsive polyelectrolyte-modified nanopores and theoretically studied the synergistic control of gate electrode and polyelectrolyte brush layer on nanoparticle motion. By efficiently modifying the charge density and polarity of the polyelectrolyte brush layer located within the nanopore, the gate electrode is capable of actively regulating the velocity of nanoparticle transport through the nanopore. At a solution pH of 5, the higher the gate potential, the faster the nanoparticle transport through the nanopore, which is significantly different from the solution pH of 6. When the gate potential is negative, the degree of ion current blockage increases with increasing gate potential. These results establish a theoretical foundation for the development of novel functionalized nanopores that can be utilized in the field of nanopore sensing.

Dual solutions of Williamson-Casson fluid over a heated exponentially shrinking surface with stability analysis: A novel Catteneo-Christov heat flux model combination

Background In this study, the effects of mixed convective, thermally radiating, magnetized flow of a Williamson-Casson fluid (WCF) over an exponentially shrinking surface in a porous material are investigated. The influences of heat generation-absorption, Joule heating, and a unique Cattaneo-Christov (CC) heat flux model are examined, deviating from traditional research approaches. Methods To analyze the fluid flow, nonlinear partial differential equations (PDEs) governing the system are transformed into ordinary differential equations (ODEs) through similarity transformations and nondimensional variables. The resulting ODEs are solved using the BVP4C technique, yielding dual solutions for a range of the parameter Stability analysis is performed to assess the robustness and reliability of the solutions. Findings Comparisons between the first and second solutions reveal reasonable agreement at specific values of for surface drag force and Nusselt number, validating the existence of dual solutions. The study further investigates the velocity profiles in the Casson model as the Grashof number Gr varies. Fluid velocity decreases, while heat and mass transport velocities increase with higher Gr values. The impact of Gr on all three velocity profiles of Williamson fluid is explored, showing a decrease in fluid velocity and an increase in temperature transport as Gr increases.

Numerical Simulation on Insoluble Surfactant Mass Transfer on Deformable Bubble Interface in a Couette Flow by Phase-Field Lattice Boltzmann Method-Finite-Difference Method Hybrid Approach.

Elaborate management on bubble shape and transportations depends on the balance between multiple physical behaviors for two-phase flow with Marangoni stress and the interface mass transfer. In this paper, a new model combining PFLBM (phase-field lattice Boltzmann method) and FDM ( finite-difference method) coupling with the ghost-cell method was built. The PFLBM-FDM was validated for the high accuracy, less computational cost, and low mass loss compared to other methods. Based on the PFLBM-FDM, a surfactant-laden bubble deformed and transported in a laminar Couette flow was investigated. The deformation ratio and transportation velocity were explored with different density ratios, surface tensions, shear velocities, and diffusion coefficients. The numerical results showed that the equilibrium state of the bubble deformation was decided only by the dimensionless numbers when the Sh number was higher than 100. Moreover, the transportation velocity of the bubble can be controlled by the balance between the Marangoni stress and shear velocity. When the Sh is lower than 100, the Marangoni stress from the surfactant is not a long-range force, which only works at the early flow. Otherwise, the Marangoni stress will be a long-range force that provides a persistent force to accelerate the bubble by ∼10%. Increasing ReH will further intensify the effect. Based on all the data, a correlation of the bubble deformation including with the densities of two fluids was obtained and the error range is less 5%.

Diapirs of crystal-rich slurry explain granite emplacement temperature and duration

The mechanism, temperature, and timescale of granite intrusion remain controversial, with wide-ranging implications for understanding continental growth, differentiation, rheology, and deformation dynamics. In this paper we present a method for determining intrusion emplacement temperature and timescale using the characteristics of the surrounding metamorphic aureole, and apply it to the Skiddaw granite in northern England. The estimated emplacement timescale (0.1–2 Myr) implies magma transport velocities of 1–100 mm/year. At the absent or low melt fractions relevant to our estimated emplacement temperature (580–650 ^{circ }C), such velocities are incompatible with pluton formation by successive injections through dykes. Instead, our results indicate the intrusion of a diapir of crystal-rich slurry, solidifying before emplacement, with a rheology governed by the solid crystals. The emplacement depth is likely to be governed by the depth-dependent rheology of the surrounding rocks, occurring close to the brittle-ductile transition. The wider implications of our results relate to (1) the appreciation that much of the chemical and textural characteristics of plutons may relate to pre-emplacement crystallisation at depth, passively transported to higher crustal levels, and (2) an explanation of the difficulty of seismically imaging active plutonism.

Three-dimensional operando optical imaging of particle and electrolyte heterogeneities inside Li-ion batteries.

