WorldWideScience

Sample records for underlying molecular level

  1. Single Molecular Level Probing of Structure and Dynamics of Papain Under Denaturation.

    Science.gov (United States)

    Sengupta, Bhaswati; Chaudhury, Apala; Das, Nilimesh; Sen, Pratik

    2017-01-01

    Papain is a cysteine protease enzyme present in papaya and known to help in digesting peptide. Thus the structure and function of the active site of papain is of interest. The objective of present study is to unveil the overall structural transformation and the local structural change around the active site of papain as a function of chemical denaturant. Papain has been tagged at Cys-25 with a thiol specific fluorescence probe N-(7- dimethylamino-4-methylcoumarin-3-yl) iodoacetamide (DACIA). Guanidine hydrochloride (GnHCl) has been used as the chemical denaturant. Steady state, time-resolved, and single molecular level fluorescence techniques was applied to map the change in the local environment. It is found that papain undergoes a two-step denaturation in the presence of GnHCl. Fluorescence correlation spectroscopic (FCS) data indicate that the size (hydrodynamic diameter) of native papain is ~36.8 Å, which steadily increases to ~53 Å in the presence of 6M GnHCl. FCS study also reveals that the conformational fluctuation time of papain is 6.3 µs in its native state, which decreased to 2.7 µs in the presence of 0.75 M GnHCl. Upon further increase in GnHCl concentration the conformational fluctuation time increase monotonically till 6 M GnHCl, where the time constant is measured as 14 µs. On the other hand, the measurement of ellipticity, hence the helical structure, by circular dichroism spectroscopy is found to be incapable to capture such structural transformation. It is concluded that in the presence of small amount of GnHCl the active site of papain takes up a more compact structure (although the overall size increases) than in the native state, which has been designated as the intermediate state. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  2. Molecular changes underlying reduced pineal melatonin levels in Alzheimer disease: alterations in preclinical and clinical stages

    NARCIS (Netherlands)

    Wu, Ying-Hui; Feenstra, Matthijs G. P.; Zhou, Jiang-Ning; Liu, Rong-Yu; Toranõ, Javier Sastre; van Kan, Hendrikus J. M.; Fischer, David F.; Ravid, Rivka; Swaab, Dick F.

    2003-01-01

    A disturbed sleep-wake rhythm is common in Alzheimer disease (AD) patients and correlated with decreased melatonin levels and a disrupted circadian melatonin rhythm. Melatonin levels in the cerebrospinal fluid are decreased during the progression of AD neuropathology (as determined by the Braak

  3. Molecular mechanisms underlying bacterial persisters

    DEFF Research Database (Denmark)

    Maisonneuve, Etienne; Gerdes, Kenn

    2014-01-01

    All bacteria form persisters, cells that are multidrug tolerant and therefore able to survive antibiotic treatment. Due to the low frequencies of persisters in growing bacterial cultures and the complex underlying molecular mechanisms, the phenomenon has been challenging to study. However, recent...

  4. Molecular evolution under fitness fluctuations.

    Science.gov (United States)

    Mustonen, Ville; Lässig, Michael

    2008-03-14

    Molecular evolution is a stochastic process governed by fitness, mutations, and reproductive fluctuations in a population. Here, we study evolution where fitness itself is stochastic, with random switches in the direction of selection at individual genomic loci. As the correlation time of these fluctuations becomes larger than the diffusion time of mutations within the population, fitness changes from an annealed to a quenched random variable. We show that the rate of evolution has its maximum in the crossover regime, where both time scales are comparable. Adaptive evolution emerges in the quenched fitness regime (evidence for such fitness fluctuations has recently been found in genomic data). The joint statistical theory of reproductive and fitness fluctuations establishes a conceptual connection between evolutionary genetics and statistical physics of disordered systems.

  5. Evolution of molecular phenotypes under stabilizing selection

    Science.gov (United States)

    Nourmohammad, Armita; Schiffels, Stephan; Lässig, Michael

    2013-01-01

    Molecular phenotypes are important links between genomic information and organismic functions, fitness, and evolution. Complex phenotypes, which are also called quantitative traits, often depend on multiple genomic loci. Their evolution builds on genome evolution in a complicated way, which involves selection, genetic drift, mutations and recombination. Here we develop a coarse-grained evolutionary statistics for phenotypes, which decouples from details of the underlying genotypes. We derive approximate evolution equations for the distribution of phenotype values within and across populations. This dynamics covers evolutionary processes at high and low recombination rates, that is, it applies to sexual and asexual populations. In a fitness landscape with a single optimal phenotype value, the phenotypic diversity within populations and the divergence between populations reach evolutionary equilibria, which describe stabilizing selection. We compute the equilibrium distributions of both quantities analytically and we show that the ratio of mean divergence and diversity depends on the strength of selection in a universal way: it is largely independent of the phenotype’s genomic encoding and of the recombination rate. This establishes a new method for the inference of selection on molecular phenotypes beyond the genome level. We discuss the implications of our findings for the predictability of evolutionary processes.

  6. Evolution of molecular phenotypes under stabilizing selection

    International Nuclear Information System (INIS)

    Nourmohammad, Armita; Schiffels, Stephan; Lässig, Michael

    2013-01-01

    Molecular phenotypes are important links between genomic information and organismic functions, fitness, and evolution. Complex phenotypes, which are also called quantitative traits, often depend on multiple genomic loci. Their evolution builds on genome evolution in a complicated way, which involves selection, genetic drift, mutations and recombination. Here we develop a coarse-grained evolutionary statistics for phenotypes, which decouples from details of the underlying genotypes. We derive approximate evolution equations for the distribution of phenotype values within and across populations. This dynamics covers evolutionary processes at high and low recombination rates, that is, it applies to sexual and asexual populations. In a fitness landscape with a single optimal phenotype value, the phenotypic diversity within populations and the divergence between populations reach evolutionary equilibria, which describe stabilizing selection. We compute the equilibrium distributions of both quantities analytically and we show that the ratio of mean divergence and diversity depends on the strength of selection in a universal way: it is largely independent of the phenotype’s genomic encoding and of the recombination rate. This establishes a new method for the inference of selection on molecular phenotypes beyond the genome level. We discuss the implications of our findings for the predictability of evolutionary processes. (paper)

  7. Molecular Signatures Underlying Synaptic Vesicle Cargo Retrieval

    Science.gov (United States)

    Mori, Yasunori; Takamori, Shigeo

    2018-01-01

    Efficient retrieval of the synaptic vesicle (SV) membrane from the presynaptic plasma membrane, a process called endocytosis, is crucial for the fidelity of neurotransmission, particularly during sustained neural activity. Although multiple modes of endocytosis have been identified, it is clear that the efficient retrieval of the major SV cargos into newly formed SVs during any of these modes is fundamental for synaptic transmission. It is currently believed that SVs are eventually reformed via a clathrin-dependent pathway. Various adaptor proteins recognize SV cargos and link them to clathrin, ensuring the efficient retrieval of the cargos into newly formed SVs. Here, we summarize our current knowledge of the molecular signatures within individual SV cargos that underlie efficient retrieval into SV membranes, as well as discuss possible contributions of the mechanisms under physiological conditions. PMID:29379416

  8. A photochemically driven molecular-level abacus

    Science.gov (United States)

    Ashton; Ballardini; Balzani; Credi; Dress; Ishow; Kleverlaan; Kocian; Preece; Spencer; Stoddart; Venturi; Wenger

    2000-10-02

    A molecular-level abacus-like system driven by light inputs has been designed in the form of a [2]rotaxane, comprising the pi-electron-donating macrocyclic polyether bis-p-phenylene-34-crown-10 (BPP34C10) and a dumbbell-shaped component that contains 1) a Ru(II) polypyridine complex as one of its stoppers in the form of a photoactive unit, 2) a p-terphenyl-type ring system as a rigid spacer, 3) a 4,4'-bipyridinium unit and a 3,3'-dimethyl-4,4'-bipyridinium unit as pi-electron-accepting stations, and 4) a tetraarylmethane group as the second stopper. The synthesis of the [2]rotaxane was accomplished in four successive stages. First of all, the dumbbell-shaped component of the [2]rotaxane was constructed by using conventional synthetic methodology to make 1) the so-called "west-side" comprised of the Ru(II) polypyridine complex linked by a bismethylene spacer to the p-terphenyl-type ring system terminated by a benzylic bromomethyl function and 2) the so-called "east-side" comprised of the tetraarylmethane group, attached by a polyether linkage to the bipyridinium unit, itself joined in turn by a trismethylene spacer to an incipient 3,3'-dimethyl-4,4'-bipyridinium unit. Next, 3) the "west-side" and "east-side" were fused together by means of an alkylation to give the dumbbell-shaped compound, which was 4) finally subjected to a thermodynamically driven slippage reaction, with BPP34C10 as the ring, to afford the [2]rotaxane. The structure of this interlocked molecular compound was characterized by mass spectrometry and NMR spectroscopy, which also established, along with cyclic voltammetry, the co-conformational behavior of the molecular shuttle. The stable translational isomer is the one in which the BPP34C10 component encircles the 4,4'-bipyridinium unit, in keeping with the fact that this station is a better pi-electron acceptor than the other station. This observation raises the question- can the BPP34C10 macrocycle be made to shuttle between the two stations by a

  9. Proteoglycans remodeling in cancer: Underlying molecular mechanisms.

    Science.gov (United States)

    Theocharis, Achilleas D; Karamanos, Nikos K

    2017-11-08

    Extracellular matrix is a highly dynamic macromolecular network. Proteoglycans are major components of extracellular matrix playing key roles in its structural organization and cell signaling contributing to the control of numerous normal and pathological processes. As multifunctional molecules, proteoglycans participate in various cell functions during morphogenesis, wound healing, inflammation and tumorigenesis. Their interactions with matrix effectors, cell surface receptors and enzymes enable them with unique properties. In malignancy, extensive remodeling of tumor stroma is associated with marked alterations in proteoglycans' expression and structural variability. Proteoglycans exert diverse functions in tumor stroma in a cell-specific and context-specific manner and they mainly contribute to the formation of a permissive provisional matrix for tumor growth affecting tissue organization, cell-cell and cell-matrix interactions and tumor cell signaling. Proteoglycans also modulate cancer cell phenotype and properties, the development of drug resistance and tumor stroma angiogenesis. This review summarizes the proteoglycans remodeling and their novel biological roles in malignancies with particular emphasis to the underlying molecular mechanisms. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Sea level adaptation decisions under uncertainty

    DEFF Research Database (Denmark)

    Thorarinsdottir, T. L.; Guttorp, P.; Drews, M.

    2017-01-01

    Sea level rise has serious consequences for harbor infrastructure, storm drains and sewer systems, and many other issues. Adapting to sea level rise requires comparing different possible adaptation strategies, comparing the cost of different actions (including no action), and assessing where...... and at what point in time the chosen strategy should be implemented. All these decisions must be made under considerable uncertainty—in the amount of sea level rise, in the cost and prioritization of adaptation actions, and in the implications of no action. Here we develop two illustrative examples...

  11. Radiation damage at the molecular level: Nanodosimetry

    International Nuclear Information System (INIS)

    Blanco, F.; Munoz, A.; Lagares, J. I.; Nunez, L.; Garcia, G.

    2013-01-01

    One of the main practical use of the model is its use as a tool of nanodosimetry which basically consists in characterizing the effect of radiation on nano volumes (comparable to the DNA of volumes) in terms of link breaks and molecular dissociations. (Author)

  12. Molecular mechanisms underlying phosphate sensing, signaling, and adaptation in plants.

    Science.gov (United States)

    Zhang, Zhaoliang; Liao, Hong; Lucas, William J

    2014-03-01

    As an essential plant macronutrient, the low availability of phosphorus (P) in most soils imposes serious limitation on crop production. Plants have evolved complex responsive and adaptive mechanisms for acquisition, remobilization and recycling of phosphate (Pi) to maintain P homeostasis. Spatio-temporal molecular, physiological, and biochemical Pi deficiency responses developed by plants are the consequence of local and systemic sensing and signaling pathways. Pi deficiency is sensed locally by the root system where hormones serve as important signaling components in terms of developmental reprogramming, leading to changes in root system architecture. Root-to-shoot and shoot-to-root signals, delivered through the xylem and phloem, respectively, involving Pi itself, hormones, miRNAs, mRNAs, and sucrose, serve to coordinate Pi deficiency responses at the whole-plant level. A combination of chromatin remodeling, transcriptional and posttranslational events contribute to globally regulating a wide range of Pi deficiency responses. In this review, recent advances are evaluated in terms of progress toward developing a comprehensive understanding of the molecular events underlying control over P homeostasis. Application of this knowledge, in terms of developing crop plants having enhanced attributes for P use efficiency, is discussed from the perspective of agricultural sustainability in the face of diminishing global P supplies. © 2014 Institute of Botany, Chinese Academy of Sciences.

  13. Hybrid structures for molecular level sensing

    Science.gov (United States)

    Lemieux, Melburne Charles

    With substantial molecular mobility and segment dynamics relative to metals and ceramics, all polymeric materials, to some extent, are stimuli-responsive by exhibiting pronounced chemical and physical changes in the backbone, side chains, segments, or end groups induced by changes in the local environment. Thus, the push to incorporate polymeric materials as sensing/responsive nanoscale layers into next-generation miniaturized sensor applications is a natural progression. The significance and impact of this research is wide-ranging because it offers design considerations and presents results in perhaps two of the most critical broad areas of nanotechnology: ultrathin multifunctional polymer coatings and miniaturized sensors. In this work, direct evidence is given showing that polymer coatings comprised of deliberately selected molecular segments with very different chemistry can have switchable properties, and that the surface composition can be precisely controlled, and thus properties can be tuned: all in films on the order of 20 nm and less. Furthermore, active sensing layers in the form of plasma-polymerized polymers are successfully incorporated into actual silicon based microsensors resulting in a novel hybrid organic/inorganic materials platform for microfabricated MEMS sensors with record performance far beyond contemporary sensors in terms of detection sensitivity to various environments. The results produced in this research show thermal sensors with more than two orders of magnitude better sensitivity than what is attainable currently. In addition, a humidity response on the order of parts per trillion, which is four orders of magnitude more sensitive than current designs is achieved. Molecular interactions and forces for organic molecules are characterized at the picoscale to optimize polymeric nanoscale layer design that in turn optimize and lead to microscale hybrid sensors with unprecedented sensitivities.

  14. Developing State Level Approaches under the State Level Concept

    International Nuclear Information System (INIS)

    Budlong Sylvester, K.; Murphy, C.L.; Boyer, B.; Pilat, J.F.

    2015-01-01

    With the pursuit of the State-Level Concept (SLC), the IAEA has sought to further evolve the international safeguards system in a manner which maintains (or improves) the effectiveness of the system in an environment of expanding demands and limited resources. The IAEA must not remain static and should continuously examine its practices to ensure it can capture opportunities for cost reductions while adapting to, and staying ahead of, emerging proliferation challenges. Contemporary safeguards have been focused on assessing the nuclear programme of the State as a whole, rather than on the basis of individual facilities. Since the IAEA's integrated safeguards program, State-level Approaches (SLAs) have been developed that seek to optimally combine the measures provided for by the Additional Protocol with those of traditional safeguards. This process resulted in facility specific approaches that, while making use of a State's broader conclusion, were nonetheless prescriptive. Designing SLAs on a State-by-State basis would avoid the shortcomings of a one-size-fits-all system. It would also enable the effective use of the Agency's information analysis and State evaluation efforts by linking this analysis to safeguards planning efforts. Acquisition Path Analysis (APA), along with the State Evaluation process, can be used to prioritize paths in a State in terms of their attractiveness for proliferation. While taking advantage of all safeguards relevant information, and tailoring safeguards to individual characteristics of the State, paths of the highest priority in all States will necessarily meet the same standard of coverage. Similarly, lower priority paths will have lower performance targets, thereby promoting nondiscrimination. Such an approach would improve understanding of safeguards implementation under the SLC and the rational for safeguards resource allocation. The potential roles for APA and performance targets in SLA development will be reviewed

  15. Molecular investigations on grain filling rate under terminal heat ...

    African Journals Online (AJOL)

    Ezedom Theresa

    2013-07-10

    Jul 10, 2013 ... Grain yield under post anthesis high temperature stress is largely influenced by grain filling rate (GFR). To investigate molecular basis of this trait, a set of 111 recombinant inbred lines (RILs) derived from Raj. 4014, a heat sensitive genotype and WH 730, heat tolerant cultivar was phenotyped during 2009- ...

  16. Molecular investigations on grain filling rate under terminal heat ...

    African Journals Online (AJOL)

    Grain yield under post anthesis high temperature stress is largely influenced by grain filling rate (GFR). To investigate molecular basis of this trait, a set of 111 recombinant inbred lines (RILs) derived from Raj 4014, a heat sensitive genotype and WH 730, heat tolerant cultivar was phenotyped during 2009-2010 and ...

  17. Post-learning molecular reactivation underlies taste memory consolidation

    Directory of Open Access Journals (Sweden)

    Kioko eGuzman-Ramos

    2011-09-01

    Full Text Available It is considered that memory consolidation is a progressive process that requires post-trial stabilization of the information. In this regard, it has been speculated that waves of receptors activation, expression of immediate early genes and replenishment of receptor subunit pools occur to induce functional or morphological changes to maintain the information for longer periods. In this paper, we will review data related to neuronal changes in the post-acquisition stage of taste aversion learning that could be involved in further stabilization of the memory trace. In order to achieve such stabilization, evidence suggests that the functional integrity of the insular cortex (IC and the amygdala (AMY is required. Particularly the increase of extracellular levels of glutamate and activation of N-methyl-D-aspartate (NMDA receptors within the IC shows a main role in the consolidation process. Additionally the modulatory actions of the dopaminergic system in the IC appear to be involved in the mechanisms that lead to taste aversion memory consolidation through the activation of pathways related to enhancement of protein synthesis such as the Protein Kinase A pathway. In summary, we suggest that post-acquisition molecular and neuronal changes underlying memory consolidation are dependent on the interactions between the AMY and the IC.

  18. Effect of heavy metals and organic matter on root exudates (low molecular weight organic acids) of herbaceous species: An assessment in sand and soil conditions under different levels of contamination.

    Science.gov (United States)

    Montiel-Rozas, M M; Madejón, E; Madejón, P

    2016-09-01

    Bioavailability of heavy metals can be modified by different root exudates. Among them, low molecular weight organic acids (LMWOAs) play an important role in this process. Three plant species (Poa annua, Medicago polymorpha and Malva sylvestris), potentially used for phytoremediation, have been assessed for both metal uptake and LMWOAs excretion in contaminated environments with different concentrations of Cd, Cu and Zn. The experiments have been carried out in washed sand and in three contaminated soils where two organic amendments were added (biosolid compost and alperujo compost). The most abundant LMWOAs excreted by all studied plants were oxalic and malic acids, although citric and fumaric acids were also detected. The general tendency was that plants responded to an increase of heavy metal stress releasing higher amounts of LMWOAs. This is an efficient exclusion mechanism reducing the metal uptake and allowing the plant growth at high levels of contamination. In the experiment using wash sand as substrate, the organic acids composition and quantity depended mainly on plant species and metal contamination. M. polymorpha was the species that released the highest concentrations of LMWOAs, both in sand and in soils with no amendment addition, whereas a decrease of these acids was observed with the addition of amendments. Our results established a clear effect of organic matter on the composition and total amount of LMWOAs released. The increase of organic matter and nutrients, through amendments, improved the soil quality reducing phytotoxicity. As a result, organic acids exudates decreased and were solely composed of oxalic acid (except for M. polymorpha). The release of LMWOAs has proved to be an important mechanism against heavy metal stress, unique to each species and modifiable by means of organic amendment addition. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Deciphering Molecular Mechanism Underlying Hypolipidemic Activity of Echinocystic Acid

    Directory of Open Access Journals (Sweden)

    Li Han

    2014-01-01

    Full Text Available Our previous study showed that a triterpene mixture, consisting of echinocystic acid (EA and oleanolic acid (OA at a ratio of 4 : 1, dose-dependently ameliorated the hyperlipidemia and atherosclerosis in rabbits fed with high fat/high cholesterol diets. This study was aimed at exploring the mechanisms underlying antihyperlipidemic effect of EA. Molecular docking simulation of EA was performed using Molegro Virtual Docker (version: 4.3.0 to investigate the potential targets related to lipid metabolism. Based on the molecular docking information, isotope labeling method or spectrophotometry was applied to examine the effect of EA on the activity of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA reductase, acyl-CoA:cholesterol acyltransferase (ACAT, and diacylglycerol acyltransferase (DGAT in rat liver microsomes. Our results revealed a strong affinity of EA towards ACAT and DGAT in molecular docking analysis, while low binding affinity existed between EA and HMG-CoA reductase as well as between EA and cholesteryl ester transfer protein. Consistent with the results of molecular docking, in vitro enzyme activity assays showed that EA inhibited ACAT and DGAT, with IC50 values of 103 and 139 μM, respectively, and exhibited no significant effect on HMG-CoA reductase activity. The present findings suggest that EA may exert hypolipidemic effect by inhibiting the activity of ACAT and DGAT.

  20. Practical γ-Ray Level for Low Molecular Weight Chitosan

    International Nuclear Information System (INIS)

    Yoksan, Rangrong; Chirachanchai, Suwabun; Biramontri, Siriratana

    2003-06-01

    The present work proposes a practical level of γ-Ray to lower the molecular weigh of chitosan irradiated in solid state and water. The molecular weight reduction is up to 80% at γ-ray amount of 50 kGy. The same level of reduction can be achieved by only 20 kGy in the presence of initiator (K 2 S 2 O 8 or H 2 O 2 ). The structure is significantly changed in the case of chitosan-acetic acid solution or chitosan dispersed in water with 2% aq. K 2 S 2 O 8 solution

  1. Molecular-level insights into aging processes of skin elastin

    DEFF Research Database (Denmark)

    Mora Huertas, Angela C; Schmelzer, Christian E H; Hoehenwarter, Wolfgang

    2016-01-01

    Skin aging is characterized by different features including wrinkling, atrophy of the dermis and loss of elasticity associated with damage to the extracellular matrix protein elastin. The aim of this study was to investigate the aging process of skin elastin at the molecular level by evaluating t...

  2. A systematic molecular circuit design method for gene networks under biochemical time delays and molecular noises

    Directory of Open Access Journals (Sweden)

    Chang Yu-Te

    2008-11-01

    Full Text Available Abstract Background Gene networks in nanoscale are of nonlinear stochastic process. Time delays are common and substantial in these biochemical processes due to gene transcription, translation, posttranslation protein modification and diffusion. Molecular noises in gene networks come from intrinsic fluctuations, transmitted noise from upstream genes, and the global noise affecting all genes. Knowledge of molecular noise filtering and biochemical process delay compensation in gene networks is crucial to understand the signal processing in gene networks and the design of noise-tolerant and delay-robust gene circuits for synthetic biology. Results A nonlinear stochastic dynamic model with multiple time delays is proposed for describing a gene network under process delays, intrinsic molecular fluctuations, and extrinsic molecular noises. Then, the stochastic biochemical processing scheme of gene regulatory networks for attenuating these molecular noises and compensating process delays is investigated from the nonlinear signal processing perspective. In order to improve the robust stability for delay toleration and noise filtering, a robust gene circuit for nonlinear stochastic time-delay gene networks is engineered based on the nonlinear robust H∞ stochastic filtering scheme. Further, in order to avoid solving these complicated noise-tolerant and delay-robust design problems, based on Takagi-Sugeno (T-S fuzzy time-delay model and linear matrix inequalities (LMIs technique, a systematic gene circuit design method is proposed to simplify the design procedure. Conclusion The proposed gene circuit design method has much potential for application to systems biology, synthetic biology and drug design when a gene regulatory network has to be designed for improving its robust stability and filtering ability of disease-perturbed gene network or when a synthetic gene network needs to perform robustly under process delays and molecular noises.

  3. Molecular Bases Underlying the Hepatoprotective Effects of Coffee

    Directory of Open Access Journals (Sweden)

    Federico Salomone

    2017-01-01

    Full Text Available Coffee is the most consumed beverage worldwide. Epidemiological studies with prospective cohorts showed that coffee intake is associated with reduced cardiovascular and all-cause mortality independently of caffeine content. Cohort and case-control studies reported an inverse association between coffee consumption and the degree of liver fibrosis as well as the development of liver cancer. Furthermore, the beneficial effects of coffee have been recently confirmed by large meta-analyses. In the last two decades, various in vitro and in vivo studies evaluated the molecular determinants for the hepatoprotective effects of coffee. In the present article, we aimed to critically review experimental evidence regarding the active components and the molecular bases underlying the beneficial role of coffee against chronic liver diseases. Almost all studies highlighted the beneficial effects of this beverage against liver fibrosis with the most solid results indicating a pivot role for both caffeine and chlorogenic acids. In particular, in experimental models of fibrosis, caffeine was shown to inhibit hepatic stellate cell activation by blocking adenosine receptors, and emerging evidence indicated that caffeine may also favorably impact angiogenesis and hepatic hemodynamics. On the other side, chlorogenic acids, potent phenolic antioxidants, suppress liver fibrogenesis and carcinogenesis by reducing oxidative stress and counteract steatogenesis through the modulation of glucose and lipid homeostasis in the liver. Overall, these molecular insights may have translational significance and suggest that coffee components need clinical evaluation.

  4. Molecular mechanisms underlying the development of hepatocellular carcinoma.

    Science.gov (United States)

    Bergsland, E K

    2001-10-01

    Hepatocellular carcinoma (HCC) is a disease that is extremely difficult to manage and is markedly increasing in incidence. Malignant transformation generally occurs in the setting of liver dysfunction related to a number of different diseases, including viral hepatitis, alcoholic liver disease, and aflatoxin exposure. Short of surgical or ablative approaches, no standard therapy exists for HCC and the prognosis is poor. Perhaps our best hope is that further elucidation of the specific molecular features underlying the disease will translate into innovative, and potentially disease-specific strategies to manage this difficult cancer. Exposure to aflatoxin is associated with a specific mutation in the tumor-suppressor gene p53. The exact molecular events underlying hepatocarcinogenesis in the setting of viral infection have yet to be elucidated, although there is evidence to suggest that virus-encoded proteins contribute to malignant transformation. Both hepatitis B X antigen and hepatitis C core protein appear to interact with a variety of cellular proteins leading to alterations in signal transduction and transcriptional activity. These events presumably cooperate to facilitate malignant progression by promoting extended hepatocyte survival, evasion of the immune response, and acquisition of mutations through genomic instability. Copyright 2001 by W.B. Saunders Company.

  5. PREFACE: International Symposium on Molecular Conductors: Novel Functions of Molecular Conductors under Extreme Conditions (ISMC 2008)

    Science.gov (United States)

    Takahashi, Toshihiro; Suzumura, Yoshikazu

    2008-02-01

    The International Symposium on Molecular Conductors 2008 (ISMC2008) was held as the second international symposium of the project entitled `Novel Functions of Molecular Conductors under Extreme Conditions', which was supported by the Grant-in-aid for Scientific Research on Priority Areas from the Ministry of Education, Culture, Sports, Science and Technology in Japan. The project lasted from September 2003 to March 2008, and was completed by this symposium held at Okazaki Conference Center, Institute for Molecular Science, Okazaki, Japan (23-25 July 2008), which about 100 scientists attended. During the symposium, five project teams gave summary talks and exciting talks were given on the topics developed recently not only by the members of the project but also by other scientists including invited speakers from abroad, who are doing active research on molecular conductors. It is expected that papers presented in the symposium will give valuable hints for the next step in the research of this field. Therefore the organizers of this symposium decided to publish this proceedings in order to demonstrate these activities, not only for the local community of the project, but also for the broad society of international scientists who are interested in molecular conductors. The editors, who are also the organizers of this symposium, believe that this proceedings provides a significant and relevant contribution to the field of molecular conductors since it is the first time we have published such a proceedings as an electronic journal. We note that all papers published in this volume of Journal of Physics: Conference Series have been peer reviewed by expert referees. Editors made every effort to satisfy the criterion of a proceedings journal published by IOP Publishing. Toshihiro Takahashi and Yoshikazu Suzumura Editors: Toshihiro Takahashi (Gakushuin University) (Chairman) Kazushi Kanoda (University of Tokyo) Seiichi Kagoshima (University of Tokyo) Takehiko Mori (Tokyo

  6. Immobilized enzymes: understanding enzyme - surface interactions at the molecular level.

    Science.gov (United States)

    Hoarau, Marie; Badieyan, Somayesadat; Marsh, E Neil G

    2017-11-22

    Enzymes immobilized on solid supports have important and industrial and medical applications. However, their uses are limited by the significant reductions in activity and stability that often accompany the immobilization process. Here we review recent advances in our understanding of the molecular level interactions between proteins and supporting surfaces that contribute to changes in stability and activity. This understanding has been facilitated by the application of various surface-sensitive spectroscopic techniques that allow the structure and orientation of enzymes at the solid/liquid interface to be probed, often with monolayer sensitivity. An appreciation of the molecular interactions between enzyme and surface support has allowed the surface chemistry and method of enzyme attachement to be fine-tuned such that activity and stability can be greatly enhanced. These advances suggest that a much wider variety of enzymes may eventually be amenable to immobilization as green catalysts.

  7. Soy protein isolate molecular level contributions to bulk adhesive properties

    Science.gov (United States)

    Shera, Jeanne Norton

    Increasing environmental awareness and the recognized health hazards of formaldehyde-based resins has prompted a strong demand for environmentally-responsible adhesives for wood composites. Soy protein-based adhesives have been shown to be commercially viable with 90-day shelf stability and composite physical properties comparable to those of commercial formaldehyde-based particleboards. The main research focus is to isolate and characterize the molecular level features in soy protein isolate responsible for providing mechanical properties, storage stability, and water resistance during adhesive formulation, processing, and wood composite fabrication. Commercial composite board will be reviewed to enhance our understanding of the individual components and processes required for particleboard production. The levels of protein structure will be defined and an overview of current bio-based technology will be presented. In the process, the logic for utilizing soy protein as a sole binder in the adhesive will be reinforced. Variables such as adhesive components, pH, divalent ions, blend aging, protein molecular weight, formulation solids content, and soy protein functionalization will relate the bulk properties of soy protein adhesives to the molecular configuration of the soybean protein. This work has demonstrated that when intermolecular beta-sheet interactions and protein long-range order is disrupted, viscosity and mechanical properties decrease. Storage stability can be maintained through the stabilization of intermolecular beta-sheet interactions. When molecular weight is reduced through enzymatic digestion, long-range order is disrupted and viscosity and mechanical properties decrease accordingly. Processibility and physical properties must be balanced to increase solids while maintaining low viscosity, desirable mechanical properties, and adequate storage stability. The structure of the soybean protein must be related to the particleboard bulk mechanical

  8. The quest for molecular regulation underlying unisexual flower development

    Directory of Open Access Journals (Sweden)

    Rómulo eSobral

    2016-02-01

    Full Text Available The understanding of the molecular mechanisms responsible for the making of a unisexual flower has been a long-standing quest in plant biology. Plants with male and female flowers can be divided mainly into two categories: dioecious and monoecious, and both sexual systems co-exist in nature in ca of 10% of the angiosperms. The establishment of male and female traits has been extensively described in a hermaphroditic flower and requires the interplay of networks, directly and indirectly related to the floral organ identity genes including hormonal regulators, transcription factors, microRNAs, and chromatin-modifying proteins. Recent transcriptomic studies have been uncovering the molecular processes underlying the establishment of unisexual flowers and there are many parallelisms between monoecious, dioecious and hermaphroditic individuals. Here, we review the paper entitled Comparative transcriptomic analysis of male and female flowers of monoecious Quercus suber published in 2014 in the Frontiers of Plant Science (volume 5 | Article 599 and discussed it in the context of recent studies with other dioecious and monoecious plants that utilized high-throughput platforms to obtain transcriptomic profiles of male and female unisexual flowers. In some unisexual flowers, the developmental programs that control organ initiation fail and male or female organs do not form, whereas in other species, organ initiation and development occur but they abort or arrest during different species-specific stages of differentiation. Therefore, a direct comparison of the pathways responsible for the establishment of unisexual flowers in different species are likely to reveal conserved modules of gene regulatory hubs involved in stamen or carpel development, as well as differences that reflect the different stages of development in which male and/or female organ arrest or loss-of-function occurs.

  9. Molecular level in silico studies for oncology. Direct models review

    Science.gov (United States)

    Psakhie, S. G.; Tsukanov, A. A.

    2017-09-01

    The combination of therapy and diagnostics in one process "theranostics" is a trend in a modern medicine, especially in oncology. Such an approach requires development and usage of multifunctional hybrid nanoparticles with a hierarchical structure. Numerical methods and mathematical models play a significant role in the design of the hierarchical nanoparticles and allow looking inside the nanoscale mechanisms of agent-cell interactions. The current position of in silico approach in biomedicine and oncology is discussed. The review of the molecular level in silico studies in oncology, which are using the direct models, is presented.

  10. Neuroprotective strategies and the underlying molecular basis of cerebrovascular stroke.

    Science.gov (United States)

    Karsy, Michael; Brock, Andrea; Guan, Jian; Taussky, Phillip; Kalani, M Yashar S; Park, Min S

    2017-04-01

    Stroke is a leading cause of disability in the US. Although there has been significant progress in the area of medical and surgical thrombolytic technologies, neuroprotective agents to prevent secondary cerebral injury and to minimize disability remain limited. Only limited success has been reported in preclinical and clinical trials evaluating a variety of compounds. In this review, the authors discuss the most up-to-date information regarding the underlying molecular biology of stroke as well as strategies that aim to mitigate this complex signaling cascade. Results of historical research trials involving N-methyl-d-aspartate and α-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor antagonists, clomethiazole, antioxidants, citicoline, nitric oxide, and immune regulators have laid the groundwork for current progress. In addition, more recent studies involving therapeutic hypothermia, magnesium, albumin, glyburide, uric acid, and a variety of other treatments have provided more options. The use of neuroprotective agents in combination or with existing thrombolytic treatments may be one of many exciting areas of further development. Although past trials of neuroprotective agents in ischemic stroke have been limited, significant insights into mechanisms of stroke, animal models, and trial design have incrementally improved approaches for future therapies.

  11. Molecular Targets Underlying the Anticancer Effects of Quercetin: An Update.

    Science.gov (United States)

    Khan, Fazlullah; Niaz, Kamal; Maqbool, Faheem; Ismail Hassan, Fatima; Abdollahi, Mohammad; Nagulapalli Venkata, Kalyan C; Nabavi, Seyed Mohammad; Bishayee, Anupam

    2016-08-29

    Quercetin, a medicinally important member of the flavonoid family, is one of the most prominent dietary antioxidants. It is present in a variety of foods-including fruits, vegetables, tea, wine, as well as other dietary supplements-and is responsible for various health benefits. Numerous pharmacological effects of quercetin include protection against diseases, such as osteoporosis, certain forms of malignant tumors, and pulmonary and cardiovascular disorders. Quercetin has the special ability of scavenging highly reactive species, such as hydrogen peroxide, superoxide anion, and hydroxyl radicals. These oxygen radicals are called reactive oxygen species, which can cause oxidative damage to cellular components, such as proteins, lipids, and deoxyribonucleic acid. Various oxygen radicals play important roles in pathophysiological and degenerative processes, such as aging. Subsequently, several studies have been performed to evaluate possible advantageous health effects of quercetin and to collect scientific evidence for these beneficial health claims. These studies also gather data in order to evaluate the exact mechanism(s) of action and toxicological effects of quercetin. The purpose of this review is to present and critically analyze molecular pathways underlying the anticancer effects of quercetin. Current limitations and future directions of research on this bioactive dietary polyphenol are also critically discussed.

  12. Synergistic effect of fluorination on molecular energy level modulation in highly efficient photovoltaic polymers.

    Science.gov (United States)

    Zhang, Maojie; Guo, Xia; Zhang, Shaoqing; Hou, Jianhui

    2014-02-01

    The synergistic effect of fluorination on molecular energy level modulation is realized by introducing fluorine atoms onto both the donor and the acceptor moieties in a D-A polymer, and as a result, the polymer solar cell device based on the trifluorinated polymer, PBT-3F, shows a high efficiency of 8.6%, under illumination of AM 1.5G, 100 mW cm(-) (2) . © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Molecular Mechanics: The Method and Its Underlying Philosophy.

    Science.gov (United States)

    Boyd, Donald B.; Lipkowitz, Kenny B.

    1982-01-01

    Molecular mechanics is a nonquantum mechanical method for solving problems concerning molecular geometries and energy. Methodology based on: the principle of combining potential energy functions of all structural features of a particular molecule into a total force field; derivation of basic equations; and use of available computer programs is…

  14. Unraveling the Molecular Mechanisms Underlying the Nasopharyngeal Bacterial Community Structure

    Directory of Open Access Journals (Sweden)

    Wouter A. A. de Steenhuijsen Piters

    2016-03-01

    Full Text Available The upper respiratory tract is colonized by a diverse array of commensal bacteria that harbor potential pathogens, such as Streptococcus pneumoniae. As long as the local microbial ecosystem—also called “microbiome”—is in balance, these potentially pathogenic bacterial residents cause no harm to the host. However, similar to macrobiological ecosystems, when the bacterial community structure gets perturbed, potential pathogens can overtake the niche and cause mild to severe infections. Recent studies using next-generation sequencing show that S. pneumoniae, as well as other potential pathogens, might be kept at bay by certain commensal bacteria, including Corynebacterium and Dolosigranulum spp. Bomar and colleagues are the first to explore a specific biological mechanism contributing to the antagonistic interaction between Corynebacterium accolens and S. pneumoniae in vitro [L. Bomar, S. D. Brugger, B. H. Yost, S. S. Davies, K. P. Lemon, mBio 7(1:e01725-15, 2016, doi:10.1128/mBio.01725-15]. The authors comprehensively show that C. accolens is capable of hydrolyzing host triacylglycerols into free fatty acids, which display antipneumococcal properties, suggesting that these bacteria might contribute to the containment of pneumococcus. This work exemplifies how molecular epidemiological findings can lay the foundation for mechanistic studies to elucidate the host-microbe and microbial interspecies interactions underlying the bacterial community structure. Next, translation of these results to an in vivo setting seems necessary to unveil the magnitude and importance of the observed effect in its natural, polymicrobial setting.

  15. Circadian timekeeping is disturbed in rheumatoid arthritis at molecular level.

    Directory of Open Access Journals (Sweden)

    Vesa-Petteri Kouri

    Full Text Available INTRODUCTION: Patients with rheumatoid arthritis (RA have disturbances in the hypothalamic-pituitary-adrenal (HPA axis. These are reflected in altered circadian rhythm of circulating serum cortisol, melatonin and IL-6 levels and in chronic fatigue. We hypothesized that the molecular machinery responsible for the circadian timekeeping is perturbed in RA. The aim of this study was to investigate the expression of circadian clock in RA. METHODS: Gene expression of thirteen clock genes was analyzed in the synovial membrane of RA and control osteoarthritis (OA patients. BMAL1 protein was detected using immunohistochemistry. Cell autonomous clock oscillation was started in RA and OA synovial fibroblasts using serum shock. The effect of pro-inflammatory stimulus on clock gene expression in synovial fibroblasts was studied using IL-6 and TNF-α. RESULTS: Gene expression analysis disclosed disconcerted circadian timekeeping and immunohistochemistry revealed strong cytoplasmic localization of BMAL1 in RA patients. Perturbed circadian timekeeping is at least in part inflammation independent and cell autonomous, because RA synovial fibroblasts display altered circadian expression of several clock components, and perturbed circadian production of IL-6 and IL-1β after clock resetting. However, inflammatory stimulus disturbs the rhythm in cultured fibroblasts. Throughout the experiments ARNTL2 and NPAS2 appeared to be the most affected clock genes in human immune-inflammatory conditions. CONCLUSION: We conclude that the molecular machinery controlling the circadian rhythm is disturbed in RA patients.

  16. Molecular-Level Simulations of the Turbulent Taylor-Green Flow

    Science.gov (United States)

    Gallis, M. A.; Bitter, N. P.; Koehler, T. P.; Plimpton, S. J.; Torczynski, J. R.; Papadakis, G.

    2017-11-01

    The Direct Simulation Monte Carlo (DSMC) method, a statistical, molecular-level technique that provides accurate solutions to the Boltzmann equation, is applied to the turbulent Taylor-Green vortex flow. The goal of this work is to investigate whether DSMC can accurately simulate energy decay in a turbulent flow. If so, then simulating turbulent flows at the molecular level can provide new insights because the energy decay can be examined in detail from molecular to macroscopic length scales, thereby directly linking molecular relaxation processes to macroscopic transport processes. The DSMC simulations are performed on half a million cores of Sequoia, the 17 Pflop platform at Lawrence Livermore National Laboratory, and the kinetic-energy dissipation rate and the energy spectrum are computed directly from the molecular velocities. The DSMC simulations are found to reproduce the Kolmogorov -5/3 law and to agree with corresponding Navier-Stokes simulations obtained using a spectral method. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525.

  17. Molecular pathways associated with blood pressure and hexadecanedioate levels.

    Directory of Open Access Journals (Sweden)

    Cristina Menni

    Full Text Available The dicarboxylic acid hexadecanedioate is associated with increased blood pressure (BP and mortality in humans and feeding it to rats raises BP. Here we aim to characterise the molecular pathways that influence levels of hexadecanedioate linked to BP regulation, using genetic and transcriptomic studies. The top associations for hexadecanedioate in a genome-wide association scan (GWAS conducted on 6447 individuals from the TwinsUK and KORA cohorts were tested for association with BP and hypertension in the International Consortium for BP and in a GWAS of BP extremes. Transcriptomic analyses correlating hexadecanedioate with gene expression levels in adipose tissue in 740 TwinsUK participants were further performed. GWAS showed 242 SNPs mapping to two independent loci achieving genome-wide significance. In rs414056 in the SCLO1B1 gene (Beta(SE = -0.088(0.006P = 1.65 x 10-51, P < 1 x 10-51, the allele previously associated with increased risk of statin associated myopathy is associated with higher hexadecanedioate levels. However this SNP did not show association with BP or hypertension. The top SNP in the second locus rs6663731 mapped to the intronic region of CYP4Z2P on chromosome 1 (0.045(0.007, P = 5.49x10-11. Hexadecanedioate levels also correlate with adipose tissue gene-expression of the 3 out of 4 CYP4 probes (P<0.05 and of alcohol dehydrogenase probes (Beta(SE = 0.12(0.02; P = 6.04x10-11. High circulating levels of hexadecanedioate determine a significant effect of alcohol intake on BP (SBP: 1.12(0.34, P = 0.001; DBP: 0.70(0.22, P = 0.002, while no effect is seen in the lower hexadecanedioate level group. In conclusion, levels in fat of ADH1A, ADH1B and CYP4 encoding enzymes in the omega oxidation pathway, are correlated with hexadecanedioate levels. Hexadecanedioate appears to regulate the effect of alcohol on BP.

  18. Orbital Energy Levels in Molecular Hydrogen. A Simple Approach.

    Science.gov (United States)

    Willis, Christopher J.

    1988-01-01

    Described are the energetics involved in the formation of molecular hydrogen using concepts that should be familiar to students beginning the study of molecular orbital theory. Emphasized are experimental data on ionization energies. Included are two-electron atomic and molecular systems. (CW)

  19. Modelling Molecular Mechanisms: A Framework of Scientific Reasoning to Construct Molecular-Level Explanations for Cellular Behaviour

    Science.gov (United States)

    van Mil, Marc H. W.; Boerwinkel, Dirk Jan; Waarlo, Arend Jan

    2013-01-01

    Although molecular-level details are part of the upper-secondary biology curriculum in most countries, many studies report that students fail to connect molecular knowledge to phenomena at the level of cells, organs and organisms. Recent studies suggest that students lack a framework to reason about complex systems to make this connection. In this…

  20. Modelling molecular mechanisms: a framework of scientific reasoning to construct molecular-level explanations for cellular behaviour

    NARCIS (Netherlands)

    van Mil, M.H.W.; Boerwinkel, D.J.; Waarlo, A.J.

    2013-01-01

    Although molecular-level details are part of the upper-secondary biology curriculum in most countries, many studies report that students fail to connect molecular knowledge to phenomena at the level of cells, organs and organisms. Recent studies suggest that students lack a framework to reason about

  1. Global SUMOylation is a Molecular Mechanism Underlying Hypothermia-induced Ischemic Tolerance

    Directory of Open Access Journals (Sweden)

    Yang-ja eLee

    2014-12-01

    Full Text Available The molecular mechanisms underlying hypothermic neuroprotection have yet to be fully elucidated. Herein we demonstrate that global SUMOylation, a form of post-translational modification with the Small Ubiquitin-like MOdifer, participates in the multimodal molecular induction of hypothermia-induced ischemic tolerance. Mild (32°C to moderate (28°C hypothermic treatment(s during OGD (oxygen-glucose-deprivation or ROG (restoration of oxygen/glucose increased global SUMO-conjugation levels and protected cells (both SHSY5Y and E18 rat cortical neurons from OGD and ROG-induced cell death. Hypothermic exposure either before or after permanent middle cerebral artery occlusion (pMCAO surgery in wild type mice increased global SUMO-conjugation levels in the brain and in so doing protected these animals from pMCAO-induced ischemic damage. Of note, hypothermic exposure did not provide an additional increase in protection from pMCAO-induced ischemic brain damage in Ubc9 transgenic mice, which overexpress the sole E2 SUMO conjugating enzyme and thereby display elevated basal levels of global SUMOylation under normothermic conditions. Such evidence suggests that increases in global SUMOylation are critical and may account for a substantial part of the observed increase in cellular tolerance to brain ischemia caused via hypothermia.

  2. Robustness of Two-Level Testing Procedures under Distortions of First Level Statistics

    OpenAIRE

    Kostevich, A. L.; Nikitina, I. S.

    2007-01-01

    We investigate robustness of some two-level testing procedures under distortions induced by using an asymptotic distribution of first level statistics instead of an exact one. We demonstrate that ignoring the distortions results in unreliable conclusions and we propose robustness conditions for the two-level procedures.

  3. Molecular mechanisms underlying thermal adaptation of xeric animals

    Indian Academy of Sciences (India)

    2007-03-15

    Mar 15, 2007 ... Author Affiliations. M B Evgen'Ev1 2 D G Garbuz1 V Y Shilova1 O G Zatsepina1. Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov Street 32, Moscow 199991, Russia; Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142292, Russia ...

  4. Survival under stress: molecular mechanisms of metabolic rate ...

    African Journals Online (AJOL)

    Studies in my laboratory are analysing the molecular mechanisms and regulatory events that underlie transitions to and from hypometabolic states In systems including anoxia-tolerant turtles and molluscs, estivating snails and toads, hibernating small mammals, and freeze tolerant frogs and insects. Our newest research ...

  5. Formation of neutrophil extracellular traps under low oxygen level

    Directory of Open Access Journals (Sweden)

    Katja Branitzki-Heinemann

    2016-11-01

    Full Text Available Since their discovery, neutrophil extracellular traps (NETs have been characterized as a fundamental host innate immune defense mechanism. Conversely, excessive NET release may have a variety of detrimental consequences for the host. A fine balance between NET formation and elimination is necessary to sustain a protective effect during an infectious challenge. Our own recently published data revealed that stabilization of hypoxia inducible factor 1α (HIF-1α by the iron chelating HIF-1α-agonist desferoxamine or AKB-4924 enhanced the release of phagocyte extracellular traps. Since HIF-1α is a global regulator of the cellular response to low oxygen, we hypothesized that NET formation may be similarly increased under low oxygen conditions. Hypoxia occurs in tissues during infection or inflammation, mostly due to overconsumption of oxygen by pathogens and recruited immune cells. Therefore, experiments were performed to characterize the formation of NETs under hypoxic oxygen conditions compared to normoxia. Human blood-derived neutrophils were isolated and incubated under normoxic (21% oxygen level and compared to hypoxic (1% conditions. Dissolved oxygen levels were monitored in the primary cell culture using a Fibox4-PSt3 measurement system. The formation of NETs was quantified by fluorescence microscopy in response to the known NET-inducer phorbol 12-myristate 13-acetate (PMA or S. aureus wildtype and a nuclease-deficient mutant. In contrast to our hypothesis, spontaneous NET formation of neutrophils incubated under hypoxia was distinctly reduced compared to control neutrophils incubated under normoxia. Furthermore, neutrophils incubated under hypoxia showed significantly reduced formation of NETs in response to PMA. Gene expression analysis revealed that mRNA level of hif-1α as well as hif-1α target genes was not altered. However, in good correlation to the decreased NET formation under hypoxia, the cholesterol content of the neutrophils was

  6. Actinides and environmental interfaces: striving for molecular-level understanding

    International Nuclear Information System (INIS)

    Heino Nitsche

    2005-01-01

    Actinides can undergo a variety of complex chemical reactions in the environment. In addition to the formation of solid precipitates, colloids and dissolved solution species common to aqueous systems, actinide ions can interact with the surrounding geo and biomedia to change oxidation states or sorb on surfaces and colloids. The rate of migration is determined by aqueous solubility, and interactions with solid surfaces such as minerals, soils, natural organic matter, and soil microorganisms Sorption of aqueous actinide species on biological and geological matrices can be quantitatively described by a surface complexation or site-binding model. The disadvantage of this model is the difficulty in the experimental determination of the model parameters and surface reaction constants. Usually, a set of surface reactions and species are proposed based on knowledge of the solution speciation of the solute, and the reaction constants are usually derived by fitting computer-calculated absorption curves to experimental data. Because this process typically involves a large number of potentially adjustable parameters, it is likely to lead to non-unique parameter fitting and does not always result in a consistent set of parameters for the same systems. A fundamental molecular-level understanding of sorption processes of actinides on environmental surfaces is required to better understand and predict their transport behavior in nature. Several different surface spectroscopic techniques have been applied to the characterization of the adsorbed species and surface reactions and a direct determination of the sorbed species and surface reactions has become possible. The non-linear optical techniques of second harmonic and sum frequency generation (SHG and SFG) are ideally suited to study surfaces and interfaces of mineral oxides, biosurfactants and biopolymers, organic adlayers adsorbed on solid/mineral surfaces and soil organic matter, including humic and fulvic acids. Resonant

  7. Advances Towards Synthetic Machines at the Molecular and Nanoscale Level

    Directory of Open Access Journals (Sweden)

    Kristina Konstas

    2010-06-01

    Full Text Available The fabrication of increasingly smaller machines to the nanometer scale can be achieved by either a “top-down” or “bottom-up” approach. While the former is reaching its limits of resolution, the latter is showing promise for the assembly of molecular components, in a comparable approach to natural systems, to produce functioning ensembles in a controlled and predetermined manner. In this review we focus on recent progress in molecular systems that act as molecular machine prototypes such as switches, motors, vehicles and logic operators.

  8. Molecular-level insights into aging processes of skin elastin.

    Science.gov (United States)

    Mora Huertas, Angela C; Schmelzer, Christian E H; Hoehenwarter, Wolfgang; Heyroth, Frank; Heinz, Andrea

    2016-01-01

    Skin aging is characterized by different features including wrinkling, atrophy of the dermis and loss of elasticity associated with damage to the extracellular matrix protein elastin. The aim of this study was to investigate the aging process of skin elastin at the molecular level by evaluating the influence of intrinsic (chronological aging) and extrinsic factors (sun exposure) on the morphology and susceptibility of elastin towards enzymatic degradation. Elastin was isolated from biopsies derived from sun-protected or sun-exposed skin of differently aged individuals. The morphology of the elastin fibers was characterized by scanning electron microscopy. Mass spectrometric analysis and label-free quantification allowed identifying differences in the cleavage patterns of the elastin samples after enzymatic digestion. Principal component analysis and hierarchical cluster analysis were used to visualize differences between the samples and to determine the contribution of extrinsic and intrinsic aging to the proteolytic susceptibility of elastin. Moreover, the release of potentially bioactive peptides was studied. Skin aging is associated with the decomposition of elastin fibers, which is more pronounced in sun-exposed tissue. Marker peptides were identified, which showed an age-related increase or decrease in their abundances and provide insights into the progression of the aging process of elastin fibers. Strong age-related cleavage occurs in hydrophobic tropoelastin domains 18, 20, 24 and 26. Photoaging makes the N-terminal and central parts of the tropoelastin molecules more susceptible towards enzymatic cleavage and, hence, accelerates the age-related degradation of elastin. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  9. Multi-level opinion dynamics under bounded confidence.

    Science.gov (United States)

    Kou, Gang; Zhao, Yiyi; Peng, Yi; Shi, Yong

    2012-01-01

    Opinion dynamics focuses on the opinion evolution in a social community. Recently, some models of continuous opinion dynamics under bounded confidence were proposed by Deffuant and Krause, et al. In the literature, agents were generally assumed to have a homogeneous confidence level. This paper proposes an extended model for a group of agents with heterogeneous confidence levels. First, a social differentiation theory is introduced and a social group is divided into opinion subgroups with distinct confidence levels. Second, a multi-level heterogeneous opinion formation model is formulated under the framework of bounded confidence. Finally, computer simulations are conducted to study the collective opinion evolution, focusing on three key factors: the fractions of heterogeneous agents, the initial opinions, and the group size. The simulation results demonstrate that the number of final opinions depends on the fraction of close-minded agents when the group size and the initial opinions are fixed; the final opinions converge more easily when the initial opinions are closer; and the number of final opinions can be approximately modeled by a linear increasing function of the group size and the increasing rate is the fraction of close-minded agents.

  10. Mechanisms of molecular electronic rectification through electronic levels with strong vibrational coupling

    DEFF Research Database (Denmark)

    Kuznetsov, A.M.; Ulstrup, Jens

    2002-01-01

    We present a new view and an analytical formalism of electron flow through a donor-acceptor molecule inserted between a pair of metal electrodes. The donor and acceptor levels are strongly coupled to an environmental nuclear continuum. The formalism applies to molecular donor-acceptor systems both...... in vacuum or air, and in aqueous solution under electrochemical potential control. Multifarious patterns of rectified electron flow from the negatively to the positively biased electrode arise. The electronic interaction between the donor and acceptor fragments, mutually and with the electrodes, can be weak...

  11. Phase behaviour of macromolecular liquid crystalline materials. Computational studies at the molecular level

    International Nuclear Information System (INIS)

    Stimson, Lorna M.

    2003-01-01

    Molecular simulations provide an increasingly useful insight into the static and dynamic characteristics of materials. In this thesis molecular simulations of macro-molecular liquid crystalline materials are reported. The first liquid crystalline material that has been investigated is a side chain liquid crystal polymer (SCLCP). In this study semi-atomistic molecular dynamics simulations have been conducted at a range of temperatures and an aligning potential has been applied to mimic the effect of a magnetic field. In cooling the SCLCP from an isotropic melt, microphase separation was observed yielding a domain structure. The application of a magnetic field to this structure aligns the domains producing a stable smectic mesophase. This is the first study in which mesophases have been observed using an off-lattice model of a SCLCP. The second material that has been investigated is a dendrimer with terminal mesogenic functionalization. Here, a multi-scale approach has been taken with Monte Carlo studies of a single dendrimer molecule in the gas phase at the atomistic level, semi-atomistic molecular dynamics of a single molecule in liquid crystalline solvents and a coarse-grained molecular dynamics study of the dendrimer in the bulk. The coarse-grained model has been developed and parameterized using the results of the atomistic and semi-atomistic work. The single molecule studies showed that the liquid crystalline dendrimer was able to change its structure by conformational changes in the flexible chains that link the mesogenic groups to the core. Structural change was seen under the application of a mean field ordering potential in the gas phase, and in the presence of liquid crystalline solvents. No liquid crystalline phases were observed for the bulk phase studies of the coarse-grained model. However, when the length of the mesogenic units was increased there was some evidence for microphase separation in these systems. (author)

  12. Molecular Mechanism Underlying Lymphatic Metastasis in Pancreatic Cancer

    Directory of Open Access Journals (Sweden)

    Zhiwen Xiao

    2014-01-01

    Full Text Available As the most challenging human malignancies, pancreatic cancer is characterized by its insidious symptoms, low rate of surgical resection, high risk of local invasion, metastasis and recurrence, and overall dismal prognosis. Lymphatic metastasis, above all, is recognized as an early adverse event in progression of pancreatic cancer and has been described to be an independent poor prognostic factor. It should be noted that the occurrence of lymphatic metastasis is not a casual or stochastic but an ineluctable and designed event. Increasing evidences suggest that metastasis-initiating cells (MICs and the microenvironments may act as a double-reed style in this crime. However, the exact mechanisms on how they function synergistically for this dismal clinical course remain largely elusive. Therefore, a better understanding of its molecular and cellular mechanisms involved in pancreatic lymphatic metastasis is urgently required. In this review, we will summarize the latest advances on lymphatic metastasis in pancreatic cancer.

  13. The levels of processing effect under nitrogen narcosis.

    Science.gov (United States)

    Kneller, Wendy; Hobbs, Malcolm

    2013-01-01

    Previous research has consistently demonstrated that inert gas (nitrogen) narcosis affects free recall but not recognition memory in the depth range of 30 to 50 meters of sea water (msw), possibly as a result of narcosis preventing processing when learned material is encoded. The aim of the current research was to test this hypothesis by applying a levels of processing approach to the measurement of free recall under narcosis. Experiment 1 investigated the effect of depth (0-2 msw vs. 37-39 msw) and level of processing (shallow vs. deep) on free recall memory performance in 67 divers. When age was included as a covariate, recall was significantly worse in deep water (i.e., under narcosis), compared to shallow water, and was significantly higher in the deep processing compared to shallow processing conditions in both depth conditions. Experiment 2 demonstrated that this effect was not simply due to the different underwater environments used for the depth conditions in Experiment 1. It was concluded memory performance can be altered by processing under narcosis and supports the contention that narcosis affects the encoding stage of memory as opposed to self-guided search (retrieval).

  14. Renormalized molecular levels in a Sc3N@C-80 molecular electronic device

    DEFF Research Database (Denmark)

    Larade, Brian; Taylor, Jeremy Philip; Zheng, Q. R.

    2001-01-01

    We address several general questions about quantum transport through molecular systems by an ab initio analysis of a scandium-nitrogen doped C-80 metallofullerene device. Charge transfer from the Sc3N is found to drastically change the current-voltage characteristics: the current through the Sc3N...... @ C-80 device is double that through a bare C-80 device. We provide strong evidence that transport in such molecular devices is mediated by molecular electronic states which have been renormalized by the device environment, such as the electrodes and external bias V-b. The renormalized molecular...

  15. Physiological and molecular changes in barley and wheat under salinity.

    Science.gov (United States)

    Temel, Aslihan; Gozukirmizi, Nermin

    2015-03-01

    In this study, it was aimed to compare salinity-induced changes in barley (Hordeum vulgare L. cv. Bornova-92) and bread wheat (Triticum aestivum L. cv. Gerek-79). Seeds were germinated under saline conditions (0, 50, 100, 250, and 500 mM NaCl) for 2 days and recovered under non-saline conditions for 2 days. At the end of the salt treatment, germination, water content (WC), total soluble protein content, and catalase (CAT, EC 1.11.1.6) activity were affected in both species, while superoxide dismutase (SOD, EC 1.15.1.1) activity was affected in barley. Salinity affected WC, protein content, and CAT activity in both species, while it affected germination in barley and affected fresh weight and SOD activity in wheat after recovery. Physiological responses of both species were correlated. Expression of α-tubulin, Atls1, and Lls1 genes was down-regulated in barley after 250 mM NaCl treatment. HVA1 gene was highly (more than 50-fold) stimulated by salinity in barley. However, α-tubulin and Atls1 genes were down-regulated, and Lls1 gene was up-regulated in wheat after recovery from 250-mM NaCl treatment. Increase in HVA1 expression was not significant in wheat. The expression profiles of barley and wheat under salinity are different, and barley tended to regulate gene expression faster than wheat.

  16. The thermodynamics of molecular cloud fragmentation : Star formation under non-Milky Way conditions

    NARCIS (Netherlands)

    Hocuk, S.; Spaans, M.

    Context. Properties of candidate stars, forming out of molecular clouds, depend on the ambient conditions of the parent cloud. We present a series of 2D and 3D simulations of fragmentation of molecular clouds in starburst regions, as well as of clouds under conditions in dwarf galaxies, leading to

  17. Noise-Immune Cavity-Enhanced Optical Heterodyne Molecular Spectrometry Modelling Under Saturated Absorption

    Science.gov (United States)

    Dupré, Patrick

    2015-06-01

    The Noise-Immune Cavity-Enhanced Optical Heterodyne Molecular Spectrometry (NICE-OHMS) is a modern technique renowned for its ultimate sensitivity, because it combines long equivalent absorption length provided by a high finesse cavity, and a detection theoretically limited by the sole photon-shot-noise. One fallout of the high finesse is the possibility to accumulating strong intracavity electromagnetic fields (EMF). Under this condition, molecular transitions can be easy saturated giving rise to the usual Lamb dips (or hole burning). However, the unusual shape of the basically trichromatic EMF (due to the RF lateral sidebands) induces nonlinear couplings, i.e., new crossover transitions. An analytical methodology will be presented to calculate spectra provided by NICE-OHMS experiments. It is based on the solutions of the equations of motion of an open two-blocked-level system performed in the frequency-domain (optically thin medium). Knowing the transition dipole moment, the NICE-OHMS signals (``absorption-like'' and ``dispersion-like'') can be simulated by integration over the Doppler shifts and by paying attention to the molecular Zeeman sublevels and to the EMF polarization The approach has been validated by discussion experimental data obtained on two transitions of {C2H2} in the near-infrared under moderated saturation. One of the applications of the saturated absorption is to be able to simultaneously determine the transition intensity and the density number while only one these 2 quantities can only be assessed in nonlinear absorption. J. Opt. Soc. Am. B 32, 838 (2015) Optics Express 16, 14689 (2008)

  18. The molecular pathways underlying host resistance and tolerance to pathogens.

    Science.gov (United States)

    Glass, Elizabeth J

    2012-01-01

    Breeding livestock that are better able to withstand the onslaught of endemic- and exotic pathogens is high on the wish list of breeders and farmers world-wide. However, the defense systems in both pathogens and their hosts are complex and the degree of genetic variation in resistance and tolerance will depend on the trade-offs that they impose on host fitness as well as their life-histories. The genes and pathways underpinning resistance and tolerance traits may be distinct or intertwined as the outcome of any infection is a result of a balance between collateral damage of host tissues and control of the invading pathogen. Genes and molecular pathways associated with resistance are mainly expressed in the mucosal tract and the innate immune system and control the very early events following pathogen invasion. Resistance genes encode receptors involved in uptake of pathogens, as well as pattern recognition receptors (PRR) such as the toll-like receptor family as well as molecules involved in strong and rapid inflammatory responses which lead to rapid pathogen clearance, yet do not lead to immunopathology. In contrast tolerance genes and pathways play a role in reducing immunopathology or enhancing the host's ability to protect against pathogen associated toxins. Candidate tolerance genes may include cytosolic PRRs and unidentified sensors of pathogen growth, perturbation of host metabolism and intrinsic danger or damage associated molecules. In addition, genes controlling regulatory pathways, tissue repair and resolution are also tolerance candidates. The identities of distinct genetic loci for resistance and tolerance to infectious pathogens in livestock species remain to be determined. A better understanding of the mechanisms involved and phenotypes associated with resistance and tolerance should ultimately help to improve livestock health and welfare.

