WorldWideScience

Sample records for adaptive metabolism reduction

  1. Alzheimer's disease and natural cognitive aging may represent adaptive metabolism reduction programs

    Reser Jared

    2009-02-01

    Full Text Available Abstract The present article examines several lines of converging evidence suggesting that the slow and insidious brain changes that accumulate over the lifespan, resulting in both natural cognitive aging and Alzheimer's disease (AD, represent a metabolism reduction program. A number of such adaptive programs are known to accompany aging and are thought to have decreased energy requirements for ancestral hunter-gatherers in their 30s, 40s and 50s. Foraging ability in modern hunter-gatherers declines rapidly, more than a decade before the average terminal age of 55 years. Given this, the human brain would have been a tremendous metabolic liability that must have been advantageously tempered by the early cellular and molecular changes of AD which begin to accumulate in all humans during early adulthood. Before the recent lengthening of life span, individuals in the ancestral environment died well before this metabolism reduction program resulted in clinical AD, thus there was never any selective pressure to keep adaptive changes from progressing to a maladaptive extent. Aging foragers may not have needed the same cognitive capacities as their younger counterparts because of the benefits of accumulated learning and life experience. It is known that during both childhood and adulthood metabolic rate in the brain decreases linearly with age. This trend is thought to reflect the fact that children have more to learn. AD "pathology" may be a natural continuation of this trend. It is characterized by decreasing cerebral metabolism, selective elimination of synapses and reliance on accumulating knowledge (especially implicit and procedural over raw brain power (working memory. Over decades of subsistence, the behaviors of aging foragers became routinized, their motor movements automated and their expertise ingrained to a point where they no longer necessitated the first-rate working memory they possessed when younger and learning actively. Alzheimer

  2. Metabolic Adaptation to Muscle Ischemia

    Cabrera, Marco E.; Coon, Jennifer E.; Kalhan, Satish C.; Radhakrishnan, Krishnan; Saidel, Gerald M.; Stanley, William C.

    2000-01-01

    Although all tissues in the body can adapt to varying physiological/pathological conditions, muscle is the most adaptable. To understand the significance of cellular events and their role in controlling metabolic adaptations in complex physiological systems, it is necessary to link cellular and system levels by means of mechanistic computational models. The main objective of this work is to improve understanding of the regulation of energy metabolism during skeletal/cardiac muscle ischemia by combining in vivo experiments and quantitative models of metabolism. Our main focus is to investigate factors affecting lactate metabolism (e.g., NADH/NAD) and the inter-regulation between carbohydrate and fatty acid metabolism during a reduction in regional blood flow. A mechanistic mathematical model of energy metabolism has been developed to link cellular metabolic processes and their control mechanisms to tissue (skeletal muscle) and organ (heart) physiological responses. We applied this model to simulate the relationship between tissue oxygenation, redox state, and lactate metabolism in skeletal muscle. The model was validated using human data from published occlusion studies. Currently, we are investigating the difference in the responses to sudden vs. gradual onset ischemia in swine by combining in vivo experimental studies with computational models of myocardial energy metabolism during normal and ischemic conditions.

  3. Unveiling the Metabolic Pathways Associated with the Adaptive Reduction of Cell Size During Vibrio harveyi Persistence in Seawater Microcosms.

    Kaberdin, Vladimir R; Montánchez, Itxaso; Parada, Claudia; Orruño, Maite; Arana, Inés; Barcina, Isabel

    2015-10-01

    Owing to their ubiquitous presence and ability to act as primary or opportunistic pathogens, Vibrio species greatly contribute to the diversity and evolution of marine ecosystems. This study was aimed at unveiling the cellular strategies enabling the marine gammaproteobacterium Vibrio harveyi to adapt and persist in natural aquatic systems. We found that, although V. harveyi incubation in seawater microcosm at 20 °C for 2 weeks did not change cell viability and culturability, it led to a progressive reduction in the average cell size. Microarray analysis revealed that this morphological change was accompanied by a profound decrease in gene expression affecting the central carbon metabolism, major biosynthetic pathways, and energy production. In contrast, V. harveyi elevated expression of genes closely linked to the composition and function of cell envelope. In addition to triggering lipid degradation via the β-oxidation pathway and apparently promoting the use of endogenous fatty acids as a major energy and carbon source, V. harveyi upregulated genes involved in ancillary mechanisms important for sustaining iron homeostasis, cell resistance to the toxic effect of reactive oxygen species, and recycling of amino acids. The above adaptation mechanisms and morphological changes appear to represent the major hallmarks of the initial V. harveyi response to starvation. PMID:25903990

  4. Adaptive Noise Reduction System

    Ivana Ropuš

    2013-01-01

    Full Text Available Noise is an all-present environment pollutant, considered to be one of the greatest contemporary pollutants. World-wide, co-ordinated actions are conducted in order to develop systems which minimise the noise influence onto society.In this article we argue that novel approach to suppression of influence of noise is useful. Furthermore, we argue that the efficient approach is formulation of the efficient, broadly applicable, ubiquituous, adaptive noise-protection system. The approach combines the natural noise-protection form based on plants with the artificially formed coatings.Elements of the system are discussed, its formation and maintenance analysed and perspectives conjectured.

  5. Mitochondrial function adaptations to changed metabolic conditions

    Bakkman, Linda

    2010-01-01

    The skeletal muscle mitochondria play a decisive role for the metabolic capacity of the body. A capability to adapt to changed metabolic conditions and energy demands is crucial for weight control and physical exercise. The aim of this thesis was to describe how the mitochondria adapt its function to different environmental conditions and changed metabolic demands. In study I, the aim was to evaluate mitochondrial adaptations to hypoxic exercise. The effect of one-legged...

  6. Adaptive diversity: hormones and metabolism in freshwaters.

    Laudet, Vincent

    2010-12-01

    Genes underlying the evolution of morphological traits have recently been identified in a number of model species. In the stickleback, the metabolic adaptations to a freshwater habitat have now been linked to a well-known hormonal system. PMID:21145015

  7. Metabolic adaptations for desert survival in the Bedouin goat.

    Choshniak, I; Ben-Kohav, N; Taylor, C R; Robertshaw, D; Barnes, R J; Dobson, A; Belkin, V; Shkolnik, A

    1995-05-01

    Energy conservation is a key adaptation for desert survival in the Bedouin goat. When food is scarce, metabolism is reduced and body weight can be maintained indefinitely on less than one-half of normal intake. We hypothesized that metabolism would be turned down during both rest and exercise, but it was not. It was low when animals rested and returned to normal during exercise. We expected catecholamines and thyroid hormones would modulate metabolism, but they did not. The reduction in metabolism preceded any change in thyroid hormone concentrations, and infusions of epinephrine did not restore reduced metabolism to normal levels. Finally, we expected the gut would be the major organ system involved in the metabolic reduction because less food is eaten, processed, and absorbed. Contrary to our expectations, we found that muscle is the primary organ system responsible for the reduction. It appears that the adaptations of the Bedouin goat for surviving on limited food supplies involve different organ systems and different modulators to reduce metabolism from those known for other mammals. PMID:7771568

  8. Adaptive evolution of complex innovations through stepwise metabolic niche expansion.

    Szappanos, Balázs; Fritzemeier, Jonathan; Csörgő, Bálint; Lázár, Viktória; Lu, Xiaowen; Fekete, Gergely; Bálint, Balázs; Herczeg, Róbert; Nagy, István; Notebaart, Richard A; Lercher, Martin J; Pál, Csaba; Papp, Balázs

    2016-01-01

    A central challenge in evolutionary biology concerns the mechanisms by which complex metabolic innovations requiring multiple mutations arise. Here, we propose that metabolic innovations accessible through the addition of a single reaction serve as stepping stones towards the later establishment of complex metabolic features in another environment. We demonstrate the feasibility of this hypothesis through three complementary analyses. First, using genome-scale metabolic modelling, we show that complex metabolic innovations in Escherichia coli can arise via changing nutrient conditions. Second, using phylogenetic approaches, we demonstrate that the acquisition patterns of complex metabolic pathways during the evolutionary history of bacterial genomes support the hypothesis. Third, we show how adaptation of laboratory populations of E. coli to one carbon source facilitates the later adaptation to another carbon source. Our work demonstrates how complex innovations can evolve through series of adaptive steps without the need to invoke non-adaptive processes. PMID:27197754

  9. An adaptive composite quantile approach to dimension reduction

    Kong, Efang; Xia, Yingcun

    2014-01-01

    Sufficient dimension reduction [J. Amer. Statist. Assoc. 86 (1991) 316–342] has long been a prominent issue in multivariate nonparametric regression analysis. To uncover the central dimension reduction space, we propose in this paper an adaptive composite quantile approach. Compared to existing methods, (1) it requires minimal assumptions and is capable of revealing all dimension reduction directions; (2) it is robust against outliers and (3) it is structure-adaptive, thus more efficient. Asy...

  10. AN ADAPTIVE COMPOSITE QUANTILE APPROACH TO DIMENSION REDUCTION

    Kong, Efang

    2014-01-01

    Su�cient dimension reduction [Li (1991)] has long been a promi- nent issue in multivariate nonparametric regression analysis. To un- cover the central dimension reduction space, we propose in this pa- per an adaptive composite quantile approach. Compared to existing methods, (1) it requires minimal assumptions and is capable of reveal- ing all dimension reduction directions; (2) it is robust against outliers; and (3) it is structure-adaptive, thus more e�cient. Asymptotic re...

  11. Adaptive Liners for Broadband Noise Reduction Project

    National Aeronautics and Space Administration — This project will combine the advantages of adaptive materials with the simplistic passive design of state-of-the-art acoustic liners to provide the ability to tune...

  12. Metabolism as means for hypoxia adaptation: metabolic profiling and flux balance analysis

    Paternostro Giovanni

    2009-09-01

    Full Text Available Abstract Background Cellular hypoxia is a component of many diseases, but mechanisms of global hypoxic adaptation and resistance are not completely understood. Previously, a population of Drosophila flies was experimentally selected over several generations to survive a chronically hypoxic environment. NMR-based metabolomics, combined with flux-balance simulations of genome-scale metabolic networks, can generate specific hypotheses for global reaction fluxes within the cell. We applied these techniques to compare metabolic activity during acute hypoxia in muscle tissue of adapted versus "naïve" control flies. Results Metabolic profiles were gathered for adapted and control flies after exposure to acute hypoxia using 1H NMR spectroscopy. Principal Component Analysis suggested that the adapted flies are tuned to survive a specific oxygen level. Adapted flies better tolerate acute hypoxic stress, and we explored the mechanisms of this tolerance using a flux-balance model of central metabolism. In the model, adapted flies produced more ATP per glucose and created fewer protons than control flies, had lower pyruvate carboxylase flux, and had greater usage of Complex I over Complex II. Conclusion We suggest a network-level hypothesis of metabolic regulation in hypoxia-adapted flies, in which lower baseline rates of biosynthesis in adapted flies draws less anaplerotic flux, resulting in lower rates of glycolysis, less acidosis, and more efficient use of substrate during acute hypoxic stress. In addition we suggest new specific hypothesis, which were found to be consistent with existing data.

  13. Fermentation and hydrogen metabolism affect uranium reduction by clostridia.

    Gao, Weimin; Francis, Arokiasamy J

    2013-01-01

    Previously, it has been shown that not only is uranium reduction under fermentation condition common among clostridia species, but also the strains differed in the extent of their capability and the pH of the culture significantly affected uranium(VI) reduction. In this study, using HPLC and GC techniques, metabolic properties of those clostridial strains active in uranium reduction under fermentation conditions have been characterized and their effects on capability variance of uranium reduction discussed. Then, the relationship between hydrogen metabolism and uranium reduction has been further explored and the important role played by hydrogenase in uranium(VI) and iron(III) reduction by clostridia demonstrated. When hydrogen was provided as the headspace gas, uranium(VI) reduction occurred in the presence of whole cells of clostridia. This is in contrast to that of nitrogen as the headspace gas. Without clostridia cells, hydrogen alone could not result in uranium(VI) reduction. In alignment with this observation, it was also found that either copper(II) addition or iron depletion in the medium could compromise uranium reduction by clostridia. In the end, a comprehensive model was proposed to explain uranium reduction by clostridia and its relationship to the overall metabolism especially hydrogen (H2) production. PMID:25937978

  14. Fermentation and Hydrogen Metabolism Affect Uranium Reduction by Clostridia

    Weimin Gao; Francis, Arokiasamy J.

    2013-01-01

    Previously, it has been shown that not only is uranium reduction under fermentation condition common among clostridia species, but also the strains differed in the extent of their capability and the pH of the culture significantly affected uranium(VI) reduction. In this study, using HPLC and GC techniques, metabolic properties of those clostridial strains active in uranium reduction under fermentation conditions have been characterized and their effects on capability variance of uranium reduc...

  15. Musical noise reduction using an adaptive filter

    Hanada, Takeshi; Murakami, Takahiro; Ishida, Yoshihisa; Hoya, Tetsuya

    2003-10-01

    This paper presents a method for reducing a particular noise (musical noise). The musical noise is artificially produced by Spectral Subtraction (SS), which is one of the most conventional methods for speech enhancement. The musical noise is the tin-like sound and annoying in human auditory. We know that the duration of the musical noise is considerably short in comparison with that of speech, and that the frequency components of the musical noise are random and isolated. In the ordinary SS-based methods, the musical noise is removed by the post-processing. However, the output of the ordinary post-processing is delayed since the post-processing uses the succeeding frames. In order to improve this problem, we propose a novel method using an adaptive filter. In the proposed system, the observed noisy signal is used as the input signal to the adaptive filter and the output of SS is used as the reference signal. In this paper we exploit the normalized LMS (Least Mean Square) algorithm for the adaptive filter. Simulation results show that the proposed method has improved the intelligibility of the enhanced speech in comparison with the conventional method.

  16. Energetic Metabolism and Biochemical Adaptation: A Bird Flight Muscle Model

    Rioux, Pierre; Blier, Pierre U.

    2006-01-01

    The main objective of this class experiment is to measure the activity of two metabolic enzymes in crude extract from bird pectoral muscle and to relate the differences to their mode of locomotion and ecology. The laboratory is adapted to stimulate the interest of wildlife management students to biochemistry. The enzymatic activities of cytochrome…

  17. Sox17 regulates liver lipid metabolism and adaptation to fasting.

    Rommelaere, Samuel; Millet, Virginie; Vu Manh, Thien-Phong; Gensollen, Thomas; Andreoletti, Pierre; Cherkaoui-Malki, Mustapha; Bourges, Christophe; Escalière, Bertrand; Du, Xin; Xia, Yu; Imbert, Jean; Beutler, Bruce; Kanai, Yoshiakira; Malissen, Bernard; Malissen, Marie; Tailleux, Anne; Staels, Bart; Galland, Franck; Naquet, Philippe

    2014-01-01

    Liver is a major regulator of lipid metabolism and adaptation to fasting, a process involving PPARalpha activation. We recently showed that the Vnn1 gene is a PPARalpha target gene in liver and that release of the Vanin-1 pantetheinase in serum is a biomarker of PPARalpha activation. Here we set up a screen to identify new regulators of adaptation to fasting using the serum Vanin-1 as a marker of PPARalpha activation. Mutagenized mice were screened for low serum Vanin-1 expression. Functional interactions with PPARalpha were investigated by combining transcriptomic, biochemical and metabolic approaches. We characterized a new mutant mouse in which hepatic and serum expression of Vanin-1 is depressed. This mouse carries a mutation in the HMG domain of the Sox17 transcription factor. Mutant mice display a metabolic phenotype featuring lipid abnormalities and inefficient adaptation to fasting. Upon fasting, a fraction of the PPARα-driven transcriptional program is no longer induced and associated with impaired fatty acid oxidation. The transcriptional phenotype is partially observed in heterozygous Sox17+/- mice. In mutant mice, the fasting phenotype but not all transcriptomic signature is rescued by the administration of the PPARalpha agonist fenofibrate. These results identify a novel role for Sox17 in adult liver as a modulator of the metabolic adaptation to fasting. PMID:25141153

  18. Global network reorganization during dynamic adaptations of Bacillus subtilis metabolism

    Buescher, Joerg Martin; Liebermeister, Wolfram; Jules, Matthieu;

    2012-01-01

    known transcription regulation network. Interactions across multiple levels of regulation were involved in adaptive changes that could also be achieved by controlling single genes. Our analysis suggests that global trade-offs and evolutionary constraints provide incentives to favor complex control......Adaptation of cells to environmental changes requires dynamic interactions between metabolic and regulatory networks, but studies typically address only one or a few layers of regulation. For nutritional shifts between two preferred carbon sources of Bacillus subtilis, we combined statistical and...... model-based data analyses of dynamic transcript, protein, and metabolite abundances and promoter activities. Adaptation to malate was rapid and primarily controlled posttranscriptionally compared with the slow, mainly transcriptionally controlled adaptation to glucose that entailed nearly half of the...

  19. Increased plasma leptin attenuates adaptive metabolism in early lactating dairy cows.

    Ehrhardt, Richard A; Foskolos, Andreas; Giesy, Sarah L; Wesolowski, Stephanie R; Krumm, Christopher S; Butler, W Ronald; Quirk, Susan M; Waldron, Matthew R; Boisclair, Yves R

    2016-05-01

    Mammals meet the increased nutritional demands of lactation through a combination of increased feed intake and a collection of adaptations known as adaptive metabolism (e.g., glucose sparing via insulin resistance, mobilization of endogenous reserves, and increased metabolic efficiency via reduced thyroid hormones). In the modern dairy cow, adaptive metabolism predominates over increased feed intake at the onset of lactation and develops concurrently with a reduction in plasma leptin. To address the role of leptin in the adaptive metabolism of early lactation, we asked which adaptations could be countered by a constant 96-h intravenous infusion of human leptin (hLeptin) starting on day 8 of lactation. Compared to saline infusion (Control), hLeptin did not alter energy intake or milk energy output but caused a modest increase in body weight loss. hLeptin reduced plasma glucose by 9% and hepatic glycogen content by 73%, and these effects were associated with a 17% increase in glucose disposal during an insulin tolerance test. hLeptin attenuated the accumulation of triglyceride in the liver by 28% in the absence of effects on plasma levels of the anti-lipolytic hormone insulin or plasma levels of free fatty acids, a marker of lipid mobilization from adipose tissue. Finally, hLeptin increased the plasma concentrations of T4 and T3 by nearly 50% without affecting other neurally regulated hormones (i.e., cortisol and luteinizing hormone (LH)). Overall these data implicate the periparturient reduction in plasma leptin as one of the signals promoting conservation of glucose and energy at the onset of lactation in the energy-deficient dairy cow. PMID:26957637

  20. Sox17 Regulates Liver Lipid Metabolism and Adaptation to Fasting

    Rommelaere, Samuel; Millet, Virginie; Vu Manh, Thien-Phong; Gensollen, Thomas; Andreoletti, Pierre; Cherkaoui-Malki, Mustapha; Bourges, Christophe; Escalière, Bertrand; Du, Xin; Xia, Yu; Imbert, Jean; Beutler, Bruce; Kanai, Yoshiakira; Malissen, Bernard; Malissen, Marie

    2014-01-01

    Liver is a major regulator of lipid metabolism and adaptation to fasting, a process involving PPARalpha activation. We recently showed that the Vnn1 gene is a PPARalpha target gene in liver and that release of the Vanin-1 pantetheinase in serum is a biomarker of PPARalpha activation. Here we set up a screen to identify new regulators of adaptation to fasting using the serum Vanin-1 as a marker of PPARalpha activation. Mutagenized mice were screened for low serum Vanin-1 expression. Functional...

  1. Alterations in cancer cell metabolism: the Warburg effect and metabolic adaptation.

    Asgari, Yazdan; Zabihinpour, Zahra; Salehzadeh-Yazdi, Ali; Schreiber, Falk; Masoudi-Nejad, Ali

    2015-05-01

    The Warburg effect means higher glucose uptake of cancer cells compared to normal tissues, whereas a smaller fraction of this glucose is employed for oxidative phosphorylation. With the advent of high throughput technologies and computational systems biology, cancer cell metabolism has been reinvestigated over the last decades toward identifying various events underlying "how" and "why" a cancer cell employs aerobic glycolysis. Significant progress has been shaped to revise the Warburg effect. In this study, we have integrated the gene expression of 13 different cancer cells with the genome-scale metabolic network of human (Recon1) based on the E-Flux method, and analyzed them based on constraint-based modeling. Results show that regardless of significant up- and down-regulated metabolic genes, the distribution of metabolic changes is similar in different cancer types. These findings support the theory that the Warburg effect is a consequence of metabolic adaptation in cancer cells. PMID:25773945

  2. Adaptive changes in basal metabolic rate and thermogenesis in chronic undernutrition

    Metabolic adaptation during chronic undernutrition represents a complex integration of several processes which affect the total energy expenditure of the individual. Basal metabolic rate (BMR) is reduced; reductions in BMR per unit fat free mass (FFM) is difficult to demonstrate. BMR changes in undernutrition reflect the low body weight as well as alterations in the composition of the FFM; more specifically changes in the ratio of viscera to muscle compartments of the FFM. Thermogenic responses to norepinephrine are transiently suppressed but recover rapidly on repeated stimulation. Dietary thermogenesis is enhanced possible the result of increases in tissue synthesis within the body. Changes in BMR and thermogenesis suggestive of an increase in metabolic efficiency is thus difficult to demonstrate in chronic undernutrition. (author). 15 refs, 2 figs, 7 tabs

  3. An adaptive Kalman filter for speckle reductions in ultrasound images

    Speckle is the term used to describe the granular appearance found in ultrasound images. The presence of speckle reduces the diagnostic potential of the echographic technique because it tends to mask small inhomogeneities of the investigated tissue. We developed a new method of speckle reductions that utilizes an adaptive one-dimensional Kalman filter based on the assumption that the observed image can be considered as a superimposition of speckle on a ''true images''. The filter adaptivity, necessary to avoid loss of resolution, has been obtained by statistical considerations on the local signal variations. The results of the applications of this particular Kalman filter, both on A-Mode and B-MODE images, show a significant speckle reduction

  4. AN INVESTIGATION OF FLICKER REDUCTION USING AN ADAPTIVE VAR COMPENSATOR

    Jatskevich, Juri V.; Wasynczuk, Oleg

    1997-01-01

    A detailed computer model of a three-phase power network which includes inductive loads, resistance welders and an Adaptive Var Compensator (AVC) has been developed. The system configuration and parameters correspond to an irrdustrial customer served by a large electric utility. Welder operation produces severe cyclic flicker which leads to customer complaints. Computer studies have been conducted to determine the effectiveness of the AVC on the reduction of observable flicker at neighboring ...

  5. [Phase changes of energy metabolism during adaptation to immobilization stress].

    Portnichenko, V I; Nosar, V I; Honchar, O O; Opanasenko, H V; Hlazyrin, I D; Man'kovs'ka, I M

    2014-01-01

    In stress, it was showed the organ and tissue changes associated with damage by lipid peroxides, and the disrupted barrier function. As a consequence, it was to lead to a syndrome of "stress-induced lung" and violation of oxygen delivery to the tissues and hypoxia. Purpose of the study was to investigate the dynamics of changes in gas exchange, blood glucose, body temperature, oxidant and antioxidant system activity, as well as mitochondrial respiration by Chance under the influence of chronic stress (6-hour immobilization daily for 3 weeks). It was identified 4 phase changes of energy metabolism in the dynamics of chronic stress. In the first phase, hypomethabolic, instability oxidative metabolism, decreased oxidation of NAD-dependent substrates, significant elevation of FAD-dependent substrates oxidation and low MRU were found. The activity of superoxide dismutase (MnSOD) was increased; it was occurred on a background low activity of glutathione peroxidase, and of misbalanced antioxidant system. After seven immobilizations, second phase-shift in energy metabolism, was observed, and then the third phase (hypermetabolic) started. It was characterized by gradual increase in oxidative metabolism, the restoration of oxidation of NAD-dependent substrates, MRU, as well as optimizing balance of oxidant and antioxidant systems. The fourth phase was started after 15 immobilizations, and characterized by the development of adaptive reactions expressed in increased tolerance of energy metabolism to the impact of immobilization. The results are correlated with changes in the dynamics of blood corticosterone. Thus, it was found the phase character of the energy metabolism rebuilding during the chronic stress. PMID:25566668

  6. Adaptive model reduction for nonsmooth discrete element simulation

    Servin, Martin; Wang, Da

    2016-03-01

    A method for adaptive model order reduction for nonsmooth discrete element simulation is developed and analysed in numerical experiments. Regions of the granular media that collectively move as rigid bodies are substituted with rigid bodies of the corresponding shape and mass distribution. The method also support particles merging with articulated multibody systems. A model approximation error is defined and used to derive conditions for when and where to apply reduction and refinement back into particles and smaller rigid bodies. Three methods for refinement are proposed and tested: prediction from contact events, trial solutions computed in the background and using split sensors. The computational performance can be increased by 5-50 times for model reduction level between 70-95 %.

  7. Adaptive model reduction for nonsmooth discrete element simulation

    Servin, Martin

    2015-01-01

    A method for adaptive model order reduction for nonsmooth discrete element simulation is developed and analysed in numerical experiments. Regions of the granular media that collectively move as rigid bodies are substituted with rigid bodies of the corresponding shape and mass distribution. The method also support particles merging with articulated multibody systems. A model approximation error is defined used for deriving and conditions for when and where to apply model reduction and refinement back into particles and smaller rigid bodies. Three methods for refinement are proposed and tested: prediction from contact events, trial solutions computed in the background and using split sensors. The computational performance can be increased by 5 - 50 times for model reduction level between 70 - 95 %.

  8. Adaptation from interactions between metabolism and behaviour: self-sensitive behaviour in protocells

    Egbert, Matthew

    2012-01-01

    This thesis considers the relationship between adaptive behaviour and metabolism, using theoretical arguments supported by computational models to demonstrate mechanisms of adaptation that are uniquely available to systems based upon the metabolic organisation of self-production. It is argued how, by being sensitive to their metabolic viability, an organism can respond to the quality of its environment with respect to its metabolic well-being. This makes possible simple but powerful ‘self...

  9. Integration of Posttranscriptional Gene Networks into Metabolic Adaptation and Biofilm Maturation in Candida albicans

    Verma-Gaur, Jiyoti; Qu, Yue; Harrison, Paul F.; Lo, Tricia L.; Quenault, Tara; Dagley, Michael J.; Bellousoff, Matthew; Powell, David R; Beilharz, Traude H.; Traven, Ana

    2015-01-01

    The yeast Candida albicans is a human commensal and opportunistic pathogen. Although both commensalism and pathogenesis depend on metabolic adaptation, the regulatory pathways that mediate metabolic processes in C. albicans are incompletely defined. For example, metabolic change is a major feature that distinguishes community growth of C. albicans in biofilms compared to suspension cultures, but how metabolic adaptation is functionally interfaced with the structural and gene regulatory change...

  10. Emergent Adaptive Noise Reduction from Communal Cooperation of Sensor Grid

    Jones, Kennie H.; Jones, Michael G.; Nark, Douglas M.; Lodding, Kenneth N.

    2010-01-01

    In the last decade, the realization of small, inexpensive, and powerful devices with sensors, computers, and wireless communication has promised the development of massive sized sensor networks with dense deployments over large areas capable of high fidelity situational assessments. However, most management models have been based on centralized control and research has concentrated on methods for passing data from sensor devices to the central controller. Most implementations have been small but, as it is not scalable, this methodology is insufficient for massive deployments. Here, a specific application of a large sensor network for adaptive noise reduction demonstrates a new paradigm where communities of sensor/computer devices assess local conditions and make local decisions from which emerges a global behaviour. This approach obviates many of the problems of centralized control as it is not prone to single point of failure and is more scalable, efficient, robust, and fault tolerant

  11. Adaptive radial basis function mesh deformation using data reduction

    Gillebaart, T.; Blom, D. S.; van Zuijlen, A. H.; Bijl, H.

    2016-09-01

    Radial Basis Function (RBF) mesh deformation is one of the most robust mesh deformation methods available. Using the greedy (data reduction) method in combination with an explicit boundary correction, results in an efficient method as shown in literature. However, to ensure the method remains robust, two issues are addressed: 1) how to ensure that the set of control points remains an accurate representation of the geometry in time and 2) how to use/automate the explicit boundary correction, while ensuring a high mesh quality. In this paper, we propose an adaptive RBF mesh deformation method, which ensures the set of control points always represents the geometry/displacement up to a certain (user-specified) criteria, by keeping track of the boundary error throughout the simulation and re-selecting when needed. Opposed to the unit displacement and prescribed displacement selection methods, the adaptive method is more robust, user-independent and efficient, for the cases considered. Secondly, the analysis of a single high aspect ratio cell is used to formulate an equation for the correction radius needed, depending on the characteristics of the correction function used, maximum aspect ratio, minimum first cell height and boundary error. Based on the analysis two new radial basis correction functions are derived and proposed. This proposed automated procedure is verified while varying the correction function, Reynolds number (and thus first cell height and aspect ratio) and boundary error. Finally, the parallel efficiency is studied for the two adaptive methods, unit displacement and prescribed displacement for both the CPU as well as the memory formulation with a 2D oscillating and translating airfoil with oscillating flap, a 3D flexible locally deforming tube and deforming wind turbine blade. Generally, the memory formulation requires less work (due to the large amount of work required for evaluating RBF's), but the parallel efficiency reduces due to the limited

  12. Adaptive control of an active seat for occupant vibration reduction

    Gan, Zengkang; Hillis, Andrew J.; Darling, Jocelyn

    2015-08-01

    The harmful effects on human performance and health caused by unwanted vibration from vehicle seats are of increasing concern. This paper presents an active seat system to reduce the vibration level transmitted to the seat pan and the occupants' body under low frequency periodic excitation. Firstly, the detail of the mechanical structure is given and the active seat dynamics without external load are characterized by vibration transmissibility and frequency responses under different excitation forces. Owing the nonlinear and time-varying behaviour of the proposed system, a Filtered-x least-mean-square (FXLMS) adaptive control algorithm with on-line Fast-block LMS (FBLMS) identification process is employed to manage the system operation for high vibration cancellation performance. The effectiveness of the active seat system is assessed through real-time experimental tests using different excitation profiles. The system identification results show that an accurate estimation of the secondary path is achieved by using the FBLMS on-line technique. Substantial reduction is found for cancelling periodic vibration containing single and multiple frequencies. Additionally, the robustness and stability of the control system are validated through transient switching frequency tests.

  13. A striking reduction of simple loudness adaptation in autism

    Lawson, Rebecca P.; Jessica Aylward; Sarah White; Geraint Rees

    2015-01-01

    Reports of sensory disturbance, such as loudness sensitivity or sound intolerance, are ubiquitous in Autism Spectrum Disorder (ASD) but a mechanistic explanation for these perceptual differences is lacking. Here we tested adaptation to loudness, a process that regulates incoming sensory input, in adults with ASD and matched controls. Simple loudness adaptation (SLA) is a fundamental adaptive process that reduces the subjective loudness of quiet steady-state sounds in the environment over time...

  14. Cold adaptation increases rates of nutrient flow and metabolic plasticity during cold exposure in Drosophila melanogaster.

    Williams, Caroline M; McCue, Marshall D; Sunny, Nishanth E; Szejner-Sigal, Andre; Morgan, Theodore J; Allison, David B; Hahn, Daniel A

    2016-09-14

    Metabolic flexibility is an important component of adaptation to stressful environments, including thermal stress and latitudinal adaptation. A long history of population genetic studies suggest that selection on core metabolic enzymes may shape life histories by altering metabolic flux. However, the direct relationship between selection on thermal stress hardiness and metabolic flux has not previously been tested. We investigated flexibility of nutrient catabolism during cold stress in Drosophila melanogaster artificially selected for fast or slow recovery from chill coma (i.e. cold-hardy or -susceptible), specifically testing the hypothesis that stress adaptation increases metabolic turnover. Using (13)C-labelled glucose, we first showed that cold-hardy flies more rapidly incorporate ingested carbon into amino acids and newly synthesized glucose, permitting rapid synthesis of proline, a compound shown elsewhere to improve survival of cold stress. Second, using glucose and leucine tracers we showed that cold-hardy flies had higher oxidation rates than cold-susceptible flies before cold exposure, similar oxidation rates during cold exposure, and returned to higher oxidation rates during recovery. Additionally, cold-hardy flies transferred compounds among body pools more rapidly during cold exposure and recovery. Increased metabolic turnover may allow cold-adapted flies to better prepare for, resist and repair/tolerate cold damage. This work illustrates for the first time differences in nutrient fluxes associated with cold adaptation, suggesting that metabolic costs associated with cold hardiness could invoke resource-based trade-offs that shape life histories. PMID:27605506

  15. Beyond Reduction: Climate Change Adaptation Planning for Universities and Colleges

    Owen, Rochelle; Fisher, Erica; McKenzie, Kyle

    2013-01-01

    Purpose: The purpose of this paper is to outline a unique six-step process for the inclusion of climate change adaption goals and strategies in a University Climate Change Plan. Design/methodology/approach: A mixed-method approach was used to gather data on campus climate change vulnerabilities and adaption strategies. A literature review…

  16. Metabolic insight into mechanisms of high-altitude adaptation in Tibetans

    Ge, Ri-Li; Simonson, Tatum S.; Cooksey, Robert C.; Tanna, Uran; Qin, Ga; Huff, Chad D.; WITHERSPOON, DAVID J.; Xing, Jinchuan; Zhengzhong, Bai; Prchal, Josef T.; Jorde, Lynn B.; McClain, Donald A.

    2012-01-01

    Recent studies have identified genes involved in high-altitude adaptation in Tibetans. Genetic variants/haplotypes within regions containing three of these genes (EPAS1, EGLN1, and PPARA) are associated with relatively decreased hemoglobin levels observed in Tibetans at high altitude, providing corroborative evidence for genetic adaptation to this extreme environment. The mechanisms that afford adaptation to high-altitude hypoxia, however, remain unclear. Considering the strong metabolic dema...

  17. Regulatory and metabolic networks for the adaptation of Pseudomonas aeruginosa biofilms to urinary tract-like conditions.

    Petra Tielen

    Full Text Available Biofilms of the Gram-negative bacterium Pseudomonas aeruginosa are one of the major causes of complicated urinary tract infections with detrimental outcome. To develop novel therapeutic strategies the molecular adaption strategies of P. aeruginosa biofilms to the conditions of the urinary tract were investigated thoroughly at the systems level using transcriptome, proteome, metabolome and enzyme activity analyses. For this purpose biofilms were grown anaerobically in artificial urine medium (AUM. Obtained data were integrated bioinformatically into gene regulatory and metabolic networks. The dominating response at the transcriptome and proteome level was the adaptation to iron limitation via the broad Fur regulon including 19 sigma factors and up to 80 regulated target genes or operons. In agreement, reduction of the iron cofactor-dependent nitrate respiratory metabolism was detected. An adaptation of the central metabolism to lactate, citrate and amino acid as carbon sources with the induction of the glyoxylate bypass was observed, while other components of AUM like urea and creatinine were not used. Amino acid utilization pathways were found induced, while fatty acid biosynthesis was reduced. The high amounts of phosphate found in AUM explain the reduction of phosphate assimilation systems. Increased quorum sensing activity with the parallel reduction of chemotaxis and flagellum assembly underscored the importance of the biofilm life style. However, reduced formation of the extracellular polysaccharide alginate, typical for P. aeruginosa biofilms in lungs, indicated a different biofilm type for urinary tract infections. Furthermore, the obtained quorum sensing response results in an increased production of virulence factors like the extracellular lipase LipA and protease LasB and AprA explaining the harmful cause of these infections.

  18. Exercise, PGC-1α and metabolic adaptation in skeletal muscle

    Yan, Zhen

    2009-01-01

    Endurance exercise promotes skeletal muscle adaptation, and exercise-induced peroxisome proliferator-activated receptor γ co-activator-1α (Pgc-1α) gene expression may play a pivotal role in the adaptive processes. Recent applications of mouse genetic models and in vivo imaging in exercise studies started to delineate the signaling-transcription pathways that are involved in the regulation of the Pgc-1α gene. These studies revealed the importance of p38 mitogen-activated protein kinase (MAPK)/...

  19. Perilipin 5 is dispensable for normal substrate metabolism and in the adaptation of skeletal muscle to exercise training.