Understanding (de)lithiation heterogeneities in battery materials is key to ensure optimal electrochemical performance. However, this remains challenging due to the three-dimensional morphology of electrode particles, the involvement of both solid- and liquid-phase reactants and a range of relevant timescales (seconds to hours). Here we overcome this problem and demonstrate the use of confocal microscopy for the simultaneous three-dimensional operando measurement of lithium-ion dynamics in individual agglomerate particles, and the electrolyte in batteries. We examine two technologically important cathode materials: LixCoO2 and LixNi0.8Mn0.1Co0.1O2. The surface-to-core transport velocity of Li-phase fronts and volume changes are captured as a function of cycling rate. Additionally, we visualize heterogeneities in the bulk and at agglomerate surfaces during cycling, and image microscopic liquid electrolyte concentration gradients. We discover that surface-limited reactions and intra-agglomerate competing rates control (de)lithiation and structural heterogeneities in agglomerate-based electrodes. Importantly, the conditions under which optical imaging can be performed inside the complex environments of battery electrodes are outlined.

Axonal transport of Frizzled5 by Alcadein α-containing vesicles is associated with kinesin-1.

Alcadein α (Alcα) and amyloid-β protein precursor (APP) are cargo receptors that associate vesicles with kinesin-1. These vesicles, which contain either Alcα or APP, transport various proteins/cargo molecules into axon nerve terminals. Here, we analyzed immune-isolated Alcα- and APP-containing vesicles of adult mouse brains with LC-MS/MS and identified proteins present in vesicles that contained either Alcα or APP. Among these proteins, Frizzled-5 (Fzd5), a Wnt receptor, was detected mainly in Alcα vesicles. Although colocalization ratios of Fzd5 with Alcα are low in the neurites of differentiating neurons by a low expression of Fzd5 in embryonic brains, the suppression of Alcαexpression decreased the localization of Fzd5 in neurites of primary cultured neurons. Furthermore, Fzd5-EGFP expressed in primary cultured neurons was preferentially transported in axons with the transport velocities of Alcα vesicles. In synaptosomal fractions of adult-mice brains that express higher levels of Fzd5, the amount of Fzd5 and the phosphorylation level of calcium/calmodulin-dependent protein kinase-II were reduced in the Alcα-deficient mice. These results suggest that reduced transport of Fzd5 by Alcα-containing vesicles associated with kinesin-1 in axon terminals may impair the response to Wnt ligands in the noncanonical Ca2+-dependent signal transduction pathway at nerve terminals of mature neurons.

A 20:1 synergetic mixture of cafedrine/theodrenaline accelerates particle transport velocity in murine tracheal epithelium via IP3 receptor-associated calcium release.

Background: Mucociliary clearance is a pivotal physiological mechanism that protects the lung by ridding the lower airways of pollution and colonization by pathogens, thereby preventing infections. The fixed 20:1 combination of cafedrine and theodrenaline has been used to treat perioperative hypotension or hypotensive states due to emergency situations since the 1960s. Because mucociliary clearance is impaired during mechanical ventilation and critical illness, the present study aimed to evaluate the influence of cafedrine/theodrenaline on mucociliary clearance. Material and Methods: The particle transport velocity (PTV) of murine trachea preparations was measured as a surrogate for mucociliary clearance under the influence of cafedrine/theodrenaline, cafedrine alone, and theodrenaline alone. Inhibitory substances were applied to elucidate relevant signal transduction cascades. Results: All three applications of the combination of cafedrine/theodrenaline, cafedrine alone, or theodrenaline alone induced a sharp increase in PTV in a concentration-dependent manner with median effective concentrations of 0.46µM (consisting of 9.6µM cafedrine and 0.46µM theodrenaline), 408 and 4μM, respectively. The signal transduction cascades were similar for the effects of both cafedrine and theodrenaline at the murine respiratory epithelium. While PTV remained at its baseline value after non-selective inhibition of β-adrenergic receptors and selective inhibition of β1 receptors, cafedrine/theodrenaline, cafedrine alone, or theodrenaline alone increased PTV despite the inhibition of the protein kinase A. However, IP3 receptor activation was found to be the pivotal mechanism leading to the increase in murine PTV, which was abolished when IP3 receptors were inhibited. Depleting intracellular calcium stores with caffeine confirmed calcium as another crucial messenger altering the PTV after the application of cafedrine/theodrenaline. Discussion: Cafedrine/theodrenaline, cafedrine alone, and theodrenaline alone exert their effects via IP3 receptor-associated calcium release that is ultimately triggered by β1-adrenergic receptor stimulation. Synergistic effects at the β1-adrenergic receptor are highly relevant to alter the PTV of the respiratory epithelium at clinically relevant concentrations. Further investigations are needed to assess the value of cafedrine/theodrenaline-mediated alterations in mucociliary function in clinical practice.

Nitrogen Electrocatalysis: Electrolyte Engineering Strategies to Boost Faradaic Efficiency.