  19. The molecular pathways underlying host resistance and tolerance to pathogens

    Directory of Open Access Journals (Sweden)

    Elizabeth Janet Glass

    2012-12-01

    Full Text Available Breeding livestock that are better able to withstand the onslaught of endemic and exotic pathogens is high on the wish list of breeders and farmers world-wide. However the defence systems in both pathogens and their hosts are complex and the degree of genetic variation in resistance and tolerance will depend on the trade-offs that they impose on host fitness as well as their life-histories. The genes and pathways underpinning resistance and tolerance traits may be distinct or intertwined as the outcome of any infection is a result of a balance between collateral damage of host tissues and control of the invading pathogen. Genes and molecular pathways associated with resistance are mainly expressed in the mucosal tract and the innate immune system and control the very early events following pathogen invasion. Resistance genes encode receptors involved in uptake of pathogens, as well as pattern recognition receptors (PRR such as the toll-like receptor family as well as molecules involved in strong and rapid inflammatory responses which lead to rapid pathogen clearance yet do not lead to immunopathology. In contrast tolerance genes and pathways play a role in reducing immunopathology or enhancing the host’s ability to protect against pathogen associated toxins. Candidate tolerance genes may include cytosolic PRRs and unidentified sensors of pathogen growth, perturbation of host metabolism and intrinsic danger or damage associated molecules. In addition, genes controlling regulatory pathways, tissue repair and resolution are also tolerance candidates. The identities of distinct genetic loci for resistance and tolerance to infectious pathogens in livestock species remain to be determined. A better understanding of the mechanisms involved and phenotypes associated with resistance and tolerance should ultimately help to improve livestock health and welfare.

  20. Tear film lipid layer: A molecular level view

    Czech Academy of Sciences Publication Activity Database

    Cwiklik, Lukasz

    2016-01-01

    Roč. 1858, č. 10 (2016), s. 2421-2430 ISSN 0005-2736 R&D Projects: GA ČR GA15-14292S Institutional support: RVO:61388955 Keywords : tear film * tear film lipid layer * molecular dynamics simulations Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.498, year: 2016

  1. A hypothesis regarding the molecular mechanism underlying dietary soy-induced effects on seizure propensity.

    Directory of Open Access Journals (Sweden)

    Cara Jean Westmark

    2014-09-01

    Full Text Available Numerous neurological disorders including fragile X syndrome, Down syndrome, autism and Alzheimer’s disease are comorbid with epilepsy. We have observed elevated seizure propensity in mouse models of these disorders dependent on diet. Specifically, soy-based diets exacerbate audiogenic-induced seizures in juvenile mice. We have also found potential associations between the consumption of soy-based infant formula and seizure incidence, epilepsy comorbidity and autism diagnostic scores in autistic children by retrospective analyses of medical record data. In total, these data suggest that consumption of high levels of soy protein during postnatal development may affect neuronal excitability. Herein, we present our theory regarding the molecular mechanism underlying soy-induced effects on seizure propensity. We hypothesize that soy phytoestrogens interfere with metabotropic glutamate receptor signaling through an estrogen receptor-dependent mechanism, which results in elevated production of key synaptic proteins and decreased seizure threshold.

  2. Molecular Mechanisms Underlying γ-Aminobutyric Acid (GABA) Accumulation in Giant Embryo Rice Seeds.

    Science.gov (United States)

    Zhao, Guo-Chao; Xie, Mi-Xue; Wang, Ying-Cun; Li, Jian-Yue

    2017-06-21

    To uncover the molecular mechanisms underlying GABA accumulation in giant embryo rice seeds, we analyzed the expression levels of GABA metabolism genes and contents of GABA and GABA metabolic intermediates in developing grains and germinated brown rice of giant embryo rice 'Shangshida No. 5' and normal embryo rice 'Chao2-10' respectively. In developing grains, the higher GABA contents in 'Shangshida No. 5' were accompanied with upregulation of gene transcripts and intermediate contents in the polyamine pathway and downregulation of GABA catabolic gene transcripts, as compared with those in 'Chao2-10'. In germinated brown rice, the higher GABA contents in 'Shangshida No. 5' were parallel with upregulation of OsGAD and polyamine pathway gene transcripts and Glu and polyamine pathway intermediate contents and downregulation of GABA catabolic gene transcripts. These results are the first to indicate that polyamine pathway and GABA catabolic genes play a crucial role in GABA accumulation in giant embryo rice seeds.

  3. Molecular-level Design of Heterogeneous Chiral Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Gellman, Andrew John [Carnegie Mellon University; Sholl, David S. [Georgia Institute of Technology; Tysoe, Wilfred T. [University of Wisconsin - Milwaukee; Zaera, Francisco [University of California at Riverside

    2013-04-28

    Understanding and controlling selectivity is one of the key challenges in heterogeneous catalysis. Among problems in catalytic selectivity enantioselectivity is perhaps the most the most challenging. The primary goal of the project on “Molecular-level Design of Heterogeneous Chiral Catalysts” is to understand the origins of enantioselectivity on chiral heterogeneous surfaces and catalysts. The efforts of the project team include preparation of chiral surfaces, characterization of chiral surfaces, experimental detection of enantioselectivity on such surfaces and computational modeling of the interactions of chiral probe molecules with chiral surfaces. Over the course of the project period the team of PI’s has made some of the most detailed and insightful studies of enantioselective chemistry on chiral surfaces. This includes the measurement of fundamental interactions and reaction mechanisms of chiral molecules on chiral surfaces and leads all the way to rationale design and synthesis of chiral surfaces and materials for enantioselective surface chemistry. The PI’s have designed and prepared new materials for enantioselective adsorption and catalysis. Naturally Chiral Surfaces • Completion of a systematic study of the enantiospecific desorption kinetics of R-3-methylcyclohexanone (R-3-MCHO) on 9 achiral and 7 enantiomeric pairs of chiral Cu surfaces with orientations that span the stereographic triangle. • Discovery of super-enantioselective tartaric acid (TA) and aspartic acid (Asp) decomposition as a result of a surface explosion mechanism on Cu(643)R&S. Systematic study of super-enantiospecific TA and Asp decomposition on five enantiomeric pairs of chiral Cu surfaces. • Initial observation of the enantiospecific desorption of R- and S-propylene oxide (PO) from Cu(100) imprinted with {3,1,17} facets by L-lysine adsorption. Templated Chiral Surfaces • Initial observation of the enantiospecific desorption of R- and S-PO from Pt(111) and Pd(111

  4. The distortion of the level set gradient under advection

    Science.gov (United States)

    Trujillo, Mario F.; Anumolu, Lakshman; Ryddner, Doug

    2017-04-01

    The practice of periodically reinitializing the level set function is well established in two-phase flow applications as a way of controlling the growth of anomalies and/or numerical errors. In the present work, the underlying roots of this anomalous growth are studied, where it is established that the augmentation of the magnitude of the level set gradient (| ∇ϕ |) is directly connected to the nature of the flow field; hence, it is not necessarily the result of some type of numerical error. More specifically, for a general flow field advecting the level set function, it is shown that the eigenpairs of the strain rate tensor are responsible for the rate of change of | ∇ϕ | along a fluid particle trajectory. This straining action not only affects the magnitude of | ∇ϕ |, but the general character of ϕ, and consequently contributes to the growth in numerical error. These numerical consequences are examined by adopting the Gradient Augmented Level Set method. Specifically, it is shown that the local error for ϕ is directly connected to the size of | ∇ϕ | and to the magnitude of the second and fourth order derivatives of ϕ. These analytical findings are subsequently supported by various examples. The role of reinitialization is discussed, where it is shown that in cases where the zero level set contour has a local radius of curvature that is below the local grid resolution, reinitialization exacerbates rather than diminishes the degree of error. For other cases, where the interface is well resolved, reinitialization helps stabilize the error as intended.

  5. Improving Molecular Level Chemical Speciation of Organic Aerosols

    Science.gov (United States)

    Worton, D. R.; Decker, M.; Isaacman, G. A.; Chan, A.; Wilson, K. R.; Goldstein, A. H.

    2013-12-01

    A substantial fraction of fine mode aerosols are organic with the majority formed in the atmosphere through oxidation of gas phase compounds emitted from a variety of natural and man-made sources. As a result, organic aerosols are comprised of thousands of individual organic species whose complexity increases exponentially with carbon number and degree of atmospheric oxidation. Chemical characterization of individual compounds present in this complex mixture provides information on sources and transformation processes that are critical for apportioning organic carbon from an often convoluted mixture of sources and to constrain oxidation mechanisms needed for atmospheric models. These compounds also affect the physical and optical properties of the aerosol but the vast majority remain unidentified and missing from published mass spectral libraries because of difficulties in separating and identifying them. We have developed improved methodologies for chemical identification in order to better understand complex environmental mixtures. Our approach has been to combine two-dimensional gas chromatography with high resolution time of flight mass spectrometry (GC×GC-HRTOFMS) and both traditional electron ionization (EI) and vacuum ultraviolet (VUV) photoionization. GC×GC provides improved separation of individual compounds over traditional one dimensional GC and minimizes co-elution of peaks resulting in mass spectra that are virtually free of interferences. VUV ionization is a ';soft' ionization technique that reduces fragmentation and enhances the abundance of the parent or molecular ion, which when combined with high resolution mass spectrometry can provide molecular formulas for chromatographic peaks. We demonstrate our methodology by applying it to identify more than 500 individual compounds in aerosol filter samples collected at Blodgett Forest, a rural site in the Sierra Nevada Mountains. Using the EI NIST mass spectral library and molecular formulas determined

  6. Physiological and molecular alterations in plants exposed to high [CO2] under phosphorus stress.

    Science.gov (United States)

    Pandey, Renu; Zinta, Gaurav; AbdElgawad, Hamada; Ahmad, Altaf; Jain, Vanita; Janssens, Ivan A

    2015-01-01

    Atmospheric [CO2] has increased substantially in recent decades and will continue to do so, whereas the availability of phosphorus (P) is limited and unlikely to increase in the future. P is a non-renewable resource, and it is essential to every form of life. P is a key plant nutrient controlling the responsiveness of photosynthesis to [CO2]. Increases in [CO2] typically results in increased biomass through stimulation of net photosynthesis, and hence enhance the demand for P uptake. However, most soils contain low concentrations of available P. Therefore, low P is one of the major growth-limiting factors for plants in many agricultural and natural ecosystems. The adaptive responses of plants to [CO2] and P availability encompass alterations at morphological, physiological, biochemical and molecular levels. In general low P reduces growth, whereas high [CO2] enhances it particularly in C3 plants. Photosynthetic capacity is often enhanced under high [CO2] with sufficient P supply through modulation of enzyme activities involved in carbon fixation such as ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). However, high [CO2] with low P availability results in enhanced dry matter partitioning towards roots. Alterations in below-ground processes including root morphology, exudation and mycorrhizal association are influenced by [CO2] and P availability. Under high P availability, elevated [CO2] improves the uptake of P from soil. In contrast, under low P availability, high [CO2] mainly improves the efficiency with which plants produce biomass per unit P. At molecular level, the spatio-temporal regulation of genes involved in plant adaptation to low P and high [CO2] has been studied individually in various plant species. Genome-wide expression profiling of high [CO2] grown plants revealed hormonal regulation of biomass accumulation through complex transcriptional networks. Similarly, differential transcriptional regulatory networks are involved in P

  7. A Complex Approach for Unravelling Musaceae Phylogeny at Molecular Level

    Czech Academy of Sciences Publication Activity Database

    Němcová, Pavla; Hřibová, Eva; Valárik, Miroslav; Doležel, Jaroslav

    2011-01-01

    Roč. 897, SEP 14 (2011), s. 139-142 ISSN 0567-7572. [INTERNATIONAL ISHS-PROMUSA SYMPOSIUM ON GLOBAL PERSPECTIVES ON ASIAN CHALLENGES. Guangzhou, 14.08.2009-16.08.2009] R&D Projects: GA AV ČR IAA600380703 Institutional support: RVO:61389030 Keywords : DArT * low-copy genes * molecular phylogenetic s Subject RIV: EF - Botanics http://www.actahort.org/books/897/897_14.htm

  8. Status of Safeguards and Separations Model Development at Plant and Molecular Levels

    Energy Technology Data Exchange (ETDEWEB)

    de Almeida, Valmor F [ORNL; Hay, Benjamin [ORNL; DePaoli, David W [ORNL

    2009-10-01

    A primary goal of the Safeguards and Separations IPSC effort is the development of process modeling tools that allow dynamic simulations of separations plant operations under various configurations and conditions, and integration of relevant safeguards analyses. A requirement of the effort is to develop codes on modern, expandable architectures, with flexibility to explore and evaluate a wide range of process options. During FY09, efforts at ORNL have been focused on two priority tasks toward achieving the IPSC goal: (1) a top-down exploration of architecture - Subtask 1: Explore framework for code development and integration for plant-level simulation; and (2) a bottom-up fundamental modeling effort - Subtask 2: Development of molecular-level agent design code. Subtask 1 is important because definition and development of architecture is a key issue for the overall effort, as selection of an overall approach and code/data requirements is a necessary first step in the organization, design and development of separations and safeguards codes that will be incorporated. The agent design effort of Subtask 2 is a molecular-level modeling effort that has a direct impact on a near-term issue of the Separations and Waste Forms Campaign. A current focus of experimental efforts is the development of robust agents and processes for separation of Am/Cm. Development of enhanced agent-design codes will greatly accelerate discovery and experimental testing.

  9. Status of Safeguards and Separations Model Development at Plant and Molecular Levels

    International Nuclear Information System (INIS)

    de Almeida, Valmor F.; Hay, Benjamin; DePaoli, David W.

    2009-01-01

    A primary goal of the Safeguards and Separations IPSC effort is the development of process modeling tools that allow dynamic simulations of separations plant operations under various configurations and conditions, and integration of relevant safeguards analyses. A requirement of the effort is to develop codes on modern, expandable architectures, with flexibility to explore and evaluate a wide range of process options. During FY09, efforts at ORNL have been focused on two priority tasks toward achieving the IPSC goal: (1) a top-down exploration of architecture - Subtask 1: Explore framework for code development and integration for plant-level simulation; and (2) a bottom-up fundamental modeling effort - Subtask 2: Development of molecular-level agent design code. Subtask 1 is important because definition and development of architecture is a key issue for the overall effort, as selection of an overall approach and code/data requirements is a necessary first step in the organization, design and development of separations and safeguards codes that will be incorporated. The agent design effort of Subtask 2 is a molecular-level modeling effort that has a direct impact on a near-term issue of the Separations and Waste Forms Campaign. A current focus of experimental efforts is the development of robust agents and processes for separation of Am/Cm. Development of enhanced agent-design codes will greatly accelerate discovery and experimental testing.

  10. Production of tropical forage grasses under different shading levels

    Directory of Open Access Journals (Sweden)

    Francisco Eduardo Torres

    2017-12-01

    Full Text Available This study aimed to evaluate the forage production of three tropical forage grasses under different shading levels. The experiment was conducted in a greenhouse at Universidade Estadual de Mato Grosso do Sul, University Unit of Aquidauana (UEMS/UUA, in a soil classified as Ultisol sandy loam texture. The treatments consisted of three grasses species combinations (B. brizantha cv. Marandu, B. decumbens cv. Basilisck and Panicum maximum cv. Tanzania, submitted to four shading levels (0, 30, 50 and 75%, arranged in a completely randomized blocks design in a factorial 3 x 4, with eight replications. After harvest, the plants were separated into shoot and roots for determination of shoot fresh mass (SFM, shoot dry mass (SDM and roots dry mass production. After analysis of variance, the qualitative factor was subjected to comparison of averages by Tukey’s test, and the quantitative factor to analysis of polynomial regression, being interactions appropriately unfolded. It was verified that B. decumbens, by its linearly increasing production of forage and less decrease of root formation, is the most recommended for shading conditions compared to grasses Tanzania and Marandu.

  11. [International research trends of pharmacognosy on molecular level --based on analysis of SCI literature].

    Science.gov (United States)

    Zhang, Bin; Li, Hai-Yan; Liu, Xiao-Ting; Tang, Xiao-Li

    2016-02-01

    The techniques and methods of molecular biology have been widely applied in pharmacognosy fields. International development trends of pharmacognosy studies on molecular level were analyzed by bibliometric methods using the SCIE database on Web of Science, the literature distribution, national distribution, agency distribution, periodicals distribution, and hot research topics were described using multivariate statistical analysis and multidimensional scaling analysis method,etc. The number of international pharmacognosy literature on molecular level is increasing year by year. USA, China and Japan have close cooperation, and focus on molecular identification and genetic diversity. Chinese scientists issued high-impact factor journals papers and high citations amount in the international forefront. The international pharmacognosy research on molecular level has developed rapidly. Chinese research has a significant influence.The molecular mechanism of the formation of Dao-di Herbs may become the next hotspot. Copyright© by the Chinese Pharmaceutical Association.

  12. Organization of lipids in the tear film: a molecular-level view.

    Directory of Open Access Journals (Sweden)

    Alicja Wizert

    Full Text Available Biophysical properties of the tear film lipid layer are studied at the molecular level employing coarse grain molecular dynamics (MD simulations with a realistic model of the human tear film. In this model, polar lipids are chosen to reflect the current knowledge on the lipidome of the tear film whereas typical Meibomian-origin lipids are included in the thick non-polar lipids subphase. Simulation conditions mimic those experienced by the real human tear film during blinks. Namely, thermodynamic equilibrium simulations at different lateral compressions are performed to model varying surface pressure, and the dynamics of the system during a blink is studied by non-equilibrium MD simulations. Polar lipids separate their non-polar counterparts from water by forming a monomolecular layer whereas the non-polar molecules establish a thick outermost lipid layer. Under lateral compression, the polar layer undulates and a sorting of polar lipids occurs. Moreover, formation of three-dimensional aggregates of polar lipids in both non-polar and water subphases is observed. We suggest that these three-dimensional structures are abundant under dynamic conditions caused by the action of eye lids and that they act as reservoirs of polar lipids, thus increasing stability of the tear film.

  13. Organization of Lipids in the Tear Film: A Molecular-Level View

    Science.gov (United States)

    Wizert, Alicja; Iskander, D. Robert; Cwiklik, Lukasz

    2014-01-01

    Biophysical properties of the tear film lipid layer are studied at the molecular level employing coarse grain molecular dynamics (MD) simulations with a realistic model of the human tear film. In this model, polar lipids are chosen to reflect the current knowledge on the lipidome of the tear film whereas typical Meibomian-origin lipids are included in the thick non-polar lipids subphase. Simulation conditions mimic those experienced by the real human tear film during blinks. Namely, thermodynamic equilibrium simulations at different lateral compressions are performed to model varying surface pressure, and the dynamics of the system during a blink is studied by non-equilibrium MD simulations. Polar lipids separate their non-polar counterparts from water by forming a monomolecular layer whereas the non-polar molecules establish a thick outermost lipid layer. Under lateral compression, the polar layer undulates and a sorting of polar lipids occurs. Moreover, formation of three-dimensional aggregates of polar lipids in both non-polar and water subphases is observed. We suggest that these three-dimensional structures are abundant under dynamic conditions caused by the action of eye lids and that they act as reservoirs of polar lipids, thus increasing stability of the tear film. PMID:24651175

  14. Experimental models of communication at the molecular and microsystemic levels.

    Science.gov (United States)

    Fox, S. W.; Hsu, L.; Brooke, S.; Nakashima, T.; Lacey, J. C., Jr.

    1972-01-01

    Communication at both the macromolecular and the (supramacromolecular) microsystemic levels has been demonstrated in artificial polymers and artificial systems. These phenomena are models for communication in evolving and contemporary systems. The significance of a combination of communication at the two levels is emphasized.

  15. Radiation damage at the molecular level: Nanodosimetry; Dano por radiacion a nivel molecular: nanodosimetria

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, F.; Munoz, A.; Lagares, J. I.; Nunez, L.; Garcia, G.

    2013-07-01

    One of the main practical use of the model is its use as a tool of nanodosimetry which basically consists in characterizing the effect of radiation on nano volumes (comparable to the DNA of volumes) in terms of link breaks and molecular dissociations. (Author)

  16. Proteomic-Biostatistic Integrated Approach for Finding the Underlying Molecular Determinants of Hypertension in Human Plasma.

    Science.gov (United States)

    Gajjala, Prathibha R; Jankowski, Vera; Heinze, Georg; Bilo, Grzegorz; Zanchetti, Alberto; Noels, Heidi; Liehn, Elisa; Perco, Paul; Schulz, Anna; Delles, Christian; Kork, Felix; Biessen, Erik; Narkiewicz, Krzysztof; Kawecka-Jaszcz, Kalina; Floege, Juergen; Soranna, Davide; Zidek, Walter; Jankowski, Joachim

    2017-08-01

    Despite advancements in lowering blood pressure, the best approach to lower it remains controversial because of the lack of information on the molecular basis of hypertension. We, therefore, performed plasma proteomics of plasma from patients with hypertension to identify molecular determinants detectable in these subjects but not in controls and vice versa. Plasma samples from hypertensive subjects (cases; n=118) and controls (n=85) from the InGenious HyperCare cohort were used for this study and performed mass spectrometric analysis. Using biostatistical methods, plasma peptides specific for hypertension were identified, and a model was developed using least absolute shrinkage and selection operator logistic regression. The underlying peptides were identified and sequenced off-line using matrix-assisted laser desorption ionization orbitrap mass spectrometry. By comparison of the molecular composition of the plasma samples, 27 molecular determinants were identified differently expressed in cases from controls. Seventy percent of the molecular determinants selected were found to occur less likely in hypertensive patients. In cross-validation, the overall R 2 was 0.434, and the area under the curve was 0.891 with 95% confidence interval 0.8482 to 0.9349, P hypertensive patients were found to be -2.007±0.3568 and 3.383±0.2643, respectively, P hypertensives and normotensives. The identified molecular determinants may be the starting point for further studies to clarify the molecular causes of hypertension. © 2017 American Heart Association, Inc.

  17. Testing of high-level waste forms under repository conditions

    International Nuclear Information System (INIS)

    Mc Menamin, T.

    1989-01-01

    The workshop on testing of high-level waste forms under repository conditions was held on 17 to 21 October 1988 in Cadarache, France, and sponsored by the Commission of the European Communities (CEC), the Commissariat a l'energie atomique (CEA) and the Savannah River Laboratory (US DOE). Participants included representatives from Australia, Belgium, Denmark, France, Germany, Italy, Japan, the Netherlands, Sweden, Switzerland, The United Kingdom and the United States. The first part of the conference featured a workshop on in situ testing of simulated nuclear waste forms and proposed package components, with an emphasis on the materials interface interactions tests (MIIT). MIIT is a sevent-part programme that involves field testing of 15 glass and waste form systems supplied by seven countries, along with potential canister and overpack materials as well as geologic samples, in the salt geology at the Waste Isolation Pilot Plant (WIPP) in Carlsbad, New Mexico, USA. This effort is still in progress and these proceedings document studies and findings obtained thus far. The second part of the meeting emphasized multinational experimental studies and results derived from repository systems simulation tests (RSST), which were performed in granite, clay and salt environments

  18. Molecular Mechanistic Reasoning: Toward Bridging the Gap between the Molecular and Cellular Levels in Life Science Education

    Science.gov (United States)

    van Mil, Marc H. W.; Postma, Paulien A.; Boerwinkel, Dirk Jan; Klaassen, Kees; Waarlo, Arend Jan

    2016-01-01

    Although learning about DNA, RNA, and proteins is part of the upper secondary biology curriculum in most countries, many studies report that students fail to connect molecular knowledge to phenomena at the higher level of cells, organs, and organisms. As a result, many students use memorization and rote learning as a coping strategy when presented…

  19. Elucidation of the molecular mechanisms underlying adverse reactions associated with a kinase inhibitor using systems toxicology.

    Science.gov (United States)

    Amemiya, Takahiro; Honma, Masashi; Kariya, Yoshiaki; Ghosh, Samik; Kitano, Hiroaki; Kurachi, Yoshihisa; Fujita, Ken-Ichi; Sasaki, Yasutsuna; Homma, Yukio; Abernethy, Darrel R; Kume, Haruki; Suzuki, Hiroshi

    2015-01-01

    Targeted kinase inhibitors are an important class of agents in anticancer therapeutics, but their limited tolerability hampers their clinical performance. Identification of the molecular mechanisms underlying the development of adverse reactions will be helpful in establishing a rational method for the management of clinically adverse reactions. Here, we selected sunitinib as a model and demonstrated that the molecular mechanisms underlying the adverse reactions associated with kinase inhibitors can efficiently be identified using a systems toxicological approach. First, toxicological target candidates were short-listed by comparing the human kinase occupancy profiles of sunitinib and sorafenib, and the molecular mechanisms underlying adverse reactions were predicted by sequential simulations using publicly available mathematical models. Next, to evaluate the probability of these predictions, a clinical observation study was conducted in six patients treated with sunitinib. Finally, mouse experiments were performed for detailed confirmation of the hypothesized molecular mechanisms and to evaluate the efficacy of a proposed countermeasure against adverse reactions to sunitinib. In silico simulations indicated the possibility that sunitinib-mediated off-target inhibition of phosphorylase kinase leads to the generation of oxidative stress in various tissues. Clinical observations of patients and mouse experiments confirmed the validity of this prediction. The simulation further suggested that concomitant use of an antioxidant may prevent sunitinib-mediated adverse reactions, which was confirmed in mouse experiments. A systems toxicological approach successfully predicted the molecular mechanisms underlying clinically adverse reactions associated with sunitinib and was used to plan a rational method for the management of these adverse reactions.

  20. Estimating sea-level allowances for Atlantic Canada under conditions of uncertain sea-level rise

    Directory of Open Access Journals (Sweden)

    B. Greenan

    2015-03-01

    Full Text Available This paper documents the methodology of computing sea-level rise allowances for Atlantic Canada in the 21st century under conditions of uncertain sea-level rise. The sea-level rise allowances are defined as the amount by which an asset needs to be raised in order to maintain the same likelihood of future flooding events as that site has experienced in the recent past. The allowances are determined by combination of the statistics of present tides and storm surges (storm tides and the regional projections of sea-level rise and associated uncertainty. Tide-gauge data for nine sites from the Canadian Atlantic coast are used to derive the scale parameters of present sea-level extremes using the Gumbel distribution function. The allowances in the 21st century, with respect to the year 1990, were computed for the Intergovernmental Panel on Climate Change (IPCC A1FI emission scenario. For Atlantic Canada, the allowances are regionally variable and, for the period 1990–2050, range between –13 and 38 cm while, for the period 1990–2100, they range between 7 and 108 cm. The negative allowances in the northern Gulf of St. Lawrence region are caused by land uplift due to glacial isostatic adjustment (GIA.

  1. Estimating sea-level allowances for Atlantic Canada under conditions of uncertain sea-level rise

    Science.gov (United States)

    Greenan, B.; Zhai, L.; Hunter, J.; James, T. S.; Han, G.

    2015-03-01

    This paper documents the methodology of computing sea-level rise allowances for Atlantic Canada in the 21st century under conditions of uncertain sea-level rise. The sea-level rise allowances are defined as the amount by which an asset needs to be raised in order to maintain the same likelihood of future flooding events as that site has experienced in the recent past. The allowances are determined by combination of the statistics of present tides and storm surges (storm tides) and the regional projections of sea-level rise and associated uncertainty. Tide-gauge data for nine sites from the Canadian Atlantic coast are used to derive the scale parameters of present sea-level extremes using the Gumbel distribution function. The allowances in the 21st century, with respect to the year 1990, were computed for the Intergovernmental Panel on Climate Change (IPCC) A1FI emission scenario. For Atlantic Canada, the allowances are regionally variable and, for the period 1990-2050, range between -13 and 38 cm while, for the period 1990-2100, they range between 7 and 108 cm. The negative allowances in the northern Gulf of St. Lawrence region are caused by land uplift due to glacial isostatic adjustment (GIA).

  2. Time-Series Analyses of Transcriptomes and Proteomes Reveal Molecular Networks Underlying Oil Accumulation in Canola.

    Science.gov (United States)

    Wan, Huafang; Cui, Yixin; Ding, Yijuan; Mei, Jiaqin; Dong, Hongli; Zhang, Wenxin; Wu, Shiqi; Liang, Ying; Zhang, Chunyu; Li, Jiana; Xiong, Qing; Qian, Wei

    2016-01-01

    Understanding the regulation of lipid metabolism is vital for genetic engineering of canola ( Brassica napus L.) to increase oil yield or modify oil composition. We conducted time-series analyses of transcriptomes and proteomes to uncover the molecular networks associated with oil accumulation and dynamic changes in these networks in canola. The expression levels of genes and proteins were measured at 2, 4, 6, and 8 weeks after pollination (WAP). Our results show that the biosynthesis of fatty acids is a dominant cellular process from 2 to 6 WAP, while the degradation mainly happens after 6 WAP. We found that genes in almost every node of fatty acid synthesis pathway were significantly up-regulated during oil accumulation. Moreover, significant expression changes of two genes, acetyl-CoA carboxylase and acyl-ACP desaturase, were detected on both transcriptomic and proteomic levels. We confirmed the temporal expression patterns revealed by the transcriptomic analyses using quantitative real-time PCR experiments. The gene set association analysis show that the biosynthesis of fatty acids and unsaturated fatty acids are the most significant biological processes from 2-4 WAP and 4-6 WAP, respectively, which is consistent with the results of time-series analyses. These results not only provide insight into the mechanisms underlying lipid metabolism, but also reveal novel candidate genes that are worth further investigation for their values in the genetic engineering of canola.

  3. Molecular sieve sensors for selective detection at the nanogram level

    Science.gov (United States)

    Bein, Thomas; Brown, Kelly D.; Frye, Gregory C.; Brinker, Charles J.

    1992-01-01

    The invention relates to a selective chemical sensor for selective detection of chemical entities even at the nanogram level. The invention further relates to methods of using the sensor. The sensor comprises: (a) a piezoelectric substrate capable of detecting mass changes resulting from adsorption of material thereon; and (b) a coating applied to the substrate, which selectively sorbs chemical entities of a size smaller than a preselected magnitude.

  4. The challenges for molecular nutrition research 4: the "nutritional systems biology level"

    NARCIS (Netherlands)

    Ommen, B. van; Cavallieri, D.; Roche, H.M.; Klein, U.I.; Daniel, H.

    2008-01-01

    Nutritional systems biology may be defined as the ultimate goal of molecular nutrition research, where all relevant aspects of regulation of metabolism in health and disease states at all levels of its complexity are taken into account to describe the molecular physiology of nutritional processes.

  5. Molecular-Level Design of Heterogeneous Chiral Catalysis

    International Nuclear Information System (INIS)

    Zaera, Francisco

    2012-01-01

    , and the development of ways to imprint chiral centers on achiral solid surfaces. Chiral catalysis is not only a problem of great importance in its own right, but also the ultimate test of how to control selectivity in catalysis. The time is ripe for fundamental work in heterogeneous chiral catalysis to provide the U.S. with a leadership role in developing the next generation of catalytic processes for medicinal and agrochemical manufacturing. Our team provides the required expertise for a synergistic and comprehensive integration of physical and chemical experimentation with solid state and molecular reactivity theories to solve this problem.

  6. Molecular-Level Design of Heterogeneous Chiral Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Francisco Zaera

    2012-03-21

    , and the development of ways to imprint chiral centers on achiral solid surfaces. Chiral catalysis is not only a problem of great importance in its own right, but also the ultimate test of how to control selectivity in catalysis. The time is ripe for fundamental work in heterogeneous chiral catalysis to provide the U.S. with a leadership role in developing the next generation of catalytic processes for medicinal and agrochemical manufacturing. Our team provides the required expertise for a synergistic and comprehensive integration of physical and chemical experimentation with solid state and molecular reactivity theories to solve this problem.

  7. Molecular mechanisms underlying synergistic adhesion of sickle red blood cells by hypoxia and low nitric oxide bioavailability.

    Science.gov (United States)

    Gutsaeva, Diana R; Montero-Huerta, Pedro; Parkerson, James B; Yerigenahally, Shobha D; Ikuta, Tohru; Head, C Alvin

    2014-03-20

    The molecular mechanisms by which nitric oxide (NO) bioavailability modulates the clinical expression of sickle cell disease (SCD) remain elusive. We investigated the effect of hypoxia and NO bioavailability on sickle red blood cell (sRBC) adhesion using mice deficient for endothelial NO synthase (eNOS) because their NO metabolite levels are similar to those of SCD mice but without hypoxemia. Whereas sRBC adhesion to endothelial cells in eNOS-deficient mice was synergistically upregulated at the onset of hypoxia, leukocyte adhesion was unaffected. Restoring NO metabolite levels to physiological levels markedly reduced sRBC adhesion to levels seen under normoxia. These results indicate that sRBC adherence to endothelial cells increases in response to hypoxia prior to leukocyte adherence, and that low NO bioavailability synergistically upregulates sRBC adhesion under hypoxia. Although multiple adhesion molecules mediate sRBC adhesion, we found a central role for P-selectin in sRBC adhesion. Hypoxia and low NO bioavailability upregulated P-selectin expression in endothelial cells in an additive manner through p38 kinase pathways. These results demonstrate novel cellular and signaling mechanisms that regulate sRBC adhesion under hypoxia and low NO bioavailability. Importantly, these findings point us toward new molecular targets to inhibit cell adhesion in SCD.

  8. Direct molecular-level characterization of different heterogeneous freezing modes on mica - Part 1

    Science.gov (United States)

    Abdelmonem, Ahmed

    2017-09-01

    The mechanisms behind heterogeneous ice nucleation are of fundamental importance to the prediction of the occurrence and properties of many cloud types, which influence climate and precipitation. Aerosol particles act as cloud condensation and freezing nuclei. The surface-water interaction of an ice nucleation particle plays a major, not well explored, role in its ice nucleation ability. This paper presents a real-time molecular-level comparison of different freezing modes on the surface of an atmospherically relevant mineral surface (mica) under varying supersaturation conditions using second-harmonic generation spectroscopy. Two sub-deposition nucleation modes were identified (one- and two-stage freezing). The nonlinear signal at the water-mica interface was found to drop following the formation of a thin film on the surface regardless of (1) the formed phase (liquid or ice) and (2) the freezing path (one or two step), indicating similar molecular structuring. The results also revealed a transient phase of ice at water-mica interfaces during freezing, which has a lifetime of around 1 min. Such information will have a significant impact on climate change, weather modification, and the tracing of water in hydrosphere studies.

  9. Molecular orientation behavior of isotactic polypropylene under uniaxial stretching by rheo-Raman spectroscopy

    Directory of Open Access Journals (Sweden)

    T. Kida

    2016-08-01

    Full Text Available The molecular orientation behavior of isotactic polypropylene (iPP is investigated by using in situ Raman spectroscopy under tensile tests. A versatile method of the tilt-angle correction for the orientation parameters is newly developed, where the molecular orientation in highly oriented specimens is assumed to be entropically favorable. The real-time changes of orientation parameters and orientation distribution functions are determined for the molecular chain axis of iPP during uniaxial stretching. The molecular orientation remains random in the elastic region, and increases after the first yield point. In the yielding region, a broad distribution of orientation toward an intermediate angle of 30–70° from the stretching direction is observed. This is interpreted as reorientation of the crystalline chains being hindered by rigid, bulky lamellar cluster units. After the yielding region, orientation toward the stretching direction proceeds rapidly, approaching highly oriented states.

  10. Foundational Concepts and Underlying Theories for Majors in "Biochemistry and Molecular Biology"

    Science.gov (United States)

    Tansey, John T.; Baird, Teaster, Jr.; Cox, Michael M.; Fox, Kristin M.; Knight, Jennifer; Sears, Duane; Bell, Ellis

    2013-01-01

    Over the past two years, through an NSF RCN UBE grant, the ASBMB has held regional workshops for faculty members and science educators from around the country that focused on identifying: 1) core principles of biochemistry and molecular biology, 2) essential concepts and underlying theories from physics, chemistry, and mathematics, and 3)…

  11. Improved Inhibition of Telomerase by Short Twisted Intercalating Nucleic Acids under Molecular Crowding Conditions

    DEFF Research Database (Denmark)

    Agarwal, Tani; Pradhan, Devranjan; Géci, Imrich

    2012-01-01

    Human telomeric DNA has the ability to fold into a 4-stranded G-quadruplex structure. Several G-quadruplex ligands are known to stabilize the structure and thereby inhibit telomerase activity. Such ligands have demonstrated efficient telomerase inhibition in dilute conditions, but under molecular...

  12. Fermi level alignment in molecular nanojunctions and its relation to charge transfer

    DEFF Research Database (Denmark)

    Stadler, Robert; Jacobsen, Karsten Wedel

    2006-01-01

    by orders of magnitude. We present a quantitative analysis of the relation between this level alignment (which can be estimated from charging free molecules) and charge transfer for bipyridine and biphenyl dithiolate (BPDT) molecules attached to gold leads based on density functional theory calculations......The alignment of the Fermi level of a metal electrode within the gap of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of a molecule is a key quantity in molecular electronics, which can vary the electron transparency of a single-molecule junction...

  13. Computational Analysis of Molecular Interaction Networks Underlying Change of HIV-1 Resistance to Selected Reverse Transcriptase Inhibitors.

    Science.gov (United States)

    Kierczak, Marcin; Dramiński, Michał; Koronacki, Jacek; Komorowski, Jan

    2010-12-12

    Despite more than two decades of research, HIV resistance to drugs remains a serious obstacle in developing efficient AIDS treatments. Several computational methods have been developed to predict resistance level from the sequence of viral proteins such as reverse transcriptase (RT) or protease. These methods, while powerful and accurate, give very little insight into the molecular interactions that underly acquisition of drug resistance/hypersusceptibility. Here, we attempt at filling this gap by using our Monte Carlo feature selection and interdependency discovery method (MCFS-ID) to elucidate molecular interaction networks that characterize viral strains with altered drug resistance levels. We analyzed a number of HIV-1 RT sequences annotated with drug resistance level using the MCFS-ID method. This let us expound interdependency networks that characterize change of drug resistance to six selected RT inhibitors: Abacavir, Lamivudine, Stavudine, Zidovudine, Tenofovir and Nevirapine. The networks consider interdependencies at the level of physicochemical properties of mutating amino acids, eg,: polarity. We mapped each network on the 3D structure of RT in attempt to understand the molecular meaning of interacting pairs. The discovered interactions describe several known drug resistance mechanisms and, importantly, some previously unidentified ones. Our approach can be easily applied to a whole range of problems from the domain of protein engineering. A portable Java implementation of our MCFS-ID method is freely available for academic users and can be obtained at: http://www.ipipan.eu/staff/m.draminski/software.htm.

  14. two-level inventory optimization under probability event chain

    African Journals Online (AJOL)

    . ... Journal of Modeling, Design and Management of Engineering Systems ... It is shown that optimization and coordination of the safety factor lead to inventory cost savings at two sites, especially under large lead time variability and stock ...

  15. Nanopore wall-liquid interaction under scope of molecular dynamics study: Review

    Science.gov (United States)

    Tsukanov, A. A.; Psakhie, S. G.

    2017-12-01

    The present review is devoted to the analysis of recent molecular dynamics based on the numerical studies of molecular aspects of solid-fluid interaction in nanoscale channels. Nanopore wall-liquid interaction plays the crucial role in such processes as gas separation, water desalination, liquids decontamination, hydrocarbons and water transport in nano-fractured geological formations. Molecular dynamics simulation is one of the most suitable tools to study molecular level effects occurred in such multicomponent systems. The nanopores are classified by their geometry to four groups: nanopore in nanosheet, nanotube-like pore, slit-shaped nanopore and soft-matter nanopore. The review is focused on the functionalized nanopores in boron nitride nanosheets as novel selective membranes and on the slit-shaped nanopores formed by minerals.

  16. Putative molecular mechanism underlying sperm chromatin remodelling is regulated by reproductive hormones

    Directory of Open Access Journals (Sweden)

    Gill-Sharma Manjeet Kaur

    2012-12-01

    Full Text Available Abstract Background The putative regulatory role of the male reproductive hormones in the molecular mechanism underlying chromatin condensation remains poorly understood. In the past decade, we developed two adult male rat models wherein functional deficits of testosterone or FSH, produced after treatments with 20 mg/Kg/d of cyproterone acetate (CPA per os, for a period of 15 days or 3 mg/Kg/d of fluphenazine decanoate (FD subcutaneously, for a period of 60 days, respectively, affected the rate of sperm chromatin decondensation in vitro. These rat models have been used in the current study in order to delineate the putative roles of testosterone and FSH in the molecular mechanism underlying remodelling of sperm chromatin. Results We report that deficits of both testosterone and FSH affected the turnover of polyubiquitylated histones and led to their accumulation in the testis. Functional deficits of testosterone reduced expression of MIWI, the 5-methyl cap binding RNA-binding protein (PIWIlike murine homologue of the Drosophila protein PIWI/P-element induced wimpy testis containing a PAZ/Piwi-Argonaut-Zwille domain and levels of histone deacetylase1 (HDAC1, ubiquitin ligating enzyme (URE-B1/E3, 20S proteasome α1 concomitant with reduced expression of ubiquitin activating enzyme (ube1, conjugating enzyme (ube2d2, chromodomain Y like protein (cdyl, bromodomain testis specific protein (brdt, hdac6 (histone deacetylase6, androgen-dependent homeobox placentae embryonic protein (pem/RhoX5, histones h2b and th3 (testis-specific h3. Functional deficits of FSH reduced the expression of cdyl and brdt genes in the testis, affected turnover of ubiquitylated histones, stalled the physiological DNA repair mechanism and culminated in spermiation of DNA damaged sperm. Conclusions We aver that deficits of both testosterone and FSH differentially affected the process of sperm chromatin remodelling through subtle changes in the ‘chromatin condensation

  17. Price level versus inflation targeting under model uncertainty

    OpenAIRE

    Cateau, Gino

    2008-01-01

    The purpose of this paper is to make a quantitative contribution to the inflation versus price level targeting debate. It considers a policy-maker that can set policy either through an inflation targeting rule or a price level targeting rule to minimize a quadratic loss function using the actual projection model of the Bank of Canada (ToTEM). The paper finds that price level targeting dominates inflation targeting, although it can lead to much more volatile inflation depending on the weight a...

  18. Assessment of older driver performance under low level alcohol impairment.

    Science.gov (United States)

    2013-03-01

    This report summarizes the outcomes, to date, of the work undertaken to examine : the effects of low level alcohol impairment, especially for older drivers, based on : on-road driving studies. Some of the questions the project initially sought answer...

  19. Locomotion and Transformation of Underwater Micrometer-Sized Molecular Aggregates under Chemical Stimuli

    Science.gov (United States)

    Toyota, Taro; Banno, Taisuke; Castro, Juan M.; Imai, Masayuki

    2017-10-01

    In this review paper, we introduce the mobility and transformation of micrometer-sized molecular aggregates (i.e., oil droplets, liquid crystalline droplets and tubes, and giant vesicles) in water under chemical stimuli. These molecular aggregates comprising lipophilic and/or amphiphilic molecules have drawn much attention as plausible prebiotic cellular structures and dynamic microreactors related to the origins of life. Here, we highlight recent advances and issues concerning the construction of such systems and discuss the implications of these findings to our understanding of protocellular systems.

  20. Molecular Signature of Cancer at Gene Level or Pathway Level? Case Studies of Colorectal Cancer and Prostate Cancer Microarray Data

    Directory of Open Access Journals (Sweden)

    Jiajia Chen

    2013-01-01

    Full Text Available With recent advances in microarray technology, there has been a flourish in genome-scale identification of molecular signatures for cancer. However, the differentially expressed genes obtained by different laboratories are highly divergent. The present discrepancy at gene level indicates a need for a novel strategy to obtain more robust signatures for cancer. In this paper we hypothesize that (1 the expression signatures of different cancer microarray datasets are more similar at pathway level than at gene level; (2 the comparability of the cancer molecular mechanisms of different individuals is related to their genetic similarities. In support of the hypotheses, we summarized theoretical and experimental evidences, and conducted case studies on colorectal and prostate cancer microarray datasets. Based on the above assumption, we propose that reliable cancer signatures should be investigated in the context of biological pathways, within a cohort of genetically homogeneous population. It is hoped that the hypotheses can guide future research in cancer mechanism and signature discovery.

  1. Determination of cadmium at ultra-trace levels by CPE-molecular fluorescence combined methodology

    Energy Technology Data Exchange (ETDEWEB)

    Talio, Maria Carolina [Instituto de Quimica de San Luis (INQUISAL-CONICET), Chacabuco y Pedernera, 5700 San Luis (Argentina); Luconi, Marta O. [Area de Quimica Analitica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, San Luis (Argentina); Masi, Adriana N. [Area de Bromatologia- Ensayo y Valoracion de Medicamentos, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, San Luis (Argentina); Instituto de Quimica de San Luis (INQUISAL-CONICET), Chacabuco y Pedernera, 5700 San Luis (Argentina); Fernandez, Liliana P., E-mail: lfernand@unsl.edu.ar [Area de Quimica Analitica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, San Luis (Argentina); Instituto de Quimica de San Luis (INQUISAL-CONICET), Chacabuco y Pedernera, 5700 San Luis (Argentina)

    2009-10-15

    A highly sensitive micelle-mediated extraction methodology for the preconcentration and determination of trace levels of cadmium by molecular fluorescence has been developed. Metal was complexed with o-phenanthroline (o-phen) and eosin (eo) at pH 7.6 in buffer Tris medium and quantitatively extracted into a small volume of surfactant-rich phase of PONPE 7.5 after centrifugating. The chemical variables affecting cloud point extraction (CPE) were evaluated and optimized. The RSD for six replicates of cadmium determinations at 0.84 {mu}g L{sup -1} level was 1.17%. The linearity range using the preconcentration system was between 2.79 x 10{sup -3} {mu}g L{sup -1} and 2.81 {mu}g L{sup -1} with a correlation coefficient of 0.99. Under the optimal conditions, it obtained a LOD of 8.38 x 10{sup -4} {mu}g L{sup -1} and LOQ of 2.79 x 10{sup -3} {mu}g L{sup -1}. The method presented good sensitivity and selectivity and was applied to the determination of trace amounts of cadmium in commercially bottled mineral water, tap water and water well samples with satisfactory results. The proposed method is an innovative application of CPE-luminescence to metal analysis comparable in sensitivity and accuracy with atomic spectroscopies.

  2. Understanding unusual thermal transport behavior in soft materials under mechanical strain - A molecular dynamics study

    Science.gov (United States)

    Murad, Sohail; Puri, Ishwar K.

    2015-04-01

    Experiments have shown a dependence of the thermal conductivity of soft polymer materials on shear stress, which is common to several applications, such as film processing, fiber spinning, blow molding, and vacuum forming. Experiments reveal that the conductivity initially decreases with shear, but then increases as additional shear rate is applied. Based on molecular principles, we hypothesize that when molecules are initially placed under tension and extended, they disentangle, which reduces the number of points of interaction and diminishes the heat flux. Further molecular stretching increases this flux because the molecules are now better axially aligned. Molecular dynamics simulations confirm this competition and reproduce the inflection in the flux-strain relationship, which has not been previously explained.

  3. Structural and vibrational dynamics of molecular solids under variable temperature and pressure

    Science.gov (United States)

    Schatschneider, Bohdan Hindulak

    An ultra-high resolution FTIR study (0.01cm-1) coupled with molecular simulations of para-terphenyl (PTP) under variable temperatures and pressures has been conducted in an effort to better understand the molecular dynamics (MD) of organic molecular crystals. PTP's use as an electrooptic material and as a host matrix for single molecular spectroscopy has created significant interest into the systems dynamics under variable conditions. Our high resolution study reveals many structure and dynamics changes in the PTP matrix as a result of changes in temperature and pressure. Further spectroscopic analysis using MD verifies these structural and dynamics alterations. Accurately modeled pressure and temperature phase transitions between the low-temperature low-pressure triclinic phase and the high-pressure high-temperature monoclinic phase of PTP was accomplished by a one-parameter optimization of the torsion potential component of the polymer consistent force field (PCFF) along with incorporation of COMPASS' (Condensed-phase Optimized Molecular Potentials for Atomistic Simulation Studies) non-bond parameters. Initial MD simulations implementing the universal force field COMPASS could not adequately model the experimental crystal structure at 113K, nor could it reproduce the known transition temperature at ambient pressure or yield a well-defined transition pressure at low temperature. Therefore, we needed to create a new potential which was shown to reproduce the solid-solid phase transitions. The previously never simulated pressure induced solid-solid phase transition of PTP at low temperature (20K) and varying pressures (0-1GPa) was modeled. The symmetry based crystal/molecular rearrangement shows a compression and distortion of the unit cell and corresponding angles along with a flattening of the once twisted PTP molecules at high pressures (>0.5GPa). A fourth crystal phase (Phase IV) has been successfully identified through analysis of the individual molecule

  4. Characterization of QTLs for Root Traits of Wheat Grown under Different Nitrogen and Phosphorus Supply Levels

    Science.gov (United States)

    Ren, Yongzhe; Qian, Yingying; Xu, Yanhua; Zou, ChunQin; Liu, Dongcheng; Zhao, Xueqiang; Zhang, Aimin; Tong, Yiping

    2017-01-01

    Root is important in acquiring nutrients from soils. Developing marker-assisted selection for wheat root traits can help wheat breeders to select roots desirable for efficient acquisition of nutrients. A recombinant inbred line (RIL) population derived from wheat varieties Xiaoyan 54 and Jing 411 was used to detect QTLs for maximum root length and root dry weight (RDW) under control, low nitrogen and low phosphorus conditions in hydrophobic culture (HC). We totally detected 17 QTLs for the investigated root traits located at 13 loci on 11 chromosomes. These loci differentially expressed under different nutrient supplying levels. The RILs simultaneously harboring positive alleles or negative alleles of the most significant three QTLs for RDW, qRDW.CK-2A, qRDW.CK-2D, and qRDW.CK-3B, were selected for soil column culture (SC) trial to verify the effects of these QTLs under soil conditions. The RILs pyramiding the positive alleles not only had significantly higher shoot dry weight, RDW, nitrogen and phosphorus uptake in all the three treatments of the HC trial, but also had significantly higher RDW distribution in both the top- and sub-soils in the SC trial than those pyramiding the negative alleles. These results suggested that QTL analysis based on hydroponic culture can provide useful information for molecular design of wheat with large and deep root system. PMID:29312372

  5. Essential concepts and underlying theories from physics, chemistry, and mathematics for "biochemistry and molecular biology" majors.

    Science.gov (United States)

    Wright, Ann; Provost, Joseph; Roecklein-Canfield, Jennifer A; Bell, Ellis

    2013-01-01

    Over the past two years, through an NSF RCN UBE grant, the ASBMB has held regional workshops for faculty members from around the country. The workshops have focused on developing lists of Core Principles or Foundational Concepts in Biochemistry and Molecular Biology, a list of foundational skills, and foundational concepts from Physics, Chemistry, and Mathematics that all Biochemistry or Molecular Biology majors must understand to complete their major coursework. The allied fields working group created a survey to validate foundational concepts from Physics, Chemistry, and Mathematics identified from participant feedback at various workshops. One-hundred twenty participants responded to the survey and 68% of the respondents answered yes to the question: "We have identified the following as the core concepts and underlying theories from Physics, Chemistry, and Mathematics that Biochemistry majors or Molecular Biology majors need to understand after they complete their major courses: 1) mechanical concepts from Physics, 2) energy and thermodynamic concepts from Physics, 3) critical concepts of structure from chemistry, 4) critical concepts of reactions from Chemistry, and 5) essential Mathematics. In your opinion, is the above list complete?" Respondents also delineated subcategories they felt should be included in these broad categories. From the results of the survey and this analysis the allied fields working group constructed a consensus list of allied fields concepts, which will help inform Biochemistry and Molecular Biology educators when considering the ASBMB recommended curriculum for Biochemistry or Molecular Biology majors and in the development of appropriate assessment tools to gauge student understanding of how these concepts relate to biochemistry and molecular biology. © 2013 by The International Union of Biochemistry and Molecular Biology.

  6. Kalanchoe crop development under different levels of irrigation

    Directory of Open Access Journals (Sweden)

    Fátima Cibele Soares

    Full Text Available ABSTRACT Despite its importance in the floriculture sector, irrigation management of kalanchoe is characterized by empiricism, being necessary further studies on the use of water by this crop. Thus, the objective of this study is to analyze the several effects of irrigation levels on the growth of kalanchoe crop conducted in greenhouse in the municipality of Alegrete, state of Rio Grande do Sul. The experiment was conducted in a 7 x 15 m protected environment. The experimental design was completely randomized, with four treatments (irrigation levels corresponding to 40, 60, 80 and 100% of the pot water retention capacity - PC and four repetitions, totaling sixteen plots. The crop cycle was 224 days after transplanting and the applied average depths were: 451.82; 367.38; 282.94; 198.51 mm for treatments: 100; 80; 60 and 40% of PC, respectively. Canopy area and number of leaves per plant were evaluated over the crop cycle. In the end of the cycle, the canopy diameter, number of inflorescences per plant and the number of flowers per plant were evaluated. No significant differences were found only to the canopy area, by the F test. Irrigation water depths between 40 and 70% of the pot capacity were more appropriate for the crop growth in the study region. The cultivar presented the best development at irrigation levels below the maximum vessel water retention capacity, that is, it is resistant to drought.

  7. Foundational concepts and underlying theories for majors in "biochemistry and molecular biology".

    Science.gov (United States)

    Tansey, John T; Baird, Teaster; Cox, Michael M; Fox, Kristin M; Knight, Jennifer; Sears, Duane; Bell, Ellis

    2013-01-01

    Over the past two years, through an NSF RCN UBE grant, the ASBMB has held regional workshops for faculty members and science educators from around the country that focused on identifying: 1) core principles of biochemistry and molecular biology, 2) essential concepts and underlying theories from physics, chemistry, and mathematics, and 3) foundational skills that undergraduate majors in biochemistry and molecular biology must understand to complete their major coursework. Using information gained from these workshops, as well as from the ASBMB accreditation working group and the NSF Vision and Change report, the Core Concepts working group has developed a consensus list of learning outcomes and objectives based on five foundational concepts (evolution, matter and energy transformation, homeostasis, information flow, and macromolecular structure and function) that represent the expected conceptual knowledge base for undergraduate degrees in biochemistry and molecular biology. This consensus will aid biochemistry and molecular biology educators in the development of assessment tools for the new ASBMB recommended curriculum. © 2013 by The International Union of Biochemistry and Molecular Biology.

  8. Exploring the molecular mechanisms underlying the potentiation of exogenous growth hormone on alcohol-induced fatty liver diseases in mice

    Directory of Open Access Journals (Sweden)

    Tian Ya-ping

    2010-11-01

    Full Text Available Abstract Background Growth hormone (GH is an essential regulator of intrahepatic lipid metabolism by activating multiple complex hepatic signaling cascades. Here, we examined whether chronic exogenous GH administration (via gene therapy could ameliorate liver steatosis in animal models of alcoholic fatty liver disease (AFLD and explored the underlying molecular mechanisms. Methods Male C57BL/6J mice were fed either an alcohol or a control liquid diet with or without GH therapy for 6 weeks. Biochemical parameters, liver histology, oxidative stress markers, and serum high molecular weight (HMW adiponectin were measured. Quantitative real-time PCR and western blotting were also conducted to determine the underlying molecular mechanism. Results Serum HMW adiponectin levels were significantly higher in the GH1-treated control group than in the control group (3.98 ± 0.71 μg/mL vs. 3.07 ± 0.55 μg/mL; P P P P P Conclusions GH therapy had positive effects on AFLD and may offer a promising approach to prevent or treat AFLD. These beneficial effects of GH on AFLD were achieved through the activation of the hepatic adiponectin-SIRT1-AMPK and PPARα-AMPK signaling systems.

  9. Molecular mechanism of catalase activity change under sodium dodecyl sulfate-induced oxidative stress in the mouse primary hepatocytes.

    Science.gov (United States)

    Wang, Jing; Wang, Jiaxi; Xu, Chi; Liu, Rutao; Chen, Yadong

    2016-04-15

    Sodium dodecyl sulfate (SDS) contributes to adverse effects of organisms probably because of its ability to induce oxidative stress via changing the activity of antioxidant enzyme catalase (CAT). But the underlying molecular mechanisms still remain unclear. This study characterized the harmful effects of SDS-induced oxidative stress on the mouse primary hepatocytes as well as the structure and function of CAT molecule and investigated the underlying molecular mechanism. After 12h SDS (0.1μM to 0.2mM) exposure, no significant change was observed in CAT activity of the hepatocytes. After 0.5 and 0.8mM SDS exposure, the state of oxidative stress stimulated CAT production in the hepatocytes. The inhibition of CAT activity induced by directly interacting with SDS was unable to catch the synthesis of CAT and therefore resulted in the increased activity and elevated ROS level. Further molecular experiments showed that SDS prefers to bind to the interface with no direct effect on the active site and the structure of heme groups of CAT molecule. When the sites in the interface is saturated, SDS interacts with VAL 73, HIS 74, ASN 147 and PHE 152, the key residues of the enzyme activity, and leads to the decrease of CAT activity. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Effects of molecular structural variants on serum Krebs von den Lungen-6 levels in sarcoidosis

    Directory of Open Access Journals (Sweden)

    Shigemura Masahiko

    2012-07-01

    Full Text Available Abstract Background Serum Krebs von den Lungen-6 (KL-6, which is classified as human mucin-1 (MUC1, is used as a marker of sarcoidosis and other interstitial lung diseases. However, there remain some limitations due to a lack of information on the factors contributing to increased levels of serum KL-6. This study was designed to investigate the factors contributing to increased levels of serum KL-6 by molecular analysis. Methods Western blot analysis using anti-KL-6 antibody was performed simultaneously on the bronchoalveolar lavage fluid (BALF and serum obtained from 128 subjects with sarcoidosis. Results KL-6/MUC1 in BALF showed three bands and five band patterns. These band patterns were associated with the MUC1 genotype and the KL-6 levels. KL-6/MUC1 band patterns in serum were dependent on molecular size class in BALF. Significantly increased levels of serum KL-6, serum/BALF KL-6 ratio and serum soluble interleukin 2 receptor were observed in the subjects with influx of high molecular size KL-6/MUC1 from the alveoli to blood circulation. The multivariate linear regression analysis involving potentially relevant variables such as age, gender, smoking status, lung parenchymal involvement based on radiographical stage and molecular size of KL-6/MUC1 in serum showed that the molecular size of KL-6/MUC1 in serum was significant independent determinant of serum KL-6 levels. Conclusions The molecular structural variants of KL-6/MUC1 and its leakage behavior affect serum levels of KL-6 in sarcoidosis. This information may assist in the interpretation of serum KL-6 levels in sarcoidosis.

  11. Recent progress in transition-metal-catalyzed reduction of molecular dinitrogen under ambient reaction conditions.

    Science.gov (United States)

    Nishibayashi, Yoshiaki

    2015-10-05

    This paper describes our recent progress in catalytic nitrogen fixation by using transition-metal-dinitrogen complexes as catalysts. Two reaction systems for the catalytic transformation of molecular dinitrogen into ammonia and its equivalent such as silylamine under ambient reaction conditions have been achieved by the molybdenum-, iron-, and cobalt-dinitrogen complexes as catalysts. Many new findings presented here may provide new access to the development of economical nitrogen fixation in place of the Haber-Bosch process.

  12. Comparative Phenotypical and Molecular Analyses of Arabidopsis Grown under Fluorescent and LED Light

    OpenAIRE

    Seiler, Franka; Soll, J?rgen; B?lter, Bettina

    2017-01-01

    Comparative analyses of phenotypic and molecular traits of Arabidopsis thaliana grown under standardised conditions is still a challenge using climatic devices supplied with common light sources. These are in most cases fluorescent lights, which have several disadvantages such as heat production at higher light intensities, an invariable spectral output, and relatively rapid “ageing”. This results in non-desired variations of growth conditions and lowers the comparability of data acquired ove...

  13. Correlation of molecular resistance mechanisms and phenotypic resistance levels in streptomycin-resistant Mycobacterium tuberculosis.

    OpenAIRE

    Meier, A; Sander, P; Schaper, K J; Scholz, M; Böttger, E C

    1996-01-01

    Quantitative susceptibility testing of clinical isolates of streptomycin-resistant Mycobacterium tuberculosis demonstrated that there is a close correlation between the molecular resistance mechanism and the in vitro activity of streptomycin: mutations in rpsL were mainly associated with high-level resistance, mutations in rrs were associated with an intermediate level of resistance, and streptomycin-resistant isolates with wild-type rpsL and rrs exhibited a low-level resistance phenotype. In...

  14. Sea level rise under the Shared Socioeconomic Pathways (SSPs)

    Science.gov (United States)

    Schleussner, C. F.; Nauels, A.; Rogelj, J.; Mengel, M.; Meinshausen, M.

    2017-12-01

    In order to assess future sea level rise and its impacts, we need to study climate change pathways combined with different scenarios of socioeconomic development. Here, we present Sea Level Rise (SLR) projections for the Shared Socioeconomic Pathway (SSP) storylines and different year-2100 radiative Forcing Targets (FTs). Future SLR is estimated with a comprehensive SLR emulator that accounts for latest research on additional Antarctic rapid discharge dynamics from hydrofracturing and ice cliff instability. Across all baseline scenario realizations (no dedicated climate mitigation), we find 2100 median SLR relative to 1986-2005 of 102 cm (likely range: 77 to 135 cm) for SSP1, 118 cm (90 to 151 cm) for SSP2, 118 cm (91 to 149 cm) for SSP3, 107 cm (81 to 137 cm) for SSP4, and 144 cm (112 to 184 cm) for SSP5. The 2100 sea level responses for combined SSP-FT scenarios is dominated by the mitigation targets and yield median estimates of 68 cm (56 to 87 cm) for FT 2.6 Wm-2, 76 cm (61 to 107 cm) for FT 3.4 Wm-2, 90 cm (68 to 120 cm) for FT 4.5 Wm-2, and 105 cm (79 to 136 cm) for FT 6.0 Wm-2. Average 2081-2100 annual rates of SLR are 6 mm/yr and 19 mm/yr for the FT 2.6 Wm-2 and the baseline scenarios, respectively. Our model setup allows linking scenario-specific emission and socioeconomic indicators to projected SLR. For limiting median 2100 SSP SLR projections to below 80 cm, we find that 2050 cumulative CO2 emissions since pre-industrial should not exceed around 860 GtC, with the global coal phase-out nearly completed. For SSP mitigation scenarios, the median 2050 carbon price of 90 US$2005 tCO2-1 would correspond to a median 2100 SLR of around 80 cm. Our results confirm that rapid and early emission reductions are essential for limiting 2100 SLR.

  15. GROWTH AND PRODUCTIVITY OF SUGARCANE VARIETIES UNDER VARIOUS IRRIGATION LEVELS

    Directory of Open Access Journals (Sweden)

    CICERO TEIXEIRA SILVA COSTA

    2016-01-01

    Full Text Available This study evaluated the growth and agro - industrial productivity of sugarcane varieties subjected to different irrigation levels in the county of Penápolis - São Paulo, Brazil. The experimental design was a randomized block with a factorial arrangement of 2 × 7 (two cultivars of sugarcane: RB965902 and RB855453, at seven irrigation levels: L0 = 0%, L1 = 25%, L2 = 50%, L3 = 75%, L4 = 100%, L5 = 125%, and L6 = 150% of crop evapotranspiration - ETc with four replicates. The irrigation system was a subsurface drip at a flow rate of 1.4 L h - 1 . The variables evaluated were tillering, culm length, leaf area index (LAI, dry matter, and industrial productivity. The maximum number of plants per linear meter was 30 for variety RB965902 at 100% ETc, and 29 for variety RB855453 at 125% of ETc. Maximum tillering occurred at 120 and 150 days after planting (DAP for RB965902 and RB855453, respectively. The maximum LAI of BR965902 was 9.57 at 210 DAP and 9.81 at 201 DAP for the RB855453 variety. The RB855453 variety produced an average of 178.93 t ha - 1 with irrigation and 164.81 t ha - 1 without, while the variety RB965902 produced 164.08 t ha - 1 and 154.61 t ha - 1 with and without irrigation, respectively. At harvest, the total recoverable sugars (TRS were 129.62 kg t - 1 for RB965902 and 131.63 kg t - 1 for RB855443. The RB855453 variety produced on average 14.19 t ha - 1 more than the RB965902 variety.