    Mohktar, Ruzaidi A M; Montgomery, Magda K; Murphy, Robyn M; Watt, Matthew J

    2016-07-01

    Cytoplasmic lipid droplets provide a reservoir for triglyceride storage and are a central hub for fatty acid trafficking in cells. The protein perilipin 5 (PLIN5) is highly expressed in oxidative tissues such as skeletal muscle and regulates lipid metabolism by coordinating the trafficking and the reversible interactions of effector proteins at the lipid droplet. PLIN5 may also regulate mitochondrial function, although this remains unsubstantiated. Hence, the aims of this study were to examine the role of PLIN5 in the regulation of skeletal muscle substrate metabolism during acute exercise and to determine whether PLIN5 is required for the metabolic adaptations and enhancement in exercise tolerance following endurance exercise training. Using muscle-specific Plin5 knockout mice (Plin5(MKO)), we show that PLIN5 is dispensable for normal substrate metabolism during exercise, as reflected by levels of blood metabolites and rates of glycogen and triglyceride depletion that were indistinguishable from control (lox/lox) mice. Plin5(MKO) mice exhibited a functional impairment in their response to endurance exercise training, as reflected by reduced maximal running capacity (20%) and reduced time to fatigue during prolonged submaximal exercise (15%). The reduction in exercise performance was not accompanied by alterations in carbohydrate and fatty acid metabolism during submaximal exercise. Similarly, mitochondrial capacity (mtDNA, respiratory complex proteins, citrate synthase activity) and mitochondrial function (oxygen consumption rate in muscle fiber bundles) were not different between lox/lox and Plin5(MKO) mice. Thus, PLIN5 is dispensable for normal substrate metabolism during exercise and is not required to promote mitochondrial biogenesis or enhance the cellular adaptations to endurance exercise training. PMID:27189934

  20. Urban focus in climate change adaptation and risk reduction

    Wamsler, Christine

    2014-01-01

    Urban communities will face increased risks, such as floods, landslides, heat stress and fires and water scarcity, as a consequence of climate change. The latest IPCC report (AR5) has for the first time devoted a whole chapter to urban areas. The assessment stresses the need to tackle urban risk through more effective adaptation planning.

  1. Nation-building policies in Timor-Leste: Disaster Risk Reduction and Climate Change Adaptation

    Mercer, Jessica; Kelman, Ilan; do Rosario, F.; de Deus de Jesus Lima, A.; A. da Silva; Beloff, A. M.; McClean, A.

    2014-01-01

    Few studies have explored the relationships between nation-building, disaster risk reduction and climate change adaptation. Focusing on small island developing states, this paper examines nation-building in Timor-Leste, a small island developing state that recently achieved independence. Nation-building in Timor-Leste is explored in the context of disaster risk reduction, which necessarily includes climate change adaptation. The study presents a synopsis of Timor-Leste's history and its natio...

  2. AMPKα in Exercise-Induced Substrate Metabolism and Exercise Training-Induced Metabolic and Mitochondrial Adaptations

    Fentz, Joachim

    A bout of exercise potently stimulates skeletal muscle energy metabolism. The ATP turnover may rise up to0 ~100 fold compared to the resting state and this presents a substantial stress on skeletal muscle ATP regeneration. To prepare for future events of metabolic stress, the muscle increases its...

  3. An Adaptive Design Methodology for Reduction of Product Development Risk

    Pakala, Hara Gopal Mani; Kvsvn, Dr Raju; Khan, Dr Ibrahim; 10.5121/ijasuc.2011.2303

    2011-01-01

    Embedded systems interaction with environment inherently complicates understanding of requirements and their correct implementation. However, product uncertainty is highest during early stages of development. Design verification is an essential step in the development of any system, especially for Embedded System. This paper introduces a novel adaptive design methodology, which incorporates step-wise prototyping and verification. With each adaptive step product-realization level is enhanced while decreasing the level of product uncertainty, thereby reducing the overall costs. The back-bone of this frame-work is the development of Domain Specific Operational (DOP) Model and the associated Verification Instrumentation for Test and Evaluation, developed based on the DOP model. Together they generate functionally valid test-sequence for carrying out prototype evaluation. With the help of a case study 'Multimode Detection Subsystem' the application of this method is sketched. The design methodologies can be compar...

  4. Adaptive noise reduction for fiber optic gyroscopes in borehole applications

    Yan, Tingyang; Zhang, Chunxi; Gao, Shuang; Ma, Zongfeng

    2006-11-01

    Fiber Optic Gyroscopes (FOGs) have been investigated and proposed as alternative sensors to magnetometers in borehole surveying applications due to their compactness, ruggedness, low cost and high environmental insensitivity. However, FOGs are subject to high measurement noise from various sources, which deteriorates the performance and quality of FOGs, thus the overall system accuracy is limited. To improve the accuracy of the surveying system, adaptive filtering techniques are utilized to reduce the noise level at the output of the FOG. A Forward Linear Prediction (FLP) filter based on Normalized Least-Mean-Square (NLMS) adaptive algorithm was designed and evaluated using kinematic data. Results show that the FLP filter can suppress the FOG noise to a certain degree and a satisfactory signal-to-noise ratio improvement can be achieved using this method.

  5. An Adaptive Design Methodology for Reduction of Product Development Risk

    Hara Gopal Mani Pakala

    2011-09-01

    Full Text Available Embedded systems interaction with environment inher ently complicates understanding of requirements and their correct implementation. However, product unce rtainty is highest during early stages of developme nt. Design verification is an essential step in the dev elopment of any system, especially for Embedded Sys tem. This paper introduces a novel adaptive design metho dology, which incorporates step-wise prototyping an d verification. With each adaptive step product-reali zation level is enhanced while decreasing the level of product uncertainty, thereby reducing the overall c osts. The back-bone of this frame-work is the development of Domain Specific Operational (DOP Mo del and the associated Verification Instrumentation for Test and Evaluation, developed based on the DOP model. Together they generate functionally valid test-sequence for carrying out p rototype evaluation. With the help of a case study ‘Multi- mode Detection Subsystem’ the application of this m ethod is sketched. The design methodologies can be compared by defining and computing a generic perfor mance criterion like Average design-cycle Risk. For the case study, by computing Average design-cycle Risk, it is shown that the adaptive me thod reduces the product development risk for a small increase in th e total design cycle time

  6. Boots for Achilles: progesterone's reduction of cholesterol is a second-order adaptation.

    Amir, Dorsa; Fessler, Daniel M T

    2013-06-01

    Progesterone and cholesterol are both vital to pregnancy. Among other functions, progesterone downregulates inflammatory responses, allowing for maternal immune tolerance of the fetal allograft. Cholesterol a key component of cell membranes, is important in intracellular transport, cell signaling, nerve conduction, and metabolism Despite the importance of each substance in pregnancy, one exercises an antagonistic effect on the other, as periods of peak progesterone correspond with reductions in cholesterol availability, a consequence of progesterone's negative effects on cholesterol biosynthesis. This arrangement is understandable in light of the threat posed by pathogens early in pregnancy. Progesterone-induced immunomodulation entails increased vulnerability to infection, an acute problem in the first trimester, when fetal development is highly susceptible to insult. Many pathogens rely on cholesterol for cell entry, egress, and replication. Progesterone's antagonistic effects on cholesterol thus partially compensate for the costs entailed by progesterone-induced immunomodulation. Among pathogens to which the host's vulnerability is increased by progesterone's effects, approximately 90% utilize cholesterol, and this is notably true of pathogens that pose a risk during pregnancy. In addition to having a number of possible clinical applications, our approach highlights the potential importance of second-order adaptations, themselves a consequence of the lack of teleology in evolutionary processes. PMID:23909226

  7. Carbohydrate oxidation coupled to Fe(III) reduction, a novel form of anaerobic metabolism.

    Coates, J D; Councell, T; Ellis, D J; Lovley, D R

    1998-12-01

    An isolate, designated GC-29, that could incompletely oxidize glucose to acetate and carbon dioxide with Fe(III) serving as the electron acceptor was recovered from freshwater sediments of the Potomac River, Maryland. This metabolism yielded energy to support cell growth. Strain GC-29 is a facultatively anaerobic, gram-negative motile rod which, in addition to glucose, also used sucrose, lactate, pyruvate, yeast extract, casamino acids or H2 as alternative electron donors for Fe(III) reduction. Stain GC-29 could reduce NO3(-), Mn(IV), U(VI), fumarate, malate, S2O3(2-), and colloidal S0 as well as the humics analog, 2,6-anthraquinone disulfonate. Analysis of the almost complete 16S rRNA sequence indicated that strain GC-29 belongs in the Shewanella genus in the epsilon subdivision of the Proteobacteria. The name Shewanella saccharophilia is proposed. Shewanella saccharophilia differs from previously described fermentative microorganisms that metabolize glucose with the reduction of Fe(III) because it transfers significantly more electron equivalents to Fe(III); acetate and carbon dioxide are the only products of glucose metabolism; energy is conserved from Fe(III) reduction; and glucose is not metabolized in the absence of Fe(III). The metabolism of organisms like S. saccharophilia may account for the fact that glucose is metabolized primarily to acetate and carbon dioxide in a variety of sediments in which Fe(III) reduction is the terminal electron accepting process. PMID:16887653

  8. Metabolic adaptation of skeletal muscles to gravitational unloading

    Ohira, Y.; Yasui, W.; Kariya, F.; Wakatsuki, T.; Nakamura, K.; Asakura, T.; Edgerton, V. R.

    Responses of high-energy phosphates and metabolic properties to hindlimb suspension were studied in adult rats. The relative content of phosphocreatine (PCr) in the calf muscles was significantly higher in rats suspended for 10 days than in age-matched cage controls. The Pi/PCr ratio, where Pi is inorganic phosphate, in suspended muscles was less than controls. The absolute weights of soleus and medial gastrocnemius (MG) were approximately 40% less than controls. Although the % fiber distribution in MG was unchanged, the % slow fibers decreased and the % fibers which were classified as both slow and fast was increased in soleus. The activities (per unit weight or protein) of succinate dehydrogenase and lactate dehydrogenase in soleus were unchanged but those of cytochrome oxidase, β-hydroxyacyl CoA dehydrogenase, and citrate synthase were decreased following unloading. None of these enzyme activities in MG changed. However, the total levels of all enzymes in whole muscles decreased by suspension. It is suggested that shift of slow muscle toward fast type by unloading is associated with a decrease in mitochondrial biogenesis. Further, gravitational unloading affected the levels of muscle proteins differently even in the same mitochondrial enzymes. Unloading-related atrophy is prominent in red muscle or slow-twitch fiber 1, 2. Such atrophy is accompanied by a shift of contractile properties toward fast-twitch type 2-9. Further, inhibition of mitochondrial metabolism in these muscles is also reported by some studies 10-14 suggesting a lowered mitochondrial biogenesis, although results from some studies do not necessarily agree 1, 7, 15. However, the precise mechanism responsible for such alterations of muscle properties in response to gravitational unloading is unclear. On the contrary, mitochondrial biogenesis, suggested by mitochondrial enzyme activities and/or mass, is stimulated in muscles with depleted high-energy phosphates by cold exposure 16 and/or by feeding

  9. Cold adaptation mechanisms in the ghost moth Hepialus xiaojinensis: Metabolic regulation and thermal compensation.

    Zhu, Wei; Zhang, Huan; Li, Xuan; Meng, Qian; Shu, Ruihao; Wang, Menglong; Zhou, Guiling; Wang, Hongtuo; Miao, Lin; Zhang, Jihong; Qin, Qilian

    2016-02-01

    Ghost moths (Lepidoptera: Hepialidae) are cold-adapted stenothermal species inhabiting alpine meadows on the Tibetan Plateau. They have an optimal developmental temperature of 12-16°C but can maintain feeding and growth at 0°C. Their survival strategies have received little attention, but these insects are a promising model for environmental adaptation. Here, biochemical adaptations and energy metabolism in response to cold were investigated in larvae of the ghost moth Hepialus xiaojinensis. Metabolic rate and respiratory quotient decreased dramatically with decreasing temperature (15-4°C), suggesting that the energy metabolism of ghost moths, especially glycometabolism, was sensitive to cold. However, the metabolic rate at 4°C increased with the duration of cold exposure, indicating thermal compensation to sustain energy budgets under cold conditions. Underlying regulation strategies were studied by analyzing metabolic differences between cold-acclimated (4°C for 48h) and control larvae (15°C). In cold-acclimated larvae, the energy generating pathways of carbohydrates, instead of the overall consumption of carbohydrates, was compensated in the fat body by improving the transcription of related enzymes. The mobilization of lipids was also promoted, with higher diacylglycerol, monoacylglycerol and free fatty acid content in hemolymph. These results indicated that cold acclimation induced a reorganization on metabolic structure to prioritise energy metabolism. Within the aerobic process, flux throughout the tricarboxylic acid (TCA) cycle was encouraged in the fat body, and the activity of α-ketoglutarate dehydrogenase was the likely compensation target. Increased mitochondrial cristae density was observed in the midgut of cold-acclimated larvae. The thermal compensation strategies in this ghost moth span the entire process of energy metabolism, including degration of metabolic substrate, TCA cycle and oxidative phosphorylation, and from an energy budget

  10. Perceptual adaptation to segmental and syllabic reductions in continuous spoken Dutch

    Poellmann, K.; Bosker, H.R.; McQueen, J.M.; Mitterer, H.A.

    2014-01-01

    This study investigates if and how listeners adapt to reductions in casual continuous speech. In a perceptual-learning variant of the visual-world paradigm, two groups of Dutch participants were exposed to either segmental (/b/ -> [upsilon] or syllabic (ver- -> [f:]) reductions in spoken Dutch

  11. Peripheral reduction of FGFR4 with antisense oligonucleotides increases metabolic rate and lowers adiposity in diet-induced obese mice.

    Xing Xian Yu

    Full Text Available Obesity is a primary risk factor for multiple metabolic disorders. Many drugs for the treatment of obesity, which mainly act through CNS as appetite suppressants, have failed during development or been removed from the market due to unacceptable adverse effects. Thus, there are very few efficacious drugs available and remains a great unmet medical need for anti-obesity drugs that increase energy expenditure by acting on peripheral tissues without severe side effects. Here, we report a novel approach involving antisense inhibition of fibroblast growth factor receptor 4 (FGFR4 in peripheral tissues. Treatment of diet-induce obese (DIO mice with FGFR4 antisense oligonucleotides (ASO specifically reduced liver FGFR4 expression that not only resulted in decrease in body weight (BW and adiposity in free-feeding conditions, but also lowered BW and adiposity under caloric restriction. In addition, combination treatment with FGFR4 ASO and rimonabant showed additive reduction in BW and adiposity. FGFR4 ASO treatment increased basal metabolic rate during free-feeding conditions and, more importantly, prevented adaptive decreases of metabolic rate induced by caloric restriction. The treatment increased fatty acid oxidation while decreased lipogenesis in both liver and fat. Mechanistic studies indicated that anti-obesity effect of FGFR4 ASO was mediated at least in part through an induction of plasma FGF15 level resulted from reduction of hepatic FGFR4 expression. The anti-obesity effect was accompanied by improvement in plasma glycemia, whole body insulin sensitivity, plasma lipid levels and liver steatosis. Therefore, FGFR4 could be a potential novel target and antisense reduction of hepatic FGFR4 expression could be an efficacious therapy as an adjunct to diet restriction or to an appetite suppressant for the treatment of obesity and related metabolic disorders.

  12. Reduction of Radiographic Quantum Noise Using Adaptive Weighted Median Filter

    Images are easily corrupted by noise during the data transmission, data capture and data processing. A technical method of noise analyzing and adaptive filtering for reducing of quantum noise in radiography is presented. By adjusting the characteristics of the filter according to local statistics around each pixel of the image as moving windowing, it is possible to suppress noise sufficiently while preserve edge and other significant information required in reading. We have proposed adaptive weighted median(AWM) filters based on local statistics. We show two ways of realizing the AWM filters. One is a simple type of AWM filter, whose weights are given by a simple non-linear function of three local characteristics. The other is the AWM filter which is constructed by homogeneous factor(HF). Homogeneous factor(HF) from the quantum noise models that enables the filter to recognize the local structures of the image is introduced, and an algorithm for determining the HF fitted to the detection systems with various inner statistical properties is proposed. We show by the experimented that the performances of proposed method is superior to these of other filters and models in preserving small details and suppressing the noise at homogeneous region. The proposed algorithms were implemented by visual C++ language on a IBM-PC Pentium 550 for testing purposes, the effects and results of the noise filtering were proposed by comparing with images of the other existing filtering methods

  13. FoxO3A promotes metabolic adaptation to hypoxia by antagonizing Myc function

    Jensen, Kim Steen; Binderup, Tina; Jensen, Klaus Thorleif;

    2011-01-01

    Exposure of metazoan organisms to hypoxia engages a metabolic switch orchestrated by the hypoxia-inducible factor 1 (HIF-1). HIF-1 mediates induction of glycolysis and active repression of mitochondrial respiration that reduces oxygen consumption and inhibits the production of potentially harmful...... tumour tissue in vivo and that FoxO3A short-hairpin RNA (shRNA)-expressing xenograft tumours are decreased in size and metabolically changed. Our findings define a novel mechanism by which FoxO3A promotes metabolic adaptation and stress resistance in hypoxia....

  14. Structured estimation - Sample size reduction for adaptive pattern classification

    Morgera, S.; Cooper, D. B.

    1977-01-01

    The Gaussian two-category classification problem with known category mean value vectors and identical but unknown category covariance matrices is considered. The weight vector depends on the unknown common covariance matrix, so the procedure is to estimate the covariance matrix in order to obtain an estimate of the optimum weight vector. The measure of performance for the adapted classifier is the output signal-to-interference noise ratio (SIR). A simple approximation for the expected SIR is gained by using the general sample covariance matrix estimator; this performance is both signal and true covariance matrix independent. An approximation is also found for the expected SIR obtained by using a Toeplitz form covariance matrix estimator; this performance is found to be dependent on both the signal and the true covariance matrix.

  15. Locomotor Adaptation Improves Balance Control, Multitasking Ability and Reduces the Metabolic Cost of Postural Instability

    Bloomberg, J. J.; Peters, B. T.; Mulavara, A. P.; Brady, R. A.; Batson, C. D.; Miller, C. A.; Ploutz-Snyder, R. J.; Guined, J. R.; Buxton, R. E.; Cohen, H. S.

    2011-01-01

    During exploration-class missions, sensorimotor disturbances may lead to disruption in the ability to ambulate and perform functional tasks during the initial introduction to a novel gravitational environment following a landing on a planetary surface. The overall goal of our current project is to develop a sensorimotor adaptability training program to facilitate rapid adaptation to these environments. We have developed a unique training system comprised of a treadmill placed on a motion-base facing a virtual visual scene. It provides an unstable walking surface combined with incongruent visual flow designed to enhance sensorimotor adaptability. Greater metabolic cost incurred during balance instability means more physical work is required during adaptation to new environments possibly affecting crewmembers? ability to perform mission critical tasks during early surface operations on planetary expeditions. The goal of this study was to characterize adaptation to a discordant sensory challenge across a number of performance modalities including locomotor stability, multi-tasking ability and metabolic cost. METHODS: Subjects (n=15) walked (4.0 km/h) on a treadmill for an 8 -minute baseline walking period followed by 20-minutes of walking (4.0 km/h) with support surface motion (0.3 Hz, sinusoidal lateral motion, peak amplitude 25.4 cm) provided by the treadmill/motion-base system. Stride frequency and auditory reaction time were collected as measures of locomotor stability and multi-tasking ability, respectively. Metabolic data (VO2) were collected via a portable metabolic gas analysis system. RESULTS: At the onset of lateral support surface motion, subj ects walking on our treadmill showed an increase in stride frequency and auditory reaction time indicating initial balance and multi-tasking disturbances. During the 20-minute adaptation period, balance control and multi-tasking performance improved. Similarly, throughout the 20-minute adaptation period, VO2 gradually

  16. Energy metabolism of overweight women before, during and after weight reduction assessed by indirect calorimetry.

    Groot, de C.P.G.M.

    1988-01-01

    Previous studies had suggested that periods of low energy intake evoke compensatory adaptations in energy metabolism, which retard weight loss, and promote weight regain when energy intake returns to normal. The aim of this thesis was to investigate whether a slimming (low-energy) diet based on alte

  17. Adaptative diversity of calcium metabolism in gammarus fossarum populations

    Analysis of Gammarus fossarum populations from mountain torrents in the Grenoble region reveals some morphological and eco physiological diversity which appears to be related to the calcium concentration of the water after both field and laboratory experimentation. Animals from waters with a high calcium concentration (located in Chartreuse and Vercors) show larger size and a longer molt cycle than those from low calcium concentrated waters (located in Belledonne); their calcium balance during the molt cycle is different. Translocation experiments confirm these differences: a significant increase of the duration of the molt cycle is observed in animals translocated to lower calcium concentrated waters and vice-versa whereas no significant difference is observed between controls and animals translocated within comparably calcium concentrated waters. The causes of such an adaptative diversity between Gammarus fossarum populations will be researched at the genetic level, namely through mitochondrial DNA investigations. (author). 25 refs., 2 tabs., 2 figs

  18. Recovery of Phenotypes Obtained by Adaptive Evolution through Inverse Metabolic Engineering

    Hong, Kuk-Ki; Nielsen, Jens

    2012-01-01

    In a previous study, system level analysis of adaptively evolved yeast mutants showing improved galactose utilization revealed relevant mutations. The governing mutations were suggested to be in the Ras/PKA signaling pathway and ergosterol metabolism. Here, site-directed mutants having one of the...

  19. Adaptive dimension reduction for clustering high dimensional data

    Ding, Chris; He, Xiaofeng; Zha, Hongyuan; Simon, Horst

    2002-10-01

    It is well-known that for high dimensional data clustering, standard algorithms such as EM and the K-means are often trapped in local minimum. many initialization methods were proposed to tackle this problem, but with only limited success. In this paper they propose a new approach to resolve this problem by repeated dimension reductions such that K-means or EM are performed only in very low dimensions. Cluster membership is utilized as a bridge between the reduced dimensional sub-space and the original space, providing flexibility and ease of implementation. Clustering analysis performed on highly overlapped Gaussians, DNA gene expression profiles and internet newsgroups demonstrate the effectiveness of the proposed algorithm.

  20. Metabolic Disorders in the Transition Period Indicate that the Dairy Cows’ Ability to Adapt is Overstressed

    Sundrum, Albert

    2015-01-01

    Simple Summary Metabolic disorders are a key problem in the transition period of dairy cows and often appear before the onset of further health problems. Problems derive from difficulties animals have to adapt to large variations and disturbances occurring both outside and inside the organism. A lack of success in solving these issues may be due to predominant approaches in farm management and agricultural science, dealing with such disorders as merely negative side effects. Instead, a successful adaptation of animals to their living conditions should be seen as an important end in itself. Both farm management and agricultural sciences should support animals in their ability to cope with nutritional and metabolic challenges by employing a functional and result-driven approach. Abstract Metabolic disorders are a key problem in the transition period of dairy cows and often appear before the onset of further health problems. They mainly derive from difficulties the animals have in adapting to changes and disturbances occurring both outside and inside the organisms and due to varying gaps between nutrient supply and demand. Adaptation is a functional and target-oriented process involving the whole organism and thus cannot be narrowed down to single factors. Most problems which challenge the organisms can be solved in a number of different ways. To understand the mechanisms of adaptation, the interconnectedness of variables and the nutrient flow within a metabolic network need to be considered. Metabolic disorders indicate an overstressed ability to balance input, partitioning and output variables. Dairy cows will more easily succeed in adapting and in avoiding dysfunctional processes in the transition period when the gap between nutrient and energy demands and their supply is restricted. Dairy farms vary widely in relation to the living conditions of the animals. The complexity of nutritional and metabolic processes and their large variations on various scales

  1. Metabolic adaptation in transplastomic plants massively accumulating recombinant proteins.

    Julia Bally

    Full Text Available BACKGROUND: Recombinant chloroplasts are endowed with an astonishing capacity to accumulate foreign proteins. However, knowledge about the impact on resident proteins of such high levels of recombinant protein accumulation is lacking. METHODOLOGY/PRINCIPAL FINDINGS: Here we used proteomics to characterize tobacco (Nicotiana tabacum plastid transformants massively accumulating a p-hydroxyphenyl pyruvate dioxygenase (HPPD or a green fluorescent protein (GFP. While under the conditions used no obvious modifications in plant phenotype could be observed, these proteins accumulated to even higher levels than ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco, the most abundant protein on the planet. This accumulation occurred at the expense of a limited number of leaf proteins including Rubisco. In particular, enzymes involved in CO(2 metabolism such as nuclear-encoded plastidial Calvin cycle enzymes and mitochondrial glycine decarboxylase were found to adjust their accumulation level to these novel physiological conditions. CONCLUSIONS/SIGNIFICANCE: The results document how protein synthetic capacity is limited in plant cells. They may provide new avenues to evaluate possible bottlenecks in recombinant protein technology and to maintain plant fitness in future studies aiming at producing recombinant proteins of interest through chloroplast transformation.

  2. On the accessibility of adaptive phenotypes of a bacterial metabolic network.

    Wilfred Ndifon

    2009-08-01

    Full Text Available The mechanisms by which adaptive phenotypes spread within an evolving population after their emergence are understood fairly well. Much less is known about the factors that influence the evolutionary accessibility of such phenotypes, a pre-requisite for their emergence in a population. Here, we investigate the influence of environmental quality on the accessibility of adaptive phenotypes of Escherichia coli's central metabolic network. We used an established flux-balance model of metabolism as the basis for a genotype-phenotype map (GPM. We quantified the effects of seven qualitatively different environments (corresponding to both carbohydrate and gluconeogenic metabolic substrates on the structure of this GPM. We found that the GPM has a more rugged structure in qualitatively poorer environments, suggesting that adaptive phenotypes could be intrinsically less accessible in such environments. Nevertheless, on average approximately 74% of the genotype can be altered by neutral drift, in the environment where the GPM is most rugged; this could allow evolving populations to circumvent such ruggedness. Furthermore, we found that the normalized mutual information (NMI of genotype differences relative to phenotype differences, which measures the GPM's capacity to transmit information about phenotype differences, is positively correlated with (simulation-based estimates of the accessibility of adaptive phenotypes in different environments. These results are consistent with the predictions of a simple analytic theory that makes explicit the relationship between the NMI and the speed of adaptation. The results suggest an intuitive information-theoretic principle for evolutionary adaptation; adaptation could be faster in environments where the GPM has a greater capacity to transmit information about phenotype differences. More generally, our results provide insight into fundamental environment-specific differences in the accessibility of adaptive

  3. Metabolic Disorders in the Transition Period Indicate that the Dairy Cows’ Ability to Adapt is Overstressed

    Albert Sundrum

    2015-10-01

    Full Text Available Metabolic disorders are a key problem in the transition period of dairy cows and often appear before the onset of further health problems. They mainly derive from difficulties the animals have in adapting to changes and disturbances occurring both outside and inside the organisms and due to varying gaps between nutrient supply and demand. Adaptation is a functional and target-oriented process involving the whole organism and thus cannot be narrowed down to single factors. Most problems which challenge the organisms can be solved in a number of different ways. To understand the mechanisms of adaptation, the interconnectedness of variables and the nutrient flow within a metabolic network need to be considered. Metabolic disorders indicate an overstressed ability to balance input, partitioning and output variables. Dairy cows will more easily succeed in adapting and in avoiding dysfunctional processes in the transition period when the gap between nutrient and energy demands and their supply is restricted. Dairy farms vary widely in relation to the living conditions of the animals. The complexity of nutritional and metabolic processes Animals 2015, 5 979 and their large variations on various scales contradict any attempts to predict the outcome of animals’ adaptation in a farm specific situation. Any attempts to reduce the prevalence of metabolic disorders and associated production diseases should rely on continuous and comprehensive monitoring with appropriate indicators on the farm level. Furthermore, low levels of disorders and diseases should be seen as a further significant goal which carries weight in addition to productivity goals. In the long run, low disease levels can only be expected when farmers realize that they can gain a competitive advantage over competitors with higher levels of disease.

  4. A non-traditional model of the metabolic syndrome: the adaptive significance of insulin resistance in fasting-adapted seals

    Dorian S Houser

    2013-11-01

    Full Text Available Insulin resistance in modern society is perceived as a pathological consequence of excess energy consumption and reduced physical activity. Its presence in relation to the development of cardiovascular risk factors has been termed the metabolic syndrome, which produces increased mortality and morbidity and which is rapidly increasing in human populations. Ironically, insulin resistance likely evolved to assist animals during food shortages by increasing the availability of endogenous lipid for catabolism while protecting protein from use in gluconeogenesis and eventual oxidation. Some species that incorporate fasting as a predictable component of their life history demonstrate physiological traits similar to the metabolic syndrome during prolonged fasts. One such species is the northern elephant seal (Mirounga angustirostris, which fasts from food and water for periods of up to three months. During this time, ~90% of the seals metabolic demands are met through fat oxidation and circulating non-esterified fatty acids are high (0.7-3.2 mM. All life history stages of elephant seal studied to date demonstrate insulin resistance and fasting hyperglycemia as well as variations in hormones and adipocytokines that reflect the metabolic syndrome to some degree. Elephant seals demonstrate some intriguing adaptations with the potential for medical advancement; for example, ketosis is negligible despite significant and prolonged fatty acid oxidation and investigation of this feature might provide insight into the treatment of diabetic ketoacidosis. The parallels to the metabolic syndrome are likely reflected to varying degrees in other marine mammals, most of which evolved on diets high in lipid and protein content but essentially devoid of carbohydrate. Utilization of these natural models of insulin resistance may further our understanding of the pathophysiology of the metabolic syndrome in humans and better assist the development of preventative measures

  5. Radar Range Sidelobe Reduction Using Adaptive Pulse Compression Technique

    Li, Lihua; Coon, Michael; McLinden, Matthew

    2013-01-01

    Pulse compression has been widely used in radars so that low-power, long RF pulses can be transmitted, rather than a highpower short pulse. Pulse compression radars offer a number of advantages over high-power short pulsed radars, such as no need of high-power RF circuitry, no need of high-voltage electronics, compact size and light weight, better range resolution, and better reliability. However, range sidelobe associated with pulse compression has prevented the use of this technique on spaceborne radars since surface returns detected by range sidelobes may mask the returns from a nearby weak cloud or precipitation particles. Research on adaptive pulse compression was carried out utilizing a field-programmable gate array (FPGA) waveform generation board and a radar transceiver simulator. The results have shown significant improvements in pulse compression sidelobe performance. Microwave and millimeter-wave radars present many technological challenges for Earth and planetary science applications. The traditional tube-based radars use high-voltage power supply/modulators and high-power RF transmitters; therefore, these radars usually have large size, heavy weight, and reliability issues for space and airborne platforms. Pulse compression technology has provided a path toward meeting many of these radar challenges. Recent advances in digital waveform generation, digital receivers, and solid-state power amplifiers have opened a new era for applying pulse compression to the development of compact and high-performance airborne and spaceborne remote sensing radars. The primary objective of this innovative effort is to develop and test a new pulse compression technique to achieve ultrarange sidelobes so that this technique can be applied to spaceborne, airborne, and ground-based remote sensing radars to meet future science requirements. By using digital waveform generation, digital receiver, and solid-state power amplifier technologies, this improved pulse compression

  6. CydDC-mediated reductant export in Escherichia coli controls the transcriptional wiring of energy metabolism and combats nitrosative stress.

    Holyoake, Louise V; Hunt, Stuart; Sanguinetti, Guido; Cook, Gregory M; Howard, Mark J; Rowe, Michelle L; Poole, Robert K; Shepherd, Mark

    2016-03-15

    The glutathione/cysteine exporter CydDC maintains redox balance in Escherichia coli. A cydD mutant strain was used to probe the influence of CydDC upon reduced thiol export, gene expression, metabolic perturbations, intracellular pH homoeostasis and tolerance to nitric oxide (NO). Loss of CydDC was found to decrease extracytoplasmic thiol levels, whereas overexpression diminished the cytoplasmic thiol content. Transcriptomic analysis revealed a dramatic up-regulation of protein chaperones, protein degradation (via phenylpropionate/phenylacetate catabolism), β-oxidation of fatty acids and genes involved in nitrate/nitrite reduction. (1)H NMR metabolomics revealed elevated methionine and betaine and diminished acetate and NAD(+) in cydD cells, which was consistent with the transcriptomics-based metabolic model. The growth rate and ΔpH, however, were unaffected, although the cydD strain did exhibit sensitivity to the NO-releasing compound NOC-12. These observations are consistent with the hypothesis that the loss of CydDC-mediated reductant export promotes protein misfolding, adaptations to energy metabolism and sensitivity to NO. The addition of both glutathione and cysteine to the medium was found to complement the loss of bd-type cytochrome synthesis in a cydD strain (a key component of the pleiotropic cydDC phenotype), providing the first direct evidence that CydDC substrates are able to restore the correct assembly of this respiratory oxidase. These data provide an insight into the metabolic flexibility of E. coli, highlight the importance of bacterial redox homoeostasis during nitrosative stress, and report for the first time the ability of periplasmic low molecular weight thiols to restore haem incorporation into a cytochrome complex. PMID:26699904

  7. Role of AMPK in skeletal muscle metabolic regulation and adaptation in relation to exercise

    Jørgensen, Sebastian Beck; Richter, Erik; Wojtaszewski, Jørgen

    2006-01-01

    The 5'-AMP-activated protein kinase (AMPK) is a potent regulator of skeletal muscle metabolism and gene expression. AMPK is activated both in response to in vivo exercise and ex vivo contraction. AMPK is therefore believed to be an important signalling molecule in regulating muscle metabolism...... furthermore discuss the possible role of AMPK as a master switch in skeletal muscle metabolism with the main focus on AMPK in metabolic regulation during muscle work. Finally, AMPK has a well established role in regulating expression of genes encoding various enzymes in muscle, and this issue is discussed in...... during exercise as well as in adaptation of skeletal muscle to exercise training. The first part of this review is focused on different mechanisms regulating AMPK activity during muscle work such as alterations in nucleotide concentrations, availability of energy substrates and upstream AMPK kinases. We...

  8. Identification of a Perchlorate Reduction Genomic Island with Novel Regulatory and Metabolic Genes ▿

    Melnyk, Ryan A.; Engelbrektson, Anna; Clark, Iain C.; Carlson, Hans K.; Byrne-Bailey, Kathy; Coates, John D.

    2011-01-01

    A comparative analysis of the genomes of four dissimilatory (per)chlorate-reducing bacteria has revealed a genomic island associated with perchlorate reduction. In addition to the characterized metabolic genes for perchlorate reductase and chlorite dismutase, the island contains multiple conserved uncharacterized genes possibly involved in electron transport and regulation.

  9. Identification of a perchlorate reduction genomic island with novel regulatory and metabolic genes.

    Melnyk, Ryan A; Engelbrektson, Anna; Clark, Iain C; Carlson, Hans K; Byrne-Bailey, Kathy; Coates, John D

    2011-10-01

    A comparative analysis of the genomes of four dissimilatory (per)chlorate-reducing bacteria has revealed a genomic island associated with perchlorate reduction. In addition to the characterized metabolic genes for perchlorate reductase and chlorite dismutase, the island contains multiple conserved uncharacterized genes possibly involved in electron transport and regulation. PMID:21856823

  10. Parallel structures for disaster risk reduction and climate change adaptation in Southern Africa

    Per Becker

    2013-01-01

    Full Text Available During the last decade, the interest of the international community in the concepts of disaster risk reduction and climate change adaptation has been growing immensely. Even though an increasing number of scholars seem to view these concepts as two sides of the same coin (at least when not considering the potentially positive effects of climate change, in practice the two concepts have developed in parallel rather than in an integrated manner when it comes to policy, rhetoric and funding opportunities amongst international organisations and donors. This study investigates the extent of the creation of parallel structures for disaster risk reduction and climate change adaptation in the Southern African Development Community (SADC region. The chosen methodology for the study is a comparative case study and the data are collected through focus groups and content analysis of documentary sources, as well as interviews with key informants. The results indicate that parallel structures for disaster risk reduction and climate change adaptation have been established in all but one of the studied countries. The qualitative interviews performed in some of the countries indicate that stakeholders in disaster risk reduction view this duplication of structures as unfortunate, inefficient and a fertile setup for conflict over resources for the implementation of similar activities. Additional research is called for in order to study the concrete effects of having these parallel structures as a foundation for advocacy for more efficient future disaster risk reduction and climate change adaptation.

  11. Coregulation of host-adapted metabolism and virulence by pathogenic yersiniae

    Ann Kathrin eHeroven

    2014-10-01

    Full Text Available Deciphering the principles how pathogenic bacteria adapt their metabolism to a specific host microenvironment is critical for understanding bacterial pathogenesis. The enteric pathogenic Yersinia species Y. pseudotuberculosis and Y. enterocolitica and the causative agent of plague, Y. pestis, are able to survive in a large variety of environmental reservoirs (e.g. soil, plants, insects as well as warm-blooded animals (e.g. rodents, pigs, humans with a particular preference for lymphatic tissues. In order to manage rapidly changing environmental conditions and inter-bacterial competition, Yersinia senses the nutritional composition during the course of an infection by special molecular devices, integrates this information and adapts its metabolism accordingly. In addition, nutrient availability has an impact on expression of virulence genes in response to C-sources, demonstrating a tight link between the pathogenicity of yersiniae and utilization of nutrients. Recent studies revealed that global regulatory factors such as the cAMP receptor protein (Crp and the carbon storage regulator (Csr system are part of a large network of transcriptional and posttranscriptional control strategies adjusting metabolic changes and virulence in response to temperature, ion and nutrient availability. Gained knowledge about the specific metabolic requirements and the correlation between metabolic and virulence gene expression that enable efficient host colonization led to the identification of new potential antimicrobial targets.