The electrochemical activation of dinitrogen at ambient temperature and pressure for the synthesis of ammonia has drawn increasing attention. The Faradaic Efficiency (FE) as well as ammonia yield in the electrochemical synthesis is far from reaching the requirement of industrial scale production. In aqueous electrolytes, the electron stealing hydrogen evolution reaction (HER) and poor solubility of nitrogen are the two major bottlenecks. As the electrochemical reduction of nitrogen involves proton-coupled electron transfer reaction, the rationally engineered electrolytes are required to boost FE and ammonia yield. In this review, we comprehensively summarize various electrolyte engineering strategies to boost the FE in aqueous and non-aqueous medium and suggest possible approach to further improve the performance. In aqueous medium, the performance can be improved by modulating the electrolyte pH, transport velocity of proton, and water activity. The other strategies involve the use of hybrid and water-in-salt electrolytes, ionic liquids, and non-aqueous electrolytes. The existing aqueous electrolytes are not ideal for industrial scale production. Suppression of HER and enhanced nitrogen solubility have been observed with hybrid and non-aqueous electrolytes. The engineered electrolytes are very promising though the electrochemical activation has several challenges. The outcome of lithium-mediated NRR with engineered non-aqueous electrolyte is highly encouraging.

Anatomy of an Alpine Bedload Transport Event: A Watershed‐Scale Seismic‐Network Perspective

AbstractThe way Alpine rivers mobilize, convey and store coarse material during high‐magnitude events is poorly understood, notably because it is difficult to obtain measurements of bedload transport at the watershed scale. Seismic sensor data, evaluated with appropriate seismic physical models, can provide that missing link by yielding time‐varying estimates of bedload transport albeit with non‐negligible uncertainty. Low cost and ease of installation allow for networks of sensors to be deployed, providing continuous, watershed‐scale insights into bedload transport dynamics. Here, we deploy a network of 24 seismic sensors to estimate coarse material fluxes in a 13.4 km2 Alpine watershed during a high‐magnitude transport event. First, we benchmark the seismic inversion routine with an independent time‐series of bedload transport obtained with a calibrated acoustic system. Then, we apply the procedure to the other seismic sensors across the watershed. Propagation velocities derived from cross‐correlation analysis between spatially consecutive bedload transport time‐series were too high with respect to typical bedload transport velocity suggesting that a faster‐moving water wave (re‐)mobilizes local coarse material. Spatially distributed estimates of bedload transport reveal a relative inefficiency of Alpine watersheds in evacuating coarse material, even during a relatively infrequent high‐magnitude bedload transport event. Significant inputs estimated for some tributaries were rapidly attenuated as the main river crossed less hydraulically efficient reaches. Only a small proportion of the total amount of material mobilized in the watershed was exported at the outlet. Multiple periods of competent flows are likely necessary to evacuate coarse material mobilized throughout the watershed during individual bedload transport events.

Summer Chlorophyll-a Increase Induced by Upwelling off the Northeastern Coast of Hainan Island, South China Sea

There are generally high chlorophyll-a concentrations (Chl-a) where upwelling is prevalent. High Chl-a is often observed in upwelling areas of the northeastern coast of Hainan Island during the summer. Using the satellite remote sensing data, including sea surface temperature, sea surface wind and Chl-a data from 2009 to 2022, we analyze the spatial-temporal and inter-annual variation of Chl-a on the northeastern coast of Hainan Island. Then, the possible influence of environmental factors on Chl-a are further examined by using satellite data, as well as Ekman transport and Ekman pumping velocity derived from the wind products. Finally, the key factors affecting the changes of Chl-a are discussed by correlation analysis. The results show the significant interannual variation of Chl-a in the region, with the maximum of summer Chl-a during the prevalent period of upwelling. The correlation analyses reveal that there is a higher correlation coefficient between the summer Chl-a and the upwelling index (i.e., upwelling regional temperature anomaly), suggesting the role played by upwelling in the summer high Chl-a is more important than the other environmental factors. It is speculated that the summer Chl-a increase is not only influenced by wind-induced upwelling but also by the upwelling caused by tidal mixing, large-scale circulation, topographic changes, and typhoon events.

Locating a droplet on piezoelectric substrate based on a smartphone

In order to detect the position of a droplet on a piezoelectric substrate, a smartphone-based location method is developed. A transportation video is recorded and then analyzed using the smartphone. An algorithm for identifying the droplet in the captured image is presented, and the center distance of the droplet is calculated by analyzing the color information of the image. A black ink solution droplet is demonstrated for determining droplet position using a self-developed app. The results show that the droplet position is 201 pixels at the 11th second and its transportation velocity is 0.37 mm/s from the 2nd second to the 11th second at 27.5 dBm electric signal power.

Material Transport Characteristics in Planetary Roller Melt Granulation.