  16. A Multi-Step and Multi-Level Approach for Computer Aided Molecular Design

    DEFF Research Database (Denmark)

    Harper, Peter Mathias; Gani, Rafiqul

    2001-01-01

    A general multi-step approach for setting up, solving and solution analysis of computer aided molecular design (CAMD) problems is presented. The approach differs from previous work within the field of CAMD since it also addresses the need for a computer aided problem formulation and result analysis....... The problem formulation step incorporates a knowledge base for the identification and setup of the design criteria. Candidate compounds are identified using a multi-level generate and test CAMD solution algorithm capable of designing molecules having a high level of molecular detail. A post solution step...

  17. Evaluation of the molecular level visualisation approach for teaching and learning chemistry in Thailand

    Science.gov (United States)

    Phenglengdi, Butsari

    This research evaluates the use of a molecular level visualisation approach in Thai secondary schools. The goal is to obtain insights about the usefulness of this approach, and to examine possible improvements in how the approach might be applied in the future. The methodology used for this research used both qualitative and quantitative approaches. Data were collected in the form of pre- and post-intervention multiple choice questions, open-ended-questions, drawing exercises, one-to-one interviews and video recordings of class activity. The research was conducted in two phases, involving a total of 261 students from the 11th Grade in Thailand. The use of VisChem animations in three studies was evaluated in Phase I. Study 1 was a pilot study exploring the benefits of incorporating VisChem animations to portray the molecular level. Study 2 compared test results between students exposed to these animations of molecular level events, and those not. Finally, in Study 3, test results were gathered from different types of schools (a rural school, a city school, and a university school). The results showed that students (and teachers) had misconceptions at the molecular level, and VisChem animations could help students understand chemistry concepts at the molecular level across all three types of schools. While the animation treatment group had a better score on the topic of states of water, the non-animation treatment group had a better score on the topic of dissolving sodium chloride in water than the animation group. The molecular level visualisation approach as a learning design was evaluated in Phase II. This approach involved a combination of VisChem animations, pictures, and diagrams together with the seven-step VisChem learning design. The study involved three classes of students, each with a different treatment, described as Class A - Traditional approach; Class B - VisChem animations with traditional approach; and Class C - Molecular level visualisation approach

  18. Elevated levels of high-molecular-weight adiponectin in type 1 diabetes

    DEFF Research Database (Denmark)

    Leth, H.; Andersen, K.K.; Frystyk, J.

    2008-01-01

    BACKGROUND: Several studies have shown that type 1 diabetic patients have elevated total levels of the adipocyte-derived adipocytokine adiponectin. However, adiponectin circulates in three different subforms, and the high-molecular-weight (HMW) subform is believed to be the primary biologically...... active form. The effects of the medium-molecular-weight (MMW) subform and the low-molecular-weight (LMW) subform are still unresolved. PURPOSE: The objective of the study was to investigate the distribution of the three molecular subforms of adiponectin in well-characterized groups of type 1 diabetics...... with varying degrees of nephropathy as well as in healthy control subjects. STUDY POPULATION: Two hundred seven individuals were included: 58 type 1 diabetics with normoalbuminuria, 46 with microalbuminuria, 46 with macroalbuminuria, and 57 matched controls. METHODS: The HMW, MMW, and LMW subforms were...

  19. Cognitive neuroepigenetics: the next evolution in our understanding of the molecular mechanisms underlying learning and memory?

    Science.gov (United States)

    Marshall, Paul; Bredy, Timothy W.

    2016-07-01

    A complete understanding of the fundamental mechanisms of learning and memory continues to elude neuroscientists. Although many important discoveries have been made, the question of how memories are encoded and maintained at the molecular level remains. So far, this issue has been framed within the context of one of the most dominant concepts in molecular biology, the central dogma, and the result has been a protein-centric view of memory. Here, we discuss the evidence supporting a role for neuroepigenetic mechanisms, which constitute dynamic and reversible, state-dependent modifications at all levels of control over cellular function, and their role in learning and memory. This neuroepigenetic view suggests that DNA, RNA and protein each influence one another to produce a holistic cellular state that contributes to the formation and maintenance of memory, and predicts a parallel and distributed system for the consolidation, storage and retrieval of the engram.

  20. Molecular Alteration of Marine Dissolved Organic Matter under Experimental Hydrothermal Conditions

    Science.gov (United States)

    Hawkes, J. A.; Hansen, C. T.; Goldhammer, T.; Bach, W.; Dittmar, T.

    2016-02-01

    Marine dissolved organic matter (DOM) is a large (660 Pg) pool of reduced carbon that is subject to thermal alteration in hydrothermal systems and sedimentary basins. In natural hydrothermal systems, DOM is almost completely removed, but the mechanism, kinetics and temperature dependence of this removal have not been studied to date. We investigated molecular-level changes to DOM that was solid-phase extracted (SPE-DOM) from the deep ocean of the North Pacific Ocean. This complex molecular mixture was experimentally exposed to temperatures between 100-380 °C over the course of two weeks in artificial seawater, and was then characterized on a molecular level via ultrahigh-resolution mass spectrometry (FTICRMS & Orbitrap). Almost 93% of SPE-DOM was removed by the treatment at 380 °C, and this removal was accompanied by a consistent pattern of SPE-DOM alteration across the temperatures studied, which can likely be extrapolated down to temperatures around 68 °C. Higher molecular weight and more oxygen rich compounds were preferentially degraded, suggesting that decarboxylation and dehydration of carboxylic acid and alcohol groups are the most rapid degradation mechanisms. Nitrogen containing compounds followed the same overall trends as those containing just C, H and O up to 300 °C. Above this temperature, the most highly degraded samples contained very little of the original character of marine DOM, instead being mainly composed of very low intensity N- and S- containing molecules with a high H:C ratio (>1.5). Our experiments were conducted without a sedimentary or mineral phase, and demonstrate that profound molecular alteration and almost complete removal of marine SPE-DOM requires nothing more than heating in a seawater matrix.

  1. Heat impact caused molecular level changes in solid and dissolved soil organic matter

    Science.gov (United States)

    Hofmann, Diana; Steffen, Bernhard; Eckhardt, Kai-Uwe; Leinweber, Peter

    2015-04-01

    resolution (used 400.000 at m/z 400 Da) and mass accuracy (≤ 1 ppm), simultaneously providing molecular level details of thousands of compounds. The characteristics and differences of the FTICR-MS spectra with as many as ten or more peaks at each nominal mass are discussed: heated samples showed considerable higher intensities of even numbered peaks. An in-house developed, automated post processing was used for further exploitation of the data with the aim of an unambiguous assignment of as many peaks as possible. Obtained mass lists were transformed for sorting and preparation/ interpretation of graphics like Kendrick and van Krevelen plots. The heat-treated solid samples show decreasing C/N ratios and the formation cyclic and N-heterocyclic compounds in good agreement among the various methods (Py-FIMS and C- and N-XANES). Detailed insight into the hot-water extracts by FTICR-MS showed clear qualitative as well as quantitative changes in the number and the intensity of nitrogen and nitrogen + sulfur containing compounds, respectively, which generally became enriched under soil heating. This demonstrates for the first time, that not only the bulk SOM is affected in structure by heat impact but also the more mobile DOM. We assume, that heat impact volatilizes and oxidizes parts of the organic substances is as expected but another part of the substances incorporates (further) nitrogen atom(s) similar to the generation of new compounds under the conditions of plasma etching in nitrogen atmosphere. This would explain to some extent, why soils are e.g. after fire clearing of vegetation are highly fertile for a short period (better plant acceptable compounds) but become more infertile in the long run, especially under tropical conditions with frequently heavy rain that would lead to an increased leaching of compounds with higher polarity.

  2. Cerebrospinal fluid tau levels are a marker for molecular subtype in sporadic Creutzfeldt-Jakob disease.

    Science.gov (United States)

    Karch, André; Hermann, Peter; Ponto, Claudia; Schmitz, Matthias; Arora, Amandeep; Zafar, Saima; Llorens, Franc; Müller-Heine, Annika; Zerr, Inga

    2015-05-01

    The molecular subtype of sporadic Creutzfeldt-Jakob disease (sCJD) is an important prognostic marker for patient survival. However, subtype determination is not possible during lifetime. Because the rate of disease progression is associated with the molecular subtype, this study aimed at investigating if total tau, a marker of neuronal death, allows premortem diagnosis of molecular subtype when codon 129 genotype is known. Two hundred ninety-six sCJD patients were tested for their cerebrospinal fluid total tau level at the time of diagnosis and were investigated for their sCJD subtype postmortem. There was a significant association between tau levels and the prion protein type in patients with codon 129 MM (p disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. A Multi-step and Multi-level approach for Computer Aided Molecular Design

    DEFF Research Database (Denmark)

    A general multi-step approach for setting up, solving and solution analysis of computer aided molecular design (CAMD) problems is presented. The approach differs from previous work within the field of CAMD since it also addresses the need for a computer aided problem formulation and result analysis....... The problem formulation step incorporates a knowledge base for the identification and setup of the design criteria. Candidate compounds are identified using a multi-level generate and test CAMD solution algorithm capable of designing molecules having a high level of molecular detail. A post solution step...... using an Integrated Computer Aided System (ICAS) for result analysis and verification is included in the methodology. Keywords: CAMD, separation processes, knowledge base, molecular design, solvent selection, substitution, group contribution, property prediction, ICAS Introduction The use of Computer...

  4. Non-Newtonian behavior and molecular structure of Cooee bitumen under shear flow

    DEFF Research Database (Denmark)

    Lemarchand, Claire; Bailey, Nicholas; Daivis, Peter

    2015-01-01

    The rheology and molecular structure of a model bitumen (Cooee bitumen) under shear are investigated in the non-Newtonian regime using non-equilibrium molecular dynamics simulations. The shear viscosity, normal stress differences, and pressure of the bitumen mixture are computed at different shear...... of the viscosity with temperature at different shear rates is also related to the size and relative composition of the nanoaggregates. The slight anisotropy of the whole sample due to the nanoaggregates is considered and quantified. Finally, the position of bitumen mixtures in the broad literature of complex...... rates and different temperatures. The model bitumen is shown to be a shear-thinning fluid at all temperatures. In addition, the Cooee model is able to reproduce experimental results showing the formation of nanoaggregates composed of stacks of flat aromatic molecules in bitumen. These nanoaggregates...

  5. Neutral molecular cluster formation of sulfuric acid–dimethylamine observed in real time under atmospheric conditions

    CERN Document Server

    Kürten, Andreas; Simon, Mario; Sipilä, Mikko; Sarnela, Nina; Junninen, Heikki; Adamov, Alexey; Almeida, João; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; Dommen, Josef; Donahue, Neil M; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Hutterli, Manuel; Kangasluoma, Juha; Kirkby, Jasper; Laaksonen, Ari; Lehtipalo, Katrianne; Leiminger, Markus; Makhmutov, Vladimir; Mathot, Serge; Onnela, Antti; Petäjä, Tuukka; Praplan, Arnaud P; Riccobono, Francesco; Rissanen, Matti P; Rondo, Linda; Schobesberger, Siegfried; Seinfeld, John H; Steiner, Gerhard; Tomé, António; Tröstl, Jasmin; Winkler, Paul M; Williamson, Christina; Wimmer, Daniela; Ye, Penglin; Baltensperger, Urs; Carslaw, Kenneth S; Kulmala, Markku; Worsnop, Douglas R; Curtius, Joachim

    2014-01-01

    For atmospheric sulfuric acid (SA) concentrations the presence of dimethylamine (DMA) at mixing ratios of several parts per trillion by volume can explain observed boundary layer new particle formation rates. However, the concentration and molecular composition of the neutral (uncharged) clusters have not been reported so far due to the lack of suitable instrumentation. Here we report on experiments from the Cosmics Leaving Outdoor Droplets chamber at the European Organization for Nuclear Research revealing the formation of neutral particles containing up to 14 SA and 16 DMA molecules, corresponding to a mobility diameter of about 2 nm, under atmospherically relevant conditions. These measurements bridge the gap between the molecular and particle perspectives of nucleation, revealing the fundamental processes involved in particle formation and growth. The neutral clusters are found to form at or close to the kinetic limit where particle formation is limited only by the collision rate of SA molecules. Even tho...

  6. Molecular and Microbial Mechanisms Increasing Soil C Storage Under Future Rates of Anthropogenic N Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zak, Donald R.

    2017-11-17

    A growing body of evidence reveals that anthropogenic N deposition can reduce the microbial decay of plant detritus and increase soil C storage across a wide range of terrestrial ecosystems. This aspect of global change has the potential to constrain the accumulation of anthropogenic CO2 in the Earth’s atmosphere, and hence slow the pace of climate warming. The molecular and microbial mechanisms underlying this biogeochemical response are not understood, and they are not a component of any coupled climate-biogeochemical model estimating ecosystem C storage, and hence, the future climate of an N-enriched Earth. Here, we report the use of genomic-enabled approaches to identify the molecular underpinnings of the microbial mechanisms leading to greater soil C storage in response to anthropogenic N deposition, thereby enabling us to better anticipate changes in soil C storage.

  7. Application and interpretation of biomarkers in ecotoxicology - from molecular to individual level responses

    OpenAIRE

    Furuhagen, Sara

    2015-01-01

    The use of biomarkers is considered a promising alternative, or complement, to traditional ecotoxicological assays. Toxic effects are often initially manifested at the molecular or biochemical level, biomarkers are therefore used as sensitive indicators of toxic exposure. Ideally, biomarkers would also indicate reduced fitness and possible later effects at the individual or population levels. However, implementing biomarkers in ecotoxicology is challenging and few biomarkers have an establish...

  8. Nanomaterials under extreme environments: A study of structural and dynamic properties using reactive molecular dynamics simulations

    Science.gov (United States)

    Shekhar, Adarsh

    Nanotechnology is becoming increasingly important with the continuing advances in experimental techniques. As researchers around the world are trying to expand the current understanding of the behavior of materials at the atomistic scale, the limited resolution of equipment, both in terms of time and space, act as roadblocks to a comprehensive study. Numerical methods, in general and molecular dynamics, in particular act as able compliment to the experiments in our quest for understanding material behavior. In this research work, large scale molecular dynamics simulations to gain insight into the mechano-chemical behavior under extreme conditions of a variety of systems with many real world applications. The body of this work is divided into three parts, each covering a particular system: 1) Aggregates of aluminum nanoparticles are good solid fuel due to high flame propagation rates. Multi-million atom molecular dynamics simulations reveal the mechanism underlying higher reaction rate in a chain of aluminum nanoparticles as compared to an isolated nanoparticle. This is due to the penetration of hot atoms from reacting nanoparticles to an adjacent, unreacted nanoparticle, which brings in external heat and initiates exothermic oxidation reactions. 2) Cavitation bubbles readily occur in fluids subjected to rapid changes in pressure. We use billion-atom reactive molecular dynamics simulations on a 163,840-processor BlueGene/P supercomputer to investigate chemical and mechanical damages caused by shock-induced collapse of nanobubbles in water near amorphous silica. Collapse of an empty nanobubble generates high-speed nanojet, resulting in the formation of a pit on the surface. The pit contains a large number of silanol groups and its volume is found to be directly proportional to the volume of the nanobubble. The gas-filled bubbles undergo partial collapse and consequently the damage on the silica surface is mitigated. 3) The structure and dynamics of water confined in

  9. Mapping Hydrophobicity on the Protein Molecular Surface at Atom-Level Resolution

    Science.gov (United States)

    Nicolau Jr., Dan V.; Paszek, Ewa; Fulga, Florin; Nicolau, Dan V.

    2014-01-01

    A precise representation of the spatial distribution of hydrophobicity, hydrophilicity and charges on the molecular surface of proteins is critical for the understanding of the interaction with small molecules and larger systems. The representation of hydrophobicity is rarely done at atom-level, as this property is generally assigned to residues. A new methodology for the derivation of atomic hydrophobicity from any amino acid-based hydrophobicity scale was used to derive 8 sets of atomic hydrophobicities, one of which was used to generate the molecular surfaces for 35 proteins with convex structures, 5 of which, i.e., lysozyme, ribonuclease, hemoglobin, albumin and IgG, have been analyzed in more detail. Sets of the molecular surfaces of the model proteins have been constructed using spherical probes with increasingly large radii, from 1.4 to 20 Å, followed by the quantification of (i) the surface hydrophobicity; (ii) their respective molecular surface areas, i.e., total, hydrophilic and hydrophobic area; and (iii) their relative densities, i.e., divided by the total molecular area; or specific densities, i.e., divided by property-specific area. Compared with the amino acid-based formalism, the atom-level description reveals molecular surfaces which (i) present an approximately two times more hydrophilic areas; with (ii) less extended, but between 2 to 5 times more intense hydrophilic patches; and (iii) 3 to 20 times more extended hydrophobic areas. The hydrophobic areas are also approximately 2 times more hydrophobicity-intense. This, more pronounced “leopard skin”-like, design of the protein molecular surface has been confirmed by comparing the results for a restricted set of homologous proteins, i.e., hemoglobins diverging by only one residue (Trp37). These results suggest that the representation of hydrophobicity on the protein molecular surfaces at atom-level resolution, coupled with the probing of the molecular surface at different geometric resolutions

  10. The role of stable α-synuclein oligomers in the molecular events underlying amyloid formation

    DEFF Research Database (Denmark)

    Lorenzen, Nikolai; Nielsen, Søren Bang; Buell, Alexander K.

    2014-01-01

    α-synuclein (αSN), whose aggregation is strongly implicated in the development of Parkinson’s disease (PD). The two types of oligomers are both formed under conditions where amyloid fibril formation is observed but differ in molecular weight by an order of magnitude. Both possess a degree of β......, either as precursors of fibrils or as species involved in the fibril elongation process or instead if they are associated with an aggregation process that is distinct from that generating mature fibrils. Here we describe and characterize in detail two well-defined oligomeric species formed by the protein...

  11. COPRED: prediction of fold, GO molecular function and functional residues at the domain level.

    Science.gov (United States)

    López, Daniel; Pazos, Florencio

    2013-07-15

    Only recently the first resources devoted to the functional annotation of proteins at the domain level started to appear. The next step is to develop specific methodologies for predicting function at the domain level based on these resources, and to implement them in web servers to be used by the community. In this work, we present COPRED, a web server for the concomitant prediction of fold, molecular function and functional sites at the domain level, based on a methodology for domain molecular function prediction and a resource of domain functional annotations previously developed and benchmarked. COPRED can be freely accessed at http://csbg.cnb.csic.es/copred. The interface works in all standard web browsers. WebGL (natively supported by most browsers) is required for the in-line preview and manipulation of protein 3D structures. The website includes a detailed help section and usage examples. pazos@cnb.csic.es.

  12. Changes in permittivity and density of molecular liquids under high pressure.

    Science.gov (United States)

    Kiselev, Vladimir D; Kornilov, Dmitry A; Konovalov, Alexander I

    2014-04-03

    We collected and analyzed the density and permittivity of 57 nonpolar and dipolar molecular liquids at different temperatures (143 sets) and pressures (555 sets). No equation was found that could accurately predict the change to polar liquid permittivity by the change of its density in the range of the pressures and temperatures tested. Consequently, the influence of high hydrostatic pressure and temperature on liquid permittivity may be a more complicated process compared to density changes. The pressure and temperature coefficients of permittivity can be drastically larger than the pressure and temperature coefficients of density, indicating that pressure and particularly temperature significantly affect the structure of molecular liquids. These changes have less influence on the density change but can strongly affect the permittivity change. The clear relationship between the tangent and secant moduli of the permittivity curvatures under pressure for various molecular liquids at different temperatures was obtained, from which one can calculate the Tait equation coefficients from the experimental values of the pressure influence on the permittivity at ambient pressure.

  13. C sub 6 sub 0 fullerene and its molecular complexes under axial and shear deformation

    CERN Document Server

    Spitsina, N G; Bashkin, I V; Meletov, K P

    2002-01-01

    We have studied the pristine C sub 6 sub 0 and its molecular complexes with the organic donors bis(ethylenedithio) tetrathiafulvalene (BEDT-TTF or ET) and tetramethyltetraselenafulvalene (TMTSF) by means of ESR and Raman spectroscopy at high pressure. The important changes in the ESR signal of C sub 6 sub 0 were observed under axial pressure combined with shear deformation. It is shown that the treatment at a anisotropic pressure of 4 GPa results in a reduction in the symmetry of the C sub 6 sub 0 molecule and the formation of radicals. Treatment of the molecular complex of (ET) sub 2 centre dot C sub 6 sub 0 at a pressure of approx 4.5 GPa and a temperature of 150 deg. C leads to the formation of C sub 6 sub 0 dimers. The Raman spectra of the molecular complex C sub 6 sub 0 centre dot TMTSF centre dot 2(CS sub 2) were measured in situ at ambient temperature and pressures up to 9.5 GPa. The pressure behaviour of the Raman peaks reveals singularity at 5.0 +- 0.5 GPa related to the softening and splitting of so...

  14. Neutral molecular cluster formation of sulfuric acid–dimethylamine observed in real time under atmospheric conditions

    Science.gov (United States)

    Kürten, Andreas; Jokinen, Tuija; Simon, Mario; Sipilä, Mikko; Sarnela, Nina; Junninen, Heikki; Adamov, Alexey; Almeida, João; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; Dommen, Josef; Donahue, Neil M.; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C.; Franchin, Alessandro; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Hutterli, Manuel; Kangasluoma, Juha; Kirkby, Jasper; Laaksonen, Ari; Lehtipalo, Katrianne; Leiminger, Markus; Makhmutov, Vladimir; Mathot, Serge; Onnela, Antti; Petäjä, Tuukka; Praplan, Arnaud P.; Riccobono, Francesco; Rissanen, Matti P.; Rondo, Linda; Schobesberger, Siegfried; Seinfeld, John H.; Steiner, Gerhard; Tomé, António; Tröstl, Jasmin; Winkler, Paul M.; Williamson, Christina; Wimmer, Daniela; Ye, Penglin; Baltensperger, Urs; Carslaw, Kenneth S.; Kulmala, Markku; Worsnop, Douglas R.; Curtius, Joachim

    2014-01-01

    For atmospheric sulfuric acid (SA) concentrations the presence of dimethylamine (DMA) at mixing ratios of several parts per trillion by volume can explain observed boundary layer new particle formation rates. However, the concentration and molecular composition of the neutral (uncharged) clusters have not been reported so far due to the lack of suitable instrumentation. Here we report on experiments from the Cosmics Leaving Outdoor Droplets chamber at the European Organization for Nuclear Research revealing the formation of neutral particles containing up to 14 SA and 16 DMA molecules, corresponding to a mobility diameter of about 2 nm, under atmospherically relevant conditions. These measurements bridge the gap between the molecular and particle perspectives of nucleation, revealing the fundamental processes involved in particle formation and growth. The neutral clusters are found to form at or close to the kinetic limit where particle formation is limited only by the collision rate of SA molecules. Even though the neutral particles are stable against evaporation from the SA dimer onward, the formation rates of particles at 1.7-nm size, which contain about 10 SA molecules, are up to 4 orders of magnitude smaller compared with those of the dimer due to coagulation and wall loss of particles before they reach 1.7 nm in diameter. This demonstrates that neither the atmospheric particle formation rate nor its dependence on SA can simply be interpreted in terms of cluster evaporation or the molecular composition of a critical nucleus. PMID:25288761

  15. Comparative Phenotypical and Molecular Analyses of Arabidopsis Grown under Fluorescent and LED Light.

    Science.gov (United States)

    Seiler, Franka; Soll, Jürgen; Bölter, Bettina

    2017-06-13

    Comparative analyses of phenotypic and molecular traits of Arabidopsis thaliana grown under standardised conditions is still a challenge using climatic devices supplied with common light sources. These are in most cases fluorescent lights, which have several disadvantages such as heat production at higher light intensities, an invariable spectral output, and relatively rapid "ageing". This results in non-desired variations of growth conditions and lowers the comparability of data acquired over extended time periods. In this study, we investigated the growth behaviour of Arabidopsis Col0 under different light conditions, applying fluorescent compared to LED lamps, and we conducted physiological as well as gene expression analyses. By changing the spectral composition and/or light intensity of LEDs we can clearly influence the growth behaviour of Arabidopsis and thereby study phenotypic attributes under very specific light conditions that are stable and reproducible, which is not necessarily given for fluorescent lamps. By using LED lights, we can also roughly mimic the sun light emission spectrum, enabling us to study plant growth in a more natural-like light set-up. We observed distinct growth behaviour under the different light regimes which was reflected by physiological properties of the plants. In conclusion, LEDs provide variable emission spectra for studying plant growth under defined, stable light conditions.

  16. Comparative Phenotypical and Molecular Analyses of Arabidopsis Grown under Fluorescent and LED Light

    Directory of Open Access Journals (Sweden)

    Franka Seiler

    2017-06-01

    Full Text Available Comparative analyses of phenotypic and molecular traits of Arabidopsis thaliana grown under standardised conditions is still a challenge using climatic devices supplied with common light sources. These are in most cases fluorescent lights, which have several disadvantages such as heat production at higher light intensities, an invariable spectral output, and relatively rapid “ageing”. This results in non-desired variations of growth conditions and lowers the comparability of data acquired over extended time periods. In this study, we investigated the growth behaviour of Arabidopsis Col0 under different light conditions, applying fluorescent compared to LED lamps, and we conducted physiological as well as gene expression analyses. By changing the spectral composition and/or light intensity of LEDs we can clearly influence the growth behaviour of Arabidopsis and thereby study phenotypic attributes under very specific light conditions that are stable and reproducible, which is not necessarily given for fluorescent lamps. By using LED lights, we can also roughly mimic the sun light emission spectrum, enabling us to study plant growth in a more natural-like light set-up. We observed distinct growth behaviour under the different light regimes which was reflected by physiological properties of the plants. In conclusion, LEDs provide variable emission spectra for studying plant growth under defined, stable light conditions.

  17. Skin transcriptome reveals the intrinsic molecular mechanisms underlying hair follicle cycling in Cashmere goats under natural and shortened photoperiod conditions.

    Science.gov (United States)

    Yang, Min; Song, Shen; Dong, Kunzhe; Chen, XiaoFei; Liu, Xuexue; Rouzi, Marhaba; Zhao, Qianjun; He, Xiaohong; Pu, Yabin; Guan, Weijun; Ma, Yuehui; Jiang, Lin

    2017-10-18

    The growth of cashmere exhibits a seasonal pattern arising from photoperiod change. However, the underlying molecular mechanism remains unclear. We profiled the skin transcriptome of six goats at seven time points during hair follicle cycling via RNA-seq. The six goats comprised three goats exposed to a natural photoperiod and three exposed to a shortened photoperiod. During hair cycle transition, 1713 genes showed differential expression, and 332 genes showed a pattern of periodic expression. Moreover, a short photoperiod induced the hair follicle to enter anagen early, and 246 genes overlapped with the periodic genes. Among these key genes, cold-shock domain containing C2 (CSDC2) was highly expressed in the epidermis and dermis of Cashmere goat skin, although its function in hair-follicle development remains unknown. CSDC2 silencing in mouse fibroblasts resulted in the decreased mRNA expression of two key hair-follicle factors, leading to reduced cell numbers and a lower cell density. Cashmere growth or molting might be controlled by a set of periodic regulatory genes. The appropriate management of short light exposure can induce hair follicles to enter full anagen early through the activation of these regulators. The CSDC2 gene is a potentially important transcription factor in the hair growth cycle.

  18. Cadmium toxicity studies under long term-low level exposure (LLE) conditions. I

    International Nuclear Information System (INIS)

    Sabbioni, E.; Marafante, E.; Amantini, L.; Ubertalli, L.; Pietra, R.

    1978-01-01

    A long term-low level exposure (LLE) experiment was conducted on rats to determine the metabolic patterns for realistic dietary levels of cadmium. Male rats fed with 61 ppb of cadmium ad libitum, 50 labelled with 109 Cd radiotracer as cadmium chloride via drinking mineral water and 11 unlabelled via food for 2 years. The diet was characterized in its metal content by neutron activation analysis to obtain the total dietary intake of different elements. The kidney was found to be the tissue with the major concentration of cadmium which accumulated continuously during the experiment. The variation of the accumulation pattern of Cd concentration in the liver and intestine indicated an initial rapid increase of Cd during the first 100 days. After this period an apparent equilibrium was attained in both these tissues until the end of the study. The intracellular distribution of cadmium in kidneys, liver, intestine and pancreas were similar, the cytosol fractions containing about 80% of the cellular cadmium. Dialysis experiments indicated that significant amounts of cadmium were able to be associated with cellular organelles, the mitochondria representing the most important organelle capable of binding cadmium. The cytoplasmatic Cd-profiles obtained at various stages of the experiment showed that the metal was only bound to a low-molecular-weight component, cadmium-binding protein (CdBP), which represents the specific cellular-binding component for cadmium under the long term-low level exposure (LLE) conditions. No significant variations in the concentrations of the elements in different organs were observed in animals supplemented with 109 Cd in respect to 109 Cd untreated controls. (Auth.)

  19. Pseudomonas viridiflava, a multi host plant pathogen with significant genetic variation at the molecular level.

    Directory of Open Access Journals (Sweden)

    Panagiotis F Sarris

    Full Text Available The pectinolytic species Pseudomonas viridiflava has a wide host range among plants, causing foliar and stem necrotic lesions and basal stem and root rots. However, little is known about the molecular evolution of this species. In this study we investigated the intraspecies genetic variation of P. viridiflava amongst local (Cretan, as well as international isolates of the pathogen. The genetic and phenotypic variability were investigated by molecular fingerprinting (rep-PCR and partial sequencing of three housekeeping genes (gyrB, rpoD and rpoB, and by biochemical and pathogenicity profiling. The biochemical tests and pathogenicity profiling did not reveal any variability among the isolates studied. However, the molecular fingerprinting patterns and housekeeping gene sequences clearly differentiated them. In a broader phylogenetic comparison of housekeeping gene sequences deposited in GenBank, significant genetic variability at the molecular level was found between isolates of P. viridiflava originated from different host species as well as among isolates from the same host. Our results provide a basis for more comprehensive understanding of the biology, sources and shifts in genetic diversity and evolution of P. viridiflava populations and should support the development of molecular identification tools and epidemiological studies in diseases caused by this species.

  20. Chain length and temperature dependence of alkanedithiol molecular conductance under ultra high vacuum.

    Science.gov (United States)

    Pires, Ellis; Macdonald, J Emyr; Elliott, Martin

    2013-10-07

    We report scanning tunnelling microscope (STM) measurements of the single molecule conductance of α,ω-alkanedithiols for a large range of molecular chain lengths (N = 3-10) and temperatures (180-390 K) under ultra high vacuum. Two STM-based measurement techniques were employed on molecules trapped between tip and substrate: (i) the well established current-distance or I(z) technique and (ii) a new I(V,z) technique in which the current-voltage characteristics are determined as the tip-substrate distance z is varied. Low, medium, and high conductance groups were observed for each molecular length, which were temperature independent over the range examined, consistent with off-resonance tunnelling. For N > 4 the current-voltage characteristics and conductance trend with chain length is well described using a simple rectangular tunnel barrier model with parameters in excellent agreement with previously reported values. However, both 1,3-propanedithiol (N = 3) and 1,4-butanedithiol (N = 4) show an anomalous behaviour which is qualitatively similar to, but much less pronounced than, that reported by Haiss et al. (Phys. Chem. Chem. Phys., 2009, 11, 10831) for measurements performed under air and nitrogen gas.

  1. Molecular mechanisms underlying cardiac antihypertrophic and antifibrotic effects of natriuretic peptides.

    Science.gov (United States)

    Calvieri, Camilla; Rubattu, Speranza; Volpe, Massimo

    2012-01-01

    Natriuretic peptides (NPs) exert well-characterized protective effects on the cardiovascular system, such as vasorelaxation, natri- and diuresis, increase of endothelial permeability, and inhibition of renin-angiotensin-aldosterone system. It has been reported that they also possess antihypertrophic and antifibrotic properties and contribute actively to cardiac remodeling. As a consequence, they are involved in several aspects of cardiovascular diseases. Antihypertrophic and antifibrotic actions of NPs appear to be mediated by specific signaling pathways within a more complex cellular network. Elucidation of the molecular mechanisms underlying the effects of NPs on cardiac remodeling represents an important research objective in order to gain more insights on the complex network leading to cardiac hypertrophy, ventricular dysfunction, and transition to heart failure, and in the attempt to develop novel therapeutic agents. The aim of the present article is to review well-characterized molecular mechanisms underlying the antihypertrophic and antifibrotic effects of NPs in the heart that appear to be mainly mediated by guanylyl cyclase type A receptor. In particular, we discuss the calcineurin/NFAT, the sodium exchanger NHE-1, and the TGFβ1/Smad signaling pathways. The role of guanylyl cyclase type B receptor, along with the emerging functional significance of natriuretic peptide receptor type C as mediators of CNP antihypertrophic and antifibrotic actions in the heart are also considered.

  2. Molecular tools for sterile sperm detection to monitor Ceratitis capitata populations under SIT programmes.

    Science.gov (United States)

    Juan-Blasco, María; Sabater-Muñoz, Beatriz; Argilés, Rafael; Jacas, Josep A; Castañera, Pedro; Urbaneja, Alberto

    2013-07-01

    The success of an area-wide sterile insect technique (SIT) programme against Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) relies on the mating success of sterile males in the field. Limited information is available about the effectiveness of sterile males in achieving mates with wild females and how these matings contribute to reducing wild populations. To this end, firstly a mating competition test was performed in the laboratory with different release ratios (1:1:0, 1:1:1, 1:1:5, 1:1:10 and 1:1:20 for wild females:wild males:sterile VIENNA-8 males respectively) and different host fruit. Secondly, the same release ratios were evaluated under semi-natural conditions on caged trees and on sentinel host. By means of molecular markers, VIENNA-8 male sperm was positively detected in those females exposed to the male ratios 1:5, 1:10 and 1:20 in the laboratory. In the field test, sterile VIENNA-8 male matings and the C. capitata progeny on apples were positively correlated with the ratio of sterile males released and with the percentage of sterile matings respectively. These results confirm the validity of using the molecular detection of VIENNA-8 male sperm to predict the C. capitata population under semi-natural conditions. Implications of these results in measuring the efficacy of an SIT programme are discussed. © 2012 Society of Chemical Industry.

  3. Perfusion patterns of metastatic gastrointestinal stromal tumor lesions under specific molecular therapy

    Energy Technology Data Exchange (ETDEWEB)

    Schlemmer, Marcus [Department of Internal Medicine III, University Hospitals-Grosshadern, Ludwig Maximilians University Munich, Marchioninistr. 15, 81377 Munich (Germany); Sourbron, Steven P. [Institute of Clinical Radiology, University Hospitals-Grosshadern, Ludwig Maximilians University Munich, Marchioninistr. 15, 81377 Munich (Germany); Schinwald, Nicole [Department of Internal Medicine III, University Hospitals-Grosshadern, Ludwig Maximilians University Munich, Marchioninistr. 15, 81377 Munich (Germany); Nikolaou, Konstantin; Becker, Christoph R.; Reiser, Maximilian F. [Institute of Clinical Radiology, University Hospitals-Grosshadern, Ludwig Maximilians University Munich, Marchioninistr. 15, 81377 Munich (Germany); Berger, Frank, E-mail: Frank.Berger@med.uni-muenchen.de [Institute of Clinical Radiology, University Hospitals-Grosshadern, Ludwig Maximilians University Munich, Marchioninistr. 15, 81377 Munich (Germany)

    2011-02-15

    Rationale and objective: The aim of this pilot study was the evaluation of CT perfusion patterns in metastatic GIST lesions under specific molecular therapy with sunitinib or imatinib both in responders and non-responders. Patients and methods: 24 patients with metastatic GIST under tyrosine kinase inhibition were retrospectively evaluated. A total of 46 perfusion and venous phase CT scans were acquired. Volume of distribution, blood flow, blood volume, permeability and hepatic perfusion index measurements of metastatic lesions were carried out. Lesions were classified as 'good response' or 'poor response' to therapy, and perfusion parameters were compared for these two types of lesions. Results: 24 patients were evaluated. In the extrahepatic abdominal lesions (N = 15), good responders showed significant lower perfusion values than poor responders (volume of distribution: 3.3 {+-} 2.0 vs. 13.0 {+-} 1.8 ml/100 ml, p = 0.001). The same tendency was observed in intrahepatic lesions (N = 31) (liver volume of distribution: 2.1 {+-} 0.3 vs. 7.1 {+-} 1.3 ml/100 ml, p = 0.003); (hepatic perfusion index: 24.3 {+-} 7.9 vs. 76.1 {+-} 1.5%, p = 0.0001). Conclusion: Our data indicate that there are characteristic perfusion patterns of metastatic GIST lesions showing a good or poor response to molecular pharmacotherapy. Perfusion should be further evaluated in cross-sectional imaging studies as a possible biomarker for treatment response in targeted therapies of GIST.

  4. Energy level alignment at planar organic heterojunctions: influence of contact doping and molecular orientation

    Science.gov (United States)

    Opitz, Andreas

    2017-04-01

    Planar organic heterojunctions are widely used in photovoltaic cells, light-emitting diodes, and bilayer field-effect transistors. The energy level alignment in the devices plays an important role in obtaining the aspired gap arrangement. Additionally, the π-orbital overlap between the involved molecules defines e.g. the charge-separation efficiency in solar cells due to charge-transfer effects. To account for both aspects, direct/inverse photoemission spectroscopy and near edge x-ray absorption fine structure spectroscopy were used to determine the energy level landscape and the molecular orientation at prototypical planar organic heterojunctions. The combined experimental approach results in a comprehensive model for the electronic and morphological characteristics of the interface between the two investigated molecular semiconductors. Following an introduction on heterojunctions used in devices and on energy levels of organic materials, the energy level alignment of planar organic heterojunctions will be discussed. The observed energy landscape is always determined by the individual arrangement between the energy levels of the molecules and the work function of the electrode. This might result in contact doping due to Fermi level pinning at the electrode for donor/acceptor heterojunctions, which also improves the solar cell efficiency. This pinning behaviour can be observed across an unpinned interlayer and results in charge accumulation at the donor/acceptor interface, depending on the transport levels of the respective organic semiconductors. Moreover, molecular orientation will affect the energy levels because of the anisotropy in ionisation energy and electron affinity and is influenced by the structural compatibility of the involved molecules at the heterojunction. High structural compatibility leads to π-orbital stacking between different molecules at a heterojunction, which is of additional interest for photovoltaic active interfaces and for ground

  5. An order level inventory model under two level storage system with fuzzy demand

    Directory of Open Access Journals (Sweden)

    Sakrar S.

    2013-01-01

    Full Text Available Deterministic inventory model with two levels of storage has been studied by numerous authors. In this paper we developed a fuzzy inventory model with two ware houses (one is the existing storage known as own warehouse (OW and the other is hired on rental basis known as rented warehouse (RW. The model allows constant levels of item deterioration in both houses. The stock is transferred from RW to OW in continuous release pattern and the associated transportation cost is taken into account. To make the model more realistic in nature, fuzzy demand has been considered. Using α-cut for defuzzification, the total variable cost per unit time is derived. Therefore, the problem is reduced to crisp annual costs. The multi-objective model is solved by Global Criteria Method supported by GRG (Generalized Reduced Gradient Technique, which is illustrated by a numerical example.

  6. Imaging and Tuning Molecular Levels at the Surface of a Gated Graphene Device

    Science.gov (United States)

    2014-01-01

    Gate-controlled tuning of the charge carrier density in graphene devices provides new opportunities to control the behavior of molecular adsorbates. We have used scanning tunneling microscopy (STM) and spectroscopy (STS) to show how the vibronic electronic levels of 1,3,5-tris(2,2-dicyanovinyl)benzene molecules adsorbed onto a graphene/BN/SiO2 device can be tuned via application of a backgate voltage. The molecules are observed to electronically decouple from the graphene layer, giving rise to well-resolved vibronic states in dI/dV spectroscopy at the single-molecule level. Density functional theory (DFT) and many-body spectral function calculations show that these states arise from molecular orbitals coupled strongly to carbon–hydrogen rocking modes. Application of a back-gate voltage allows switching between different electronic states of the molecules for fixed sample bias. PMID:24746016

  7. Deuterium-hydrogen isotopic exchange in water molecules adsorbed on Teflon under atomic-molecular hydrogen beams

    International Nuclear Information System (INIS)

    Grankin, V.P.; Savinkov, N.A.; Styrov, V.V.; Tyurin, Yu.I.

    1994-01-01

    Processes of deuterium-hydrogen exchange in the course of interaction between hydrogen molecular beam and H+H 2 atomic-molecular beam with adsorbed water molecules from D 2 O, HDO, H 2 O on Teflon have been studied. Desorption of the above molecules into vacuum, as well as their desorption under conditions of molecular and atomic-molecular hydrogen beam effect on Teflon surface have been investigated experimentally. Relative probabilities of hydrogen isotopes desorption from Teflon surface have been defined, relative probabilities and cross sections of diverse reactions of isotopic exchange have been found. 2 refs.; 3 figs

  8. A probe to study the toxic interaction of tartrazine with bovine hemoglobin at the molecular level.

    Science.gov (United States)

    Li, Yating; Wei, Haoran; Liu, Rutao

    2014-03-01

    Tartrazine is an artificial azo dye commonly used in food products, but tartrazine in the environment is potentially harmful. The toxic interaction between tartrazine and bovine hemoglobin (BHb) was investigated using fluorescence, synchronous fluorescence, UV-vis absorption, circular dichroism (CD) and molecular modeling techniques under simulated physiological conditions. The fluorescence data showed that tartrazine can bind with BHb to form a complex. The binding process was a spontaneous molecular interaction, in which van der Waals' forces and hydrogen bonds played major roles. Molecular docking results showed that the hydrogen bonds exist between the oxygen atoms at position 31 of tartrazine and the nitrogen atom NZ7 on Lys99, and also between the oxygen atoms at position 15 of tartrazine and the nitrogen atom NZ7 on Lys104, Lys105. The results of UV-vis and CD spectra revealed that tartrazine led to conformational changes in BHb, including loosening of the skeleton structure and decreasing α helix in the secondary structure. The synchronous fluorescence experiment revealed that tartrazine binds into the hemoglobin central cavity, and this was verified using a molecular modeling study. Copyright © 2013 John Wiley & Sons, Ltd.

  9. Global, regional, and national levels of neonatal, infant, and under-5 mortality during 1990-2013

    DEFF Research Database (Denmark)

    Wang, Haidong; Liddell, Chelsea A; Coates, Matthew M

    2014-01-01

    BACKGROUND: Remarkable financial and political efforts have been focused on the reduction of child mortality during the past few decades. Timely measurements of levels and trends in under-5 mortality are important to assess progress towards the Millennium Development Goal 4 (MDG 4) target of redu...... levels of under-5 mortality in 2030. FUNDING: Bill & Melinda Gates Foundation, US Agency for International Development....

  10. Seroprofiling at the Candida albicans protein species level unveils an accurate molecular discriminator for candidemia.

    Science.gov (United States)

    Pitarch, Aida; Nombela, César; Gil, Concha

    2016-02-16

    Serum antibodies to specific Candida proteins have been reported as potential diagnostic biomarkers for candidemia. However, their diagnostic usefulness at the protein species level has hardly been examined. Using serological proteome analysis, we explored the IgG-antibody responses to Candida albicans protein species in candidemia and control patients. We found that 87 discrete protein species derived from 34 unique proteins were IgG-targets, although only 43 of them were differentially recognized by candidemia and control sera. An increase in the speciation of the immunome, connectivity and modularity of antigenic species co-recognition networks, and heterogeneity of antigenic species recognition patterns was associated with candidemia. IgG antibodies to certain discrete protein species were better predictors of candidemia than those to their corresponding proteins. A molecular discriminator delineated from the combined fingerprints of IgG antibodies to two distinct species of phosphoglycerate kinase and enolase accurately classified candidemia and control patients. These results provide new insight into the anti-Candida IgG-antibody response development in candidemia, and demonstrate that an immunoproteomic signature at the molecular level may be useful for its diagnosis. Our study further highlights the importance of defining pathogen-specific antigens at the chemical and molecular level for their potential application as immunodiagnostic reagents or even vaccine candidates.

  11. Molecular Ecological Basis of Grasshopper (Oedaleus asiaticus) Phenotypic Plasticity under Environmental Selection

    Science.gov (United States)

    Qin, Xinghu; Hao, Kun; Ma, Jingchuan; Huang, Xunbing; Tu, Xiongbing; Ali, Md. Panna; Pittendrigh, Barry R.; Cao, Guangchun; Wang, Guangjun; Nong, Xiangqun; Whitman, Douglas W.; Zhang, Zehua

    2017-01-01

    While ecological adaptation in insects can be reflected by plasticity of phenotype, determining the causes and molecular mechanisms for phenotypic plasticity (PP) remains a crucial and still difficult question in ecology, especially where control of insect pests is involved. Oedaleus asiaticus is one of the most dominant pests in the Inner Mongolia steppe and represents an excellent system to study phenotypic plasticity. To better understand ecological factors affecting grasshopper phenotypic plasticity and its molecular control, we conducted a full transcriptional screening of O. asiaticus grasshoppers reared in four different grassland patches in Inner Mongolia. Grasshoppers showed different degrees of PP associated with unique gene expressions and different habitat plant community compositions. Grasshopper performance variables were susceptible to habitat environment conditions and closely associated with plant architectures. Intriguingly, eco-transcriptome analysis revealed five potential candidate genes playing important roles in grasshopper performance, with gene expression closely relating to PP and plant community factors. By linking the grasshopper performances to gene profiles and ecological factors using canonical regression, we first demonstrated the eco-transcriptomic architecture (ETA) of grasshopper phenotypic traits (ETAGPTs). ETAGPTs revealed plant food type, plant density, coverage, and height were the main ecological factors influencing PP, while insect cuticle protein (ICP), negative elongation factor A (NELFA), and lactase-phlorizin hydrolase (LCT) were the key genes associated with PP. Our study gives a clear picture of gene-environment interaction in the formation and maintenance of PP and enriches our understanding of the transcriptional events underlying molecular control of rapid phenotypic plasticity associated with environmental variability. The findings of this study may also provide new targets for pest control and highlight the

  12. Molecular Ecological Basis of Grasshopper (Oedaleus asiaticus Phenotypic Plasticity under Environmental Selection

    Directory of Open Access Journals (Sweden)

    Xinghu Qin

    2017-10-01

    Full Text Available While ecological adaptation in insects can be reflected by plasticity of phenotype, determining the causes and molecular mechanisms for phenotypic plasticity (PP remains a crucial and still difficult question in ecology, especially where control of insect pests is involved. Oedaleus asiaticus is one of the most dominant pests in the Inner Mongolia steppe and represents an excellent system to study phenotypic plasticity. To better understand ecological factors affecting grasshopper phenotypic plasticity and its molecular control, we conducted a full transcriptional screening of O. asiaticus grasshoppers reared in four different grassland patches in Inner Mongolia. Grasshoppers showed different degrees of PP associated with unique gene expressions and different habitat plant community compositions. Grasshopper performance variables were susceptible to habitat environment conditions and closely associated with plant architectures. Intriguingly, eco-transcriptome analysis revealed five potential candidate genes playing important roles in grasshopper performance, with gene expression closely relating to PP and plant community factors. By linking the grasshopper performances to gene profiles and ecological factors using canonical regression, we first demonstrated the eco-transcriptomic architecture (ETA of grasshopper phenotypic traits (ETAGPTs. ETAGPTs revealed plant food type, plant density, coverage, and height were the main ecological factors influencing PP, while insect cuticle protein (ICP, negative elongation factor A (NELFA, and lactase-phlorizin hydrolase (LCT were the key genes associated with PP. Our study gives a clear picture of gene-environment interaction in the formation and maintenance of PP and enriches our understanding of the transcriptional events underlying molecular control of rapid phenotypic plasticity associated with environmental variability. The findings of this study may also provide new targets for pest control and

  13. Thermal conductivity of graphene nanoribbons under shear deformation: A molecular dynamics simulation

    Science.gov (United States)

    Zhang, Chao; Hao, Xiao-Li; Wang, Cui-Xia; Wei, Ning; Rabczuk, Timon

    2017-01-01

    Tensile strain and compress strain can greatly affect the thermal conductivity of graphene nanoribbons (GNRs). However, the effect of GNRs under shear strain, which is also one of the main strain effect, has not been studied systematically yet. In this work, we employ reverse nonequilibrium molecular dynamics (RNEMD) to the systematical study of the thermal conductivity of GNRs (with model size of 4 nm × 15 nm) under the shear strain. Our studies show that the thermal conductivity of GNRs is not sensitive to the shear strain, and the thermal conductivity decreases only 12–16% before the pristine structure is broken. Furthermore, the phonon frequency and the change of the micro-structure of GNRs, such as band angel and bond length, are analyzed to explore the tendency of thermal conductivity. The results show that the main influence of shear strain is on the in-plane phonon density of states (PDOS), whose G band (higher frequency peaks) moved to the low frequency, thus the thermal conductivity is decreased. The unique thermal properties of GNRs under shear strains suggest their great potentials for graphene nanodevices and great potentials in the thermal managements and thermoelectric applications. PMID:28120921

  14. Thermal conductivity of graphene nanoribbons under shear deformation: A molecular dynamics simulation.

    Science.gov (United States)

    Zhang, Chao; Hao, Xiao-Li; Wang, Cui-Xia; Wei, Ning; Rabczuk, Timon

    2017-01-25

    Tensile strain and compress strain can greatly affect the thermal conductivity of graphene nanoribbons (GNRs). However, the effect of GNRs under shear strain, which is also one of the main strain effect, has not been studied systematically yet. In this work, we employ reverse nonequilibrium molecular dynamics (RNEMD) to the systematical study of the thermal conductivity of GNRs (with model size of 4 nm × 15 nm) under the shear strain. Our studies show that the thermal conductivity of GNRs is not sensitive to the shear strain, and the thermal conductivity decreases only 12-16% before the pristine structure is broken. Furthermore, the phonon frequency and the change of the micro-structure of GNRs, such as band angel and bond length, are analyzed to explore the tendency of thermal conductivity. The results show that the main influence of shear strain is on the in-plane phonon density of states (PDOS), whose G band (higher frequency peaks) moved to the low frequency, thus the thermal conductivity is decreased. The unique thermal properties of GNRs under shear strains suggest their great potentials for graphene nanodevices and great potentials in the thermal managements and thermoelectric applications.

  15. Low Molecular Weight Fucoidan Inhibits Tumor Angiogenesis through Downregulation of HIF-1/VEGF Signaling under Hypoxia

    Directory of Open Access Journals (Sweden)

    Meng-Chuan Chen

    2015-07-01

    Full Text Available Activation of hypoxia-induced hypoxia-inducible factors-1 (HIF-1 plays a critical role in promoting tumor angiogenesis, growth and metastasis. Low molecular weight fucoidan (LMWF is prepared from brown algae, and exhibits anticancer activity. However, whether LMWF attenuates hypoxia-induced angiogenesis in bladder cancer cells and the molecular mechanisms involved remain unclear. This is the first study to demonstrate that LMWF can inhibit hypoxia-stimulated H2O2 formation, HIF-1 accumulation and transcriptional activity vascular endothelial growth factor (VEGF secretion, and the migration and invasion in hypoxic human bladder cancer cells (T24 cells. LMWF also downregulated hypoxia-activated phosphorylation of PI3K/AKT/mTOR/p70S6K/4EBP-1 signaling in T24 cells. Blocking PI3K/AKT or mTOR activity strongly diminished hypoxia-induced HIF-1α expression and VEGF secretion in T24 cells, supporting the involvement of PI3K/AKT/mTOR in the induction of HIF-1α and VEGF. Additionally, LMWF significantly attenuated angiogenesis in vitro and in vivo evidenced by reduction of tube formation of hypoxic human umbilical vascular endothelial cells and blood capillary generation in the tumor. Similarly, administration of LMWF also inhibited the HIF-1α and VEGF expression in vivo, accompanied by a reduction of tumor growth. In summary, under hypoxia conditions, the antiangiogenic activity of LMWF in bladder cancer may be associated with suppressing HIF-1/VEGF-regulated signaling pathway.

  16. Molecular mechanisms underlying monosynaptic sensory-motor circuit development in the spinal cord.

    Science.gov (United States)

    Imai, Fumiyasu; Yoshida, Yutaka

    2018-04-01

    Motor behaviors are precisely controlled by the integration of sensory and motor systems in the central nervous system (CNS). Proprioceptive sensory neurons, key components of the sensory system, are located in the dorsal root ganglia and project axons both centrally to the spinal cord and peripherally to muscles and tendons, communicating peripheral information about the body to the CNS. Changes in muscle length detected by muscle spindles, and tension variations in tendons conveyed by Golgi tendon organs, are communicated to the CNS through group Ia /II, and Ib proprioceptive sensory afferents, respectively. Group Ib proprioceptive sensory neurons connect with motor neurons indirectly through spinal interneurons, whereas group Ia/II axons form both direct (monosynaptic) and indirect connections with motor neurons. Although monosynaptic sensory-motor circuits between spindle proprioceptive sensory neurons and motor neurons have been extensively studied since 1950s, the molecular mechanisms underlying their formation and upkeep have only recently begun to be understood. We will discuss our current understanding of the molecular foundation of monosynaptic circuit development and maintenance involving proprioceptive sensory neurons and motor neurons in the mammalian spinal cord. Developmental Dynamics 247:581-587, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  17. Equations of states for an ionic liquid under high pressure: A molecular dynamics simulation study

    International Nuclear Information System (INIS)

    Ribeiro, Mauro C.C.; Pádua, Agílio A.H.; Gomes, Margarida F.C.

    2014-01-01

    Highlights: • We compare different equation of states, EoS, for an ionic liquid under high pressure. • Molecular dynamics, MD, simulations have been used to evaluate the best EoS. • MD simulations show that a group contribution model can be extrapolated to P ∼ 1.0 GPa. • A perturbed hard-sphere EoS also fits the densities calculated by MD simulations. - Abstract: The high-pressure dependence of density given by empirical equation of states (EoS) for the ionic liquid 1-butyl-3-methylimidazolium trifluoromethanesulfonate (or triflate), [C 4 C 1 im][TfO], is compared with results obtained by molecular dynamics (MD) simulations. Two EoS proposed for [C 4 C 1 im][TfO] in the pressure range of tens of MPa, which give very different densities when extrapolated to pressures beyond the original experiments, are compared with a group contribution model (GCM). The MD simulations provide support that one of the empirical EoS and the GCM is valid in the pressure range of hundreds of MPa. As an alternative to these EoS that are based on modified Tait equations, it is shown that a perturbed hard-sphere EoS based on the Carnahan–Starling–van der Waals equation also fits the densities calculated by MD simulations of [C 4 C 1 im][TfO] up to ∼1.0 GPa

  18. Integrative analysis revealed the molecular mechanism underlying RBM10-mediated splicing regulation.

    Science.gov (United States)

    Wang, Yongbo; Gogol-Döring, Andreas; Hu, Hao; Fröhler, Sebastian; Ma, Yunxia; Jens, Marvin; Maaskola, Jonas; Murakawa, Yasuhiro; Quedenau, Claudia; Landthaler, Markus; Kalscheuer, Vera; Wieczorek, Dagmar; Wang, Yang; Hu, Yuhui; Chen, Wei

    2013-09-01

    RBM10 encodes an RNA binding protein. Mutations in RBM10 are known to cause multiple congenital anomaly syndrome in male humans, the TARP syndrome. However, the molecular function of RBM10 is unknown. Here we used PAR-CLIP to identify thousands of binding sites of RBM10 and observed significant RBM10-RNA interactions in the vicinity of splice sites. Computational analyses of binding sites as well as loss-of-function and gain-of-function experiments provided evidence for the function of RBM10 in regulating exon skipping and suggested an underlying mechanistic model, which could be subsequently validated by minigene experiments. Furthermore, we demonstrated the splicing defects in a patient carrying an RBM10 mutation, which could be explained by disrupted function of RBM10 in splicing regulation. Overall, our study established RBM10 as an important regulator of alternative splicing, presented a mechanistic model for RBM10-mediated splicing regulation and provided a molecular link to understanding a human congenital disorder. © 2013 The Authors. Published by John Wiley and Sons, Ltd on behalf of EMBO.

  19. Molecular Mechanisms Underlying Renin-Angiotensin-Aldosterone System Mediated Regulation of BK Channels

    Directory of Open Access Journals (Sweden)

    Zhen-Ye Zhang

    2017-09-01

    Full Text Available Large-conductance calcium-activated potassium channels (BK channels belong to a family of Ca2+-sensitive voltage-dependent potassium channels and play a vital role in various physiological activities in the human body. The renin-angiotensin-aldosterone system is acknowledged as being vital in the body's hormone system and plays a fundamental role in the maintenance of water and electrolyte balance and blood pressure regulation. There is growing evidence that the renin-angiotensin-aldosterone system has profound influences on the expression and bioactivity of BK channels. In this review, we focus on the molecular mechanisms underlying the regulation of BK channels mediated by the renin-angiotensin-aldosterone system and its potential as a target for clinical drugs.

  20. Molecular dynamics simulation of ZnO wurtzite phase under high and low pressures and temperatures

    Science.gov (United States)

    Chergui, Y.; Aouaroun, T.; Hadley, M. J.; Belkada, R.; Chemam, R.; Mekki, D. E.

    2017-11-01

    Isothermal and isobaric ensembles behaviours of ZnO wurtzite phase have been investigated, by parallel molecular dynamics method and using Buckingham potential, which contains long-range Coulomb, repulsive exponential, and attractive dispersion terms. To conduct our calculations, we have used dl_poly 4 software, under which the method is implemented. We have examined the influence of the temperature and pressure on molar volume in the ranges of 300–3000 K and 0–200 GPa. Isothermal-isobaric relationships, fluctuations, standard error, equilibrium time, molar volume and its variation versus time are predicted and analyzed. Our results are close to available experimental data and theoretical results.

  1. Energy dissipation in non-isothermal molecular dynamics simulations of confined liquids under shear.

    Science.gov (United States)

    Berro, Hassan; Fillot, Nicolas; Vergne, Philippe; Tokumasu, Takashi; Ohara, Taku; Kikugawa, Gota

    2011-10-07

    Energy is commonly dissipated in molecular dynamics simulations by using a thermostat. In non-isothermal shear simulations of confined liquids, the choice of the thermostat is very delicate. We show in this paper that under certain conditions, the use of classical thermostats can lead to an erroneous description of the dynamics in the confined system. This occurs when a critical shear rate is surpassed as the thermo-viscous effects become prominent. In this high-shear-high-dissipation regime, advanced dissipation methods including a novel one are introduced and compared. The MD results show that the physical modeling of both the accommodation of the surface temperature to liquid heating and the heat conduction through the confining solids is essential. The novel method offers several advantages on existing ones including computational efficiency and easiness of application for complex systems. © 2011 American Institute of Physics

  2. Prediction of physical properties of water under extremely supercritical conditions: A molecular dynamics study

    Science.gov (United States)

    Sakuma, Hiroshi; Ichiki, Masahiro; Kawamura, Katsuyuki; Fuji-ta, Kiyoshi

    2013-04-01

    The physical properties of water under a wide range of pressure and temperature conditions are important in fundamental physics, chemistry, and geoscience. Molecular simulations are useful for predicting and understanding the physical properties of water at phases extremely different from ambient conditions. In this study, we developed a new five-site flexible induced point charge model to predict the density, static dielectric constant, and transport properties of water in the extremely supercritical phase at high temperatures and pressures of up to 2000 K and 2000 MPa. The model satisfactorily reproduced the density, radial distribution function, static dielectric constant, reorientation time, and self-diffusion coefficients of water above the critical points. We also developed a database of the static dielectric constant, which is useful for discussing the electrical conductivity of aqueous fluids in the earth's crust and mantle.

  3. Thermal buckling behavior of defective CNTs under pre-load: A molecular dynamics study.

    Science.gov (United States)

    Mehralian, Fahimeh; Tadi Beni, Yaghoub; Kiani, Yaser

    2017-05-01

    Current study is concentrated on the extraordinary properties of defective carbon nanotubes (CNTs). The role of vacancy defects in thermal buckling response of precompressed CNTs is explored via molecular dynamics (MD) simulations. Defective CNTs are initially compressed at a certain ratio of their critical buckling strain and then undergo a uniform temperature rise. Comprehensive study is implemented on both armchair and zigzag CNTs with different vacancy defects including monovacancy, symmetric bivacancy and asymmetric bivacancy. The results reveal that defects have a pronounced impact on the buckling behavior of CNTs; interestingly, defective CNTs under compressive pre-load show higher resistance to thermal buckling than pristine ones. In the following, the buckling response of defective CNTs is shown to be dependent on the vacancy defects, location of defects and chirality. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Void effect on mechanical properties of copper nanosheets under biaxial tension by molecular dynamics method

    Science.gov (United States)

    Yang, Zailin; Yang, Qinyou; Zhang, Guowei; Yang, Yong

    2018-03-01

    The relationship between void size/location and mechanical behavior under biaxial loading of copper nanosheets containing voids are investigated by molecular dynamics method. The void location and the void radius on the model are discussed in the paper. The main reason of break is discovered by the congruent relationship between the shear stress and its dislocations. Dislocations are nucleated at the corner of system and approached to the center of void with increased deformation. Here, a higher stress is required to fail the voided sheets when smaller voids are utilized. The void radius influences the time of destruction. The larger the void radius is, the lower the shear stress and the earlier the model breaks. The void location impacts the dislocation distribution.

  5. Molecular dynamics study of radiation damage and microstructure evolution of zigzag single-walled carbon nanotubes under carbon ion incidence

    Science.gov (United States)

    Li, Huan; Tang, Xiaobin; Chen, Feida; Huang, Hai; Liu, Jian; Chen, Da

    2016-07-01

    The radiation damage and microstructure evolution of different zigzag single-walled carbon nanotubes (SWCNTs) were investigated under incident carbon ion by molecular dynamics (MD) simulations. The radiation damage of SWCNTs under incident carbon ion with energy ranging from 25 eV to 1 keV at 300 K showed many differences at different incident sites, and the defect production increased to the maximum value with the increase in incident ion energy, and slightly decreased but stayed fairly stable within the majority of the energy range. The maximum damage of SWCNTs appeared when the incident ion energy reached 200 eV and the level of damage was directly proportional to incident ion fluence. The radiation damage was also studied at 100 K and 700 K and the defect production decreased distinctly with rising temperature because radiation-induced defects would anneal and recombine by saturating dangling bonds and reconstructing carbon network at the higher temperature. Furthermore, the stability of a large-diameter tube surpassed that of a thin one under the same radiation environments.

  6. The timing of molecular and morphological changes underlying reproductive transitions in wild tomatoes (Solanum sect. Lycopersicon).