  12. Coregulation of host-adapted metabolism and virulence by pathogenic yersiniae.

    Heroven, Ann Kathrin; Dersch, Petra

    2014-01-01

    Deciphering the principles how pathogenic bacteria adapt their metabolism to a specific host microenvironment is critical for understanding bacterial pathogenesis. The enteric pathogenic Yersinia species Yersinia pseudotuberculosis and Yersinia enterocolitica and the causative agent of plague, Yersinia pestis, are able to survive in a large variety of environmental reservoirs (e.g., soil, plants, insects) as well as warm-blooded animals (e.g., rodents, pigs, humans) with a particular preference for lymphatic tissues. In order to manage rapidly changing environmental conditions and interbacterial competition, Yersinia senses the nutritional composition during the course of an infection by special molecular devices, integrates this information and adapts its metabolism accordingly. In addition, nutrient availability has an impact on expression of virulence genes in response to C-sources, demonstrating a tight link between the pathogenicity of yersiniae and utilization of nutrients. Recent studies revealed that global regulatory factors such as the cAMP receptor protein (Crp) and the carbon storage regulator (Csr) system are part of a large network of transcriptional and posttranscriptional control strategies adjusting metabolic changes and virulence in response to temperature, ion and nutrient availability. Gained knowledge about the specific metabolic requirements and the correlation between metabolic and virulence gene expression that enable efficient host colonization led to the identification of new potential antimicrobial targets. PMID:25368845

  13. The evolution of control and distribution of adaptive mutations in a metabolic pathway.

    Wright, Kevin M; Rausher, Mark D

    2010-02-01

    In an attempt to understand whether it should be expected that some genes tend to be used disproportionately often by natural selection, we investigated two related phenomena: the evolution of flux control among enzymes in a metabolic pathway and properties of adaptive substitutions in pathway enzymes. These two phenomena are related by the principle that adaptive substitutions should occur more frequently in enzymes with greater flux control. Predicting which enzymes will be preferentially involved in adaptive evolution thus requires an evolutionary theory of flux control. We investigated the evolution of enzyme control in metabolic pathways with two models of enzyme kinetics: metabolic control theory (MCT) and Michaelis-Menten saturation kinetics (SK). Our models generate two main predictions for pathways in which reactions are moderately to highly irreversible: (1) flux control will evolve to be highly unequal among enzymes in a pathway and (2) upstream enzymes evolve a greater control coefficient then those downstream. This results in upstream enzymes fixing the majority of beneficial mutations during adaptive evolution. Once the population has reached high fitness, the trend is reversed, with the majority of neutral/slightly deleterious mutations occurring in downstream enzymes. These patterns are the result of three factors (the first of these is unique to the MCT simulations while the other two seem to be general properties of the metabolic pathways): (1) the majority of randomly selected, starting combinations of enzyme kinetic rates generate pathways that possess greater control for the upstream enzymes compared to downstream enzymes; (2) selection against large pools of intermediate substrates tends to prevent majority control by downstream enzymes; and (3) equivalent mutations in enzyme kinetic rates have the greatest effect on flux for enzymes with high levels of flux control, and these enzymes will accumulate adaptive substitutions, strengthening their

  14. Integration of Posttranscriptional Gene Networks into Metabolic Adaptation and Biofilm Maturation in Candida albicans.

    Verma-Gaur, Jiyoti; Qu, Yue; Harrison, Paul F; Lo, Tricia L; Quenault, Tara; Dagley, Michael J; Bellousoff, Matthew; Powell, David R; Beilharz, Traude H; Traven, Ana

    2015-10-01

    The yeast Candida albicans is a human commensal and opportunistic pathogen. Although both commensalism and pathogenesis depend on metabolic adaptation, the regulatory pathways that mediate metabolic processes in C. albicans are incompletely defined. For example, metabolic change is a major feature that distinguishes community growth of C. albicans in biofilms compared to suspension cultures, but how metabolic adaptation is functionally interfaced with the structural and gene regulatory changes that drive biofilm maturation remains to be fully understood. We show here that the RNA binding protein Puf3 regulates a posttranscriptional mRNA network in C. albicans that impacts on mitochondrial biogenesis, and provide the first functional data suggesting evolutionary rewiring of posttranscriptional gene regulation between the model yeast Saccharomyces cerevisiae and C. albicans. A proportion of the Puf3 mRNA network is differentially expressed in biofilms, and by using a mutant in the mRNA deadenylase CCR4 (the enzyme recruited to mRNAs by Puf3 to control transcript stability) we show that posttranscriptional regulation is important for mitochondrial regulation in biofilms. Inactivation of CCR4 or dis-regulation of mitochondrial activity led to altered biofilm structure and over-production of extracellular matrix material. The extracellular matrix is critical for antifungal resistance and immune evasion, and yet of all biofilm maturation pathways extracellular matrix biogenesis is the least understood. We propose a model in which the hypoxic biofilm environment is sensed by regulators such as Ccr4 to orchestrate metabolic adaptation, as well as the regulation of extracellular matrix production by impacting on the expression of matrix-related cell wall genes. Therefore metabolic changes in biofilms might be intimately linked to a key biofilm maturation mechanism that ultimately results in untreatable fungal disease. PMID:26474309

  15. Integration of Posttranscriptional Gene Networks into Metabolic Adaptation and Biofilm Maturation in Candida albicans.

    Jiyoti Verma-Gaur

    2015-10-01

    Full Text Available The yeast Candida albicans is a human commensal and opportunistic pathogen. Although both commensalism and pathogenesis depend on metabolic adaptation, the regulatory pathways that mediate metabolic processes in C. albicans are incompletely defined. For example, metabolic change is a major feature that distinguishes community growth of C. albicans in biofilms compared to suspension cultures, but how metabolic adaptation is functionally interfaced with the structural and gene regulatory changes that drive biofilm maturation remains to be fully understood. We show here that the RNA binding protein Puf3 regulates a posttranscriptional mRNA network in C. albicans that impacts on mitochondrial biogenesis, and provide the first functional data suggesting evolutionary rewiring of posttranscriptional gene regulation between the model yeast Saccharomyces cerevisiae and C. albicans. A proportion of the Puf3 mRNA network is differentially expressed in biofilms, and by using a mutant in the mRNA deadenylase CCR4 (the enzyme recruited to mRNAs by Puf3 to control transcript stability we show that posttranscriptional regulation is important for mitochondrial regulation in biofilms. Inactivation of CCR4 or dis-regulation of mitochondrial activity led to altered biofilm structure and over-production of extracellular matrix material. The extracellular matrix is critical for antifungal resistance and immune evasion, and yet of all biofilm maturation pathways extracellular matrix biogenesis is the least understood. We propose a model in which the hypoxic biofilm environment is sensed by regulators such as Ccr4 to orchestrate metabolic adaptation, as well as the regulation of extracellular matrix production by impacting on the expression of matrix-related cell wall genes. Therefore metabolic changes in biofilms might be intimately linked to a key biofilm maturation mechanism that ultimately results in untreatable fungal disease.

  16. Metabolic Plasticity of Metastatic Breast Cancer Cells: Adaptation to Changes in the Microenvironment

    Rui V. Simões

    2015-08-01

    Full Text Available Cancer cells adapt their metabolism during tumorigenesis. We studied two isogenic breast cancer cells lines (highly metastatic 4T1; nonmetastatic 67NR to identify differences in their glucose and glutamine metabolism in response to metabolic and environmental stress. Dynamic magnetic resonance spectroscopy of 13C-isotopomers showed that 4T1 cells have higher glycolytic and tricarboxylic acid (TCA cycle flux than 67NR cells and readily switch between glycolysis and oxidative phosphorylation (OXPHOS in response to different extracellular environments. OXPHOS activity increased with metastatic potential in isogenic cell lines derived from the same primary breast cancer: 4T1 > 4T07 and 168FARN (local micrometastasis only > 67NR. We observed a restricted TCA cycle flux at the succinate dehydrogenase step in 67NR cells (but not in 4T1 cells, leading to succinate accumulation and hindering OXPHOS. In the four isogenic cell lines, environmental stresses modulated succinate dehydrogenase subunit A expression according to metastatic potential. Moreover, glucose-derived lactate production was more glutamine dependent in cell lines with higher metastatic potential. These studies show clear differences in TCA cycle metabolism between 4T1 and 67NR breast cancer cells. They indicate that metastases-forming 4T1 cells are more adept at adjusting their metabolism in response to environmental stress than isogenic, nonmetastatic 67NR cells. We suggest that the metabolic plasticity and adaptability are more important to the metastatic breast cancer phenotype than rapid cell proliferation alone, which could 1 provide a new biomarker for early detection of this phenotype, possibly at the time of diagnosis, and 2 lead to new treatment strategies of metastatic breast cancer by targeting mitochondrial metabolism.

  17. Cholesterol Metabolism and Weight Reduction in Subjects with Mild Obstructive Sleep Apnoea: A Randomised, Controlled Study

    Maarit Hallikainen

    2013-01-01

    Full Text Available To evaluate whether parameters of obstructive sleep apnoea (OSA associate with cholesterol metabolism before and after weight reduction, 42 middle-aged overweight subjects with mild OSA were randomised to intensive lifestyle intervention (N=23 or to control group (N=18 with routine lifestyle counselling only. Cholesterol metabolism was evaluated with serum noncholesterol sterol ratios to cholesterol, surrogate markers of cholesterol absorption (cholestanol and plant sterols and synthesis (cholestenol, desmosterol, and lathosterol at baseline and after 1-year intervention. At baseline, arterial oxygen saturation (SaO2 was associated with serum campesterol (P<0.05 and inversely with desmosterol ratios (P<0.001 independently of gender, BMI, and homeostasis model assessment index of insulin resistance (HOMA-IR. Apnoea-hypopnoea index (AHI was not associated with cholesterol metabolism. Weight reduction significantly increased SaO2and serum cholestanol and decreased AHI and serum cholestenol ratios. In the groups combined, the changes in AHI were inversely associated with changes of cholestanol and positively with cholestenol ratios independent of gender and the changes of BMI and HOMA-IR (P<0.05. In conclusion, mild OSA seemed to be associated with cholesterol metabolism independent of BMI and HOMA-IR. Weight reduction increased the markers of cholesterol absorption and decreased those of cholesterol synthesis in the overweight subjects with mild OSA.

  18. Monitoring and robust adaptive control of fed-batch cultures of microorganisms exhibiting overflow metabolism [abstract

    Vande Wouwer, A.

    2010-01-01

    Full Text Available Overflow metabolism characterizes cells strains that are likely to produce inhibiting by-products resulting from an excess of substrate feeding and a saturated respiratory capacity. The critical substrate level separating the two different metabolic pathways is generally not well defined. Monitoring of this kind of cultures, going from model identification to state estimation, is first discussed. Then, a review of control techniques which all aim at maximizing the cell productivity of fed-batch fermentations is presented. Two main adaptive control strategies, one using an estimation of the critical substrate level as set-point and another regulating the by-product concentration, are proposed. Finally, experimental investigations of an adaptive RST control scheme using the observer polynomial for the regulation of the ethanol concentration in Saccharomyces cerevisiae fed-batch cultures ranging from laboratory to industrial scales, are also presented.

  19. Reductive metabolism of oxymatrine is catalyzed by microsomal CYP3A4

    Liu W

    2015-10-01

    Full Text Available Wenqin Liu,1,2,* Jian Shi,1,2,* Lijun Zhu,2 Lingna Dong,1 Feifei Luo,2 Min Zhao,2 Ying Wang,2 Ming Hu,2,3 Linlin Lu,2 Zhongqiu Liu1,2 1Department of Pharmaceutics, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong, People’s Republic of China; 2International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People’s Republic of China; 3Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX, USA *These authors contributed equally to this work Abstract: Oxymatrine (OMT is a pharmacologically active primary quinolizidine alkaloid with various beneficial and toxic effects. It is confirmed that, after oral administration, OMT could be transformed to the more toxic metabolite matrine (MT, and this process may be through the reduction reaction, but the study on the characteristics of this transformation is limited. The aim of this study was to investigate the characteristics of this transformation of OMT in the human liver microsomes (HLMs and human intestinal microsomes (HIMs and the cytochrome P450 (CYP isoforms involved in this transformation. The current studies demonstrated that OMT could be metabolized to MT rapidly in HLMs and HIMs and CYP3A4 greatly contributed to this transformation. All HLMs, HIMs, and CYP3A4 isoform mediated reduction reaction followed typical biphasic kinetic model, and Km, Vmax, and CL were significant higher in HLMs than those in HIMs. Importantly, different oxygen contents could significantly affect the metabolism of OMT, and with the oxygen content decreased, the formation of metabolite was increased, suggesting this transformation was very likely a reduction reaction. Results of this in vitro study elucidated the metabolic pathways and characteristics of metabolism of OMT to MT and would provide a theoretical basis and guidance for the safe application of OMT

  20. Adaptive Control Model Reveals Systematic Feedback and Key Molecules in Metabolic Pathway Regulation

    Quo, Chang F.; Moffitt, Richard A; Merrill, Alfred H.; Wang, May D.

    2011-01-01

    Robust behavior in metabolic pathways resembles stabilized performance in systems under autonomous control. This suggests we can apply control theory to study existing regulation in these cellular networks. Here, we use model-reference adaptive control (MRAC) to investigate the dynamics of de novo sphingolipid synthesis regulation in a combined theoretical and experimental case study. The effects of serine palmitoyltransferase over-expression on this pathway are studied in vitro using human e...

  1. Coregulation of host-adapted metabolism and virulence by pathogenic yersiniae

    Ann Kathrin eHeroven; Petra eDersch

    2014-01-01

    Deciphering the principles how pathogenic bacteria adapt their metabolism to a specific host microenvironment is critical for understanding bacterial pathogenesis. The enteric pathogenic Yersinia species Y. pseudotuberculosis and Y. enterocolitica and the causative agent of plague, Y. pestis, are able to survive in a large variety of environmental reservoirs (e.g. soil, plants, insects) as well as warm-blooded animals (e.g. rodents, pigs, humans) with a particular preference for lymphatic tis...

  2. Altered myocardial metabolic adaptation to increased fatty acid availability in cardiomyocyte-specific CLOCK mutant mice.

    Peliciari-Garcia, Rodrigo A; Goel, Mehak; Aristorenas, Jonathan A; Shah, Krishna; He, Lan; Yang, Qinglin; Shalev, Anath; Bailey, Shannon M; Prabhu, Sumanth D; Chatham, John C; Gamble, Karen L; Young, Martin E

    2016-10-01

    A mismatch between fatty acid availability and utilization leads to cellular/organ dysfunction during cardiometabolic disease states (e.g., obesity, diabetes mellitus). This can precipitate cardiac dysfunction. The heart adapts to increased fatty acid availability at transcriptional, translational, post-translational and metabolic levels, thereby attenuating cardiomyopathy development. We have previously reported that the cardiomyocyte circadian clock regulates transcriptional responsiveness of the heart to acute increases in fatty acid availability (e.g., short-term fasting). The purpose of the present study was to investigate whether the cardiomyocyte circadian clock plays a role in adaptation of the heart to chronic elevations in fatty acid availability. Fatty acid availability was increased in cardiomyocyte-specific CLOCK mutant (CCM) and wild-type (WT) littermate mice for 9weeks in time-of-day-independent (streptozotocin (STZ) induced diabetes) and dependent (high fat diet meal feeding) manners. Indices of myocardial metabolic adaptation (e.g., substrate reliance perturbations) to STZ-induced diabetes and high fat meal feeding were found to be dependent on genotype. Various transcriptional and post-translational mechanisms were investigated, revealing that Cte1 mRNA induction in the heart during STZ-induced diabetes is attenuated in CCM hearts. At the functional level, time-of-day-dependent high fat meal feeding tended to influence cardiac function to a greater extent in WT versus CCM mice. Collectively, these data suggest that CLOCK (a circadian clock component) is important for metabolic adaption of the heart to prolonged elevations in fatty acid availability. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk. PMID:26721420

  3. How the edaphic Bacillus megaterium strain Mes11 adapts its metabolism to the herbicide mesotrione pressure

    Toxicity of pesticides towards microorganisms can have a major impact on ecosystem function. Nevertheless, some microorganisms are able to respond quickly to this stress by degrading these molecules. The edaphic Bacillus megaterium strain Mes11 can degrade the herbicide mesotrione. In order to gain insight into the cellular response involved, the intracellular proteome of Mes11 exposed to mesotrione was analyzed using the two-dimensional differential in-gel electrophoresis (2D-DIGE) approach coupled with mass spectrometry. The results showed an average of 1820 protein spots being detected. The gel profile analyses revealed 32 protein spots whose abundance is modified after treatment with mesotrione. Twenty spots could be identified, leading to 17 non redundant proteins, mainly involved in stress, metabolic and storage mechanisms. These findings clarify the pathways used by B. megaterium strain Mes11 to resist and adapt to the presence of mesotrione. - Highlights: • Bacillus megaterium strain Mes11 is able to degrade the herbicide mesotrione. • The response to mesotrione stress was studied by a differential proteomic approach. • Adaptation to mesotrione involves stress, central metabolism and storage proteins. • Some identified proteins could be directly involved in mesotrione degradation. - Metabolism adaptation of the mesotrione-degrading Bacillus megaterium to the mesotrione herbicide stress

  4. Adaptive Benefits of Storage Strategy and Dual AMPK/TOR Signaling in Metabolic Stress Response.

    Pfeuty, Benjamin; Thommen, Quentin

    2016-01-01

    Cellular metabolism must ensure that supply of nutrient meets the biosynthetic and bioenergetic needs. Cells have therefore developed sophisticated signaling and regulatory pathways in order to cope with dynamic fluctuations of both resource and demand and to regulate accordingly diverse anabolic and catabolic processes. Intriguingly, these pathways are organized around a relatively small number of regulatory hubs, such as the highly conserved AMPK and TOR kinase families in eukaryotic cells. Here, the global metabolic adaptations upon dynamic environment are investigated using a prototypical model of regulated metabolism. In this model, the optimal enzyme profiles as well as the underlying regulatory architecture are identified by combining perturbation and evolutionary methods. The results reveal the existence of distinct classes of adaptive strategies, which differ in the management of storage reserve depending on the intensity of the stress and in the regulation of ATP-producing reaction depending on the nature of the stress. The regulatory architecture that optimally implements these adaptive features is characterized by a crosstalk between two specialized signaling pathways, which bears close similarities with the sensing and regulatory properties of AMPK and TOR pathways. PMID:27505075

  5. Metabolic adaptation and trophic strategies of soil bacteria - C1- metabolism and sulfur chemolithotrophy in Starkeya novella

    UlrikeKappler

    2013-10-01

    Full Text Available The highly diverse and metabolically versatile microbial communities found in soil environments are major contributors to the global carbon, nitrogen and sulfur cycles. We have used a combination of genome –based pathway analysis with proteomics and gene expression studies to investigate metabolic adaptation in a representative of these bacteria, Starkeya novella, which was originally isolated from agricultural soil. This bacterium was the first facultative sulfur chemolithoautotroph that was isolated and it is also able to grow with methanol and on over 39 substrates as a heterotroph. However, using glucose, fructose, methanol, thiosulfate as well as combinations of the carbon compounds with thiosulfate as growth substrates we have demonstrated here that contrary to the previous classification, S. novella is not a facultative sulfur chemolitho- and methylotroph, as the enzyme systems required for these two growth modes as always expressed at high levels. This is typical for key metabolic pathways. In addition enzymes for various pathways of carbon dioxide fixation were always expressed at high levels, even during heterotrophic growth on glucose or fructose, which suggests a role for these pathways beyond the generation of reduced carbon units for cell growth, possibly in redox balancing of metabolism. Our results then indicate that S. novella, a representative of the Xanthobacteraceae family of methylotrophic soil and freshwater dwelling bacteria, employs a mixotrophic growth strategy under all conditions tested here. As a result the contribution of this bacterium to either carbon sequestration or the release of climate active substances could vary very quickly, which has direct implications for the modelling of such processes if mixotrophy proves to be the main growth strategy for large populations of soil bacteria.

  6. An adaptive optics approach to the reduction of misalignments and beam jitters in gravitational wave interferometers

    We describe a study and the preliminary experimental results on the possibility of using adaptive optics systems for the reduction of geometrical fluctuations of input laser beams in long baseline interferometric detectors of gravitational waves. The experimental tests aimed to test the efficiency of Hermite-Gauss versus Shack-Hartmann wavefront reconstruction and feedback diagonalization. These preliminary results seem to indicate that the adaptive optics systems may be integrated in the near future as stabilization stages before a passive mode cleaner cavity, provided that the operational band of the mirror is increased together with the efficiency of the control system

  7. Cr isotope fractionation factors for Cr(VI) reduction by a metabolically diverse group of bacteria

    Basu, Anirban; Johnson, Thomas M.; Sanford, Robert A.

    2014-10-01

    Reduction of Cr(VI) is an important process that determines the geochemical behavior, mobility and bioavailability of Cr in both terrestrial and marine environments. Many metabolically diverse microorganisms possess Cr(VI) reduction capacity. Cr(VI) reduction fractionates Cr isotopes and thus 53Cr/52Cr ratios can be used to monitor Cr(VI) reduction and redox conditions. The magnitude of isotopic fractionation (ε) for a variety of microbial reduction mechanisms must be known for accurate interpretation of observed shifts in 53Cr/52Cr ratios. We determined isotopic fractionation factors for Cr(VI) reduction by metal reducers Geobacter sulfurreducens and Shewanella sp. strain NR, a denitrifying soil bacterium Pseudomonas stutzeri DCP-Ps1, and a sulfate reducer Desulfovibrio vulgaris. All bacteria investigated in this study produced significant Cr isotope fractionation. The fractionation (ε) for G. sulfurreducens, Shewanella sp. (NR), P. stutzeri DCP-Ps1, and D. vulgaris were -3.03‰ ± 0.12‰, -2.17‰ ± 0.22‰, -3.14‰ ± 0.13‰, and -3.01‰ ± 0.11‰, respectively. Despite differences in microbial strains in this study, the ε did not vary significantly except for Shewanella sp. (NR). Our results suggest that strong isotopic fractionation is induced during Cr(VI) reduction under electron donor poor (∼300 μM) conditions.

  8. An adaptive model order reduction by proper snapshot selection for nonlinear dynamical problems

    Nigro, P. S. B.; Anndif, M.; Teixeira, Y.; Pimenta, P. M.; Wriggers, P.

    2016-04-01

    Model Order Reduction (MOR) methods are employed in many fields of Engineering in order to reduce the processing time of complex computational simulations. A usual approach to achieve this is the application of Galerkin projection to generate representative subspaces (reduced spaces). However, when strong nonlinearities in a dynamical system are present and this technique is employed several times along the simulation, it can be very inefficient. This work proposes a new adaptive strategy, which ensures low computational cost and small error to deal with this problem. This work also presents a new method to select snapshots named Proper Snapshot Selection (PSS). The objective of the PSS is to obtain a good balance between accuracy and computational cost by improving the adaptive strategy through a better snapshot selection in real time (online analysis). With this method, it is possible a substantial reduction of the subspace, keeping the quality of the model without the use of the Proper Orthogonal Decomposition (POD).

  9. Sustainable development through a gendered lens: climate change adaptation and disaster risk reduction.

    Lewis, Nancy D

    2016-03-01

    The UN General Assembly has just adopted the post 2015 Sustainable Development Agenda articulated in the 17 Sustainable Development Goals (SDGs). Achieving the SDGs will be furthered by the closer integration of the climate change adaptation (CCA) and disaster risk reduction (DRR) agendas. Gender provides us a valuable portal for considering this integration. Acknowledging that gender relaters to both women and men and that men and women experience climate variability and disasters differently, in this paper the role of women in both CCA and DRR is explored, shifting the focus from women as vulnerable victims to women as critical agents for change with respect to climate change mitigation and adaptation and reduction of disaster risks. Appropriately targeted interventions can also empower women and contribute to more just and inclusive sustainable development. PMID:26943600

  10. Adaptive Modified Hysteresis Current Control for Reduction of Switching Losses in Grid Connected Solar Inverters

    Preethi Thekkath

    2014-06-01

    Full Text Available Current Control logic plays an important role in the performance of Grid connected inverters. In the present work Adaptive Modified Hysteresis controller has been used for generation of switching pulses to the minimally switched grid connected inverter. Different from the previous works the new control logic helps in maintaining the instantaneous switching frequency low and nearly constant with reduction of switching losses to one-third of that of the conventional type. Considerable reduction in Total harmonic distortion of supply current, better DC bus voltage stabilization, good reactive power compensation, satisfactory performance under unbalanced source and load conditions and good dynamic response is also achieved. The experimental verification is done using SIMULINK/REALTIME WINDOWS TARGET. Present control logic is compared with conventional hysteresis controller with and without adaptive control to prove the effectiveness.

  11. Design of a Low-Power VLSI Macrocell for Nonlinear Adaptive Video Noise Reduction

    Fanucci Luca; Saponara Sergio; Terreni Pierangelo

    2004-01-01

    A VLSI macrocell for edge-preserving video noise reduction is proposed in the paper. It is based on a nonlinear rational filter enhanced by a noise estimator for blind and dynamic adaptation of the filtering parameters to the input signal statistics. The VLSI filter features a modular architecture allowing the extension of both mask size and filtering directions. Both spatial and spatiotemporal algorithms are supported. Simulation results with monochrome test videos prove its efficiency for ...

  12. Effects of directional microphone and adaptive multichannel noise reduction algorithm on cochlear implant performance

    Chung, K.; Zeng, F G; Acker, K N

    2006-01-01

    Although cochlear implant (CI) users have enjoyed good speech recognition in quiet, they still have difficulties understanding speech in noise. We conducted three experiments to determine whether a directional microphone and an adaptive multichannel noise reduction algorithm could enhance Cl performance in noise and whether Speech Transmission Index (STI) can be used to predict CI performance in various acoustic and signal processing conditions. In Experiment 1, CI users listened to speech in...

  13. An adaptive model reduction strategy for post-buckling analysis of stiffened structures

    Barrière, Ludovic; Marguet, Steven; Castanié, Bruno; Cresta, Philippe; Passieux, Jean-Charles

    2013-01-01

    The finite element simulation of structures subjected to post-buckling still faces computational limits, especially for large stiffened structures. Several solving strategies have already been proposed in response to this issue. Among them are the adaptive model reduction solving techniques which demonstrated their ability to drastically reduce the number of unknowns as well as to control the approximation error of solving non-linear problems like post-buckling. The challenges regarding these...

  14. Metabolic Implications of Surgical Fat Removal: Increase of Adiponectin Plasma Levels After Reduction Mammaplasty and Abdominoplasty.

    Vinci, Valeriano; Valaperta, Serenella; Klinger, Marco; Montanelli, Alessandro; Specchia, Claudia; Forcellini, Davide; Maione, Luca; Klinger, Francesco Maria; Caviggioli, Fabio

    2016-06-01

    Recent studies tried to identify new indicators of risk in the development of insulin resistance, cardiovascular disease, and metabolic syndrome; recently, breast size has been proposed as a new measure of risk for type 2 diabetes mellitus in women. To understand the role of breast adipose tissue and subcutaneous adipose tissue in lipidic and glucose metabolism, we decided to evaluate the variation on levels of adiponectin in plasma and other well-known metabolic markers before and after surgical fat reduction.We formed 2 groups: breast reduction group (M-) and abdominoplasty group (ADD). For all patients enrolled in the study, we recorded anthropometric measurements 1 hour before surgery (that we considered as time zero). At time zero, we always performed a blood sample to observe the assay of glucose, total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, CRP, TNF-α, IL-1, IL-6, and adiponectin. The dosage of the above parameters was repeated 40 days after the surgical intervention with the aim of assessing whether they showed a statistically significant change after surgery.Adiponectin levels increased significantly in both groups of patients after surgery: in patients undergoing reduction mammaplasty and abdominoplasty, the mean increase was equal to 1.68 (P = 0.007) and 4.28 (P = 0.019), respectively. The variation in increase was not statistically different between the 2 groups (P = 0.254).Moreover, in the M- group, we observed that HDL levels increased and glycemia decreased significantly.Our study shows that reduction mammaplasty is a surgical procedure associated with a significant improvement in adiponectin level, HDL cholesterol level, and a significant decrease in glycemia level.The effective correlation between the role of breast adipose tissue and appearance of disease is still to be determined. PMID:25003417

  15. Co-evolution of Hormone Metabolism and Signaling Networks Expands Plant Adaptive Plasticity.

    Weng, Jing-Ke; Ye, Mingli; Li, Bin; Noel, Joseph P

    2016-08-11

    Classically, hormones elicit specific cellular responses by activating dedicated receptors. Nevertheless, the biosynthesis and turnover of many of these hormone molecules also produce chemically related metabolites. These molecules may also possess hormonal activities; therefore, one or more may contribute to the adaptive plasticity of signaling outcomes in host organisms. Here, we show that a catabolite of the plant hormone abscisic acid (ABA), namely phaseic acid (PA), likely emerged in seed plants as a signaling molecule that fine-tunes plant physiology, environmental adaptation, and development. This trait was facilitated by both the emergence-selection of a PA reductase that modulates PA concentrations and by the functional diversification of the ABA receptor family to perceive and respond to PA. Our results suggest that PA serves as a hormone in seed plants through activation of a subset of ABA receptors. This study demonstrates that the co-evolution of hormone metabolism and signaling networks can expand organismal resilience. PMID:27518563

  16. Physical activity: benefit or weakness in metabolic adaptations in a mouse model of chronic food restriction?

    Méquinion, Mathieu; Caron, Emilie; Zgheib, Sara; Stievenard, Aliçia; Zizzari, Philippe; Tolle, Virginie; Cortet, Bernard; Lucas, Stéphanie; Prévot, Vincent; Chauveau, Christophe; Viltart, Odile

    2015-02-01

    In restrictive-type anorexia nervosa (AN) patients, physical activity is usually associated with food restriction, but its physiological consequences remain poorly characterized. In female mice, we evaluated the impact of voluntary physical activity with/without chronic food restriction on metabolic and endocrine parameters that might contribute to AN. In this protocol, FRW mice (i.e., food restriction with running wheel) reached a crucial point of body weight loss (especially fat mass) faster than FR mice (i.e., food restriction only). However, in contrast to FR mice, their body weight stabilized, demonstrating a protective effect of a moderate, regular physical activity. Exercise delayed meal initiation and duration. FRW mice displayed food anticipatory activity compared with FR mice, which was strongly diminished with the prolongation of the protocol. The long-term nature of the protocol enabled assessment of bone parameters similar to those observed in AN patients. Both restricted groups adapted their energy metabolism differentially in the short and long term, with less fat oxidation in FRW mice and a preferential use of glucose to compensate for the chronic energy imbalance. Finally, like restrictive AN patients, FRW mice exhibited low leptin levels, high plasma concentrations of corticosterone and ghrelin, and a disruption of the estrous cycle. In conclusion, our model suggests that physical activity has beneficial effects on the adaptation to the severe condition of food restriction despite the absence of any protective effect on lean and bone mass. PMID:25465889

  17. Metabolic modelling reveals the specialization of secondary replicons for niche adaptation in Sinorhizobium meliloti.

    diCenzo, George C; Checcucci, Alice; Bazzicalupo, Marco; Mengoni, Alessio; Viti, Carlo; Dziewit, Lukasz; Finan, Turlough M; Galardini, Marco; Fondi, Marco

    2016-01-01

    The genome of about 10% of bacterial species is divided among two or more large chromosome-sized replicons. The contribution of each replicon to the microbial life cycle (for example, environmental adaptations and/or niche switching) remains unclear. Here we report a genome-scale metabolic model of the legume symbiont Sinorhizobium meliloti that is integrated with carbon utilization data for 1,500 genes with 192 carbon substrates. Growth of S. meliloti is modelled in three ecological niches (bulk soil, rhizosphere and nodule) with a focus on the role of each of its three replicons. We observe clear metabolic differences during growth in the tested ecological niches and an overall reprogramming following niche switching. In silico examination of the inferred fitness of gene deletion mutants suggests that secondary replicons evolved to fulfil a specialized function, particularly host-associated niche adaptation. Thus, genes on secondary replicons might potentially be manipulated to promote or suppress host interactions for biotechnological purposes. PMID:27447951

  18. Online Adaptive Local-Global Model Reduction for Flows in Heterogeneous Porous Media

    Efendiev, Yalchin

    2016-06-07

    We propose an online adaptive local-global POD-DEIM model reduction method for flows in heterogeneous porous media. The main idea of the proposed method is to use local online indicators to decide on the global update, which is performed via reduced cost local multiscale basis functions. This unique local-global online combination allows (1) developing local indicators that are used for both local and global updates (2) computing global online modes via local multiscale basis functions. The multiscale basis functions consist of offline and some online local basis functions. The approach used for constructing a global reduced system is based on Proper Orthogonal Decomposition (POD) Galerkin projection. The nonlinearities are approximated by the Discrete Empirical Interpolation Method (DEIM). The online adaption is performed by incorporating new data, which become available at the online stage. Once the criterion for updates is satisfied, we adapt the reduced system online by changing the POD subspace and the DEIM approximation of the nonlinear functions. The main contribution of the paper is that the criterion for adaption and the construction of the global online modes are based on local error indicators and local multiscale basis function which can be cheaply computed. Since the adaption is performed infrequently, the new methodology does not add significant computational overhead associated with when and how to adapt the reduced basis. Our approach is particularly useful for situations where it is desired to solve the reduced system for inputs or controls that result in a solution outside the span of the snapshots generated in the offline stage. Our method also offers an alternative of constructing a robust reduced system even if a potential initial poor choice of snapshots is used. Applications to single-phase and two-phase flow problems demonstrate the efficiency of our method.

  19. Urinary Metabolite Profiles in Premature Infants Show Early Postnatal Metabolic Adaptation and Maturation

    Sissel J. Moltu

    2014-05-01

    Full Text Available Objectives: Early nutrition influences metabolic programming and long-term health. We explored the urinary metabolite profiles of 48 premature infants (birth weight < 1500 g randomized to an enhanced or a standard diet during neonatal hospitalization. Methods: Metabolomics using nuclear magnetic resonance spectroscopy (NMR was conducted on urine samples obtained during the first week of life and thereafter fortnightly. Results: The intervention group received significantly higher amounts of energy, protein, lipids, vitamin A, arachidonic acid and docosahexaenoic acid as compared to the control group. Enhanced nutrition did not appear to affect the urine profiles to an extent exceeding individual variation. However, in all infants the glucogenic amino acids glycine, threonine, hydroxyproline and tyrosine increased substantially during the early postnatal period, along with metabolites of the tricarboxylic acid cycle (succinate, oxoglutarate, fumarate and citrate. The metabolite changes correlated with postmenstrual age. Moreover, we observed elevated threonine and glycine levels in first-week urine samples of the small for gestational age (SGA; birth weight < 10th percentile for gestational age as compared to the appropriate for gestational age infants. Conclusion: This first nutri-metabolomics study in premature infants demonstrates that the physiological adaptation during the fetal-postnatal transition as well as maturation influences metabolism during the breastfeeding period. Elevated glycine and threonine levels were found in the first week urine samples of the SGA infants and emerged as potential biomarkers of an altered metabolic phenotype.

  20. SEVERE OBESITY SHIFTS METABOLIC THRESHOLDS BUT DOES NOT ATTENUATE AEROBIC TRAINING ADAPTATIONS IN ZUCKER RATS

    Thiago Santos Rosa

    2016-04-01

    Full Text Available Severe obesity affects metabolism with potential to influence the lactate and glycemic response to different exercise intensities in untrained and trained rats. Here we evaluated metabolic thresholds and maximal aerobic capacity in rats with severe obesity and lean counterparts at pre- and post-training. Zucker rats (obese: n = 10, lean: n = 10 were submitted to constant treadmill bouts, to determine the maximal lactate steady state, and an incremental treadmill test, to determine the lactate threshold, glycemic threshold and maximal velocity at pre and post 8 weeks of treadmill training. Velocities of the lactate threshold and glycemic threshold agreed with the maximal lactate steady state velocity on most comparisons. The maximal lactate steady state velocity occurred at higher percentage of the maximal velocity in Zucker rats at pre-training than the percentage commonly reported and used for training prescription for other rat strains (i.e., 60% (obese = 78±9% and lean = 68±5%, P 0.05, whereas increase in maximal velocity was greater in the obese group (P <0.05 vs. lean. In conclusion, lactate threshold, glycemic threshold and maximal lactate steady state occurred at similar exercise intensity in Zucker rats at pre- and post-training. Severe obesity shifted metabolic thresholds to higher exercise intensity at pre-training, but did not attenuate submaximal and maximal aerobic training adaptations.

  1. Chemotactic signal transduction and phosphate metabolism as adaptive strategies during citrus canker induction by Xanthomonas citri.