Melt granulation for improving material handling by modifying particle size distribution offers significant advantages compared to the standard methods of dry and wet granulation in dust reduction, obviating a subsequent drying step. Furthermore, current research in pharmaceutical technology aims for continuous methods, as these have an enhanced potential to reduce product quality fluctuations. Concerning both aspects, the use of a planetary roller granulator is consequential. The process control with these machines benefits from the enhanced ratio of heated surface to processed volume, compared to the usually-applied twin-screw systems. This is related to the unique concept of planetary spindles flowing around a central spindle in a roller cylinder. Herein, the movement pattern defines the transport characteristics, which determine the energy input and overall processing conditions. The aim of this study is to investigate the residence time distribution in planetary roller melt granulation (PRMG) as an indicator for the material transport. By altering feed rate and rotation speed, the fill level in the granulator is adjusted, which directly affects the average transport velocity and mixing volume. The two-compartment model was utilized to reflect these coherences, as the model parameters symbolize the sub-processes of axial material transport and mixing.

Prediction of superionic state in LiH2 at conditions enroute to nuclear fusion

Hydrogen and lithium, along with their compounds, are crucial materials for nuclear fusion research. High-pressure studies have revealed intricate structural transitions in all these materials. However, research on lithium hydrides beyond LiH has mostly focused on the low-temperature regime. Here, we use density functional theory and ab initio molecular dynamics simulations to investigate the behavior of LiH2, a hydrogen-rich compound, near its melting point. Our study is particularly relevant to the low-pressure region of the compression pathway of lithium hydrides toward fusion. We discovered a premelting superionic phase transition in LiH2 that has significant implications for its mass transportation, elastic properties, and sound velocity. The theoretical boundary for the superionic transition and melting temperature was then determined. In contrast, we also found that the primary compound of lithium hydrides, LiH, does not exhibit a superionic transition. These findings have important implications for optimizing the compression path to achieve the ignition condition in inertial confinement fusion research, especially when lithium tritium-deuteride (LiTD) is used as the fuel.

Quantitative testing method of solid-liquid two-phase for unconventional fracturing proppant transport

In unconventional reservoir slickwater fracturing, a large flow rate of slickwater with proppant is injected into the fracture network to create a complex solid-liquid two-phase flow. To obtain the flow pattern, quantitative testing methods must be explored based on conventional proppant transport laydown qualitative observation experiments. Optical visualization of the flow field was achieved by improving the structure of the flat plate fracture experimental unit, followed by particle image data acquisition of the fracturing fluid-proppant two-phase flow field using laser particle image velocimetry on the constructed experimental setup. The image acquisition parameters were optimized based on the proppant particle exposure characteristics, and a method was developed to enhance the proppant-tracer particle image for separation. Based on particle center detection, a model for proppant particle velocity calculation was established based on quasi-rigidity theory, and the validity of the model was verified using an artificial flow field. According to the experimental test and calculation results of the two-phase flow field with different proppant particle sizes, types, and different flow regimes, such as turbulent and laminar flow, the designed device and the established quantitative test and calculation method of the solid-liquid two-phase flow field can better adapt to the testing problem of the proppant transport velocity field in unconventional fracturing, and aid further quantitative studies of the proppant transport law.

Computational Modeling of Substrate-Dependent Mitochondrial Respiration and Bioenergetics in the Heart and Kidney Cortex and Outer Medulla.

Integrated computational modeling provides a mechanistic and quantitative framework to characterize alterations in mitochondrial respiration and bioenergetics in response to different metabolic substrates in-silico. These alterations play critical roles in the pathogenesis of diseases affecting metabolically active organs such as heart and kidney. Therefore, the present study aimed to develop and validate thermodynamically constrained integrated computational models of mitochondrial respiration and bioenergetics in the heart and kidney cortex and outer medulla (OM). The models incorporated the kinetics of major biochemical reactions and transport processes as well as regulatory mechanisms in the mitochondria of these tissues. Intrinsic model parameters such as Michaelis-Menten constants were fixed at previously estimated values, while extrinsic model parameters such as maximal reaction and transport velocities were estimated separately for each tissue. This was achieved by fitting the model solutions to our recently published respirometry data measured in isolated rat heart and kidney cortex and OM mitochondria utilizing various NADH- and FADH2-linked metabolic substrates. The models were validated by predicting additional respirometry and bioenergetics data, which were not used for estimating the extrinsic model parameters. The models were able to predict tissue-specific and substrate-dependent mitochondrial emergent metabolic system properties such as redox states, enzyme and transporter fluxes, metabolite concentrations, membrane potential, and respiratory control index under diverse physiological and pathological conditions. The models were also able to quantitatively characterize differential regulations of NADH- and FADH2-linked metabolic pathways, which contribute differently toward regulations of oxidative phosphorylation and ATP synthesis in the heart and kidney cortex and OM mitochondria.