    Science.gov (United States)

    Vosters, S L; Jewell, C P; Sherman, N A; Einterz, F; Blackman, B K; Moyle, L C

    2014-04-01

    Molecular mechanisms underlying the transition from genetic self-incompatibility to self-compatibility are well documented, but the evolution of other reproductive trait changes that accompany shifts in reproductive strategy (mating system) remains comparatively under-investigated. A notable exception is the transition from exserted styles to styles with recessed positions relative to the anthers in wild tomatoes (Solanum Section Lycopersicon). This phenotypic change has been previously attributed to a specific mutation in the promoter of a gene that influences style length (style2.1); however, whether this specific regulatory mutation arose concurrently with the transition from long to short styles, and whether it is causally responsible for this phenotypic transition, has been poorly investigated across this group. To address this gap, we assessed 74 accessions (populations) from 13 species for quantitative genetic variation in floral and reproductive traits as well as the presence/absence of deletions at two different locations (StyleD1 and StyleD2) within the regulatory region upstream of style2.1. We confirmed that the putatively causal deletion variant (a 450-bp deletion at StyleD1) arose within self-compatible lineages. However, the variation and history of both StyleD1 and StyleD2 was more complex than previously inferred. In particular, although StyleD1 was statistically associated with differences in style length and stigma exsertion across all species, we found no evidence for this association within two species polymorphic for the StyleD1 mutation. We conclude that the previous association detected between phenotypic and molecular differences is most likely due to a phylogenetic association rather than a causal mechanistic relationship. Phenotypic variation in style length must therefore be due to other unexamined linked variants in the style2.1 regulatory region. © 2014 John Wiley & Sons Ltd.

  7. [Teaching research of Molecular Pharmacognosy for talent development in industry of Chinese medicinal materials under new situation].

    Science.gov (United States)

    Guo, Wan-Li; Qi, Zhe-Chen; Zhang, Xiao-Dan; Sheng, Qing; Liang, Zong-Suo

    2017-01-01

    The industry of Chinese medicinal materials is going through another high-level development stage with some important files issued by Chinese government in the past months, such as "the protection and development plans of Chinese medicinal materials (2015-2020)" and "the strategic development plans of Chinese medicine (2016-2030)". In addition, the effect of "TU Youyou" will not only improve the industry development, but also indicates the increasing international competition intensely. Therefore, one of the core problems of the sustainable-development industry is the training of senior talents under the "New Situation" with opportunity and intense competition. As one of the forefront courses of Chinese Pharmacology, Molecular Pharmacognosy (MP) is a new interdisciplinary science, which integrates the pharmacognosy and molecular biology, and combines many discipline theories and technological systems. MP not only inherits the traditional concepts,but also makes up for the shortages of pharmacognosy, and improves the development of pharmacognosy. Thus, these are importance of MP for cultivation of senior talents, and also the difficult teaching points of MP with no unified teaching mode. We will, in this paper, discuss the possible teaching modes through several aspects for talent cultivation and meeting the needs of social and industry development, such as teaching state of MP, the education of undergraduate and graduate students, social identity, and self renewal of curriculum theories and practice. Copyright© by the Chinese Pharmaceutical Association.

  8. Enrichment of serum low-molecular-weight proteins using C18 absorbent under urea/dithiothreitol denatured environment.

    Science.gov (United States)

    Wu, Jing; An, Yuan; Pu, Hai; Shan, Yue; Ren, Xiaoqing; An, Mingrui; Wang, Qingsong; Wei, Shicheng; Ji, Jianguo

    2010-03-01

    Serum low-molecular-weight proteins (LMWPs, molecular weightbody physiological and pathological situations, whereas many difficulties are encountered when enriching and fractionating them. Using C(18) absorbent (100 A) enrichment and fractionation under urea/dithiothreitol (DTT) denatured environment followed by 60% acetonitrile (ACN) elution, serum LMWPs could be enriched more than 100-fold and were evaluated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), two-dimensional gel electrophoresis (2-DE), and isotope-coded affinity tag (ICAT) labeling quantification. Proteins existing in human serum at low nanograms/milliliter (ng/ml) levels, such as myeloid-related proteins (MRPs), could be identified directly from 2-DE coupled with matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF MS) and LTQ-Orbitrap MS. Sixteen proteins were confidentially identified and quantified using ICAT labeling and liquid chromatography-tandem mass spectrometry (LC-MS/MS). By virtue of its easy operation and high reproducibility to process large quantity complex serum samples, this method has potential uses in enriching LMWPs either in serum or in cell and tissue samples. Copyright 2009 Elsevier Inc. All rights reserved.

  9. Molecular-level mechanisms of vibrational frequency shifts in a polar liquid.

    Science.gov (United States)

    Morales, Christine M; Thompson, Ward H

    2011-06-16

    A molecular-level analysis of the origins of the vibrational frequency shifts of the CN stretching mode in neat liquid acetonitrile is presented. The frequency shifts and infrared spectrum are calculated using a perturbation theory approach within a molecular dynamics simulation and are in good agreement with measured values reported in the literature. The resulting instantaneous frequency of each nitrile group is decomposed into the contributions from each molecule in the liquid and by interaction type. This provides a detailed picture of the mechanisms of frequency shifts, including the number of surrounding molecules that contribute to the shift, the relationship between their position and relative contribution, and the roles of electrostatic and van der Waals interactions. These results provide insight into what information is contained in infrared (IR) and Raman spectra about the environment of the probed vibrational mode. © 2011 American Chemical Society

  10. Proteomics analysis reveals the molecular mechanism underlying the transition from primary to secondary growth of poplar.

    Science.gov (United States)

    Li, Yuan; Jin, Feng; Chao, Qing; Wang, Bai-Chen

    2017-06-01

    Wood is the most important natural source of energy and also provides fuel and fiber. Considering the significant role of wood, it is critical to understand how wood is formed. Integration of knowledge about wood development at the cellular and molecular levels will allow more comprehensive understanding of this complex process. In the present study, we used a comparative proteomic approach to investigate the differences in protein profiles between primary and secondary growth in young poplar stems using tandem mass tag (TMT)-labeling. More than 10,816 proteins were identified, and, among these, 3106 proteins were differentially expressed during primary to secondary growth. Proteomic data were validated using a combination of histochemical staining, enzyme activity assays, and quantitative real-time PCR. Bioinformatics analysis revealed that these differentially expressed proteins are related to various metabolic pathways, mainly including signaling, phytohormones, cell cycle, cell wall, secondary metabolism, carbohydrate and energy metabolism, and protein metabolism as well as redox and stress pathways. This large proteomics dataset will be valuable for uncovering the molecular changes occurring during the transition from primary to secondary growth. Further, it provides new and accurate information for tree breeding to modify wood properties. Copyright © 2017 Elsevier GmbH. All rights reserved.

  11. Molecular-Level Transformations of Lignin During Photo-Oxidation and Biodegradation

    Science.gov (United States)

    Feng, X.; Hills, K.; Simpson, A. J.; Simpson, M. J.

    2009-05-01

    As the second most abundant component of terrestrial plant residues, lignin plays a key role in regulating plant litter decomposition, humic substance formation, and dissolved organic matter (OM) production from terrestrial sources. Biodegradation is the primary decomposition process of lignin on land. However, photo- oxidation of lignin-derived compounds has been reported in aquatic systems and is considered to play a vital role in arid and semiarid regions. With increasing ultraviolet (UV) radiation due to ozone depletion, it is important to understand the biogeochemical fate of lignin exposed to photo-oxidation in terrestrial environments. This study examines and compares the transformation of lignin in a three-month laboratory simulation of biodegradation and photo-oxidation using molecular-level techniques. Lignin-derived monomers extracted by copper oxidation were analyzed by gas chromatography/mass spectrometry (GC/MS) from the water-soluble and insoluble OM of 13C-labeled corn leaves. Biodegradation increased the solubility of lignin monomers in comparison to the control samples, and the acid-to-aldehyde (Ad/Al) ratios increased in both the water-soluble and insoluble OM, indicating a higher degree of side-chain lignin oxidation. Photo-oxidation did not produce a significant change on the solubility or Ad/Al ratios of lignin from corn leaves. However, the ratios of trans-to-cis isomers of both cinnamyl units (p-coumaric acid and ferulic acid) increased with photo-oxidation and decreased with biodegradation in the insoluble OM. We also investigated the role of photo-oxidation in lignin transformation in soils cropped with 13C-labeled corn. Interestingly, the organic carbon content increased significantly with time in the water-soluble OM from soil/corn residues under UV radiation. An increase in the concentration of lignin monomers and dimers and the Ad/Al ratios was also observed with photo-oxidation. Iso-branched fatty acids of microbial origin remained in

  12. Transcriptional profiling at whole population and single cell levels reveals somatosensory neuron molecular diversity

    Science.gov (United States)

    Chiu, Isaac M; Barrett, Lee B; Williams, Erika K; Strochlic, David E; Lee, Seungkyu; Weyer, Andy D; Lou, Shan; Bryman, Gregory S; Roberson, David P; Ghasemlou, Nader; Piccoli, Cara; Ahat, Ezgi; Wang, Victor; Cobos, Enrique J; Stucky, Cheryl L; Ma, Qiufu; Liberles, Stephen D; Woolf, Clifford J

    2014-01-01

    The somatosensory nervous system is critical for the organism's ability to respond to mechanical, thermal, and nociceptive stimuli. Somatosensory neurons are functionally and anatomically diverse but their molecular profiles are not well-defined. Here, we used transcriptional profiling to analyze the detailed molecular signatures of dorsal root ganglion (DRG) sensory neurons. We used two mouse reporter lines and surface IB4 labeling to purify three major non-overlapping classes of neurons: 1) IB4+SNS-Cre/TdTomato+, 2) IB4−SNS-Cre/TdTomato+, and 3) Parv-Cre/TdTomato+ cells, encompassing the majority of nociceptive, pruriceptive, and proprioceptive neurons. These neurons displayed distinct expression patterns of ion channels, transcription factors, and GPCRs. Highly parallel qRT-PCR analysis of 334 single neurons selected by membership of the three populations demonstrated further diversity, with unbiased clustering analysis identifying six distinct subgroups. These data significantly increase our knowledge of the molecular identities of known DRG populations and uncover potentially novel subsets, revealing the complexity and diversity of those neurons underlying somatosensation. DOI: http://dx.doi.org/10.7554/eLife.04660.001 PMID:25525749

  13. Global plant-responding mechanisms to salt stress: physiological and molecular levels and implications in biotechnology.

    Science.gov (United States)

    Tang, Xiaoli; Mu, Xingmin; Shao, Hongbo; Wang, Hongyan; Brestic, Marian

    2015-01-01

    The increasing seriousness of salinization aggravates the food, population and environmental issues. Ameliorating the salt-resistance of plants especially the crops is the most effective measure to solve the worldwide problem. The salinity can cause damage to plants mainly from two aspects: hyperosmotic and hyperionic stresses leading to the restrain of growth and photosynthesis. To the adverse effects, the plants derive corresponding strategies including: ion regulation and compartmentalization, biosynthesis of compatible solutes, induction of antioxidant enzymes and plant hormones. With the development of molecular biology, our understanding of the molecular and physiology knowledge is becoming clearness. The complex signal transduction underlying the salt resistance is being illuminated brighter and clearer. The SOS pathway is the central of the cell signaling in salt stress. The accumulation of the compatible solutes and the activation of the antioxidant system are the effective measures for plants to enhance the salt resistance. How to make full use of our understanding to improve the output of crops is a huge challenge for us, yet the application of the genetic engineering makes this possible. In this review, we will discuss the influence of the salt stress and the response of the plants in detail expecting to provide a particular account for the plant resistance in molecular, physiological and transgenic fields.

  14. Molecular dynamics simulations of ejecta production from sinusoidal tin surfaces under supported and unsupported shocks

    Science.gov (United States)

    Wu, Bao; Wu, FengChao; Zhu, YinBo; Wang, Pei; He, AnMin; Wu, HengAn

    2018-04-01

    Micro-ejecta, an instability growth process, occurs at metal/vacuum or metal/gas interface when compressed shock wave releases from the free surface that contains surface defects. We present molecular dynamics (MD) simulations to investigate the ejecta production from tin surface shocked by supported and unsupported waves with pressures ranging from 8.5 to 60.8 GPa. It is found that the loading waveforms have little effect on spike velocity while remarkably affect the bubble velocity. The bubble velocity of unsupported shock loading remains nonzero constant value at late time as observed in experiments. Besides, the time evolution of ejected mass in the simulations is compared with the recently developed ejecta source model, indicating the suppressed ejection of unmelted or partial melted materials. Moreover, different reference positions are chosen to characterize the amount of ejecta under different loading waveforms. Compared with supported shock case, the ejected mass of unsupported shock case saturates at lower pressure. Through the analysis on unloading path, we find that the temperature of tin sample increases quickly from tensile stress state to zero pressure state, resulting in the melting of bulk tin under decaying shock. Thus, the unsupported wave loading exhibits a lower threshold pressure causing the solid-liquid phase transition on shock release than the supported shock loading.

  15. Source-sink interaction: a century old concept under the light of modern molecular systems biology.

    Science.gov (United States)

    Chang, Tian-Gen; Zhu, Xin-Guang; Raines, Christine

    2017-07-20

    Many approaches to engineer source strength have been proposed to enhance crop yield potential. However, a well-co-ordinated source-sink relationship is required finally to realize the promised increase in crop yield potential in the farmer's field. Source-sink interaction has been intensively studied for decades, and a vast amount of knowledge about the interaction in different crops and under different environments has been accumulated. In this review, we first introduce the basic concepts of source, sink and their interactions, then summarize current understanding of how source and sink can be manipulated through both environmental control and genetic manipulations. We show that the source-sink interaction underlies the diverse responses of crops to the same perturbations and argue that development of a molecular systems model of source-sink interaction is required towards a rational manipulation of the source-sink relationship for increased yield. We finally discuss both bottom-up and top-down routes to develop such a model and emphasize that a community effort is needed for development of this model. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  16. Molecular systems under shock compression into the dense plasma regime: carbon dioxide and hydrocarbon polymers

    Science.gov (United States)

    Mattsson, Thomas R.; Cochrane, Kyle R.; Root, Seth; Carpenter, John H.

    2013-10-01

    Density Functional Theory (DFT) has proven remarkably accurate in predicting properties of matter under shock compression into the dense plasma regime. Materials where chemistry plays a role are of interest for many applications, including planetary science and inertial confinement fusion (ICF). As examples of systems where chemical reactions are important, and demonstration of the high fidelity possible for these both structurally and chemically complex systems, we will discuss shock- and re-shock of liquid carbon dioxide (CO2) in the range 100 to 800 GPa and shock compression of hydrocarbon polymers, including GDP (glow discharge polymer) which is used as an ablator in laser ICF experiments. Experimental results from Sandia's Z machine validate the DFT simulations at extreme conditions and the combination of experiment and DFT provide reliable data for evaluating existing and constructing future wide-range equations of state models for molecular compounds. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  17. A comparison of nitrate level in spinach grown both under different densities in aquaponic system and under natural growth conditions

    Directory of Open Access Journals (Sweden)

    Ştefan Mihai PETREA

    2013-12-01

    Full Text Available As bio-integrated systems that link both plants and fish culture, inside aquaponic systems, the processes of ammonia-oxidizing and nitrification in nitrite and nitrate are essential for growth and development of both fish and plants culture biomass. Plants with nearly the same nutritional requirements during their life cycle, like spinach in our case, are recommended to be grown under aquaponic conditions. Although nitrates concentrations up to 200 – 250mg/l are reported to be acceptable for fish growth, in the last years the toxic effect of long term exposure to high nitrate levels on fish and plants cultured biomass were highlighted. The main goal of the present study is to compare the nitrate level of spinach, grown in an aquaponic system, under three plant densities (V1 - 59 plants/m2, V2 - 48plants/m2 and V3 – 39 plants/m2. The second objective is to compare the results obtained, in term of nitrate content, for spinach grown in the integrated rainbow trout – spinach aquaponic system with those of marketable spinach, grown under conventional condition, in the field. The experimental design consists in a recirculating aquaculture system with 12 growing units, mechanical and biological water treatment units and four aquaponic units. Fish were fed with two types of feed with 41% and 50% protein, using 3 different feeding regimes. The results show a higher nitrate level on spinach grown in aquaponic system, compared to the one derived from field culture. Differences were observed also among the three variants grown in aquaponic conditions, under different plant densities. As a conclusion, it can be said that considering the nitrate level, spinach grown in aquaponic system is marketable.

  18. Molecular level investigation of CH4 and CO2 adsorption in hydrated Ca-Montmorillonite

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Mal Soon; McGrail, Bernard P.; Rousseau, Roger J.; Glezakou, Vassiliki-Alexandra

    2018-01-18

    We have studied the mechanism of intercalation and methane adsorption from a H2O/CH4/CO2 mixture on a prototypical shale component, Ca-montmorillonite. We employed ab initio molecular dynamics simulations at 323 K and 90 bar to obtain molecular level information of adsorption energetics, speciation, and structural and thermodynamic properties. Interaction of CH4 with surface Lewis acidic sites (Ca2+, surface OH) results in large induced dipoles (~1 D) that lead to relatively strong adsorption energies that level off once a full CH4 layer is formed. Intercalated CH4, also exhibits induced dipoles at low hydration levels, when the interaction with Ca2+ cations are less hindered. CO2 displaces CH4 in the coordination sphere of the cations (in the interlayer) or in the surface, thereby driving CH4 extraction. Our simulations indicate that there is a Goldilocks pressure range (~60-100 bar) where scCO2 –facilitated CH4 extraction will be maximized.

  19. Low-Volatility Model Demonstrates Humidity Affects Environmental Toxin Deposition on Plastics at a Molecular Level.

    Science.gov (United States)

    Hankett, Jeanne M; Collin, William R; Yang, Pei; Chen, Zhan; Duhaime, Melissa

    2016-02-02

    Despite the ever-increasing prevalence of plastic debris and endocrine disrupting toxins in aquatic ecosystems, few studies describe their interactions in freshwater environments. We present a model system to investigate the deposition/desorption behaviors of low-volatility lake ecosystem toxins on microplastics in situ and in real time. Molecular interactions of gas-phase nonylphenols (NPs) with the surfaces of two common plastics, poly(styrene) and poly(ethylene terephthalate), were studied using quartz crystal microbalance and sum frequency generation vibrational spectroscopy. NP point sources were generated under two model environments: plastic on land and plastic on a freshwater surface. We found the headspace above calm water provides an excellent environment for NP deposition and demonstrate significant NP deposition on plastic within minutes at relevant concentrations. Further, NP deposits and orders differently on both plastics under humid versus dry environments. We attributed the unique deposition behaviors to surface energy changes from increased water content during the humid deposition. Lastly, nanograms of NP remained on microplastic surfaces hours after initial NP introduction and agitating conditions, illustrating feasibility for plastic-bound NPs to interact with biota and surrounding matter. Our model studies reveal important interactions between low-volatility environmental toxins and microplastics and hold potential to correlate the environmental fate of endocrine disrupting toxins in the Great Lakes with molecular behaviors.

  20. Assessment of molecular events during in vitro re-epithelialization under honey-alginate matrix ambience

    International Nuclear Information System (INIS)

    Barui, Ananya; Mandal, Naresh; Majumder, Subhadipa; Das, Raunak Kumar; Sengupta, Sanghamitra; Banerjee, Provas; Ray, Ajoy Kumar; RoyChaudhuri, Chirosree; Chatterjee, Jyotirmoy

    2013-01-01

    Re-epithelialization is one of the most important stages of cutaneous regeneration and its success requires supportive micro-ambience which may be provided with suitable bio-matrix. Biocompatibility and efficacy of such bio-matrix in re-epithelialization could be explored by multimodal analysis of structural and functional attributes of in vitro wound healing model including evaluation of prime molecular expressions of the epithelial cells during repair. Present study examines the influence of honey-alginate and alginate matrices on re-epithelialization in keratinocyte (HaCaT) population in a 2-D wound model. Cellular viability, proliferation and cell–cell adhesion status were assessed during wound closure using live/dead cell assay and by evaluating expressions of Ki67, p63 and E-cadherin along-with % change in cellular electrical impedance. Efficacy of honey-alginate matrix in comparison to only alginate one was demonstrated by a quicker reduction in wound gap, improved cellular viability, enhanced expressions of Ki67, p63 and its isoforms (TAp63, ΔNp63) as well as E-cadherin. Faster restoration of electrical attribute (% of impedance change) after wounding also indicated better impact of honey-alginate matrix in re-epithelialization. - Highlights: • Role of honey based matrix is evaluated in wound re-epithelialization. • Healing impact of matrix studied in 2D in vitro keratinocyte (HaCaT) wound model. • Faster impedance restoration indicated rapid healing rate of HaCaT under honey. • PCR observations showed faster initiation of cell proliferation under honey. • ICC study indicated better up-regulation of healing markers under honey matrix

  1. Unraveling the effect of the hydration level on the molecular mobility of nanolayered polymeric systems.

    Science.gov (United States)

    Borges, João; Caridade, Sofia G; Silva, Joana M; Mano, João F

    2015-02-01

    This work investigates the influence of the hydration level on the molecular mobility and glass transition dynamics of freestanding chitosan/alginate (CHT/ALG) nanolayered systems. Nonconventional dynamic mechanical analysis identifies two relaxation processes assigned to the α-relaxation of the two biopolymers, respectively, CHT and ALG, when immersed in water/ethanol mixtures. This phenomenon explains the shape memory properties of the multilayered systems induced by hydration, thus constituting promising smart materials that would be of paramount importance in a plethora of research fields, including in the biomedical and biotechnological fields. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Investigation of the molecular level interactions between mucins and food proteins: Spectroscopic, tribological and rheological studies

    DEFF Research Database (Denmark)

    Celebioglu, Hilal Yilmaz

    The thesis investigated the structure and molecular-level interaction of β-lactoglobulin (BLG) and mucins, representing major components of the dairy products and saliva/digestion systems, respectively. Mucins are long glycoprotein molecules responsible for the gel nature of the mucous layer covers...... submaxillary mucin (BSM), a major salivary protein, were studied using high and low field Nuclear Magnetic Resonance (NMR), Dynamic Light Scattering (DLS), and Circular Dichroism (CD) spectroscopy. The zeta potentials of the proteins were also measured to provide information on the role of electrostatic forces...

  3. Molecular analyses reveal high levels of eukaryotic richness associated with enigmatic deep-sea protists (Komokiacea)

    DEFF Research Database (Denmark)

    Lecroq, Beatrice; Gooday, Andrew John; Cedhagen, Tomas

    2009-01-01

    morphological features. To examine their taxonomic position at the molecular level, we analysed the SSU rDNA sequences of two species, Normanina conferta and Septuma ocotillo, obtained either with specific foraminiferal or universal eukaryotic primers. Many different sequences resulted from this investigation...... but none of them could clearly be attributed to komokiaceans. Although our study failed to confirm univocally that Komokiacea are foraminiferans, it revealed a huge eukaryotic richness associated with these organisms, comparable with the richness in the overall surrounding sediment. These observations...

  4. Molecular enzymology underlying regulation of protein phosphatase-1 by natural toxins.

    Science.gov (United States)

    Holmes, C F B; Maynes, J T; Perreault, K R; Dawson, J F; James, M N G

    2002-11-01

    The protein serine/threonine phosphatases constitute a unique class of enzymes that are critical for cell regulation, as they must counteract the activities of thousands of protein kinases in human cells. Uncontrolled inhibition of phosphatase activity by toxic inhibitors can lead to widespread catastrophic effects. Over the past decade, a number of natural product toxins have been identified that specifically and potently inhibit protein phosphatase-1 and 2A. Amongst these are the cyanobacteria-derived cyclic heptapeptide microcystin-LR and the polyether fatty acid okadaic acid from dinoflagellate sources. The molecular mechanism underlying potent inhibition of protein phosphatase-1 by these toxins is becoming clear through insights gathered from diverse sources. These include: 1. Comparison of structure-activity relationships amongst the different classes of toxins. 2. Delineation of the structural differences between protein phosphatase-1 and 2A that account for their differing sensitivity to toxins, particularly okadaic acid and microcystin-LR. 3. Determination of the crystal structure of protein phosphatase-1 with microcystin-LR, okadaic acid and calyculin bound. 4. Site-specific mutagenesis and biochemical analysis of protein phosphatase-1 mutants. Taken together, these data point to a common binding site on protein phosphatase-1 for okadaic acid, microcystin-LR and the calyculins. However, careful analysis of these data suggest that each toxin binds to the common binding site in a subtly different way, relying on distinct structural interactions such as hydrophobic binding, hydrogen bonding and electrostatic interactions to different degrees. The insights derived from studying the molecular enzymology of protein phosphatase-1 may help explain the different sensitivities of other structurally conserved protein serine/theonine phosphatases to toxin inhibition. Furthermore, studies on the binding of structurally diverse toxins at the active site of protein

  5. Short-term dynamics of North Sea bacterioplankton-dissolved organic matter coherence on molecular level

    Directory of Open Access Journals (Sweden)

    Judith eLucas

    2016-03-01

    Full Text Available Remineralisation and transformation of dissolved organic matter (DOM by marine microbes shape the DOM composition and thus, have large impact on global carbon and nutrient cycling. However, information on bacterioplankton-DOM interactions on a molecular level is limited. We examined the variation of bacterial community composition at Helgoland Roads (North Sea in relation to variation of molecular DOM composition and various environmental parameters on short-time scales. Surface water samples were taken daily over a period of twenty days. Bacterial community and molecular DOM composition were assessed via 16S rRNA gene tag sequencing and ultrahigh resolution Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS, respectively. Environmental conditions were driven by a coastal water influx during the first half of the sampling period and the onset of a summer phytoplankton bloom towards the end of the sampling period. These phenomena led to a distinct grouping of bacterial communities and DOM composition which was particularly influenced by total dissolved nitrogen concentration, temperature and salinity, as revealed by distance-based linear regression analyses. Bacterioplankton-DOM interaction was demonstrated in strong correlations between specific bacterial taxa and particular DOM molecules, thus, suggesting potential specialization on particular substrates. We propose that a combination of high resolution techniques, as used in this study, may provide substantial information on substrate generalists and specialists and thus, contribute to prediction of bacterial community composition variation.

  6. Short-Term Dynamics of North Sea Bacterioplankton-Dissolved Organic Matter Coherence on Molecular Level.

    Science.gov (United States)

    Lucas, Judith; Koester, Irina; Wichels, Antje; Niggemann, Jutta; Dittmar, Thorsten; Callies, Ulrich; Wiltshire, Karen H; Gerdts, Gunnar

    2016-01-01

    Remineralization and transformation of dissolved organic matter (DOM) by marine microbes shape the DOM composition and thus, have large impact on global carbon and nutrient cycling. However, information on bacterioplankton-DOM interactions on a molecular level is limited. We examined the variation of bacterial community composition (BCC) at Helgoland Roads (North Sea) in relation to variation of molecular DOM composition and various environmental parameters on short-time scales. Surface water samples were taken daily over a period of 20 days. Bacterial community and molecular DOM composition were assessed via 16S rRNA gene tag sequencing and ultrahigh resolution Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), respectively. Environmental conditions were driven by a coastal water influx during the first half of the sampling period and the onset of a summer phytoplankton bloom toward the end of the sampling period. These phenomena led to a distinct grouping of bacterial communities and DOM composition which was particularly influenced by total dissolved nitrogen (TDN) concentration, temperature, and salinity, as revealed by distance-based linear regression analyses. Bacterioplankton-DOM interaction was demonstrated in strong correlations between specific bacterial taxa and particular DOM molecules, thus, suggesting potential specialization on particular substrates. We propose that a combination of high resolution techniques, as used in this study, may provide substantial information on substrate generalists and specialists and thus, contribute to prediction of BCC variation.

  7. Performance Evaluation of Three-Level Z-Source Inverters Under Semiconductor-Failure Conditions

    DEFF Research Database (Denmark)

    Gao, Feng; Loh, Poh Chiang; Blaabjerg, Frede

    2009-01-01

    This paper evaluates and proposes various compensation methods for three-level Z-source inverters under semiconductor-failure conditions. Unlike the fault-tolerant techniques used in traditional three-level inverters, where either an extra phase-leg or collective switching states are used...... under semiconductor-failure conditions. For verifying these described performance features, PLECS simulation and experimental testing were performed with some results captured and shown in a later section for visual confirmation....

  8. Rovibrational coupling in molecular nitrogen at high temperature: An atomic-level study

    International Nuclear Information System (INIS)

    Valentini, Paolo; Norman, Paul; Zhang, Chonglin; Schwartzentruber, Thomas E.

    2014-01-01

    This article contains an atomic-level numerical investigation of rovibrational relaxation in molecular nitrogen at high temperature (>4000 K), neglecting dissociation. We conduct our study with the use of pure Molecular Dynamics (MD) and Classical Trajectory Calculations (CTC) Direct Simulation Monte Carlo (DSMC), verified to produce statistically identical results at the conditions of interest here. MD and CTC DSMC solely rely on the specification of a potential energy surface: in this work, the site-site Ling-Rigby potential. Additionally, dissociation is prevented by modeling the N–N bond either as a harmonic or an anharmonic spring. The selected molecular model was shown to (i) recover the shear viscosity (obtained from equilibrium pure MD Green-Kubo calculations) of molecular nitrogen over a wide range of temperatures, up to dissociation; (ii) predict well the near-equilibrium rotational relaxation behavior of N 2 ; (iii) reproduce vibrational relaxation times in excellent accordance with the Millikan-White correlation and previous semi-classical trajectory calculations in the low temperature range, i.e., between 4000 K and 10 000 K. By simulating isothermal relaxations in a periodic box, we found that the traditional two-temperature model assumptions become invalid at high temperatures (>10 000 K), due to a significant coupling between rotational and vibrational modes for bound states. This led us to add a modification to both the Jeans and the Landau-Teller equations to include a coupling term, essentially described by an additional relaxation time for internal energy equilibration. The degree of anharmonicity of the N 2 bond determines the strength of the rovibrational coupling. Although neglecting N 2 dissociation only provides a partial description of a nitrogen system at very high temperatures, high-energy trends for bound-bound transitions are essential to understand nonequilibrium gas flows, with possible implications on rovibration

  9. Differential expression of EWI-2 in endometriosis, its functional role and underlying molecular mechanisms.

    Science.gov (United States)

    Zheng, Tingting; Yang, Jing

    2017-07-01

    We aimed to investigate EWI-2 expression in endometrium tissues collected from women with endometriosis at mRNA and protein levels, to evaluate its potential as a biomarker for endometriosis and to study its functional role via possible regulation of the PI3K/Akt signaling pathway. Endometrium tissues were collected from patients with endometriosis and healthy individuals. EWI-2 mRNA expression was evaluated using quantitative real-time PCR (qRT-PCR) while EWI-2 protein levels were determined by western blotting. For functional studies, EWI-2 shRNA was transfected in endometrial epithelial cells and the in vitro migration and invasion assays were performed using the Transwell chambers. EWI-2 was significantly downregulated in tissues obtained from patients with endometriosis compared with healthy individuals (P endometriosis diagnosis was 0.8942 (P = 0.003), 0.9643 (P = 0.0001), 0.9912 (P endometriosis in matched comparisons of data originated from the proliferative, early, middle, and late secretory phases. Over the menstrual cycle, the expression of EWI-2 was significantly decreased in the eutopic tissues compared to the ectopic tissues. Further cellular and molecular analyses showed that EWI-2 inhibited cell migration and invasion via the Akt signaling. Our findings suggested that downregulation of EWI-2 may contribute to endometriosis physiopathology and potentiate EWI-2 as a valuable diagnostic biomarker and therapeutic target for endometriosis. © 2017 Japan Society of Obstetrics and Gynecology.

  10. Assessing Flood Risk Under Sea Level Rise and Extreme Sea Levels Scenarios: Application to the Ebro Delta (Spain)

    Science.gov (United States)

    Sayol, J. M.; Marcos, M.

    2018-02-01

    This study presents a novel methodology to estimate the impact of local sea level rise and extreme surges and waves in coastal areas under climate change scenarios. The methodology is applied to the Ebro Delta, a valuable and vulnerable low-lying wetland located in the northwestern Mediterranean Sea. Projections of local sea level accounting for all contributions to mean sea level changes, including thermal expansion, dynamic changes, fresh water addition and glacial isostatic adjustment, have been obtained from regionalized sea level projections during the 21st century. Particular attention has been paid to the uncertainties, which have been derived from the spread of the multi-model ensemble combined with seasonal/inter-annual sea level variability from local tide gauge observations. Besides vertical land movements have also been integrated to estimate local relative sea level rise. On the other hand, regional projections over the Mediterranean basin of storm surges and wind-waves have been used to evaluate changes in extreme events. The compound effects of surges and extreme waves have been quantified using their joint probability distributions. Finally, offshore sea level projections from extreme events superimposed to mean sea level have been propagated onto a high resolution digital elevation model of the study region in order to construct flood hazards maps for mid and end of the 21st century and under two different climate change scenarios. The effect of each contribution has been evaluated in terms of percentage of the area exposed to coastal hazards, which will help to design more efficient protection and adaptation measures.

  11. Training with mild anxiety may prevent choking under higher levels of anxiety

    NARCIS (Netherlands)

    Oudejans, R.R.D.; Pijpers, J.R.

    2010-01-01

    Objective: The aim of the study was to examine whether training with mild levels of anxiety helps in maintaining performance under higher levels of anxiety. Methods: Novices practiced dart throwing while they were hanging low on a climbing wall either with or without mild anxiety. After training,

  12. Performance Evaluation of Three-Level Z-Source Inverters Under Semiconductor Failure Conditions

    DEFF Research Database (Denmark)

    Gao, Feng; Loh, P.C.; Vilathgamuwa, D.M.

    2007-01-01

    This paper proposes various compensation methods for three-level Z-source inverters under semiconductor failure conditions. Unlike the traditional fault tolerant techniques in three-level inverter by using either an additional phase-leg or collective switching states, the proposed methods simply ...

  13. Molecular-level architectural design using benzothiadiazole-based polymers for photovoltaic applications.

    Science.gov (United States)

    Viswanathan, Vinila N; Rao, Arun D; Pandey, Upendra K; Kesavan, Arul Varman; Ramamurthy, Praveen C

    2017-01-01

    A series of low band gap, planar conjugated polymers, P1 (PFDTBT), P2 (PFDTDFBT) and P3 (PFDTTBT), based on fluorene and benzothiadiazole, was synthesized. The effect of fluorine substitution and fused aromatic spacers on the optoelectronic and photovoltaic performance was studied. The polymer, derived from dithienylated benzothiodiazole and fluorene, P1 , exhibited a highest occupied molecular orbital (HOMO) energy level at -5.48 eV. Density functional theory (DFT) studies as well as experimental measurements suggested that upon substitution of the acceptor with fluorine, both the HOMO and lowest unoccupied molecular orbital (LUMO) energy levels of the resulting polymer, P2 , were lowered, leading to a higher open circuit voltage and short circuit current with an overall improvement of more than 110% for the photovoltaic devices. Moreover, a decrease in the torsion angle between the units was also observed for the fluorinated polymer P2 due to the enhanced electrostatic interaction between the fluorine substituents and sulfur atoms, leading to a high hole mobility. The use of a fused π-bridge in polymer P3 for the enhancement of the planarity as compared to the P1 backbone was also studied. This enhanced planarity led to the highest observed mobility among the reported three polymers as well as to an improvement in the device efficiency by more than 40% for P3 .

  14. Transcriptional Regulation of Aluminum-Tolerance Genes in Higher Plants: Clarifying the Underlying Molecular Mechanisms

    Directory of Open Access Journals (Sweden)

    Abhijit A. Daspute

    2017-08-01

    Full Text Available Aluminum (Al rhizotoxicity is one of the major environmental stresses that decrease global food production. Clarifying the molecular mechanisms underlying Al tolerance may contribute to the breeding of Al-tolerant crops. Recent studies identified various Al-tolerance genes. The expression of these genes is inducible by Al. Studies of the major Arabidopsis thaliana Al-tolerance gene, ARABIDOPSIS THALIANA ALUMINUM-ACTIVATED MALATE TRANSPORTER 1 (AtALMT1, which encodes an Al-activated malate transporter, revealed that the Al-inducible expression is regulated by a SENSITIVE TO PROTON RHIXOTOXICITY 1 (STOP1 zinc-finger transcription factor. This system, which involves STOP1 and organic acid transporters, is conserved in diverse plant species. The expression of AtALMT1 is also upregulated by several phytohormones and hydrogen peroxide, suggesting there is crosstalk among the signals involved in the transcriptional regulation of AtALMT1. Additionally, phytohormones and reactive oxygen species (ROS activate various transcriptional responses, including the expression of genes related to increased Al tolerance or the suppression of root growth under Al stress conditions. For example, Al suppressed root growth due to abnormal accumulation of auxin and cytokinin. It activates transcription of TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS 1 and other phytohormone responsive genes in distal transition zone, which causes suppression of root elongation. On the other hand, overexpression of Al inducible genes for ROS-detoxifying enzymes such as GLUTATHIONE–S-TRANSFERASE, PEROXIDASE, SUPEROXIDE DISMUTASE enhances Al resistance in several plant species. We herein summarize the complex transcriptional regulation of an Al-inducible genes affected by STOP1, phytohormones, and ROS.

  15. Molecular mechanisms underlying memory consolidation of taste information in the cortex

    Directory of Open Access Journals (Sweden)

    Shunit eGal-Ben-Ari

    2012-01-01

    Full Text Available The senses of taste and odor are both chemical senses. However, whereas an organism can detect an odor at a relatively long distance from its source, taste serves as the ultimate proximate gatekeeper of food intake: it helps in avoiding poisons and consuming beneficial substances. The automatic reaction to a given taste has been developed during evolution and is well adapted to conditions that may occur with high probability during the lifetime of an organism. However, in addition to this automatic reaction, animals can learn and remember tastes, together with their positive or negative values, with high precision and in light of minimal experience. This ability of mammalians to learn and remember tastes has been studied extensively in rodents through application of reasonably simple and well defined behavioral paradigms. The learning process follows a temporal continuum similar to those of other memories: acquisition, consolidation, retrieval, relearning, and reconsolidation. Moreover, inhibiting protein synthesis in the gustatory cortex specifically affects the consolidation phase of taste memory, i.e., the transformation of short- to long-term memory, in keeping with the general biochemical definition of memory consolidation. This review aims to present a general background of taste learning, and to focus on recent findings regarding the molecular mechanisms underlying taste memory consolidation in the gustatory cortex. Specifically, the role of neurotransmitters, meuromodulators, immediate early genes, and translation regulation are addressed.

  16. Studies of Neuronal Gene Regulation Controlling the Molecular Mechanisms Underlying Neural Plasticity.

    Science.gov (United States)

    Fukuchi, Mamoru

    2017-01-01

    The regulation of the development and function of the nervous system is not preprogramed but responds to environmental stimuli to change neural development and function flexibly. This neural plasticity is a characteristic property of the nervous system. For example, strong synaptic activation evoked by environmental stimuli leads to changes in synaptic functions (known as synaptic plasticity). Long-lasting synaptic plasticity is one of the molecular mechanisms underlying long-term learning and memory. Since discovering the role of the transcription factor cAMP-response element-binding protein in learning and memory, it has been widely accepted that gene regulation in neurons contributes to long-lasting changes in neural functions. However, it remains unclear how synaptic activation is converted into gene regulation that results in long-lasting neural functions like long-term memory. We continue to address this question. This review introduces our recent findings on the gene regulation of brain-derived neurotrophic factor and discusses how regulation of the gene participates in long-lasting changes in neural functions.

  17. Atomistic simulations of highly conductive molecular transport junctions under realistic conditions

    KAUST Repository

    French, William R.

    2013-01-01

    We report state-of-the-art atomistic simulations combined with high-fidelity conductance calculations to probe structure-conductance relationships in Au-benzenedithiolate (BDT)-Au junctions under elongation. Our results demonstrate that large increases in conductance are associated with the formation of monatomic chains (MACs) of Au atoms directly connected to BDT. An analysis of the electronic structure of the simulated junctions reveals that enhancement in the s-like states in Au MACs causes the increases in conductance. Other structures also result in increased conductance but are too short-lived to be detected in experiment, while MACs remain stable for long simulation times. Examinations of thermally evolved junctions with and without MACs show negligible overlap between conductance histograms, indicating that the increase in conductance is related to this unique structural change and not thermal fluctuation. These results, which provide an excellent explanation for a recently observed anomalous experimental result [Bruot et al., Nat. Nanotechnol., 2012, 7, 35-40], should aid in the development of mechanically responsive molecular electronic devices. © 2013 The Royal Society of Chemistry.

  18. Stability of Newton black films under mechanical stretch--a molecular dynamics study.

    Science.gov (United States)

    Shen, Zhe; Sun, Huai; Liu, Xiaoyan; Liu, Wenting; Tang, Ming

    2013-09-10

    The stability of Newton black films (NBFs) under lateral mechanical stretch was investigated by nonequilibrium molecular dynamics (NEMD) simulations using force field parameters validated by accurate prediction of surface tensions. The applied strains accelerated film ruptures, enabling efficient measurements of the critical thicknesses of the films. Two representative surfactants, sodium dodecyl sulfate (SDS) for ionic surfactant and pentaethylene glycol monododecyl ether (C12EO5H) for nonionic surfactant, were investigated and compared. The predicted critical thickness of C12EO5H-coated film is smaller than that of the SDS-coated film, which is consistent with previously reported experimental observations. Our simulation results show that while the two surfactant-coated films exhibit similar dynamic properties attributed to the Marangoni-Gibbs effect, their surface structural characteristics are quite different. Consequently the two films demonstrate distinct rupture mechanisms in which rupture starts at uncovered water domains in the SDS-coated film, but at lateral surfactant/water interfaces in the C12EO5H-coated film. Our findings provide new insights into the stabilization mechanisms of NBFs and will facilitate the design and development of new films with improved properties.

  19. Response of maize ( Zea mays L.) to varied moisture levels under ...

    African Journals Online (AJOL)

    Laboratory and glasshouse trials were used to determine the response of maize plants to varied moisture levels under Striga lutea infestation. Six moisture levels (1.5, 2.0, 2.5, 3.0, 3.5 and 4.0 ml) were applied to striga seed for germination count in the laboratory, while five moisture levels (300, 600, 900, 1200 and 1500 ml) ...

  20. A theoretical study of bone remodelling under PEMF at cellular level.

    Science.gov (United States)

    Wang, Yanan; Qin, Qing-Hua

    2012-01-01

    Pulsed electromagnetic field (PEMF) devices have been used clinically to slow down osteoporosis and accelerate the healing of bone fractures for many years. However, the underlying mechanism by which bone remodelling under PEMF is regulated remains poorly understood. In this paper, a mathematical model of bone cell population of bone remodelling under PEMF at cellular level is developed to address this issue for the first time. On the basis of this model and control theory, parametric study of control mechanisms is carried out and a number of possible control mechanisms are identified. These findings will help further the understanding of bone remodelling under PEMF and advance therapies and pharmacological developments in clinical trials.

  1. Molecular decomposition of solid methane films and emission of molecular fragments under MeV ion bombardment

    International Nuclear Information System (INIS)

    Brown, W.L.; Lanzerotti, L.J.; Bower, J.E.; Marcantonio, K.J.

    1987-01-01

    Electronic and collisional excitation of thin films of condensed molecular gases (H 2 O, O 2 , N 2 , CO 2 , NH 3 , SO 2 , CH 4 , etc.) by MeV and keV ions results in sputtering of the primary molecules. In addition, new solid molecular species, formed from fragments of the original molecules, are also emittted. Solid methane is a particularly interesting case. Hydrogen is a principal emission product of methane as it is in the bombardment of all hydrocarbons. However, in methane electronically excited by MeV light ions, the major hydrogen release occurs only after a well defined threshold ion fluence. This suggests a percolation threshold for the escape of hydrogen: material modification of the solid methane must proceed to a point at which a continuous diffusion path of high diffusion coefficient exists to the surface from within the film before the major emission can take place. The threshold fluence depends on the excitation density along individual ion tracks in a non-linear way, higher stopping power ions being more ''efficient'' in reaching the threshold. Carbon is also lost from methane films but in a quantity which is a decreasing fraction in thicker films. (orig.)

  2. FAMILY’S ECONOMIC LEVEL AND CULTURE CORRELATE WITH NUTRITIONAL STATUS OF CHILDREN UNDER FIVE YEARS

    Directory of Open Access Journals (Sweden)

    Abdul Muhith

    2017-01-01

    Full Text Available Introduction: Nutrition is an important thing for human life. Variety in family’s economic level and culture have effect on family’s eating habit. Family with higher economic status have big opportunity to met under fi ve year’s nutrition. Cultural diversity on each family has an impact on the difference of raw food selection, processing methods, and presentation of food. The purpose of this study was to determine the correlation between family’s economic level and culture with nutritional status of children under fi ve year. Method: Research design was observational analytic with cross sectional approach. The population were mother and their children under fi ve years at Desa Jatigono Kunir, Kabupaten Lumajang. Sampel were 184 respondents, taken by using cluster sampling. Independent variables were family’s economic level and culture. Dependent variable was nutritional status of children under fi ve years. Data were collected by using questionnaire and observational sheet. Then, data were analyzed by using Spearman Rho Test with α<0.05. Result: The results showed that 140 (76.1% respondents have low economic level, 105 (57.1% respondents have negative culture in children’s nutrition, and 89 (48% respondents have good nutritional status. The result of Spearman-rho test showed that family’s economic level (p=0.000 and culture (0.019 have correlated with nutritional status of children under five years. Discussion: It can be concluded that family’s economic level and culture have correlated with nutritional status of children under fi ve years. Nurses should develop health education and counseling to improve family’s knowledge about nutrition, so children will have good nutritional status. Keywords: economic level, family’s culture, nutritional status, children under five years

  3. Molecular basis for the regulation of hypoxia-inducible factor-1α levels by 2-deoxy-D-ribose.

    Science.gov (United States)

    Ikeda, Ryuji; Tabata, Sho; Tajitsu, Yusuke; Nishizawa, Yukihiko; Minami, Kentaro; Furukawa, Tatsuhiko; Yamamoto, Masatatsu; Shinsato, Yoshinari; Akiyama, Shin-Ichi; Yamada, Katsushi; Takeda, Yasuo

    2013-09-01

    The angiogenic factor, platelet-derived endothelial cell growth factor/thymidine phosphorylase (PD-ECGF/TP), stimulates the chemotaxis of endothelial cells and confers resistance to apoptosis induced by hypoxia. 2-Deoxy-D-ribose, a degradation product of thymidine generated by TP enzymatic activity, inhibits the upregulation of hypoxia-inducible factor (HIF) 1α, BNIP3 and caspase-3 induced by hypoxia. In the present study, we investigated the molecular basis for the suppressive effect of 2-deoxy-D-ribose on the upregulation of HIF-1α. 2-Deoxy-D-ribose enhanced the interaction of HIF-1α and the von Hippel-Lindau (VHL) protein under hypoxic conditions. It did not affect the expression of HIF-1α, prolyl hydroxylase (PHD)1/2/3 and VHL mRNA under normoxic or hypoxic conditions, but enhanced the interaction of HIF-1α and PHD2 under hypoxic conditions. 2-Deoxy-D-ribose also increased the amount of hydroxy-HIF-1α in the presence of the proteasome inhibitor MG-132. The expression levels of TP are elevated in many types of malignant solid tumors and, thus, 2-deoxy-D-ribose generated by TP in these tumors may play an important role in tumor progression by preventing hypoxia-induced apoptosis.

  4. Water interactions with condensed organic phases: a combined experimental and theoretical study of molecular-level processes

    Science.gov (United States)

    Johansson, Sofia M.; Kong, Xiangrui; Thomson, Erik S.; Papagiannakopoulos, Panos; Pettersson, Jan B. C.; Lovrić, Josip; Toubin, Céline

    2016-04-01

    Water uptake on aerosol particles modifies their chemistry and microphysics with important implications for air quality and climate. A large fraction of the atmospheric aerosol consists of organic aerosol particles or inorganic particles with condensed organic components. Here, we combine laboratory studies using the environmental molecular beam (EMB) method1 with molecular dynamics (MD) simulations to characterize water interactions with organic surfaces in detail. The over-arching aim is to characterize the mechanisms that govern water uptake, in order to guide the development of physics-based models to be used in atmospheric modelling. The EMB method enables molecular level studies of interactions between gases and volatile surfaces at near ambient pressure,1 and the technique may provide information about collision dynamics, surface and bulk accommodation, desorption and diffusion kinetics. Molecular dynamics simulations provide complementary information about the collision dynamics and initial interactions between gas molecules and the condensed phase. Here, we focus on water interactions with condensed alcohol phases that serve as highly simplified proxies for systems in the environment. Gas-surface collisions are in general found to be highly inelastic and result in efficient surface accommodation of water molecules. As a consequence, surface accommodation of water can be safely assumed to be close to unity under typical ambient conditions. Bulk accommodation is inefficient on solid alcohol and the condensed materials appear to produce hydrophobic surface structures, with limited opportunities for adsorbed water to form hydrogen bonds with surface molecules. Accommodation is significantly more efficient on the dynamic liquid alcohol surfaces. The results for n-butanol (BuOH) are particularly intriguing where substantial changes in water accommodation taking place over a 10 K interval below and above the BuOH melting point.2 The governing mechanisms for the

  5. Identification of light absorbing oligomers from glyoxal and methylglyoxal aqueous processing: a comparative study at the molecular level

    Science.gov (United States)

    Finessi, Emanuela; Hamilton, Jacqueline; Rickard, Andrew; Baeza-Romero, Maria; Healy, Robert; Peppe, Salvatore; Adams, Tom; Daniels, Mark; Ball, Stephen; Goodall, Iain; Monks, Paul; Borras, Esther; Munoz, Amalia

    2014-05-01

    Numerous studies point to the reactive uptake of gaseous low molecular weight carbonyls onto atmospheric waters (clouds/fog droplets and wet aerosols) as an important SOA formation route not yet included in current models. However, the evaluation of these processes is challenging because water provides a medium for a complex array of reactions to take place such as self-oligomerization, aldol condensation and Maillard-type browning reactions in the presence of ammonium salts. In addition to adding to SOA mass, aqueous chemistry products have been shown to include light absorbing, surface-active and high molecular weight oligomeric species, and can therefore affect climatically relevant aerosol properties such as light absorption and hygroscopicity. Glyoxal (GLY) and methylglyoxal (MGLY) are the gaseous carbonyls that have perhaps received the most attention to date owing to their ubiquity, abundance and reactivity in water, with the majority of studies focussing on bulk physical properties. However, very little is known at the molecular level, in particular for MGLY, and the relative potential of these species as aqueous SOA precursors in ambient air is still unclear. We have conducted experiments with both laboratory solutions and chamber-generated particles to simulate the aqueous processing of GLY and MGLY with ammonium sulphate (AS) under typical atmospheric conditions and investigated their respective aging products. Both high performance liquid chromatography coupled with UV-Vis detection and ion trap mass spectrometry (HPLC-DAD-MSn) and high resolution mass spectrometry (FTICRMS) have been used for molecular identification purposes. Comprehensive gas chromatography with nitrogen chemiluminescence detection (GCxGC-NCD) has been applied for the first time to these systems, revealing a surprisingly high number of nitrogen-containing organics (ONs), with a large extent of polarities. GCxGC-NCD proved to be a valuable tool to determine overall amount and rates of

  6. Determination of trace levels of triazines in corn matrices by bar adsorptive microextraction with a molecularly imprinted polymer.

    Science.gov (United States)

    Andrade, Felipe Nascimento; Ide, Alessandra Honjo; Neng, Nuno da Rosa; Lanças, Fernando Mauro; Nogueira, José Manuel Florêncio

    2016-02-01

    This manuscript addresses the determination of triazines (ametryn, atrazine, simazine, and terbutryn) in corn matrices using bar adsorptive microextraction coated with a selective molecularly imprinted polymer phase following microliquid desorption and high-performance liquid chromatography with diode array detection. The molecularly imprinted polymer was synthesized using atrazine as a template and methacrylic acid as a functional monomer. Assays performed in 25 mL of ultrapure water samples spiked at 8.0 μg/L yielded 80-120 % recoveries under the evaluated experimental conditions. The method showed an accuracy (0.2 0.9926). The proposed analytical method was applied to monitor triazines in three types of corn matrices using the standard addition methodology. Experiments performed in corn samples spiked with triazines at the trace level (8.0 μg/kg of each analyte) gave rise to recoveries (81.0-119.4%) with good reproducibility and robustness. The proposed methodology is also easy to implement and showed to be a good analytical alternative to monitor triazines in complex matrices, when compared with other sorption-based microextraction techniques. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Allowances for evolving coastal flood risk under uncertain local sea-level rise

    Science.gov (United States)

    Buchanan, M. K.; Kopp, R. E.; Oppenheimer, M.; Tebaldi, C.

    2015-12-01

    Sea-level rise (SLR) causes estimates of flood risk made under the assumption of stationary mean sea level to be biased low. However, adjustments to flood return levels made assuming fixed increases of sea level are also inaccurate when applied to sea level that is rising over time at an uncertain rate. To accommodate both the temporal dynamics of SLR and their uncertainty, we develop an Average Annual Design Life Level (AADLL) metric and associated SLR allowances [1,2]. The AADLL is the flood level corresponding to a time-integrated annual expected probability of occurrence (AEP) under uncertainty over the lifetime of an asset; AADLL allowances are the adjustment from 2000 levels that maintain current risk. Given non-stationary and uncertain SLR, AADLL flood levels and allowances provide estimates of flood protection heights and offsets for different planning horizons and different levels of confidence in SLR projections in coastal areas. Allowances are a function primarily of local SLR and are nearly independent of AEP. Here we employ probabilistic SLR projections [3] to illustrate the calculation of AADLL flood levels and allowances with a representative set of long-duration tide gauges along U.S. coastlines. [1] Rootzen et al., 2014, Water Resources Research 49: 5964-5972. [2] Hunter, 2013, Ocean Engineering 71: 17-27. [3] Kopp et al., 2014, Earth's Future 2: 383-406.

  8. Deciphering the molecular mechanisms underlying sea urchin reversible adhesion: A quantitative proteomics approach.

    Science.gov (United States)

    Lebesgue, Nicolas; da Costa, Gonçalo; Ribeiro, Raquel Mesquita; Ribeiro-Silva, Cristina; Martins, Gabriel G; Matranga, Valeria; Scholten, Arjen; Cordeiro, Carlos; Heck, Albert J R; Santos, Romana

    2016-04-14

    Marine bioadhesives have unmatched performances in wet environments, being an inspiration for biomedical applications. In sea urchins specialized adhesive organs, tube feet, mediate reversible adhesion, being composed by a disc, producing adhesive and de-adhesive secretions, and a motile stem. After tube foot detachment, the secreted adhesive remains bound to the substratum as a footprint. Sea urchin adhesive is composed by proteins and sugars, but so far only one protein, Nectin, was shown to be over-expressed as a transcript in tube feet discs, suggesting its involvement in sea urchin adhesion. Here we use high-resolution quantitative mass-spectrometry to perform the first study combining the analysis of the differential proteome of an adhesive organ, with the proteome of its secreted adhesive. This strategy allowed us to identify 163 highly over-expressed disc proteins, specifically involved in sea urchin reversible adhesion; to find that 70% of the secreted adhesive components fall within five protein groups, involved in exocytosis and microbial protection; and to provide evidences that Nectin is not only highly expressed in tube feet discs but is an actual component of the adhesive. These results give an unprecedented insight into the molecular mechanisms underlying sea urchin adhesion, and opening new doors to develop wet-reliable, reversible, and ecological biomimetic adhesives. Sea urchins attach strongly but in a reversible manner to substratum, being a valuable source of inspiration for industrial and biomedical applications. Yet, the molecular mechanisms governing reversible adhesion are still poorly studied delaying the engineering of biomimetic adhesives. We used the latest mass spectrometry techniques to analyze the differential proteome of an adhesive organ and the proteome of its secreted adhesive, allowing us to uncover the key players in sea urchin reversible adhesion. We demonstrate, that Nectin, a protein previously pointed out as potentially

  9. Initial decomposition of the condensed-phase β-HMX under shock waves: molecular dynamics simulations.

    Science.gov (United States)

    Ge, Ni-Na; Wei, Yong-Kai; Ji, Guang-Fu; Chen, Xiang-Rong; Zhao, Feng; Wei, Dong-Qing

    2012-11-26

    We have performed quantum-based multiscale simulations to study the initial chemical processes of condensed-phase octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) under shock wave loading. A self-consistent charge density-functional tight-binding (SCC-DFTB) method was employed. The results show that the initial decomposition of shocked HMX is triggered by the N-NO(2) bond breaking under the low velocity impact (8 km/s). As the shock velocity increases (11 km/s), the homolytic cleavage of the N-NO(2) bond is suppressed under high pressure, the C-H bond dissociation becomes the primary pathway for HMX decomposition in its early stages. It is accompanied by a five-membered ring formation and hydrogen transfer from the CH(2) group to the -NO(2) group. Our simulations suggest that the initial chemical processes of shocked HMX are dependent on the impact velocity, which gain new insights into the initial decomposition mechanism of HMX upon shock loading at the atomistic level, and have important implications for understanding and development of energetic materials.

  10. Molecular phenology in plants: in natura systems biology for the comprehensive understanding of seasonal responses under natural environments.

    Science.gov (United States)

    Kudoh, Hiroshi

    2016-04-01

    Phenology refers to the study of seasonal schedules of organisms. Molecular phenology is defined here as the study of the seasonal patterns of organisms captured by molecular biology techniques. The history of molecular phenology is reviewed briefly in relation to advances in the quantification technology of gene expression. High-resolution molecular phenology (HMP) data have enabled us to study phenology with an approach of in natura systems biology. I review recent analyses of FLOWERING LOCUS C (FLC), a temperature-responsive repressor of flowering, along the six steps in the typical flow of in natura systems biology. The extensive studies of the regulation of FLC have made this example a successful case in which a comprehensive understanding of gene functions has been progressing. The FLC-mediated long-term memory of past temperatures creates time lags with other seasonal signals, such as photoperiod and short-term temperature. Major signals that control flowering time have a phase lag between them under natural conditions, and hypothetical phase lag calendars are proposed as mechanisms of season detection in plants. Transcriptomic HMP brings a novel strategy to the study of molecular phenology, because it provides a comprehensive representation of plant functions. I discuss future perspectives of molecular phenology from the standpoints of molecular biology, evolutionary biology and ecology. © 2015 The Author. New Phytologist © 2015 New Phytologist Trust.

  11. Molecular Technologies in Serbian Lowland Forestry under Climate Changes - Possibilities and Perspectives

    Directory of Open Access Journals (Sweden)

    Branislav Trudić

    2014-12-01

    Full Text Available Background and Purpose: Vojvodina province, the northern part of the Republic of Serbia, is predominantly lowland agricultural region with over 75% of arable land which in previous years, has been highly impacted by drought. The annual precipitation is lower than 700 mm and it is the limit for the growth and development of natural forest vegetation. Unfortunately, the atmospheric precipitation is still a major source of water for plant biodiversity. Taking these facts into account, it is highly recommended to primarily use the xerothermic tree species, which have a well-developed root system for “classical” afforestation. Some species from Salicaceae and Fagaceae like poplars, willows, oaks and beeches are surely the best option for afforestation in temperate zones strongly influenced by drought. Conclusions: In order to develop stress-based genomic information in Populus and the rest of woody plant species from Vojvodina, an integrated genetic research needs to be done. The aim of this particular paper is to analyse and summarize data regarding stress-based biotechnology perspectives in Vojvodina and to give recommendations for future forest tree breeding. Drought as a strong negative ecological factor must be carefully considered. In order to achieve sustainability, new forest management plans must consider wide approaches, from molecular to ecosystem level.

  12. Toward Molecular Level of the “Salmonella-Victim” Ecology, Genetics, and Evolution

    Directory of Open Access Journals (Sweden)

    S.N. Rumyantsev

    2004-01-01

    Full Text Available Bacteria of the Salmonella genus are polypathogenic agents that can affect both men and animals, causing devastating and fatal illness. Despite considerable immunological, epidemiological, and genetic efforts, and increased understanding of how the Salmonella infection develops, many key questions concerning Salmonella infection remain unanswered. Salmonella can be carried as harmless commensals in some sectors of the population. In some individuals, however, the same microbes cause illness while others display immunity to primary Salmonella infection. Nothing is known about the molecular base of the Salmonella pathogenicity. Even the ability of Salmonella to destroy the victim’s cells has been the subject of century-long discussions. In this article, some key findings concerning ecology, molecular ecology, and cell level of the Salmonella infection genetics are summarized and interpreted from the viewpoint of evolutionary theory with certitude that this approach can help to decipher the undiscovered secrets of Salmonella infection’s epidemiology and pathogenesis, as well as the clinical course and severity, and to select ways for fighting against Salmonella.

  13. Stick and Slip Behaviour of Confined Oligomer Melts under Shear. A Molecular-Dynamics Study.

    NARCIS (Netherlands)

    Manias, E.; Hadziioannou, G.; Bitsanis, I.; Brinke, G. ten

    1993-01-01

    The flow behaviour of melts of short chains, confined in molecularly thin Couette flow geometries, is studied with molecular-dynamics simulations. The effect of wall attraction and confinement on the density and velocity profiles is analysed. In these highly inhomogeneous films, a strong correlation

  14. STICK AND SLIP BEHAVIOR OF CONFINED OLIGOMER MELTS UNDER SHEAR - A MOLECULAR-DYNAMICS STUDY

    NARCIS (Netherlands)

    MANIAS, E; HADZIIOANNOU, G; BITSANIS, [No Value; TENBRINKE, G

    1993-01-01

    The flow behaviour of melts of short chains, confined in molecularly thin Couette flow geometries, is studied with molecular-dynamics simulations. The effect of wall attraction and confinement on the density and velocity profiles is analysed. In these highly inhomogeneous films, a strong correlation

  15. Atomic level insights into realistic molecular models of dendrimer-drug complexes through MD simulations.

    Science.gov (United States)

    Jain, Vaibhav; Maiti, Prabal K; Bharatam, Prasad V

    2016-09-28

    Computational studies performed on dendrimer-drug complexes usually consider 1:1 stoichiometry, which is far from reality, since in experiments more number of drug molecules get encapsulated inside a dendrimer. In the present study, molecular dynamic (MD) simulations were implemented to characterize the more realistic molecular models of dendrimer-drug complexes (1:n stoichiometry) in order to understand the effect of high drug loading on the structural properties and also to unveil the atomistic level details. For this purpose, possible inclusion complexes of model drug Nateglinide (Ntg) (antidiabetic, belongs to Biopharmaceutics Classification System class II) with amine- and acetyl-terminated G4 poly(amidoamine) (G4 PAMAM(NH 2 ) and G4 PAMAM(Ac)) dendrimers at neutral and low pH conditions are explored in this work. MD simulation analysis on dendrimer-drug complexes revealed that the drug encapsulation efficiency of G4 PAMAM(NH 2 ) and G4 PAMAM(Ac) dendrimers at neutral pH was 6 and 5, respectively, while at low pH it was 12 and 13, respectively. Center-of-mass distance analysis showed that most of the drug molecules are located in the interior hydrophobic pockets of G4 PAMAM(NH 2 ) at both the pH; while in the case of G4 PAMAM(Ac), most of them are distributed near to the surface at neutral pH and in the interior hydrophobic pockets at low pH. Structural properties such as radius of gyration, shape, radial density distribution, and solvent accessible surface area of dendrimer-drug complexes were also assessed and compared with that of the drug unloaded dendrimers. Further, binding energy calculations using molecular mechanics Poisson-Boltzmann surface area approach revealed that the location of drug molecules in the dendrimer is not the decisive factor for the higher and lower binding affinity of the complex, but the charged state of dendrimer and drug, intermolecular interactions, pH-induced conformational changes, and surface groups of dendrimer do play an

  16. Atomic level insights into realistic molecular models of dendrimer-drug complexes through MD simulations

    Science.gov (United States)

    Jain, Vaibhav; Maiti, Prabal K.; Bharatam, Prasad V.