    Moreira, Leandro Marcio; Facincani, Agda Paula; Ferreira, Cristiano Barbalho; Ferreira, Rafael Marine; Ferro, Maria Inês Tiraboshi; Gozzo, Fabio Cesar; de Oliveira, Julio Cezar Franco; Ferro, Jesus Aparecido; Soares, Márcia Regina

    2015-03-01

    The genome of Xanthomonas citri subsp. Citri strain 306 pathotype A (Xac) was completely sequenced more than 10 years; to date, few studies involving functional genomics Xac and its host compatible have been developed, specially related to adaptive events that allow the survival of Xac within the plant. Proteomic analysis of Xac showed that the processes of chemotactic signal transduction and phosphate metabolism are key adaptive strategies during the interaction of a pathogenic bacterium with its plant host. The results also indicate the importance of a group of proteins that may not be directly related to the classical virulence factors, but that are likely fundamental to the success of the initial stages of the infection, such as methyl-accepting chemotaxis protein (Mcp) and phosphate specific transport (Pst). Furthermore, the analysis of the mutant of the gene pstB which codifies to an ABC phosphate transporter subunit revealed a complete absence of citrus canker symptoms when inoculated in compatible hosts. We also conducted an in silico analysis which established the possible network of genes regulated by two-component systems PhoPQ and PhoBR (related to phosphate metabolism), and possible transcriptional factor binding site (TFBS) motifs of regulatory proteins PhoB and PhoP, detaching high degree of conservation of PhoB TFBS in 84 genes of Xac genome. This is the first time that chemotaxis signal transduction and phosphate metabolism were therefore indicated to be fundamental to the process of colonization of plant tissue during the induction of disease associated with Xanthomonas genus bacteria. PMID:25403594

  2. Thermal and metabolic adaptation to first cold-water immersion in juvenile penguins.

    Barré, H; Roussel, B

    1986-09-01

    Juvenile king and macaroni penguins are terrestrial seabirds and must face an intensive and prolonged energetic demand during their passage from shore to marine life in cold subantarctic seawater. Evidence for progressive thermal adaptation was sought by measurement of metabolic rate (MR) and body (Tb) and skin (Tsk) temperatures in unrestrained, fully immersed penguins. Steady-state responses obtained after the 3rd h of immersion in never-immersed (NI) penguins were compared with those of penguins acclimatized to seawater temperature (A). NI macaroni penguins, unlike NI king penguins, showed a fall in Tb on their first immersion but, once acclimatized, were able to maintain their homeothermy due to an increase (greater than 3.2 W/kg) in regulatory thermogenesis. In NI king penguins, during a simulation of seawater adaptation by 10 successive immersions, MR at 7 degrees C water temperature (Tw) rose from 6.0 to 9.4 W/kg (becoming 3-5 times higher than in air), whereas Tb rose from 37.6 to 38.4 degrees C. In both species occurrence of peak MR at much lower Tw, progressive increase in thermogenesis capacity, and lower conductance in water after adaptation to marine life (28 and 36% less in A king and macaroni penguins, respectively) showed that the passage from shore to marine life consisted of a true cold acclimatization. PMID:3752279

  3. Fetal endocrine and metabolic adaptations to hypoxia: the role of the hypothalamic-pituitary-adrenal axis.

    Newby, Elizabeth A; Myers, Dean A; Ducsay, Charles A

    2015-09-01

    In utero, hypoxia is a significant yet common stress that perturbs homeostasis and can occur due to preeclampsia, preterm labor, maternal smoking, heart or lung disease, obesity, and high altitude. The fetus has the extraordinary capacity to respond to stress during development. This is mediated in part by the hypothalamic-pituitary-adrenal (HPA) axis and more recently explored changes in perirenal adipose tissue (PAT) in response to hypoxia. Obvious ethical considerations limit studies of the human fetus, and fetal studies in the rodent model are limited due to size considerations and major differences in developmental landmarks. The sheep is a common model that has been used extensively to study the effects of both acute and chronic hypoxia on fetal development. In response to high-altitude-induced, moderate long-term hypoxia (LTH), both the HPA axis and PAT adapt to preserve normal fetal growth and development while allowing for responses to acute stress. Although these adaptations appear beneficial during fetal development, they may become deleterious postnatally and into adulthood. The goal of this review is to examine the role of the HPA axis in the convergence of endocrine and metabolic adaptive responses to hypoxia in the fetus. PMID:26173460

  4. Systematic Sensitivity Analysis of Metabolic Controllers During Reductions in Skeletal Muscle Blood Flow

    Radhakrishnan, Krishnan; Cabrera, Marco

    2000-01-01

    An acute reduction in oxygen delivery to skeletal muscle is generally associated with profound derangements in substrate metabolism. Given the complexity of the human bioenergetic system and its components, it is difficult to quantify the interaction of cellular metabolic processes to maintain ATP homeostasis during stress (e.g., hypoxia, ischemia, and exercise). Of special interest is the determination of mechanisms relating tissue oxygenation to observed metabolic responses at the tissue, organ, and whole body levels and the quantification of how changes in oxygen availability affect the pathways of ATP synthesis and their regulation. In this study, we apply a previously developed mathematical model of human bioenergetics to study effects of ischemia during periods of increased ATP turnover (e.g., exercise). By using systematic sensitivity analysis the oxidative phosphorylation rate was found to be the most important rate parameter affecting lactate production during ischemia under resting conditions. Here we examine whether mild exercise under ischemic conditions alters the relative importance of pathways and parameters previously obtained.

  5. Gene regulatory and metabolic adaptation processes of Dinoroseobacter shibae DFL12T during oxygen depletion.

    Laass, Sebastian; Kleist, Sarah; Bill, Nelli; Drüppel, Katharina; Kossmehl, Sebastian; Wöhlbrand, Lars; Rabus, Ralf; Klein, Johannes; Rohde, Manfred; Bartsch, Annekathrin; Wittmann, Christoph; Schmidt-Hohagen, Kerstin; Tielen, Petra; Jahn, Dieter; Schomburg, Dietmar

    2014-05-01

    Metabolic flexibility is the key to the ecological success of the marine Roseobacter clade bacteria. We investigated the metabolic adaptation and the underlying changes in gene expression of Dinoroseobacter shibae DFL12(T) to anoxic life by a combination of metabolome, proteome, and transcriptome analyses. Time-resolved studies during continuous oxygen depletion were performed in a chemostat using nitrate as the terminal electron acceptor. Formation of the denitrification machinery was found enhanced on the transcriptional and proteome level, indicating that D. shibae DFL12(T) established nitrate respiration to compensate for the depletion of the electron acceptor oxygen. In parallel, arginine fermentation was induced. During the transition state, growth and ATP concentration were found to be reduced, as reflected by a decrease of A578 values and viable cell counts. In parallel, the central metabolism, including gluconeogenesis, protein biosynthesis, and purine/pyrimidine synthesis was found transiently reduced in agreement with the decreased demand for cellular building blocks. Surprisingly, an accumulation of poly-3-hydroxybutanoate was observed during prolonged incubation under anoxic conditions. One possible explanation is the storage of accumulated metabolites and the regeneration of NADP(+) from NADPH during poly-3-hydroxybutanoate synthesis (NADPH sink). Although D. shibae DFL12(T) was cultivated in the dark, biosynthesis of bacteriochlorophyll was increased, possibly to prepare for additional energy generation via aerobic anoxygenic photophosphorylation. Overall, oxygen depletion led to a metabolic crisis with partly blocked pathways and the accumulation of metabolites. In response, major energy-consuming processes were reduced until the alternative respiratory denitrification machinery was operative. PMID:24648520

  6. ERROR REDUCTION IN ADAPTIVE FINITE ELEMENT APPROXIMATIONS OF ELLIPTIC OBSTACLE PROBLEMS

    Dietrich Braess; Carsten Carstensen; Ronald H.W. Hoppe

    2009-01-01

    We consider an adaptive finite element method (AFEM) for obstacle problems associated with linear second order elliptic boundary value problems and prove a reduction in the energy norm of the discretization error which leads to R-linear convergence. This result is shown to hold up to a consistency error due to the extension of the discrete multipliers (point functionals) to H-1 and a possible mismatch between the continuous and discrete coincidence and noncoincidence sets. The AFEM is based on a residual-type error estimator consisting of element and edge residuals. The a posteriori error analysis reveals that the significant difference to the unconstrained case lies in the fact that these residuals only have to be taken into account within the discrete noncoincidence set. The proof of the error reduction property uses the reliability and the discrete local efficiency of the estimator as well as a perturbed Galerkin orthogonality. Numerical results are given illustrating the performance of the AFEM.

  7. Powerline interference reduction in ECG signals using empirical wavelet transform and adaptive filtering.

    Singh, Omkar; Sunkaria, Ramesh Kumar

    2015-01-01

    Separating an information-bearing signal from the background noise is a general problem in signal processing. In a clinical environment during acquisition of an electrocardiogram (ECG) signal, The ECG signal is corrupted by various noise sources such as powerline interference (PLI), baseline wander and muscle artifacts. This paper presents novel methods for reduction of powerline interference in ECG signals using empirical wavelet transform (EWT) and adaptive filtering. The proposed methods are compared with the empirical mode decomposition (EMD) based PLI cancellation methods. A total of six methods for PLI reduction based on EMD and EWT are analysed and their results are presented in this paper. The EWT-based de-noising methods have less computational complexity and are more efficient as compared with the EMD-based de-noising methods. PMID:25412942

  8. CS-16THE eEF2 KINASE IS CRITICAL FOR BRAIN TUMOURS ADAPTATION TO METABOLIC STRESS

    Leprivier, Gabriel; Remke, Marc; Rotblat, Barak; Agnihotri, Sameer; Kool, Marcel; Derry, Brent; Pfister, Stefan; Taylor, Michael D.; Sorensen, Poul H.

    2014-01-01

    During tumour progression, brain tumour cells are exposed to metabolic stress, such as nutrient deprivation, due to abnormal tumour vasculature. The ability of tumour cells to respond and manage reduced nutrient availability has a strong impact on tumour outcome. The molecular pathways supporting metabolic adaptation of brain tumour cells to nutrient stress represent potential therapeutic targets which are still not well defined. We report that the translation elongation factor 2 (eEF2) kinas...

  9. Dynamical feedback between circadian clock and sucrose availability explains adaptive response of starch metabolism to various photoperiods

    Feugier, François G.; Satake, Akiko

    2013-01-01

    Plants deal with resource management during all their life. During the day they feed on photosynthetic carbon, sucrose, while storing a part into starch for night use. Careful control of carbon partitioning, starch degradation, and sucrose export rates is crucial to avoid carbon starvation, insuring optimal growth whatever the photoperiod. Efficient regulation of these key metabolic rates can give an evolutionary advantage to plants. Here we propose a model of adaptive starch metabolism in re...

  10. Adaptive intelligent speed control of switched reluctance motors with torque ripple reduction

    Switched reluctance (SR) motors have a wide range of applications in industries, mainly due to the special properties of this motor. However, because of its dynamical nonlinearities, its control is complex. This paper presents an adaptive intelligent control based on the Lyapunov stability theory to control the speed of SR motors with good accuracies and performances. The proposed controller is composed of a speed controller and a torque controller. The main parts of the speed controller are two-fold: (a) the optimal controller, which is based on the Hamilton-Jacobi-Bellman theory and (b) the intelligent controller, which is an adaptive fuzzy controller. The main features of the proposed speed controller are: (1) its independence of the exact parameters of the SR motor such as the inertia of rotor, the viscous friction and the load torque and (2) the robustness to inaccuracies and disturbances. Moreover, the torque ripple reduction is achieved by employing a neural network for torque estimation. The simulation results show good performance of the proposed controller in speed controlling and torque ripple reduction

  11. Adaptive intelligent speed control of switched reluctance motors with torque ripple reduction

    Hajatipour, Majid [Faculty of Electrical Engineering, Iran University of Science and Technology, Narmak, Farjam St., Tehran 16846-13114 (Iran, Islamic Republic of); Farrokhi, Mohammad [Faculty of Electrical Engineering, Iran University of Science and Technology, Narmak, Farjam St., Tehran 16846-13114 (Iran, Islamic Republic of); Center of Excellence for Power System Automation and Operation, Iran University of Science and Technology, Narmak, Farjam St., Tehran 16846-13114 (Iran, Islamic Republic of)], E-mail: farrokhi@iust.ac.ir

    2008-05-15

    Switched reluctance (SR) motors have a wide range of applications in industries, mainly due to the special properties of this motor. However, because of its dynamical nonlinearities, its control is complex. This paper presents an adaptive intelligent control based on the Lyapunov stability theory to control the speed of SR motors with good accuracies and performances. The proposed controller is composed of a speed controller and a torque controller. The main parts of the speed controller are two-fold: (a) the optimal controller, which is based on the Hamilton-Jacobi-Bellman theory and (b) the intelligent controller, which is an adaptive fuzzy controller. The main features of the proposed speed controller are: (1) its independence of the exact parameters of the SR motor such as the inertia of rotor, the viscous friction and the load torque and (2) the robustness to inaccuracies and disturbances. Moreover, the torque ripple reduction is achieved by employing a neural network for torque estimation. The simulation results show good performance of the proposed controller in speed controlling and torque ripple reduction.

  12. Integrating community based disaster risk reduction and climate change adaptation: examples from the Pacific

    A. Gero

    2011-01-01

    Full Text Available It is acknowledged by academics and development practitioners alike that many common strategies addressing community based disaster risk reduction and climate change adaptation duplicate each other. Thus, there is a strong push to integrate the two fields to enhance aid effectiveness and reduce confusion for communities. Examples of community based disaster risk reduction (DRR and climate change adaptation (CCA projects are presented to highlight some of the ways these issues are tackled in the Pacific. Various approaches are employed but all aim to reduce the vulnerability and enhance the resilience of local communities to the impacts of climate change and disasters. By focusing on three case studies, elements of best practice are drawn out to illustrate how DRR and CCA can be integrated for enhanced aid effectiveness, and also look at ways in which these two often overlapping fields can be better coordinated in ongoing and future projects. Projects that address vulnerability holistically, and target the overall needs and capacity of the community are found to be effective in enhancing the resilience of communities. By strategically developing a multi-stakeholder and multi-sector approach, community projects are likely to encapsulate a range of experience and skills that will benefit the community. Furthermore, by incorporating local knowledge, communities are far more likely to be engaged and actively participate in the project. From selected case studies, commonly occurring best practice methods to integrate DRR and CCA are identified and discussed and recommendations on how to overcome the common challenges also presented.

  13. Metabolic adaptations of skeletal muscle to voluntary wheel running exercise in hypertensive heart failure rats

    Schultz, R L; Kullman, E L; Waters, Ryan;

    2013-01-01

    The Spontaneously Hypertensive Heart Failure (SHHF) rat mimics the human progression of hypertension from hypertrophy to heart failure. However, it is unknown whether SHHF animals can exercise at sufficient levels to observe beneficial biochemical adaptations in skeletal muscle. Thirty-seven female...... SHHF and Wistar-Furth (WF) rats were randomized to sedentary (SHHFsed and WFsed) and exercise groups (SHHFex and WFex). The exercise groups had access to running wheels from 6-22 months of age. Hindlimb muscles were obtained for metabolic measures that included mitochondrial enzyme function and...... expression, and glycogen utilization. The SHHFex rats ran a greater distance and duration as compared to the WFex rats (P<0.05), but the WFex rats ran at a faster speed (P<0.05). Skeletal muscle citrate synthase and beta-hydroxyacyl-CoA dehydrogenase enzyme activity was not altered in the SHHFex group, but...

  14. Experience of Climate Change Adaptation; Emic Perception of Community Based Disaster Risk Reduction Programs in Bangladesh

    Rathana peou van den Heuvel

    2013-04-01

    Full Text Available Over 40 years (I/ NGOs together with the Government of Bangladesh (GoB have been working to build the capacity of population at risk to cope with natural disasters. From a response rationale to preparedness one, (I/NGOs together with the GoB struggled to integrate adaptation frame into Disaster Risk Reduction program. Those initial steps were mainly lead by a top down approach. Bangladesh usually pointed as the most vulnerable country in the world, has a long history of different frame of actions and practices toward building both community and individual resilience. Structural poverty and low good governance mechanisms are just some of the factors that jeopardize the gains of development project in general in Bangladesh. Donors and (I/NGO play major roles by shaping not only the national discourse but as well by leading the practices and the methodology that needs to be used at the field. Within couple of years, community based approach has been largely adopted by different institutions as being the right way to deliver intervention that aims at reducing the vulnerability and the enhancing the resilience. It is in this context that this paper offers an insight on how DRR and adaptation is translated at the field level. Through an emic perspective this research aims at confronting the realities of the practices of DRR/ Adaptation by (I/NGOs to the discourse that they communicate.

  15. Characterization of adaptive statistical iterative reconstruction algorithm for dose reduction in CT: A pediatric oncology perspective

    Brady, S. L.; Yee, B. S.; Kaufman, R. A. [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, Tennessee 38105 (United States)

    2012-09-15

    Purpose: This study demonstrates a means of implementing an adaptive statistical iterative reconstruction (ASiR Trade-Mark-Sign ) technique for dose reduction in computed tomography (CT) while maintaining similar noise levels in the reconstructed image. The effects of image quality and noise texture were assessed at all implementation levels of ASiR Trade-Mark-Sign . Empirically derived dose reduction limits were established for ASiR Trade-Mark-Sign for imaging of the trunk for a pediatric oncology population ranging from 1 yr old through adolescence/adulthood. Methods: Image quality was assessed using metrics established by the American College of Radiology (ACR) CT accreditation program. Each image quality metric was tested using the ACR CT phantom with 0%-100% ASiR Trade-Mark-Sign blended with filtered back projection (FBP) reconstructed images. Additionally, the noise power spectrum (NPS) was calculated for three common reconstruction filters of the trunk. The empirically derived limitations on ASiR Trade-Mark-Sign implementation for dose reduction were assessed using (1, 5, 10) yr old and adolescent/adult anthropomorphic phantoms. To assess dose reduction limits, the phantoms were scanned in increments of increased noise index (decrementing mA using automatic tube current modulation) balanced with ASiR Trade-Mark-Sign reconstruction to maintain noise equivalence of the 0% ASiR Trade-Mark-Sign image. Results: The ASiR Trade-Mark-Sign algorithm did not produce any unfavorable effects on image quality as assessed by ACR criteria. Conversely, low-contrast resolution was found to improve due to the reduction of noise in the reconstructed images. NPS calculations demonstrated that images with lower frequency noise had lower noise variance and coarser graininess at progressively higher percentages of ASiR Trade-Mark-Sign reconstruction; and in spite of the similar magnitudes of noise, the image reconstructed with 50% or more ASiR Trade-Mark-Sign presented a more

  16. Metabolic Adaptations of White Lupin Roots and Shoots under Phosphorus Deficiency

    Müller, Julia; Gödde, Victoria; Niehaus, Karsten; Zörb, Christian

    2015-01-01

    White lupin (Lupinus albus L.) is highly adapted to phosphorus-diminished soils. P-deficient white lupin plants modify their root architecture and physiology to acquire sparingly available soil phosphorus. We employed gas chromatography–mass spectrometry (GC-MS) for metabolic profiling of P-deficient white lupins, to investigate biochemical pathways involved in the P-acquiring strategy. After 14 days of P-deficiency, plants showed reduced levels of fructose, glucose, and sucrose in shoots. Phosphorylated metabolites such as glucose-6-phosphate, fructose-6-phosphate, myo-inositol-phosphate and glycerol-3-phosphate were reduced in both shoots and roots. After 22 days of P-deficiency, no effect on shoot or root sugar metabolite levels was found, but the levels of phosphorylated metabolites were further reduced. Organic acids, amino acids and several shikimate pathway products showed enhanced levels in 22-day-old P-deficient roots and shoots. These results indicate that P-deficient white lupins adapt their carbohydrate partitioning between shoot and root in order to supply their growing root system as an early response to P-deficiency. Organic acids are released into the rhizosphere to mobilize phosphorus from soil particles. A longer period of P-deficiency leads to scavenging of Pi from P-containing metabolites and reduced protein anabolism, but enhanced formation of secondary metabolites. The latter can serve as stress protection molecules or actively acquire phosphorus from the soil. PMID:26635840

  17. Effective long term adaptation and metabolic state regulation of ski-racers

    Bakhareva A.S.

    2016-06-01

    Full Text Available Purpose: to scientifically substantiate effective mechanisms of organism’s bio-chemical adaptation of ski-racers in competition period with the help of lipid peroxidation indicators, oxidative modification of proteins and activity of hypothalamus pituitary adrenocortical system. Material: in the research 14 sportsmen of 18-25 years’ age (combined team of university with different level of sportsmanship participated. Assessment of free radical oxidation, anti-oxidant system, cortisol level was fulfilled with the help of indicators’ quantitative analysis by bio-chemical methods applied to blood serum samples. Results: it was found that in the basis of bio-chemical changes under intensive physical loads is increase of catabolic processes’ speed. Change of organism’s metabolic orientation of ski racers at optimal level results in working muscles’ energy supply improvement, increase of energy systems’ power and sports efficiency. Conclusions: Application of interval trainings at stages of preparation to special significant competitions results in expected adaptation and increase of sports efficiency. We also showed their effective role in ensuring long term reactions, conditioning high sports efficiency.

  18. Adaptive ultrasonic speckle reduction based on the slope-facet model.

    Huang, Huan-Chao; Chen, Jau-Yuen; Wang, Sheng-De; Chen, Chung-Ming

    2003-08-01

    The flat-facet model has been implicitly assumed for the structure of the image surface by most conventional speckle-reduction algorithms. However, this model is rarely found in a real ultrasound (US) image. To preserve the higher order structures and to capture the spatially variant property of the speckle, a new adaptive speckle-reduction algorithm, called the symmetrical speckle-reduction filter (SSRF), was developed based on the slope-facet model. The basic idea of the SSRF was to estimate the uncorrupted signal on the largest symmetrical slope facet centered at each target pixel. The symmetry constraint ensured the correctness of the mean value. An empirical speckle model was incorporated to account for the nature of the speckle in US image. A two-stage despeckling strategy was employed to enhance the statistical reliability of each estimate by forming a union of a set of symmetrical despeckling windows. The proposed SSRF algorithm was compared with two filtered-based and one wavelet-based approaches and the experimental results showed that the proposed SSRF outperformed these three previous approaches in both the synthetic images and the clinical US images tested in this study. PMID:12946519

  19. Metabolic and proteomic adaptation of Lactobacillus rhamnosus strains during growth under cheese-like environmental conditions compared to de Man, Rogosa, and Sharpe medium.

    Bove, Claudio Giorgio; De Angelis, Maria; Gatti, Monica; Calasso, Maria; Neviani, Erasmo; Gobbetti, Marco

    2012-11-01

    The aim of this study was to demonstrate the metabolic and proteomic adaptation of Lactobacillus rhamnosus strains, which were isolated at different stages of Parmigiano Reggiano cheese ripening. Compared to de Man, Rogosa, and Sharpe (MRS) broth, cultivation under cheese-like conditions (cheese broth, CB) increased the number of free amino acids used as carbon sources. Compared with growth on MRS or pasteurized and microfiltrated milk, all strains cultivated in CB showed a low synthesis of d,l-lactic acid and elevated levels of acetic acid. The proteomic maps of the five representative strains, showing different metabolic traits, were comparatively determined after growth on MRS and CB media. The amount of intracellular and cell-associated proteins was affected by culture conditions and diversity between strains, depending on their time of isolation. Protein spots showing decreased (62 spots) or increased (59 spot) amounts during growth on CB were identified using MALDI-TOF-MS/MS or LC-nano-ESI-MS/MS. Compared with cultivation on MRS broth, the L. rhamnosus strains cultivated under cheese-like conditions had modified amounts of some proteins responsible for protein biosynthesis, nucleotide, and carbohydrate metabolisms, the glycolysis pathway, proteolytic activity, cell wall, and exopolysaccharide biosynthesis, cell regulation, amino acid, and citrate metabolism, oxidation/reduction processes, and stress responses. PMID:22965658

  20. Reduction of concentrate for bovine sires: Influence on metabolic status and semen quality under production conditions

    The effects of reduced concentrate fed in rations of Holstein Friesian bulls for artificial insemination was evaluated with respect to metabolic status, sexual behaviour, semen production and semen quality during one year. In the first of two studies, twenty bulls were fed diets based on hay, green forage and concentrate according to the standard nutrient requirements for dairy cattle in artificial insemination centres. Bulls were divided into two groups: Group 1 (n = 10, control, 5 kg concentrate) and Group 2 (n = 10, experimental, 1 kg concentrate). Feed, blood semen samples were taken for bromatological analysis, metabolic profile and semen evaluation, respectively. Group 2 had lower plasma concentrations of urea (P<0.001), calcium (P<0.05) and phosphorous (P<0.01). Urea were below the reference range. Season of the year affected lipid metabolite concentrations (P<0.001) and osteotrophic minerals (P<0.05 to P<0.001). Group 2 had better production and quality of semen than did Group 1. In the second study, five bulls were fed as the experimental group in the first study. Time of sampling, season of the year and sire affected the hormonal secretion pattern (P<0.001). There were no differences in testoterone and LH plasma concentrations before and after mounting; however, cortisol concentrations showed a significant raise during the period of maximum excitation. Individual secretion patterns varied between bulls and were related to pathological morphology of reproductive and endocrine organs. The effect of sire was significant on all the indicators of the sperm production, except to percentage of live sperm. Season of the year significantly affected sperm concentration and number of doses of extended sperm produced. It is concluded that a reduction of concentrate in the diet did not affect the metabolic status, sexual behaviour, semen production or sperm quality of sires. 29 refs, 2 figs, 4 tabs

  1. Stereoselectivity in metabolic 3-reduction of tibolone in healthy Chinese female volunteers

    Ming ZUO; Ming-jie GAO; Zhen LIU; Lei CAI; Geng-li DUAN

    2005-01-01

    Aim: To investigate the stereoselectivity in human metabolic 3-reduction oftibolone. Methods: Twenty healthy Chinese female volunteers were given a singleoral dose of tibolone (2.5 mg), and serial blood samples were collected aftertreatment. The plasma concentrations of the two pharmacologically active 3-hydroxyl metabolites of tibolone, 3α-hydroxyl-7-methyl- norethynodrel (3α-HMN)and 3β-hydroxyl-7-methyl- norethynodrel (3β-HMN) in plasma were determinedby using a validated liquid chromatography-mass spectrometry (LC-MS) method.Results: The apparent elimination half-life (T1/2) of 3α-HMN was 1.43±0.52 h, andthat of 3β-HMN was 1.53±0.60 h. Maximum plasma concentrations (Cmax) werefound to be 8.75±4.36 μg/L for 3α-HMN and 3.59±1.81 μg/L for 3β-HMN. Areash-1. L-1 for 3α-HMN and 9.89±4.93 μg.h-1. L-1 for 3β-HMN. Conclusion: Stereoselective differences exist in the pharmacokinetics of tibolone metabolism in humans.

  2. Regional difference of glucose metabolism reduction in equivocal Alzheimer's disease and elderly depressed patients

    The aim of this study was to investigate the difference in cerebral glucose metabolism between patients with equivocal Alzheimer's disease (eAD) and those with elderly major depression (DEP). 31 patients with eAD, 7 patients with DEP, and 15 age matched normal controls were scanned with FDG-PET. Each FDG-PET images was normalized to the cerebellar activity before voxel-voxel analysis using SPM99. In comparison with normal controls, the eAD patents showed the most significant reduction of glucose metabolism (hypometabolism) in anterior inferior temporal gyrus in left, followed by bilateral posterior cingulate, left thalamus, and inferior parietal lobe. Patients with DEP showed hypometabolism in precuneus, inferior and middle frontal gyri in left, and right angular gyrus. Significantly lower activity was found in left inferior temporal gyrus in DEP in comparison to the eAD. Patients with eAD and DEP showed different pattern of hypometabolism, especially in inferior temporal gyrus. FDG brain PET may be useful in differential diagnosis between equivocal Alzheimer's disease and elderly depression

  3. LOSS OF CARDIAC METABOLIC ADAPTATION AND DYSFUNCTION OF THE HEART WITH WESTERN DIET IN THE OBESE ZUCKER RAT

    The normal heart sustains its work output through changing the proportion of substrates it oxidizes depending on fuel supply. This metabolic adaptation is thought to be regulated at a transcriptional level by the peroxisome proliferator-activated receptor alpha (PPAR-alpha). We proposed that obesity...

  4. Three-dimensional anisotropic adaptive filtering of projection data for noise reduction in cone beam CT

    Purpose: The combination of quickly rotating C-arm gantry with digital flat panel has enabled the acquisition of three-dimensional data (3D) in the interventional suite. However, image quality is still somewhat limited since the hardware has not been optimized for CT imaging. Adaptive anisotropic filtering has the ability to improve image quality by reducing the noise level and therewith the radiation dose without introducing noticeable blurring. By applying the filtering prior to 3D reconstruction, noise-induced streak artifacts are reduced as compared to processing in the image domain. Methods: 3D anisotropic adaptive filtering was used to process an ensemble of 2D x-ray views acquired along a circular trajectory around an object. After arranging the input data into a 3D space (2D projections + angle), the orientation of structures was estimated using a set of differently oriented filters. The resulting tensor representation of local orientation was utilized to control the anisotropic filtering. Low-pass filtering is applied only along structures to maintain high spatial frequency components perpendicular to these. The evaluation of the proposed algorithm includes numerical simulations, phantom experiments, and in-vivo data which were acquired using an AXIOM Artis dTA C-arm system (Siemens AG, Healthcare Sector, Forchheim, Germany). Spatial resolution and noise levels were compared with and without adaptive filtering. A human observer study was carried out to evaluate low-contrast detectability. Results: The adaptive anisotropic filtering algorithm was found to significantly improve low-contrast detectability by reducing the noise level by half (reduction of the standard deviation in certain areas from 74 to 30 HU). Virtually no degradation of high contrast spatial resolution was observed in the modulation transfer function (MTF) analysis. Although the algorithm is computationally intensive, hardware acceleration using Nvidia's CUDA Interface provided an 8.9-fold

  5. Response of benthic metabolism and nutrient cycling to reductions in wastewater loading to Boston Harbor, USA

    Tucker, Jane; Giblin, Anne E.; Hopkinson, Charles S.; Kelsey, Samuel W.; Howes, Brian L.

    2014-12-01

    We describe the long-term response of benthic metabolism in depositional sediments of Boston Harbor, MA, to large reductions in organic matter and nutrient loading. Although Boston Harbor received very high loadings of nutrients and solids it differs from many eutrophic estuaries in that severe hypoxia was prevented by strong tidal flushing. Our study was conducted for 9 years during which a series of improvements to sewage treatment were implemented, followed by 10 years after the culminating step in the clean-up, which was to divert all wastewater effluent offshore. Counter to expectations, sediment oxygen demand and nutrient effluxes initially increased at some stations, reaching some of the highest rates recorded in the literature, and were spatially and temporally quite variable. Early increases were attributed to macrofaunal effects, as sediments at some sites were rapidly colonized by tube-building amphipods, Ampelisca spp., which dominated a dense macrofaunal mat community. As reductions in loading progressed, however, mean rates in oxygen uptake and release of ammonium, nitrate, and phosphate all decreased. At the point of outfall diversion, rates and variability had already decreased substantially. By the end of the study, average oxygen uptake had decreased from 74 to 41 mmol m-2 d-1 and spatial and temporal variability had decreased. Similarly, nutrient fluxes were less than half the rates measured at the start of the project and also less variable. Other evidence of improved conditions included a decrease in the carbon content of sediments at most stations and higher Eh values at all stations, illustrating less reducing conditions. Denitrification also showed an overall decrease from the beginning to the end of the 19-year study, but was highest during the intermediate phases of the cleanup, reaching 9 mmol N m-2 d-1. At the end of the study denitrification averaged for all sites was 2.2 mmol N m-2 d-1, but when compared to current loadings, had become

  6. Sultr4;1 mutant seeds of Arabidopsis have an enhanced sulphate content and modified proteome suggesting metabolic adaptations to altered sulphate compartmentalization

    Belghazi Maya

    2010-04-01

    Full Text Available Abstract Background Sulphur is an essential macronutrient needed for the synthesis of many cellular components. Sulphur containing amino acids and stress response-related compounds, such as glutathione, are derived from reduction of root-absorbed sulphate. Sulphate distribution in cell compartments necessitates specific transport systems. The low-affinity sulphate transporters SULTR4;1 and SULTR4;2 have been localized to the vacuolar membrane, where they may facilitate sulphate efflux from the vacuole. Results In the present study, we demonstrated that the Sultr4;1 gene is expressed in developing Arabidopsis seeds to a level over 10-fold higher than the Sultr4;2 gene. A characterization of dry mature seeds from a Sultr4;1 T-DNA mutant revealed a higher sulphate content, implying a function for this transporter in developing seeds. A fine dissection of the Sultr4;1 seed proteome identified 29 spots whose abundance varied compared to wild-type. Specific metabolic features characteristic of an adaptive response were revealed, such as an up-accumulation of various proteins involved in sugar metabolism and in detoxification processes. Conclusions This study revealed a role for SULTR4;1 in determining sulphate content of mature Arabidopsis seeds. Moreover, the adaptive response of sultr4;1 mutant seeds as revealed by proteomics suggests a function of SULTR4;1 in redox homeostasis, a mechanism that has to be tightly controlled during development of orthodox seeds.

  7. Integrative Phosphoproteomics Links IL-23R Signaling with Metabolic Adaptation in Lymphocytes.

    Lochmatter, Corinne; Fischer, Roman; Charles, Philip D; Yu, Zhanru; Powrie, Fiona; Kessler, Benedikt M

    2016-01-01

    Interleukin (IL)-23 mediated signal transduction represents a major molecular mechanism underlying the pathology of inflammatory bowel disease, Crohn's disease and ulcerative colitis. In addition, emerging evidence supports the role of IL-23-driven Th17 cells in inflammation. Components of the IL-23 signaling pathway, such as IL-23R, JAK2 and STAT3, have been characterized, but elements unique to this network as compared to other interleukins have not been readily explored. In this study, we have undertaken an integrative phosphoproteomics approach to better characterise downstream signaling events. To this end, we performed and compared phosphopeptide and phosphoprotein enrichment methodologies after activation of T lymphocytes by IL-23. We demonstrate the complementary nature of the two phosphoenrichment approaches by maximizing the capture of phosphorylation events. A total of 8202 unique phosphopeptides, and 4317 unique proteins were identified, amongst which STAT3, PKM2, CDK6 and LASP-1 showed induction of specific phosphorylation not readily observed after IL-2 stimulation. Interestingly, quantitative analysis revealed predominant phosphorylation of pre-existing STAT3 nuclear subsets in addition to translocation of phosphorylated STAT3 within 30 min after IL-23 stimulation. After IL-23R activation, a small subset of PKM2 also translocates to the nucleus and may contribute to STAT3 phosphorylation, suggesting multiple cellular responses including metabolic adaptation. PMID:27080861

  8. Locomotor, cardiocirculatory and metabolic adaptations to training in Andalusian and Anglo-Arabian horses.

    Muñoz, A; Santisteban, R; Rubio, M D; Agüera, E I; Escribano, B M; Castejón, F M

    1999-02-01

    The effects of two training programmes in 20 Andalusian and 12 Anglo-Arabian horses were evaluated by an increasing intensity work test at velocities of 4, 5, 6, 7 and 8 m sec(-1). Heart rate was monitored and blood samples were drawn at rest and after each velocity to analyse packed cell volume, haemoglobin concentration, plasma lactate and potassium levels. Furthermore, the programmes were video-taped and stride length, duration and frequency, stance (restraint and propulsion), swing phase durations and stride vertical component were measured. The training protocol of the Andalusian horses produced significant decreases in the cardiovascular, haematological and metabolic responses to exercise. Locomotory training adaptation consisted of an increased stride frequency and a reduced stride length and vertical stride component. The last variable was the limiting factor of stride length both before and after training in the Andalusian horses. A different training protocol for show-jumping competition in Anglo-Arabian horses failed to show significant differences in the studied parameters to the work test, although an increase in stride length at velocities of over 6 m sec(-1) was observed. Stride vertical component did not have an effect on the physiological response to exercise, either before or after training. PMID:10088708

  9. Xenobiotic metabolizing enzyme gene polymorphisms predict response to lung volume reduction surgery

    DeMeo Dawn L

    2007-08-01

    Full Text Available Abstract Background In the National Emphysema Treatment Trial (NETT, marked variability in response to lung volume reduction surgery (LVRS was observed. We sought to identify genetic differences which may explain some of this variability. Methods In 203 subjects from the NETT Genetics Ancillary Study, four outcome measures were used to define response to LVRS at six months: modified BODE index, post-bronchodilator FEV1, maximum work achieved on a cardiopulmonary exercise test, and University of California, San Diego shortness of breath questionnaire. Sixty-four single nucleotide polymorphisms (SNPs were genotyped in five genes previously shown to be associated with chronic obstructive pulmonary disease susceptibility, exercise capacity, or emphysema distribution. Results A SNP upstream from glutathione S-transferase pi (GSTP1; p = 0.003 and a coding SNP in microsomal epoxide hydrolase (EPHX1; p = 0.02 were each associated with change in BODE score. These effects appeared to be strongest in patients in the non-upper lobe predominant, low exercise subgroup. A promoter SNP in EPHX1 was associated with change in BODE score (p = 0.008, with the strongest effects in patients with upper lobe predominant emphysema and low exercise capacity. One additional SNP in GSTP1 and three additional SNPs in EPHX1 were associated (p Conclusion Genetic variants in GSTP1 and EPHX1, two genes encoding xenobiotic metabolizing enzymes, were predictive of response to LVRS. These polymorphisms may identify patients most likely to benefit from LVRS.