    2016-09-01

    Computational studies performed on dendrimer-drug complexes usually consider 1:1 stoichiometry, which is far from reality, since in experiments more number of drug molecules get encapsulated inside a dendrimer. In the present study, molecular dynamic (MD) simulations were implemented to characterize the more realistic molecular models of dendrimer-drug complexes (1:n stoichiometry) in order to understand the effect of high drug loading on the structural properties and also to unveil the atomistic level details. For this purpose, possible inclusion complexes of model drug Nateglinide (Ntg) (antidiabetic, belongs to Biopharmaceutics Classification System class II) with amine- and acetyl-terminated G4 poly(amidoamine) (G4 PAMAM(NH2) and G4 PAMAM(Ac)) dendrimers at neutral and low pH conditions are explored in this work. MD simulation analysis on dendrimer-drug complexes revealed that the drug encapsulation efficiency of G4 PAMAM(NH2) and G4 PAMAM(Ac) dendrimers at neutral pH was 6 and 5, respectively, while at low pH it was 12 and 13, respectively. Center-of-mass distance analysis showed that most of the drug molecules are located in the interior hydrophobic pockets of G4 PAMAM(NH2) at both the pH; while in the case of G4 PAMAM(Ac), most of them are distributed near to the surface at neutral pH and in the interior hydrophobic pockets at low pH. Structural properties such as radius of gyration, shape, radial density distribution, and solvent accessible surface area of dendrimer-drug complexes were also assessed and compared with that of the drug unloaded dendrimers. Further, binding energy calculations using molecular mechanics Poisson-Boltzmann surface area approach revealed that the location of drug molecules in the dendrimer is not the decisive factor for the higher and lower binding affinity of the complex, but the charged state of dendrimer and drug, intermolecular interactions, pH-induced conformational changes, and surface groups of dendrimer do play an

  17. New molecular insights into the pools and mechanisms of Arctic soil organic matter decomposition under warming

    Science.gov (United States)

    Gu, B.

    2017-12-01

    It is estimated that Arctic permafrost soils store approximately half of the global belowground organic carbon, which is susceptible to microbial decomposition under warming climate. Studies have shown that rates of soil organic carbon (SOC) decomposition are controlled not only by temperature but also SOC substrate quality or chemical composition. However, detailed molecular-scale characterization of SOC and its susceptibility to degradation are lacking, due to extremely complex nature of SOC. Here, ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) was utilized to determine compositional changes of SOC during a microcosm warming experiment using tundra soils that were collected from the Barrow Environmental Observatory in Alaska, USA. Soil microcosm incubation was conducted with both organic and mineral active layer soils at two temperatures (-2°C and 8°C) up to 122 days, and water-extractable SOC was analyzed. Results indicate that peptides, amino sugars, and carbohydrate-like compounds are among the most labile SOC compounds to be degraded, with nitrogen-containing compounds degrading at a much faster rate than those containing no nitrogen. Refractory SOC components are dominated by the lignin- or tannin-like compounds and, to a less extent, the aliphatic compounds. Additionally, elemental ratios of O:C, H:C, and N:C were found to decrease with incubation time, and SOC in the mineral soil exhibited lower O:C and N:C ratios than those of the organic-rich soil. A biodegradation index is proposed to facilitate the incorporation of mass spectrometry data into mechanistic models of SOC degradation and thus improved prediction model of climate feedbacks in the Arctic.

  18. Plasma Level Formaldehyde in Children Receiving Pulpotomy Treatment under General Anesthesia.

    Science.gov (United States)

    Bagrizan, Majid; Pourgolshani, Pouya; Hosseinpour, Sepanta; Jalalpour, Golnoush; Shahrestani, Mostafa Zahmatkesh

    Formocresol has long been used by dentists for pulpotomy of primary teeth. Due to some concerns regarding its possible carcinogenicity, formocresol has been the topic of numerous studies. This study sought to assess the changes in plasma level of formaldehyde of children after receiving pulpotomy under general anesthesia. Twenty-five children between 2-6 years requiring dental treatments under general anesthesia were studied. Blood samples were taken of children before and after the procedure. Plasma level of formaldehyde was measured using high performance liquid chromatography (HPLC). A total of 106 pulpotomy treatments were performed in 25 children using 126 cotton pellets dipped in formocresol. An increase and a decrease in plasma level of formaldehyde were noted in 5 (20%) and 20 (80%) children, respectively post-operatively compared to baseline. The t-test showed no significant difference in plasma level of formaldehyde pre- and postoperatively (P=0.12). the plasma level of formaldehyde in children who had higher levels of formaldehyde prior to the operation was also higher than that of others after the operation and this association was statistically significant (P=0.001, r=0.64). The results showed no significant change in the mean plasma level of formaldehyde in children who received pulpotomy under general anesthesia compared to its baseline value.

  19. Molecular-level insights into intrinsic peroxidase-like activity of nanocarbon oxides.

    Science.gov (United States)

    Zhao, Ruisheng; Zhao, Xiang; Gao, Xingfa

    2015-01-12

    Nanocarbon oxides have been proved to possess great peroxidase-like activity, catalyzing the oxidation of many peroxidase substrates, such as 3,3',5,5'-tetramethylbenzidine (TMB) and o-phenylenediamine dihydrochloride (OPD), accompanied by a significant color change. This chromogenic reaction is widely used to detect glucose and occult blood. The chromogenic reaction was intensively investigated with density functional theory and molecular-level insights into the nature of peroxidase-like activity were gained. A radical mechanism was unraveled and the carboxyl groups of nanocarbon oxides were identified as the reactive sites. Aromatic domains connected with the carboxyl groups were critical to the peroxidase-like activity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Observation of a level crossing in a molecular nanomagnet using implanted muons.

    Science.gov (United States)

    Lancaster, T; Möller, J S; Blundell, S J; Pratt, F L; Baker, P J; Guidi, T; Timco, G A; Winpenny, R E P

    2011-06-22

    We have observed an electronic energy level crossing in a molecular nanomagnet (MNM) using muon spin relaxation. This effect, not observed previously despite several muon studies of MNM systems, provides further evidence that the spin relaxation of the implanted muon is sensitive to the dynamics of the electronic spin. Our measurements on a broken ring MNM [H(2)N(t)Bu(is)Pr][Cr(8)CdF(9)(O(2)CC(CH(3))(3))(18)], which contains eight Cr ions, show clear evidence for the S = 0 --> S = 1 transition that takes place at B(c) = 2.3 T. The crossing is observed as a resonance-like dip in the average positron asymmetry and also in the muon spin relaxation rate, which shows a sharp increase in magnitude at the transition and a peak centred within the S = 1 regime.

  1. Molecular Processes Underlying the Structure and Assembly of Thin Films and Nanoparticles at Complex interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Richmond, Geraldine [Univ. of Oregon, Eugene, OR (United States)

    2016-06-03

    Since 1995 we have pursued a number of different studies that are quite diverse in nature but with the common theme of using novel laser based methods to study important processes at buried interfaces. Studies of Corrosion, Passivation on n-GaAs(100)Methanol Photoelectrochemical Cell In these studies we have used picosecond photoluminescence and electrochemical studies to understand the GaAs/methanol interface. In our most extensive set of studies we conducted photo-illumination and XPS experiments to understand the chemistry occurring in the GaAs/methanol photoelectrochemical during photoexcitation. An important distinction between photocorrosion and photoetching of GaAs is elucidated by these studies. The dependence of GaAs photocorrosion on light intensity has been explored to better understand intrinsic differences between the lamplight studies and the picosecond photoluminescence studies. The effect of coating the GaAs with a sulfide layer prior to immersion in the cell has also been explored. This last result has led us to examine n-GaAs as a function of crystallographic orientation after exposure to aqueous Na2S containing solutions has been studied as a function of crystallographic orientation of the GaAs surface. The (100) and (110) surfaces are relatively similar, with significant amounts of As-S species present at the interface. The (111)B surface lacks this constituent, but shows significant amounts of metallic As. The XPS results have been correlated with the results of previous photocorrosion and passivation studies conducted in a photoelectrochemical cell. The studies indicate that the metallic As present at (111)B surface contributes strongly to the large surface recombination velocity found there, and to the inability of Na2S to passivate the (111)B surface. SAMS Under Water: Water Molecular Structure and Bonding at Hydrophobic Surfaces In these DOE sponsored studies we have been interested in learning the similarities and

  2. Gas Exchange Characteristics in Tectona grandis L. Clones under Varying Concentrations of CO2 Levels

    Directory of Open Access Journals (Sweden)

    S. Saravanan

    2014-08-01

    Full Text Available The Institute of Forest Genetics and Tree Breeding, Coimbatore, India functioning under the Indian Council of Forestry Research and Education, Dehara Dun, has a long term systematic tree improvement program for Tectona grandis aimed to enhancing productivity and screening of clones for site specific. In the process, twenty clones of T. grandis L. were studied for the physiological parameters and water use efficiency with reference to the elevated CO2 levels. CO2 enrichment studies in special chambers help in understanding the changes at individual level, and also at physiological, biochemical and genetic level. It also provides valuable information for establishing plantations at different geographic locations. Considerable variations were observed when the selected 20 clones of T. grandis were subjected to physiological studies under elevated CO2 conditions (600 and 900 mol mol-1. Eight clones exhibited superior growth coupled with favorable physiological characteristics including high photosynthetic rate, carboxylation and water use efficiency under elevated CO2 levels. Clones with minimal variation in physiological characteristics under elevated levels of CO2 suggest their ability to overcome physiological stresses and adapt to varying climatic conditions.

  3. RNA-Seq and molecular docking reveal multi-level pesticide resistance in the bed bug

    Directory of Open Access Journals (Sweden)

    Mamidala Praveen

    2012-01-01

    Full Text Available Abstract Background Bed bugs (Cimex lectularius are hematophagous nocturnal parasites of humans that have attained high impact status due to their worldwide resurgence. The sudden and rampant resurgence of C. lectularius has been attributed to numerous factors including frequent international travel, narrower pest management practices, and insecticide resistance. Results We performed a next-generation RNA sequencing (RNA-Seq experiment to find differentially expressed genes between pesticide-resistant (PR and pesticide-susceptible (PS strains of C. lectularius. A reference transcriptome database of 51,492 expressed sequence tags (ESTs was created by combining the databases derived from de novo assembled mRNA-Seq tags (30,404 ESTs and our previous 454 pyrosequenced database (21,088 ESTs. The two-way GLMseq analysis revealed ~15,000 highly significant differentially expressed ESTs between the PR and PS strains. Among the top 5,000 differentially expressed ESTs, 109 putative defense genes (cuticular proteins, cytochrome P450s, antioxidant genes, ABC transporters, glutathione S-transferases, carboxylesterases and acetyl cholinesterase involved in penetration resistance and metabolic resistance were identified. Tissue and development-specific expression of P450 CYP3 clan members showed high mRNA levels in the cuticle, Malpighian tubules, and midgut; and in early instar nymphs, respectively. Lastly, molecular modeling and docking of a candidate cytochrome P450 (CYP397A1V2 revealed the flexibility of the deduced protein to metabolize a broad range of insecticide substrates including DDT, deltamethrin, permethrin, and imidacloprid. Conclusions We developed significant molecular resources for C. lectularius putatively involved in metabolic resistance as well as those participating in other modes of insecticide resistance. RNA-Seq profiles of PR strains combined with tissue-specific profiles and molecular docking revealed multi-level insecticide

  4. Promotion of Glucose Uptake in C2C12 Myotubes by Cereal Flavone Tricin and Its Underlying Molecular Mechanism.

    Science.gov (United States)

    Kim, Sohyun; Go, Gwang-Woong; Imm, Jee-Young

    2017-05-17

    The effect of tricin, a methylated flavone widely distributed in cereals, on glucose uptake and the underlying molecular mechanism was investigated using C2C12 myotubes. Tricin significantly increased glucose uptake in C2C12 myotubes, regardless of the absence (1.4-fold at 20 μM) or presence (1.6-fold at 20 μM) of insulin. The GLUT4 expression on the plasma membrane was increased 1.6-fold after tricin treatment (20 μM) in the absence of insulin. Tricin treatment significantly activated the insulin-dependent cell signaling pathway, including the activation of insulin receptor substrate-1 (IRS1), phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), and AKT substrate of 160 kDa (AS160). The oral administration of tricin (64 and 160 mg kg -1 of body weight day -1 ) also significantly lowered blood glucose levels in glucose-loaded C57BL/6 mice (p < 0.05). These results suggest that tricin has great potential to be used as a functional agent for glycemic control.

  5. Performance analysis of Brazilian highways under concession through the capacity and level of service

    OpenAIRE

    Santos, Túlio; Ribeiro, Paulo

    2016-01-01

    [EN], This paper proposes the development of a methodology to analyze the performance of highways under concession through the capacity and level of service, with special attention to Brazilian highways. The trajectory of transport infrastructure provision in Brazil and its performance assessment framework are mentioned, as well as an approach of the level of service concept and the Highway Capacity Manual (HCM). An inventory of the highway with the necessary data to the model ...

  6. Who regulates the disposal of low-level radioactive waste under the Low-Level Radioactive Waste Policy Act

    International Nuclear Information System (INIS)

    Mostaghel, D.M.

    1988-01-01

    The present existence of immense quantities of low-level nuclear waste, a federal law providing for state or regional control of such waste disposal, and a number of state disposal laws challenged on a variety of constitutional grounds underscore what currently may be the most serious problem in nuclear waste disposal: who is to regulate the disposal of low-level nuclear wastes. This problem's origin may be traced to crucial omissions in the Atomic Energy Act of 1946 and its 1954 amendments (AEA) that concern radioactive waste disposal. Although the AEA states that nuclear materials and facilities are affected with the public interest and should be regulated to provide for the public health and safety, the statute fails to prescribe specific guidelines for any nuclear waste disposal. The Low-Level Radioactive Waste Policy Act of 1980 (LLRWPA) grants states some control over radioactive waste disposal, an area from which they were previously excluded by the doctrine of federal preemption. This Comment discusses the question of who regulates low-level radioactive waste disposal facilities by examining the following: the constitutional doctrines safeguarding federal government authority; area of state authority; grants of specific authority delegations under the LLRWPA and its amendment; and finally, potential problems that may arise depending on whether ultimate regulatory authority is deemed to rest with single states, regional compacts, or the federal government

  7. Analysis of molecular responses in plants under the conditions of excess-aluminium stress

    Energy Technology Data Exchange (ETDEWEB)

    Masaoka, Yoshikuni; Arakawa, Yusuke; Asanuma, Shuichi [Kyushu National Agricultural Experiment Station, Kumamoto (Japan)] [and others

    1999-02-01

    Recent soil environments in Kyushu and Okinawa regions have a possibility to impair agricultural products because elution of aluminum (Al) from the soil has been progressing because of its elution by soil acidification. In this study, {sup 26}Al-tracing method using tandem accelerator mass spectroscopy was applied to investigate the effects of aluminum in the soil on a few plants. The results showed that Al accumulation in mitochondria was several times of higher in Dayton, a Al-resistant strain of barley than kearney, a sensitive one. It was thus suggested that mitochondria, which has been known to participates in respiration and cell death (apoptosis), has also an important role in the physiological functions of Al. The growth of barley on the soil of pH 5.0 was significantly inhibited with Al and such growth inhibition was also observed in barley grown in hydroponics, especially, the growth of kearney was markedly inhibited. When the effects of 1 mM Al were compared between Dayton and kearney strains, there were large differences in the growth of their leaves. Then, the correlative resistance to Al and barley leaf stripe mosaic virus (BSMV) was examined in these two barley strains. The virus concentration in kearney leaves 30 days after an inoculation of BSMV was similar to that in Dayton ones. Under stress conditions with a low level Al, both strains infected with BSMW developed necrotic damages, whereas under the stress condition at a high level Al (100 {mu}M), they developed severe necrosis even without inoculation with BSMW. As an increase of the amount of absorbed Al, the phosphate concentration in the cell was decreased and the decrease was marked in the resistant strain, Dayton. (M.N.)

  8. Changes in levels of cell wall constituents in wheat seedlings grown under continuous hypergravity conditions

    Science.gov (United States)

    Wakabayashi, K.; Soga, K.; Kamisaka, S.; Hoson, T.

    Effects of continuous hypergravity stimuli on the amounts and composition of cell wall constituents were investigated in wheat shoots. Hypergravity (300 g) treatment for three days after germination increased the net amount of cell wall polysaccharides such as hemicellulose and cellulose, but reduced the shoot elongation. As a result, the amount of cell wall polysaccharides per unit length of shoot increased under hypergravity. The hemicellulose fraction contained polysaccharides in the middle and low molecular mass range (5 kDa-1 MDa) and increased in response to hypergravity. Also, the amounts of arabinose (Ara) and xylose (Xyl), the major sugar components of the hemicellulose fraction, increased under hypergravity conditions. In addition to wall polysaccharides, hypergravity increased the amounts of cell wall-bound phenolic acids, such as ferulic acid (FA) and diferulic acid (DFA). Furthermore, the activity of phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) was enhanced under hypergravity conditions. These results suggest that continuous hypergravity stimulates the synthesis of cell wall constituents, especially hemicellulosic arabinoxylans and cell wall-bound FA and DFA in wheat shoots. The increased PAL activity may promote the formation of FA and DFA. These changes in cell wall architecture may be involved in making rigid and tough cell walls under hypergravity conditions and thereby contribute to the ability of plant to sustain their structures against gravitational stimuli.

  9. ENVIROSUITE: USING STATE-OF-THE-ART SYNCHROTRON TECHNIQUES TO UNDERSTAND ENVIRONMENTAL REMEDIATION SCIENCE ISSUES AT THE MOLECULAR LEVEL

    International Nuclear Information System (INIS)

    FITTS, J.P.; KALB, P.D.; FRANCIS, A.J.; FUHRMANN, M.; DODGE, C.J.; GILLOW, J.B.

    2004-01-01

    Although DOE's Environmental Management program has made steady progress in cleaning up environmental legacies throughout the DOE complex, there are still significant remediation issues that remain to be solved. For example, DOE faces difficult challenges related to potential mobilization of radionuclides (e.g., actinides) and other hazardous contaminants in soils, removal and final treatment of high-level waste and residuals from leaking tanks, and the long-term stewardship of remediated sites and engineered disposal facilities, to name just a few. In some cases, new technologies and technology applications will be required based on current engineering expertise. In others, however, basic scientific research is needed to understand the mechanisms of how contaminants behave under specific conditions and how they interact with the environment, from which new engineering solutions can emerge. At Brookhaven National Laboratory (BNL) and Stony Brook University, scientists have teamed to use state-of-the-art synchrotron techniques to help understand the basic interactions of contaminants in the environment. Much of this work is conducted at the BNL National Synchrotron Light Source (NSLS), which is a user facility that provides high energy X-ray and ultraviolet photon beams to facilitate the examination of contaminants and materials at the molecular level. These studies allow us to determine how chemical speciation and structure control important parameters such as solubility, which in turn drive critical performance characteristics such as leaching. In one study for example, we are examining the effects of microbial activity on actinide contaminants under conditions anticipated at the Waste Isolation Pilot Plant. One possible outcome of this research is the identification of specific microbes that can trap uranium or other contaminants within the intracellular structure and help mitigate mobility. In another study, we are exploring the interaction of contaminants with

  10. Physio-biochemical and molecular mechanism underlying the enhanced heavy metal tolerance in highland barley seedlings pre-treated with low-dose gamma irradiation.

    Science.gov (United States)

    Wang, Xiaojie; Ma, Ruonan; Cui, Dongjie; Cao, Qing; Shan, Zhe; Jiao, Zhen

    2017-10-27

    Heavy metal pollution, as a consequence of rapid industrialization and urbanization, poses a threat to highland barley grown in Tibet. This study investigates the effect of different doses of gamma irradiation (50-300 Gy) on the physio-biochemical and molecular mechanism of highland barley under heavy metal stress. Growth data showed that 50-Gy gamma irradiation had the maximal beneficial effects on the highland barley seedlings under lead/cadmium stress. The results of oxidative parameters demonstrated that 50-Gy gamma-irradiated seedlings had lower hydrogen peroxide and malondialdehyde contents under lead/cadmium stress compared to non-irradiated seedlings. Moreover, the activities of antioxidant enzyme and proline levels in 50-Gy gamma-irradiated seedlings were drastically higher than those in non-irradiated seedlings under lead/cadmium stress. Additionally, transmission electron microscopy results revealed that the 50-Gy gamma-irradiated seedlings exhibited improved chloroplasts ultrastructure compared with non-irradiated seedlings exposed to lead/cadmium stress. Notably, transcriptional expression analysis showed that 50-Gy gamma irradiation could significantly affect the expression of genes related to heavy metal transport and abscisic acid metabolism under lead/cadmium stress. Collectively, these results provide insights into the physio-biochemical and molecular mechanisms of low-dose-gamma-irradiation-enhanced heavy metal tolerance in highland barley seedlings, thus proposing gamma irradiation as a potential technology to mitigate heavy metal toxicity in crops.

  11. Olfactory stem cells, a new cellular model for studying molecular mechanisms underlying familial dysautonomia.

    Directory of Open Access Journals (Sweden)

    Nathalie Boone

    Full Text Available BACKGROUND: Familial dysautonomia (FD is a hereditary neuropathy caused by mutations in the IKBKAP gene, the most common of which results in variable tissue-specific mRNA splicing with skipping of exon 20. Defective splicing is especially severe in nervous tissue, leading to incomplete development and progressive degeneration of sensory and autonomic neurons. The specificity of neuron loss in FD is poorly understood due to the lack of an appropriate model system. To better understand and modelize the molecular mechanisms of IKBKAP mRNA splicing, we collected human olfactory ecto-mesenchymal stem cells (hOE-MSC from FD patients. hOE-MSCs have a pluripotent ability to differentiate into various cell lineages, including neurons and glial cells. METHODOLOGY/PRINCIPAL FINDINGS: We confirmed IKBKAP mRNA alternative splicing in FD hOE-MSCs and identified 2 novel spliced isoforms also present in control cells. We observed a significant lower expression of both IKBKAP transcript and IKAP/hELP1 protein in FD cells resulting from the degradation of the transcript isoform skipping exon 20. We localized IKAP/hELP1 in different cell compartments, including the nucleus, which supports multiple roles for that protein. We also investigated cellular pathways altered in FD, at the genome-wide level, and confirmed that cell migration and cytoskeleton reorganization were among the processes altered in FD. Indeed, FD hOE-MSCs exhibit impaired migration compared to control cells. Moreover, we showed that kinetin improved exon 20 inclusion and restores a normal level of IKAP/hELP1 in FD hOE-MSCs. Furthermore, we were able to modify the IKBKAP splicing ratio in FD hOE-MSCs, increasing or reducing the WT (exon 20 inclusion:MU (exon 20 skipping ratio respectively, either by producing free-floating spheres, or by inducing cells into neural differentiation. CONCLUSIONS/SIGNIFICANCE: hOE-MSCs isolated from FD patients represent a new approach for modeling FD to better

  12. Elucidation of the Molecular Mechanisms Underlying Lymph Node Metastasis in Prostate Cancer

    National Research Council Canada - National Science Library

    Datta, Kaustubh

    2005-01-01

    .... This finding leads one to think that understanding the role of angiogenic molecules like VEGF-C and VEGF-D in molecular detail for lymphatic formation in prostate cancer will provide information...

  13. Competition between two wetland macrophytes under different levels of sediment saturation

    Directory of Open Access Journals (Sweden)

    Feng Li

    2015-02-01

    Full Text Available Plant-plant interactions have been widely studied under various environmental conditions. However, in wetland ecosystems how plant interactions change in response to variation in sediment saturation remains largely unclear, even though different levels of sediment saturation play important roles in determining plant growth performance in wetland ecosystems. To this end, a competition experiment with two typical wetland species, Carex brevicuspis (neighbor plant and Polygonum hydropiper (target plant, was conducted in a target-neighbor design. Two water levels (0 cm and -40 cm water levels representing waterlogged and drained sediments, respectively and three neighbor plant densities (0 plants m-2, 400 plants m-2, and 1600 plants m-2 were tested in a factorial design. Biomass accumulation of P. hydropiper decreased along with enhanced C. brevicuspis density in the waterlogged treatment. However, in the drained treatment, biomass accumulation did not change under two C. brevicuspis densities. Above-ground relative neighbor effect index (ARNE and relative neighbor effect index (RNE of C. brevicuspis on P. hydropiper increased along with enhanced C. brevicuspis density only under waterlogged conditions. The below-ground relative neighbor effect index (BRNE was not affected at the different water level and density treatments. The below-ground mass fraction of P. hydropiper was much higher in the waterlogged treatment than it was in the drained one, especially with no C. brevicuspis treatment. However, the leaf mass fraction displayed the opposite pattern. The longest root length of P. hydropiper was much shorter under waterlogged treatment than under the drained treatment. These results suggest that the competition intensity of C. brevicuspis to P. hydropiper increased along with increasing C. brevicuspis density only under waterlogged conditions. Moreover, this study also confirms that P. hydropiper can acclimate to water stress mainly through

  14. Molecular mechanisms underlying mancozeb-induced inhibition of TNF-alpha production

    International Nuclear Information System (INIS)

    Corsini, Emanuela; Viviani, Barbara; Birindelli, Sarah; Gilardi, Federica; Torri, Anna; Codeca, Ilaria; Lucchi, Laura; Bartesaghi, Stefano; Galli, Corrado L.; Marinovich, Marina; Colosio, Claudio

    2006-01-01

    Mancozeb, a polymeric complex of manganese ethylenebisdithiocarbamate with zinc salt, is widely used in agriculture as fungicide. Literature data indicate that ethylenebisdithiocarbamates (EBDTCs) may have immunomodulatory effects in humans. We have recently found in agricultural workers occupationally exposed to the fungicide mancozeb a statistically significant decrease in lipopolysaccharide (LPS)-induced tumor necrosis factor-alpha (TNF) production in leukocytes. TNF is an essential proinflammatory cytokine whose production is normally stimulated during an infection. The purpose of this work was to establish an in vitro model reflecting in vivo data and to characterize the molecular mechanism of action of mancozeb. The human promyelocytic cell line THP-1 was used as in vitro model to study the effects of mancozeb and its main metabolite ethylenthiourea (ETU) on LPS-induced TNF release. Mancozeb, but not ETU, at non-cytotoxic concentrations (1-100 μg/ml), induced a dose- and time-dependent inhibition of LPS-induced TNF release, reflecting in vivo data. The modulatory effect observed was not limited to mancozeb but also other EBDTCs, namely zineb and ziram, showed similar inhibitory effects. Mancozeb must be added before or simultaneously to LPS in order to observe the effect, indicating that it acts on early events triggered by LPS. It is known that nuclear factor-κB (NF-κB) tightly regulates TNF transcription. We could demonstrate that mancozeb, modulating LPS-induced reactive oxygen species generation, prevented IκB degradation and NF-κB nuclear translocation, which in turn resulted in decreased TNF production. To further understand the mechanism of the effect of mancozeb on TNF transcription, THP-1 cells were transfected with NF-κB promoter-luciferase construct, and the effect of mancozeb on luciferase activity was measured. Cells transfected with promoter constructs containing κB site showed decreased LPS-induced luciferase activity relative to control

  15. Deep level defects in dilute GaAsBi alloys grown under intense UV illumination

    Energy Technology Data Exchange (ETDEWEB)

    Mooney, P. M.; Tarun, Marianne; Beaton, D. A.; Mascarenhas, A.; Alberi, K.

    2016-07-21

    Dilute GaAs1-xBix alloys exhibiting narrow band edge photoluminescence (PL) were recently grown by molecular beam epitaxy (MBE) with the growth surface illuminated by intense UV radiation. To investigate whether the improved optical quality of these films results from a reduction in the concentration of deep level defects, p+/n and n+/p junction diodes were fabricated on both the illuminated and dark areas of several samples. Deep Level Transient Spectroscopy (DLTS) measurements show that the illuminated and dark areas of both the n- and p-type GaAs1-xBix epi-layers have similar concentrations of near mid-gap electron and hole traps, in the 1015 cm-3 range. Thus the improved PL spectra cannot be explained by a reduction in non-radiative recombination at deep level defects. We note that carrier freeze-out above 35 K is significantly reduced in the illuminated areas of the p-type GaAs1-xBix layers compared to the dark areas, allowing the first DLTS measurements of defect energy levels close to the valence band edge. These defect levels may account for differences in the PL spectra from the illuminated and dark areas of un-doped layers with a similar Bi fraction.

  16. Comparison of atomic-level and coarse-grained models for liquid hydrocarbons from molecular dynamics configurational entropy estimates

    NARCIS (Netherlands)

    Baron, R; de Vries, AH; Hunenberger, PH; van Gunsteren, WF

    2006-01-01

    Molecular liquids can be modeled at different levels of spatial resolution. In atomic-level (AL) models, all (heavy) atoms can be explicitly simulated. In coarse-grained (CG) models, particles (beads) that represent groups of covalently bound atoms are used as elementary units. Ideally, a CG model

  17. [Vulnerability assessment on the coastal wetlands in the Yangtze Estuary under sea-level rise].

    Science.gov (United States)

    Cui, Li-Fang; Wang, Ning; Ge, Zhen-Ming; Zhang, Li-Quan

    2014-02-01

    To study the response of coastal wetlands to climate change, assess the impacts of climate change on the coastal wetlands and formulate feasible and practical mitigation strategies are the important prerequisite for securing coastal ecosystems. In this paper, the possible impacts of sea level rise caused by climate change on the coastal wetlands in the Yangtze Estuary were analyzed by the Source-Pathway-Receptor-Consequence (SPRC) model and IPCC definition on the vulnerability. An indicator system for vulnerability assessment was established, in which sea-level rise rate, subsidence rate, habitat elevation, inundation threshold of habitat and sedimentation rate were selected as the key indicators. A quantitatively spatial assessment method based on the GIS platform was established by quantifying each indicator, calculating the vulnerability index and grading the vulnerability index for the assessment of coastal wetlands in the Yangtze Estuary under the scenarios of sea-level rise. The vulnerability assessments on the coastal wetlands in the Yangtze Estuary in 2030 and 2050 were performed under two sea-level rise scenarios (the present sea-level rise trend over recent 30 years and IPCC A1F1 scenario). The results showed that with the projection in 2030 under the present trend of sea-level rise (0.26 cm x a(-1)), 6.6% and 0.1% of the coastal wetlands were in the low and moderate vulnerabilities, respectively; and in 2050, 9.8% and 0.2% of the coastal wetlands were in low and moderate vulnerabilities, respectively. With the projection in 2030 under the A1F1 scenario (0.59 cm x a(-1)), 9.0% and 0.1% of the coastal wetlands were in the low and moderate vulnerabilities, respectively; and in 2050, 9.5%, 1.0% and 0.3% of the coastal wetlands were in the low, moderate and high vulnerabilities, respectively.

  18. Anthropogenic and climate influences on biogeochemical dynamics and molecular-level speciation of soil sulfur.

    Science.gov (United States)

    Solomon, Dawit; Lehmann, Johannes; Kinyangi, James; Pell, Alice; Theis, Janice; Riha, Susan; Ngoze, Solomon; Amelung, Wulf; Du Preez, Chris; Machado, Stephen; Ellert, Ben; Janzen, Henry

    2009-06-01

    The soil environment is a primary component of the global biogeochemical sulfur (S) cycle, acting as a source and sink of various S species and mediating oxidation state changes. However, ecological significance of the various S forms and the impacts of human intervention and climate on the amount and structural composition of these compounds are still poorly understood. We investigated the long-term influences of anthropogenically mediated transitions from natural to managed ecosystems on molecular-level speciation, biogeochemical dynamics, and the apparent temperature sensitivity of S moieties in temperate, subtropical, and tropical environments with mean annual temperature (MAT) ranging from 5 degrees C to 21 degrees C, using elemental analysis and X-ray absorption near-edge structure (XANES) spectroscopy. Land-use and land-cover changes led to the depletion of total soil S in all three ecoregions over a period of up to 103 years. The largest decline occurred from tropical forest agroecosystems (67% Kakamega and 76% Nandi, Kenya), compared to losses from temperate (36% at Lethbridge, Canada, and 40% at Pendleton, USA) and subtropical (48% at South Africa) grassland agroecosystems. The total S losses correlated significantly with MAT. Anthropogenic interventions profoundly altered the molecular-level composition and resulted in an apparent shift in oxidation states of organic S from native ecosystems composed primarily of S moieties in intermediate and highly reduced oxidation states toward managed agroecosystems dominated by organic S rich in strongly oxidized functionalities. The most prominent change occurred in thiols and sulfides, the proportion of which decreased by 46% (Lethbridge) and 57% (Pendleton) in temperate agroecosystems, by 46% in subtropical agroecosystems, and by 79% (Nandi) and 81% (Kakamega) in tropical agroecosystems. The proportion of organic S directly linked to O increased by 81%, 168%, 40%, 92%, and 85%, respectively. Among the various

  19. Quality in the pepper under different fertigation managements and levels of nitrogen and potassium

    Directory of Open Access Journals (Sweden)

    Francisco de Assis de Oliveira

    Full Text Available ABSTRACTThe rational use of nutrients is of fundamental importance for obtaining high productivity of high nutritional quality. This work was developed with the aim of evaluating the quality of pepper fruit grown under different fertigation managements and different levels of nitrogen and potassium. The experimental design was of randomised blocks in a 3 x 6 factorial scheme with four replications. The treatments resulted from the combination of three fertigation managements (M1-based on the rate of absorption; M2-monitoring the conductivity of the soil solution; M3-monitoring concentrations of N and K ions in the soil solution with six levels of N and K (N0K0, N50K50, N100K100, N150K150, N200K200 and N300K300 as a percentage of the recommended dosage for the crop under conventional fertigation (M1 or hydroponics (M2 and M3. Fruit quality was evaluated for the following characteristics: pH, soluble solids, titratable acidity, vitamin C content and the ratio of soluble solids to titratable acidity. The different fertigation managements only affected the levels of soluble solids (SS and titratable acidity (TA, reducing the SS and TA. The variables under study were adjusted for the levels of N and K using quadratic models.

  20. Do microplastic particles affect Daphnia magna at the morphological, life history and molecular level?

    Directory of Open Access Journals (Sweden)

    Hannes K Imhof

    Full Text Available Microplastic particles are ubiquitous not only in marine but also in freshwater ecosystems. However, the impacts of microplastics, consisting of a large variety of synthetic polymers, on freshwater organisms remains poorly understood. We examined the effects of two polymer mixtures on the morphology, life history and on the molecular level of the waterflea Daphnia magna (three different clones. Microplastic particles of ~40 μm were supplied at a low concentration (1% of the food particles leading to an average of ~30 particles in the digestive tract which reflects a high microplastic contamination but still resembles a natural situation. Neither increased mortality nor changes on the morphological (body length, width and tail spine length or reproductive parameters were observed for adult Daphnia. The analyses of juvenile Daphnia revealed a variety of small and rather subtle responses of morphological traits (body length, width and tail spine length. For adult Daphnia, alterations in expression of genes related to stress responses (i.e. HSP60, HSP70 & GST as well as of other genes involved in body function and body composition (i.e. SERCA were observed already 48h after exposure. We anticipate that the adverse effects of microplastic might be influenced by many additional factors like size, shape, type and even age of the particles and that the rather weak effects, as detected in a laboratory, may lead to reduced fitness in a natural multi-stressor environment.

  1. Energy level alignment and electron transport through metal/organic contacts. From interfaces to molecular electronics

    Energy Technology Data Exchange (ETDEWEB)

    Abad, Enrique

    2013-07-01

    A new calculational approach to describing metal/organic interfaces. A valuable step towards a better understanding of molecular electronics. Nominated as an outstanding contribution by the Autonomous University of Madrid. In recent years, ever more electronic devices have started to exploit the advantages of organic semiconductors. The work reported in this thesis focuses on analyzing theoretically the energy level alignment of different metal/organic interfaces, necessary to tailor devices with good performance. Traditional methods based on density functional theory (DFT), are not appropriate for analyzing them because they underestimate the organic energy gap and fail to correctly describe the van der Waals forces. Since the size of these systems prohibits the use of more accurate methods, corrections to those DFT drawbacks are desirable. In this work a combination of a standard DFT calculation with the inclusion of the charging energy (U) of the molecule, calculated from first principles, is presented. Regarding the dispersion forces, incorrect long range interaction is substituted by a van der Waals potential. With these corrections, the C60, benzene, pentacene, TTF and TCNQ/Au(111) interfaces are analyzed, both for single molecules and for a monolayer. The results validate the induced density of interface states model.

  2. Dynamic, mechanistic, molecular-level modelling of cyanobacteria: Anabaena and nitrogen interaction.

    Science.gov (United States)

    Hellweger, Ferdi L; Fredrick, Neil D; McCarthy, Mark J; Gardner, Wayne S; Wilhelm, Steven W; Paerl, Hans W

    2016-09-01

    Phytoplankton (eutrophication, biogeochemical) models are important tools for ecosystem research and management, but they generally have not been updated to include modern biology. Here, we present a dynamic, mechanistic, molecular-level (i.e. gene, transcript, protein, metabolite) model of Anabaena - nitrogen interaction. The model was developed using the pattern-oriented approach to model definition and parameterization of complex agent-based models. It simulates individual filaments, each with individual cells, each with genes that are expressed to yield transcripts and proteins. Cells metabolize various forms of N, grow and divide, and differentiate heterocysts when fixed N is depleted. The model is informed by observations from 269 laboratory experiments from 55 papers published from 1942 to 2014. Within this database, we identified 331 emerging patterns, and, excluding inconsistencies in observations, the model reproduces 94% of them. To explore a practical application, we used the model to simulate nutrient reduction scenarios for a hypothetical lake. For a 50% N only loading reduction, the model predicts that N fixation increases, but this fixed N does not compensate for the loading reduction, and the chlorophyll a concentration decreases substantially (by 33%). When N is reduced along with P, the model predicts an additional 8% reduction (compared to P only). © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  3. Do microplastic particles affect Daphnia magna at the morphological, life history and molecular level?

    Science.gov (United States)

    Rusek, Jakub; Thiel, Michaela; Wolinska, Justyna; Laforsch, Christian

    2017-01-01

    Microplastic particles are ubiquitous not only in marine but also in freshwater ecosystems. However, the impacts of microplastics, consisting of a large variety of synthetic polymers, on freshwater organisms remains poorly understood. We examined the effects of two polymer mixtures on the morphology, life history and on the molecular level of the waterflea Daphnia magna (three different clones). Microplastic particles of ~40 μm were supplied at a low concentration (1% of the food particles) leading to an average of ~30 particles in the digestive tract which reflects a high microplastic contamination but still resembles a natural situation. Neither increased mortality nor changes on the morphological (body length, width and tail spine length) or reproductive parameters were observed for adult Daphnia. The analyses of juvenile Daphnia revealed a variety of small and rather subtle responses of morphological traits (body length, width and tail spine length). For adult Daphnia, alterations in expression of genes related to stress responses (i.e. HSP60, HSP70 & GST) as well as of other genes involved in body function and body composition (i.e. SERCA) were observed already 48h after exposure. We anticipate that the adverse effects of microplastic might be influenced by many additional factors like size, shape, type and even age of the particles and that the rather weak effects, as detected in a laboratory, may lead to reduced fitness in a natural multi-stressor environment. PMID:29145427

  4. Do microplastic particles affect Daphnia magna at the morphological, life history and molecular level?

    Science.gov (United States)

    Imhof, Hannes K; Rusek, Jakub; Thiel, Michaela; Wolinska, Justyna; Laforsch, Christian

    2017-01-01

    Microplastic particles are ubiquitous not only in marine but also in freshwater ecosystems. However, the impacts of microplastics, consisting of a large variety of synthetic polymers, on freshwater organisms remains poorly understood. We examined the effects of two polymer mixtures on the morphology, life history and on the molecular level of the waterflea Daphnia magna (three different clones). Microplastic particles of ~40 μm were supplied at a low concentration (1% of the food particles) leading to an average of ~30 particles in the digestive tract which reflects a high microplastic contamination but still resembles a natural situation. Neither increased mortality nor changes on the morphological (body length, width and tail spine length) or reproductive parameters were observed for adult Daphnia. The analyses of juvenile Daphnia revealed a variety of small and rather subtle responses of morphological traits (body length, width and tail spine length). For adult Daphnia, alterations in expression of genes related to stress responses (i.e. HSP60, HSP70 & GST) as well as of other genes involved in body function and body composition (i.e. SERCA) were observed already 48h after exposure. We anticipate that the adverse effects of microplastic might be influenced by many additional factors like size, shape, type and even age of the particles and that the rather weak effects, as detected in a laboratory, may lead to reduced fitness in a natural multi-stressor environment.

  5. A Molecular Survey of Ulva (Chlorophyta) in Temperate Australia Reveals Enhanced Levels of Cosmopolitanism.

    Science.gov (United States)

    Kirkendale, Lisa; Saunders, Gary W; Winberg, Pia

    2013-02-01

    The green algal genus Ulva includes a speciose group of marine macroalgae inhabiting shallow seas worldwide. Although algal blooms in Asia highlight the opportunistic nature of several "nuisance" species, recent research clearly reveals important positive benefits of Ulva. Applied research requires accurate, reliable, and rapid identification, however, identification of Ulva spp. has met with con-siderable difficulty. Consequently, many have turned to molecular markers to aid in taxonomy. Previous studies of plants and algae have relied heavily on ITS and rbcL. Recently, tufA has been presented as a suitable barcoding gene to facilitate species-level identification of green macroalgae and it is used here to explore the diversity of Ulva spp. in temperate Australia. Ninety Ulva specimens collected from 38 sites across five states were sequenced for this gene region with exemplars from each genetic group also sequenced for rbcL to test for congruence. Collections of Australian Ulva spp. were compared to samples from Asia and North America and exhibited trends consistent with recent studies in terms of species relationships. Results support an overwhelmingly cosmopolitan flora in temperate Australia that contrasts with other Australasian surveys of Ulva that report a greater number of endemics and new species. Four new records, as well as numerous range extensions for taxa already known from the country, are documented. Evidence for three nonindigenous Ulva species in temperate Australia is discussed. © 2012 Phycological Society of America.

  6. Homeobox gene expression in acute myeloid leukemia is linked to typical underlying molecular aberrations

    NARCIS (Netherlands)

    K.S. Kramarzova (Karolina Skvarova); K. Fiser (Karel); E. Mejstříková (Ester); K. Rejlova (Katerina); M. Zaliova (Marketa); M.W.J. Fornerod (Maarten); H.A. Drabkin (Harry); M.M. van den Heuvel-Eibrink (Marry); J. Stary (Jan); J. Trka (Jan); J. Starkova (Julia)

    2014-01-01

    markdownabstract__Background:__ Although distinct patterns of homeobox (HOX) gene expression have been described in defined cytogenetic and molecular subsets of patients with acute myeloid leukemia (AML), it is unknown whether these patterns are the direct result of transcriptional alterations or

  7. On the effects of transforming the vibrational spectra of molecular systems under microwave radiation

    International Nuclear Information System (INIS)

    Serikov, A.A.

    1993-01-01

    This problem is analyzed within the quantum-classical theory of molecular spectra. It is shown that the above-mentioned spectrum transformation could be, in principle, realized in macromolecular systems with strong interaction, and attention is drawn to the resonance character of the effect. (author). 19 refs., 1 fig

  8. Essential Concepts and Underlying Theories from Physics, Chemistry, and Mathematics for "Biochemistry and Molecular Biology" Majors

    Science.gov (United States)

    Wright, Ann; Provost, Joseph; Roecklein-Canfield, Jennifer A.; Bell, Ellis

    2013-01-01

    Over the past two years, through an NSF RCN UBE grant, the ASBMB has held regional workshops for faculty members from around the country. The workshops have focused on developing lists of Core Principles or Foundational Concepts in Biochemistry and Molecular Biology, a list of foundational skills, and foundational concepts from Physics, Chemistry,…

  9. Dynamics of Polycomb chromatin domains under conditions of increased molecular crowding

    Czech Academy of Sciences Publication Activity Database

    Šmigová, J.; Juda, P.; Bártová, Eva; Raška, I.

    2013-01-01

    Roč. 105, č. 11 (2013), s. 519-534 ISSN 0248-4900 R&D Projects: GA ČR(CZ) GBP302/12/G157; GA MŠk(CZ) EE2.3.30.0030 Institutional support: RVO:68081707 Keywords : Molecular crowding * Nuclear subcompartments * Polycomb body Subject RIV: BO - Biophysics Impact factor: 3.872, year: 2013

  10. Excitation of high energy levels under laser exposure of suspensions of nanoparticles in liquids

    International Nuclear Information System (INIS)

    Shafeev, G.A.; Simakin, A.V.; Bozon-Verduraz, F.; Robert, M.

    2007-01-01

    Laser exposure of suspensions of nanoparticles in liquids leads to excitation of high energy levels in both liquid and nanoparticle material. The emission spectrum of the colloidal solution under exposure of a suspension metallic nanoparticles in water to radiation of a Nd:YAG laser of a picosecond range of pulse duration is discussed. Excitation of nuclear energy levels and neutron release is experimentally studied on the model system of transmutation of Hg into Au that occurs under exposure of Hg nanodrops suspended in D 2 O. The proposed mechanism involves: (i) emission of X-ray photons by Hg nanoparticles upon laser exposure, leading to neutron release from D 2 O, (ii) initiation of Hg → Au transmutation by the capture of neutrons. The effect of transmutation is more pronounced using 196 Hg isotope instead of Hg of natural isotope composition. The influence of laser pulse duration on the degree of transmutation (from fs through ns range) is discussed

  11. Excitation of high energy levels under laser exposure of suspensions of nanoparticles in liquids

    Science.gov (United States)

    Shafeev, G. A.; Simakin, A. V.; Bozon-Verduraz, F.; Robert, M.

    2007-12-01

    Laser exposure of suspensions of nanoparticles in liquids leads to excitation of high energy levels in both liquid and nanoparticle material. The emission spectrum of the colloidal solution under exposure of a suspension metallic nanoparticles in water to radiation of a Nd:YAG laser of a picosecond range of pulse duration is discussed. Excitation of nuclear energy levels and neutron release is experimentally studied on the model system of transmutation of Hg into Au that occurs under exposure of Hg nanodrops suspended in D 2O. The proposed mechanism involves: (i) emission of X-ray photons by Hg nanoparticles upon laser exposure, leading to neutron release from D 2O, (ii) initiation of Hg → Au transmutation by the capture of neutrons. The effect of transmutation is more pronounced using 196Hg isotope instead of Hg of natural isotope composition. The influence of laser pulse duration on the degree of transmutation (from fs through ns range) is discussed.

  12. Hyperfine Level Interactions of Diamond Nitrogen Vacancy Ensembles Under Transverse Magnetic Fields

    Science.gov (United States)

    2015-10-06

    transverse mag- netic bias field (B|| or B⊥) lifts this degeneracy, ener- getically separating the spin states and increasing sensi- tivity to magnetic or...light-trapping diamond waveguide geometry [19]. We lift the ms = ±1 degeneracy by ap- plying a static magnetic field and tune the microwave ex- citation...Hyperfine level interactions of diamond nitrogen vacancy ensembles under transverse magnetic fields Hannah Clevenson,1, 2, ∗ Edward H. Chen,1, 2

  13. Evolution of nitrate level in green lettuce conventional grown under natural conditions and aquaponic system

    OpenAIRE

    Flavius Blidariu; Drasovean Alexandru; Grozea Adrian; Radulov Isidora; Lalescu Dacian

    2013-01-01

    Aquaponics integrates growing plants without soil technology with aquaculture, having an important role in recovery of nutrients from effluents. The research aimed to evaluate nitrates level in lettuce (Lactuca sativa) conventional grown under natural conditions and in integrated aquaponic system with a recirculated aquaculture system designed for pikeperch growth (Sander lucioperca). Conventional production (54 plants) has been obtained in the field without fertilizer or pesticide management...

  14. Enhanced abundance of tintinnids under elevated CO2 level from coastal Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Biswas, H.; Gadi, S.D.; Venkataramana, V.; Bharathi, M.D.; Priyan, R.K.; Manjari, D.T.; DileepKumar, M.

    College of Arts, Science and Commerce for Women, Nuvem, Goa – 403 601, India 3 National Institute of Oceanography, Doan Paula, Goa 43004, India Address for correspondence: Dr. Haimanti Biswas, Regional Center, National Institute of Oceanography, 176... group. The present study was conducted to understand the responses of microzooplankton and phytoplankton community and their interactive effects under future predicted CO 2 level. Methods Between May 20 th and June 1 st 2010 surface seawater...

  15. Extreme sea levels under present and future climate: a pan-European database

    Directory of Open Access Journals (Sweden)

    Paprotny Dominik

    2016-01-01

    Full Text Available Continental or global studies of coastal flood hazard in the context of climate change encounter several obstacles. The primary concern is the limited coverage of sea level data, especially the high-frequency sort needed to analyse sea level extremes. In this paper we present the calculations of return periods of storm surge heights and water levels for the European coast. The analysis utilized simulations using Delft3D hydrodynamic model driven by meteorological data with temporal and spatial resolution, created under EURO-CORDEX activities. The simulations were calibrated using short- and long-term sea levels from over 150 gauges. Annual maxima of water levels were extracted from five simulations: 1971–2000 historical run as well as 2021–50 and 2071–2100 simulations based on two emissions scenarios each. Spatially varying sea level rise projections were also included. Annual maxima were then fitted to probability distributions in order to obtain the return periods. The results were combined with more than 70,000 coastal sections, so that they would be complimentary with a river flood hazard dataset developed in parallel. The study showed a good match between simulated and observed storm surge heights. It also shows large differences in future trends of water levels in Europe.

  16. Study on the Variation of Groundwater Level under Time-varying Recharge

    Science.gov (United States)

    Wu, Ming-Chang; Hsieh, Ping-Cheng

    2017-04-01

    The slopes of the suburbs come to important areas by focusing on the work of soil and water conservation in recent years. The water table inside the aquifer is affected by rainfall, geology and topography, which will result in the change of groundwater discharge and water level. Currently, the way to obtain water table information is to set up the observation wells; however, owing to that the cost of equipment and the wells excavated is too expensive, we develop a mathematical model instead, which might help us to simulate the groundwater level variation. In this study, we will discuss the groundwater level change in a sloping unconfined aquifer with impermeable bottom under time-varying rainfall events. Referring to Child (1971), we employ the Boussinesq equation as the governing equation, and apply the General Integral Transforms Method (GITM) to analyzing the groundwater level after linearizing the Boussinesq equation. After comparing the solution with Verhoest & Troch (2000) and Bansal & Das (2010), we get satisfactory results. To sum up, we have presented an alternative approach to solve the linearized Boussinesq equation for the response of groundwater level in a sloping unconfined aquifer. The present analytical results combine the effect of bottom slope and the time-varying recharge pattern on the water table fluctuations. Owing to the limitation and difficulty of measuring the groundwater level directly, we develop such a mathematical model that we can predict or simulate the variation of groundwater level affected by any rainfall events in advance.

  17. Explicit control of adaptive automation under different levels of environmental stress.

    Science.gov (United States)

    Sauer, Jürgen; Kao, Chung-Shan; Wastell, David; Nickel, Peter

    2011-08-01

    This article examines the effectiveness of three different forms of explicit control of adaptive automation under low- and high-stress conditions, operationalised by different levels of noise. In total, 60 participants were assigned to one of three types of automation design (free, prompted and forced choice). They were trained for 4 h on a highly automated simulation of a process control environment, called AutoCAMS. This was followed by a 4-h testing session under noise exposure and quiet conditions. Measures of performance, psychophysiology and subjective reactions were taken. The results showed that all three modes of explicit control of adaptive automation modes were able to attenuate the negative effects of noise. This was partly due to the fact that operators opted for higher levels of automation under noise. It also emerged that forced choice showed marginal advantages over the two other automation modes. Statement of Relevance: This work is relevant to the design of adaptive automation since it emphasises the need to consider the impact of work-related stressors during task completion. During the presence of stressors, different forms of operator support through automation may be required than under more favourable working conditions.

  18. How exogenous nitric oxide regulates nitrogen assimilation in wheat seedlings under different nitrogen sources and levels.

    Science.gov (United States)

    Balotf, Sadegh; Islam, Shahidul; Kavoosi, Gholamreza; Kholdebarin, Bahman; Juhasz, Angela; Ma, Wujun

    2018-01-01

    Nitrogen (N) is one of the most important nutrients for plants and nitric oxide (NO) as a signaling plant growth regulator involved in nitrogen assimilation. Understanding the influence of exogenous NO on nitrogen metabolism at the gene expression and enzyme activity levels under different sources of nitrogen is vitally important for increasing nitrogen use efficiency (NUE). This study investigated the expression of key genes and enzymes in relation to nitrogen assimilation in two Australian wheat cultivars, a popular high NUE cv. Spitfire and a normal NUE cv. Westonia, under different combinations of nitrogen and sodium nitroprusside (SNP) as the NO donor. Application of NO increased the gene expressions and activities of nitrogen assimilation pathway enzymes in both cultivars at low levels of nitrogen. At high nitrogen supplies, the expressions and activities of N assimilation genes increased in response to exogenous NO only in cv. Spitfire but not in cv. Westonia. Exogenous NO caused an increase in leaf NO content at low N supplies in both cultivars, while under high nitrogen treatments, cv. Spitfire showed an increase under ammonium nitrate (NH4NO3) treatment but cv. Westonia was not affected. N assimilation gene expression and enzyme activity showed a clear relationship between exogenous NO, N concentration and N forms in primary plant nitrogen assimilation. Results reveal the possible role of NO and different nitrogen sources on nitrogen assimilation in Triticum aestivum plants.

  19. How exogenous nitric oxide regulates nitrogen assimilation in wheat seedlings under different nitrogen sources and levels.

    Directory of Open Access Journals (Sweden)

    Sadegh Balotf

    Full Text Available Nitrogen (N is one of the most important nutrients for plants and nitric oxide (NO as a signaling plant growth regulator involved in nitrogen assimilation. Understanding the influence of exogenous NO on nitrogen metabolism at the gene expression and enzyme activity levels under different sources of nitrogen is vitally important for increasing nitrogen use efficiency (NUE. This study investigated the expression of key genes and enzymes in relation to nitrogen assimilation in two Australian wheat cultivars, a popular high NUE cv. Spitfire and a normal NUE cv. Westonia, under different combinations of nitrogen and sodium nitroprusside (SNP as the NO donor. Application of NO increased the gene expressions and activities of nitrogen assimilation pathway enzymes in both cultivars at low levels of nitrogen. At high nitrogen supplies, the expressions and activities of N assimilation genes increased in response to exogenous NO only in cv. Spitfire but not in cv. Westonia. Exogenous NO caused an increase in leaf NO content at low N supplies in both cultivars, while under high nitrogen treatments, cv. Spitfire showed an increase under ammonium nitrate (NH4NO3 treatment but cv. Westonia was not affected. N assimilation gene expression and enzyme activity showed a clear relationship between exogenous NO, N concentration and N forms in primary plant nitrogen assimilation. Results reveal the possible role of NO and different nitrogen sources on nitrogen assimilation in Triticum aestivum plants.

  20. Elucidation of polymer induced DNA condensation. Visualisation at the single molecular level

    International Nuclear Information System (INIS)

    Martin, Alison Laura

    2002-01-01

    DNA condensation is a phenomenon that has stimulated interest from biologists, physicists, and polymer chemists for decades. At the cellular level, this process is key to the packing of DNA within the nuclear envelope, and the exposure of the appropriate nucleic acid sequences in order for transcription to occur, and proteins to be produced. The advent of gene therapy has led to an invigoration of this subject area. In order to successfully deliver to, and transfect target cells, many delivery vectors condense the therapeutic DNA into small compact particles. The nature of these particles have a considerable influence on the ultimate expression of the administered nucleic acid material. In addition, at its most fundamental, DNA itself is a classical polyelectrolyte polymer, the behaviour of which has applicability to other charged polymeric systems. There are two core interwound themes to this investigation; the visualisation of DNA condensate morphology at ultra-resolution, and the elucidation of the mechanisms of formation of these structures. The technique of atomic force microscopy is central to these investigations. Methodologies have been devised allowing the visualisation of the tertiary structure and conformational behaviour of individual DNA condensates in near in situ conditions. Condensation of the nucleic acid material has been induced by two classes of cation; small molecular cations, like those found within eukaryotic cells, and a range of cationic polymers. The cationic polymers investigated all have considerable potential as gene delivery vectors. The resultant DNA condensates have been assessed and contrasted in terms of their tertiary morphology, lateral dimensions, and structural volume. Assessments have also been made regarding the influence of the molecular architecture of the cationic moiety and the nature of the input nucleic acid material on the resultant DNA condensates. With regard to the elucidation of the mechanisms of DNA condensate

  1. Probing molecular adsorbates with core-level spectroscopies: Electronic structure and bonding models

    Science.gov (United States)

    Fohlisch, Alexander

    Resonantly excited X-ray emission spectroscopy has been applied to study the valence electronic structure of molecular adsorbates in an atom specific and orbital symmetry selective manner. In combination with ab initio cluster calculations, electronic structure and bonding models have been derived. Existing models of surface chemical bonding have been reviewed and partially revised. Most notably, the bonding mechanism of carbon monoxide (CO) on transition and noble metals has been revised and is found to be the result of a strong covalent interaction between the CO orbitals and the metal bands within each orbital symmetry. A characteristic allylic configuration is found in the π system and strong polarization within the σ system. The equilibrium properties of adsorbed CO are the direct result of a balance between the repulsive σ-interaction and the attractive π-interaction both in terms of the total energy and the local bond properties. The bonding of ammonia (NH3) on the Cu(110) surface is found to be dominated by a large covalent interaction, which contrasts the previous model of a strong electrostatic interaction. Furthermore, adsorbate-adsorbate interaction leads to a tilted adsorption geometry. Ethylene (C2H4) on Cu(110) is adsorbed in the di-σ configuration, according to the generally accepted Dewar Chatt Duncanson model for hydrocarbon adsorption. The application and interpretation of resonantly excited X-ray emission on these systems also required a thorough discussion of the spectroscopic process. Another topic was the vibrational fine structure in the X-ray photoemission core-level main lines of adsorbed molecules. The observation of the vibrational fine structure in molecular adsorbates is remarkable, as it was previously thought impossible to observe due to solid state broadening contributions. A detailed analysis of the vibrational fine structure and the line profile makes it possible to study the electronic and geometric properties of the core

  2. A comparison of adaptive and adaptable automation under different levels of environmental stress.

    Science.gov (United States)

    Sauer, Juergen; Kao, Chung-Shan; Wastell, David

    2012-01-01

    The effectiveness of different forms of adaptive and adaptable automation was examined under low- and high-stress conditions, in the form of different levels of noise. Thirty-six participants were assigned to one of the three types of variable automation (adaptive event-based, adaptive performance-based and adaptable serving as a control condition). Participants received 3 h of training on a simulation of a highly automated process control task and were subsequently tested during a 4-h session under noise exposure and quiet conditions. The results for performance suggested no clear benefits of one automation control mode over the other two. However, it emerged that participants under adaptable automation adopted a more active system management strategy and reported higher levels of self-confidence than in the two adaptive control modes. Furthermore, the results showed higher levels of perceived workload, fatigue and anxiety for performance-based adaptive automation control than the other two modes. This study compared two forms of adaptive automation (where the automated system flexibly allocates tasks between human and machine) with adaptable automation (where the human allocates the tasks). The adaptable mode showed marginal advantages. This is of relevance, given that this automation mode may also be easier to design.

  3. Designing automation for complex work environments under different levels of stress.

    Science.gov (United States)

    Sauer, Juergen; Nickel, Peter; Wastell, David

    2013-01-01

    This article examines the effectiveness of different forms of static and adaptable automation under low- and high-stress conditions. Forty participants were randomly assigned to one of four experimental conditions, comparing three levels of static automation (low, medium and high) and one level of adaptable automation, with the environmental stressor (noise) being varied as a within-subjects variable. Participants were trained for 4 h on a simulation of a process control environment, called AutoCAMS, followed by a 2.5-h testing session. Measures of performance, psychophysiology and subjective reactions were taken. The results showed that operators preferred higher levels of automation under noise than under quiet conditions. A number of parameters indicated negative effects of noise exposure, such as performance impairments, physiological stress reactions and higher mental workload. It also emerged that adaptable automation provided advantages over low and intermediate static automation, with regard to mental workload, effort expenditure and diagnostic performance. The article concludes that for the design of automation a wider range of operational scenarios reflecting adverse as well as ideal working conditions needs to be considered. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  4. A molecular systems approach to modelling human skin pigmentation: identifying underlying pathways and critical components.

    Science.gov (United States)

    Raghunath, Arathi; Sambarey, Awanti; Sharma, Neha; Mahadevan, Usha; Chandra, Nagasuma

    2015-04-29

    Ultraviolet radiations (UV) serve as an environmental stress for human skin, and result in melanogenesis, with the pigment melanin having protective effects against UV induced damage. This involves a dynamic and complex regulation of various biological processes that results in the expression of melanin in the outer most layers of the epidermis, where it can exert its protective effect. A comprehensive understanding of the underlying cross talk among different signalling molecules and cell types is only possible through a systems perspective. Increasing incidences of both melanoma and non-melanoma skin cancers necessitate the need to better comprehend UV mediated effects on skin pigmentation at a systems level, so as to ultimately evolve knowledge-based strategies for efficient protection and prevention of skin diseases. A network model for UV-mediated skin pigmentation in the epidermis was constructed and subjected to shortest path analysis. Virtual knock-outs were carried out to identify essential signalling components. We describe a network model for UV-mediated skin pigmentation in the epidermis. The model consists of 265 components (nodes) and 429 directed interactions among them, capturing the manner in which one component influences the other and channels information. Through shortest path analysis, we identify novel signalling pathways relevant to pigmentation. Virtual knock-outs or perturbations of specific nodes in the network have led to the identification of alternate modes of signalling as well as enabled determining essential nodes in the process. The model presented provides a comprehensive picture of UV mediated signalling manifesting in human skin pigmentation. A systems perspective helps provide a holistic purview of interconnections and complexity in the processes leading to pigmentation. The model described here is extensive yet amenable to expansion as new data is gathered. Through this study, we provide a list of important proteins essential

  5. Biological mediators and periodontal regeneration: a review of enamel matrix proteins at the cellular and molecular levels.

    Science.gov (United States)

    Bosshardt, Dieter D

    2008-09-01

    Despite a large body of clinical and histological data demonstrating beneficial effects of enamel matrix proteins (EMPs) for regenerative periodontal therapy, it is less clear how the available biological data can explain the mechanisms underlying the supportive effects of EMPs. To analyse all available biological data of EMPs at the cellular and molecular levels that are relevant in the context of periodontal wound healing and tissue formation. A stringent systematic approach was applied using the key words "enamel matrix proteins" OR "enamel matrix derivative" OR "emdogain" OR "amelogenin". The literature search was performed separately for epithelial cells, gingival fibroblasts, periodontal ligament cells, cementoblasts, osteogenic/chondrogenic/bone marrow cells, wound healing, and bacteria. A total of 103 papers met the inclusion criteria. EMPs affect many different cell types. Overall, the available data show that EMPs have effects on: (1) cell attachment, spreading, and chemotaxis; (2) cell proliferation and survival; (3) expression of transcription factors; (4) expression of growth factors, cytokines, extracellular matrix constituents, and other macromolecules; and (5) expression of molecules involved in the regulation of bone remodelling. All together, the data analysis provides strong evidence for EMPs to support wound healing and new periodontal tissue formation.