  10. Radiation dose reduction in soft tissue neck CT using adaptive statistical iterative reconstruction (ASIR)

    Vachha, Behroze, E-mail: bvachha@partners.org [Neuroradiology Division, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114 (United States); Brodoefel, Harald; Wilcox, Carol; Hackney, David B.; Moonis, Gul [Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215 (United States)

    2013-12-01

    Purpose: To compare objective and subjective image quality in neck CT images acquired at different tube current–time products (275 mA s and 340 mA s) and reconstructed with filtered-back-projection (FBP) and adaptive statistical iterative reconstruction (ASIR). Materials and methods: HIPAA-compliant study with IRB approval and waiver of informed consent. 66 consecutive patients were randomly assigned to undergo contrast-enhanced neck CT at a standard tube-current–time-product (340 mA s; n = 33) or reduced tube-current–time-product (275 mA s, n = 33). Data sets were reconstructed with FBP and 2 levels (30%, 40%) of ASIR-FBP blending at 340 mA s and 275 mA s. Two neuroradiologists assessed subjective image quality in a blinded and randomized manner. Volume CT dose index (CTDIvol), dose-length-product (DLP), effective dose, and objective image noise were recorded. Signal-to-noise ratio (SNR) was computed as mean attenuation in a region of interest in the sternocleidomastoid muscle divided by image noise. Results: Compared with FBP, ASIR resulted in a reduction of image noise at both 340 mA s and 275 mA s. Reduction of tube current from 340 mA s to 275 mA s resulted in an increase in mean objective image noise (p = 0.02) and a decrease in SNR (p = 0.03) when images were reconstructed with FBP. However, when the 275 mA s images were reconstructed using ASIR, the mean objective image noise and SNR were similar to those of the standard 340 mA s CT images reconstructed with FBP (p > 0.05). Subjective image noise was ranked by both raters as either average or less-than-average irrespective of the tube current and iterative reconstruction technique. Conclusion: Adapting ASIR into neck CT protocols reduced effective dose by 17% without compromising image quality.

  11. Application of adaptive kinetic modelling for bias propagation reduction in direct 4D image reconstruction

    Parametric imaging in thoracic and abdominal PET can provide additional parameters more relevant to the pathophysiology of the system under study. However, dynamic data in the body are noisy due to the limiting counting statistics leading to suboptimal kinetic parameter estimates. Direct 4D image reconstruction algorithms can potentially improve kinetic parameter precision and accuracy in dynamic PET body imaging. However, construction of a common kinetic model is not always feasible and in contrast to post-reconstruction kinetic analysis, errors in poorly modelled regions may spatially propagate to regions which are well modelled. To reduce error propagation from erroneous model fits, we implement and evaluate a new approach to direct parameter estimation by incorporating a recently proposed kinetic modelling strategy within a direct 4D image reconstruction framework. The algorithm uses a secondary more general model to allow a less constrained model fit in regions where the kinetic model does not accurately describe the underlying kinetics. A portion of the residuals then is adaptively included back into the image whilst preserving the primary model characteristics in other well modelled regions using a penalty term that trades off the models. Using fully 4D simulations based on dynamic [15O]H2O datasets, we demonstrate reduction in propagation-related bias for all kinetic parameters. Under noisy conditions, reductions in bias due to propagation are obtained at the cost of increased noise, which in turn results in increased bias and variance of the kinetic parameters. This trade-off reflects the challenge of separating the residuals arising from poor kinetic modelling fits from the residuals arising purely from noise. Nonetheless, the overall root mean square error is reduced in most regions and parameters. Using the adaptive 4D image reconstruction improved model fits can be obtained in poorly modelled regions, leading to reduced errors potentially propagating

  12. A quantitative assay for reductive metabolism of a pesticide in fish using electrochemistry coupled with liquid chromatography tandem mass spectrometry.

    Bussy, Ugo; Chung-Davidson, Yu-Wen; Li, Ke; Li, Weiming

    2015-04-01

    This is the first study to use electrochemistry to generate a nitro reduction metabolite as a standard for a liquid chromatography-mass spectrometry-based quantitative assay. This approach is further used to quantify 3-trifluoromethyl-4-nitrophenol (TFM) reductive metabolism. TFM is a widely used pesticide for the population control of sea lamprey (Petromyzon marinus), an invasive species of the Laurentian Great Lakes. Three animal models, sea lamprey, lake sturgeon (Acipenser fulvescens), and rainbow trout (Oncorhynchus mykiss), were selected to evaluate TFM reductive metabolism because they have been known to show differential susceptibilities to TFM toxicity. Amino-TFM (aTFM; 3-trifluoromethyl-4-aminophenol) was the only reductive metabolite identified through liquid chromatography-high-resolution mass spectrometry screening of liver extracts incubated with TFM and was targeted for electrochemical synthesis. After synthesis and purification, aTFM was used to develop a quantitative assay of the reductive metabolism of TFM through liquid chromatography and tandem mass spectrometry. The concentrations of aTFM were measured from TFM-treated cellular fractions, including cytosolic, nuclear, membrane, and mitochondrial protein extracts. Sea lamprey extracts produced the highest concentrations (500 ng/mL) of aTFM. In addition, sea lamprey and sturgeon cytosolic extracts showed concentrations of aTFM substantially higher than those of rainbow trout. However, other fractions of lake sturgeon extracts tend to show aTFM concentrations similar to those of rainbow trout but not with sea lamprey. These data suggest that the level of reductive metabolism of TFM may be associated with the sensitivities of the animals to this particular pesticide. PMID:25730707

  13. Metabolism

    ... also influenced by body composition — people with more muscle and less fat generally have higher BMRs. previous continue Things That Can Go Wrong With Metabolism Most of the time your metabolism works effectively ...

  14. Metabolism

    2008-01-01

    2008255 Serum adiponectin level declines in the elderly with metabolic syndrome.WU Xiaoyan(吴晓琰),et al.Dept Geriatr,Huashan Hosp,Fudan UnivShanghai200040.Chin J Geriatr2008;27(3):164-167.Objective To investigate the correlation between ser-um adiponectin level and metabolic syndrome in the elderly·Methods Sixty-one subjects with metabolic syndrome and140age matched subjects without metabolic

  15. Adaptation of chondrocytes to low oxygen tension: relationship between hypoxia and cellular metabolism.

    Rajpurohit, R; Koch, C J; Tao, Z; Teixeira, C M; Shapiro, I M

    1996-08-01

    In endochondral bone, the growth cartilage is the site of rapid growth. Since the vascular supply to the cartilage is limited, it is widely assumed that cells of the cartilage are hypoxic and that limitations in the oxygen supply regulate the energetic state of the maturing cells. In this report, we evaluate the effects of oxygen tension on chondrocyte energy metabolism, thiol status, and expression of transcription elements, HIF and AP-1. Imposition of an hypoxic environment on cultured chondrocytes caused a proportional increase in glucose utilization and elevated levels of lactate synthesis. Although we observed a statistical increase in the activities of phosphofructokinase, pyruvate kinase, lactate dehydrogenase, and creatine kinase after exposure to lowered oxygen concentrations, the effect was small. The cultured cells exhibited a decreased utilization of glutamine, possibly due to down regulation of mitochondrial function and inhibition of oxidative deamination. With respect to total energy generation, we noted that these cells are quite capable of maintaining the energy charge of the cell at low oxygen tensions. Indeed, no changes in the absolute quantity of adenine nucleotides or the energy charge ratio was observed. Hypoxia caused a decrease in the glutathione content of cultured chondrocytes and a concomitant rise in cell and medium cysteine levels. It is likely that the fall in cell glutathione level is due to decreased synthesis of the tripeptide under reduced oxygen stress and the limited supply of glutamate. The observed rise in cellular and medium cysteine levels probably reflects an increase in the rate of degradation of glutathione and a decrease in synthesis of the peptide. To explore how cells transduce these metabolic effects, gel retardation assays were used to study chondrocyte HIF and AP-1 binding activities. Chondrocyte nuclear preparations bound an HIF-oligonucleotide; however, at low oxygen tensions, no increase in HIF binding was

  16. The correlation of sodium and potassium metabolism with the level of energy consumption in man during adaptation to heat

    Afanasyev, B. G.; Zhestovskiy, V. A.

    1978-01-01

    The sodium and potassium metabolism was studied in a thermal chamber at 35 deg and 80 percent relative humidity in 8 men for a period of 6 days. The control group (3 subjects) were outside of the chamber at a comfortable ambient temperature. The intracellular sodium and potassium metabolism were assessed based on their content in the erythrocytes. The finding was that during adaptation to heat, a considerable amount of sodium was excreted by the body in the sweat and urine (about 1/3 of the sodium content of the human body) as compared with its intake and the amount of potassium retained in the body. Changes in the concentration of sodium and potassium may serve as indexes of the state of adaptation processes during constant exposure to heat.

  17. Identification and analysis of uncertainty in disaster risk reduction and climate change adaptation in South and Southeast Asia

    Keur, van der Peter; Bers, van Caroline; Henriksen, Hans Jørgen; Nibanupudi, Hari Krishna; Yadav, Shobha; Wijaya, Rina; Subiyono, Andreas; Mukerjee, Nandan; Hausmann, Hans Jakob; Hare, Matt; Scheltinga, van Catharien Terwisscha; Pearn, Gregory; Jaspers, Fons

    2016-01-01

    This paper addresses the mainstreaming of uncertainty in Disaster Risk Reduction (DRR) and Climate Change Adaptation (CCA) using as a case South and Southeast Asia, a region highly vulnerable to a wide range of natural disasters. Improvements in the implementation of DRR and CCA at the community

  18. Biomimetic bluff body drag reduction by self-adaptive porous flaps

    Mazellier, Nicolas; Kourta, Azeddine

    2011-01-01

    The performances of an original passive control system based on a biomimetic approach are assessed by investigating the flow over a bluff-body. This control device consists in a couple of flaps made from the combination of a rigid plastic skeleton coated with a porous fabric mimicking the shaft and the vane of the bird's feathers, respectively. The sides of a square cylinder have been fitted with this system so as to enable the flaps to freely rotate around their leading edge. This feature allows the movable flaps to self-adapt to the flow conditions. Comparing both the uncontrolled and the controlled flow, a significant drag reduction (up to 22%) has been obtained over a broad range of Reynolds number. The investigation of the mean flow reveals a noticeable modification of the flow topology at large scale in the vicinity of the controlled cylinder accounting for the increase of the pressure base in comparison with the natural flow. Meanwhile, the study of the relative motion of both flaps points out that the...

  19. Metal artifact reduction in CT using tissue-class modeling and adaptive prefiltering

    High-density objects such as metal prostheses, surgical clips, or dental fillings generate streak-like artifacts in computed tomography images. We present a novel method for metal artifact reduction by in-painting missing information into the corrupted sinogram. The information is provided by a tissue-class model extracted from the distorted image. To this end the image is first adaptively filtered to reduce the noise content and to smooth out streak artifacts. Consecutively, the image is segmented into different material classes using a clustering algorithm. The corrupted and missing information in the original sinogram is completed using the forward projected information from the tissue-class model. The performance of the correction method is assessed on phantom images. Clinical images featuring a broad spectrum of metal artifacts are studied. Phantom and clinical studies show that metal artifacts, such as streaks, are significantly reduced and shadows in the image are eliminated. Furthermore, the novel approach improves detectability of organ contours. This can be of great relevance, for instance, in radiation therapy planning, where images affected by metal artifacts may lead to suboptimal treatment plans

  20. Multi-microphone adaptive noise reduction strategies for coordinated stimulation in bilateral cochlear implant devices.

    Kokkinakis, Kostas; Loizou, Philipos C

    2010-05-01

    Bilateral cochlear implant (BI-CI) recipients achieve high word recognition scores in quiet listening conditions. Still, there is a substantial drop in speech recognition performance when there is reverberation and more than one interferers. BI-CI users utilize information from just two directional microphones placed on opposite sides of the head in a so-called independent stimulation mode. To enhance the ability of BI-CI users to communicate in noise, the use of two computationally inexpensive multi-microphone adaptive noise reduction strategies exploiting information simultaneously collected by the microphones associated with two behind-the-ear (BTE) processors (one per ear) is proposed. To this end, as many as four microphones are employed (two omni-directional and two directional) in each of the two BTE processors (one per ear). In the proposed two-microphone binaural strategies, all four microphones (two behind each ear) are being used in a coordinated stimulation mode. The hypothesis is that such strategies combine spatial information from all microphones to form a better representation of the target than that made available with only a single input. Speech intelligibility is assessed in BI-CI listeners using IEEE sentences corrupted by up to three steady speech-shaped noise sources. Results indicate that multi-microphone strategies improve speech understanding in single- and multi-noise source scenarios. PMID:21117762

  1. Elevated dopamine concentration in light-adapted zebrafish retinas is correlated with increased dopamine synthesis and metabolism.

    Connaughton, Victoria P; Wetzell, Bradley; Arneson, Lynne S; DeLucia, Vittoria; Riley, Anthony L

    2015-10-01

    Probing zebrafish (Danio rerio) retinal cryostat sections, collected either 8 h into the light or dark cycle, with an antibody against tyrosine hydroxylase (TH) identified a single population of immunopositive cells in the inner retina. However, the observed labeling patterns were not identical in both sets of tissues - label intensity was brighter in light-adapted tissue. This difference was quantified by probing western blots of retinal homogenates with the same TH antibody, which showed that TH expression increased by 42% in light-adapted tissue. High-performance liquid chromatography with electrochemical detection revealed that the concentrations of both dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) are also elevated in light-adapted zebrafish retinal tissue. Dopamine levels increased by 14% and DOPAC levels increased by 25% when measured in retinal homogenates harvested during the light cycle. These results indicate that dopamine levels in zebrafish retina are significantly increased in light-adapted tissue. The increase in dopamine content is correlated with an increase in both TH and DOPAC, suggesting that changes in dopamine concentration are due to light-adaptive changes in the synthesis, release and metabolism of dopamine. Dopamine concentration is elevated in lighted-adapted zebrafish retinas. This increase is correlated with an increase in both tyrosine hydroxylase (TH) and DOPAC (3,4-dihydroxyphenylacetic acid), suggesting that changes in dopamine concentration are due to light-adaptive changes in the synthesis, release and metabolism of dopamine. This is applicable to studies examining retinal mutants, the role of dopamine in disease or visual system development. PMID:26212704

  2. Livelihoods and climate change : combining disaster risk reduction, natural resource management and climate change adaptation in a new approach to the reduction of vulnerability and poverty

    Burton, I.; Soussan, J.; Hammill, A.

    2003-07-01

    This paper provides a framework for researchers and policy-makers that are taking action on climate change adaptation. It presents innovative and sustainable ways to respond to the changing global climate. It focuses, in particular, on international research and policy initiatives on climate change, vulnerable communities and adaptation. The international and multi-disciplinary task force that put the framework together includes experts from the fields of disaster risk reduction, climate change, conservation and poverty reduction. The report emphasizes that successful climate change adaptation should be accomplished through actions that reduce the vulnerabilities of poor people and poor countries because people's livelihoods shape poverty and their ability to move out of poverty. The task force identifies the need to integrate a climate change adaptation approach based on the livelihoods of vulnerable communities in different parts of the world. The examples cited in this report include: (1) mangrove rehabilitation in Vietnam, (2) community-based rang eland rehabilitation for carbon sequestration in Sudan, (3) agroecological roots of resilience in Honduras, Nicaragua and Guatemala, and (4) watershed restoration and development in Maharashtra State, India. refs., figs.

  3. Livelihoods and climate change : combining disaster risk reduction, natural resource management and climate change adaptation in a new approach to the reduction of vulnerability and poverty

    This paper provides a framework for researchers and policy-makers that are taking action on climate change adaptation. It presents innovative and sustainable ways to respond to the changing global climate. It focuses, in particular, on international research and policy initiatives on climate change, vulnerable communities and adaptation. The international and multi-disciplinary task force that put the framework together includes experts from the fields of disaster risk reduction, climate change, conservation and poverty reduction. The report emphasizes that successful climate change adaptation should be accomplished through actions that reduce the vulnerabilities of poor people and poor countries because people's livelihoods shape poverty and their ability to move out of poverty. The task force identifies the need to integrate a climate change adaptation approach based on the livelihoods of vulnerable communities in different parts of the world. The examples cited in this report include: (1) mangrove rehabilitation in Vietnam, (2) community-based rang eland rehabilitation for carbon sequestration in Sudan, (3) agro-ecological roots of resilience in Honduras, Nicaragua and Guatemala, and (4) watershed restoration and development in Maharashtra State, India. refs., figs

  4. Exploring the molecular and metabolic factors contributing to the adaptation of maize seedlings to nitrate limitation

    Ashraf eEl-Kereamy

    2011-09-01

    Full Text Available Crop production on soils containing sub-optimal levels of nitrogen (N severely compromises yield potential. The development of plant varieties displaying high N use efficiency (NUE will optimize N fertilizer use and reduce the environmental damage caused by excess N application. Maize is one of the most important crops cultivated worldwide. Identification of the genotypes with an enhanced NUE in the field is both time and resource consuming and sometime is difficult due to the regulation in the biotechnology programs. Identification of traits associated with adaptation to N limitation at an early vegetative stage which could reflect NUE at maturity is in need. We developed a hydroponic growth system and used it to test two genotypes that were different in their NUE at maturity under N limitation. One genotype SRG-200 showed a higher NUE than the other genotype SRG-100 and we used its hybrid SRG-150 as a reference for NUE. A number of phenotypic, molecular and metabolic factors were tested using these three genetic lines at an early vegetative stage to determine which of these could be more indicative of predicting improved NUE at an early seedling stage. These include a transcriptional analysis which showed that the higher NUE in SRG-200 genotype is associated with higher transcript levels for the genes involved in nitrate transport, N assimilation and GS and that the SRG-200 genotype maintained higher sugar content in leaves. Those identified in this study could be useful indicators for selecting promising maize lines at early stages to help develop elite varieties showing an enhanced NUE.

  5. Metabolic adaptation of Ralstonia solanacearum during plant infection: a methionine biosynthesis case study.

    Laure Plener

    Full Text Available MetE and MetH are two distinct enzymes that catalyze a similar biochemical reaction during the last step of methionine biosynthesis, MetH being a cobalamin-dependent enzyme whereas MetE activity is cobalamin-independent. In this work, we show that the last step of methionine synthesis in the plant pathogen Ralstonia solanacearum is under the transcriptional control of the master pathogenicity regulator HrpG. This control is exerted essentially on metE expression through the intermediate regulator MetR. Expression of metE is strongly and specifically induced in the presence of plant cells in a hrpG- and metR-dependent manner. metE and metR mutants are not auxotrophic for methionine and not affected for growth inside the plant but produce significantly reduced disease symptoms on tomato whereas disruption of metH has no impact on pathogenicity. The finding that the pathogen preferentially induces metE expression rather than metH in the presence of plant cells is indicative of a probable metabolic adaptation to physiological host conditions since this induction of metE occurs in an environment in which cobalamin, the required co-factor for MetH, is absent. It also shows that MetE and MetH are not functionally redundant and are deployed during specific stages of the bacteria lifecycle, the expression of metE and metH being controlled by multiple and distinct signals.

  6. Comparative genome analysis reveals metabolic versatility and environmental adaptations of Sulfobacillus thermosulfidooxidans strain ST.

    Xue Guo

    Full Text Available The genus Sulfobacillus is a cohort of mildly thermophilic or thermotolerant acidophiles within the phylum Firmicutes and requires extremely acidic environments and hypersalinity for optimal growth. However, our understanding of them is still preliminary partly because few genome sequences are available. Here, the draft genome of Sulfobacillus thermosulfidooxidans strain ST was deciphered to obtain a comprehensive insight into the genetic content and to understand the cellular mechanisms necessary for its survival. Furthermore, the expressions of key genes related with iron and sulfur oxidation were verified by semi-quantitative RT-PCR analysis. The draft genome sequence of Sulfobacillus thermosulfidooxidans strain ST, which encodes 3225 predicted coding genes on a total length of 3,333,554 bp and a 48.35% G+C, revealed the high degree of heterogeneity with other Sulfobacillus species. The presence of numerous transposases, genomic islands and complete CRISPR/Cas defence systems testifies to its dynamic evolution consistent with the genome heterogeneity. As expected, S. thermosulfidooxidans encodes a suit of conserved enzymes required for the oxidation of inorganic sulfur compounds (ISCs. The model of sulfur oxidation in S. thermosulfidooxidans was proposed, which showed some different characteristics from the sulfur oxidation of Gram-negative A. ferrooxidans. Sulfur oxygenase reductase and heterodisulfide reductase were suggested to play important roles in the sulfur oxidation. Although the iron oxidation ability was observed, some key proteins cannot be identified in S. thermosulfidooxidans. Unexpectedly, a predicted sulfocyanin is proposed to transfer electrons in the iron oxidation. Furthermore, its carbon metabolism is rather flexible, can perform the transformation of pentose through the oxidative and non-oxidative pentose phosphate pathways and has the ability to take up small organic compounds. It encodes a multitude of heavy metal

  7. An Adaptive Management Approach for Summer Water Level Reductions on the Upper Mississippi River System

    Johnson, B.L.; Barko, J.W.; Clevenstine, R.; Davis, M.; Galat, D.L.; Lubinski, S.J.; Nestler, J.M.

    2010-01-01

    The primary purpose of this report is to provide an adaptive management approach for learning more about summer water level reductions (drawdowns) as a management tool, including where and how drawdowns can be applied most effectively within the Upper Mississippi River System. The report reviews previous drawdowns conducted within the system and provides specific recommendations for learning more about the lesser known effects of drawdowns and how the outcomes can be influenced by different implementation strategies and local conditions. The knowledge gained can be used by managers to determine how best to implement drawdowns in different parts of the UMRS to help achieve management goals. The information and recommendations contained in the report are derived from results of previous drawdown projects, insights from regional disciplinary experts, and the experience of the authors in experimental design, modeling, and monitoring. Modeling is a critical part of adaptive management and can involve conceptual models, simulation models, and empirical models. In this report we present conceptual models that express current understanding regarding functioning of the UMRS as related to drawdowns and highlight interactions among key ecological components of the system. The models were developed within the constraints of drawdown timing, magnitude (depth), and spatial differences in effects (longitudinal and lateral) with attention to ecological processes affected by drawdowns. With input from regional experts we focused on the responses of vegetation, fish, mussels, other invertebrates, and birds. The conceptual models reflect current understanding about relations and interactions among system components, the expected strength of those interactions, potential responses of system components to drawdowns, likelihood of the response occurring, and key uncertainties that limit our ability to make accurate predictions of effects (Table 1, Fig. 4-10). Based on this current

  8. Phylogeography, Salinity Adaptations and Metabolic Potential of the Candidate Division KB1 Bacteria Based on a Partial Single Cell Genome.

    Nigro, Lisa M; Hyde, Andrew S; MacGregor, Barbara J; Teske, Andreas

    2016-01-01

    Deep-sea hypersaline anoxic basins and other hypersaline environments contain abundant and diverse microbial life that has adapted to these extreme conditions. The bacterial Candidate Division KB1 represents one of several uncultured groups that have been consistently observed in hypersaline microbial diversity studies. Here we report the phylogeography of KB1, its phylogenetic relationships to Candidate Division OP1 Bacteria, and its potential metabolic and osmotic stress adaptations based on a partial single cell amplified genome of KB1 from Orca Basin, the largest hypersaline seafloor brine basin in the Gulf of Mexico. Our results are consistent with the hypothesis - previously developed based on (14)C incorporation experiments with mixed-species enrichments from Mediterranean seafloor brines - that KB1 has adapted its proteins to elevated intracellular salinity, but at the same time KB1 apparently imports glycine betaine; this compatible solute is potentially not limited to osmoregulation but could also serve as a carbon and energy source. PMID:27597842

  9. Metabolic Adaptations of Azospirillum brasilense to Oxygen Stress by Cell-to-Cell Clumping and Flocculation

    Bible, Amber N.; Khalsa-Moyers, Gurusahai K.; Mukherjee, Tanmoy; Green, Calvin S.; Mishra, Priyanka; Purcell, Alicia; Aksenova, Anastasia; Hurst, Gregory B.

    2015-01-01

    The ability of bacteria to monitor their metabolism and adjust their behavior accordingly is critical to maintain competitiveness in the environment. The motile microaerophilic bacterium Azospirillum brasilense navigates oxygen gradients by aerotaxis in order to locate low oxygen concentrations that can support metabolism. When cells are exposed to elevated levels of oxygen in their surroundings, motile A. brasilense cells implement an alternative response to aerotaxis and form transient clumps by cell-to-cell interactions. Clumping was suggested to represent a behavior protecting motile cells from transiently elevated levels of aeration. Using the proteomics of wild-type and mutant strains affected in the extent of their clumping abilities, we show that cell-to-cell clumping represents a metabolic scavenging strategy that likely prepares the cells for further metabolic stresses. Analysis of mutants affected in carbon or nitrogen metabolism confirmed this assumption. The metabolic changes experienced as clumping progresses prime cells for flocculation, a morphological and metabolic shift of cells triggered under elevated-aeration conditions and nitrogen limitation. The analysis of various mutants during clumping and flocculation characterized an ordered set of changes in cell envelope properties accompanying the metabolic changes. These data also identify clumping and early flocculation to be behaviors compatible with the expression of nitrogen fixation genes, despite the elevated-aeration conditions. Cell-to-cell clumping may thus license diazotrophy to microaerophilic A. brasilense cells under elevated oxygen conditions and prime them for long-term survival via flocculation if metabolic stress persists. PMID:26407887

  10. Metabolic adaptations of Azospirillum brasilense to oxygen stress by cell-to-cell clumping and flocculation.

    Bible, Amber N; Khalsa-Moyers, Gurusahai K; Mukherjee, Tanmoy; Green, Calvin S; Mishra, Priyanka; Purcell, Alicia; Aksenova, Anastasia; Hurst, Gregory B; Alexandre, Gladys

    2015-12-01

    The ability of bacteria to monitor their metabolism and adjust their behavior accordingly is critical to maintain competitiveness in the environment. The motile microaerophilic bacterium Azospirillum brasilense navigates oxygen gradients by aerotaxis in order to locate low oxygen concentrations that can support metabolism. When cells are exposed to elevated levels of oxygen in their surroundings, motile A. brasilense cells implement an alternative response to aerotaxis and form transient clumps by cell-to-cell interactions. Clumping was suggested to represent a behavior protecting motile cells from transiently elevated levels of aeration. Using the proteomics of wild-type and mutant strains affected in the extent of their clumping abilities, we show that cell-to-cell clumping represents a metabolic scavenging strategy that likely prepares the cells for further metabolic stresses. Analysis of mutants affected in carbon or nitrogen metabolism confirmed this assumption. The metabolic changes experienced as clumping progresses prime cells for flocculation, a morphological and metabolic shift of cells triggered under elevated-aeration conditions and nitrogen limitation. The analysis of various mutants during clumping and flocculation characterized an ordered set of changes in cell envelope properties accompanying the metabolic changes. These data also identify clumping and early flocculation to be behaviors compatible with the expression of nitrogen fixation genes, despite the elevated-aeration conditions. Cell-to-cell clumping may thus license diazotrophy to microaerophilic A. brasilense cells under elevated oxygen conditions and prime them for long-term survival via flocculation if metabolic stress persists. PMID:26407887

  11. Assessment of Disaster Risk Reduction and Climate Change Adaptation policy integration in Zambia

    Pilli-Sihvola, K.; Väätäinen-Chimpuku, S.

    2015-12-01

    Integration of Disaster Risk Management (DRM) and Climate Change Adaptation (CCA) policies, their implementation measures and the contribution of these to development has been gaining attention recently. Due to the shared objectives of CCA and particularly Disaster Risk Reduction (DRR), a component of DRM, their integration provides many benefits. At the implementation level, DRR and CCA are usually integrated. Policy integration, however, is often lacking. This study presents a novel analysis of the policy integration of DRR and CCA by 1) suggesting a definition for their integration at a general and further at horizontal and vertical levels, 2) using an analysis framework for policy integration cycle, which separates the policy formulation and implementation processes, and 3) applying these to a case study in Zambia. Moreover, the study identifies the key gaps in the integration process, obtains an understanding of identified key factors for creating an enabling environment for the integration, and provides recommendations for further progress. The study is based on a document analysis of the relevant DRM, climate change (CC), agriculture, forestry, water management and meteorology policy documents and Acts, and 21 semi-structured interviews with key stakeholders. Horizontal integration has occurred both ways, as the revised DRM policy draft has incorporated CCA, and the new CC policy draft has incorporated DRR. This is not necessarily an optimal strategy and unless carefully implemented, it may create pressure on institutional structures and duplication of efforts in the implementation. Much less vertical integration takes place, and where it does, no guidance on how potential goal conflicts with sectorial and development objectives ought to be handled. The objectives of the instruments show convergence. At the programme stage, the measures are fully integrated as they can be classified as robust CCA measures, providing benefits in the current and future

  12. Climate Change Adaptation and Climate Related Disaster Risk Reduction Strategies in Zimbabwe and Malawi

    Mubaya, C. P.; Ngepah, N.; Seyama, W.

    2015-12-01

    Climate Change Adaptation (CCA) and Disaster Risk Reduction (DRR) have similar aims and mutual benefits, and there is a very strong rationale for adopting a more integrated approach to these issues rather than analysing each of them as distinct from the other. One of the gaps that have been noted in this context is the lack of evidence in systematic integration of CCA and DRR in Southern Africa. In this regard, this study builds on understanding CCA and DRR policies from the perspectives of vulnerable groups- women and smallholder farmers, and conducts institutional and policy analysis of CCA and DRR in southern Africa, with specific focus on Malawi and Zimbabwe. Both quantitative and qualitative methodologies were employed to collect data for this study in the two countries. The analysis is centred on the conceptualization of DRR in the context of recovery time and CCA on livelihood changes. Findings of the study show that drought is no longer viewed as a hazard as it is a perennial and chronic occurrence in selected climate hotspots, with heightened intensity in certain identified years. Households are able to quickly recover from slow onset hazards such as droughts and dry spells more than they are able to recover from sudden onset floods, implying more capacity towards CCA than DRR. Government programmes and policies are also focused more on CCA than on DRR efforts that appear not to be a priority. Findings point towards female vulnerability from perceptions and practice where males tend to dominate where they are set to benefit from external assistance. We need to strengthen government capacity in implementation of DRR programmes, which is currently limited and development initiatives must deliberately target building the resilience of women.

  13. Two brothers with skewed thiopurine metabolism in ulcerative colitis treated successfully with allopurinol and mercaptopurine dose reduction.

    Hoentjen, Frank; Hanauer, Stephen B; de Boer, Nanne K; Rubin, David T

    2012-01-01

    Thiopurine therapy effectively maintains remission in inflammatory bowel disease. However, many patients are unable to achieve optimum benefits from azathioprine or 6-mercaptopurine because of undesirable metabolism related to high thiopurine methyltransferase (TPMT) activity characterized by hepatic transaminitis secondary to increased 6-methylmercaptopurine (6-MMP) production and reduced levels of therapeutic 6-thioguanine nucleotide (6-TGN). Allopurinol can optimize this skewed metabolism. We discuss two brothers who were both diagnosed with ulcerative colitis (UC). Their disease remained active despite oral and topical mesalamines. Steroids followed by 6-mercaptopurine (MP) were unsuccessfully introduced for both patients and both were found to have high 6-MMP and low 6-TGN levels, despite normal TMPT enzyme activity, accompanied by transaminitis. Allopurinol was introduced in combination with MP dose reduction. For both brothers addition of allopurinol was associated with successful remission and optimized MP metabolites. These siblings with active UC illustrate that skewed thiopurine metabolism may occur despite normal TPMT enzyme activity and can lead to adverse events in the absence of disease control. We confirm previous data showing that addition of allopurinol can reverse this skewed metabolism, and reduce both hepatotoxicity and disease activity, but we now also introduce the concept of a family history of preferential MP metabolism as a clue to effective management for other family members. PMID:22147254

  14. Elucidating the adaptation and temporal coordination of metabolic pathways using in-silico evolution

    Gottstein, W.; Müller, Stefan; Herzel, H.; Steuer, Ralf

    2014-01-01

    Roč. 117, mar (2014), s. 68-76. ISSN 0303-2647 R&D Projects: GA MŠk(CZ) EE2.3.20.0256 Institutional support: RVO:67179843 Keywords : evolutionary algorithms * flux-balance analysis * metabolic oscillations * metabolism * systems biology Subject RIV: EI - Biotechnology ; Bionics Impact factor: 1.548, year: 2014

  15. Pseudo-transition Analysis Identifies the Key Regulators of Dynamic Metabolic Adaptations from Steady-State Data.

    Gerosa, Luca; Haverkorn van Rijsewijk, Bart R B; Christodoulou, Dimitris; Kochanowski, Karl; Schmidt, Thomas S B; Noor, Elad; Sauer, Uwe

    2015-10-28

    Hundreds of molecular-level changes within central metabolism allow a cell to adapt to the changing environment. A primary challenge in cell physiology is to identify which of these molecular-level changes are active regulatory events. Here, we introduce pseudo-transition analysis, an approach that uses multiple steady-state observations of (13)C-resolved fluxes, metabolites, and transcripts to infer which regulatory events drive metabolic adaptations following environmental transitions. Pseudo-transition analysis recapitulates known biology and identifies an unexpectedly sparse, transition-dependent regulatory landscape: typically a handful of regulatory events drive adaptation between carbon sources, with transcription mainly regulating TCA cycle flux and reactants regulating EMP pathway flux. We verify these observations using time-resolved measurements of the diauxic shift, demonstrating that some dynamic transitions can be approximated as monotonic shifts between steady-state extremes. Overall, we show that pseudo-transition analysis can explore the vast regulatory landscape of dynamic transitions using relatively few steady-state data, thereby guiding time-consuming, hypothesis-driven molecular validations. PMID:27136056

  16. Review Article: "Adaptive governance and resilience: the role of multi-stakeholder platforms in disaster risk reduction"

    R. Djalante

    2012-01-01

    Disaster impacts are more frequent, deadly and costly. The social and environmental consequences are increasingly complex and intertwined. Systematic as well as innovated strategies are needed to manage the impacts. Disaster Risk Reduction (DRR) is a systematic approach to manage disaster risks while adaptive governance (AG) is suggested as an alternative approach for governing complex problems such as disasters. The author proposes that the AG can be practicalised through a...

  17. Review Article: "Adaptive governance and resilience: the role of multi-stakeholder platforms in disaster risk reduction"

    R. Djalante

    2012-01-01

    Disaster impacts are more frequent, deadly and costly. The social and environmental consequences are increasingly complex and intertwined. Systematic as well as innovated strategies are needed to manage the impacts. Disaster Risk Reduction (DRR) is a systematic approach to manage disaster risks while adaptive governance (AG) is suggested as an alternative approach for governing complex problems such as disasters. The author proposes that the AG can be practicalised through a mechanism of mult...

  18. Metabolic Symbiosis Enables Adaptive Resistance to Anti-angiogenic Therapy that Is Dependent on mTOR Signaling.

    Allen, Elizabeth; Miéville, Pascal; Warren, Carmen M; Saghafinia, Sadegh; Li, Leanne; Peng, Mei-Wen; Hanahan, Douglas

    2016-05-10

    Therapeutic targeting of tumor angiogenesis with VEGF inhibitors results in demonstrable, but transitory efficacy in certain human tumors and mouse models of cancer, limited by unconventional forms of adaptive/evasive resistance. In one such mouse model, potent angiogenesis inhibitors elicit compartmental reorganization of cancer cells around remaining blood vessels. The glucose and lactate transporters GLUT1 and MCT4 are induced in distal hypoxic cells in a HIF1α-dependent fashion, indicative of glycolysis. Tumor cells proximal to blood vessels instead express the lactate transporter MCT1, and p-S6, the latter reflecting mTOR signaling. Normoxic cancer cells import and metabolize lactate, resulting in upregulation of mTOR signaling via glutamine metabolism enhanced by lactate catabolism. Thus, metabolic symbiosis is established in the face of angiogenesis inhibition, whereby hypoxic cancer cells import glucose and export lactate, while normoxic cells import and catabolize lactate. mTOR signaling inhibition disrupts this metabolic symbiosis, associated with upregulation of the glucose transporter GLUT2. PMID:27134166

  19. Dynamical feedback between circadian clock and sucrose availability explains adaptive response of starch metabolism to various photoperiods

    Francois Gabriel Feugier

    2013-01-01

    Full Text Available Plants deal with resource management during all their life. During the day they feed on photosynthetic carbon, sucrose, while storing a part into starch for night use. Careful control of carbon partitioning, starch degradation and sucrose export rates is crucial to avoid carbon starvation, insuring optimal growth whatever the photoperiod. Efficient regulation of these key metabolic rates can give an evolutionary advantage to plants. Here we propose a model of adaptive starch metabolism in response to various photoperiods. We assume the three key metabolic rates to be circadian regulated in leaves and that their phases of oscillations are shifted in response to sucrose starvation. We performed gradient descents for various photoperiod conditions to find the corresponding optimal sets of phase shifts that minimize starvation. Results at convergence were all consistent with experimental data: i diurnal starch profile showed linear increase during the day and linear decrease at night; ii shorter photoperiod tended to increase starch synthesis speed while decreasing its degradation speed during the longer night; iii sudden early dusk showed slower starch degradation during the longer night. Profiles that best explained observations corresponded to circadian regulation of all rates. This theoretical study would establish a framework for future research on feedback between starch metabolism and circadian clock as well as plant productivity.