  6. In situ sensing and modeling of molecular events at the cellular level

    Science.gov (United States)

    Yang, Ruiguo

    We developed the Atomic Force Microscopy (AFM) based nanorobot in combination with other nanomechanical sensors for the investigation of cell signaling pathways. The AFM nanorobotics hinge on the superior spatial resolution of AFM in imaging and extends it into the measurement of biological processes and manipulation of biological matters. A multiple input single output control system was designed and implemented to solve the issues of nanomanipulation of biological materials, feedback, response frequency and nonlinearity. The AFM nanorobotic system therefore provide the human-directed position, velocity and force control with high frequency feedback, and more importantly it can feed the operator with the real-time imaging of manipulation result from the fast-imaging based local scanning. The use of the system has taken the study of cellular process at the molecular scale into a new level. The cellular response to the physiological conditions can be significantly manifested in cellular mechanics. Dynamic mechanical property has been regarded as biomarkers, sometimes even regulators of the signaling and physiological processes, thus the name mechanobiology. We sought to characterize the relationship between the structural dynamics and the molecular dynamics and the role of them in the regulation of cell behavior. We used the AFM nanorobotics to investigate the mechanical properties in real-time of cells that are stimulated by different chemical species. These reagents could result in similar ion channel responses but distinctive mechanical behaviors. We applied these measurement results to establish a model that describes the cellular stimulation and the mechanical property change, a "two-hit" model that comprises the loss of cell adhesion and the initiation of cell apoptosis. The first hit was verified by functional experiments: depletion of Calcium and nanosurgery to disrupt the cellular adhesion. The second hit was tested by a labeling of apoptotic markers that

  7. Using a Molecular Dynamics Simulation to Investigate Asphalt Nano-Cracking under External Loading Conditions

    Directory of Open Access Journals (Sweden)

    Yue Hou

    2017-07-01

    Full Text Available Recent research shows that macro-scale cracking in asphalt binder may originate from its intrinsic defects at the nano-scale. In this paper, a molecular dynamics (MD simulation was conducted to evaluate the nucleation of natural defects in asphalt. The asphalt microstructure was modeled using an ensemble of three different types of molecules to represent a constituent species: asphaltenes, naphthene aromatics and saturates, where the weight proportion of 20:60:20 was used to create an asphalt-like ensemble of molecules. Tension force was then applied on the molecular boundaries to study the crack initiation and propagation. It was discovered that the natural distribution of atoms at microscale would affect the intrinsic defects in asphalt and further influence crack initiation and propagation in asphalt.

  8. Molecular packing changes of alkanethiols monolayers on Au(111) under applied pressure

    International Nuclear Information System (INIS)

    Barrena, E.; Ocal, C.; Salmeron, M.

    2000-01-01

    A study of the changes of molecular packing in self-assembled monolayers of alkylthiols on Au(111) induced by external pressure is presented. Atomic force microscopy (AFM) is used to apply pressure and to measure the height of islands of alkanethiols partially covering the gold surface. The islands are made of ordered straight chain alkylthiol molecules tilted from the surface normal. Their height was found to decrease in a stepwise manner as a function of the load applied by the tip. Simultaneous stepwise increases in friction force were observed. A simple geometrical model involving the interlocking of alkyl chains at specific molecular tilt angles can explain the observations. According to the model, tilts in both the nearest neighbor and the next-nearest neighbor directions are necessary. (c) 2000 American Institute of Physics

  9. Performance of high level waste forms and engineered barriers under repository conditions

    International Nuclear Information System (INIS)

    1991-02-01

    The IAEA initiated in 1977 a co-ordinated research programme on the ''Evaluation of Solidified High-Level Waste Forms'' which was terminated in 1983. As there was a continuing need for international collaboration in research on solidified high-level waste form and spent fuel, the IAEA initiated a new programme in 1984. The new programme, besides including spent fuel and SYNROC, also placed greater emphasis on the effect of the engineered barriers of future repositories on the properties of the waste form. These engineered barriers included containers, overpacks, buffer and backfill materials etc. as components of the ''near-field'' of the repository. The Co-ordinated Research Programme on the Performance of High-Level Waste Forms and Engineered Barriers Under Repository Conditions had the objectives of promoting the exchange of information on the experience gained by different Member States in experimental performance data and technical model evaluation of solidified high level waste forms, components of the waste package and the complete waste management system under conditions relevant to final repository disposal. The programme includes studies on both irradiated spent fuel and glass and ceramic forms as the final solidified waste forms. The following topics were discussed: Leaching of vitrified high-level wastes, modelling of glass behaviour in clay, salt and granite repositories, environmental impacts of radionuclide release, synroc use for high--level waste solidification, leachate-rock interactions, spent fuel disposal in deep geologic repositories and radionuclide release mechanisms from various fuel types, radiolysis and selective leaching correlated with matrix alteration. Refs, figs and tabs

  10. Projected global ground-level ozone impacts on vegetation under different emission and climate scenarios

    Directory of Open Access Journals (Sweden)

    P. Sicard

    2017-10-01

    Full Text Available The impact of ground-level ozone (O3 on vegetation is largely under-investigated at the global scale despite large areas worldwide that are exposed to high surface O3 levels. To explore future potential impacts of O3 on vegetation, we compared historical and projected surface O3 concentrations simulated by six global atmospheric chemistry transport models on the basis of three representative concentration pathways emission scenarios (i.e. RCP2.6, 4.5, 8.5. To assess changes in the potential surface O3 threat to vegetation at the global scale, we used the AOT40 metric. Results point out a significant exceedance of AOT40 in comparison with the recommendations of UNECE for the protection of vegetation. In fact, many areas of the Northern Hemisphere show that AOT40-based critical levels will be exceeded by a factor of at least 10 under RCP8.5. Changes in surface O3 by 2100 worldwide range from about +4–5 ppb in the RCP8.5 scenario to reductions of about 2–10 ppb in the most optimistic scenario, RCP2.6. The risk of O3 injury for vegetation, through the potential O3 impact on photosynthetic assimilation, decreased by 61 and 47 % under RCP2.6 and RCP4.5, respectively, and increased by 70 % under RCP8.5. Key biodiversity areas in southern and northern Asia, central Africa and North America were identified as being at risk from high O3 concentrations.

  11. Seed priming with polyethylene glycol regulating the physiological and molecular mechanism in rice (Oryza sativa L.) under nano-ZnO stress

    Science.gov (United States)

    Salah, Sheteiwy Mohamed; Yajing, Guan; Dongdong, Cao; Jie, Li; Aamir, Nawaz; Qijuan, Hu; Weimin, Hu; Mingyu, Ning; Jin, Hu

    2015-01-01

    The present study was designed to highlight the impact of seed priming with polyethylene glycol on physiological and molecular mechanism of two cultivars of Oryza sativa L. under different levels of zinc oxide nanorods (0, 250, 500 and 750 mg L−1). Plant growth parameters were significantly increased in seed priming with 30% PEG under nano-ZnO stress in both cultivars. Whereas, this increase was more prominent in cultivar Qian You No. 1 as compared to cultivar Zhu Liang You 06. Significant increase in photosynthetic pigment with PEG priming under stress. Antioxidant enzymes activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) as well as malondialdehyde (MDA) contents were significantly reduced with PEG priming under nano-ZnO stress. Gene expression analysis also suggested that expression of APXa, APXb, CATa, CATb, CATc, SOD1, SOD2 and SOD3 genes were down regulated with PEG priming as compared to non-primed seeds under stress. The ultrastructural analysis showed that leaf mesophyll and root cells were significantly damaged under nano-ZnO stress in both cultivars but the damage was prominent in Zhu Liang You 06. However, seed priming with PEG significantly alleviate the toxic effects of nano-ZnO stress and improved the cell structures of leaf and roots in both cultivars. PMID:26419216

  12. Toxic effects of pesticide mixtures at a molecular level: Their relevance to human health

    International Nuclear Information System (INIS)

    Hernández, Antonio F.; Parrón, Tesifón; Tsatsakis, Aristidis M.; Requena, Mar; Alarcón, Raquel; López-Guarnido, Olga

    2013-01-01

    Highlights: ► Toxic effects of pesticide mixtures can be independent, dose addition or interaction. ► Metabolic interactions involve inhibition or induction of detoxifying enzymes. ► Organophosphates can potentiate pyrethroid, carbaryl and triazine toxicity. ► Synergism occurs when two active pesticides elicit greater than additive toxicity. ► Endocrine disruptors have the potential for additivity rather than synergism. - Abstract: Pesticides almost always occur in mixtures with other ones. The toxicological effects of low-dose pesticide mixtures on the human health are largely unknown, although there are growing concerns about their safety. The combined toxicological effects of two or more components of a pesticide mixture can take one of three forms: independent, dose addition or interaction. Not all mixtures of pesticides with similar chemical structures produce additive effects; thus, if they act on multiple sites their mixtures may produce different toxic effects. The additive approach also fails when evaluating mixtures that involve a secondary chemical that changes the toxicokinetics of the pesticide as a result of its increased activation or decreased detoxification, which is followed by an enhanced or reduced toxicity, respectively. This review addresses a number of toxicological interactions of pesticide mixtures at a molecular level. Examples of such interactions include the postulated mechanisms for the potentiation of pyrethroid, carbaryl and triazine herbicides toxicity by organophosphates; how the toxicity of some organophosphates can be potentiated by other organophosphates or by previous exposure to organochlorines; the synergism between pyrethroid and carbamate compounds and the antagonism between triazine herbicides and prochloraz. Particular interactions are also addressed, such as those of pesticides acting as endocrine disruptors, the cumulative toxicity of organophosphates and organochlorines resulting in estrogenic effects and the

  13. Molecular Tools for the Selective Detection of Nine Diatom Species Biomarkers of Various Water Quality Levels

    Directory of Open Access Journals (Sweden)

    Lucia Cimarelli

    2015-05-01

    Full Text Available Our understanding of the composition of diatom communities and their response to environmental changes is currently limited by laborious taxonomic identification procedures. Advances in molecular technologies are expected to contribute more efficient, robust and sensitive tools for the detection of these ecologically relevant microorganisms. There is a need to explore and test phylogenetic markers as an alternative to the use of rRNA genes, whose limited sequence divergence does not allow the accurate discrimination of diatoms at the species level. In this work, nine diatom species belonging to eight genera, isolated from epylithic environmental samples collected in central Italy, were chosen to implement a panel of diatoms covering the full range of ecological status of freshwaters. The procedure described in this work relies on the PCR amplification of specific regions in two conserved diatom genes, elongation factor 1-a (eEF1-a and silicic acid transporter (SIT, as a first step to narrow down the complexity of the targets, followed by microarray hybridization experiments. Oligonucleotide probes with the potential to discriminate closely related species were designed taking into account the genetic polymorphisms found in target genes. These probes were tested, refined and validated on a small-scale prototype DNA chip. Overall, we obtained 17 highly specific probes targeting eEF1-a and SIT, along with 19 probes having lower discriminatory power recognizing at the same time two or three species. This basic array was validated in a laboratory setting and is ready for tests with crude environmental samples eventually to be scaled-up to include a larger panel of diatoms. Its possible use for the simultaneous detection of diatoms selected from the classes of water quality identified by the European Water Framework Directive is discussed.

  14. Molecular tools for the selective detection of nine diatom species biomarkers of various water quality levels.

    Science.gov (United States)

    Cimarelli, Lucia; Singh, Kumar Saurabh; Mai, Nguyen Thi Nhu; Dhar, Bidhan Chandra; Brandi, Anna; Brandi, Letizia; Spurio, Roberto

    2015-05-22

    Our understanding of the composition of diatom communities and their response to environmental changes is currently limited by laborious taxonomic identification procedures. Advances in molecular technologies are expected to contribute more efficient, robust and sensitive tools for the detection of these ecologically relevant microorganisms. There is a need to explore and test phylogenetic markers as an alternative to the use of rRNA genes, whose limited sequence divergence does not allow the accurate discrimination of diatoms at the species level. In this work, nine diatom species belonging to eight genera, isolated from epylithic environmental samples collected in central Italy, were chosen to implement a panel of diatoms covering the full range of ecological status of freshwaters. The procedure described in this work relies on the PCR amplification of specific regions in two conserved diatom genes, elongation factor 1-a (eEF1-a) and silicic acid transporter (SIT), as a first step to narrow down the complexity of the targets, followed by microarray hybridization experiments. Oligonucleotide probes with the potential to discriminate closely related species were designed taking into account the genetic polymorphisms found in target genes. These probes were tested, refined and validated on a small-scale prototype DNA chip. Overall, we obtained 17 highly specific probes targeting eEF1-a and SIT, along with 19 probes having lower discriminatory power recognizing at the same time two or three species. This basic array was validated in a laboratory setting and is ready for tests with crude environmental samples eventually to be scaled-up to include a larger panel of diatoms. Its possible use for the simultaneous detection of diatoms selected from the classes of water quality identified by the European Water Framework Directive is discussed.

  15. Early weight changes after birth and serum high-molecular-weight adiponectin level in preterm infants.

    Science.gov (United States)

    Yoshida, Tomohide; Nagasaki, Hiraku; Asato, Yoshihide; Ohta, Takao

    2011-12-01

    Extra-uterine growth retardation (EUGR) is associated with an increased risk for cardiometabolic diseases later in life. The aim of the present study was to examine the relationship between early weight change after birth in preterm infants and adiponectin (adn) multimeric complexes. Subjects included 28 preterm infants born between weeks 24 and 33 of gestation. Serum adn multimeric complexes and the anthropometric parameters were measured in preterm infants at birth and at corrected term. Bodyweight (BW) decreased during the first week of life, with birthweight restored at approximately 19 days after birth. Nineteen of the subjects had EUGR at corrected term. Total (T)-adn, high-molecular-weight (H)-adn, and the ratio of H-adn to T-adn (H/T-adn) were significantly elevated at corrected term than at birth. Postmenstrual age, birthweight, birth length and lowest BW after birth were positively correlated with H-adn and H/T-adn. Weight reduction after birth was negatively correlated with H-adn. Age to restore birthweight was negatively correlated with T-adn, H-adn and H/T-adn. Stepwise multiple regression analysis indicated age to restore birthweight as the major predictor of T-adn and H-adn. Early weight changes after birth may alter serum adn level in preterm infants at corrected term. The appropriate nutritional support in the early postnatal period could reduce the prevalence of EUGR and the future risk for cardiometabolic diseases. © 2011 The Authors. Pediatrics International © 2011 Japan Pediatric Society.

  16. Exploring the Impact of and Perceptions about Interactive, Self-Explaining Environments in Molecular-Level Animations

    Science.gov (United States)

    Falvo, David A.; Urban, Michael J.; Suits, Jerry P.

    2011-01-01

    This mixed-method study investigates the effects of interactivity in animations of a molecular-level process and explores perceptions about the animated learning tool used. Treatments were based on principles of cognitive psychology designed to study the main effects of treatment and spatial ability and their interaction. Results with students (n…

  17. Shark tales: a molecular species-level phylogeny of sharks (Selachimorpha, Chondrichthyes).

    Science.gov (United States)

    Vélez-Zuazo, Ximena; Agnarsson, Ingi

    2011-02-01

    Sharks are a diverse and ecologically important group, including some of the ocean's largest predatory animals. Sharks are also commercially important, with many species suffering overexploitation and facing extinction. However, despite a long evolutionary history, commercial, and conservation importance, phylogenetic relationships within the sharks are poorly understood. To date, most studies have either focused on smaller clades within sharks, or sampled taxa sparsely across the group. A more detailed species-level phylogeny will offer further insights into shark taxonomy, provide a tool for comparative analyses, as well as facilitating phylogenetic estimates of conservation priorities. We used four mitochondrial and one nuclear gene to investigate the phylogenetic relationships of 229 species (all eight Orders and 31 families) of sharks, more than quadrupling the number of taxon sampled in any prior study. The resulting Bayesian phylogenetic hypothesis agrees with prior studies on the major relationships of the sharks phylogeny; however, on those relationships that have proven more controversial, it differs in several aspects from the most recent molecular studies. The phylogeny supports the division of sharks into two major groups, the Galeomorphii and Squalimorphii, rejecting the hypnosqualean hypothesis that places batoids within sharks. Within the squalimorphs the orders Hexanchiformes, Squatiniformes, Squaliformes, and Pristiophoriformes are broadly monophyletic, with minor exceptions apparently due to missing data. Similarly, within Galeomorphs, the orders Heterodontiformes, Lamniformes, Carcharhiniformes, and Orectolobiformes are broadly monophyletic, with a couple of species 'misplaced'. In contrast, many of the currently recognized shark families are not monophyletic according to our results. Our phylogeny offers some of the first clarification of the relationships among families of the order Squaliformes, a group that has thus far received relatively

  18. Extracting physics of life at the molecular level: A review of single-molecule data analyses.

    Science.gov (United States)

    Colomb, Warren; Sarkar, Susanta K

    2015-06-01

    Studying individual biomolecules at the single-molecule level has proved very insightful recently. Single-molecule experiments allow us to probe both the equilibrium and nonequilibrium properties as well as make quantitative connections with ensemble experiments and equilibrium thermodynamics. However, it is important to be careful about the analysis of single-molecule data because of the noise present and the lack of theoretical framework for processes far away from equilibrium. Biomolecular motion, whether it is free in solution, on a substrate, or under force, involves thermal fluctuations in varying degrees, which makes the motion noisy. In addition, the noise from the experimental setup makes it even more complex. The details of biologically relevant interactions, conformational dynamics, and activities are hidden in the noisy single-molecule data. As such, extracting biological insights from noisy data is still an active area of research. In this review, we will focus on analyzing both fluorescence-based and force-based single-molecule experiments and gaining biological insights at the single-molecule level. Inherently nonequilibrium nature of biological processes will be highlighted. Simulated trajectories of biomolecular diffusion will be used to compare and validate various analysis techniques. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. A Security Level Classification Method for Power Systems under N-1 Contingency

    Directory of Open Access Journals (Sweden)

    Zhigang Lu

    2017-12-01

    Full Text Available Security assessment is crucial for the reliable and secure operation of power systems. This paper proposes a security level classification (SLC method to analyze the security level of power systems both qualitatively and quantitatively. In this SLC method, security levels are graded according to a comprehensive safety index (CSI, which is defined by integrating the system margin index (SMI and load entropy. The SMI depends on the operating load and the total supply capacity (TSC under N-1 contingency, and the load entropy reflects the heterogeneity of load distribution calculated from entropy theory. In order to calculate the TSC under N-1 contingency considering both of the computational accuracy and speed, the TSC is converted into an extended conic quadratic programming (ECQP model. In addition, the load boundary vector (LBV model is established to obtain the capacity limit of each load bus, and thus detect potential risks of power systems. Finally, two modified practical power systems and the IEEE 118-bus test system are studied to validate the feasibility of the proposed SLC method.

  20. Radial-interval linear programming for environmental management under varied protection levels.

    Science.gov (United States)

    Tan, Qian; Huang, Guo H; Cai, Yanpeng

    2010-09-01

    In this study, a radial-interval linear programming (RILP) approach was developed for supporting waste management under uncertainty. RILP improved interval-parameter linear programming and its extensions in terms of input reasonableness and output robustness. From the perspective of modeling inputs, RILP could tackle highly uncertain information at the bounds of interval parameters through introducing the concept of fluctuation radius. Regarding modeling outputs, RILP allows controlling the degree of conservatism associated with interval solutions and is capable of quantifying corresponding system risks and benefits. This could facilitate the reflection of interactive relationship between the feasibility of system and the uncertainty of parameters. A computationally tractable algorithm was provided to solve RILP. Then, a long-term waste management case was studied to demonstrate the applicability of the developed methodology. A series of interval solutions obtained under varied protection levels were compared, helping gain insights into the interactions among protection level, violation risk, and system cost. Potential waste allocation alternatives could be generated from these interval solutions, which would be screened in real-world practices according to various projected system conditions as well as decision-makers' willingness to pay and risk tolerance levels. Sensitivity analysis further revealed the significant impact of fluctuation radii of interval parameters on the system. The results indicated that RILP is applicable to a wide spectrum of environmental management problems that are subject to compound uncertainties.

  1. Understanding DNA Under Oxidative Stress and Sensitization: The Role of Molecular Modeling

    Directory of Open Access Journals (Sweden)

    Antonio eMonari

    2015-07-01

    Full Text Available DNA is constantly exposed to damaging threats coming from oxidative stress, i.e. from the presence of free radicals and reactive oxygen species. Sensitization from exogenous and endogenous compounds that strongly enhance the frequency of light-induced lesions also plays an important role. The experimental determination of DNA lesions, though a difficult subject, is somehow well established and allows to elucidate even extremely rare DNA lesions. In parallel, molecular modeling has become fundamental to clearly understand the fine mechanisms related to DNA defects induction. Indeed, it offers an unprecedented possibility to get access to an atomistic or even electronic resolution. Ab initio molecular dynamics may also describe the time-evolution of the molecular system and its reactivity. Yet the modeling of DNA (photo-reactions does necessitate elaborate multi-scale methodologies to tackle a damage induction reactivity that takes place in a complex environment. The double-stranded DNA environment is first characterized by a very high flexibility, that dynamical effects are to be taken into account, but also a strongly inhomogeneous electrostatic embedding. Additionally, one aims at capturing more subtle effects, such as the sequence selectivity which is of critical important for DNA damage. The structure and dynamics of the DNA/sensitizers complexes, as well as the photo-induced electron- and energy-transfer phenomena taking place upon sensitization, should be carefully modeled. Finally the factors inducing different repair ratios for different lesions should also be rationalized.In this review we will critically analyze the different computational strategies used to model DNA lesions. A clear picture of the complex interplay between reactivity and structural factors will be sketched. The use of proper multi-scale modeling leads to the in-depth comprehension of DNA lesions mechanism and also to the rational design of new chemo-therapeutic agents.

  2. Investigation of tribological properties of graphene oxide reinforced ultrahigh molecular weight polyethylene under artificial seawater lubricating condition

    Science.gov (United States)

    Pang, Wenchao; Ni, Zifeng; Wu, JiaLiang; Zhao, Yongwu

    2018-03-01

    A range of ultrahigh molecular weight polyethylene (UHMWPE)/graphene oxide (GO) nanocomposites were fabricated using liquid-phase ultrasonication mixing followed by hot-pressing. The wettability, water absorption and corrosion resistance of composites were studied to prove the composites were suitable for application in liquid environment. The tribological properties of composites under dry, deionized water and seawater lubricating condition were investigated. The results showed that the incorporation of GO decreased the wear rate of UHMWPE under different lubricating conditions and with the increase of GO addition, the wear rate of UHMWPE/GO composites decreased. UHMWPE/GO composites exhibited better tribological behaviors under seawater lubricating condition than other conditions, because good corrosion resistance and excellent wear resistance of UHMWPE/GO composites, and the lubricating effect of seawater is also indispensable.

  3. Molecular mechanisms underlying the regulation of brain-derived neurotrophic factor (BDNF) translation in dendrites

    OpenAIRE

    Pinheiro, Vera Lúcia Margarido

    2010-01-01

    Dissertação de mestrado em Biologia Celular e Molecular apresentada ao Departamento de Ciências da Vida da Faculdade de Ciências e Tecnologia da Universidade de Coimbra A especificidade espacial e temporal subjacente à diversidade de processos de plasticidade sináptica que ocorrem no sistema nervoso central está profundamente relacionada com a disponibilidade da proteína brain-derived neurotrophic factor (BDNF) em domínios sub-celulares distintos, especialmente na área pós-sinápti...

  4. Precision bragg reflectors obtained by molecular beam epitaxy under in situ tunable dynamic reflectometry control

    Energy Technology Data Exchange (ETDEWEB)

    Bardinal, V.; Legros, R.; Fontaine, C.

    1995-12-31

    Highly accurate layer thickness are required for multilayers involved in photonic devices, such as Bragg reflectors. In this letter, we demonstrate that precise, real-time monitoring of molecular beam epitaxy growing layers can be achieved by near-normal incidence dynamic reflectometry with a tunable sapphire-titanium laser used as a source. The advantage of this new technique lies in the possibility of synchronizing the material changes and the reflectivity extrema by selecting adequate analysis wavelengths. This technique is shown to provide 885 nm GaAs-AlAs Bragg reflectors with a layer thickness accuracy in excess of 1%. (author). 17 refs.

  5. Modeling Caspian Sea water level oscillations under different scenarios of increasing atmospheric carbon dioxide concentrations

    Directory of Open Access Journals (Sweden)

    Roshan GholamReza

    2012-12-01

    Full Text Available Abstract The rapid rise of Caspian Sea water level (about 2.25 meters since 1978 has caused much concern to all five surrounding countries, primarily because flooding has destroyed or damaged buildings and other engineering structures, roads, beaches and farm lands in the coastal zone. Given that climate, and more specifically climate change, is a primary factor influencing oscillations in Caspian Sea water levels, the effect of different climate change scenarios on future Caspian Sea levels was simulated. Variations in environmental parameters such as temperature, precipitation, evaporation, atmospheric carbon dioxide and water level oscillations of the Caspian sea and surrounding regions, are considered for both past (1951-2006 and future (2025-2100 time frames. The output of the UKHADGEM general circulation model and five alternative scenarios including A1CAI, BIASF, BIMES WRE450 and WRE750 were extracted using the MAGICC SCENGEN Model software (version 5.3. The results suggest that the mean temperature of the Caspian Sea region (Bandar-E-Anzali monitoring site has increased by ca. 0.17°C per decade under the impacts of atmospheric carbon dioxide changes (r=0.21. The Caspian Sea water level has increased by ca. +36cm per decade (r=0.82 between the years 1951-2006. Mean results from all modeled scenarios indicate that the temperature will increase by ca. 3.64°C and precipitation will decrease by ca. 10% (182 mm over the Caspian Sea, whilst in the Volga river basin, temperatures are projected to increase by ca. 4.78°C and precipitation increase by ca. 12% (58 mm by the year 2100. Finally, statistical modeling of the Caspian Sea water levels project future water level increases of between 86 cm and 163 cm by the years 2075 and 2100, respectively.

  6. Modeling Caspian Sea water level oscillations under different scenarios of increasing atmospheric carbon dioxide concentrations.

    Science.gov (United States)

    Roshan, Gholamreza; Moghbel, Masumeh; Grab, Stefan

    2012-12-12

    The rapid rise of Caspian Sea water level (about 2.25 meters since 1978) has caused much concern to all five surrounding countries, primarily because flooding has destroyed or damaged buildings and other engineering structures, roads, beaches and farm lands in the coastal zone. Given that climate, and more specifically climate change, is a primary factor influencing oscillations in Caspian Sea water levels, the effect of different climate change scenarios on future Caspian Sea levels was simulated. Variations in environmental parameters such as temperature, precipitation, evaporation, atmospheric carbon dioxide and water level oscillations of the Caspian sea and surrounding regions, are considered for both past (1951-2006) and future (2025-2100) time frames. The output of the UKHADGEM general circulation model and five alternative scenarios including A1CAI, BIASF, BIMES WRE450 and WRE750 were extracted using the MAGICC SCENGEN Model software (version 5.3). The results suggest that the mean temperature of the Caspian Sea region (Bandar-E-Anzali monitoring site) has increased by ca. 0.17°C per decade under the impacts of atmospheric carbon dioxide changes (r=0.21). The Caspian Sea water level has increased by ca. +36cm per decade (r=0.82) between the years 1951-2006. Mean results from all modeled scenarios indicate that the temperature will increase by ca. 3.64°C and precipitation will decrease by ca. 10% (182 mm) over the Caspian Sea, whilst in the Volga river basin, temperatures are projected to increase by ca. 4.78°C and precipitation increase by ca. 12% (58 mm) by the year 2100. Finally, statistical modeling of the Caspian Sea water levels project future water level increases of between 86 cm and 163 cm by the years 2075 and 2100, respectively.

  7. Light Levels Affect Carbon Utilisation in Tropical Seagrass under Ocean Acidification.

    Directory of Open Access Journals (Sweden)

    Yan X Ow

    Full Text Available Under future ocean acidification (OA, increased availability of dissolved inorganic carbon (DIC in seawater may enhance seagrass productivity. However, the ability to utilise additional DIC could be regulated by light availability, often reduced through land runoff. To test this, two tropical seagrass species, Cymodocea serrulata and Halodule uninervis were exposed to two DIC concentrations (447 μatm and 1077 μatm pCO2, and three light treatments (35, 100, 380 μmol m(-2 s(-1 for two weeks. DIC uptake mechanisms were separately examined by measuring net photosynthetic rates while subjecting C. serrulata and H. uninervis to changes in light and addition of bicarbonate (HCO3- use inhibitors (carbonic anhydrase inhibitor, acetazolamide and TRIS buffer (pH 8.0. We observed a strong dependence on energy driven H+-HCO3- co-transport (TRIS, which disrupts H+ extrusion in C. serrulata under all light levels, indicating greater CO2 dependence in low light. This was confirmed when, after two weeks exposure, DIC enrichment stimulated maximum photosynthetic rates (Pmax and efficiency (α more in C. serrulata grown under lower light levels (36-60% increase than for those in high light (4% increase. However, C. serrulata growth increased with both DIC enrichment and light levels. Growth, NPP and photosynthetic responses in H. uninervis increased with higher light treatments and were independent of DIC availability. Furthermore, H. uninervis was found to be more flexible in HCO3- uptake pathways. Here, light availability influenced productivity responses to DIC enrichment, via both carbon fixation and acquisition processes, highlighting the role of water quality in future responses to OA.

  8. Molecular Mechanisms Underlying Curcumin-Mediated Therapeutic Effects in Type 2 Diabetes and Cancer

    Directory of Open Access Journals (Sweden)

    Marzena Wojcik

    2018-01-01

    Full Text Available The growing prevalence of age-related diseases, especially type 2 diabetes mellitus (T2DM and cancer, has become global health and economic problems. Due to multifactorial nature of both diseases, their pathophysiology is not completely understood so far. Compelling evidence indicates that increased oxidative stress, resulting from an imbalance between production of reactive oxygen species (ROS and their clearance by antioxidant defense mechanisms, as well as the proinflammatory state contributes to the development and progression of the diseases. Curcumin (CUR; diferuloylmethane, a well-known polyphenol derived from the rhizomes of turmeric Curcuma longa, has attracted a great deal of attention as a natural compound with beneficial antidiabetic and anticancer properties, partly due to its antioxidative and anti-inflammatory actions. Although this polyphenolic compound is increasingly being recognized for its growing number of protective health effects, the precise molecular mechanisms through which it reduces diabetes- and cancer-related pathological events have not been fully unraveled. Hence, CUR is the subject of intensive research in the fields Diabetology and Oncology as a potential candidate in the treatment of both T2DM and cancer, particularly since current therapeutic options for their treatment are not satisfactory in clinics. In this review, we summarize the recent progress made on the molecular targets and pathways involved in antidiabetic and anticancer activities of CUR that are responsible for its beneficial health effects.

  9. Reconstruction of ancestral metabolic enzymes reveals molecular mechanisms underlying evolutionary innovation through gene duplication.

    Directory of Open Access Journals (Sweden)

    Karin Voordeckers

    Full Text Available Gene duplications are believed to facilitate evolutionary innovation. However, the mechanisms shaping the fate of duplicated genes remain heavily debated because the molecular processes and evolutionary forces involved are difficult to reconstruct. Here, we study a large family of fungal glucosidase genes that underwent several duplication events. We reconstruct all key ancestral enzymes and show that the very first preduplication enzyme was primarily active on maltose-like substrates, with trace activity for isomaltose-like sugars. Structural analysis and activity measurements on resurrected and present-day enzymes suggest that both activities cannot be fully optimized in a single enzyme. However, gene duplications repeatedly spawned daughter genes in which mutations optimized either isomaltase or maltase activity. Interestingly, similar shifts in enzyme activity were reached multiple times via different evolutionary routes. Together, our results provide a detailed picture of the molecular mechanisms that drove divergence of these duplicated enzymes and show that whereas the classic models of dosage, sub-, and neofunctionalization are helpful to conceptualize the implications of gene duplication, the three mechanisms co-occur and intertwine.

  10. Assessment on the Vulnerability of Mangrove Ecosystems in the Guangxi Coastal Zone under Sea Level Rise

    Science.gov (United States)

    Li, S.; Ge, Z.; Zhang, L.

    2013-12-01

    Sea level rise caused by global climate change will have significant impacts on coastal zone. The mangrove ecosystems occur at the intertidal zone in tropical and subtropical coasts and are particularly sensitive to sea level rise. To study the responses of mangrove ecosystems to sea level rise, assess the impacts of sea level rise on mangrove ecosystem and formulate the feasible and practical mitigation strategies are the important prerequisites for securing the coastal ecosystems. In this research, taking the mangrove ecosystems in the coastal zone of Guangxi province, China as a case study, the potential impacts of sea level rise on the mangrove ecosystems were analyzed by adopting the SPRC (Source-Pathway- Receptor- Consequence) model. An index system for vulnerability assessment on coastal mangrove ecosystems under sea level rise was worked out, in which rate of sea level rise, subsidence/uplift rate, habitat elevation, daily inundation duration, intertidal slope and sedimentation rate were selected as the key indicators according to the IPCC definition of vulnerability, i.e. the aspects of exposure, sensitivity and adaptation. A quantitatively spatial assessment method based on the GIS platform was established by quantifying each indicator, calculating the vulnerability index and grading the vulnerability. The vulnerability assessment based on the sea-level rise rates of the present trend and IPCC A1F1 scenario were performed for three sets of projections of short-term (2030s), mid-term (2050s) and long-term (2100s). The results showed at the present trend of sea level rise rate of 0.27 cm/a, the mangrove ecosystems in the coastal zone of Guangxi was within the EVI score of 0 in the projections of 2030s, 2050s and 2100s, respectively. As the sedimentation and land uplift could offset the rate of sea level rise and the impact of sea level rise on habitats/species of mangrove ecosystems was negligible. While at the A1F1 scenario with a sea level rise rate of 0

  11. Importance of 'blue' photon levels for lettuce seedlings grown under red-light-emitting diodes

    Science.gov (United States)

    Hoenecke, M. E.; Bula, R. J.; Tibbitts, T. W.

    1992-01-01

    Light-emitting diodes (LEDs) with high-intensity output are being studied as a photosynthetic light source for plants. High-output LEDs have peak emission at approximately 660 nm concentrated in a waveband of +/- 30 nm. Lettuce (Lactuca sativa Grand Rapids') seedlings developed extended hypocotyls and elongated cotyledons when grown under these LEDs as a sole source of irradiance. This extension and elongation was prevented when the red LED radiation was supplemented with more than 15 micromoles m-2 s-1 of 400- to 500-nm photons from blue fluorescent lamps. Blue radiation effects were independent of the photon level of the red radiation.

  12. Radiation induced deep level defects in bipolar junction transistors under various bias conditions

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chaoming; Yang, Jianqun [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Li, Xingji, E-mail: lxj0218@hit.edu.cn [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Ma, Guoliang [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Xiao, Liyi [Department of Astronautics, Harbin Institute of Technology, Harbin 150001 (China); Bollmann, Joachim [Institute of Electronics and Sensor Materials, TU Bergakademie Freiberg, 71691 (Germany)

    2015-12-15

    Bipolar junction transistor (BJT) is sensitive to ionization and displacement radiation effects in space. In this paper, 35 MeV Si ions were used as irradiation source to research the radiation damage on NPN and PNP bipolar transistors. The changing of electrical parameters of transistors was in situ measured with increasing irradiation fluence of 35 MeV Si ions. Using deep level transient spectroscopy (DLTS), defects in the bipolar junction transistors under various bias conditions are measured after irradiation. Based on the in situ electrical measurement and DLTS spectra, it is clearly that the bias conditions can affect the concentration of deep level defects, and the radiation damage induced by heavy ions.

  13. Design scope and level for standard design certification under a two step licensing process

    Energy Technology Data Exchange (ETDEWEB)

    Huh, Chang Wook; Suh, Nam Duk [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2012-08-15

    A small integral reactor SMART (System Integrated Modular Advanced ReacTor), being developed in Korea since late 1990s and targeted to obtaining a standard design approval by the end of 2011, is introduced. The design scope and level for design certification (DC) is well described in the U.S. NRC SECY documents published the early 1990s. However, the documents are valid for a one-step licensing process called a combined operating license (COL) by the U.S. NRC, while Korea still uses a two-step licensing process. Thus, referencing the concept of the SECY documents, we have established the design scope and level for the SMART DC using the contexts of the standard review plan (SRP). Some examples of the results and issues raised during our review are briefly presented in this paper. The same methodology will be applied to other types of reactor under development in Korea, such as future VHTR reactors.

  14. Radiation induced deep level defects in bipolar junction transistors under various bias conditions

    Science.gov (United States)

    Liu, Chaoming; Yang, Jianqun; Li, Xingji; Ma, Guoliang; Xiao, Liyi; Bollmann, Joachim

    2015-12-01

    Bipolar junction transistor (BJT) is sensitive to ionization and displacement radiation effects in space. In this paper, 35 MeV Si ions were used as irradiation source to research the radiation damage on NPN and PNP bipolar transistors. The changing of electrical parameters of transistors was in situ measured with increasing irradiation fluence of 35 MeV Si ions. Using deep level transient spectroscopy (DLTS), defects in the bipolar junction transistors under various bias conditions are measured after irradiation. Based on the in situ electrical measurement and DLTS spectra, it is clearly that the bias conditions can affect the concentration of deep level defects, and the radiation damage induced by heavy ions.

  15. Molecular Processes Studied at a Single-Molecule Level Using DNA Origami Nanostructures and Atomic Force Microscopy

    Directory of Open Access Journals (Sweden)

    Ilko Bald

    2014-09-01

    Full Text Available DNA origami nanostructures allow for the arrangement of different functionalities such as proteins, specific DNA structures, nanoparticles, and various chemical modifications with unprecedented precision. The arranged functional entities can be visualized by atomic force microscopy (AFM which enables the study of molecular processes at a single-molecular level. Examples comprise the investigation of chemical reactions, electron-induced bond breaking, enzymatic binding and cleavage events, and conformational transitions in DNA. In this paper, we provide an overview of the advances achieved in the field of single-molecule investigations by applying atomic force microscopy to functionalized DNA origami substrates.

  16. Coastal flood damage and adaptation costs under 21st century sea-level rise.

    Science.gov (United States)

    Hinkel, Jochen; Lincke, Daniel; Vafeidis, Athanasios T; Perrette, Mahé; Nicholls, Robert James; Tol, Richard S J; Marzeion, Ben; Fettweis, Xavier; Ionescu, Cezar; Levermann, Anders

    2014-03-04

    Coastal flood damage and adaptation costs under 21st century sea-level rise are assessed on a global scale taking into account a wide range of uncertainties in continental topography data, population data, protection strategies, socioeconomic development and sea-level rise. Uncertainty in global mean and regional sea level was derived from four different climate models from the Coupled Model Intercomparison Project Phase 5, each combined with three land-ice scenarios based on the published range of contributions from ice sheets and glaciers. Without adaptation, 0.2-4.6% of global population is expected to be flooded annually in 2100 under 25-123 cm of global mean sea-level rise, with expected annual losses of 0.3-9.3% of global gross domestic product. Damages of this magnitude are very unlikely to be tolerated by society and adaptation will be widespread. The global costs of protecting the coast with dikes are significant with annual investment and maintenance costs of US$ 12-71 billion in 2100, but much smaller than the global cost of avoided damages even without accounting for indirect costs of damage to regional production supply. Flood damages by the end of this century are much more sensitive to the applied protection strategy than to variations in climate and socioeconomic scenarios as well as in physical data sources (topography and climate model). Our results emphasize the central role of long-term coastal adaptation strategies. These should also take into account that protecting large parts of the developed coast increases the risk of catastrophic consequences in the case of defense failure.

  17. Molecular mechanisms underlying the enhanced analgesic effect of oxycodone compared to morphine in chemotherapy-induced neuropathic pain.

    Directory of Open Access Journals (Sweden)

    Karine Thibault

    Full Text Available Oxycodone is a μ-opioid receptor agonist, used for the treatment of a large variety of painful disorders. Several studies have reported that oxycodone is a more potent pain reliever than morphine, and that it improves the quality of life of patients. However, the neurobiological mechanisms underlying the therapeutic action of these two opioids are only partially understood. The aim of this study was to define the molecular changes underlying the long-lasting analgesic effects of oxycodone and morphine in an animal model of peripheral neuropathy induced by a chemotherapic agent, vincristine. Using a behavioural approach, we show that oxycodone maintains an optimal analgesic effect after chronic treatment, whereas the effect of morphine dies down. In addition, using DNA microarray technology on dorsal root ganglia, we provide evidence that the long-term analgesic effect of oxycodone is due to an up-regulation in GABAB receptor expression in sensory neurons. These receptors are transported to their central terminals within the dorsal horn, and subsequently reinforce a presynaptic inhibition, since only the long-lasting (and not acute anti-hyperalgesic effect of oxycodone was abolished by intrathecal administration of a GABAB receptor antagonist; in contrast, the morphine effect was unaffected. Our study demonstrates that the GABAB receptor is functionally required for the alleviating effect of oxycodone in neuropathic pain condition, thus providing new insight into the molecular mechanisms underlying the sustained analgesic action of oxycodone.

  18. Molecular mechanisms underlying the enhanced analgesic effect of oxycodone compared to morphine in chemotherapy-induced neuropathic pain.

    Science.gov (United States)

    Thibault, Karine; Calvino, Bernard; Rivals, Isabelle; Marchand, Fabien; Dubacq, Sophie; McMahon, Stephen B; Pezet, Sophie

    2014-01-01

    Oxycodone is a μ-opioid receptor agonist, used for the treatment of a large variety of painful disorders. Several studies have reported that oxycodone is a more potent pain reliever than morphine, and that it improves the quality of life of patients. However, the neurobiological mechanisms underlying the therapeutic action of these two opioids are only partially understood. The aim of this study was to define the molecular changes underlying the long-lasting analgesic effects of oxycodone and morphine in an animal model of peripheral neuropathy induced by a chemotherapic agent, vincristine. Using a behavioural approach, we show that oxycodone maintains an optimal analgesic effect after chronic treatment, whereas the effect of morphine dies down. In addition, using DNA microarray technology on dorsal root ganglia, we provide evidence that the long-term analgesic effect of oxycodone is due to an up-regulation in GABAB receptor expression in sensory neurons. These receptors are transported to their central terminals within the dorsal horn, and subsequently reinforce a presynaptic inhibition, since only the long-lasting (and not acute) anti-hyperalgesic effect of oxycodone was abolished by intrathecal administration of a GABAB receptor antagonist; in contrast, the morphine effect was unaffected. Our study demonstrates that the GABAB receptor is functionally required for the alleviating effect of oxycodone in neuropathic pain condition, thus providing new insight into the molecular mechanisms underlying the sustained analgesic action of oxycodone.

  19. Development of quinoxaline 1, 4-dioxides resistance in Escherichia coli and molecular change under resistance selection.

    Directory of Open Access Journals (Sweden)

    Wentao Guo

    Full Text Available Quinoxaline 1, 4-dioxides (QdNOs has been used in animals as antimicrobial agents and growth promoters for decades. However, the resistance to QdNOs in pathogenic bacteria raises worldwide concern but it is barely known. To explore the molecular mechanism involved in development of QdNOs resistance in Escherichia coli, 6 strains selected by QdNOs in vitro and 21 strains isolated from QdNOs-used swine farm were subjected to MIC determination and PCR amplification of oqxA gene. A conjugative transfer was carried out to evaluate the transfer risk of QdNOs resistant determinant. Furthermore, the transcriptional profile of a QdNOs-resistant E. coli (79O4-2 selected in vitro with its parent strain 79-161 was assayed with a prokaryotic suppression subtractive hybridization (SSH PCR cDNA subtraction. The result showed that more than 95% (20/21 clinical isolates were oqxA positive, while all the 6 induced QdNOs-resistant strains carried no oqxA gene and exhibited low frequency of conjugation. 44 fragments were identified by SSH PCR subtraction in the QdNOs-resistant strain 79O4-2. 18 cDNAs were involved in biosynthesis of Fe-S cluster (narH, protein (rpoA, trmD, truA, glyS, ileS, rplFCX, rpsH, fusA, lipoate (lipA, lipid A (lpxC, trehalose (otsA, CTP(pyrG and others molecular. The 11 cDNAs were related to metabolism or degradation of glycolysis (gpmA and pgi and proteins (clpX, clpA, pepN and fkpB. The atpADG and ubiB genes were associated with ATP biosynthesis and electron transport chain. The pathway of the functional genes revealed that E. coli may adapt the stress generated by QdNOs or develop specific QdNOs-resistance by activation of antioxidative agents biosynthesis (lipoate and trehalose, protein biosynthesis, glycolysis and oxidative phosphorylation. This study initially reveals the possible molecular mechanism involved in the development of QdNOs-resistance in E. coli, providing with novel insights in prediction and assessment of the emergency

  20. The effect of gamma radiation on yield of Arabic Abiad barley under different nitrogen levels

    International Nuclear Information System (INIS)

    Khalifa, Kh.

    1994-03-01

    A field experiment was carried out at ACSAD research station in Deir-Ezzor district during two seasons 1987/88 and 1988/89 on medium-heavy textured soil. Arabic Abiad barley variety was used under irrigated conditions. The aim was to study the effect of five doses of gamma rays 0, 5, 10, 15 and 20 Gray and four levels of nitrogen 0, 50, 80, and 100 Kg N/ha, and their interactions on yield. The results showed that the irradiation doses and nitrogen rates significantly increased barley's grain and straw yield compared to control. All doses of gamma radiation significantly increased grain and straw yield. While nitrogen levels 50, 80 and 100 Kg N/ha lead to grain yield increases by 24.8, 32.0, and 29.9% and straw yield increases 19.2, 17.0 and 3.1% respectively. The highest positive interaction was observed between 5-20 Gy dose and 50 Kg N/Ha nitrogen levels. In general, the rate of yield increase was reduced as the irradiation doses and nitrogen levels were increased. (author). 34 refs., 19 tabs

  1. [Pathophysiology of neuropathic pain: molecular mechanisms underlying central sensitization in the dorsal horn in neuropathic pain].

    Science.gov (United States)

    Yamanaka, Hiroki; Noguchi, Koichi

    2012-11-01

    Neuropathic pain syndromes are clinically characterized by spontaneous pain and evoked pain (hyperalgesia and allodynia). The optimal treatment approach for neuropathic pain is still under development because of the complex pathological mechanisms underlying this type of pain. The spinal cord is an important gateway thorough which peripheral pain signals are transmitted to the brain, and sensitization of the spinal neurons is one of the important mechanisms underlying neuropathic pain. Central sensitization represents enhancement of the function of neuronal circuits in nociceptive pathways and is a manifestation of the remarkable plasticity of the somatosensory nervous system after nerve injury. This review highlights the pathological features of central sensitization, which develops because of (1) injury-induced abnormal inputs from primary afferents, (2) increase in the excitability of dorsal horn neurons, and (3) activated glial cell-derived signals.

  2. Electronic processes in molecular dynamics simulations of nanoscale metal tips under electric fields

    CERN Document Server

    Parviainen, S; Djurabekova, F; Timko, H

    2011-01-01

    Electronic effects play a crucial role in the temperature evolution of metal parts which have electric currents running through them. The increase in temperature due to resistive heating can cause the melting of metal nanoscale wires creating damage in electric circuits. Likewise, electric currents are also present in sharp features on metal surfaces exposed to high electric fields. The destruction of such tips can lead to vacuum arcs, supplying the neutral species to build up plasma over the surface. To follow the temperature evolution caused by electric currents in such a tip, we developed a new model, based on an existing molecular dynamics code, to include resistive heating and electronic thermal conduction. The results given by the new simulation model are in good agreement with analytical predictions. (C) 2011 Published by Elsevier B.V.

  3. Magnetic fingerprint of individual Fe4 molecular magnets under compression by a scanning tunnelling microscope

    Science.gov (United States)

    Burgess, Jacob A. J.; Malavolti, Luigi; Lanzilotto, Valeria; Mannini, Matteo; Yan, Shichao; Ninova, Silviya; Totti, Federico; Rolf-Pissarczyk, Steffen; Cornia, Andrea; Sessoli, Roberta; Loth, Sebastian

    2015-09-01

    Single-molecule magnets (SMMs) present a promising avenue to develop spintronic technologies. Addressing individual molecules with electrical leads in SMM-based spintronic devices remains a ubiquitous challenge: interactions with metallic electrodes can drastically modify the SMM's properties by charge transfer or through changes in the molecular structure. Here, we probe electrical transport through individual Fe4 SMMs using a scanning tunnelling microscope at 0.5 K. Correlation of topographic and spectroscopic information permits identification of the spin excitation fingerprint of intact Fe4 molecules. Building from this, we find that the exchange coupling strength within the molecule's magnetic core is significantly enhanced. First-principles calculations support the conclusion that this is the result of confinement of the molecule in the two-contact junction formed by the microscope tip and the sample surface.

  4. Genetic and Molecular Mechanisms Underlying Symbiotic Specificity in Legume-Rhizobium Interactions

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2018-03-01

    Full Text Available Legumes are able to form a symbiotic relationship with nitrogen-fixing soil bacteria called rhizobia. The result of this symbiosis is to form nodules on the plant root, within which the bacteria can convert atmospheric nitrogen into ammonia that can be used by the plant. Establishment of a successful symbiosis requires the two symbiotic partners to be compatible with each other throughout the process of symbiotic development. However, incompatibility frequently occurs, such that a bacterial strain is unable to nodulate a particular host plant or forms nodules that are incapable of fixing nitrogen. Genetic and molecular mechanisms that regulate symbiotic specificity are diverse, involving a wide range of host and bacterial genes/signals with various modes of action. In this review, we will provide an update on our current knowledge of how the recognition specificity has evolved in the context of symbiosis signaling and plant immunity.

  5. Molecular dynamics simulation of the rheological and dynamical properties of a model alkane fluid under confinement

    International Nuclear Information System (INIS)

    Cui, S.T.; Cummings, P.T.; Cochran, H.D.

    1999-01-01

    We study the effect of wall endash fluid interactions on the state conditions and the effective properties of a model dodecane fluid confined between parallel solid walls. A significant increase in the effective density of the confined fluid is observed with increasing strength of the wall endash fluid interaction. The effect of the wall endash fluid interaction on the rotational relaxation and diffusional relaxation of the fluid is seen in the significant slowing down of the relaxation with increasing wall endash fluid interaction strength. The difference between the confined fluid and the three-dimensional bulk fluid is demonstrated by the strong anisotropy of the dynamical properties, the molecular rotation, and self-diffusion. The viscosity of the confined fluid shows a large difference between weak and strong wall endash fluid interactions, and a significant difference from bulk fluid at low shear rate. copyright 1999 American Institute of Physics

  6. Molecular mechanisms underlying radio-induced fibro-genic differentiation and fibrosis targeted therapies

    International Nuclear Information System (INIS)

    Bourgier, C.

    2008-01-01

    Intestinal complications after radiotherapy are caused by transmural fibrosis (RIF) that impaired the quality of life of cancer patient survivors and considered permanent and irreversible until recently but recent molecular characterization of RIF offered new targeted opportunities for the development of anti-fibrotic therapies. In this thesis work, we identified activation of the Rho/ROCK pathway which is involved in the persistence of fibro-genic signals. In addition, among the new anti-fibrotic targeted therapies, we asked whether specific inhibition of Rho pathway, by Pravastatin could elicit anti-fibrotic action. Therefore, the therapeutic relevance of pravastatin as anti-fibrotic strategy was validated using two different models of intestinal and lung fibrosis. As statins are safe and well tolerated compounds, phase II clinical trial is envisioned within the next months to reverse established fibrosis after radiotherapy. (author)

  7. Dissecting the molecular mechanism underlying the intimate relationship between cellulose microfibrils and cortical microtubules

    Directory of Open Access Journals (Sweden)

    Lei eLei

    2014-03-01

    Full Text Available A central question in plant cell development is how the cell wall determines directional cell expansion and therefore the final shape of the cell. As the major load-bearing component of the cell wall, cellulose microfibrils are laid down transversely to the axis of elongation, thus forming a spring-like structure that reinforces the cell laterally and while favoring longitudinal expansion in most growing cells. Mounting evidence suggests that cortical microtubules organize the deposition of cellulose microfibrils, but the precise molecular mechanisms linking microtubules to cellulose organization have remained unclear until the recent discovery of CSI1, a linker protein between the cortical microtubules and the cellulose biosynthesizing machinery. In this review, we will focus on the intimate relationship between cellulose microfibrils and cortical microtubules, in particular, we will discuss microtubule arrangement and cell wall architecture, the linkage between cellulose synthase complexes and microtubules, and the feedback mechanisms between cell wall and microtubules.

  8. Molecular mechanisms underlying the interaction of protein phosphatase-1c with ASPP proteins.

    Science.gov (United States)

    Skene-Arnold, Tamara D; Luu, Hue Anh; Uhrig, R Glen; De Wever, Veerle; Nimick, Mhairi; Maynes, Jason; Fong, Andrea; James, Michael N G; Trinkle-Mulcahy, Laura; Moorhead, Greg B; Holmes, Charles F B

    2013-02-01

    The serine/threonine PP-1c (protein phosphatase-1 catalytic subunit) is regulated by association with multiple regulatory subunits. Human ASPPs (apoptosis-stimulating proteins of p53) comprise three family members: ASPP1, ASPP2 and iASPP (inhibitory ASPP), which is uniquely overexpressed in many cancers. While ASPP2 and iASPP are known to bind PP-1c, we now identify novel and distinct molecular interactions that allow all three ASPPs to bind differentially to PP-1c isoforms and p53. iASPP lacks a PP-1c-binding RVXF motif; however, we show it interacts with PP-1c via a RARL sequence with a Kd value of 26 nM. Molecular modelling and mutagenesis of PP-1c-ASPP protein complexes identified two additional modes of interaction. First, two positively charged residues, Lys260 and Arg261 on PP-1c, interact with all ASPP family members. Secondly, the C-terminus of the PP-1c α, β and γ isoforms contain a type-2 SH3 (Src homology 3) poly-proline motif (PxxPxR), which binds directly to the SH3 domains of ASPP1, ASPP2 and iASPP. In PP-1cγ this comprises residues 309-314 (PVTPPR). When the Px(T)PxR motif is deleted or mutated via insertion of a phosphorylation site mimic (T311D), PP-1c fails to bind to all three ASPP proteins. Overall, we provide the first direct evidence for PP-1c binding via its C-terminus to an SH3 protein domain.

  9. Virtual Atomic and Molecular Data Centre: Level 3 Service and Future Prospects

    Science.gov (United States)

    Dubernet, M. L.; Rixon, G.; Doronin, M.; VAMDC Collaboration

    2015-03-01

    The Virtual Atomic and Molecular Data Centre (VAMDC, http://www.vamdc.eu) is an international Consortium that has created an interoperable e-science infrastructure for the exchange of atomic and molecular data. The VAMDC defines standards for the exchange of atomic and molecular data, develop reference implementation of those standards, deploys registries of internet resources (yellow pages), designs user applications in order to meet the user needs, builds data access layers above databases to provide unified outputs from these databases, cares about asynchronous queries with workflows and connects its infrastructure to the grid. The paper describes the current service deployment of the VAMDC data infrastructure across our registered databases and the key features of the current infrastructure.

  10. Multishell structure formation in Ni nanowire under uniaxial strain along <0 0 1> crystallographic direction: A molecular dynamics simulation

    Energy Technology Data Exchange (ETDEWEB)

    Wang Li, E-mail: wanglihxf@sdu.edu.c [School of Mechanical and Electrical Engineering, Shandong University at Weihai, 180 Wenhuaxi Road, Weihai 264209 (China); Peng Chuanxiao [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Gong Jianhong [School of Mechanical and Electrical Engineering, Shandong University at Weihai, 180 Wenhuaxi Road, Weihai 264209 (China)

    2010-04-01

    Molecular dynamics simulations based upon embedded-atom-method potential are employed to explore the fracture behavior of Ni nanowire along <0 0 1> crystallographic direction at temperature of 300 K. We find the formation of (5,5) multishell structure (MS), which is transformed from (6,5) MS at the necking region of nanowire under the strain rate of 0.02%ps{sup -1}. A reorientation transformation from <0 0 1> to <1 1 0> is first detected before formation of (6,5) MS. The formed (5,5) MS is more stable and can be tensioned longer as lower strain rate is loaded.

  11. Excitation of high energy levels under laser exposure of suspensions of nanoparticles in liquids

    Energy Technology Data Exchange (ETDEWEB)

    Shafeev, G.A. [Wave Research Center of A.M. Prokhorov General Physics Institute, 38, Vavilov Street, 119991 Moscow (Russian Federation)], E-mail: shafeev@kapella.gpi.ru; Simakin, A.V. [Wave Research Center of A.M. Prokhorov General Physics Institute, 38, Vavilov Street, 119991 Moscow (Russian Federation); Bozon-Verduraz, F. [ITODYS, UMR CNRS 7086, Universite Paris 7-Denis Diderot, 2, place Jussieu, 75251 Paris cedex 05 (France); Robert, M. [Laboratoire d' Electrochimie Moleculaire, UMR CNRS 7591, Universite Paris 7 Denis Diderot, 2, place Jussieu, 75251 Paris cedex 05 (France)

    2007-12-15

    Laser exposure of suspensions of nanoparticles in liquids leads to excitation of high energy levels in both liquid and nanoparticle material. The emission spectrum of the colloidal solution under exposure of a suspension metallic nanoparticles in water to radiation of a Nd:YAG laser of a picosecond range of pulse duration is discussed. Excitation of nuclear energy levels and neutron release is experimentally studied on the model system of transmutation of Hg into Au that occurs under exposure of Hg nanodrops suspended in D{sub 2}O. The proposed mechanism involves: (i) emission of X-ray photons by Hg nanoparticles upon laser exposure, leading to neutron release from D{sub 2}O, (ii) initiation of Hg {yields} Au transmutation by the capture of neutrons. The effect of transmutation is more pronounced using {sup 196}Hg isotope instead of Hg of natural isotope composition. The influence of laser pulse duration on the degree of transmutation (from fs through ns range) is discussed.

  12. Arsenate biotransformation by Microcystis aeruginosa under different nitrogen and phosphorus levels.

    Science.gov (United States)

    Che, Feifei; Du, Miaomiao; Yan, Changzhou

    2018-04-01

    The arsenate (As(V)) biotransformation by Microcystis aeruginosa in a medium with different concentrations of nitrogen (N) and phosphorus (P) has been studied under laboratory conditions. When 15μg/L As(V) was added, N and P in the medium showed effective regulation on arsenic (As) metabolism in M. aeruginosa, resulting in significant differences in the algal growth among different N and P treatments. Under 0.2mg/L P treatment, increases in N concentration (4-20mg/L) significantly stimulated the cell growth and therefore indirectly enhanced the production of dimethylarsinic acid (DMA), the main As metabolite, accounting for 71%-79% of the total As in the medium. Meanwhile, 10-20mg/L N treatments accelerated the ability of As metabolization by M. aeruginosa, leading to higher contents of DMA per cell. However, As(V) uptake by M. aeruginosa was significantly impeded by 0.5-1.0mg/L P treatment, resulting in smaller rates of As transformation in M. aeruginosa as well as lower contents of As metabolites in the medium. Our data demonstrated that As(V) transformation by M. aeruginosa was significantly accelerated by increasing N levels, while it was inhibited by increasing P levels. Overall, both P and N play key roles in As(V) biotransformation processes. Copyright © 2017. Published by Elsevier B.V.

  13. Formocresol blood levels in children receiving dental treatment under general anesthesia.

    Science.gov (United States)

    Kahl, Jeffrey; Easton, Jillian; Johnson, Gillian; Zuk, Jeannie; Wilson, Stephen; Galinkin, Jeffrey

    2008-01-01

    The purpose of this study was to determine the presence of formocresol in the plasma of children undergoing oral rehabilitation involving pulp therapy under general anesthesia. Thirty 2- to 6-year-old preschool children were enrolled in the study. Preoperative, intra-operative, and postoperative peripheral venous samples were collected from each child. All samples were analyzed for formaldehyde and cresol levels using gas chromatography with mass spectrometry detection. Eighty-five pulpotomies were performed ranging from 1 to 5 per child. Three hundred twelve blood samples were collected. Analysis revealed that formaldehyde was undetectable above baseline plasma concentration and cresol was undetectable in all samples. Benzyl alcohol (a byproduct of cresol metabolism) was present in all samples except the baseline preoperative samples. Benzyl alcohol concentrations ranged from 0 to 1 mg/ml. Formaldehyde was undetectable above baseline plasma concentration, and cresol was undetectable in subjects receiving pulpotomy treatment under general anesthesia. Benzyl alcohol was detected in the plasma of all subjects receiving pulpotomy treatment. The levels present were far below the Food and Drug Administration's recommended daily allowance. It is unlikely that formocresol, when used in the doses typically employed for a vital pulpotomy procedure, poses any risk to children.

  14. Studies on the growth of penaeid prawns: 1. Length-weight relation and condition factor under different levels of feeding

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, S.R.S.; Iyer, H.K.; Devi, C.B.L.; Kutty, M.K.

    Length-weight relation and earthworm feeding conditions under different levels for @iPenaeus indicus@@ and @iMetapenaeus dobsoni@@ were estimated. Length-weight exponent in both species was unaffected by the feeding levels and the consequent...

  15. An anti-herbivore defense mutualism under elevated CO2 levels

    Energy Technology Data Exchange (ETDEWEB)

    Marks, S.; Lincoln, D.E. (Winthrop Univ., Rock Hill, SC (United States))

    1994-06-01

    Previous studies have shown that insects typically consume more when fed leaf tissue grown under CO2 enrichment, but with few negative effects on growth. On the other hand, Lepidopteran larvae fed tissue infected with Balansiae fungal endophytes (which produce toxic alkaloids) typically eat less but suffer negative effects on growth and survival. This study was carried out to see how these two factors would interact to affect consumption and growth of Fall Armyworm larvae (Spodoptera frugiperda). Infected and uninfected ramets of a single genotype of tall fescue (Festuca arundinacea) were grown under CO2 concentrations of 400 and 700 ul/L. Larvae had increased relative growth in the high CO2 treatment, but decreased growth when fed infected tissue. Relative consumption of leaf tissue was greater in the high CO2 treatment, but was not effected by infection. CO2 level, infection, and their interaction all significantly reduced the efficiency of conversion of food ingested (ECI). It appears that tall fescue may not be as well defended against herbivores under CO2 enrichment, although insects may still avoid and be negatively effected by endophyte infected plants.

  16. Capacity Payments in Restructured Markets under Low and High Penetration Levels of Renewable Energy

    Energy Technology Data Exchange (ETDEWEB)

    Jenkin, Thomas [National Renewable Energy Lab. (NREL), Golden, CO (United States); Beiter, Philipp [National Renewable Energy Lab. (NREL), Golden, CO (United States); Margolis, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-02-11

    There is considerable debate about the degree to which restructured markets perform successfully in their use of capacity markets. In providing appropriate incentives for new and existing generation to meet reliability requirements, a variety of capacity market designs have developed across RTOs and ISOs in the United States and internationally. Growing levels of variable renewable energy (VRE) resources arguably create new challenges for capacity market designs, because VREs suppress energy prices while providing relatively little capacity, with these effects increase with VRE penetration. The purpose of this report is threefold. First, we provide a brief outline of the purpose and design of various capacity markets under consideration using variable resource requirement (VRR) demand curves. Second, we discuss some of the main challenges raised in existing literature and a set of interviews that we conducted with market participants, regulators, and observers, including where there substantive differences in opinion. Third, we consider some of the challenges that may be specific to higher penetration levels of VRE. While the well known 'merit order' effect from VRE can be expected to suppress wholesale energy prices and revenue, this may be partly mitigated by increased capacity payments and the greater importance of AS payments for flexible capacity. The potential for greater reliance on capacity markets for generator revenues may amplify any inefficiency and costs associated with capacity price volatility and other suboptimal market design choices. Regulatory intervention to ensure adequate capacity payments and ancillary service revenue may become more prevalent under current market designs as the timescale for market signals shifts increasingly from near term (e.g., day-ahead in wholesale electricity markets) to longer term (annual intervals in capacity markets). Our review and discussion with market participants suggest substantive challenges may

  17. Multi-Component Molecular-Level Body Composition Reference Methods: Evolving Concepts and Future Directions

    Science.gov (United States)

    Heymsfield, Steven B.; Ebbeling, Cara B.; Zheng, Jolene; Pietrobelli, Angelo; Strauss, Boyd J.; Silva, Analiza M.; Ludwig, David S.

    2015-01-01

    Excess adiposity is the main phenotypic feature that defines human obesity and that plays a pathophysiological role in most chronic diseases. Measuring the amount of fat mass present is thus a central aspect of studying obesity at the individual and population levels. Nevertheless, a consensus is lacking among investigators on a single accepted “reference” approach for quantifying fat mass in vivo. While the research community generally relies on the multicomponent body-volume class of “reference” models for quantifying fat mass, no definable guide discerns among different applied equations for partitioning the four (fat, water, protein, and mineral mass) or more quantified components, standardizes “adjustment” or measurement system approaches for model-required labeled water dilution volumes and bone mineral mass estimates, or firmly establishes the body temperature at which model physical properties are assumed. The resulting differing reference strategies for quantifying body composition in vivo leads to small but under some circumstances important differences in the amount of measured body fat. Recent technological advances highlight opportunities to expand model applications to new subject groups and measured components such as total body protein. The current report reviews the historical evolution of multicomponent body volume-based methods in the context of prevailing uncertainties and future potential. PMID:25645009

  18. Differentiation of molecular chain entanglement structure through laser Raman spectrum measurement of High strength PET fibers under stress

    Science.gov (United States)

    Go, D.; Takarada, W.; Kikutani, T.

    2017-10-01

    The aim of this study was to investigate the mechanism for the improvement of mechanical properties of poly(ethylene terephthalate) (PET) fibers based on the concept of controlling the state of molecular entanglement. For this purpose, five different PET fibers were prepared through either the conventional melt spinning and drawing/annealing process or the high-speed melt spinning process. In both cases, the melt spinning process was designed so as to realize different Deborah number conditions. The prepared fibers were subjected to the laser Raman spectroscopy measurement and the characteristics of the scattering peak at around 1616 cm-1, which corresponds to the C-C/C=C stretching mode of the aromatic ring in the main chain, were investigated in detail. It was revealed that the fibers drawn and annealed after the melt spinning process of lower Deborah number showed higher tensile strength as well as lower value of full width at half maximum (FWHM) in the laser Raman spectrum. Narrow FWHM was considered to represent the homogeneous state of entanglement structure, which may lead to the higher strength and toughness of fibers because individual molecular chains tend to bare similar level of tensile stress when the fiber is stretched. In case of high-speed spun fibers prepared with a high Deborah number condition, the FWHM was narrow presumably because much lower tensile stress in comparison with the drawing/annealing process was applied when the fiber structure was developed, however the value increased significantly upon applying tensile load to the fibers during the laser Raman spectrum measurement. From these results, it was concluded that the Laser Raman spectroscopy could differentiate molecular chain entanglement structure of various fiber samples, in that low FWHM, which corresponds to either homogeneous state of molecular entanglement or lower level of mean residual stress, and small increase of FWTH upon applying tensile stress are considered to be the key

  19. Noncanonical structures and their thermodynamics of DNA and RNA under molecular crowding: beyond the Watson-Crick double helix.

    Science.gov (United States)

    Sugimoto, Naoki

    2014-01-01

    How does molecular crowding affect the stability of nucleic acid structures inside cells? Water is the major solvent component in living cells, and the properties of water in the highly crowded media inside cells differ from that in buffered solution. As it is difficult to measure the thermodynamic behavior of nucleic acids in cells directly and quantitatively, we recently developed a cell-mimicking system using cosolutes as crowding reagents. The influences of molecular crowding on the structures and thermodynamics of various nucleic acid sequences have been reported. In this chapter, we discuss how the structures and thermodynamic properties of nucleic acids differ under various conditions such as highly crowded environments, compartment environments, and in the presence of ionic liquids, and the major determinants of the crowding effects on nucleic acids are discussed. The effects of molecular crowding on the activities of ribozymes and riboswitches on noncanonical structures of DNA- and RNA-like quadruplexes that play important roles in transcription and translation are also described. © 2014 Elsevier Inc. All rights reserved.

  20. [Variations of soil fertility level in red soil region under long-term fertilization].

    Science.gov (United States)

    Yu, Han-qing; Xu, Ming-gang; Lü, Jia-long; Bao, Yao-xian; Sun, Nan; Gao, Ju-sheng

    2010-07-01

    Based on the long-term (1982-2007) field experiment of "anthropogenic mellowing of raw soil" at the Qiyang red soil experimental station under Chinese Academy of Agricultural Sciences, and by using numerical theory, this paper studied the variations of the fertility level of granite red soil, quaternary red soil, and purple sandy shale soil under six fertilization patterns. The fertilization patterns included non-fertilization (CK), straw-returning without fertilizers (CKR), chemical fertilization (NPK), NPK plus straw-return (NPKR), rice straw application (M), and M plus straw-return (MR). The soil integrated fertility index (IFI) was significantly positively correlated with relative crop yield, and could better indicate soil fertility level. The IFI values of the three soils all were in the order of NPK, NPKR > M, MR > CK, CKR, with the highest value in treatment NPKR (0.77, 0.71, and 0.71 for granite red soil, quaternary red soil, and purple sandy shale soil, respectively). Comparing with that in the treatments of no straw-return, the IFI value in the treatments of straw return was increased by 6.72%-18.83%. A turning point of the IFI for all the three soils was observed at about 7 years of anthropogenic mellowing, and the annual increasing rate of the IFI was in the sequence of purple sandy shale soil (0.016 a(-1)) > quaternary red clay soil (0.011 a(-1)) > granite red soil (0.006 a(-1)). It was suggested that a combined application of organic and chemical fertilizers and/or straw return could be an effective and fast measure to enhance the soil fertility level in red soil region.

  1. Nutritional Proteomics: Investigating molecular mechanisms underlying the health beneficial effect of functional foods

    Directory of Open Access Journals (Sweden)

    Yusuke Kawashima

    2013-07-01

    Full Text Available ABSTRACTObjective: We introduce a new technical and conceptual term “nutritional proteomics” by identifying and quantifying the proteins and their changes in a certain organ or tissue dependent on the food intake by utilizing a mass spectrometry-based proteomics technique.Purpose: Food intake is essentially important for every life on earth to sustain the physical as well as mental functions. The outcome of food intake will be manifested in the health state and its dysfunction. The molecular information about the protein expression change caused by diets will assist us to understand the significance of functional foods. We wish to develop nutritional proteomics to promote a new area in functional food studies for a better understanding of the role of functional foods in health and disease.Methods: We chose two classes of food ingredients to show the feasibility of nutritional proteomics, omega-3 polyunsaturated fatty acids and omega-6 polyunsaturated fatty acids both of which are involved in the inflammation/anti-inflammation axis. Each class of the polyunsaturated fatty acids was mixed in mouse chow respectively. The liver tissue of mice fed with omega-3 diet or omega-3 diet was analyzed by the state-of-the-art shotgun proteomics using nano-HPLC-ESI-MS/MS. The data were analyzed by the number of differentially expressed proteins that were guaranteed by 1% false discovery rate for protein identification and by the statistical significance of variance evaluated by p-value in two-tailed distribution analysis better than 0.05 (n=4. The differential pattern of protein expression was characterized with Gene Ontology designation.Results: The data analysis of the shotgun nutritional proteomics identified 2,810 proteins that are validated with 1% FDR. Among these 2,810 proteins, 125 were characterized with statistical significance of variance (p<0.05; n=4 between the omega-3 diet and the omega-6 diet by twotailed distribution analysis. The results

  2. Noise Assisted Directed Motion at the Molecular Level - 1 -R-ES ...

    Indian Academy of Sciences (India)

    [6] F J iilicher, A Ajdari and J Prost, Modeling molecular motors, Rev. Mod. Phys., Vol. 69, p. 1269,1997. [7] P Reimann, Brownian motors: noisy transport far from equilibrium,. Physics Reports, Vol. 361, p. 57,2002. [8] AM Jayannavar, cond-mat. 0107079. [9] ForParrondo's games, see G P Harmer and D Abbott, Nature, Vol.

  3. Dietary factors associated with plasma high molecular weight and total adiponectin levels in apparently healthy women

    NARCIS (Netherlands)

    Yannakoulia, Mary; Yiannakouris, Nikos; Melistas, Labros; Fappa, Evaggelia; Vidra, Nikoletta; Kontogianni, Meropi D; Mantzoros, Christos S

    2008-01-01

    OBJECTIVE: Our aim was to investigate associations between dietary factors and high molecular weight (HMW) as well as total adiponectin in a sample of apparently healthy adult Mediterranean women. DESIGN AND METHODS: Two hundred and twenty women were enrolled in this study. Anthropometric and body

  4. Differences in gait pattern between the elderly and the young during level walking under low illumination.

    Science.gov (United States)

    Choi, Jin-Seung; Kang, Dong-Won; Shin, Yoon-Ho; Tack, Gye-Rae

    2014-01-01

    The purpose of this study was to compare changes in the gait pattern between the elderly and young during level (i.e., even surface) walking under low illumination. Vision during walking plays a role in avoiding obstacles and uneven surfaces, as well as an important role in the proactive control of dynamic stability and route planning for level walking. Fourteen elderly and fourteen young male subjects walked on a 7 m walkway with two illumination conditions using self-selected walking speed: walking with normal (>300 lux) and low illumination (gait pattern between two illumination conditions and ages. During walking with low illumination, walking speed and stance phase ratio of the young decreased, and toe clearance of the young increased. However, there was no difference in these variables due to low illumination in the elderly subjects. Despite level walking conditions, there were some differences in gait pattern between the young and the elderly due to illumination conditions. This implies that the young showed a more positive change of gait pattern, due to low illumination, than that of the elderly. In this respect, further study is necessary to identify differences between the young and the elderly, when they walk on an uneven or obstacle walkway with low illumination.

  5. Evolution of nitrate level in green lettuce conventional grown under natural conditions and aquaponic system

    Directory of Open Access Journals (Sweden)

    Flavius Blidariu

    2013-05-01

    Full Text Available Aquaponics integrates growing plants without soil technology with aquaculture, having an important role in recovery of nutrients from effluents. The research aimed to evaluate nitrates level in lettuce (Lactuca sativa conventional grown under natural conditions and in integrated aquaponic system with a recirculated aquaculture system designed for pikeperch growth (Sander lucioperca. Conventional production (54 plants has been obtained in the field without fertilizer or pesticide management. Aquaponics productions (54 plants/production had ponds effluents as a nutritional support from the breeding of pikeperch, tanks were arranged with 255 numbers of pikeperch, each tank of 85 individuals, with a total of fish biomass of 30.76 kg. Fish individual body weight in the experiment was between 66 and 238 grams with an average of 120. 69 g. Chemical analyses were carried out to determine the level of nitrates in 5 plants grown in aquaponic system and respectively, conventional technology. The results have shown that the nitrate level is higher in the salad obtained from the aquaponic system than in conventional technology, however not exceeding the maximum permitted limits..

  6. Cotton Defense Induction Patterns Under Spatially, Temporally and Quantitatively Varying Herbivory Levels.

    Science.gov (United States)

    Eisenring, Michael; Meissle, Michael; Hagenbucher, Steffen; Naranjo, Steven E; Wettstein, Felix; Romeis, Jörg

    2017-01-01

    In its defense against herbivores, cotton ( Gossypium sp.) relies in part on the production of a set of inducible, non-volatile terpenoids. Under uniform damage levels, in planta allocation of induced cotton terpenoids has been found to be highest in youngest leaves, supporting assumptions of the optimal defense theory (ODT) which predicts that plants allocate defense compounds to tissues depending on their value and the likelihood of herbivore attack. However, our knowledge is limited on how varying, and thus more realistic, damage levels might affect cotton defense organization. We hypothesized that the allocation of terpenoids and densities of terpenoid-storing glands in leaves aligns with assumptions of the ODT, even when plants are subjected to temporally, spatially and quantitatively varying caterpillar ( Heliothis virescens ) damage. As expected, cotton plants allocated most of their defenses to their youngest leaves regardless of damage location. However, defense induction in older leaves varied with damage location. For at least 14 days after damage treatments ended, plants reallocated defense resources from previously young leaves to newly developed leaves. Furthermore, we observed a positive hyperbolic relationship between leaf damage area and both terpenoid concentrations and gland densities, indicating that cotton plants can fine-tune defense allocation. Although it appears that factors like vascular constraints and chemical properties of individual defense compounds can affect defense levels, our results overall demonstrate that induced defense organization of cotton subjected to varying damage treatments is in alignment with key assumptions of the ODT.

  7. Sea level change under IPCC-A2 scenario in Bohai, Yellow, and East China Seas

    Directory of Open Access Journals (Sweden)

    Chang-lin Chen

    2014-10-01

    Full Text Available Because of the environmental and socioeconomic impacts of anthropogenic sea level rise (SLR, it is very important to understand the processes leading to past and present SLRs towards more reliable future SLR projections. A regional ocean general circulation model (ROGCM, with a grid refinement in the Bohai, Yellow, and East China Seas (BYECSs, was set up to project SLR induced by the ocean dynamic change in the 21st century. The model does not consider the contributions from ice sheets and glacier melting. Data of all forcing terms required in the model came from the simulation of the Community Climate System Model version 3.0 (CCSM3 under the International Panel on Climate Change (IPCC-A2 scenario. Simulation results show that at the end of the 21st century, the sea level in the BYECSs will rise about 0.12 to 0.20 m. The SLR in the BYECSs during the 21st century is mainly caused by the ocean mass redistribution due to the ocean dynamic change of the Pacific Ocean, which means that water in the Pacific Ocean tends to move to the continental shelves of the BYECSs, although the local steric sea level change is another factor.

  8. Morphogenic and structural traits of Brachiaria brizantha cv. Marandu under different nitrogen levels and residues heights

    Directory of Open Access Journals (Sweden)

    Eleuza Clarete Junqueira de Sales

    2014-10-01

    Full Text Available The objective of this study was to evaluate the rate of leaf appearance, leaf elongation rate, number of green leaves, length of blade and stem of Brachiaria brizantha cv. Marandu under different nitrogen levels and two residue heights. A randomized block design was used in a 4 x 2 factorial scheme, four doses of nitrogen (100, 200, 300 and 400 kg N ha-1 year-1 and two residue heights (5 and 15 cm. There was significant interaction between residue height and nitrogen levels for leaf appearance rate (P> 0.05 of signal grass, which was influenced negatively and linearly (P 0.05 between the levels of nitrogen x residue height on the number of green leaves. The dosage that provided the highest stalk in the residue height of 5 cm was of 271.5 kg N ha -1. An increase of 0.0745 cm tiller -1 day-1 for 1 kg of N ha -1 applied to height of 15 cm of residue was observed. Nitrogen fertilization contributes positively to growth and development of rates of appearance and leaf extension. The management of pasture of Brachiaria brizantha cv. Marandu with 5 cm of residue and fertilization with 100 kg N ha -1 provided better answer morphogenic traits.

  9. Screening for cyanobacteria that evolve molecular hydrogen under dark and anaerobic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Yasuo, A.; Sugio, K.

    1986-01-01

    Cyanobacteria from culture collections were screened for those that evolve hydrogen gas endogenously under dark and anaerobic or microaerobic conditions. Twelve from 19 strains were demonstrated to evolve hydrogen, and the distribution of the activity was not related to nitrogen fixing capability or morphological grouping. The highest activity among those tested was 18.5 mul/16 h/mg dry cells by an axenic culture of Spirulina platensis M-185. 35 references.

  10. RNA sequencing of Populus x canadensis roots identifies key molecular mechanisms underlying physiological adaption to excess zinc.

    Directory of Open Access Journals (Sweden)

    Andrea Ariani

    Full Text Available Populus x canadensis clone I-214 exhibits a general indicator phenotype in response to excess Zn, and a higher metal uptake in roots than in shoots with a reduced translocation to aerial parts under hydroponic conditions. This physiological adaptation seems mainly regulated by roots, although the molecular mechanisms that underlie these processes are still poorly understood. Here, differential expression analysis using RNA-sequencing technology was used to identify the molecular mechanisms involved in the response to excess Zn in root. In order to maximize specificity of detection of differentially expressed (DE genes, we consider the intersection of genes identified by three distinct statistical approaches (61 up- and 19 down-regulated and validate them by RT-qPCR, yielding an agreement of 93% between the two experimental techniques. Gene Ontology (GO terms related to oxidation-reduction processes, transport and cellular iron ion homeostasis were enriched among DE genes, highlighting the importance of metal homeostasis in adaptation to excess Zn by P. x canadensis clone I-214. We identified the up-regulation of two Populus metal transporters (ZIP2 and NRAMP1 probably involved in metal uptake, and the down-regulation of a NAS4 gene involved in metal translocation. We identified also four Fe-homeostasis transcription factors (two bHLH38 genes, FIT and BTS that were differentially expressed, probably for reducing Zn-induced Fe-deficiency. In particular, we suggest that the down-regulation of FIT transcription factor could be a mechanism to cope with Zn-induced Fe-deficiency in Populus. These results provide insight into the molecular mechanisms involved in adaption to excess Zn in Populus spp., but could also constitute a starting point for the identification and characterization of molecular markers or biotechnological targets for possible improvement of phytoremediation performances of poplar trees.

  11. Design principles and optimal performance for molecular motors under realistic constraints.

    Science.gov (United States)

    Tu, Yuhai; Cao, Yuansheng

    2018-02-01

    The performance of a molecular motor, characterized by its power output and energy efficiency, is investigated in the motor design space spanned by the stepping rate function and the motor-track interaction potential. Analytic results and simulations show that a gating mechanism that restricts forward stepping in a narrow window in configuration space is needed for generating high power at physiologically relevant loads. By deriving general thermodynamics laws for nonequilibrium motors, we find that the maximum torque (force) at stall is less than its theoretical limit for any realistic motor-track interactions due to speed fluctuations. Our study reveals a tradeoff for the motor-track interaction: while a strong interaction generates a high power output for forward steps, it also leads to a higher probability of wasteful spontaneous back steps. Our analysis and simulations show that this tradeoff sets a fundamental limit to the maximum motor efficiency in the presence of spontaneous back steps, i.e., loose-coupling. Balancing this tradeoff leads to an optimal design of the motor-track interaction for achieving a maximum efficiency close to 1 for realistic motors that are not perfectly coupled with the energy source. Comparison with existing data and suggestions for future experiments are discussed.

  12. Molecular mechanisms underlying the close association between soil Burkholderia and fungi

    Science.gov (United States)

    Stopnisek, Nejc; Zühlke, Daniela; Carlier, Aurélien; Barberán, Albert; Fierer, Noah; Becher, Dörte; Riedel, Katharina; Eberl, Leo; Weisskopf, Laure

    2016-01-01

    Bacterial species belonging to the genus Burkholderia have been repeatedly reported to be associated with fungi but the extent and specificity of these associations in soils remain undetermined. To assess whether associations between Burkholderia and fungi are widespread in soils, we performed a co-occurrence analysis in an intercontinental soil sample collection. This revealed that Burkholderia significantly co-occurred with a wide range of fungi. To analyse the molecular basis of the interaction, we selected two model fungi frequently co-occurring with Burkholderia, Alternaria alternata and Fusarium solani, and analysed the proteome changes caused by cultivation with either fungus in the widespread soil inhabitant B. glathei, whose genome we sequenced. Co-cultivation with both fungi led to very similar changes in the B. glathei proteome. Our results indicate that B. glathei significantly benefits from the interaction, which is exemplified by a lower abundance of several starvation factors that were highly expressed in pure culture. However, co-cultivation also gave rise to stress factors, as indicated by the increased expression of multidrug efflux pumps and proteins involved in oxidative stress response. Our data suggest that the ability of Burkholderia to establish a close association with fungi mainly lies in the capacities to utilize fungal-secreted metabolites and to overcome fungal defense mechanisms. This work indicates that beneficial interactions with fungi might contribute to the survival strategy of Burkholderia species in environments with sub-optimal conditions, including acidic soils. PMID:25989372

  13. Molecular mechanisms underlying the entrance in secondary dormancy of Arabidopsis seeds.

    Science.gov (United States)

    Ibarra, Silvia E; Tognacca, Rocío S; Dave, Anuja; Graham, Ian A; Sánchez, Rodolfo A; Botto, Javier F

    2016-01-01

    As seasons change, dormant seeds cycle through dormant states until the environmental conditions are favourable for seedling establishment. Dormancy cycle is widespread in the plant kingdom allowing the seeds to display primary and secondary dormancy. Several reports in the last decade have focused on understanding the molecular mechanisms of primary dormancy, but our knowledge regarding secondary dormancy is limited. Here, we studied secondary dormancy induced in Arabidopsis thaliana by incubating seeds at 25 °C in darkness for 4 d. By physiological, pharmacological, expression and genetics approaches, we demonstrate that (1) the entrance in secondary dormancy involves changes in the content and sensitivity to GA, but the content and sensitivity to ABA do not change, albeit ABA is required; (2) RGL2 promotes the entrance in secondary dormancy through ABI5 action; and (3) multivariate analysis with 18 geographical and environmental parameters of accession collection place suggests that temperature is an important variable influencing the induction of secondary dormancy in nature. © 2015 John Wiley & Sons Ltd.

  14. Molecular Mechanism Underlying the Entomotoxic Effect of Colocasia esculenta Tuber Agglutinin against Dysdercus cingulatus

    Directory of Open Access Journals (Sweden)

    Amit Roy #

    2015-10-01

    Full Text Available Colocasia esculenta tuber agglutinin (CEA, a mannose binding lectin, exhibits insecticidal efficacy against different hemipteran pests. Dysdercus cingulatus, red cotton bug (RCB, has also shown significant susceptibility to CEA intoxication. However, the molecular basis behind such entomotoxicity of CEA has not been addressed adequately. The present study elucidates the mechanism of insecticidal efficacy of CEA against RCB. Confocal and scanning electron microscopic analyses documented CEA binding to insect midgut tissue, resulting in an alteration of perimicrovillar membrane (PMM morphology. Internalization of CEA into insect haemolymph and ovary was documented by western blotting analyses. Ligand blot followed by mass spectrometric identification revealed the cognate binding partners of CEA as actin, ATPase and cytochrome P450. Deglycosylation and mannose inhibition assays indicated the interaction to probably be mannose mediated. Bioinformatic identification of putative glycosylation or mannosylation sites in the binding partners further supports the sugar mediated interaction. Correlating entomotoxicity of CEA with immune histological and binding assays to the insect gut contributes to a better understanding of the insecticidal potential of CEA and endorses its future biotechnological application.

  15. Molecular Mechanism Underlying the Entomotoxic Effect of Colocasia esculenta Tuber Agglutinin against Dysdercus cingulatus

    Science.gov (United States)

    Roy, Amit; Das, Sampa

    2015-01-01

    Colocasia esculenta tuber agglutinin (CEA), a mannose binding lectin, exhibits insecticidal efficacy against different hemipteran pests. Dysdercus cingulatus, red cotton bug (RCB), has also shown significant susceptibility to CEA intoxication. However, the molecular basis behind such entomotoxicity of CEA has not been addressed adequately. The present study elucidates the mechanism of insecticidal efficacy of CEA against RCB. Confocal and scanning electron microscopic analyses documented CEA binding to insect midgut tissue, resulting in an alteration of perimicrovillar membrane (PMM) morphology. Internalization of CEA into insect haemolymph and ovary was documented by western blotting analyses. Ligand blot followed by mass spectrometric identification revealed the cognate binding partners of CEA as actin, ATPase and cytochrome P450. Deglycosylation and mannose inhibition assays indicated the interaction to probably be mannose mediated. Bioinformatic identification of putative glycosylation or mannosylation sites in the binding partners further supports the sugar mediated interaction. Correlating entomotoxicity of CEA with immune histological and binding assays to the insect gut contributes to a better understanding of the insecticidal potential of CEA and endorses its future biotechnological application.

  16. A general theory for the lifetimes of giant molecular clouds under the influence of galactic dynamics

    Science.gov (United States)

    Jeffreson, Sarah M. R.; Kruijssen, J. M. Diederik

    2018-05-01

    We propose a simple analytic theory for environmentally dependent molecular cloud lifetimes, based on the large-scale (galactic) dynamics of the interstellar medium. Within this theory, the cloud lifetime is set by the time-scales for gravitational collapse, galactic shear, spiral arm interactions, epicyclic perturbations, and cloud-cloud collisions. It is dependent on five observable quantities, accessible through measurements of the galactic rotation curve, the gas and stellar surface densities, and the gas and stellar velocity dispersions of the host galaxy. We determine how the relative importance of each dynamical mechanism varies throughout the space of observable galactic properties, and conclude that gravitational collapse and galactic shear play the greatest role in setting the cloud lifetime for the considered range of galaxy properties, while cloud-cloud collisions exert a much lesser influence. All five environmental mechanisms are nevertheless required to obtain a complete picture of cloud evolution. We apply our theory to the galaxies M31, M51, M83, and the Milky Way, and find a strong dependence of the cloud lifetime upon galactocentric radius in each case, with a typical cloud lifetime between 10 and 50 Myr. Our theory is ideally suited for systematic observational tests with the Atacama Large Millimetre/submillimetre array.

  17. [Achieving pathogenesis understanding of ocular diseases by deciphering the underlying molecular pathways].

    Science.gov (United States)

    Huang, Qian

    2005-10-01

    The field of ophthalmology research has experienced a revolution since the 1970's, when molecular biology techniques were gradually and widely adopted. Many of the developments generated impact that went far beyond the field of ophthalmology. A classic case was the identification and characterization of the Retinoblastoma susceptibility gene (Rb), whose impact went far beyond the rare and obscure disease, as it provides key evidence for the concept of tumor suppressor gene and the "two hit" theory of tumor formation. The identification of scores of genes involved in retinitis pigmentosum (pigmentosa), on the other hand, show cases the complexity of multi-factorial diseases. Ophthalmology researchers in China have been quick in integrating these novel tools into their research. However, the field still lags behind in the effective use of these technologies to carry out in-depth inquiries into key disease mechanisms. The advent of "omics" technologies heralded a new era in biomedical research that allows for the global and rapid survey of genetic and biochemical profiles. Effective integration of these novel technologies into ophthalmology research will have far-reaching impact for the whole field.

  18. A general theory for the lifetimes of giant molecular clouds under the influence of galactic dynamics

    Science.gov (United States)

    Jeffreson, Sarah M. R.; Kruijssen, J. M. Diederik

    2018-03-01

    We propose a simple analytic theory for environmentally-dependent molecular cloud lifetimes, based on the large-scale (galactic) dynamics of the interstellar medium. Within this theory, the cloud lifetime is set by the time-scales for gravitational collapse, galactic shear, spiral arm interactions, epicyclic perturbations and cloud-cloud collisions. It is dependent on five observable quantities, accessible through measurements of the galactic rotation curve, the gas and stellar surface densities, and the gas and stellar velocity dispersions of the host galaxy. We determine how the relative importance of each dynamical mechanism varies throughout the space of observable galactic properties, and conclude that gravitational collapse and galactic shear play the greatest role in setting the cloud lifetime for the considered range of galaxy properties, while cloud-cloud collisions exert a much lesser influence. All five environmental mechanisms are nevertheless required to obtain a complete picture of cloud evolution. We apply our theory to the galaxies M31, M51, M83, and the Milky Way, and find a strong dependence of the cloud lifetime upon galactocentric radius in each case, with a typical cloud lifetime between 10 and 50 Myr. Our theory is ideally-suited for systematic observational tests with the Atacama Large Millimetre/submillimetre array.

  19. Undulations in a weakly interacting mechanically generated molecular braid under tension

    International Nuclear Information System (INIS)

    O’ Lee, D J

    2014-01-01

    We consider mechanically generated molecular braids composed of two molecules where long range interactions between them can be considered to be very weak. We describe a model that takes account of the thermal fluctuations of the braid, steric interactions between the molecules, and external mechanical forces. In this model, both sets of ends, of the two molecules, are considered to be separated by a fixed distance much larger than the radius of the braid. One set of ends is rotated to generate a braid of a certain number of pitches (or turns), while the other set remains fixed. This model may describe the situation in which the ends of each molecule are attached to a substrate and a magnetic bead; to the latter a pulling force and rotational torque can be applied. We discuss various aspects of our model. Most importantly, an expression for the free energy is given, from which equations, determining the various geometric parameters of the braid, can be obtained. By numerically solving these equations, we give predictions from the model for the external torque needed to produce a braid with a certain number of turns per bending persistence length, as well as the end to end extension of the two molecules for a given pulling force. Other geometric parameters, as well as the lateral force required to keep the ends of the two molecules apart, are also calculated. (paper)

  20. Molecular markers validation to drought resistance in wheat meal (Triticum aestivum L. under greenhouse conditions

    Directory of Open Access Journals (Sweden)

    Gabriel Julio

    2013-08-01

    Full Text Available With the aim to study the genetic resistance to drought and validate molecular markers co-localized with genes/QTLs for this factor, 16 varieties were evaluated as well as advanced lines of wheat meal (Triticum aestivum in two stages of crop development. Physiological parameters were considered: amount of chlorophyll (clo, wilting or severity degree (SEV and recovery (reco, morphological parameters: foliage dry matter (FDM and root dry matter (RDM, the integrated resistance mechanisms: water use efficiency (WUE, other parameters: number of grains (Ngrain and grain weight (Wgrain, biochemical parameters: Catalaza (CAT, Ascorbate Peroxidase (APX and Guaiacol Peroxidase (POX and three microsatellite markers (Xwmc603, Xwmc596, Xwmc9. Results showed significant differences for MSR and Ngrain. It was observed that Anzaldo, ERR2V.L-20, EARII2V.L-5, EARIZV.L-11, ERR2V.L-11 and EE2V.L-19 were the most resistant to drough water stress. There was a highly significant negative correlation between the MSR and Ngrain. All other variables showed low and non-significant correlations. In biochemical analyzes, the Anzaldo variety showed an increased enzymatic activity compared to controls in all cases (CAT-APX and POX, being the most resistant to water stress by drought. Finally, it was found that SSR markers (Xwmc596 and Xwmc9 are co-located with the gene / QTL of drought resistance and can be used for marker-assisted selection.

  1. Sustained molecular oxygen activation by solid iron doped silicon carbide under microwave irradiation: Mechanism and application to norfloxacin degradation.

    Science.gov (United States)

    Li, Hongbo; Chen, Jing; Hou, Huijie; Pan, Hong; Ma, Xiaoxue; Yang, Jiakuan; Wang, Linling; Crittenden, John C

    2017-12-01

    Sustained molecular oxygen activation by iron doped silicon carbide (Fe/SiC) was investigated under microwave (MW) irradiation. The catalytic performance of Fe/SiC for norfloxacin (NOR) degradation was also studied. Rapid mineralization in neutral solution was observed with a pseudo-first-order rate constant of 0.2239 min -1 under 540 W of MW irradiation for 20 min. Increasing Fe/SiC rod and MW power significantly enhanced the degradation and mineralization rate with higher yield of reactive oxygen species (ROS). Fe shell corrosion and subsequent Fe 0/II oxidation by molecular oxygen with MW activation was the key factor for NOR degradation through two-electron-transfer by Fe 0 under acidic conditions and single-electron-transfer by Fe II under neutral-alkaline solution. Removal rate of NOR was significantly affected by solution pH, showing higher degradation rates at both acidic and alkaline conditions. The highest removal efficiencies and rates at alkaline pH values were ascribed to the contribution of bound Fe II species on the Fe shell surface due to the hydroxylation of Fe/SiC. ·OH was the main oxidizing specie for NOR degradation, confirmed by density functional theory (DFT) calculations and radical scavenger tests. DFT calculations were conducted on the reaction/activation energies of the transition/final states of NOR/degradation products, combined with intermediate identification with high performance liquid chromatography coupled with a triple-quadruple mass spectrometer (HPLC-MS/MS), the piperazinyl ring was the most reactive site for ·OH attack, followed by further ring-opening and stepwise oxidation. In this study, Fe/SiC were proved to be an excellent catalyst for the treatment of fluoroquinolone antibiotics with MW activation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Molecular level biodegradation of phenol and its derivatives through dmp operon of Pseudomonas putida: A bio-molecular modeling and docking analysis.

    Science.gov (United States)

    Ray, Sujay; Banerjee, Arundhati

    2015-10-01

    Participation of Pseudomonas putida-derived methyl phenol (dmp) operon and DmpR protein in the biodegradation of phenol or other harmful, organic, toxic pollutants was investigated at a molecular level. Documentation documents that P. putida has DmpR protein which positively regulates dmp operon in the presence of inducers; like phenols. From the operon, phenol hydroxylase encoded by dmpN gene, participates in degrading phenols after dmp operon is expressed. For the purpose, the 3-D models of the four domains from DmpR protein and of the DNA sequences from the two Upstream Activation Sequences (UAS) present at the promoter region of the operon were demonstrated using discrete molecular modeling techniques. The best modeled structures satisfying their stereo-chemical properties were selected in each of the cases. To stabilize the individual structures, energy optimization was performed. In the presence of inducers, probable interactions among domains and then the two independent DNA structures with the fourth domain were perused by manifold molecular docking simulations. The complex structures were made to be stable by minimizing their overall energy. Responsible amino acid residues, nucleotide bases and binding patterns for the biodegradation, were examined. In the presence of the inducers, the biodegradation process is initiated by the interaction of phe50 from the first protein domain with the inducers. Only after the interaction of the last domain with the DNA sequences individually, the operon is expressed. This novel residue level study is paramount for initiating transcription in the operon; thereby leading to expression of phenol hydroxylase followed by phenol biodegradation. Copyright © 2015. Published by Elsevier B.V.

  3. Different routes, same pathways: Molecular mechanisms under silver ion and nanoparticle exposures in the soil sentinel Eisenia fetida

    International Nuclear Information System (INIS)

    Novo, Marta; Lahive, Elma; Díez-Ortiz, María; Matzke, Marianne; Morgan, Andrew J.; Spurgeon, David J.; Svendsen, Claus; Kille, Peter

    2015-01-01

    Use of nanotechnology products is increasing; with silver (Ag) nanoparticles particularly widely used. A key uncertainty surrounding the risk assessment of AgNPs is whether their effects are driven through the same mechanism of action that underlies the toxic effects of Ag ions. We present the first full transcriptome study of the effects of Ag ions and NPs in an ecotoxicological model soil invertebrate, the earthworm Eisenia fetida. Gene expression analyses indicated similar mechanisms for both silver forms with toxicity being exerted through pathways related to ribosome function, sugar and protein metabolism, molecular stress, disruption of energy production and histones. The main difference seen between Ag ions and NPs was associated with potential toxicokinetic effects related to cellular internalisation and communication, with pathways related to endocytosis and cilia being significantly enriched. These results point to a common final toxicodynamic response, but initial internalisation driven by different exposure routes and toxicokinetic mechanisms. - Highlights: • Molecular effects underlying Ag ions and NPs exposure were studied in Eisenia fetida. • Full transcriptomic study of a genetically characterised lineage. • NPs and ions presented a similar toxicodynamic response. • Internalisation of the two Ag forms by different toxicokinetic mechanisms. - Transcriptomic analyses after exposure of earthworms to silver NPs or ions showed a final common toxicodynamic response, but internalisation by different toxicokinetic mechanisms

  4. Early molecular events involved in Pinus pinaster Ait. somatic embryo development under reduced water availability: transcriptomic and proteomic analyses.

    Science.gov (United States)

    Morel, Alexandre; Teyssier, Caroline; Trontin, Jean-François; Eliášová, Kateřina; Pešek, Bedřich; Beaufour, Martine; Morabito, Domenico; Boizot, Nathalie; Le Metté, Claire; Belal-Bessai, Leila; Reymond, Isabelle; Harvengt, Luc; Cadene, Martine; Corbineau, Françoise; Vágner, Martin; Label, Philippe; Lelu-Walter, Marie-Anne

    2014-09-01

    Maritime pine somatic embryos (SEs) require a reduction in water availability (high gellan gum concentration in the maturation medium) to reach the cotyledonary stage. This key switch, reported specifically for pine species, is not yet well understood. To facilitate the use of somatic embryogenesis for mass propagation of conifers, we need a better understanding of embryo development. Comparison of both transcriptome (Illumina RNA sequencing) and proteome [two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis with mass spectrometry (MS) identification] of immature SEs, cultured on either high (9G) or low (4G) gellan gum concentration, was performed, together with analysis of water content, fresh and dry mass, endogenous abscisic acid (ABA; gas chromatography-MS), soluble sugars (high-pressure liquid chromatography), starch and confocal laser microscope observations. This multiscale, integrated analysis was used to unravel early molecular and physiological events involved in SE development. Under unfavorable conditions (4G), the glycolytic pathway was enhanced, possibly in relation to cell proliferation that may be antagonistic to SE development. Under favorable conditions (9G), SEs adapted to culture constraint by activating specific protective pathways, and ABA-mediated molecular and physiological responses promoting embryo development. Our results suggest that on 9G, germin-like protein and ubiquitin-protein ligase could be used as predictive markers of SE development, whereas protein phosphatase 2C could be a biomarker for culture adaptive responses. This is the first characterization of early molecular mechanisms involved in the development of pine SEs following an increase in gellan gum concentration in the maturation medium, and it is also the first report on somatic embryogenesis in conifers combining transcriptomic and proteomic datasets. © 2014 Scandinavian Plant Physiology Society.

  5. 50 CFR 216.16 - Prohibitions under the General Authorization for Level B harassment for scientific research.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Prohibitions under the General Authorization for Level B harassment for scientific research. 216.16 Section 216.16 Wildlife and Fisheries... Prohibitions under the General Authorization for Level B harassment for scientific research. It shall be...

  6. Carbon burial and storage in tropical salt marshes under the influence of sea level rise.

    Science.gov (United States)

    Ruiz-Fernández, A C; Carnero-Bravo, V; Sanchez-Cabeza, J A; Pérez-Bernal, L H; Amaya-Monterrosa, O A; Bojórquez-Sánchez, S; López-Mendoza, P G; Cardoso-Mohedano, J G; Dunbar, R B; Mucciarone, D A; Marmolejo-Rodríguez, A J

    2018-07-15

    Coastal vegetated habitats can be important sinks of organic carbon (C org ) and mitigate global warming by sequestering significant quantities of atmospheric CO 2 and storing sedimentary C org for long periods, although their C org burial and storage capacity may be affected by on-going sea level rise and human intervention. Geochemical data from published 210 Pb-dated sediment cores, collected from low-energy microtidal coastal wetlands in El Salvador (Jiquilisco Bay) and in Mexico (Salada Lagoon; Estero de Urias Lagoon; Sian Ka'an Biosphere Reserve) were revisited to assess temporal changes (within the last 100years) of C org concentrations, storage and burial rates in tropical salt marshes under the influence of sea level rise and contrasting anthropization degree. Grain size distribution was used to identify hydrodynamic changes, and δ 13 C to distinguish terrigenous sediments from those accumulated under the influence of marine transgression. Although the accretion rate ranges in all sediment records were comparable, C org concentrations (0.2-30%), stocks (30-465Mgha -1 , by extrapolation to 1m depth), and burial rates (3-378gm -2 year -1 ) varied widely within and among the study areas. However, in most sites sea level rise decreased C org concentrations and stocks in sediments, but increased C org burial rates. Lower C org concentrations were attributed to the input of reworked marine particles, which contribute with a lower amount of C org than terrigenous sediments; whereas higher C org burial rates were driven by higher mass accumulation rates, influenced by increased flooding and human interventions in the surroundings. C org accumulation and long-term preservation in tropical salt marshes can be as high as in mangrove or temperate salt marsh areas and, besides the reduction of C org stocks by ongoing sea level rise, the disturbance of the long-term buried C org inventories might cause high CO 2 releases, for which they must be protected as a part of

  7. Thermal analysis of two-level wind power converter under symmetrical grid fault

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede

    2013-01-01

    In this paper, the case of symmetrical grid fault when using the multi-MW wind turbine of partial-scale and full-scale two-level power converter are designed and investigated. Firstly, the different operation behaviors of the relevant power converters under the voltage dip will be described...... and analyzed. Simulations of different configurations regarding the loss distribution and the junction temperature of the power device are presented in respect to the various voltage dips. It is concluded that for both systems the power loss will change dramatically during the Low-Voltage Ride Through (LVRT......) condition as well as the junction temperature. For the full-scale wind turbine system, the most thermal stressed power device in the grid-side converter will appear at the grid voltage below 0.5 pu, and for the partial-scale wind turbine system, the most thermal stressed power device in the rotor...

  8. Variability in behavior and production among dairy cows fed under differing levels of competition.

    Science.gov (United States)

    Crossley, R E; Harlander-Matauschek, A; DeVries, T J

    2017-05-01

    The objective of this study was to investigate the effects of differing levels of competition for feed access on group-housed dairy cows, and on variations in behavior and productivity between individuals within each group. Eighteen lactating Holstein cows, averaging 77 ± 20 d in milk with a production of 46 ± 7 kg/d at the start of the trial, were divided into subgroups of 3 and fed a total mixed ration 3×/d. Groups were exposed to each of 3 competition levels: high (3 cows:1 feed bin), moderate (3 cows:2 feed bins), and low (3 cows:3 feed bins). Treatments were assigned in random order according to a modified Latin-square design, and each was applied for 10 d. Using an automated feed intake system, feeding behavior data (dry matter intake, feeding time, feeding rate, and meal patterns) were recorded for each cow on d 6 to 10 of each treatment period. Additional behavioral [sorting, rumination, competitive interactions (replacements), lying time] and production (milk yield and components) data were collected. Greater competition resulted in a reduction in feeding time (low = 202.6, moderate = 194.9, high = 183.6 min/d; SE = 8.84), and an increased rate of feed intake (low = 0.16, moderate = 0.18, high = 0.20 kg of dry matter/min; SE = 0.01), especially following fresh feed delivery and milking. Dry matter intake was similar across treatments (average of 29.1 kg/d). Meal length increased under high competition (low = 37.0, moderate = 36.6, high = 47.3 min/meal; SE = 5.05) due to greater non-feeding time within meals, which was approximately twice as long under high competition (low = 10.0, moderate = 10.8, high = 20.3 min/meal; SE = 3.24). Daily lying time (low = 10.2, moderate = 10.2, high = 9.5 h/d; SE = 0.51) and milk protein yield (low = 1.41, mod = 1.42, high = 1.36 kg/d; SE = 0.05) were reduced under high competition. Analysis of individual within-group variability, calculated as the daily standard deviation of each group, averaged across 5 recording days

  9. Radionuclide release from high level waste forms under repository conditions in clay or granite

    International Nuclear Information System (INIS)

    Godon, N.; Lanza, F.

    1990-01-01

    The behaviour of both fully active and simulated vitrified high level waste (HLW) has been studied under conditions that are likely to occur in future repositories in clay and granite. The simulated HLW was doped with Cs, Sr, Tc and the actinides and the leaching of these elements from the glass has been measured together with their concentrations in the water of the near-field and their distribution between the various components of the repository. The diffusion coefficients of several elements in Boom clay has also been measured. The results show that the concentrations of Tc and the actinides in the near-field of a repository will be very low and that the actinides will only diffuse very slowly away from the vicinity of the glass. 24 refs., 1 figs., 7 tabs

  10. Autophagy as a Molecular Target of Flavonoids Underlying their Protective Effects in Human Disease.

    Science.gov (United States)

    Prieto-Domínguez, Nestor; Garcia-Mediavilla, Maria V; Sanchez-Campos, Sonia; Mauriz, Jose L; Gonzalez-Gallego, Javier

    2018-01-01

    Autophagy is a cellular pathway with the ability to maintain cell homeostasis through the elimination of damaged or useless cellular components, and its deregulation may initiate or aggravate different human diseases. Flavonoids, a group of plant metabolites, are able to modulate different molecular and cellular processes including autophagy. To review the effects of flavonoids on autophagy pathway in both invasive and noninvasive human diseases, focusing on the global outcomes in their progression. Moreover, the efficacy of the combination of flavonoids with drugs or other natural nontoxic compounds was also reviewed. A literature search was performed to identify and analyze peer-reviewed publications containing in vitro and in vivo studies focused on autophagy deregulation in different proliferative and non-proliferative pathologies and the potential protective effects of flavonoids. Analyzed publications indicated that imbalance between cell death and survival induced by changes in autophagy play an important role in the pathophysiology of a number of human diseases. The use of different flavonoids as autophagy modulators, alone or in combination with other molecules, might be a worthy strategy in the treatment of cancer, neurodegenerative disorders, cardiovascular diseases, hepatic diseases, leishmaniasis, influenza, gastric ulcers produced by Helicobacter pylori infection, diabetes, asthma, age-related macular degeneration or osteoporosis. Flavonoids could potentially constitute important adjuvant agents of conventional therapies in the treatment of autophagy deregulation-related diseases. Moreover, combined therapy may help to diminish the doses of those conventional treatments, leading to reduced drug-derivative side effects and to improved patients' survival. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  11. Cellular and Molecular Defects Underlying Invasive Fungal Infections—Revelations from Endemic Mycoses

    Directory of Open Access Journals (Sweden)

    Pamela P. Lee

    2017-06-01

    Full Text Available The global burden of fungal diseases has been increasing, as a result of the expanding number of susceptible individuals including people living with human immunodeficiency virus (HIV, hematopoietic stem cell or organ transplant recipients, patients with malignancies or immunological conditions receiving immunosuppressive treatment, premature neonates, and the elderly. Opportunistic fungal pathogens such as Aspergillus, Candida, Cryptococcus, Rhizopus, and Pneumocystis jiroveci are distributed worldwide and constitute the majority of invasive fungal infections (IFIs. Dimorphic fungi such as Histoplasma capsulatum, Coccidioides spp., Paracoccidioides spp., Blastomyces dermatiditis, Sporothrix schenckii, Talaromyces (Penicillium marneffei, and Emmonsia spp. are geographically restricted to their respective habitats and cause endemic mycoses. Disseminated histoplasmosis, coccidioidomycosis, and T. marneffei infection are recognized as acquired immunodeficiency syndrome (AIDS-defining conditions, while the rest also cause high rate of morbidities and mortalities in patients with HIV infection and other immunocompromised conditions. In the past decade, a growing number of monogenic immunodeficiency disorders causing increased susceptibility to fungal infections have been discovered. In particular, defects of the IL-12/IFN-γ pathway and T-helper 17-mediated response are associated with increased susceptibility to endemic mycoses. In this review, we put together the various forms of endemic mycoses on the map and take a journey around the world to examine how cellular and molecular defects of the immune system predispose to invasive endemic fungal infections, including primary immunodeficiencies, individuals with autoantibodies against interferon-γ, and those receiving biologic response modifiers. Though rare, these conditions provide importance insights to host defense mechanisms against endemic fungi, which can only be appreciated in unique

  12. Cellular and Molecular Defects Underlying Invasive Fungal Infections—Revelations from Endemic Mycoses

    Science.gov (United States)

    Lee, Pamela P.; Lau, Yu-Lung

    2017-01-01

    The global burden of fungal diseases has been increasing, as a result of the expanding number of susceptible individuals including people living with human immunodeficiency virus (HIV), hematopoietic stem cell or organ transplant recipients, patients with malignancies or immunological conditions receiving immunosuppressive treatment, premature neonates, and the elderly. Opportunistic fungal pathogens such as Aspergillus, Candida, Cryptococcus, Rhizopus, and Pneumocystis jiroveci are distributed worldwide and constitute the majority of invasive fungal infections (IFIs). Dimorphic fungi such as Histoplasma capsulatum, Coccidioides spp., Paracoccidioides spp., Blastomyces dermatiditis, Sporothrix schenckii, Talaromyces (Penicillium) marneffei, and Emmonsia spp. are geographically restricted to their respective habitats and cause endemic mycoses. Disseminated histoplasmosis, coccidioidomycosis, and T. marneffei infection are recognized as acquired immunodeficiency syndrome (AIDS)-defining conditions, while the rest also cause high rate of morbidities and mortalities in patients with HIV infection and other immunocompromised conditions. In the past decade, a growing number of monogenic immunodeficiency disorders causing increased susceptibility to fungal infections have been discovered. In particular, defects of the IL-12/IFN-γ pathway and T-helper 17-mediated response are associated with increased susceptibility to endemic mycoses. In this review, we put together the various forms of endemic mycoses on the map and take a journey around the world to examine how cellular and molecular defects of the immune system predispose to invasive endemic fungal infections, including primary immunodeficiencies, individuals with autoantibodies against interferon-γ, and those receiving biologic response modifiers. Though rare, these conditions provide importance insights to host defense mechanisms against endemic fungi, which can only be appreciated in unique climatic and

  13. Comparative Analysis of Latex Transcriptome Reveals Putative Molecular Mechanisms Underlying Super Productivity of Hevea brasiliensis

    Science.gov (United States)

    Li, Heping; Fan, Yujie; Yang, Jianghua; Qi, Jiyan; Li, Huibo

    2013-01-01

    Increasing demand for natural rubber prompts studies into the mechanisms governing the productivity of rubber tree (Heveabrasiliensis). It is very interesting to notice that a rubber tree of clone PR107 in Yunnan, China is reported to yield more than 20 times higher than the average rubber tree. This super-high-yielding (SHY) rubber tree (designated as SY107), produced 4.12 kg of latex (cytoplasm of rubber producing laticifers, containing about 30% of rubber) per tapping, more than 7-fold higher than that of the control. This rubber tree is therefore a good material to study how the rubber production is regulated at a molecular aspect. A comprehensive cDNA-AFLP transcript profiling was performed on the latex of SY107 and its average counterparts by using the 384 selective primer pairs for two restriction enzyme combinations (ApoI/MseI and TaqI/MseI). A total of 746 differentially expressed (DE) transcript-derived fragments (TDFs) were identified, of which the expression patterns of 453 TDFs were further confirmed by RT-PCR. These RT-PCR confirmed TDFs represented 352 non-redundant genes, of which 215 had known or partially known functions and were grouped into 10 functional categories. The top three largest categories were transcription and protein synthesis (representing 24.7% of the total genes), defense and stress (15.3%), and primary and secondary metabolism (14.0%). Detailed analysis of the DE-genes suggests notable characteristics of SHY phenotype in improved sucrose loading capability, rubber biosynthesis-preferred sugar utilization, enhanced general metabolism and timely stress alleviation. However, the SHY phenotype has little correlation with rubber-biosynthesis pathway genes. PMID:24066172

  14. Molecular mechanisms underlying antiproliferative and differentiating responses of hepatocarcinoma cells to subthermal electric stimulation.

    Directory of Open Access Journals (Sweden)

    María Luisa Hernández-Bule

    Full Text Available Capacitive Resistive Electric Transfer (CRET therapy applies currents of 0.4-0.6 MHz to treatment of inflammatory and musculoskeletal injuries. Previous studies have shown that intermittent exposure to CRET currents at subthermal doses exert cytotoxic or antiproliferative effects in human neuroblastoma or hepatocarcinoma cells, respectively. It has been proposed that such effects would be mediated by cell cycle arrest and by changes in the expression of cyclins and cyclin-dependent kinase inhibitors. The present work focuses on the study of the molecular mechanisms involved in CRET-induced cytostasis and investigates the possibility that the cellular response to the treatment extends to other phenomena, including induction of apoptosis and/or of changes in the differentiation stage of hepatocarcinoma cells. The obtained results show that the reported antiproliferative action of intermittent stimulation (5 m On/4 h Off with 0.57 MHz, sine wave signal at a current density of 50 µA/mm(2, could be mediated by significant increase of the apoptotic rate as well as significant changes in the expression of proteins p53 and Bcl-2. The results also revealed a significantly decreased expression of alpha-fetoprotein in the treated samples, which, together with an increased concentration of albumin released into the medium by the stimulated cells, can be interpreted as evidence of a transient cytodifferentiating response elicited by the current. The fact that this type of electrical stimulation is capable of promoting both, differentiation and cell cycle arrest in human cancer cells, is of potential interest for a possible extension of the applications of CRET therapy towards the field of oncology.

  15. Solutions for ecosystem-level protection of ocean systems under climate change.

    Science.gov (United States)

    Queirós, Ana M; Huebert, Klaus B; Keyl, Friedemann; Fernandes, Jose A; Stolte, Willem; Maar, Marie; Kay, Susan; Jones, Miranda C; Hamon, Katell G; Hendriksen, Gerrit; Vermard, Youen; Marchal, Paul; Teal, Lorna R; Somerfield, Paul J; Austen, Melanie C; Barange, Manuel; Sell, Anne F; Allen, Icarus; Peck, Myron A

    2016-12-01

    The Paris Conference of Parties (COP21) agreement renewed momentum for action against climate change, creating the space for solutions for conservation of the ocean addressing two of its largest threats: climate change and ocean acidification (CCOA). Recent arguments that ocean policies disregard a mature conservation research field and that protected areas cannot address climate change may be oversimplistic at this time when dynamic solutions for the management of changing oceans are needed. We propose a novel approach, based on spatial meta-analysis of climate impact models, to improve the positioning of marine protected areas to limit CCOA impacts. We do this by estimating the vulnerability of ocean ecosystems to CCOA in a spatially explicit manner and then co-mapping human activities such as the placement of renewable energy developments and the distribution of marine protected areas. We test this approach in the NE Atlantic considering also how CCOA impacts the base of the food web which supports protected species, an aspect often neglected in conservation studies. We found that, in this case, current regional conservation plans protect areas with low ecosystem-level vulnerability to CCOA, but disregard how species may redistribute to new, suitable and productive habitats. Under current plans, these areas remain open to commercial extraction and other uses. Here, and worldwide, ocean conservation strategies under CCOA must recognize the long-term importance of these habitat refuges, and studies such as this one are needed to identify them. Protecting these areas creates adaptive, climate-ready and ecosystem-level policy options for conservation, suitable for changing oceans. © 2016 John Wiley & Sons Ltd.

  16. Multiscale Modeling of Molecular Sieving in LTA-type Zeolites : From the Quantum Level to the Macroscopic

    OpenAIRE

    Mace, Amber

    2015-01-01

    LTA-type zeolites with narrow window apertures coinciding with the approximate size of small gaseous molecules such as CO2 and N2 are interesting candidates for adsorbents with swing adsorption technologies due to their molecular sieving capabilities and otherwise attractive properties. These sieving capabilities are dependent on the energy barriers of diffusion between the zeolite pores, which can be fine-tuned by altering the framework composition. An ab initio level of theory is necessary ...

  17. Impact-Based Electromagnetic Energy Harvester with High Output Voltage under Low-Level Excitations

    Directory of Open Access Journals (Sweden)

    Qian Luo

    2017-11-01

    Full Text Available To expand the applications of vibrational energy harvesters (VEHs as power sources of wireless sensor nodes, it is of significance to improve the scavenging efficiency for the broadband, low-frequency, and low-level vibrational energy. The output voltages of electromagnetic vibrational energy harvesters (EMVEHs are usually low, which complicates the power management circuit by an indispensable voltage boosting element. To this end, an impact-based non-resonant EMVEH mainly composed of an outer frame and an inner frame on rollers is proposed. Numerical simulations based on a mathematical model of the harvester are conducted to analyze the effects of structural parameters on the output performance. Under base excitation of 0.1 and 0.3 (where g is the gravitational acceleration, 1 g = 9.8 m · s − 2 , the experimental maximum root mean square voltages of a harvester prototype across a resistor of 11 kΩ are as high as 7.6 and 16.5 V at 6.0 and 8.5 Hz, respectively, with the maximum output powers of 5.3 and 24.8 mW, or the power densities of 54.6 and 256 μW cm−3. By using a management circuit without a voltage boosting element, a wireless sensor node driven by the prototype can measure and transmit the temperature and humidity every 20 s under base excitation of 0.1 g at 5.4 Hz.

  18. Antiherbivore defense mutualism under elevated carbon dioxide level: A fungal endophyte and grass

    Energy Technology Data Exchange (ETDEWEB)

    Marks, S. [Winthrop Univ., Rock Hill, SC (United States); Lincoln, D.E. [Univ. of South Carolina, Columbia, SC (United States)

    1996-06-01

    Previous studies have shown that insects commonly consume more when fed leaf tissue grown under CO{sub 2} enrichment, but with few negative effects on growth. However, lepidoteran larvae fed tissue infected with Balansiae fungal endophytes (which product toxic alkaloids) typically eat less but also suffer negative effects on growth and survival. This study was carried out to understand how these 2 factors may interact to affect larval consumption and growth in fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae). Infected and uninfected ramets of a single genotype of tall fescue, Festuca arundinacea Schreb., were grown under CO{sub 2} concentrations, but was not influenced by infection. As expected, larvae had significantly reduced efficiency of conversion of ingested food. These 2 factors also interacted so that the lowest efficiency of conversion of ingested food was seen when both infection and an enriched atmospheric CO{sub 2} environment were present. As global atmospheric CO{sub 2} levels continue to increase, it appears that fungal endophytes will continue to be important in turfgrasses as protection against insect herbivores and may lead to increased fitness for infected plant genotypes. 47 refs., 4 figs., 1 tab.

  19. Molecular level structural analysis of natural organic matter and of humic substances by NMR spectroscopy

    OpenAIRE

    Dr. Hertkorn, Norbert

    2007-01-01

    Natural organic matter (NOM) represents an ubiquitous, very complex mixture of organic and (a few) inorganic constituents and occurs in terrestrial, limnic and marine ecosystems. NOM plays immensely important roles in the natural world, and it is a key refractory constituent of the global carbon and other element cycles. The characterization and structural analysis of NOM, which features a substantial extent of both polydispersity and molecular heterogeneity, is most demanding with respect of...

  20. MILLIMETER-SCALE GENETIC GRADIENTS AND COMMUNITY-LEVEL MOLECULAR CONVERGENCE IN A HYPERSALINE MICROBIAL MAT

    Energy Technology Data Exchange (ETDEWEB)

    Fenner, Marsha W; Kunin, Victor; Raes, Jeroen; Harris, J. Kirk; Spear, John R.; Walker, Jeffrey J.; Ivanova, Natalia; Mering, Christian von; Bebout, Brad M.; Pace, Norman R.; Bork, Peer; Hugenholtz, Philip

    2008-04-30

    To investigate the extent of genetic stratification in structured microbial communities, we compared the metagenomes of 10 successive layers of a phylogenetically complex hypersaline mat from Guerrero Negro, Mexico. We found pronounced millimeter-scale genetic gradients that are consistent with the physicochemical profile of the mat. Despite these gradients, all layers displayed near identical and acid-shifted isoelectric point profiles due to a molecular convergence of amino acid usage indicating that hypersalinity enforces an overriding selective pressure on the mat community.

  1. Molecular dynamics simulation of Cu/Au thin films under temperature gradient

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qibin, E-mail: qibinli@cqu.edu.cn [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030 (China); Chongqing Key Laboratory of Heterogeneous Material Mechanics, Chongqing University, Chongqing 400030 (China); Peng, Xianghe [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030 (China); Peng, Tiefeng, E-mail: pengtiefeng@cqu.edu.cn [State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030 (China); Tang, Qizhong [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); Zhang, Xiaomin [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); Chongqing Key Laboratory of Heterogeneous Material Mechanics, Chongqing University, Chongqing 400030 (China); Huang, Cheng [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China)

    2015-12-01

    Graphical abstract: Heat transportation in the thin films. - Highlights: • The coherent lattice interface is found at thin films after annealing. • The vacancies are observed clearly in the deposit thin films. • The defect and component will influence the energy transportation in the coatings. • The vacancies and lattice mismatch can enlarge the mobility of atoms. • The phonon transportation in thin films has no apparent rule. - Abstract: Three modulation period thin films, 1.8 nm Cu/3.6 nm Au, 2.7 nm Cu/2.7 nm Au and 3.6 nm Cu/1.8 nm Au, are obtained from deposition method and ideal modeling based on lattice constant, to examine their structures and thermophysical characteristics under temperature gradient. The coherent lattice interface is found both at deposit and ideal thin films after annealing. Also, the vacancies are observed clearly in the deposit thin films. The defect and component of thin films will influence the energy transportation in the coatings. The vacancies and lattice mismatch can enlarge the mobility of atoms and result in the failure of coating under the thermal stress. The power spectrum of atoms’ movement has no apparent rule for phonon transportation in thin films. The results are helpful to reveal the micro-mechanism and provide reasonable basis for the failure of metallic coatings.

  2. Dogs, cats, and kin: a molecular species-level phylogeny of Carnivora.

    Science.gov (United States)

    Agnarsson, Ingi; Kuntner, Matjaz; May-Collado, Laura J

    2010-03-01

    problems with current classification. Our results also propose new, controversial hypotheses, such as the possible placement of the red panda (Ailuridae) sister to canids (Canidae). Our results confirm previous findings suggesting that the dog was domesticated from the Eurasian wolf (Canis lupus lupus) and are congruent with the Near East domestication of the cat. In sum, this study presents the most detailed species-level phylogeny of Carnivora to date and a much needed tool for comparative studies of carnivoran species. To demonstrate one such use, we perform a phylogenetic analysis of evolutionary distinctiveness (EDGE), which can be used to help establish conservation priorities. According with those criteria, and under one of the many possible sets of parameters, the highest priority Carnivora species for conservation of evolutionary diversity include: monk seals, giant and red panda, giant otter, otter civet, Owston's palm civet, sea otter, Liberian mongoose, spectacled bear, walrus, binturong, and the fossa. Published by Elsevier Inc.

  3. GLYCOSIDASES IN HUMAN BLOOD PLASMA AND URINE. MOLECULAR FORMS AND ACTIVITY LEVELS

    Directory of Open Access Journals (Sweden)

    Reza Seyed Yazdani

    1982-05-01

    Full Text Available The isoe lect r i c f ocusing p a t terns and pH activity cur ves of f i ve glycosidas e e nzymes i n blood plasma and ur i ne were s t ud i e d . This s tudy demons trated the presence o f a sing le molecular f onn in a -glucosidase and of two mole cul a r fonns of the enzymes H-a ce t yl-B-D-gluco sarni nidase, Na c e t y l -•p-D-g a l a c t o s amin i ua s e and S-glucuronidase i n both plasma and urine . B-Galactosidase existed as a s i ng le major molecular f orm i n p l asma and a t l e a st t wo molecular forms in urine. Spe cific activity of each~ le n zyme was determined in p lasma and urine The validity o f taking the ratio between two e n zvrne activities as an index for scr een .l.ng of fr ene t ic di s e a s e is discussed.

  4. Dialkylthio Substitution: An Effective Method to Modulate the Molecular Energy Levels of 2D-BDT Photovoltaic Polymers.

    Science.gov (United States)

    Yao, Huifeng; Zhang, Hao; Ye, Long; Zhao, Wenchao; Zhang, Shaoqing; Hou, Jianhui

    2016-02-17

    Dialkylthio-substituted thienyl-benzodithiophene (BDT-DST) was designed and synthesized as a building block to modulate the molecular levels of the conjugated polymers, and three copolymers named PDST-BDD, PDST-TT and PDST-DPP were prepared and applied in polymer solar cells (PSCs). Theoretical calculations and electrochemical cyclic voltammetry (CV) measurement suggested that the dialkylthio group could decrease the molecular energy levels of the resulting polymers distinctly. The open-circuit voltage (VOC) of PSC devices based on PDST-BDD, PDST-TT, and PDST-DPP are as high as 1.0, 0.98, and 0.88 V, respectively, which are ∼0.15 V higher than those of the corresponding alky-substituted analogues. Moreover, the influence of the dialkylthio group on the absorption spectra, crystalline properties, hole mobilities, and blend morphologies of the polymers was also investigated. The results indicate that the dialkythio substitution is an effective method to modulate the molecular energy levels and that the BDT-DST unit has potential for constructing high-efficiency photovoltaic polymers.