  20. FGF21 as a Stress Hormone: The Roles of FGF21 in Stress Adaptation and the Treatment of Metabolic Diseases

    Kook Hwan Kim

    2014-08-01

    Full Text Available Fibroblast growth factor 21 (FGF21 is an endocrine hormone that is primarily expressed in the liver and exerts beneficial effects on obesity and related metabolic diseases. In addition to its remarkable pharmacologic actions, the physiological roles of FGF21 include the maintenance of energy homeostasis in the body in conditions of metabolic or environmental stress. The expression of FGF21 is induced in multiple organs in response to diverse physiological or pathological stressors, such as starvation, nutrient excess, autophagy deficiency, mitochondrial stress, exercise, and cold exposure. Thus, the FGF21 induction caused by stress plays an important role in adaptive response to these stimuli. Here, we highlight our current understanding of the functional importance of the induction of FGF21 by diverse stressors as a feedback mechanism that prevents excessive stress.

  1. Metabolism

    ... a particular food provides to the body. A chocolate bar has more calories than an apple, so ... More Common in People With Type 1 Diabetes Metabolic Syndrome Your Child's Weight Healthy Eating Endocrine System Blood ...

  2. Metabolic Adaptations of Azospirillum brasilense to Oxygen Stress by Cell-to-Cell Clumping and Flocculation

    Bible, Amber N.; Khalsa-Moyers, Gurusahai K.; Mukherjee, Tanmoy; Green, Calvin S.; Mishra, Priyanka; Purcell, Alicia; Aksenova, Anastasia; Gregory B Hurst; Alexandre, Gladys

    2015-01-01

    The ability of bacteria to monitor their metabolism and adjust their behavior accordingly is critical to maintain competitiveness in the environment. The motile microaerophilic bacterium Azospirillum brasilense navigates oxygen gradients by aerotaxis in order to locate low oxygen concentrations that can support metabolism. When cells are exposed to elevated levels of oxygen in their surroundings, motile A. brasilense cells implement an alternative response to aerotaxis and form transient clum...

  3. Adaptation of the symbiotic Mesorhizobium-chickpea relationship to phosphate deficiency relies on reprogramming of whole-plant metabolism.

    Nasr Esfahani, Maryam; Kusano, Miyako; Nguyen, Kien Huu; Watanabe, Yasuko; Ha, Chien Van; Saito, Kazuki; Sulieman, Saad; Herrera-Estrella, Luis; Tran, L S

    2016-08-01

    Low inorganic phosphate (Pi) availability is a major constraint for efficient nitrogen fixation in legumes, including chickpea. To elucidate the mechanisms involved in nodule acclimation to low Pi availability, two Mesorhizobium-chickpea associations exhibiting differential symbiotic performances, Mesorhizobium ciceri CP-31 (McCP-31)-chickpea and Mesorhizobium mediterranum SWRI9 (MmSWRI9)-chickpea, were comprehensively studied under both control and low Pi conditions. MmSWRI9-chickpea showed a lower symbiotic efficiency under low Pi availability than McCP-31-chickpea as evidenced by reduced growth parameters and down-regulation of nifD and nifK These differences can be attributed to decline in Pi level in MmSWRI9-induced nodules under low Pi stress, which coincided with up-regulation of several key Pi starvation-responsive genes, and accumulation of asparagine in nodules and the levels of identified amino acids in Pi-deficient leaves of MmSWRI9-inoculated plants exceeding the shoot nitrogen requirement during Pi starvation, indicative of nitrogen feedback inhibition. Conversely, Pi levels increased in nodules of Pi-stressed McCP-31-inoculated plants, because these plants evolved various metabolic and biochemical strategies to maintain nodular Pi homeostasis under Pi deficiency. These adaptations involve the activation of alternative pathways of carbon metabolism, enhanced production and exudation of organic acids from roots into the rhizosphere, and the ability to protect nodule metabolism against Pi deficiency-induced oxidative stress. Collectively, the adaptation of symbiotic efficiency under Pi deficiency resulted from highly coordinated processes with an extensive reprogramming of whole-plant metabolism. The findings of this study will enable us to design effective breeding and genetic engineering strategies to enhance symbiotic efficiency in legume crops. PMID:27450089

  4. Disruption of the acyl-coa binding protein gene delays hepatic adaptation to metabolic changes at weaning

    Neess, Ditte; Bloksgaard, Maria; Sørensen, Signe Bek; Marcher, Ann-Britt; Elle, Ida C; Helledie, Torben; Due, Marianne; Pagmantidis, Vasileios; Finsen, Bente; Wilbertz, Johannes; Kruhoeffer, Mogens; Faergeman, Nils; Mandrup, Susanne

    2011-01-01

    , little is known about the in vivo function in mammalian cells. We have generated mice with targeted disruption of ACBP (ACBP-/-). These mice are viable and fertile and develop normally. However, around weaning the ACBP-/- mice go through a crisis with overall weakness, and a slightly decreased growth...... rate. Using microarray analysis we show that the liver of ACBP-/- mice display a significantly delayed adaptation to weaning with late induction of target genes of the sterol regulatory element binding protein (SREBP) family. As a result, hepatic de novo cholesterogenesis is decreased at weaning. The...... delayed induction of SREBP target genes around weaning is caused by a compromised processing and decreased expression of SREBP precursors leading to reduced binding of SREBP to target sites in chromatin. In conclusion, lack of ACBP interferes with the normal metabolic adaptation to weaning and leads to...

  5. Flux analysis of central metabolic pathways in Geobactermetallireducens during reduction of solubleFe(III)-NTA

    Tang, Yinjie J.; Chakraborty, Romy; Garcia-Martin, Hector; Chu,Jeannie; Hazen, Terry C.; Keasling, Jay D.

    2007-01-01

    We analyzed the carbon fluxes in the central metabolism ofGeobacter metallireducens strain GS-15 using 13C isotopomer modeling.Acetate labeled in the 1st or 2nd position was the sole carbon source,and Fe-NTA was the sole terminal electron acceptor. The measured labeledacetate uptake rate was 21 mmol/gdw/h in the exponential growth phase.The resulting isotope labeling pattern of amino acids allowed an accuratedetermination of the in vivo global metabolic reaction rates (fluxes)through the central metabolic pathways using a computational isotopomermodel. The tracer experiments showed that G. metallireducens containedcomplete biosynthesis pathways for essential metabolism, and this strainmight also have an unusual isoleucine biosynthesis route (usingacetyl-CoA and pyruvate as the precursors). The model indicated that over90 percent of the acetate was completely oxidized to CO2 via a completetricarboxylic acid (TCA) cycle while reducing iron. Pyruvate carboxylaseand phosphoenolpyruvate carboxykinase were present under theseconditions, but enzymes in the glyoxylate shunt and malic enzyme wereabsent. Gluconeogenesis and the pentose phosphate pathway were mainlyemployed for biosynthesis and accounted for less than 3 percent of totalcarbon consumption. The model also indicated surprisingly highreversibility in the reaction between oxoglutarate and succinate. Thisstep operates close to the thermodynamic equilibrium possibly becausesuccinate is synthesized via a transferase reaction, and the conversionof oxoglutarate to succinate is a rate limiting step for carbonmetabolism. These findings enable a better understanding of therelationship between genome annotation and extant metabolic pathways inG. metallireducens.

  6. Marked reduction of cerebral oxygen metabolism in patients with advanced cirrhosis

    Regional cerebral blood flow (rCBF), cerebral metabolic rate of oxygen (rCMRO2), and oxygen extraction fraction (rOEF) were measured using positron emission tomography (PET) in four patients with cirrhosis (two males and two females, aged 57 to 69 years) in comparison with those in five age matched controls with previous transient global amnesia. PET studies were carried out when the patients were fully alert and oriented after the episodes of encephalopathy. In the patients, rCBF tended to be lower, while rCMRO2 was significantly lowered in almost all hemisphere cortices, more markedly in the frontal cortex. Our results suggest that the brain oxygen metabolism is diffusely impaired in patients with advanced cirrhosis, and the frontal cortex seems to be more susceptible to the systemic metabolic derangements induced by chronic liver disease. (author)

  7. Marked reduction of cerebral oxygen metabolism in patients with advanced cirrhosis; A positron emission tomography study

    Kawatoko, Toshiharu; Murai, Koichiro; Ibayashi, Setsurou; Tsuji, Hiroshi; Nomiyama, Kensuke; Sadoshima, Seizo; Eujishima, Masatoshi; Kuwabara, Yasuo; Ichiya, Yuichi (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine)

    1992-01-01

    Regional cerebral blood flow (rCBF), cerebral metabolic rate of oxygen (rCMRO{sub 2}), and oxygen extraction fraction (rOEF) were measured using positron emission tomography (PET) in four patients with cirrhosis (two males and two females, aged 57 to 69 years) in comparison with those in five age matched controls with previous transient global amnesia. PET studies were carried out when the patients were fully alert and oriented after the episodes of encephalopathy. In the patients, rCBF tended to be lower, while rCMRO{sub 2} was significantly lowered in almost all hemisphere cortices, more markedly in the frontal cortex. Our results suggest that the brain oxygen metabolism is diffusely impaired in patients with advanced cirrhosis, and the frontal cortex seems to be more susceptible to the systemic metabolic derangements induced by chronic liver disease. (author).

  8. Using tropical forest ecosystem goods and services for planning climate change adaptation with implications for food security and poverty reduction

    Johnson Nkem

    2007-12-01

    Full Text Available Tropical forest ecosystems represent a common heritage with livelihood portfolios shared by a great majority of people especially in developing countries but are now threatened by climate change. In spite of their contribution to poverty alleviation and food security, and also for climate change responses (adaptation and mitigation especially through the market-incentive schemes (CDM of the Kyoto Protocol forests are still hardly integrated into national planning processes aimed at addressing any of these national development challenges. This is evident in some of the national documents of some developing countries such as the Poverty Reduction Strategy Paper (PRSP to the World Bank, and the First National Communication to UNFCCC. This paper presents some preliminary outcomes of the Tropical Forests and Climate Change Adaptation (TroFCCA project of the Center for International Forestry Research (CIFOR whose overall mission is to underscore the importance of tropical forests for livelihood adaptation to climate change and mainstreaming adaptation into national development processes. The paper also highlights TroFCCA’s approach in engaging stakeholders from the onset in setting the agenda with the identification and prioritization of forest-based sectors as the entry point in the process of assessing the vulnerability to climate change and developing adaptation strategies for these selected development sectors. This is a highly crucial area with great policy implications. Planning with ecosystem goods and services seems to emerge as a prospective approach to demonstrate to policymakers the potential of forest ecosystems for livelihood adaptation to climate change which also enhances the opportunity for achieving food security and community resilience to poverty. TroFCCA’s approach in engaging stakeholders at the onset in defining their perception of ecosystem goods and services by virtue of their importance to household livelihoods and their

  9. Adaptive Model Predictive Control of Diesel Engine Selective Catalytic Reduction (SCR) Systems

    McKinley, Thomas L.

    2009-01-01

    Selective catalytic reduction or SCR is coming into worldwide use for diesel engine emissions reduction for on- and off-highway vehicles. These applications are characterized by broad operating range as well as rapid and unpredictable changes in operating conditions. Significant nonlinearity, input and output constraints, and stringent performance…

  10. Transcriptome analysis of Salicornia europaea under saline conditions revealed the adaptive primary metabolic pathways as early events to facilitate salt adaptation.

    Pengxiang Fan

    Full Text Available BACKGROUND: Halophytes such as Salicornia europaea have evolved to exhibit unique mechanisms controlled by complex networks and regulated by numerous genes and interactions to adapt to habitats with high salinity. However, these mechanisms remain unknown. METHODS: To investigate the mechanism by which halophytes tolerate salt based on changes in the whole transcriptome, we performed transcriptome sequencing and functional annotation by database search. Using the unigene database, we conducted digital gene expression analysis of S. europaea at various time points after these materials were treated with NaCl. We also quantified ion uptakes. Gene functional enrichment analysis was performed to determine the important pathways involved in this process. RESULTS: A total of 57,151 unigenes with lengths of >300 bp were assembled, in which 57.5% of these unigenes were functionally annotated. Differentially expressed genes indicated that cell wall metabolism and lignin biosynthetic pathways were significantly enriched in S. europaea to promote the development of the xylem under saline conditions. This result is consistent with the increase in sodium uptake as ions pass through the xylem. Given that PSII efficiency remained unaltered, salt treatment activated the expression of electron transfer-related genes encoded by the chloroplast chromosome. Chlorophyll biosynthesis was also inhibited, indicating the energy-efficient state of the electron transfer system of S. europaea. CONCLUSIONS: The key function of adjusting important primary metabolic pathways in salt adaption was identified by analyzing the changes in the transcriptome of S. europaea. These pathways could involve unique salt tolerance mechanisms in halophytes. This study also provided information as the basis of future investigations on salt response genes in S. europaea. Ample gene resources were also provided to improve the genes responsible for the salt tolerance ability of crops.

  11. A Shape Memory Polymer Dialysis Needle Adapter for the Reduction of Hemodynamic Stress within Arteriovenous Grafts

    Ortega, J M; Small, W; Wilson, T S; Benett, W; Loge, J; Maitland, D J

    2006-08-16

    A deployable, shape memory polymer adapter is investigated for reducing the hemodynamic stress caused by a dialysis needle flow within an arteriovenous graft. Computational fluid dynamics simulations of dialysis sessions with and without the adapter demonstrate that the adapter provides a significant decrease in the wall shear stress. In vitro flow visualization measurements are made within a graft model following delivery and actuation of a prototype shape memory polymer adapter. Vascular access complications resulting from arteriovenous (AV) graft failures account for over $1 billion per year in the health care costs of dialysis patients in the U.S.[1] The primary mode of failure of arteriovenous fistulas (AVF's) and polytetrafluoroethylene (PTFE) grafts is the development of intimal hyperplasia (IH) and the subsequent formation of stenotic lesions, resulting in a graft flow decline. The hemodynamic stresses arising within AVF's and PTFE grafts play an important role in the pathogenesis of IH. Studies have shown that vascular damage can occur in regions where there is flow separation, oscillation, or extreme values of wall shear stress (WSS).[2] Nevaril et al.[3] show that exposure of red blood cells to WSS's on the order of 1500 dynes/cm2 can result in hemolysis. Hemodynamic stress from dialysis needle flow has recently been investigated for the role it plays in graft failure. Using laser Doppler velocimetry measurements, Unnikrishnan et al.[4] show that turbulence intensities are 5-6 times greater in the AV flow when the needle flow is present and that increased levels of turbulence exist for approximately 7-8cm downstream of the needle. Since the AVF or PTFE graft is exposed to these high levels of hemodynamic stress several hours each week during dialysis sessions, it is quite possible that needle flow is an important contributor to vascular access occlusion.[4] We present a method for reducing the hemodynamic stress in an AV graft by tailoring

  12. Reduction in hepatic drug metabolizing CYP3A4 activities caused by P450 oxidoreductase mutations identified in patients with disordered steroid metabolism

    Flueck, Christa E.; Mullis, Primus E. [Pediatric Endocrinology, Diabetology and Metabolism, Department of Clinical Research, University of Bern, Tiefenaustrasse 120c, CH 3004 Bern (Switzerland); Pandey, Amit V., E-mail: amit@pandeylab.org [Pediatric Endocrinology, Diabetology and Metabolism, Department of Clinical Research, University of Bern, Tiefenaustrasse 120c, CH 3004 Bern (Switzerland)

    2010-10-08

    Research highlights: {yields} Cytochrome P450 3A4 (CYP3A4), metabolizes 50% of drugs in clinical use and requires NADPH-P450 reductase (POR). {yields} Mutations in human POR cause congenital adrenal hyperplasia from diminished activities of steroid metabolizing P450s. {yields} We are reporting that mutations in POR may reduce CYP3A4 activity. {yields} POR mutants Y181D, A457H, Y459H, V492E and R616X lost 99%, while A287P, C569Y and V608F lost 60-85% CYP3A4 activity. {yields} Reduction of CYP3A4 activity may cause increased risk of drug toxicities/adverse drug reactions in patients with POR mutations. -- Abstract: Cytochrome P450 3A4 (CYP3A4), the major P450 present in human liver metabolizes approximately half the drugs in clinical use and requires electrons supplied from NADPH through NADPH-P450 reductase (POR, CPR). Mutations in human POR cause a rare form of congenital adrenal hyperplasia from diminished activities of steroid metabolizing P450s. In this study we examined the effect of mutations in POR on CYP3A4 activity. We used purified preparations of wild type and mutant human POR and in vitro reconstitution with purified CYP3A4 to perform kinetic studies. We are reporting that mutations in POR identified in patients with disordered steroidogenesis/Antley-Bixler syndrome (ABS) may reduce CYP3A4 activity, potentially affecting drug metabolism in individuals carrying mutant POR alleles. POR mutants Y181D, A457H, Y459H, V492E and R616X had more than 99% loss of CYP3A4 activity, while POR mutations A287P, C569Y and V608F lost 60-85% activity. Loss of CYP3A4 activity may result in increased risk of drug toxicities and adverse drug reactions in patients with POR mutations.

  13. Reduction in hepatic drug metabolizing CYP3A4 activities caused by P450 oxidoreductase mutations identified in patients with disordered steroid metabolism

    Research highlights: → Cytochrome P450 3A4 (CYP3A4), metabolizes 50% of drugs in clinical use and requires NADPH-P450 reductase (POR). → Mutations in human POR cause congenital adrenal hyperplasia from diminished activities of steroid metabolizing P450s. → We are reporting that mutations in POR may reduce CYP3A4 activity. → POR mutants Y181D, A457H, Y459H, V492E and R616X lost 99%, while A287P, C569Y and V608F lost 60-85% CYP3A4 activity. → Reduction of CYP3A4 activity may cause increased risk of drug toxicities/adverse drug reactions in patients with POR mutations. -- Abstract: Cytochrome P450 3A4 (CYP3A4), the major P450 present in human liver metabolizes approximately half the drugs in clinical use and requires electrons supplied from NADPH through NADPH-P450 reductase (POR, CPR). Mutations in human POR cause a rare form of congenital adrenal hyperplasia from diminished activities of steroid metabolizing P450s. In this study we examined the effect of mutations in POR on CYP3A4 activity. We used purified preparations of wild type and mutant human POR and in vitro reconstitution with purified CYP3A4 to perform kinetic studies. We are reporting that mutations in POR identified in patients with disordered steroidogenesis/Antley-Bixler syndrome (ABS) may reduce CYP3A4 activity, potentially affecting drug metabolism in individuals carrying mutant POR alleles. POR mutants Y181D, A457H, Y459H, V492E and R616X had more than 99% loss of CYP3A4 activity, while POR mutations A287P, C569Y and V608F lost 60-85% activity. Loss of CYP3A4 activity may result in increased risk of drug toxicities and adverse drug reactions in patients with POR mutations.

  14. A Cardiovascular Risk Reduction Program for American Indians with Metabolic Syndrome: The Balance Study

    Lee, Elisa T.; Jobe, Jared B.; Yeh, Jeunliang; Ali, Tauqeer; Rhoades, Everett R.; Knehans, Allen W.; Willis, Diane J.; Johnson, Melanie R.; Zhang, Ying; Poolaw, Bryce; Rogers, Billy

    2012-01-01

    The Balance Study is a randomized controlled trial designed to reduce cardiovascular disease (CVD) risk in 200 American Indian (AI) participants with metabolic syndrome who reside in southwestern Oklahoma. Major risk factors targeted include weight, diet, and physical activity. Participants are assigned randomly to one of two groups, a guided or a…

  15. Reduction of Active Power Loss byUsing Adaptive Cat Swarm Optimization

    Kanagasabai Lenin

    2014-08-01

    Full Text Available This paper presents, an Adaptive Cat Swarm Optimization (ACSO for solving reactive power dispatch problem. Cat Swarm Optimization (CSO is one of the new-fangled swarm intelligence algorithms for finding the most excellent global solution. Because of complication, sometimes conventional CSO takes a lengthy time to converge and cannot attain the precise solution. For solving reactive power dispatch problem and to improve the convergence accuracy level, we propose a new adaptive CSO namely ‘Adaptive Cat Swarm Optimization’ (ACSO. First, we take account of a new-fangled adaptive inertia weight to velocity equation and then employ an adaptive acceleration coefficient. Second, by utilizing the information of two previous or next dimensions and applying a new-fangled factor, we attain to a new position update equation composing the average of position and velocity information. The projected ACSO has been tested on standard IEEE 57 bus test system and simulation results shows clearly about the high-quality performance of the planned algorithm in tumbling the real power loss.

  16. Differential metabolic and endocrine adaptations in llamas, sheep, and goats fed high- and low-protein grass-based diets.

    Kiani, A; Alstrup, L; Nielsen, M O

    2015-10-01

    This study aimed to elucidate whether distinct endocrine and metabolic adaptations provide llamas superior ability to adapt to low protein content grass-based diets as compared with the true ruminants. Eighteen adult, nonpregnant females (6 llamas, 6 goats, and 6 sheep) were fed either green grass hay with (HP) or grass seed straw (LP) in a cross-over design experiment over 2 periods of 21 d. Blood samples were taken on day 21 in each period at -30, 60, 150, and 240 min after feeding the morning meal and analyzed for plasma contents of glucose, triglyceride, nonesterified fatty acids, β-hydroxy butyrate (BOHB), urea, creatinine, insulin, and leptin. Results showed that llamas vs sheep and goats had higher plasma concentrations of glucose (7.1 vs 3.5 and 3.6 ± 0.18 mmol/L), creatinine (209 vs 110 and 103 ± 10 μmol/L), and urea (6.7 vs 5.6 and 4.9 ± 0.5 mmol/L) but lower leptin (0.33 vs 1.49 and 1.05 ± 0.1 ng/mL) and BOHB (0.05 vs 0.26 and 0.12 ± 0.02 mmol/L), respectively. BOHB in llamas was extremely low for a ruminating animal. Llamas showed that hyperglycemia coexisted with hyperinsulinemia (in general on the HP diet; postprandially on the LP diet). Llamas were clearly hypercreatinemic compared with the true ruminants, which became further exacerbated on the LP diet, where they also sustained plasma urea at markedly higher concentrations. However, llamas had markedly lower leptin concentrations than the true ruminants. In conclusion, llamas appear to have an intrinsic insulin resistant phenotype. Augmentation of creatinine and sustenance of elevated plasma urea concentrations in llamas when fed the LP diet must reflect distinct metabolic adaptations of intermediary protein and/or nitrogen metabolism, not observed in the true ruminants. These features can contribute to explain lower metabolic rates in llamas compared with the true ruminants, which must improve the chances of survival on low protein content diets. PMID:26073222

  17. Cardiac dose reduction with breathing adapted radiotherapy using self respiration monitoring system for left-sided breast cancer

    To quantify the cardiac dose reduction during breathing adapted radiotherapy using Real-time Position Management (RPM) system in the treatment of left-sided breast cancer. Twenty-two patients with left-sided breast cancer underwent CT scans during breathing maneuvers including free breathing (FB), deep inspiration breath-hold (DIBH), and end inspiration breath-hold (EIBH). The RPM system was used to monitor respiratory motion, and the in-house self respiration monitoring (SRM) system was used for visual feedback. For each scan, treatment plans were generated and dosimetric parameters from DIBH and EIBH plans were compared to those of FB plans. All patients completed CT scans with different breathing maneuvers. When compared with FB plans, DIBH plans demonstrated significant reductions in irradiated heart volume and the heart V25, with the relative reduction of 71% and 70%, respectively (p < 0.001). EIBH plans also resulted in significantly smaller irradiated heart volume and lower heart V25 than FB plans, with the relative reduction of 39% and 37%, respectively (p = 0.002). Despite of significant expansion of lung volume using inspiration breath-hold, there were no significant differences in left lung V25 among the three plans. In comparison with FB, both DIBH and EIBH plans demonstrated a significant reduction of radiation dose to the heart. In the training course, SRM system was useful and effective in terms of positional reproducibility and patient compliance.

  18. Adapt

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  19. Tumour-specific metabolic adaptation to acidosis is coupled to epigenetic stability in osteosarcoma cells.

    Chano, Tokuhiro; Avnet, Sofia; Kusuzaki, Katsuyuki; Bonuccelli, Gloria; Sonveaux, Pierre; Rotili, Dante; Mai, Antonello; Baldini, Nicola

    2016-01-01

    The glycolytic-based metabolism of cancers promotes an acidic microenvironment that is responsible for increased aggressiveness. However, the effects of acidosis on tumour metabolism have been almost unexplored. By using capillary electrophoresis with time-of-flight mass spectrometry, we observed a significant metabolic difference associated with glycolysis repression (dihydroxyacetone phosphate), increase of amino acid catabolism (phosphocreatine and glutamate) and urea cycle enhancement (arginino succinic acid) in osteosarcoma (OS) cells compared with normal fibroblasts. Noteworthy, metabolites associated with chromatin modification, like UDP-glucose and N(8)-acetylspermidine, decreased more in OS cells than in fibroblasts. COBRA assay and acetyl-H3 immunoblotting indicated an epigenetic stability in OS cells than in normal cells, and OS cells were more sensitive to an HDAC inhibitor under acidosis than under neutral pH. Since our data suggest that acidosis promotes a metabolic reprogramming that can contribute to the epigenetic maintenance under acidosis only in tumour cells, the acidic microenvironment should be considered for future therapies. PMID:27186436

  20. Tumour-specific metabolic adaptation to acidosis is coupled to epigenetic stability in osteosarcoma cells

    Chano, Tokuhiro; Avnet, Sofia; Kusuzaki, Katsuyuki; Bonuccelli, Gloria; Sonveaux, Pierre; Rotili, Dante; Mai, Antonello; Baldini, Nicola

    2016-01-01

    The glycolytic-based metabolism of cancers promotes an acidic microenvironment that is responsible for increased aggressiveness. However, the effects of acidosis on tumour metabolism have been almost unexplored. By using capillary electrophoresis with time-of-flight mass spectrometry, we observed a significant metabolic difference associated with glycolysis repression (dihydroxyacetone phosphate), increase of amino acid catabolism (phosphocreatine and glutamate) and urea cycle enhancement (arginino succinic acid) in osteosarcoma (OS) cells compared with normal fibroblasts. Noteworthy, metabolites associated with chromatin modification, like UDP-glucose and N8-acetylspermidine, decreased more in OS cells than in fibroblasts. COBRA assay and acetyl-H3 immunoblotting indicated an epigenetic stability in OS cells than in normal cells, and OS cells were more sensitive to an HDAC inhibitor under acidosis than under neutral pH. Since our data suggest that acidosis promotes a metabolic reprogramming that can contribute to the epigenetic maintenance under acidosis only in tumour cells, the acidic microenvironment should be considered for future therapies. PMID:27186436

  1. Genome-scale reconstruction of Salinispora tropica CNB-440 metabolism to study strain-specific adaptation.

    Contador, C A; Rodríguez, V; Andrews, B A; Asenjo, J A

    2015-11-01

    The first manually curated genome-scale metabolic model for Salinispora tropica strain CNB-440 was constructed. The reconstruction enables characterization of the metabolic capabilities for understanding and modeling the cellular physiology of this actinobacterium. The iCC908 model was based on physiological and biochemical information of primary and specialised metabolism pathways. The reconstructed stoichiometric matrix consists of 1169 biochemical conversions, 204 transport reactions and 1317 metabolites. A total of 908 structural open reading frames (ORFs) were included in the reconstructed network. The number of gene functions included in the reconstructed network corresponds to 20% of all characterized ORFs in the S. tropica genome. The genome-scale metabolic model was used to study strain-specific capabilities in defined minimal media. iCC908 was used to analyze growth capabilities in 41 different minimal growth-supporting environments. These nutrient sources were evaluated experimentally to assess the accuracy of in silico growth simulations. The model predicted no auxotrophies for essential amino acids, which was corroborated experimentally. The strain is able to use 21 different carbon sources, 8 nitrogen sources and 4 sulfur sources from the nutrient sources tested. Experimental observation suggests that the cells may be able to store sulfur. False predictions provided opportunities to gain new insights into the physiology of this species, and to gap fill the missing knowledge. The incorporation of modifications led to increased accuracy in predicting the outcome of growth/no growth experiments from 76 to 93%. iCC908 can thus be used to define the metabolic capabilities of S. tropica and guide and enhance the production of specialised metabolites. PMID:26459337

  2. Improving traffic flow at a 2-to-1 lane reduction with wirelessly connected, adaptive cruise control vehicles

    Davis, L C

    2015-01-01

    Wirelessly connected vehicles that exchange information about traffic conditions can reduce delays caused by congestion. At a 2-to-1 lane reduction, the improvement in flow past a bottleneck due to traffic with a random mixture of 40% connected vehicles is found to be 52%. Control is based on connected-vehicle-reported velocities near the bottleneck. In response to indications of congestion the connected vehicles, which are also adaptive cruise control vehicles, reduce their speed in slowdown regions. Early lane changes of manually driven vehicles from the terminated lane to the continuous lane are induced by the slowing connected vehicles. Self-organized congestion at the bottleneck is thus delayed or eliminated, depending upon the incoming flow magnitude. For the large majority of vehicles, travel times past the bottleneck are substantially reduced. Control is responsible for delaying the onset of congestion as the incoming flow increases. Adaptive cruise control increases the flow out of the congested stat...

  3. Rician noise reduction in magnetic resonance images using adaptive non-local mean and guided image filtering

    Mahmood, Muhammad Tariq; Chu, Yeon-Ho; Choi, Young-Kyu

    2016-06-01

    This paper proposes a Rician noise reduction method for magnetic resonance (MR) images. The proposed method is based on adaptive non-local mean and guided image filtering techniques. In the first phase, a guidance image is obtained from the noisy image through an adaptive non-local mean filter. Sobel operators are applied to compute the strength of edges which is further used to control the spread of the kernel in non-local mean filtering. In the second phase, the noisy and the guidance images are provided to the guided image filter as input to restore the noise-free image. The improved performance of the proposed method is investigated using the simulated and real data sets of MR images. Its performance is also compared with the previously proposed state-of-the art methods. Comparative analysis demonstrates the superiority of the proposed scheme over the existing approaches.

  4. Artifact reduction of compressed images and video combining adaptive fuzzy filtering and directional anisotropic diffusion

    Nadernejad, Ehsan; Forchhammer, Søren; Korhonen, Jari

    2011-01-01

    and ringing artifacts, we have applied directional anisotropic diffusion. Besides that, the selection of the adaptive threshold parameter for the diffusion coefficient has also improved the performance of the algorithm. Experimental results on JPEG compressed images as well as MJPEG and H.264...

  5. Responses of mouse skeletal muscle to endurance exercise. Functional, metabolic, and genomic adaptations

    de Snoo, M.W.

    2009-01-01

    Endurance exercise is commonly known to improve skeletal muscle performance with respect to fatigue resistance. The exact mechanisms, however, as to how skeletal muscle adapts to increased physical demand are still largely unknown, despite extensive research. These processes were originally studied

  6. PGC-1alpha in exercise- and exercise training-induced metabolic adaptations

    Jørgensen, Stine Ringholm

    training, respectively, in WT mice while there was no change in PGC-1α KO mice. Furthermore, fasting increased G6Pase and PEPCK mRNA content in both WT and PGC-1α KO mice. This implies that exercise- and exercise training-induced improvements in hepatic oxidative capacity, but not regulation......The aim of the present thesis was to investigate the hypotheses that 1) bed rest reduces metabolic and angiogenic proteins and changes microRNA (miRNA) content as well as alters exercise-induced mRNA responses in human skeletal muscle, 2) Peroxisome proliferator-activated receptor-γ coactivator...... (PGC)-1α is required for exercise-, exercise training- and fasting-induced mRNA and protein responses, respectively, of metabolic, angiogenic and gluconeogenic proteins in liver and adipose tissue in mice, 3) PGC-1α is required for both exercise training and resveratrol mediated prevention of age...

  7. The impact of head movements on EEG and contact impedance: an adaptive filtering solution for motion artifact reduction.

    Mihajlovic, Vojkan; Patki, Shrishail; Grundlehner, Bernard

    2014-01-01

    Designing and developing a comfortable and convenient EEG system for daily usage that can provide reliable and robust EEG signal, encompasses a number of challenges. Among them, the most ambitious is the reduction of artifacts due to body movements. This paper studies the effect of head movement artifacts on the EEG signal and on the dry electrode-tissue impedance (ETI), monitored continuously using the imec's wireless EEG headset. We have shown that motion artifacts have huge impact on the EEG spectral content in the frequency range lower than 20 Hz. Coherence and spectral analysis revealed that ETI is not capable of describing disturbances at very low frequencies (below 2 Hz). Therefore, we devised a motion artifact reduction (MAR) method that uses a combination of a band-pass filtering and multi-channel adaptive filtering (AF), suitable for real-time MAR. This method was capable of substantially reducing artifacts produced by head movements. PMID:25571131

  8. A Novel Mathematical Model Describing Adaptive Cellular Drug Metabolism and Toxicity in the Chemoimmune System

    Tóth, Attila; Brózik, Anna; Szakács, Gergely; Sarkadi, Balázs; Hegedüs, Tamás

    2015-01-01

    Cells cope with the threat of xenobiotic stress by activating a complex molecular network that recognizes and eliminates chemically diverse toxic compounds. This “chemoimmune system” consists of cellular Phase I and Phase II metabolic enzymes, Phase 0 and Phase III ATP Binding Cassette (ABC) membrane transporters, and nuclear receptors regulating these components. In order to provide a systems biology characterization of the chemoimmune network, we designed a reaction kinetic model based on d...

  9. Gender-related effects on substrate utilization and metabolic adaptation in hairless spontaneously hypertensive rat

    Trnovská, J.; Šilhavý, Jan; Zídek, Václav; Šimáková, Miroslava; Mlejnek, Petr; Landa, Vladimír; Eigner, Sebastian; Eigner-Henke, Kateřina; Škop, V.; Oliyarnyk, O.; Kazdová, L.; Mráček, Tomáš; Houštěk, Josef; Pravenec, Michal

    2015-01-01

    Roč. 64, č. 1 (2015), s. 51-60. ISSN 0862-8408 R&D Projects: GA ČR(CZ) GB14-36804G; GA ČR(CZ) GA13-04420S; GA MŠk(CZ) LL1204; GA MZd(CZ) NT14325 Institutional support: RVO:67985823 ; RVO:61389005 Keywords : gender * hairless rat * metabolism * brown adipose tissue Subject RIV: ED - Physiology Impact factor: 1.293, year: 2014

  10. Adaptive evolution of energy metabolism genes and the origin of flight in bats

    Shen, Yong-Yi; Liang, Lu; Zhu, Zhou-Hai; Zhou, Wei-Ping; David M. Irwin; Zhang, Ya-Ping

    2010-01-01

    Bat flight poses intriguing questions about how flight independently developed in mammals. Flight is among the most energy-consuming activities. Thus, we deduced that changes in energy metabolism must be a primary factor in the origin of flight in bats. The respiratory chain of the mitochondrial produces 95% of the adenosine triphosphate (ATP) needed for locomotion. Because the respiratory chain has a dual genetic foundation, with genes encoded by both the mitochondrial and nuclear genomes, w...

  11. Exercise-Induced Skeletal Muscle Remodeling and Metabolic Adaptation: Redox Signaling and Role of Autophagy

    Ferraro, Elisabetta; Giammarioli, Anna Maria; Chiandotto, Sergio; Spoletini, Ilaria; Rosano, Giuseppe

    2014-01-01

    Significance: Skeletal muscle is a highly plastic tissue. Exercise evokes signaling pathways that strongly modify myofiber metabolism and physiological and contractile properties of skeletal muscle. Regular physical activity is beneficial for health and is highly recommended for the prevention of several chronic conditions. In this review, we have focused our attention on the pathways that are known to mediate physical training-induced plasticity. Recent Advances: An important role for redox ...

  12. Harm reduction as a complex adaptive system: A dynamic framework for analyzing Tanzanian policies concerning heroin use.

    Ratliff, Eric A; Kaduri, Pamela; Masao, Frank; Mbwambo, Jessie K K; McCurdy, Sheryl A

    2016-04-01

    Contrary to popular belief, policies on drug use are not always based on scientific evidence or composed in a rational manner. Rather, decisions concerning drug policies reflect the negotiation of actors' ambitions, values, and facts as they organize in different ways around the perceived problems associated with illicit drug use. Drug policy is thus best represented as a complex adaptive system (CAS) that is dynamic, self-organizing, and coevolving. In this analysis, we use a CAS framework to examine how harm reduction emerged around heroin trafficking and use in Tanzania over the past thirty years (1985-present). This account is an organizational ethnography based on of the observant participation of the authors as actors within this system. We review the dynamic history and self-organizing nature of harm reduction, noting how interactions among system actors and components have coevolved with patterns of heroin us, policing, and treatment activities over time. Using a CAS framework, we describe harm reduction as a complex process where ambitions, values, facts, and technologies interact in the Tanzanian sociopolitical environment. We review the dynamic history and self-organizing nature of heroin policies, noting how the interactions within and between competing prohibitionist and harm reduction policies have changed with patterns of heroin use, policing, and treatment activities over time. Actors learn from their experiences to organize with other actors, align their values and facts, and implement new policies. Using a CAS approach provides researchers and policy actors a better understanding of patterns and intricacies in drug policy. This knowledge of how the system works can help improve the policy process through adaptive action to introduce new actors, different ideas, and avenues for communication into the system. PMID:26790689

  13. THEORETICAL INVESTIGATION INTO THE POTENTIAL OF HALOGENATED METHANES TO UNDERGO REDUCTIVE METABOLISM

    The density-functional theory (DFT) based computational chemistry software package DMol was used to provide insight into the reductive potentials of a series of halomethanes. t is known that certain members of this series are readily reduced in vivo via catalysis by cytochrome P4...

  14. Adaptive reduction of the vibrations from a vacuum pump for high-precision equipment

    Berkhoff, A.P.; Wesselink, J.M.; Basten, T.G.H.

    2008-01-01

    This paper describes experiments with active vibration reduction on a setup with a vacuum pump that is tightly coupled with high-precision equipment. The precision of this equipment is critically dependent on the level of the vibrations that are introduced by the vacuum pump. The vibrations were red

  15. Ready for the Storm: Education for Disaster Risk Reduction and Climate Change Adaptation and Mitigation

    Kagawa, Fumiyo; Selby, David

    2012-01-01

    Incidences of disaster and climate change impacts are rising globally. Disaster risk reduction and climate change education are two educational responses to present and anticipated increases in the severity and frequency of hazards. They share significant complementarities and potential synergies, the latter as yet largely unexploited. Three…

  16. Adaptive thermogenesis and uncoupling proteins: a reappraisal of their roles in fat metabolism and energy balance

    Dulloo, Abdul G; Seydoux, Josiane; JACQUET, JEAN

    2005-01-01

    After decades of controversies about the quantitative importance of autoregulatory adjustments in energy expenditure in weight regulation, there is now increasing recognition that even subtle variations in thermogenesis could, in dynamic systems and over the long term, be important in determining weight maintenance in some and obesity in others. The main challenge nowadays is to provide a mechanistic explanation for the role of adaptive thermogenesis in attenuating and correcting deviations o...

  17. Effective long term adaptation and metabolic state regulation of ski-racers

    Bakhareva A.S.; Isaev A.P.; Erlikh V.V.; Aminov A.S.

    2016-01-01

    Purpose: to scientifically substantiate effective mechanisms of organism’s bio-chemical adaptation of ski-racers in competition period with the help of lipid peroxidation indicators, oxidative modification of proteins and activity of hypothalamus pituitary adrenocortical system. Material: in the research 14 sportsmen of 18-25 years’ age (combined team of university) with different level of sportsmanship participated. Assessment of free radical oxidation, anti-oxidant system, cortisol level wa...

  18. Differential Roles of the TRAF3 Adapter Protein in Adipogenesis and Glucose Metabolism

    Loo, Lotus Kyi

    2015-01-01

    The main goal of this project is to delineate the roles and mechanisms of constitutive type II nuclear factor-kappa B (NF-kB) activation on adipogenesis and glucose metabolism. Our laboratory has shown that the tumor necrosis factor (TNF) receptor-associated factor 3 (TRAF3) is a critical negative modulator of type II NF-kB and TRAF3 knockout (TRAF3-/-) have constitutive activation of non canonical or type II NF-kB pathway. However, TRAF3-/- pups die within two weeks after birth and the funct...

  19. Data reduction in the ITMS system through a data acquisition model with self-adaptive sampling rate

    Ruiz, M. [Grupo de Investigacion en Instrumentacion y Acustica Aplicada, Universidad Politecnica de Madrid (UPM), Crta. Valencia Km-7, Madrid 28031 (Spain)], E-mail: mariano.ruiz@upm.es; Lopez, JM.; Arcas, G. de [Grupo de Investigacion en Instrumentacion y Acustica Aplicada, Universidad Politecnica de Madrid (UPM), Crta. Valencia Km-7, Madrid 28031 (Spain); Barrera, E. [Departamento de Sistemas Electronicos y de Control, Universidad Politecnica de Madrid (UPM), Crta. Valencia Km-7, Madrid 28031 (Spain); Melendez, R. [Grupo de Investigacion en Instrumentacion y Acustica Aplicada, Universidad Politecnica de Madrid (UPM), Crta. Valencia Km-7, Madrid 28031 (Spain); Vega, J. [Asociacion EURATOM/CIEMAT para Fusion, Madrid (Spain)

    2008-04-15

    Long pulse or steady state operation of fusion experiments require data acquisition and processing systems that reduce the volume of data involved. The availability of self-adaptive sampling rate systems and the use of real-time lossless data compression techniques can help solve these problems. The former is important for continuous adaptation of sampling frequency for experimental requirements. The latter allows the maintenance of continuous digitization under limited memory conditions. This can be achieved by permanent transmission of compressed data to other systems. The compacted transfer ensures the use of minimum bandwidth. This paper presents an implementation based on intelligent test and measurement system (ITMS), a data acquisition system architecture with multiprocessing capabilities that permits it to adapt the system's sampling frequency throughout the experiment. The sampling rate can be controlled depending on the experiment's specific requirements by using an external dc voltage signal or by defining user events through software. The system takes advantage of the high processing capabilities of the ITMS platform to implement a data reduction mechanism based in lossless data compression algorithms which are themselves based in periodic deltas.

  20. Reduction of cardiac and pulmonary complication probabilities after breathing adapted radiotherapy for breast cancer

    Korreman, Stine S; Pedersen, Anders N; Juhler-Nøttrup, Trine;

    2006-01-01

    PURPOSE: Substantial reductions of cardio-pulmonary radiation doses can be achieved using voluntary deep inspiration breath-hold (DIBH) or free breathing inspiration gating (IG) in radiotherapy after conserving surgery for breast cancer. The purpose of this study is to evaluate the radiobiologica...... voluntary DIBH and free breathing IG to reduce the risk of both cardiac mortality and pneumonitis for the common technique of adjuvant tangential breast irradiation.......PURPOSE: Substantial reductions of cardio-pulmonary radiation doses can be achieved using voluntary deep inspiration breath-hold (DIBH) or free breathing inspiration gating (IG) in radiotherapy after conserving surgery for breast cancer. The purpose of this study is to evaluate the radiobiological...... implications of such dosimetric benefits. METHODS AND MATERIALS: Patients from previously reported studies were pooled for a total of 33 patients. All patients underwent DIBH and free breathing (FB) scans, and 17 patients underwent an additional IG scan. Tangential conformal treatment plans covering the...

  1. The Microbial Metabolic Characteristics in the Course of Sulfate-Reduction

    2004-01-01

    Acid-producing phase reactor of two-phase anaerobic treatment process has remarkable advantages treating sulfate-laden wastewater. In order to investigate SRB population's capability of utilizing substrate and the microbial acidification type formed during the course of sulfate reduction, continuous-flow and batch tests were conducted in a continuous stirred tank bio-film reactor supplied with sodium sulfate as electron acceptor. The experimental results demonstrated that the acidification type formed b...

  2. A novel mathematical model describing adaptive cellular drug metabolism and toxicity in the chemoimmune system.

    Attila Tóth

    Full Text Available Cells cope with the threat of xenobiotic stress by activating a complex molecular network that recognizes and eliminates chemically diverse toxic compounds. This "chemoimmune system" consists of cellular Phase I and Phase II metabolic enzymes, Phase 0 and Phase III ATP Binding Cassette (ABC membrane transporters, and nuclear receptors regulating these components. In order to provide a systems biology characterization of the chemoimmune network, we designed a reaction kinetic model based on differential equations describing Phase 0-III participants and regulatory elements, and characterized cellular fitness to evaluate toxicity. In spite of the simplifications, the model recapitulates changes associated with acquired drug resistance and allows toxicity predictions under variable protein expression and xenobiotic exposure conditions. Our simulations suggest that multidrug ABC transporters at Phase 0 significantly facilitate the defense function of successive network members by lowering intracellular drug concentrations. The model was extended with a novel toxicity framework which opened the possibility of performing in silico cytotoxicity assays. The alterations of the in silico cytotoxicity curves show good agreement with in vitro cell killing experiments. The behavior of the simplified kinetic model suggests that it can serve as a basis for more complex models to efficiently predict xenobiotic and drug metabolism for human medical applications.

  3. The adaptive metabolic response involves specific protein glutathionylation during the filamentation process in the pathogen Candida albicans.

    Gergondey, R; Garcia, C; Serre, V; Camadro, J M; Auchère, F

    2016-07-01

    Candida albicans is an opportunist pathogen responsible for a large spectrum of infections, from superficial mycosis to the systemic disease candidiasis. Its ability to adopt various morphological forms, such as unicellular yeasts, filamentous pseudohyphae and hyphae, contributes to its ability to survive within the host. It has been suggested that the antioxidant glutathione is involved in the filamentation process. We investigated S-glutathionylation, the reversible binding of glutathione to proteins, and the functional consequences on C. albicans metabolic remodeling during the yeast-to-hyphae transition. Our work provided evidence for the specific glutathionylation of mitochondrial proteins involved in bioenergetics pathways in filamentous forms and a regulation of the main enzyme of the glyoxylate cycle, isocitrate lyase, by glutathionylation. Isocitrate lyase inactivation in the hyphal forms was reversed by glutaredoxin treatment, in agreement with a glutathionylation process, which was confirmed by proteomic data showing the binding of one glutathione molecule to the enzyme (data are available via ProteomeXchange with identifier PXD003685). We also assessed the effect of alternative carbon sources on glutathione levels and isocitrate lyase activity. Changes in nutrient availability led to morphological flexibility and were related to perturbations in glutathione levels and isocitrate lyase activity, confirming the key role of the maintenance of intracellular redox status in the adaptive metabolic strategy of the pathogen. PMID:27083931

  4. Design, Fabrication, and Testing of SMA Enabled Adaptive Chevrons for Jet Noise Reduction

    Turner, Travis L.; Buehrle, Ralph D.; Cano, Roberto J.; Fleming, Gary A.

    2004-01-01

    This study presents the status and results from an effort to design, fabricate, and test an adaptive jet engine chevron concept based upon embedding shape memory alloy (SMA) actuators in a composite laminate, termed a SMA hybrid composite (SMAHC). The approach for fabricating the adaptive SMAHC chevrons involves embedding prestrained Nitinol actuators on one side of the mid-plane of the composite laminate such that thermal excitation generates a thermal moment and deflects the structure. A glass-epoxy pre-preg/Nitinol ribbon material system and a vacuum hot press consolidation approach are employed. A versatile test system for control and measurement of the chevron deflection performance is described. Projection moire interferometry (PMI) is used for global deformation measurement and infrared (IR) thermography is used for 2-D temperature measurement and feedback control. A recently commercialized constitutive model for SMA and SMAHC materials is used in the finite element code ABAQUS to perform nonlinear static analysis of the chevron prototypes. Excellent agreement is achieved between the predicted and measured chevron deflection performance, thereby validating the design tool. Although the performance results presented in this paper fall short of the requirement, the concept is proven and an approach for achieving the performance objectives is evident.

  5. Reduction of EEG artifacts in simultaneous EEG-fMRI: Reference layer adaptive filtering (RLAF).

    Steyrl, David; Patz, Franz; Krausz, Gunther; Edlinger, Günter; Müller-Putz, Gernot R

    2015-08-01

    Although simultaneous measurement of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) is one of the most valuable methods for studying human brain activity non-invasively, it remains challenging to measure high quality EEG inside the MRI scanner. Recently, a new approach for minimizing residual MRI scanner artifacts in the EEG was presented: reference layer artifact subtraction (RLAS). Here, reference electrodes capture only the artifacts, which are subsequently subtracted from the measurement electrodes. With the present work we demonstrate that replacing the subtraction by adaptive filtering statistically significantly outperforms RLAS. Reference layer adaptive filtering (RLAF) attenuates the average artifact root-mean-square (RMS) voltage of the passive MRI scanner to 0.7 μV (-14.4 dB). RLAS achieves 0.78 μV (-13.5 dB). The combination of average artifact subtraction (AAS) and RLAF reduces the residual average gradient artifact RMS voltage to 2.3 μV (-49.2 dB). AAS alone achieves 5.7 μV (-39.0 dB). All measurements were conducted with an MRI phantom, as the reference layer cap available to us was a prototype. PMID:26737122

  6. Reductions in knee joint forces with weight loss are attenuated by gait adaptations in class III obesity.

    DeVita, Paul; Rider, Patrick; Hortobágyi, Tibor

    2016-03-01

    A consensus exists that high knee joint forces are a precursor to knee osteoarthritis and weight loss reduces these forces. Because large weight loss also leads to increased step length and walking velocity, knee contact forces may be reduced less than predicted by the magnitude of weight loss. The purpose was to determine the effects of weight loss on knee muscle and joint loads during walking in Class III obese adults. We determined through motion capture, force platform measures and biomechanical modeling the effects of weight loss produced by gastric bypass surgery over one year on knee muscle and joint loads during walking at a standard, controlled velocity and at self-selected walking velocities. Weight loss equaling 412N or 34% of initial body weight reduced maximum knee compressive force by 824N or 67% of initial body weight when walking at the controlled velocity. These changes represent a 2:1 reduction in knee force relative to weight loss when walking velocity is constrained to the baseline value. However, behavioral adaptations including increased stride length and walking velocity in the self-selected velocity condition attenuated this effect by ∼50% leading to a 392N or 32% initial body weight reduction in compressive force in the knee joint. Thus, unconstrained walking elicited approximately 1:1 ratio of reduction in knee force relative to weight loss and is more indicative of walking behavior than the standard velocity condition. In conclusion, massive weight loss produces dramatic reductions in knee forces during walking but when patients stride out and walk faster, these favorable reductions become substantially attenuated. PMID:26979878

  7. Partial restoration of dietary fat induced metabolic adaptations to training by 7 days of carbohydrate diet

    Helge, Jørn Wulff; Watt, Peter W; Richter, Erik A;

    2002-01-01

    -fat (Fat-CHO; 62% fat, 21% carbohydrate) and 6 a high-carbohydrate diet (CHO; 20% fat, 65% carbohydrate) for 7 wk, and thereafter both groups consumed the carbohydrate diet for an eighth week. Training was performed throughout. After 8 wk, during 60 min of exercise (71 +/- 1% pretraining maximal oxygen...... +/- 59 vs. 688 +/- 43 mmol/kg dry wt) in Fat-CHO than in CHO. In conclusion, shift to carbohydrate diet after prolonged adaptation to fat diet and training causes increased resting muscle glycogen levels but impaired leg glucose uptake and similar muscle glycogen breakdown, despite higher resting levels......, compared with when the carbohydrate diet is consumed throughout training....

  8. Improving traffic flow at a 2-to-1 lane reduction with wirelessly connected, adaptive cruise control vehicles

    Davis, L. C.

    2016-06-01

    Wirelessly connected vehicles that exchange information about traffic conditions can reduce delays caused by congestion. At a 2-to-1 lane reduction, the improvement in flow past a bottleneck due to traffic with a random mixture of 40% connected vehicles is found to be 52%. Control is based on connected-vehicle-reported velocities near the bottleneck. In response to indications of congestion the connected vehicles, which are also adaptive cruise control vehicles, reduce their speed in slowdown regions. Early lane changes of manually driven vehicles from the terminated lane to the continuous lane are induced by the slowing connected vehicles. Self-organized congestion at the bottleneck is thus delayed or eliminated, depending upon the incoming flow magnitude. For the large majority of vehicles, travel times past the bottleneck are substantially reduced. Control is responsible for delaying the onset of congestion as the incoming flow increases. Adaptive cruise control increases the flow out of the congested state at the bottleneck. The nature of the congested state, when it occurs, appears to be similar under a variety of conditions. Typically 80-100 vehicles are approximately equally distributed between the lanes in the 500 m region prior to the end of the terminated lane. Without the adaptive cruise control capability, connected vehicles can delay the onset of congestion but do not increase the asymptotic flow past the bottleneck. Calculations are done using the Kerner-Klenov three-phase theory, stochastic discrete-time model for manual vehicles. The dynamics of the connected vehicles is given by a conventional adaptive cruise control algorithm plus commanded deceleration. Because time in the model for manual vehicles is discrete (one-second intervals), it is assumed that the acceleration of any vehicle immediately in front of a connected vehicle is constant during the time interval, thereby preserving the computational simplicity and speed of a discrete-time model.

  9. Involvement of anti-oxidative enzymes, photosynthetic pigments and flavonoid metabolism in the adaptation of Reaumuria soongorica to salt stress

    YuBing Liu; Bo Cao; MeiLing Liu

    2013-01-01

    Reaumuria soongorica is a short woody shrub widely found in semi-arid areas of China. It can survive severe environ-mental stress including high salinity in its natural habitat. Thus, we investigated the involvement of anti-oxidative enzymes, photosynthetic pigments and flavonoid metabolism in the adaptation of R. soongorica to saline environments. R. soon-gorica was treated with 0, 100, 200 and 400 mM NaCl solutions for 14 days. Soil salt content increased significantly by watering with high content of NaCl solution, and no variation between 8 and 14 days during treatment. The levels of pe-roxidation of lipid membranes (measured by malondialdehyde content) and the activities of three antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD) and ascorbate peroxidase (APX)) increased under salt stress. Chlorophyll and carotenoid content decreased with increasing salt content. The ratio of Chl a/Chl b and carotenoid/Chl exhibited sig-nificant increase under 400 mM NaCl. However, total flavonoid and anthocyanin contents and key enzyme activities in the flavonoid pathway including phenylalanine ammonialyase (PAL) and Chalcone isomerase (CHI) decreased under salt stress. These findings possibly suggest that R. soongorica has an adaptation protection mechanism against salt-induced oxidative damage by inducing the activity of antioxidant enzymes and maintaining a steady level of carotenoid/Chl.

  10. Molecular analyis of rates of metal reductions and metabolic state of Geobacter species

    This project began with the simple goal of trying to understand the diversity of dissimilatory metal-reducing microorganisms that might be found in subsurface environments. It ended with a sophisticated understanding not only of what microorganisms are important for metal reduction in uranium-contaminated subsurface environments, but also their physiological status during in situ uranium bioremediation. These findings have provided unprecedented insight into uranium bioremediation and the methods by which this process might be optimized. A brief summary of the major accomplishments of the project is given.

  11. Possible association of high urinary magnesium and taurine to creatinine ratios with metabolic syndrome risk reduction in Australian aboriginals.

    Hamada, Atsumi; Taguchi, Takashi; Mori, Hideki; Thorpe, Marjorie; Yamori, Yukio; Mori, Mari

    2011-01-01

    Background. Because of the epidemic of metabolic syndrome (MS) in Australian Aboriginals known for their higher cardiovascular mortality and shorter life expectancy, we analyzed the possible relationship of their MS risks with the current dietary custom. Methods. The subjects were 84 people aged 16-79 years. The health examination was conducted according to the basic protocol of WHO-CARDIAC (Cardiovascular Diseases and Alimentary Comparison) Study. Results. The highest prevalence among MS risks was abdominal obesity (over 60%). After controlling for age and sex, the odds of obesity decreased significantly with high level of urinary magnesium/creatinine ratio (Mg/cre) (OR, 0.11; 95% CI, 0.02-0.57; P Aboriginal people of this area may partly be due to the reduction of beneficial nutrients intake including Mg and taurine. PMID:21738855

  12. Nuclear hormone receptors as mediators of metabolic adaptability following reproductive perturbations.

    Ratnappan, Ramesh; Ward, Jordan D; Yamamoto, Keith R; Ghazi, Arjumand

    2016-01-01

    Previously, we identified a group of nuclear hormone receptors (NHRs) that promote longevity in the nematode Caenorhabditis elegans following germline-stem cell (GSC) loss. This group included NHR-49, the worm protein that performs functions similar to vertebrate PPARα, a key regulator of lipid metabolism. We showed that NHR-49/PPARα enhances mitochondrial β-oxidation and fatty acid desaturation upon germline removal, and through the coordinated enhancement of these processes allows the animal to retain lipid homeostasis and undergo lifespan extension. NHR-49/PPARα expression is elevated in GSC-ablated animals, in part, by DAF-16/FOXO3A and TCER-1/TCERG1, two other conserved, pro-longevity transcriptional regulators that are essential for germline-less longevity. In exploring the roles of the other pro-longevity NHRs, we discovered that one of them, NHR-71/HNF4, physically interacted with NHR-49/PPARα. NHR-71/HNF4 did not have a broad impact on the expression of β-oxidation and desaturation targets of NHR-49/PPARα. But, both NHR-49/PPARα and NHR-71/HNF4 were essential for the increased expression of DAF-16/FOXO3A- and TCER-1/TCERG1-downstream target genes. In addition, nhr-49 inactivation caused a striking membrane localization of KRI-1, the only known common upstream regulator of DAF-16/FOXO3A and TCER-1/TCERG1, suggesting that it may operate in a positive feedback loop to potentiate the activity of this pathway. These data underscore how selective interactions between NHRs that function as nodes in metabolic networks, confer functional specificity in response to different physiological stimuli. PMID:27073739

  13. Implementation of Adaptive Filter Structures on a Fixed Point Signal Processor for Acoustical Noise Reduction

    Chunduri, Krishna Chaitanya; Gutti, Chalapathi

    2005-01-01

    The problem of controlling the noise level in the environment has been the focus of a tremendous amount of research over the years. Active Noise Cancellation (ANC) is one such approach that has been proposed for reduction of steady state noise. ANC refers to an electromechanical or electro acoustic technique of canceling an acoustic disturbance to yield a quieter environment. The basic principle of ANC is to introduce a canceling “anti-noise” signal that has the same amplitude but the exact o...

  14. Adaptive filtering for reduction of speckle in ultrasonic pulse-echo images.

    Bamber, J C; Daft, C

    1986-01-01

    Current medical ultrasonic scanning instrumentation permits the display of fine image detail (speckle) which does not transfer useful information but degrades the apparent low contrast resolution in the image. An adaptive two-dimensional filter has been developed which uses local features of image texture to recognize and maximally low-pass filter those parts of the image which correspond to fully developed speckle, while substantially preserving information associated with resolved-object structure. A first implementation of the filter is described which uses the ratio of the local variance and the local mean as the speckle recognition feature. Preliminary results of applying this form of display processing to medical ultrasound images are very encouraging; it appears that the visual perception of features such as small discrete structures, subtle fluctuations in mean echo level and changes in image texture may be enhanced relative to that for unprocessed images. PMID:3510500

  15. Poverty reduction, climate change mitigation and adaptation : the need for intermediate public policies harnessing technology appropriation

    Rynikiewicz, Christophe; Chetaille, Anne

    2006-01-01

    L'intérêt pour des approches réalistes qui combineraient adaptation, lutte contre les dérèglements climatiques et réduction des inégalités et de la pauvreté est grandissant. Toutefois, les défis sont nombreux. La vulnérabilité des pays des Sud est reconnue. Tandis que l'accès à l'énergie et la demande d'énergie et matériaux pour l'industrialisation est une priorité de nombreux gouvernements, la prise en compte de la contrainte climatique conduirait à des modes de développement moins intensifs...

  16. Hyperosmolar sodium chloride is toxic to cultured neurons and causes reduction of glucose metabolism and ATP levels, an increase in glutamate uptake, and a reduction in cytosolic calcium.

    Morland, Cecilie; Pettersen, Mi Nguyen; Hassel, Bjørnar

    2016-05-01

    Elevation of serum sodium, hypernatremia, which may occur during dehydration or treatment with sodium chloride, may cause brain dysfunction and damage, but toxic mechanisms are poorly understood. We found that exposure to excess NaCl, 10-100mmol/L, for 20h caused cell death in cultured cerebellar granule cells (neurons). Toxicity was due to Na(+), since substituting excess Na(+) with choline reduced cell death to control levels, whereas gluconate instead of excess Cl(-) did not. Prior to cell death from hyperosmolar NaCl, glucose consumption and lactate formation were reduced, and intracellular aspartate levels were elevated, consistent with reduced glycolysis or glucose uptake. Concomitantly, the level of ATP became reduced. Pyruvate, 10mmol/L, reduced NaCl-induced cell death. The extracellular levels of glutamate, taurine, and GABA were concentration-dependently reduced by excess NaCl; high-affinity glutamate uptake increased. High extracellular [Na(+)] caused reduction in intracellular free [Ca(2+)], but a similar effect was seen with mannitol, which was not neurotoxic. We suggest that inhibition of glucose metabolism with ensuing loss of ATP is a neurotoxic mechanism of hyperosmolar sodium, whereas increased uptake of extracellular neuroactive amino acids and reduced intracellular [Ca(2+)] may, if they occur in vivo, contribute to the cerebral dysfunction and delirium described in hypernatremia. PMID:26994581

  17. Adaptive mutations in sugar metabolism restore growth on glucose in a pyruvate decarboxylase negative yeast strain

    Zhang, Yiming; Liu, Guodong; Engqvist, Martin K. M.;

    2015-01-01

    carbon source, and requires supplementation of C2 compounds to the medium in order to meet the requirement for cytosolic acetyl-CoA for biosynthesis of fatty acids and ergosterol. Results: In this study, a Pdc negative strain was adaptively evolved for improved growth in glucose medium via serial......Background: A Saccharomyces cerevisiae strain carrying deletions in all three pyruvate decarboxylase (PDC) genes (also called Pdc negative yeast) represents a non-ethanol producing platform strain for the production of pyruvate derived biochemicals. However, it cannot grow on glucose as the sole...... transfer, resulting in three independently evolved strains, which were able to grow in minimal medium containing glucose as the sole carbon source at the maximum specific rates of 0.138, 0.148, 0.141 h-1, respectively. Several genetic changes were identified in the evolved Pdc negative strains by genomic...

  18. Reduction of nuclear encoded enzymes of mitochondrial energy metabolism in cells devoid of mitochondrial DNA

    Mueller, Edith E., E-mail: ed.mueller@salk.at [Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Muellner Hauptstrasse 48, 5020 Salzburg (Austria); Mayr, Johannes A., E-mail: h.mayr@salk.at [Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Muellner Hauptstrasse 48, 5020 Salzburg (Austria); Zimmermann, Franz A., E-mail: f.zimmermann@salk.at [Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Muellner Hauptstrasse 48, 5020 Salzburg (Austria); Feichtinger, Rene G., E-mail: r.feichtinger@salk.at [Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Muellner Hauptstrasse 48, 5020 Salzburg (Austria); Stanger, Olaf, E-mail: o.stanger@rbht.nhs.uk [Department of Cardiac Surgery, Paracelsus Medical University, Muellner Hauptstrasse 48, 5020 Salzburg (Austria); Sperl, Wolfgang, E-mail: w.sperl@salk.at [Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Muellner Hauptstrasse 48, 5020 Salzburg (Austria); Kofler, Barbara, E-mail: b.kofler@salk.at [Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Muellner Hauptstrasse 48, 5020 Salzburg (Austria)

    2012-01-20

    Highlights: Black-Right-Pointing-Pointer We examined OXPHOS and citrate synthase enzyme activities in HEK293 cells devoid of mtDNA. Black-Right-Pointing-Pointer Enzymes partially encoded by mtDNA show reduced activities. Black-Right-Pointing-Pointer Also the entirely nuclear encoded complex II and citrate synthase exhibit reduced activities. Black-Right-Pointing-Pointer Loss of mtDNA induces a feedback mechanism that downregulates complex II and citrate synthase. -- Abstract: Mitochondrial DNA (mtDNA) depletion syndromes are generally associated with reduced activities of oxidative phosphorylation (OXPHOS) enzymes that contain subunits encoded by mtDNA. Conversely, entirely nuclear encoded mitochondrial enzymes in these syndromes, such as the tricarboxylic acid cycle enzyme citrate synthase (CS) and OXPHOS complex II, usually exhibit normal or compensatory enhanced activities. Here we report that a human cell line devoid of mtDNA (HEK293 {rho}{sup 0} cells) has diminished activities of both complex II and CS. This finding indicates the existence of a feedback mechanism in {rho}{sup 0} cells that downregulates the expression of entirely nuclear encoded components of mitochondrial energy metabolism.

  19. Reduction of nuclear encoded enzymes of mitochondrial energy metabolism in cells devoid of mitochondrial DNA

    Highlights: ► We examined OXPHOS and citrate synthase enzyme activities in HEK293 cells devoid of mtDNA. ► Enzymes partially encoded by mtDNA show reduced activities. ► Also the entirely nuclear encoded complex II and citrate synthase exhibit reduced activities. ► Loss of mtDNA induces a feedback mechanism that downregulates complex II and citrate synthase. -- Abstract: Mitochondrial DNA (mtDNA) depletion syndromes are generally associated with reduced activities of oxidative phosphorylation (OXPHOS) enzymes that contain subunits encoded by mtDNA. Conversely, entirely nuclear encoded mitochondrial enzymes in these syndromes, such as the tricarboxylic acid cycle enzyme citrate synthase (CS) and OXPHOS complex II, usually exhibit normal or compensatory enhanced activities. Here we report that a human cell line devoid of mtDNA (HEK293 ρ0 cells) has diminished activities of both complex II and CS. This finding indicates the existence of a feedback mechanism in ρ0 cells that downregulates the expression of entirely nuclear encoded components of mitochondrial energy metabolism.

  20. Linear adaptive noise-reduction filters for tomographic imaging: Optimizing for minimum mean square error

    Sun, W Y [Lawrence Berkeley Lab., CA (United States)

    1993-04-01

    This thesis solves the problem of finding the optimal linear noise-reduction filter for linear tomographic image reconstruction. The optimization is data dependent and results in minimizing the mean-square error of the reconstructed image. The error is defined as the difference between the result and the best possible reconstruction. Applications for the optimal filter include reconstructions of positron emission tomographic (PET), X-ray computed tomographic, single-photon emission tomographic, and nuclear magnetic resonance imaging. Using high resolution PET as an example, the optimal filter is derived and presented for the convolution backprojection, Moore-Penrose pseudoinverse, and the natural-pixel basis set reconstruction methods. Simulations and experimental results are presented for the convolution backprojection method.

  1. Synergy between 13C-metabolic flux analysis and flux balance analysis for understanding metabolic adaption to anaerobiosis in e. coli

    Genome-based Flux Balance Analysis (FBA, constraints based flux analysis) and steady state isotopic-labeling-based Metabolic Flux Analysis (MFA) are complimentary approaches to predicting and measuring the operation and regulation of metabolic networks. Here a genome-derived model of E. coli metabol...

  2. Rapid temperature adaptation in trout: Alterations in membrane molecular species metabolism

    Williams, E.E.; Hazel, J.R. (Arizona State Univ., Tempe (United States))

    1991-03-11

    The ability of poikilotherms to change their membrane phospholipid composition in response to long term temperature change is well documented. Less understood are the changes which occur when rapid temperature fluctuations are encountered. The authors have followed the fate of 16:0/18:1 phosphatidylcholine (PC), radiocarbon labeled at the 18:1 acyl chain, in the plasma membranes of trout hepatocytes. After isolation by PC, 5%-10% of which was taken up into the plasma membranes. The cells were then divided into two groups and either held at acclimation temperature or transferred to 5C. After 1 hour at 20C or 5 hours at 5C the plasma membranes were isolated, the lipids extracted, and the PC fraction was resolved into its molecular species. The distribution of radiolabel between the warm and cold exposed cells was then determined. In both groups radioactivity was found in molecular species other than 16:0/18:1, however no radioactivity was found in lipids other than PC. Cold exposed cells contained less radioactivity in 18:2/18:2, 20:1/22:6, 16:0/18:2 and 18:0/18:1 PC than the warm cells, but contained more in 18:1/18:1 PC. These results indicate that the environmental temperature influences the rates of in situ desaturation, chain elongation, and intermolecular acyl chain regroupings. Subtle changes in molecular species metabolism might be important early steps in temperature acclimation.

  3. Role of Hypothalamic VGF in Energy Balance and Metabolic Adaption to Environmental Enrichment in Mice.

    Foglesong, Grant D; Huang, Wei; Liu, Xianglan; Slater, Andrew M; Siu, Jason; Yildiz, Vedat; Salton, Stephen R J; Cao, Lei

    2016-03-01

    Environmental enrichment (EE), a housing condition providing complex physical, social, and cognitive stimulation, leads to improved metabolic health and resistance to diet-induced obesity and cancer. One underlying mechanism is the activation of the hypothalamic-sympathoneural-adipocyte axis with hypothalamic brain-derived neurotrophic factor (BDNF) as the key mediator. VGF, a peptide precursor particularly abundant in the hypothalamus, was up-regulated by EE. Overexpressing BDNF or acute injection of BDNF protein to the hypothalamus up-regulated VGF, whereas suppressing BDNF signaling down-regulated VGF expression. Moreover, hypothalamic VGF expression was regulated by leptin, melanocortin receptor agonist, and food deprivation mostly paralleled to BDNF expression. Recombinant adeno-associated virus-mediated gene transfer of Cre recombinase to floxed VGF mice specifically decreased VGF expression in the hypothalamus. In contrast to the lean and hypermetabolic phenotype of homozygous germline VGF knockout mice, specific knockdown of hypothalamic VGF in male adult mice led to increased adiposity, decreased core body temperature, reduced energy expenditure, and impaired glucose tolerance, as well as disturbance of molecular features of brown and white adipose tissues without effects on food intake. However, VGF knockdown failed to block the EE-induced BDNF up-regulation or decrease of adiposity indicating a minor role of VGF in the hypothalamic-sympathoneural-adipocyte axis. Taken together, our results suggest hypothalamic VGF responds to environmental demands and plays an important role in energy balance and glycemic control likely acting in the melanocortin pathway downstream of BDNF. PMID:26730934

  4. The role of active arsenic species produced by metabolic reduction of dimethylarsinic acid in genotoxicity and tumorigenesis

    In recent research of arsenic carcinogenesis, many researchers have directed their attention to methylated metabolites of inorganic arsenics. Because of its high cytotoxicity and genotoxicity, trivalent dimethylated arsenic, which can be produced by the metabolic reduction of dimethylarsinic acid (DMA), has attracted considerable attention from the standpoint of arsenic carcinogenesis. In the present paper, we examined trivalent dimethylated arsenic and its further metabolites for their chemical properties and biological behavior such as genotoxicity and tumorigenicity. Our in vitro and in vivo experiments suggested that the formation of cis-thymine glycol in DNA was induced via the production of dimethylated arsenic peroxide by the reaction of trivalent dimethylated arsenic with molecular oxygen, but not via the production of common reactive oxygen species (ROS; superoxide, hydrogen peroxide, hydroxyl radical, etc.). Thus, dimethylated arsenic peroxide may be the main species responsible for the tumor promotion in skin tumorigenesis induced by exposure to DMA. Free radical species, such as dimethylarsenic radical [(CH3)2As·] and dimethylarsenic peroxy radical [(CH3)2AsOO·], that are produced by the reaction of molecular oxygen and dimethylarsine [(CH3)2AsH], which is probably a further reductive metabolite of trivalent dimethylated arsenic, may be main agents for initiation in mouse lung tumorigenesis

  5. NMR-based characterization of metabolic alterations in hypertension using an adaptive, intelligent binning algorithm.

    De Meyer, Tim; Sinnaeve, Davy; Van Gasse, Bjorn; Tsiporkova, Elena; Rietzschel, Ernst R; De Buyzere, Marc L; Gillebert, Thierry C; Bekaert, Sofie; Martins, José C; Van Criekinge, Wim

    2008-05-15

    As with every -omics technology, metabolomics requires new methodologies for data processing. Due to the large spectral size, a standard approach in NMR-based metabolomics implies the division of spectra into equally sized bins, thereby simplifying subsequent data analysis. Yet, disadvantages are the loss of information and the occurrence of artifacts caused by peak shifts. Here, a new binning algorithm, Adaptive Intelligent Binning (AI-Binning), which largely circumvents these problems, is presented. AI-Binning recursively identifies bin edges in existing bins, requires only minimal user input, and avoids the use of arbitrary parameters or reference spectra. The performance of AI-Binning is demonstrated using serum spectra from 40 hypertensive and 40 matched normotensive subjects from the Asklepios study. Hypertension is a major cardiovascular risk factor characterized by a complex biochemistry and, in most cases, an unknown origin. The binning algorithm resulted in an improved classification of hypertensive status compared with that of standard binning and facilitated the identification of relevant metabolites. Moreover, since the occurrence of noise variables is largely avoided, AI-Binned spectra can be unit-variance scaled. This enables the detection of relevant, low-intensity metabolites. These results demonstrate the power of AI-Binning and suggest the involvement of alpha-1 acid glycoproteins and choline biochemistry in hypertension. PMID:18419139

  6. Differential effect of ultraviolet-B radiation on certain metabolic processes in a chromatically adapting Nostoc

    The impact of UV-B radiation on growth, pigmentation and certain physiological processes was studied in a N2-fixing chromatically adapting cyanobacterium, Nostoc spongiaeforme. A brownish form (phycoerythrin rich) was found to be more tolerant to UV-B than the blue-green (phycocyanin rich) form of N. spongiaeforme. Continuous exposure to UV-B (5.5 W m-2) for 90 min caused complete killing of the blue-green strain whereas the brown strain showed complete loss of survival after 180 min. Pigment content was more strongly inhibited in the blue-green strain than in the brown. Nitrogenase activity was completely abolished in both strains within 35 min of UV-B treatment. Restoration of nitrogenase occurred upon transfer to fluorescent or incandescent light after a lag of 5-6 h, suggesting fresh synthesis of nitrogenase. In vivo nitrate reductase activity was stimulated by UV-B treatment, the degree of enhancement being significantly higher in the blue-green strain. 14CO2 uptake was also completely abolished by UV-B treatment in both strains. (author)

  7. Metabolic engineering and adaptive evolution for efficient production of D-lactic acid in Saccharomyces cerevisiae.

    Baek, Seung-Ho; Kwon, Eunice Y; Kim, Yong Hwan; Hahn, Ji-Sook

    2016-03-01

    There is an increasing demand for microbial production of lactic acid (LA) as a monomer of biodegradable poly lactic acid (PLA). Both optical isomers, D-LA and L-LA, are required to produce stereocomplex PLA with improved properties. In this study, we developed Saccharomyces cerevisiae strains for efficient production of D-LA. D-LA production was achieved by expressing highly stereospecific D-lactate dehydrogenase gene (ldhA, LEUM_1756) from Leuconostoc mesenteroides subsp. mesenteroides ATCC 8293 in S. cerevisiae lacking natural LA production activity. D-LA consumption after glucose depletion was inhibited by deleting DLD1 encoding D-lactate dehydrogenase and JEN1 encoding monocarboxylate transporter. In addition, ethanol production was reduced by deleting PDC1 and ADH1 genes encoding major pyruvate decarboxylase and alcohol dehydrogenase, respectively, and glycerol production was eliminated by deleting GPD1 and GPD2 genes encoding glycerol-3-phosphate dehydrogenase. LA tolerance of the engineered D-LA-producing strain was enhanced by adaptive evolution and overexpression of HAA1 encoding a transcriptional activator involved in weak acid stress response, resulting in effective D-LA production up to 48.9 g/L without neutralization. In a flask fed-batch fermentation under neutralizing condition, our evolved strain produced 112.0 g/L D-LA with a yield of 0.80 g/g glucose and a productivity of 2.2 g/(L · h). PMID:26596574

  8. Differential effect of ultraviolet-B radiation on certain metabolic processes in a chromatically adapting Nostoc

    Tyagi, R.; Srinivas, G.; Vyas, D.; Kumar, A.; Kumar, H.D. (Banaras Hindu Univ., Varanasi (India))

    1992-03-01

    The impact of UV-B radiation on growth, pigmentation and certain physiological processes was studied in a N{sub 2}-fixing chromatically adapting cyanobacterium, Nostoc spongiaeforme. A brownish form (phycoerythrin rich) was found to be more tolerant to UV-B than the blue-green (phycocyanin rich) form of N. spongiaeforme. Continuous exposure to UV-B (5.5 W m{sup -2}) for 90 min caused complete killing of the blue-green strain whereas the brown strain showed complete loss of survival after 180 min. Pigment content was more strongly inhibited in the blue-green strain than in the brown. Nitrogenase activity was completely abolished in both strains within 35 min of UV-B treatment. Restoration of nitrogenase occurred upon transfer to fluorescent or incandescent light after a lag of 5-6 h, suggesting fresh synthesis of nitrogenase. In vivo nitrate reductase activity was stimulated by UV-B treatment, the degree of enhancement being significantly higher in the blue-green strain. {sup 14}CO{sub 2} uptake was also completely abolished by UV-B treatment in both strains. (author).

  9. Adaptive block-wise alphabet reduction scheme for lossless compression of images with sparse and locally sparse histograms

    Masmoudi, Atef; Zouari, Sonia; Ghribi, Abdelaziz

    2015-11-01

    We propose a new adaptive block-wise lossless image compression algorithm, which is based on the so-called alphabet reduction scheme combined with an adaptive arithmetic coding (AC). This new encoding algorithm is particularly efficient for lossless compression of images with sparse and locally sparse histograms. AC is a very efficient technique for lossless data compression and produces a rate that is close to the entropy; however, a compression performance loss occurs when encoding images or blocks with a limited number of active symbols by comparison with the number of symbols in the nominal alphabet, which consists in the amplification of the zero frequency problem. Generally, most methods add one to the frequency count of each symbol from the nominal alphabet, which leads to a statistical model distortion, and therefore reduces the efficiency of the AC. The aim of this work is to overcome this drawback by assigning to each image block the smallest possible set including all the existing symbols called active symbols. This is an alternative of using the nominal alphabet when applying the conventional arithmetic encoders. We show experimentally that the proposed method outperforms several lossless image compression encoders and standards including the conventional arithmetic encoders, JPEG2000, and JPEG-LS.

  10. How adaptable is the hydraulic system of European beech in the face of climate change-related precipitation reduction?

    Schuldt, Bernhard; Knutzen, Florian; Delzon, Sylvain; Jansen, Steven; Müller-Haubold, Hilmar; Burlett, Régis; Clough, Yann; Leuschner, Christoph

    2016-04-01

    Climate warming will increase the drought exposure of many forests world-wide. It is not well understood how trees adapt their hydraulic architecture to a long-term decrease in water availability. We examined 23 traits characterizing the hydraulic architecture and growth rate of branches and the dependent foliage of mature European beech (Fagus sylvatica) trees along a precipitation gradient (855-594 mm yr(-1) ) on uniform soil. A main goal was to identify traits that are associated with xylem efficiency, safety and growth. Our data demonstrate for the first time a linear increase in embolism resistance with climatic aridity (by 10%) across populations within a species. Simultaneously, vessel diameter declined by 7% and pit membrane thickness (Tm ) increased by 15%. Although specific conductivity did not change, leaf-specific conductivity declined by 40% with decreasing precipitation. Of eight plant traits commonly associated with embolism resistance, only vessel density in combination with pathway redundancy and Tm were related. We did not confirm the widely assumed trade-off between xylem safety and efficiency but obtained evidence in support of a positive relationship between hydraulic efficiency and growth. We conclude that the branch hydraulic system of beech has a distinct adaptive potential to respond to a precipitation reduction as a result of the environmental control of embolism resistance. PMID:26720626

  11. Complexity reduction in the H.264/AVC using highly adaptive fast mode decision based on macroblock motion activity

    Abdellah, Skoudarli; Mokhtar, Nibouche; Amina, Serir

    2015-11-01

    The H.264/AVC video coding standard is used in a wide range of applications from video conferencing to high-definition television according to its high compression efficiency. This efficiency is mainly acquired from the newly allowed prediction schemes including variable block modes. However, these schemes require a high complexity to select the optimal mode. Consequently, complexity reduction in the H.264/AVC encoder has recently become a very challenging task in the video compression domain, especially when implementing the encoder in real-time applications. Fast mode decision algorithms play an important role in reducing the overall complexity of the encoder. In this paper, we propose an adaptive fast intermode algorithm based on motion activity, temporal stationarity, and spatial homogeneity. This algorithm predicts the motion activity of the current macroblock from its neighboring blocks and identifies temporal stationary regions and spatially homogeneous regions using adaptive threshold values based on content video features. Extensive experimental work has been done in high profile, and results show that the proposed source-coding algorithm effectively reduces the computational complexity by 53.18% on average compared with the reference software encoder, while maintaining the high-coding efficiency of H.264/AVC by incurring only 0.097 dB in total peak signal-to-noise ratio and 0.228% increment on the total bit rate.

  12. Loss of CD24 in Mice Leads to Metabolic Dysfunctions and a Reduction in White Adipocyte Tissue.

    Nicholas A Fairbridge

    Full Text Available CD24 is a glycophosphatidylinositol (GPI-linked cell surface receptor that is involved in regulating the survival or differentiation of several different cell types. CD24 has been used to identify pre-adipocytes that are able to reconstitute white adipose tissue (WAT in vivo. Moreover, we recently found that the dynamic upregulation of CD24 in vitro during early phases of adipogenesis is necessary for mature adipocyte development. To determine the role of CD24 in adipocyte development in vivo, we evaluated the development of the inguinal and interscapular subcutaneous WAT and the epididymal visceral WAT in mice with a homozygous deletion of CD24 (CD24KO. We observed a significant decrease in WAT mass of 40% to 74% in WAT mass from both visceral and subcutaneous depots in male mice, with no significant effect in female mice, compared to wild-type (WT sex- and age-matched controls. We also found that CD24KO mice had increased fasting glucose and free fatty acids, decreased fasting insulin, and plasma leptin. No major differences were observed in the sensitivity to insulin or glucose, or in circulating triglycerides, total cholesterol, HDL-cholesterol, or LDL-cholesterol levels between WT and CD24KO mice. Challenging the CD24KO mice with either high sucrose (35% or high fat (45% diets that promote increased adiposity, increased WAT mass and fasting insulin, adiponectin and leptin levels, as well as reduced the sensitivity to insulin and glucose, to the levels of WT mice on the same diets. The CD24-mediated reduction in fat pad size was due to a reduction in adipocyte cell size in all depots with no significant reduction pre-adipocyte or adipocyte cell number. Thus, we have clearly demonstrated that the global absence of CD24 affects adipocyte cell size in vivo in a sex- and diet-dependent manner, as well as causing metabolic disturbances in glucose homeostasis and free fatty acid levels.

  13. Adaptive grid artifact reduction in the frequency domain with spatial properties for x-ray images

    Kim, Dong Sik; Lee, Sanggyun

    2012-03-01

    By applying band-rejection filters (BRFs) in the frequency domain, we can efficiently reduce the grid artifacts, which are caused by using the antiscatter grid in obtaining x-ray digital images. However, if the frequency component of the grid artifact is relatively close to that of the object, then simply applying a BRF may seriously distort the object and cause the ringing artifacts. Since the ringing artifacts are quite dependent on the shape of the object to be recovered in the spatial domain, the spatial property of the x-ray image should be considered in applying BRFs. In this paper, we propose an adaptive filtering scheme, which can cooperate such different properties in the spatial domain. In the spatial domain, we compare several approaches, such as the mangnitude, edge, and frequency-modulation (FM) model-based algorithms, to detect the ringing artifact or the grid artifact component. In order to perform a robust detection whether the ringing artifact is strong or not, we employ the FM model for the extracted signal, which corresponds to a specific grid artifact. A detection of the position for the ringing artifact is then conducted based on the slope detection algorithm, which is commonly used as an FM discriminator in the communication area. However, the detected position of the ringing artifact is not accurate. Hence, in order to obtain an accurate detection result, we combine the edge-based approach with the FM model approach. Numerical result for real x-ray images shows that applying BRFs in the frequency domain in conjunction with the spatial property of the ringing artifact can successfully remove the grid artifact, distorting the object less.

  14. Bandwidth reduction of high-frequency sonar imagery in shallow water using content-adaptive hybrid image coding

    Shin, Frances B.; Kil, David H.

    1998-09-01

    One of the biggest challenges in distributed underwater mine warfare for area sanitization and safe power projection during regional conflicts is transmission of compressed raw imagery data to a central processing station via a limited bandwidth channel while preserving crucial target information for further detection and automatic target recognition processing. Moreover, operating in an extremely shallow water with fluctuating channels and numerous interfering sources makes it imperative that image compression algorithms effectively deal with background nonstationarity within an image as well as content variation between images. In this paper, we present a novel approach to lossy image compression that combines image- content classification, content-adaptive bit allocation, and hybrid wavelet tree-based coding for over 100:1 bandwidth reduction with little sacrifice in signal-to-noise ratio (SNR). Our algorithm comprises (1) content-adaptive coding that takes advantage of a classify-before-coding strategy to reduce data mismatch, (2) subimage transformation for energy compaction, and (3) a wavelet tree-based coding for efficient encoding of significant wavelet coefficients. Furthermore, instead of using the embedded zerotree coding with scalar quantization (SQ), we investigate the use of a hybrid coding strategy that combines SQ for high-magnitude outlier transform coefficients and classified vector quantization (CVQ) for compactly clustered coefficients. This approach helps us achieve reduced distortion error and robustness while achieving high compression ratio. Our analysis based on the high-frequency sonar real data that exhibit severe content variability and contain both mines and mine-like clutter indicates that we can achieve over 100:1 compression ratio without losing crucial signal attributes. In comparison, benchmarking of the same data set with the best still-picture compression algorithm called the set partitioning in hierarchical trees (SPIHT) reveals

  15. Changes in C-N metabolism under elevated CO2 and temperature in Indian mustard (Brassica juncea L.): an adaptation strategy under climate change scenario.

    Seth, Chandra Shekhar; Misra, Virendra

    2014-11-01

    The present study was performed to investigate the possible role of carbon (C) and nitrogen (N) metabolism in adaptation of Indian mustard (Brassica juncea L.) growing under ambient (370 ± 15 ppm) and elevated CO2 (700 ± 15 ppm), and jointly in elevated CO2 and temperature (30/22 °C for day/night). The key enzymes responsible for C-N metabolism were studied in different samples of Brassica juncea L. collected from ambient (AMB), elevated (ELE) and ELExT growth conditions. Total percent amount of C and N in leaves were particularly estimated to establish a clear understanding of aforesaid metabolism in plant adaptation. Furthermore, key morphological and physiological parameters such as plant height, leaf area index, dry biomass, net photosynthetic rate, stomatal conductance, transpiration, total protein and chlorophyll contents were also studied in relation to C/N metabolism. The results indicated that the C-metabolizing enzymes, such as (ribulose-1,5-bisphosphate carboxylase/oxygenase, phosphoenolpyruvate carboxylase, malate dehydrogenase, NAD-malic enzyme, NADP-malic enzyme and citrate synthase) and the N-metabolizing enzymes, such as (aspartate amino transferase, glutamine synthetase, nitrate reductase and nitrite reductase) showed significantly (P ELE > ELExT > AMB growth conditions. This is also evident by significant (P < 0.05) increase in percent contents of C and N in leaves as per said order. These findings suggested that improved performance of C-N metabolism could be a possible approach for CO2 assimilation and adaptation in Brassica juncea L. against elevated CO2 and temperature prevailing in climate change scenarios. PMID:25246072

  16. A Generalized Learning Curve Adapted for Purchasing and Cost Reduction Negotiations

    Lam F. Wong

    2013-01-01

    Full Text Available This paper presents the use and validation of a generalized learning curve in the economies of scale purchasing experience. The model, based on Wright’s curve, incorporates two extra degrees of freedom to accommodate initial purchases of multiple (instead of single units and a finite asymptotic price at high volumes. The study shows that each time the part purchase quantity is doubled, the price is reduced either by a constant percentage (a learning rate or by an approach to an asymptotic plateau rate indicating a point of diminishing returns. Supplier price quotations at multiple purchase quantities were obtained for a pool of 17 critical parts. The data were fitted with the generalized learning curve by the method of least squares regression. The regressed learning rate, first unit price, and the asymptotic price can be used to infer supplier pricing strategies. Coupled with a “should-cost” analysis based on estimates of standard time and material, a system cost reduction task was carried out by the supply chain organization.

  17. The Variable Regions of Lactobacillus rhamnosus Genomes Reveal the Dynamic Evolution of Metabolic and Host-Adaptation Repertoires.

    Ceapa, Corina; Davids, Mark; Ritari, Jarmo; Lambert, Jolanda; Wels, Michiel; Douillard, François P; Smokvina, Tamara; de Vos, Willem M; Knol, Jan; Kleerebezem, Michiel

    2016-01-01

    Lactobacillus rhamnosus is a diverse Gram-positive species with strains isolated from different ecological niches. Here, we report the genome sequence analysis of 40 diverse strains of L. rhamnosus and their genomic comparison, with a focus on the variable genome. Genomic comparison of 40 L. rhamnosus strains discriminated the conserved genes (core genome) and regions of plasticity involving frequent rearrangements and horizontal transfer (variome). The L. rhamnosus core genome encompasses 2,164 genes, out of 4,711 genes in total (the pan-genome). The accessory genome is dominated by genes encoding carbohydrate transport and metabolism, extracellular polysaccharides (EPS) biosynthesis, bacteriocin production, pili production, the cas system, and the associated clustered regularly interspaced short palindromic repeat (CRISPR) loci, and more than 100 transporter functions and mobile genetic elements like phages, plasmid genes, and transposons. A clade distribution based on amino acid differences between core (shared) proteins matched with the clade distribution obtained from the presence-absence of variable genes. The phylogenetic and variome tree overlap indicated that frequent events of gene acquisition and loss dominated the evolutionary segregation of the strains within this species, which is paralleled by evolutionary diversification of core gene functions. The CRISPR-Cas system could have contributed to this evolutionary segregation. Lactobacillus rhamnosus strains contain the genetic and metabolic machinery with strain-specific gene functions required to adapt to a large range of environments. A remarkable congruency of the evolutionary relatedness of the strains' core and variome functions, possibly favoring interspecies genetic exchanges, underlines the importance of gene-acquisition and loss within the L. rhamnosus strain diversification. PMID:27358423

  18. An adaptive integrated algorithm for noninvasive fetal ECG separation and noise reduction based on ICA-EEMD-WS.

    Liu, Guangchen; Luan, Yihui

    2015-11-01

    High-resolution fetal electrocardiogram (FECG) plays an important role in assisting physicians to detect fetal changes in the womb and to make clinical decisions. However, in real situations, clear FECG is difficult to extract because it is usually overwhelmed by the dominant maternal ECG and other contaminated noise such as baseline wander, high-frequency noise. In this paper, we proposed a novel integrated adaptive algorithm based on independent component analysis (ICA), ensemble empirical mode decomposition (EEMD), and wavelet shrinkage (WS) denoising, denoted as ICA-EEMD-WS, for FECG separation and noise reduction. First, ICA algorithm was used to separate the mixed abdominal ECG signal and to obtain the noisy FECG. Second, the noise in FECG was reduced by a three-step integrated algorithm comprised of EEMD, useful subcomponents statistical inference and WS processing, and partial reconstruction for baseline wander reduction. Finally, we evaluate the proposed algorithm using simulated data sets. The results indicated that the proposed ICA-EEMD-WS outperformed the conventional algorithms in signal denoising. PMID:26429348

  19. Review Article: "Adaptive governance and resilience: the role of multi-stakeholder platforms in disaster risk reduction"

    R. Djalante

    2012-09-01

    Full Text Available Disaster impacts are more frequent, deadly and costly. The social and environmental consequences are increasingly complex and intertwined. Systematic as well as innovated strategies are needed to manage the impacts. Disaster Risk Reduction (DRR is a systematic approach to manage disaster risks while adaptive governance (AG is suggested as an alternative approach for governing complex problems such as disasters. The author proposes that the AG can be practicalised through a mechanism of multi-stakeholder platforms (MSPs, interpreted as multiplicity of organisations at different scales of governance working towards more coordinated and integrated actions in DRR. Ten MSPs are selected at the global, regional, national and local level, focussing on the Indonesian MSPs. The literature reviews and in-depth interviews with key respondents in Indonesia show that the international and regional MSPs tend to have more human, technical and financial capacity than national and local MSPs. The author finds that most MSP roles focus on the coordination amongst multitudes of organisations. Only those MSPs that are able to generate new funding have the capacity to implement direct risk reduction activities. The development of the MSP is highly influenced by the UNISDR system operating at different levels. Particularly in Indonesia, MSP are also influenced by the operations of various UN and international organisations. Finally, the paper suggests the need for more provision of technical supports to local MSPs, more linkages with established networks in DRR and broader stakeholders involvement within the MSPs.

  20. Review Article: "Adaptive governance and resilience: the role of multi-stakeholder platforms in disaster risk reduction"

    Djalante, R.

    2012-09-01

    Disaster impacts are more frequent, deadly and costly. The social and environmental consequences are increasingly complex and intertwined. Systematic as well as innovated strategies are needed to manage the impacts. Disaster Risk Reduction (DRR) is a systematic approach to manage disaster risks while adaptive governance (AG) is suggested as an alternative approach for governing complex problems such as disasters. The author proposes that the AG can be practicalised through a mechanism of multi-stakeholder platforms (MSPs), interpreted as multiplicity of organisations at different scales of governance working towards more coordinated and integrated actions in DRR. Ten MSPs are selected at the global, regional, national and local level, focussing on the Indonesian MSPs. The literature reviews and in-depth interviews with key respondents in Indonesia show that the international and regional MSPs tend to have more human, technical and financial capacity than national and local MSPs. The author finds that most MSP roles focus on the coordination amongst multitudes of organisations. Only those MSPs that are able to generate new funding have the capacity to implement direct risk reduction activities. The development of the MSP is highly influenced by the UNISDR system operating at different levels. Particularly in Indonesia, MSP are also influenced by the operations of various UN and international organisations. Finally, the paper suggests the need for more provision of technical supports to local MSPs, more linkages with established networks in DRR and broader stakeholders involvement within the MSPs.

  1. Razor clam to RoboClam: burrowing drag reduction mechanisms and their robotic adaptation

    Estimates based on the strength, size, and shape of the Atlantic razor clam (Ensis directus) indicate that the animal's burrow depth should be physically limited to a few centimeters; yet razor clams can dig as deep as 70 cm. By measuring soil deformations around burrowing E. directus, we have found the animal reduces drag by contracting its valves to initially fail, and then fluidize, the surrounding substrate. The characteristic contraction time to achieve fluidization can be calculated directly from soil properties. The geometry of the fluidized zone is dictated by two commonly-measured geotechnical parameters: coefficient of lateral earth pressure and friction angle. Calculations using full ranges for both parameters indicate that the fluidized zone is a local effect, occurring between 1–5 body radii away from the animal. The energy associated with motion through fluidized substrate—characterized by a depth-independent density and viscosity—scales linearly with depth. In contrast, moving through static soil requires energy that scales with depth squared. For E. directus, this translates to a 10X reduction in the energy required to reach observed burrow depths. For engineers, localized fluidization offers a mechanically simple and purely kinematic method to dramatically reduce energy costs associated with digging. This concept is demonstrated with RoboClam, an E. directus-inspired robot. Using a genetic algorithm to find optimal digging kinematics, RoboClam has achieved localized fluidization burrowing performance comparable to that of the animal, with a linear energy-depth relationship, in both idealized granular glass beads and E. directus' native cohesive mudflat habitat. (paper)

  2. Effects of adaptive statistical iterative reconstruction on radiation dose reduction and diagnostic accuracy of pediatric abdominal CT

    Since children are more radio-sensitive than adults, there is a need to minimize radiation exposure during CT exams. To evaluate the effects of adaptive statistical iterative reconstruction (ASIR) on radiation dose reduction, image quality and diagnostic accuracy in pediatric abdominal CT. We retrospectively reviewed the abdominal CT examinations of 41 children (24 boys and 17 girls; mean age: 10 years) with a low-dose radiation protocol and reconstructed with ASIR (the ASIR group). We also reviewed routine-dose abdominal CT examinations of 41 age- and sex-matched controls reconstructed with filtered-back projection (control group). Image quality was assessed objectively as noise measured in the liver, spleen and aorta, as well as subjectively by three pediatric radiologists for diagnostic acceptability using a four-point scale. Radiation dose and objective image qualities of each group were compared with the paired t-test. Diagnostic accuracy was evaluated by reviewing follow-up imaging studies and medical records in 2012 and 2013. There was 46.3% dose reduction of size-specific dose estimates in ASIR group (from 13.4 to 7.2 mGy) compared with the control group. Objective noise was higher in the liver, spleen and aorta of the ASIR group (P < 0.001). However, the subjective image quality was average or superior in 84-100% of studies. Only one image was subjectively rated as unacceptable by one reviewer. There was only one case with interpretational error in the control group and none in the ASIR group. Use of the ASIR technique resulted in greater than a 45% reduction in radiation dose without impairing subjective image quality or diagnostic accuracy in pediatric abdominal CT, despite increased objective image noise. (orig.)

  3. Effects of adaptive statistical iterative reconstruction on radiation dose reduction and diagnostic accuracy of pediatric abdominal CT

    Bae, Sohi; Kim, Myung-Joon; Lee, Mi-Jung [Yonsei University College of Medicine, Department of Radiology and Research Institute of Radiological Science, Severance Children' s Hospital, Seoul (Korea, Republic of); Yoon, Choon-Sik [Yonsei University College of Medicine, Department of Radiology, Gangnam Severance Hospital, Seoul (Korea, Republic of); Kim, Dong Wook; Hong, Jung Hwa [Yonsei University College of Medicine, Biostatistics Collaboration Unit, Seoul (Korea, Republic of)

    2014-12-15

    Since children are more radio-sensitive than adults, there is a need to minimize radiation exposure during CT exams. To evaluate the effects of adaptive statistical iterative reconstruction (ASIR) on radiation dose reduction, image quality and diagnostic accuracy in pediatric abdominal CT. We retrospectively reviewed the abdominal CT examinations of 41 children (24 boys and 17 girls; mean age: 10 years) with a low-dose radiation protocol and reconstructed with ASIR (the ASIR group). We also reviewed routine-dose abdominal CT examinations of 41 age- and sex-matched controls reconstructed with filtered-back projection (control group). Image quality was assessed objectively as noise measured in the liver, spleen and aorta, as well as subjectively by three pediatric radiologists for diagnostic acceptability using a four-point scale. Radiation dose and objective image qualities of each group were compared with the paired t-test. Diagnostic accuracy was evaluated by reviewing follow-up imaging studies and medical records in 2012 and 2013. There was 46.3% dose reduction of size-specific dose estimates in ASIR group (from 13.4 to 7.2 mGy) compared with the control group. Objective noise was higher in the liver, spleen and aorta of the ASIR group (P < 0.001). However, the subjective image quality was average or superior in 84-100% of studies. Only one image was subjectively rated as unacceptable by one reviewer. There was only one case with interpretational error in the control group and none in the ASIR group. Use of the ASIR technique resulted in greater than a 45% reduction in radiation dose without impairing subjective image quality or diagnostic accuracy in pediatric abdominal CT, despite increased objective image noise. (orig.)

  4. A study on statistical parametric mapping and PET for the metabolism reduction of Alzheimer's disease with different severity

    Objective Along with more clinical application of 18F-fourodeoxyglucose (FDG) PET, statistical parametric mapping (SPM) had attracted a lot of attention in past few years. The purpose of this study was to investigate the regional cerebral glucose metabolism changes in Alzheimer's disease (AD) patients with different stages by PET and SPM, according to the k value of the SPM result. Methods: Twenty-seven patients with AD according to diagnostic and statistical manual of mental disorders, 4th edition, revised (DSM-IV-R) and 9 healthy persons as the contrast were examined with three-dimensional (3D) 18F- FDG PET brain imaging about 40 min post-injection of 3.7 MBq/kg 18F-FDG and mini-mental state examination (MMSE) evaluation. The 27 AD patients were divided into 3 groups based on their MMSE scores: mild group with the score more than or equal to 20 but less than 25, moderate group with the score between 10 and 20 ( not including 10 and 20), and severe group with the score less than or equal to 10. All the contrast subjects' MMSE scores were more than or equal to 25. On the base of Matlab 6.5, all of the PET images with SPM were normalized and smoothed. A statistical model was established, and the whole AD patients were compared with the contrast group. And then the 3 AD groups were compared with the contrast group respectively. The localization and the k value of the activated region was gotten at last. Results: Compared with the healthy group, the most significant metabolic decrease area was in bilateral frontal lobe, parietal lobe, temporal lobe, post cingulate area and precuneus in AD group. The k value of the mild, moderate and severe group was 929, 6743 and 24 678 in order, while the k value of the frontal lobe was 174, 2712 and 4981 in order. Conclusions: SPM can be used in evaluating the extension of the regional cerebral glucose metabolism decrease according to the k value. The reduction degree becomes severely along with the progress stages of dementia

  5. Anthracycline resistance mediated by reductive metabolism in cancer cells: The role of aldo-keto reductase 1C3

    Hofman, Jakub; Malcekova, Beata; Skarka, Adam; Novotna, Eva; Wsol, Vladimir, E-mail: wsol@faf.cuni.cz

    2014-08-01

    Pharmacokinetic drug resistance is a serious obstacle that emerges during cancer chemotherapy. In this study, we investigated the possible role of aldo-keto reductase 1C3 (AKR1C3) in the resistance of cancer cells to anthracyclines. First, the reducing activity of AKR1C3 toward anthracyclines was tested using incubations with a purified recombinant enzyme. Furthermore, the intracellular reduction of daunorubicin and idarubicin was examined by employing the transfection of A549, HeLa, MCF7 and HCT 116 cancer cells with an AKR1C3 encoding vector. To investigate the participation of AKR1C3 in anthracycline resistance, we conducted MTT cytotoxicity assays with these cells, and observed that AKR1C3 significantly contributes to the resistance of cancer cells to daunorubicin and idarubicin, whereas this resistance was reversible by the simultaneous administration of 2′-hydroxyflavanone, a specific AKR1C3 inhibitor. In the final part of our work, we tracked the changes in AKR1C3 expression after anthracycline exposure. Interestingly, a reciprocal correlation between the extent of induction and endogenous levels of AKR1C3 was recorded in particular cell lines. Therefore, we suggest that the induction of AKR1C3 following exposure to daunorubicin and idarubicin, which seems to be dependent on endogenous AKR1C3 expression, eventually might potentiate an intrinsic resistance given by the normal expression of AKR1C3. In conclusion, our data suggest a substantial impact of AKR1C3 on the metabolism of daunorubicin and idarubicin, which affects their pharmacokinetic and pharmacodynamic behavior. In addition, we demonstrate that the reduction of daunorubicin and idarubicin, which is catalyzed by AKR1C3, contributes to the resistance of cancer cells to anthracycline treatment. - Highlights: • Metabolism of anthracyclines by AKR1C3 was studied at enzyme and cellular levels. • Anthracycline resistance mediated by AKR1C3 was demonstrated in cancer cells. • Induction of AKR1C3

  6. Anthracycline resistance mediated by reductive metabolism in cancer cells: The role of aldo-keto reductase 1C3

    Pharmacokinetic drug resistance is a serious obstacle that emerges during cancer chemotherapy. In this study, we investigated the possible role of aldo-keto reductase 1C3 (AKR1C3) in the resistance of cancer cells to anthracyclines. First, the reducing activity of AKR1C3 toward anthracyclines was tested using incubations with a purified recombinant enzyme. Furthermore, the intracellular reduction of daunorubicin and idarubicin was examined by employing the transfection of A549, HeLa, MCF7 and HCT 116 cancer cells with an AKR1C3 encoding vector. To investigate the participation of AKR1C3 in anthracycline resistance, we conducted MTT cytotoxicity assays with these cells, and observed that AKR1C3 significantly contributes to the resistance of cancer cells to daunorubicin and idarubicin, whereas this resistance was reversible by the simultaneous administration of 2′-hydroxyflavanone, a specific AKR1C3 inhibitor. In the final part of our work, we tracked the changes in AKR1C3 expression after anthracycline exposure. Interestingly, a reciprocal correlation between the extent of induction and endogenous levels of AKR1C3 was recorded in particular cell lines. Therefore, we suggest that the induction of AKR1C3 following exposure to daunorubicin and idarubicin, which seems to be dependent on endogenous AKR1C3 expression, eventually might potentiate an intrinsic resistance given by the normal expression of AKR1C3. In conclusion, our data suggest a substantial impact of AKR1C3 on the metabolism of daunorubicin and idarubicin, which affects their pharmacokinetic and pharmacodynamic behavior. In addition, we demonstrate that the reduction of daunorubicin and idarubicin, which is catalyzed by AKR1C3, contributes to the resistance of cancer cells to anthracycline treatment. - Highlights: • Metabolism of anthracyclines by AKR1C3 was studied at enzyme and cellular levels. • Anthracycline resistance mediated by AKR1C3 was demonstrated in cancer cells. • Induction of AKR1C3

  7. Intrinsic and Tumor Microenvironment-Induced Metabolism Adaptations of T Cells and Impact on Their Differentiation and Function

    Kouidhi, Soumaya; Noman, Muhammad Zaeem; Kieda, Claudine; Elgaaied, Amel Benammar; Chouaib, Salem

    2016-01-01

    It is well recognized that the immune system and metabolism are highly integrated. In this context, multilevel interactions between metabolic system and T lymphocyte signaling and fate exist. This review will discuss different potential cell metabolism pathways involved in shaping T lymphocyte function and differentiation. We will also provide a general framework for understanding how tumor microenvironmental metabolism, associated with hypoxic stress, interferes with T-cell priming and expansion. How T-cell metabolism drives T-cell-mediated immunity and how the manipulation of metabolic programing for therapeutic purposes will be also discussed. PMID:27066006

  8. Dynamic self-adaptive ANP algorithm and its application to electric field simulation of aluminum reduction cell

    王雅琳; 陈冬冬; 陈晓方; 蔡国民; 阳春华

    2015-01-01

    Region partition (RP) is the key technique to the finite element parallel computing (FEPC), and its performance has a decisive influence on the entire process of analysis and computation. The performance evaluation index of RP method for the three-dimensional finite element model (FEM) has been given. By taking the electric field of aluminum reduction cell (ARC) as the research object, the performance of two classical RP methods, which are Al-NASRA and NGUYEN partition (ANP) algorithm and the multi-level partition (MLP) method, has been analyzed and compared. The comparison results indicate a sound performance of ANP algorithm, but to large-scale models, the computing time of ANP algorithm increases notably. This is because the ANP algorithm determines only one node based on the minimum weight and just adds the elements connected to the node into the sub-region during each iteration. To obtain the satisfied speed and the precision, an improved dynamic self-adaptive ANP (DSA-ANP) algorithm has been proposed. With consideration of model scale, complexity and sub-RP stage, the improved algorithm adaptively determines the number of nodes and selects those nodes with small enough weight, and then dynamically adds these connected elements. The proposed algorithm has been applied to the finite element analysis (FEA) of the electric field simulation of ARC. Compared with the traditional ANP algorithm, the computational efficiency of the proposed algorithm has been shortened approximately from 260 s to 13 s. This proves the superiority of the improved algorithm on computing time performance.

  9. Possible Association of High Urinary Magnesium and Taurine to Creatinine Ratios with Metabolic Syndrome Risk Reduction in Australian Aboriginals

    Atsumi Hamada

    2011-01-01

    Full Text Available Background. Because of the epidemic of metabolic syndrome (MS in Australian Aboriginals known for their higher cardiovascular mortality and shorter life expectancy, we analyzed the possible relationship of their MS risks with the current dietary custom. Methods. The subjects were 84 people aged 16–79 years. The health examination was conducted according to the basic protocol of WHO-CARDIAC (Cardiovascular Diseases and Alimentary Comparison Study. Results. The highest prevalence among MS risks was abdominal obesity (over 60%. After controlling for age and sex, the odds of obesity decreased significantly with high level of urinary magnesium/creatinine ratio (Mg/cre (OR, 0.11; 95% CI, 0.02–0.57; P<.05. The significant inverse associations of fat intake with Mg/cre and of fast food intake with urinary taurine/creatinine ratio were revealed. Conclusions. The high prevalence of obesity in the Aboriginal people of this area may partly be due to the reduction of beneficial nutrients intake including Mg and taurine.

  10. Effects of ganglioside GM1 on reduction of brain edema and amelioration of cerebral metabolism after traumatic brain injury

    陈志刚; 卢亦成; 朱诚; 张光霁; 丁学华; 江基尧

    2003-01-01

    Objective: To observe the effects of ganglioside GM1 on reduction of brain edema and amelioration of cerebral metabolism after traumatic brain injury (TBI).Methods: An acute experimental closed TBI model in rats was induced by a fluid-percussion brain injury model. At five and sixty minutes after TBI, the animals were intraperitoneally injected by ganglioside GM1 (30 mg/kg) or the same volume of saline. At the 6th hour after TBI, effects of ganglioside GM1 or saline on changes of mean arterial pressure (MAP), contents of water, lactic acid (LA) and lipid peroxidation (LPO) in the injured cerebral tissues were observed.Results: After TBI, MAP decreased and contents of water, LA and LPO increased in brain injury group; however, MAP was back to normal levels and contents of water, LA and LPO decreased in ganglioside GM1 treated group, compared with those in brain injury group (P0.05) was observed.Conclusions: Ganglioside GM1 does have obvious neuroprotective effect on early TBI.