  5. Field Performance of Five Soybean Mutants Under Drought Stress Conditions and Molecular Analysis Using SSR Markers

    Directory of Open Access Journals (Sweden)

    Y Yuliasti

    2017-08-01

    Full Text Available The objectives of this research wereto evaluate (1 the performance of soybean mutant lines under drought stress conditions, and(2 the genetic diversity and relationship among the mutant lines using SSR markers.The field evaluation was conducted during the dry season of 2011 and 2012 at the experimental Farm of Mataram University, West Nusa Tenggara, Indonesia. The field experiment was set up in a randomized block design. Ten mutant lines and two control varieties were evaluated in four replications. Genetic distance among evaluated lines were determined based on allelic diversity analysis using 40 simple sequence repeat (SSR loci. Under drought stress conditions, two mutant lines, Kdl3 and Kdl8,showed a better performance compared to the other ones. The high yielding mutant lines were Kdl3and Kdl8, which yielded 1.75 t ha-1and 1.69 t ha-1, respectively, compared to the parent and national control, Panderman 1.43 t ha-1 and Muria 1.32 t ha-1. These mutant linesrequired 30.75 to 32days to flower and 79.75 to 83.75 day to harvest with relatively short plant height 28.25 and 23.35 cmrespectively. Those mutant characters were better than those of the other three mutants, the original parents, and the control soybean species. Since the evaluated soybean mutant lines yielded more under drought stress conditions than the standard varieties, they can be used and registered as drought-tolerant soybean mutants. Moreover, the evaluated soybean accessions showed a wide genetic distance. The accessions were clustered into two groups according to their genetic background, namelygroup I (the Panderman with three mutant lines and group II (the Muria with two mutant lines. Twenty-three out of 40 evaluated SSR loci, including AW31, BE806, CMAC7L, S080, S126, S57, S171, S224, S285, S294, S393, S294, S383, S511, S511, S520, S540, S547, S551, S571, S577, and S578, provided polymorphic alleles between the parents and their mutants and could be used to differentiate

  6. Thyroid hormone levels in patients with chronic renal failure under haemodialysis

    International Nuclear Information System (INIS)

    Khalid, Ahmed Shukralla M.

    1998-06-01

    This study was conducted with three main objectives, to study thyroid hormones (T 4 , T 3 ) and TSH levels in patients with CRF under haemodialysis and to compare them with normal subjects, to study best means of treatment and to compare these findings with results from other parts of the world. This study was done on 61 patients with renal failure in Khartoum dialysis and kidney transplant centre U of K, 45 males and 16 females with ages ranging from 17-75 years and 42 symptoms-free subjects 14 males and 23 females with age ranging from 16-60 years. The radioimmunoassay (RIA) technique was used for the determination of serum T 4 , T 3 and TSH. By using t-test found that the mean concentrations of T 4 , T 3 of normal subjects were much higher than those of the patients (p 0.05). These results also illustrated that 45.9% of patients with renal failure of low T 4 , and 91.8%, 90.26 of patients had T 3 and TSH hormone levels in the normal range, respectively. No significant difference was observed in the mean of thyroid hormones (T 4 , T 3 ) and thyroid-stimulating hormones between males and females (p>0.05). The T 3 and T '4 concentrations in patients at all age groups (year) was less than the age groups of the control group, and this decrease was statistically significant (p 0.05).(Author)

  7. Mineral composition of legumes forages cultivated under different levels of shade

    Directory of Open Access Journals (Sweden)

    João Carlos de Carvalho Almeida

    2015-02-01

    Full Text Available The objective of this study was to evaluate the composition of calcium, phosphorus and potassium, and the leaf: stem ratio of four tropical forage legumes: Calopogonium mucunoides (calopo, Pueraria phaseoloides (puero, Macrotyloma axillare (archer and Neonotonia wightii (perennial soybean, under different levels of artificial shade (0, 30, 50 and 70% in the summer and autumn seasons of 2006 and 2007, respectively. The experimental design was a randomized complete block in factorial 4x4 design with four replications. Was used SNK test at 5% probability to evaluate the effect of the legume species and regression analysis to test the effect of the level of shading. There was a trend of increase in the concentration of 3 independent minerals examined the season. In contrast, there was a reduction in the leaf: stem ratio and a slight increase in specific leaf area archer, perennial soybean and puero (R2 ? 40%, which suggests small effect of shading on the morphology of leaves of 3 forage legumes, which in turn have little effect concentrating minerals, besides these finding is confirmed the annual calopo behavior, which prevents their use as legume forage for the autumn season.

  8. Brachial blood flow under relative levels of blood flow restriction is decreased in a nonlinear fashion.

    Science.gov (United States)

    Mouser, J Grant; Ade, Carl J; Black, Christopher D; Bemben, Debra A; Bemben, Michael G

    2018-05-01

    Blood flow restriction (BFR), the application of external pressure to occlude venous return and restrict arterial inflow, has been shown to increase muscular size and strength when combined with low-load resistance exercise. BFR in the research setting uses a wide range of pressures, applying a pressure based upon an individual's systolic pressure or a percentage of occlusion pressure; not a directly determined reduction in blood flow. The relationship between relative pressure and blood flow has not been established. To measure blood flow in the arm under relative levels of BFR. Forty-five people (18-40 years old) participated. Arterial occlusion pressure in the right arm was measured using a 5-cm pneumatic cuff. Blood flow in the brachial artery was measured at rest and at pressures between 10% and 90% of occlusion using ultrasound. Blood flow decreased in a nonlinear, stepped fashion. Blood flow decreased at 10% of occlusion and remained constant until decreasing again at 40%, where it remained until 90% of occlusion. The decrease in brachial blood flow is not proportional to the applied relative pressure. The prescription of blood flow restriction should take into account the stimulus provided at each relative level of blood flow. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  9. Controller Strategies for Automation Tool Use under Varying Levels of Trajectory Prediction Uncertainty

    Science.gov (United States)

    Morey, Susan; Prevot, Thomas; Mercer, Joey; Martin, Lynne; Bienert, Nancy; Cabrall, Christopher; Hunt, Sarah; Homola, Jeffrey; Kraut, Joshua

    2013-01-01

    A human-in-the-loop simulation was conducted to examine the effects of varying levels of trajectory prediction uncertainty on air traffic controller workload and performance, as well as how strategies and the use of decision support tools change in response. This paper focuses on the strategies employed by two controllers from separate teams who worked in parallel but independently under identical conditions (airspace, arrival traffic, tools) with the goal of ensuring schedule conformance and safe separation for a dense arrival flow in en route airspace. Despite differences in strategy and methods, both controllers achieved high levels of schedule conformance and safe separation. Overall, results show that trajectory uncertainties introduced by wind and aircraft performance prediction errors do not affect the controllers' ability to manage traffic. Controller strategies were fairly robust to changes in error, though strategies were affected by the amount of delay to absorb (scheduled time of arrival minus estimated time of arrival). Using the results and observations, this paper proposes an ability to dynamically customize the display of information including delay time based on observed error to better accommodate different strategies and objectives.

  10. Penguin chicks benefit from elevated yolk androgen levels under sibling competition.

    Directory of Open Access Journals (Sweden)

    Maud Poisbleau

    Full Text Available Crested penguins (genus Eudyptes have a peculiar hatching pattern, with the first-laid egg (A-egg hatching after the second-laid egg (B-egg and chicks from A-eggs typically having a much lower survival probability. Maternal yolk androgens have been suggested to contribute to the competitive superiority of the B-chick in southern rockhopper penguins Eudyptes chrysocome, given their important role in mediating sibling competition in other species. We therefore increased the yolk androgen levels in freshly-laid eggs and examined the consequences for sibling competition--via effects on embryonic developmental times, chick growth and early survival. We placed one androgen-treated egg and one control egg into each foster nest, matching them for mass, laying date and laying order. The androgen treatment did not significantly affect embryonic developmental times or chick measurements at hatching. However, elevated yolk androgen levels benefitted chick growth in interaction with the number of siblings in a brood. Chicks from androgen-treated eggs had faster growth in the presence of a sibling than chicks from control eggs. Under these circumstances they also had a higher survival probability. Thus maternal androgens appear to reinforce the observed hatching pattern, facilitating brood reduction. This contrasts to most previous studies in other species where yolk androgens have been shown to compensate for the negative consequences of delayed hatching within the brood hierarchy.

  11. Low environmentally relevant levels of bioactive xenobiotics and associated degradation products cause cryptic perturbations of metabolism and molecular stress responses in Arabidopsis thaliana.

    Science.gov (United States)

    Serra, Anne-Antonella; Nuttens, Andréïna; Larvor, Vanessa; Renault, David; Couée, Ivan; Sulmon, Cécile; Gouesbet, Gwenola

    2013-07-01

    Anthropic changes and chemical pollution confront wild plant communities with xenobiotic combinations of bioactive molecules, degradation products, and adjuvants that constitute chemical challenges potentially affecting plant growth and fitness. Such complex challenges involving residual contamination and mixtures of pollutants are difficult to assess. The model plant Arabidopsis thaliana was confronted by combinations consisting of the herbicide glyphosate, the fungicide tebuconazole, the glyphosate degradation product aminomethylphosphonic acid (AMPA), and the atrazine degradation product hydroxyatrazine, which had been detected and quantified in soils of field margins in an agriculturally intensive region. Integrative analysis of physiological, metabolic, and gene expression responses was carried out in dose-response experiments and in comparative experiments of varying pesticide combinations. Field margin contamination levels had significant effects on plant growth and metabolism despite low levels of individual components and the presence of pesticide degradation products. Biochemical and molecular analysis demonstrated that these less toxic degradation products, AMPA and hydroxyatrazine, by themselves elicited significant plant responses, thus indicating underlying mechanisms of perception and transduction into metabolic and gene expression changes. These mechanisms may explain observed interactions, whether positive or negative, between the effects of pesticide products (AMPA and hydroxyatrazine) and the effects of bioactive xenobiotics (glyphosate and tebuconazole). Finally, the metabolic and molecular perturbations induced by low levels of xenobiotics and associated degradation products were shown to affect processes (carbon balance, hormone balance, antioxidant defence, and detoxification) that are likely to determine environmental stress sensitivity.

  12. Review process for low-level radioactive waste disposal license application under Low-Level Radioactive Waste Policy Amendments Act

    International Nuclear Information System (INIS)

    Pittiglio, C.L. Jr.

    1987-08-01

    This document estimates the level of effort and expertise that is needed to review a license application within the required time. It is intended to be used by the NRC staff as well as States and interested parties to provide a better understanding of what the NRC envisions will be involved in licensing a low-level radioactive waste disposal facility. 5 refs., 3 figs., 1 tab

  13. Functional Proteomics Defines the Molecular Switch Underlying FGF Receptor Trafficking and Cellular Outputs

    DEFF Research Database (Denmark)

    Francavilla, Chiara; Rigbolt, Kristoffer T.G.; Emdal, Kristina B

    2013-01-01

    The stimulation of fibroblast growth factor receptors (FGFRs) with distinct FGF ligands generates specific cellular responses. However, the mechanisms underlying this paradigm have remained elusive. Here, we show that FGF-7 stimulation leads to FGFR2b degradation and, ultimately, cell proliferation......, whereas FGF-10 promotes receptor recycling and cell migration. By combining mass-spectrometry-based quantitative proteomics with fluorescence microscopy and biochemical methods, we find that FGF-10 specifically induces the rapid phosphorylation of tyrosine (Y) 734 on FGFR2b, which leads to PI3K and SH3BP4...... recruitment. This complex is crucial for FGFR2b recycling and responses, given that FGF-10 stimulation of either FGFR2b_Y734F mutant- or SH3BP4-depleted cells switches the receptor endocytic route to degradation, resulting in decreased breast cancer cell migration and the inhibition of epithelial branching...

  14. The molecular mechanism underlying Roberts syndrome involves loss of ESCO2 acetyltransferase activity

    DEFF Research Database (Denmark)

    Gordillo, M.; Vega, H.; Trainer, A.H.

    2008-01-01

    Roberts syndrome/SC phocomelia (RBS) is an autosomal recessive disorder with growth retardation, craniofacial abnormalities and limb reduction. Cellular alterations in RBS include lack of cohesion at the heterochromatic regions around centromeres and the long arm of the Y chromosome, reduced growth...... and nonsense mutations associated with decreased levels of mRNA and absence of protein. We found decreased proliferation capacity in RBS cell lines associated with cell death, but not with increased cell cycle duration, which could be a factor in the development of phocomelia and cleft palate in RBS...

  15. Neural correlates of erotic stimulation under different levels of female sexual hormones.

    Directory of Open Access Journals (Sweden)

    Birgit Abler

    Full Text Available Previous studies have demonstrated variable influences of sexual hormonal states on female brain activation and the necessity to control for these in neuroimaging studies. However, systematic investigations of these influences, particularly those of hormonal contraceptives as compared to the physiological menstrual cycle are scarce. In the present study, we investigated the hormonal modulation of neural correlates of erotic processing in a group of females under hormonal contraceptives (C group; N = 12, and a different group of females (nC group; N = 12 not taking contraceptives during their mid-follicular and mid-luteal phases of the cycle. We used functional magnetic resonance imaging to measure hemodynamic responses as an estimate of brain activation during three different experimental conditions of visual erotic stimulation: dynamic videos, static erotic pictures, and expectation of erotic pictures. Plasma estrogen and progesterone levels were assessed in all subjects. No strong hormonally modulating effect was detected upon more direct and explicit stimulation (viewing of videos or pictures with significant activations in cortical and subcortical brain regions previously linked to erotic stimulation consistent across hormonal levels and stimulation type. Upon less direct and less explicit stimulation (expectation, activation patterns varied between the different hormonal conditions with various, predominantly frontal brain regions showing significant within- or between-group differences. Activation in the precentral gyrus during the follicular phase in the nC group was found elevated compared to the C group and positively correlated with estrogen levels. From the results we conclude that effects of hormonal influences on brain activation during erotic stimulation are weak if stimulation is direct and explicit but that female sexual hormones may modulate more subtle aspects of sexual arousal and behaviour as involved in sexual

  16. First results on enzymatic activities in two salt marsh soils under different hydromorphic level and vegetation

    Directory of Open Access Journals (Sweden)

    Carmen Trasar-Cepeda

    2015-12-01

    Full Text Available Salt-marsh soils are soils characterized by non-permanent hydric saturation that, depending on factors like duration of submersion periods, are dominated by different salt-tolerant plant species. The composition of microbial communities is an essential component in trophic dynamics and biogeochemical processes in salt marshes, and determines the level of enzymatic activities, which catalyze the conversion of complex molecules into simpler ones. Despite of this, the enzymatic activities in marsh-soils has not yet been investigated. The aim of this study was to analyze the enzymatic activities in two soil profiles of marsh-soils under different water saturation level and dominated by different plant species [Juncus maritimus Lam and Spartina maritima (Curtis Fernald (Sp]. In both soils, the enzymatic activities were much lower than the levels typically found in terrestrial ecosystems. The enzymatic activities were measured both in air-dried and in re-moistened and incubated soil samples. In air-dried samples, the enzymatic activities were higher in Juncus than in Spartina soil and tended to decrease with depth, being sharper the decrease in Juncus than in Spartina soil. Re-moistened and pre-incubated soils showed a general increase in all the enzymatic activities and throughout the whole soil profile, especially in Spartina soils. Hydrolase activities showed a strong and positive relationship with organic matter content both in air-dried and in re-moistened soil samples, higher in these latter. In general, oxidoreductase activities only showed this relationship in re-moistened soil samples. More studies, preferably using freshly collected soil samples, are needed to understand the relationship between enzymatic activities and these environmental conditions.

  17. Dithiothreitol activity by particulate oxidizers of SOA produced from photooxidation of hydrocarbons under varied NOx levels

    Directory of Open Access Journals (Sweden)

    H. Jiang

    2017-08-01

    Full Text Available When hydrocarbons (HCs are atmospherically oxidized, they form particulate oxidizers, including quinones, organic hydroperoxides, and peroxyacyl nitrates (PANs. These particulate oxidizers can modify cellular materials (e.g., proteins and enzymes and adversely modulate cell functions. In this study, the contribution of particulate oxidizers in secondary organic aerosols (SOAs to the oxidative potential was investigated. SOAs were generated from the photooxidation of toluene, 1,3,5-trimethylbenzene, isoprene, and α-pinene under varied NOx levels. Oxidative potential was determined from the typical mass-normalized consumption rate (reaction time t =  30 min of dithiothreitol (DTTt, a surrogate for biological reducing agents. Under high-NOx conditions, the DTTt of toluene SOA was 2–5 times higher than that of the other types of SOA. Isoprene DTTt significantly decreased with increasing NOx (up to 69 % reduction by changing the HC ∕ NOx ratio from 30 to 5. The DTTt of 1,3,5-trimethylbenzene and α-pinene SOA was insensitive to NOx under the experimental conditions of this study. The significance of quinones to the oxidative potential of SOA was tested through the enhancement of DTT consumption in the presence of 2,4-dimethylimidazole, a co-catalyst for the redox cycling of quinones; however, no significant effect of 2,4-dimethylimidazole on modulation of DTT consumption was observed for all SOA, suggesting that a negligible amount of quinones was present in the SOA of this study. For toluene and isoprene, mass-normalized DTT consumption (DTTm was determined over an extended period of reaction time (t =  2 h to quantify their maximum capacity to consume DTT. The total quantities of PANs and organic hydroperoxides in toluene SOA and isoprene SOA were also measured using the Griess assay and the 4-nitrophenylboronic acid assay, respectively. Under the NOx conditions (HC ∕ NOx ratio: 5–36 ppbC ppb−1 applied in

  18. Dithiothreitol activity by particulate oxidizers of SOA produced from photooxidation of hydrocarbons under varied NOx levels

    Science.gov (United States)

    Jiang, Huanhuan; Jang, Myoseon; Yu, Zechen

    2017-08-01

    When hydrocarbons (HCs) are atmospherically oxidized, they form particulate oxidizers, including quinones, organic hydroperoxides, and peroxyacyl nitrates (PANs). These particulate oxidizers can modify cellular materials (e.g., proteins and enzymes) and adversely modulate cell functions. In this study, the contribution of particulate oxidizers in secondary organic aerosols (SOAs) to the oxidative potential was investigated. SOAs were generated from the photooxidation of toluene, 1,3,5-trimethylbenzene, isoprene, and α-pinene under varied NOx levels. Oxidative potential was determined from the typical mass-normalized consumption rate (reaction time t = 30 min) of dithiothreitol (DTTt), a surrogate for biological reducing agents. Under high-NOx conditions, the DTTt of toluene SOA was 2-5 times higher than that of the other types of SOA. Isoprene DTTt significantly decreased with increasing NOx (up to 69 % reduction by changing the HC / NOx ratio from 30 to 5). The DTTt of 1,3,5-trimethylbenzene and α-pinene SOA was insensitive to NOx under the experimental conditions of this study. The significance of quinones to the oxidative potential of SOA was tested through the enhancement of DTT consumption in the presence of 2,4-dimethylimidazole, a co-catalyst for the redox cycling of quinones; however, no significant effect of 2,4-dimethylimidazole on modulation of DTT consumption was observed for all SOA, suggesting that a negligible amount of quinones was present in the SOA of this study. For toluene and isoprene, mass-normalized DTT consumption (DTTm) was determined over an extended period of reaction time (t = 2 h) to quantify their maximum capacity to consume DTT. The total quantities of PANs and organic hydroperoxides in toluene SOA and isoprene SOA were also measured using the Griess assay and the 4-nitrophenylboronic acid assay, respectively. Under the NOx conditions (HC / NOx ratio: 5-36 ppbC ppb-1) applied in this study, the amount of organic hydroperoxides was

  19. Submicron particulate organic matter in the urban atmosphere: a new method for real-time measurement, molecular-level characterization and source apportionment

    Science.gov (United States)

    Müller, Markus; Eichler, Philipp; D'Anna, Barbara; Tan, Wen; Wisthaler, Armin

    2017-04-01

    We used a novel chemical analytical method for measuring submicron particulate organic matter in the atmosphere of three European cities (Innsbruck, Lyon, Valencia). Proton-Transfer-Reaction Time-of-Flight Mass Spectrometry (PTR-ToF-MS) was used in combination with the "chemical analysis of aerosol online" (CHARON) inlet for detecting particulate organic compounds on-line (i.e. without filter pre-collection), in real-time (1-min time resolution), at ng m-3 concentrations, with molecular-level resolution (i.e. obtaining molecular weight and elemental composition information). The CHARON-PTR-ToF-MS system monitored molecular tracers associated with different particle sources including levoglucosan from biomass combustion, PAHs from vehicular traffic, nicotine from cigarette smoking, and monoterpene oxidation products secondarily formed from biogenic emissions. The tracer information was used for interpreting positive matrix factorization (PMF) data which allowed us to apportion the sources of submicron particulate organic matter in the different urban environments. This work was funded through the PIMMS ITN, which was supported by the European Commission's 7th Framework Programme under grant agreement number 287382.

  20. Loading Analysis of Modular Multi-level Converter for Offshore High-voltage DC Application under Various Grid Faults

    DEFF Research Database (Denmark)

    Liu, Hui; Ma, Ke; Loh, Poh Chiang

    2016-01-01

    challenges but may also result in overstressed components for the modular multi-level converter. However, the thermal loading of the modular multi-level converter under various grid faults has not yet been clarified. In this article, the power loss and thermal performance of the modular multi-level converter...... during grid voltage dips are studied. The impacts of two typical grid faults to the modular multi-level converter in terms of operating and loading conditions are analytically researched and simulated. It has been found that the operating and loading conditions of the modular multi-level converter under...

  1. Multi-study integration of brain cancer transcriptomes reveals organ-level molecular signatures.

    Directory of Open Access Journals (Sweden)

    Jaeyun Sung

    Full Text Available We utilized abundant transcriptomic data for the primary classes of brain cancers to study the feasibility of separating all of these diseases simultaneously based on molecular data alone. These signatures were based on a new method reported herein--Identification of Structured Signatures and Classifiers (ISSAC--that resulted in a brain cancer marker panel of 44 unique genes. Many of these genes have established relevance to the brain cancers examined herein, with others having known roles in cancer biology. Analyses on large-scale data from multiple sources must deal with significant challenges associated with heterogeneity between different published studies, for it was observed that the variation among individual studies often had a larger effect on the transcriptome than did phenotype differences, as is typical. For this reason, we restricted ourselves to studying only cases where we had at least two independent studies performed for each phenotype, and also reprocessed all the raw data from the studies using a unified pre-processing pipeline. We found that learning signatures across multiple datasets greatly enhanced reproducibility and accuracy in predictive performance on truly independent validation sets, even when keeping the size of the training set the same. This was most likely due to the meta-signature encompassing more of the heterogeneity across different sources and conditions, while amplifying signal from the repeated global characteristics of the phenotype. When molecular signatures of brain cancers were constructed from all currently available microarray data, 90% phenotype prediction accuracy, or the accuracy of identifying a particular brain cancer from the background of all phenotypes, was found. Looking forward, we discuss our approach in the context of the eventual development of organ-specific molecular signatures from peripheral fluids such as the blood.

  2. Paving the way to understand humoral autoantibody epilepsy on the molecular level

    Directory of Open Access Journals (Sweden)

    Guiscard eSeebohm

    2015-07-01

    Full Text Available Correct function of neuronal networks is enabled by a delicate interplay among neurons communicating with each other. One of the keys is the communication at chemical synapses where neurotransmitters like glutamate, GABA and glycine enable signal transfer over the synaptic cleft. Thereby, the neurotransmitters are released from the presynapse and bind as ligands to specific receptors at the postsynaptic side to allow for modulation of the postsynaptic membrane potentials. The postsynaptic electrical signal, which is highly modulated by voltage gated ion channels, spreads over the dendritic tree and is thus integrated to allow for generation of action potentials at the axon hillock. This concert of receptors and voltage gated ion channels depends on correct function of all its components. Misfunction of receptors and/or voltage-gated potassium channels (VGKC leads to diverse adverse effects in patients. Such malfunctions can be the result of inherited genetic alterations or pharmacological side effects by drugs. Recently, auto-antibodies targeting receptor or channel complexes like NMDAR, AMPAR, GABA-receptors, glycine-receptors, LGI1 or CASPR2 (previously termed VGKC-complex antibodies have been discovered. The presence of specific auto-antibodies against these targets associates with severe forms of antibody-mediated encephalitis. Understanding the molecular details of auto-antibody actions on receptor and VGKC complexes is highly desirable and may open the path to develop specific therapies to treat humoral autoimmune encephalitis. Here, we summarize the current knowledge and discuss technical approaches to fill the gap of knowledge. These techniques include electrophysiology, biochemical approaches for epitope mapping and in silico modeling to simulate molecular interactions between autoantibody and its molecular target.

  3. Molecular detection of Erwinia psidii in guava plants under greenhouse and field conditions

    Directory of Open Access Journals (Sweden)

    Claudênia Ferreira da Silva

    2016-09-01

    Full Text Available ABSTRACT: Erwinia psidii causes bacterial blight of guava ( Psidium guajava , an important disease of this crop in Brazil. The pathogen affects branches and twigs of guava trees, reducing yield significantly. Bacterial dissemination often occurs through contaminated but asymptomatic propagating plant material. The objectives of this research were to evaluate the use of BIO-PCR and conventional PCR to detect E. psidii in inoculated guava plants grown in a greenhouse and in symptomatic and asymptomatic trees from guava orchards. Erwinia psidii strain IBSBF 1576 was inoculated (107CFU mL-1 into young guava shoots and plant tissue was analysed at 0, 5, 10, and 15 days after inoculation. Symptoms were observed after 5 days and all inoculated shoots were PCR positive at all times, by both BIO-PCR and conventional PCR. Under natural infection conditions, 40 samples were tested by BIO-PCR from each of three guava orchards, 20 showing symptoms and 20 asymptomatic. PCR was positive for 58 out of 60 symptomatic samples (96.7% and for 6.7% of asymptomatic samples, showing that the method can be used to detect the pathogen at early stages of infection. This PCR method may be used as a diagnostic tool to assess bacterial survival, dissemination and disease outbreaks.

  4. Classical Galactosemia: Insight into Molecular Pathomechanisms by Differential Membrane Proteomics of Fibroblasts under Galactose Stress.

    Science.gov (United States)

    Staubach, Simon; Müller, Stefan; Pekmez, Murat; Hanisch, Franz-Georg

    2017-02-03

    Classical galactosemia, a hereditary metabolic disease caused by the deficiency of galactose-1-phosphate uridyltransferase (GALT; EC 2.7.712), results in an impaired galactose metabolism and serious long-term developmental affection of the CNS and ovaries, potentially related in part to endogenous galactose-induced protein dysglycosylation. In search for galactose-induced changes in membrane raft proteomes of GALT-deficient cells, we performed differential analyses of lipid rafts from patient-derived (Q) and sex- and age-matched control fibroblasts (H) in the presence or absence of the stressor. Label-based proteomics revealed of the total 454 (female) or 678 (male) proteins a proportion of ∼12% in at least one of four relevant ratios as fold-changed. GALT(-) cell-specific effects in the absence of stressor revealed cell-model-dependent affection of biological processes related to protein targeting to the plasma membrane (female) or to cellular migration (male). However, a series of common galactose-induced effects were observed, among them the strongly increased ER-stress marker GRP78 and calreticulin involved in N-glycoprotein quality control. The membrane-anchored N-glycoprotein receptor CD109 was concertedly decreased under galactose-stress together with cadherin-13, GLIPR1, glypican-1, and semaphorin-7A. A series of proteins showed opposite fold-changes in the two cell models, whereas others fluctuated in only one of the two models.

  5. Molecular and physiological responses of sunflower (helianthus annuus l.) to pgpr and sa under salt stress

    International Nuclear Information System (INIS)

    Naz, R.

    2015-01-01

    This paper presents the efficacy of PGPR (Azospirillum and Pseudomonas) and its modulation by salicylic acid. Two hybrids of sunflower (Hysun and Parsun) were inoculated with Azospirillum spp. and Pseudomonas spp. prior to sowing. Salt stress (20 dSm-1) was applied 28 d after sowing followed by foliar spray of salicylic acid (100 micro M) after 4 h of salt treatment. Azospirillum and Pseudomonas inoculation alone and in combination with salicylic acid alleviated the effects of salt stress on both the sunflower hybrids. The salt tolerance in these treatments was mediated by an increase in relative water content, carotenoids, proline, ABA, induction of new polypeptide bands and yield of sunflower hybrids. In response to salt stress four new polypeptide bands were synthesized in both Hysun, whereas, a group of six polypeptide bands were observed in Parsun. Application of salicylic acid alone and in combination with Azospirillum found to induce four new polypeptide bands in Hysun and Parsun. It is inferred that synthesis of new proteins in response to the combined application of salicylic acid and Azospirillum under salt stress, may play an important role as stress proteins in tolerance of sunflower hybrids to salt stress. (author)

  6. Renal Effects and Underlying Molecular Mechanisms of Long-Term Salt Content Diets in Spontaneously Hypertensive Rats.

    Directory of Open Access Journals (Sweden)

    Rebeca Caldeira Machado Berger

    Full Text Available Several evidences have shown that salt excess is an important determinant of cardiovascular and renal derangement in hypertension. The present study aimed to investigate the renal effects of chronic high or low salt intake in the context of hypertension and to elucidate the molecular mechanisms underlying such effects. To this end, newly weaned male SHR were fed with diets only differing in NaCl content: normal salt (NS: 0.3%, low salt (LS: 0.03%, and high salt diet (HS: 3% until 7 months of age. Analysis of renal function, morphology, and evaluation of the expression of the main molecular components involved in the renal handling of albumin, including podocyte slit-diaphragm proteins and proximal tubule endocytic receptors were performed. The relationship between diets and the balance of the renal angiotensin-converting enzyme (ACE and ACE2 enzymes was also examined. HS produced glomerular hypertrophy and decreased ACE2 and nephrin expressions, loss of morphological integrity of the podocyte processes, and increased proteinuria, characterized by loss of albumin and high molecular weight proteins. Conversely, severe hypertension was attenuated and renal dysfunction was prevented by LS since proteinuria was much lower than in the NS SHRs. This was associated with a decrease in kidney ACE/ACE2 protein and activity ratio and increased cubilin renal expression. Taken together, these results suggest that LS attenuates hypertension progression in SHRs and preserves renal function. The mechanisms partially explaining these findings include modulation of the intrarenal ACE/ACE2 balance and the increased cubilin expression. Importantly, HS worsens hypertensive kidney injury and decreases the expression nephrin, a key component of the slit diaphragm.

  7. MOVING FROM HISTOPATHOLOGY TO MOLECULAR TOOLS IN THE DIAGNOSIS OF MOLLUSKS DISEASES OF CONCERN UNDER EU LEGISLATION

    Directory of Open Access Journals (Sweden)

    Raquel Aranguren

    2016-11-01

    Full Text Available One of the main factors limiting molluscs production is the presence of pathogens and diseases. Disease agent transfer via transfers of live molluscs has been a major cause of disease outbreaks and epizootics. Because of that, the European Union has adopted several decisions and directives, the last in 2006 (2006/88/EC to control movements of marine organisms over the European countries. Once the disease is established in a determined area its eradication is a complicated task because life cycle of pathogens are not completely known and only a good and early diagnosis of the disease could be the most appropriate way to deal with it. Besides, molluscs do not have an adaptive immune response and vaccination strategies are not possibleMolluscs listed diseases under EU legislation are mainly protozoan parasites, that’s why histological techniques are recognized for their diagnosis. However, molecular techniques are being increasingly used primarily as confirmatory techniques of the presence of the pathogens but also in disease monitoring programs. Research perspectives are mainly focussed in the optimization, of the already described techniques to gain in sensitivity and sensibility and in the development of new molecular biology techniques (quantitative real time PCRs, that are faster and easier to apply and that allow a positive diagnosis even in early stages of infection. However, molecular tools detect DNA sequences of the pathogen which does not imply that pathogen is viable in the cell host and the infection is established. Consequently, it needs to be validated against other techniques, such as histology or in situ hybridization, so that its reliability can be determined.

  8. On the significance of incorporating shoreline changes for evaluating coastal hydrodynamics under sea level rise scenarios

    Science.gov (United States)

    Passeri, D.; Hagen, S. C.; Medeiros, S. C.

    2013-12-01

    Sea level rise (SLR) threatens coastal environments with loss of land, inundation of coastal wetlands, and increased flooding during extreme storm events. Research has shown that SLR is a major factor in the long-term, gradual retreat of shorelines (Fitzgerald et al., 2008). Along sandy shorelines, retreat has a more dynamic effect than just inundation due to rising water levels, including the physical process of erosion in which sand is removed from the shoreface and deposited offshore. This has the potential to affect ecological habitats as well as coastal communities. Although SLR induces seaward retreat of shorelines, many shorelines especially within the vicinity of inlets may experience accretion due to sediment trapping or beach replenishment (Aubrey and Giese, 1993, Browder and R.G., 1999). This study examines the influence of including projected shoreline changes under future sea states into hydrodynamic modeling within the Northern Gulf of Mexico (NGOM). The NGOM coastline is an economically and ecologically significant area, comprised of various bays, barrier islands and mainland beaches. Projected shorelines and nearshore morphology for the year 2050 are derived from the Coastal Vulnerability Index (CVI) shoreline change rates (Thieler and Hammer-Klose, 1999) and used in conjunction with the 'Bruun Rule effect'(Bruun, 1962). A large scale hydrodynamic model forced by astronomic tides and hurricane winds and pressures is used to simulate present conditions, a high projection of the 2050 sea state (18 in of SLR in accordance with Parris et al. (2012)) and the 2050 high sea state with 2050 shorelines to test the sensitivity of the system to the projected shoreline changes. Results show that shoreline changes coupled with sea level rise increases tidal inundation along shorelines, amplifies overtopping of barrier islands during storm surge events, and heightens inland storm surge inundation. It is critical to include estimates of shoreline and barrier

  9. Response of sunflower hybrids to different nitrogen levels for physiological and agronomical traits under field conditions

    International Nuclear Information System (INIS)

    Baig, D.; Abbasi, F.M.; Ahmed, H.; Qamar, M.; Khan, M.A.

    2016-01-01

    Sunflower occupies main position among oil seed crops in Pakistan. Mostly indigenous sunflower hybrids are cultivated which give low achene and fodder yields. The issue related with these hybrids ascribed to lack of information about use of inputs and cultural practices. Judicious nitrogen use and suitable high yielding hybrid play key role in increasing sunflower productivity. Protein is the basic requirement of the metabolic processes for the vegetative, reproductive growth and yield of the crop. The protein is wholly dependent upon the amount of nitrogen fertilization available in soil for the plant use. A two year study was conducted in 2012 and 2013 at National Agricultural Research Centre (NARC), Islamabad, Pakistan. The experiment was aimed to evaluate the effect of different nitrogen (N) levels (N = 0 kgha , N = 60 kgha , N = 0 1 2 -1 -1 -1 -1 80 kgha , N3 = 120 kgha , N4 = 180 kgha and N5 = 240 kgha ) on two sunflower hybrids, SMH-0907 and SMH-0917 to optimize the N levels for obtaining maximum yield on sustainable basis. Both hybrids were kept in the main plot while N levels in the sub plot in a randomized complete block design with three replications. -1 The results showed that the number of achene head , 100-achene weight and achene yield increased with increased N application. The increased levels of N -1 also enhanced the achene yield. The maximum achene yield (3170.8 kg ha ) was -1 -1 recorded at 180 kg N ha followed by 240 kg N ha . Minimum achene yield (2115 kg -1 ha ) was observed in control treatment (N ). Polynomial regression line showed 0-1 that the rate of yield increase was higher up to 180 kg N ha and become slow-1 thereafter. The hybrid SMH-0907 produced more achene (2736 kg ha ) as compared -1 to the hybrid SMH-0917 (2694 kg ha ). Results revealed that economized application of different doses of N can boost up the yield in both sunflower hybrids SMH-0907 and SMH-0917. These findings could be helpful in rationalizing most valuable inputs

  10. Soil concentration of glyphosate and AMPA under rice cultivation with contrasting levels of fertilization

    Science.gov (United States)

    Rey Montoya, Tania; Micaela Biassoni, María; Graciela Herber, Luciana; De Geronimo, Eduardo; Aparicio, Virginia

    2017-04-01

    Rice (Oryza sativa) is the world's most important crop species and occupies c. 150 mill ha. The province of Corrientes in Argentina leads the national production of rice cultivation. Glyphosate is a non-selective herbicide commonly used to control weeds. The molecule is inactivated once applied due to its adsorption in the soil, and once desorbed is degraded by soil microflora resulting in sarcosine and aminomethylphosphoric acid (AMPA) molecules. The objective of this investigation was to compare glyphosate and AMPA concentration in soil under different levels of fertilization along the growth season of the rice crop. A field experiment following a completely randomized design was carried out with four replicates. We evaluated four levels of fertilization (0-18-40): Control: 0 kg ha-1, Dose 1: 120 kg ha-1, Dose 2: 150 kg ha-1, Dose 3: 180 kg ha-1; and two levels of Glyphosate: with (Gly) or without (No) application. Four sampling moments were defined: pre-sowing (taken as reference), vegetative stage (V4, 30 days after application), in floral primordial differentiation-DPF (80 days post-application), and at physiological maturity-MF (125 days after application). Flooding was applied in V4 after sampling. The method used for determination and quantification was by ultra high-pressure liquid chromatography coupled to ESI UHPLC-MS / MS tandem mass spectrometer (+/-) (Acquit-Quattro Premier). We found that glyphosate and AMPA varied their concentration in soil according to the time of sampling. Detected levels of both molecules at pre-sowing indicate the persistence of this herbicide from earlier crop seasons. The highest concentration was measured in MF followed by V4. Interestingly, AMPA concentration showed higher values in V4 without application compared to the treatment with glyphosate application. On the other hand, in flooded soil both molecules presented a decrease in their concentration probably because of their dilution in water, increasing it again after

  11. The vegetative development of Sinningia leucotricha Hoehne (Moore under different levels of shading

    Directory of Open Access Journals (Sweden)

    Lilian Keiko Unemoto

    2010-02-01

    Full Text Available This work aimed at the assessment of the influence of different levels of shading in the development of (Sinningia leucotricha Hoehne (Moore. Tuberous roots of 2.3 ± 0.3 cm in diameter were used as vegetative material. The cultivation was performed in plastic vases and gross sand as substrate, and conditioned in sheltered nurseries protected by black polypropylene nets in the followings percentages: 0% (under full sunlight, 50, 60, and 70%. Sheltered nurseries with 60 or 70% of shading presented the highest vegetative development for Brazilian edelweiss. The cultivation of this species under full sunlight is not recommended.A rainha-do-abismo (Sinningia leucotricha Hoehne (Moore é uma planta nativa do Estado do Paraná, se destaca pela beleza de suas folhas de aspecto prateado. Este trabalho teve como objetivo avaliar a influência de diferentes níveis de sombreamento no desenvolvimento de plantas de rainha-do-abismo. Para o experimento foram utilizadas como material vegetativo raízes tuberosas com 2,3 ± 0,3 cm de diâmetro. O cultivo foi realizado em vasos plásticos e areia grossa como substrato, que foram acondicionados em viveiros protegidos com tela de polipropileno de coloração preta, nas seguintes porcentagens: 0% (a pleno sol 50%, 60% e 70%. Viveiros protegidos com 60% ou 70% de sombreamento foram os que proporcionaram maior desenvolvimento vegetativo de rainha-do-abismo. O cultivo desta espécie a pleno sol não é recomendado.

  12. Multiphoton-resonance-induced fluorescence of a strongly driven two-level system under frequency modulation

    Science.gov (United States)

    Yan, Yiying; Lü, Zhiguo; Luo, JunYan; Zheng, Hang

    2018-03-01

    We study the fluorescence spectrum of a strongly driven two-level system (TLS) with modulated transition frequency, which is a bichromatically driven TLS and has multiple resonance frequencies. We are aiming to provide a reliable description of the fluorescence in a regime that is difficult to tackle with perturbation theory and the rotating-wave approximation (RWA), and illustrate the spectral features of the fluorescence under off- and multiphoton-resonance conditions. To go beyond the RWA, we use a semianalytical counter-rotating-hybridized rotating-wave method that combines a unitary transformation and Floquet theory to calculate the two-mode Floquet states and quasienergies for the bichromatically driven TLS. We then solve the master equation accounting for the spontaneous decay in the bases of the two-mode Floquet states, and derive a physically transparent fluorescence spectrum. In comparison with the numerically exact spectrum from the generalized Floquet-Liouville approach, the present spectrum is found to be applicable in a wide range of the parameters where the RWA and the secular approximation may break down. We find that the counter-rotating (CR) terms of the transverse field omitted in the RWA have non-negligible contributions to the spectrum under certain conditions. Particularly, at the multiphoton resonance the width of which is comparable with the Bloch-Siegert shift, the RWA and non-RWA spectra markedly differ from each other because of the CR-induced shift. We also analyze the symmetry of the spectrum in terms of the transition matrix elements between the two-mode Floquet states. We show that the strict symmetry of the spectrum cannot be expected without the RWA but the almost symmetric spectrum can be obtained at the single-photon resonance that takes the Bloch-Siegert shift into account if the driving is moderately strong and at the multiphoton resonance with a sufficiently weak transverse field.

  13. Nonequilibrium molecular dynamics study of ring polymer melts under shear and elongation flows: A comparison with their linear analogs

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jeongha; Kim, Jinseong; Baig, Chunggi, E-mail: cbaig@unist.ac.kr [Department of Chemical Engineering, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798 (Korea, Republic of)

    2016-07-15

    We present detailed results for the structural and rheological properties of unknotted and unconcatenated ring polyethylene (PE) melts under shear and elongation flows via direct atomistic nonequilibrium molecular dynamics simulations. Short (C{sub 78}H{sub 156}) and long (C{sub 400}H{sub 800}) ring PE melts were subjected to planar Couette flow (PCF) and planar elongational flow (PEF) across a wide range of strain rates from linear to highly nonlinear flow regimes. The results are analyzed in detail through a direct comparison with those of the corresponding linear polymers. We found that, in comparison to their linear analogs, ring melts possess rather compact chain structures at or near the equilibrium state and exhibit a considerably lesser degree of structural deformation with respect to the applied flow strength under both PCF and PEF. The large structural resistance of ring polymers against an external flow field is attributed to the intrinsic closed-loop configuration of the ring and the topological constraint of nonconcatenation between ring chains in the melt. As a result, there appears to be a substantial discrepancy between ring and linear systems in terms of their structural and rheological properties such as chain orientation, the distribution of chain dimensions, viscosity, flow birefringence, hydrostatic pressure, the pair correlation function, and potential interaction energies. The findings and conclusions drawn in this work would be a useful guide in future exploration of the characteristic dynamical and relaxation mechanisms of ring polymers in bulk or confined systems under flowing conditions.

  14. Selected materials of the international workshop on radiation risk and its origin at molecular and cellular level

    International Nuclear Information System (INIS)

    Pinak, Miroslav

    2003-11-01

    The workshop ''International Workshop on Radiation Risk and its Origin at Molecular and Cellular Level'' was held at The Tokai Research Establishment, Japan Atomic Energy Research Institute, on the 6th and 7th of February 2003. The Laboratory of Radiation Risk Analysis of JAERI organized it. This international workshop attracted scientists from several different scientific areas, including radiation physics, radiation biology, molecular biology, crystallography of biomolecules, modeling and bio-informatics. Several foreign and domestic keynote speakers addresses the very fundamental areas of radiation risk and tried to establish a link between the fundamental studies at the molecular and cellular level and radiation damages at the organism. The symposium consisted of 13 oral lectures, 10 poster presentations and panel discussion. The 108 participants attended the workshop. This publication comprises of proceedings of oral and poster presentations where available. For the rest of contributions the abstracts or/and selections of presentation materials are shown instead. The 5 papers are indexed individually. (J.P.N.)

  15. Molecular responses during cadmium-induced stress in Daphnia magna: Integration of differential gene expression with higher-level effects

    Energy Technology Data Exchange (ETDEWEB)

    Soetaert, Anneleen [Department of Biology, Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)]. E-mail: anneleen.soetaert@ua.ac.be; Vandenbrouck, Tine [Department of Biology, Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Ven, Karlijn van der [Department of Biology, Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Maras, Marleen [Department of Biology, Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Remortel, Piet van [Department of Mathematics and Informatics, Intelligent Systems Laboratory, University of Antwerp, Middelheimlaan 1, B-2020 Antwerp (Belgium); Blust, Ronny [Department of Biology, Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Coen, Wim M. de [Department of Biology, Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2007-07-20

    DNA microarrays offer great potential in revealing insight into mechanistic toxicity of contaminants. The aim of the present study was (i) to gain insight in concentration- and time-dependent cadmium-induced molecular responses by using a customized Daphnia magna microarray, and (ii) to compare the gene expression profiles with effects at higher levels of biological organization (e.g. total energy budget and growth). Daphnids were exposed to three cadmium concentrations (nominal value of 10, 50, 100 {mu}g/l) for two time intervals (48 and 96 h). In general, dynamic expression patterns were obtained with a clear increase of gene expression changes at higher concentrations and longer exposure duration. Microarray analysis revealed cadmium affected molecular pathways associated with processes such as digestion, oxygen transport, cuticula metabolism and embryo development. These effects were compared with higher-level effects (energy budgets and growth). For instance, next to reduced energy budgets due to a decline in lipid, carbohydrate and protein content, we found an up-regulated expression of genes related to digestive processes (e.g. {alpha}-esterase, cellulase, {alpha}-amylase). Furthermore, cadmium affected the expression of genes coding for proteins involved in molecular pathways associated with immune response, stress response, cell adhesion, visual perception and signal transduction in the present study.

  16. [Research on promotory effect of traditional Chinese medicine on fracture healing in cell and molecular level].

    Science.gov (United States)

    Zhang, Kun; Niu, Liang-Chen; Yuan, Fu-Jie; Liu, Shen-Peng

    2017-08-25

    Traditional Chinese medicine is widely used in the treatment of fractures, osteoporosis, other bone related diseases for thousands of years. There are many animal experiments and clinical trials demonstrating that the traditional Chinese medicine such as epimedium, Drynaria and other traditional Chinese medicine can stimulate bone regeneration and inhibit bone resorption, accelerating the fracture healing. In recent years many cell experiments have shown that these herbal ingredients up-regulated the expression of intracellular osteogenic transcription factors and osteogenic related genes, and then induced osteoblastic differentiation and stimulated the proliferation of osteoblasts, bone nodule formation and matrix mineralization. Meanwhile these herbal ingredients up-regulated the expression of intracellular osteoclastic transcription factors and osteoclast related genes, inhibited osteoclast differentiation and bone resorption of osteoclasts. In addition, intracellular signaling pathways regulated these herbal ingredients by might be involved in the above effects. We can have a conclusion that the genes expression regulated by transcription factors in pre-osteoblast and pre-osteoclast and these signaling pathways are the major molecular mechanisms and research hotspots of traditional Chinese medicine in promoting fracture healing. Based on these molecular mechanisms to review, this review provides not only the foundation for the study of traditional Chinese medicine in promoting fracture healing, but also the basis for clinical treatment of fracture. Copyright© 2017 by the China Journal of Orthopaedics and Traumatology Press.

  17. Expression profiling of a genetic animal model of depression reveals novel molecular pathways underlying depressive-like behaviours.

    Directory of Open Access Journals (Sweden)

    Ekaterini Blaveri

    2010-09-01

    Full Text Available The Flinders model is a validated genetic rat model of depression that exhibits a number of behavioural, neurochemical and pharmacological features consistent with those observed in human depression.In this study we have used genome-wide microarray expression profiling of the hippocampus and prefrontal/frontal cortex of Flinders Depression Sensitive (FSL and control Flinders Depression Resistant (FRL lines to understand molecular basis for the differences between the two lines. We profiled two independent cohorts of Flinders animals derived from the same colony six months apart, each cohort statistically powered to allow independent as well as combined analysis. Using this approach, we were able to validate using real-time-PCR a core set of gene expression differences that showed statistical significance in each of the temporally distinct cohorts, representing consistently maintained features of the model. Small but statistically significant increases were confirmed for cholinergic (chrm2, chrna7 and serotonergic receptors (Htr1a, Htr2a in FSL rats consistent with known neurochemical changes in the model. Much larger gene changes were validated in a number of novel genes as exemplified by TMEM176A, which showed 35-fold enrichment in the cortex and 30-fold enrichment in hippocampus of FRL animals relative to FSL.These data provide significant insights into the molecular differences underlying the Flinders model, and have potential relevance to broader depression research.

  18. An update on potential molecular mechanisms underlying the actions of snake venom L-amino acid oxidases (LAAOs).

    Science.gov (United States)

    Paloschi, Mauro Valentino; Pontes, Adriana Silva; Soares, Andreimar Martins; Zuliani, Juliana Pavan

    2017-11-08

    LAAOs (EC 1.4.3.2) are found in concentrations that vary according to each species of snakes; Viperidae, Crotalidae and Elapidae contain 1-9% of this enzyme in their venoms. This review focuses on an update on molecular mechanisms, platelet activities, antimicrobial, antiprotozoal, induction of apoptosis and inflammatory potential underlying the actions of SV-LAAOs. Snake venom LAAOs (SV-LAAOs) have become an interesting subject for pharmacological, structural and molecular studies. Although the mechanisms of action of these enzymes are not well understood they are a subject of a variety of studies, because LAAOs are multifunctional enzymes exhibiting a wide range of pharmacological effects, including the inhibition or induction of platelet aggregation, hemolysis and hemorrhage, in addition to the stimulation of apoptosis, the activation of leukocytes and the formation of edema. Moreover, SV-LAAOs play an important role in bactericidal, cytotoxic, anti-parasitic, anti-tumor, and antiviral activities. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  19. Physiological and molecular responses to bariatric surgery: markers or mechanisms underlying T2DM resolution?

    Science.gov (United States)

    Hutch, Chelsea R; Sandoval, Darleen A

    2017-03-01

    Bariatric surgery is currently the most effective treatment for obesity and associated comorbidities, including rapid resolution of type 2 diabetes mellitus (T2DM). Although the weight loss itself has substantial impact, bariatric surgery also has weight loss-independent effects on T2DM. Several variations of bariatric surgery exist, including the widely studied Roux-en-Y gastric bypass and vertical sleeve gastrectomy. The success of both of these bariatric surgeries was originally attributed to restrictive and malabsorptive modes of action; however, mounting evidence from both human and animal studies implicates mechanisms beyond surgery-induced mechanical changes to the gastrointestinal (GI) system. In fact, with bariatric surgery comes a spectrum of physiological responses, including postprandial enhancement of gut peptide and bile acids levels, restructuring of microbial composition, and changes in GI function and morphology. Although many of these processes are also essential for glucoregulation, the independent role of each in the success of surgery is still an open question. In this review, we explore whether these changes are necessary for the improvements in body mass and glucose homeostasis or whether they are simply markers of the physiological effect of surgery. © 2016 New York Academy of Sciences.

  20. Molecular Mechanisms Underlying the Anti-depressant Effects of Resveratrol: a Review.

    Science.gov (United States)

    de Oliveira, Marcos Roberto; Chenet, Aline Lukasievicz; Duarte, Adriane Ribeiro; Scaini, Giselli; Quevedo, João

    2017-07-10

    Major depression is a public health problem, affecting 121 million people worldwide. Patients suffering from depression present high rates of morbidity, causing profound economic and social impacts. Furthermore, patients with depression present cognitive impairments, which could influence on treatment adherence and long-term outcomes. The pathophysiology of major depression is not completely understood yet but involves reduced levels of monoamine neurotransmitters, bioenergetics, and redox disturbances, as well as inflammation and neuronal loss. Treatment with anti-depressants provides a complete remission of symptoms in approximately 50% of patients with major depression. However, these drugs may cause side effects, as sedation and weight gain. In this context, there is increasing interest in studies focusing on the anti-depressant effects of natural compounds found in the diet. Resveratrol is a polyphenolic phytoalexin (3,4',5-trihydroxystilbene; C 14 H 12 O 3 ; MW 228.247 g/mol) and has been found in peanuts, berries, grapes, and wine and induces anti-oxidant, anti-inflammatory, and anti-apoptotic effects in several mammalian cell types. Resveratrol also elicits anti-depressant effects, as observed in experimental models using animals. Therefore, resveratrol may be viewed as a potential anti-depressant agent, as well as may serve as a model of molecule to be modified aiming to ameliorate depressive symptoms in humans. In the present review, we describe and discuss the anti-depressant effects of resveratrol focusing on the mechanism of action of this phytoalexin in different experimental models.

  1. Estuarine sediment resuspension and acidification: Release behaviour of contaminants under different oxidation levels and acid sources.

    Science.gov (United States)

    Martín-Torre, M Camino; Cifrian, Eva; Ruiz, Gema; Galán, Berta; Viguri, Javier R

    2017-09-01

    Carbon dioxide (CO 2 ) Capture and Storage (CCS) is a technology to reduce the emissions of this gas to the atmosphere by sequestering it in geological formations. In the case of offshore storage, unexpected CO 2 leakages will acidify the marine environment. Reductions of the pH might be also caused by anthropogenic activities or natural events such as acid spills and dredging operations or storms and floods. Changes in the pH of the marine environment will trigger the mobilisation of elements trapped in contaminated shallow sediments with unclear redox boundary. Trace element (As, Cd, Cr, Cu, Ni, Pb and Zn) release from anoxic and oxic estuarine sediment is analysed and modelled under different laboratory acidification conditions using HNO 3 (l) and CO 2 (g): acidification at pH = 6.5 as worst-case scenario in events of CO 2 leakages and acid spills, and acidification at pH = 7.0 as a seawater scenario under CO 2 leakages, acid spills, as well as sediment resuspension. The prediction of metal leaching behaviour appear to require sediment specific and site specific tools. In the present work it is demonstrated that the proposed three in-series reactions model predicts the process kinetics of the studied elements under different simulated environmental conditions (oxidation levels and acid sources). Differences between HNO 3 and CO 2 acidification are analysed through the influence of the CO 2 gas on the ionic competition of the medium. The acidification with CO 2 provokes higher released concentrations from the oxic sediment than from the anoxic sediment, except in the case of Zn, which influences the release of the other studied elements. Slight acidification can endanger the aquatic environment through an important mobilisation of contaminants. The obtained prediction of the contaminant release from sediment (kinetic parameters and maximum concentrations) can contribute to the exposure assessment stage for risk management and preincidental planning in

  2. Pressure-induced metallization of condensed phase β-HMX under shock loadings via molecular dynamics simulations in conjunction with multi-scale shock technique.

    Science.gov (United States)

    Ge, Ni-Na; Wei, Yong-Kai; Zhao, Feng; Chen, Xiang-Rong; Ji, Guang-Fu

    2014-07-01

    The electronic structure and initial decomposition in high explosive HMX under conditions of shock loading are examined. The simulation is performed using quantum molecular dynamics in conjunction with multi-scale shock technique (MSST). A self-consistent charge density-functional tight-binding (SCC-DFTB) method is adapted. The results show that the N-N-C angle has a drastic change under shock wave compression along lattice vector b at shock velocity 11 km/s, which is the main reason that leads to an insulator-to-metal transition for the HMX system. The metallization pressure (about 130 GPa) of condensed-phase HMX is predicted firstly. We also detect the formation of several key products of condensed-phase HMX decomposition, such as NO2, NO, N2, N2O, H2O, CO, and CO2, and all of them have been observed in previous experimental studies. Moreover, the initial decomposition products include H2 due to the C-H bond breaking as a primary reaction pathway at extreme condition, which presents a new insight into the initial decomposition mechanism of HMX under shock loading at the atomistic level.

  3. Classification of Partial Discharge Measured under Different Levels of Noise Contamination.

    Directory of Open Access Journals (Sweden)

    Wong Jee Keen Raymond

    Full Text Available Cable joint insulation breakdown may cause a huge loss to power companies. Therefore, it is vital to diagnose the insulation quality to detect early signs of insulation failure. It is well known that there is a correlation between Partial discharge (PD and the insulation quality. Although many works have been done on PD pattern recognition, it is usually performed in a noise free environment. Also, works on PD pattern recognition in actual cable joint are less likely to be found in literature. Therefore, in this work, classifications of actual cable joint defect types from partial discharge data contaminated by noise were performed. Five cross-linked polyethylene (XLPE cable joints with artificially created defects were prepared based on the defects commonly encountered on site. Three different types of input feature were extracted from the PD pattern under artificially created noisy environment. These include statistical features, fractal features and principal component analysis (PCA features. These input features were used to train the classifiers to classify each PD defect types. Classifications were performed using three different artificial intelligence classifiers, which include Artificial Neural Networks (ANN, Adaptive Neuro-Fuzzy Inference System (ANFIS and Support Vector Machine (SVM. It was found that the classification accuracy decreases with higher noise level but PCA features used in SVM and ANN showed the strongest tolerance against noise contamination.

  4. Paramecium tetraurelia growth stimulation under low-level chronic irradiation: investigations on a possible mechanism

    International Nuclear Information System (INIS)

    Croute, F.; Soleilhavoup, J.P.; Vidal, S.; Dupouy, D.; Planel, H.

    1982-01-01

    Experiments were carried out to demonstrate the effects of low-level chronic irradiation on Paramecium tetraurelia proliferation. Biological effects were strongly dependent on the bacterial density of culture medium and more exactly on the catalase content of the medium. Significant growth stimulation was found under 60 Co chronic irradiation at a dose rate of 2 rad/year when paramecia were grown in a medium containing a high bacterial concentration (2.5 x 10 2 cells/m) or supplemented with catalase (300 U/ml). In a medium with a low bacterial density (1 x 10 6 cell/ml) or supplemented with a catalase activity inhibitor, growth simulation was preceded by a transitory inhibiting effect which could be correlated with extracellularly radioproduced H 2 O 2 . H 2 O 2 addition appeared to be able to simulate the biological effects of chronic irradiation. A possible mechanism is discussed.We proposed that the stimulating effects were the result of intracellular enzymatic scavenging of radioproduced H 2 O 2

  5. Response of aquatic macrophyte biomass to limnological changes under water level fluctuation in tropical reservoirs

    Directory of Open Access Journals (Sweden)

    E. G. Moura Júnior

    2018-03-01

    Full Text Available Abstract We evaluated the response of the biomass of aquatic macrophytes under limnological changes after water level fluctuation (WLF of two tropical reservoirs (R1 and R2, located in northeastern Brazil. Initially we tested the hypothesis that post-WLF limnological conditions and biomass of macrophytes increase or decrease, depending on the variable or species. We monitored a 4 × 50 m permanent plot, in four expeditions per period (pre- or post-WLF, assessing species biomass and 10 limnological variables. We utilized 0.25 × 0.25 m quadrats for biomass. Once the effect of WLF in limnological variables and species biomass was confirmed, we utilized Canonical Correspondence Analysis to understand the relationship between limnological variables and species biomass. The abundant and/or dominant species in pre-WLF of R1 ( Pistia stratiotes, Eichhornia crassipes and Salvinia auriculata and R2 (Paspalidium geminatum and S. auriculata reduced their biomass post-WLF and were correlated with temperature, total phosphorous and nitrate. The reduced biomass of P. stratiotes, E. crassipes and S. auriculata in post-WLF widened resource availability, allowing coexistence of species. Therefore, we suggest that the change of limnological conditions in post-WLF in artificial lakes acts only as a moderator factor of the interspecific interaction (especially coexistence, without direct relation between these conditions and species biomass.

  6. Rooting Ability of Melia volkensii Cuttings Under Different Auxin Concentration Levels and Provenances

    International Nuclear Information System (INIS)

    Oeba, V.O; Muok, B.; Odee, D

    2007-01-01

    Melia volkensii is one of the most popular fast growing agro-forestry tree species in East Africa's arid and semi arid lands. It is valued for for production of termite resistant timber. Kenya Forestry Research Institute is carrying out studies on management, improvement and domestication of species with a major focus on improving low germination mortality and other propagation methods. Vegetative propagation was investigated in order to supplement more seedlings for increased demand of the species. The objective of this study was to determine and predict the effect of varying levels of auxin concentrations on rooting of melia volkensii shoot cuttings under different provenances. The experiment was set in a split plot design and conducted in a non-mist propagator. The number of roots was recorded for every cutting in the experiment. Mean cumulative cutting percentage were analysed using ANOVA procedures by first checking homogeneity of variance; Pearson correlation were carried out to check the interrelation of the factors with rooting and Logistic ability of the cuttings. The results showed that cuttings inoculated with 0.3 mgl-1 s ignificantly (p n ot showing any rooting from three provenances. In conclusion 0.03 mgl-1 s hould be used for further vegetative propagation of M. vokensii. Cutting from Taveta inoculated with 0.3 mgl-1 w ould significantly increase the number of seedlings for planting

  7. Design rules for piping: plastic stability of straight parts under level d loadings

    International Nuclear Information System (INIS)

    Touboul, F.; Ben Jdidia, M.; Acker, D.

    1989-01-01

    For piping systems, design rules for straight parts, under static loads are based on limit analysis. We have studied the accuracy of such method when different geometries and combinations of loadings are concerned. Analysing theoretical computations, we have pointed out the hypothesis inherent to the formulation used in design codes (ASME, RCCM, RCC-MR). We have determined a formula closer to the theoretical results that we have compared to experiments. We have interpreted up to 170 tests from different laboratories with varied geometries (D/e from 10 to 115) and manifold type of loadings, with or without pressure: pure bending, pure torsion, bending with torsion, combined bending. We have applied the codes rules and we have noticed that for certain tests, experimental ultimate moments were fourty per cent lower than the coded one. As geometry is concerned, contrary to the limit analysis prediction, ultimate load does not depend only on the modulus of inertia (Z) but also on the D/e ratio by a (D/e) .33 coefficient. As level D service limits were considered, we have taken out the maximal load borne by the tubes. To ensure the conservatism of the rule, the allowable stress for austenitic steels, as defined by codes, must be taken at the value defined by ASME, Section III, Appendix F (criteria for component, F 1331)

  8. Certain growth related attributes of micropropagated banana under different salinity levels

    International Nuclear Information System (INIS)

    Haq, I.U.; Soomro, F.

    2011-01-01

    The effect of salinity (NaCl) was assessed on banana (Musa spp.) cv., Sindhri Banana (Basrai) propagating plantlets in aseptic condition. Four different NaCl levels [0 (control) 50, 100 and 150 mM] were maintained at shoot multiplication stage for 6-weeks. Salinity reduced the number of plantlets per explants and plant biomass significantly. A proportional relationship was observed for Na/sup +/ and Cl/sub -/ but K/sup +/, Ca/sup 2+/and NO/sub 3/ were observed to be inversely proportioned with NaCl stress. Similarly, total proteins as well as carbohydrate contents were decreased significantly. Increasing mode of secondary metabolites (proline, betaine contents and reducing sugars) were showing a negative relationship of saline stress with plant micro-propagation efficiency. Among photosynthetic pigments, total carotenoids were increased while chlorophyll contents (Chl a and b) decreased. Similarly, nitrate reductase activity also reduced. Overall, vegetative propagation of banana was affected significantly by NaCl stress under in-vitro conditions. (author)

  9. On optimal upgrade level for used products under given cost structures

    International Nuclear Information System (INIS)

    Shafiee, Mahmood; Finkelstein, Maxim; Chukova, Stefanka

    2011-01-01

    In spite of the growing share of the second-hand market, often customers of used products encounter the following three problems: (a) they are uncertain regarding the durability and performance of these products due to lack of information on the item's past usage and maintenance history, (b) they are uncertain about the accurate pricing of warranties and the post-warranty repair costs, and (c) sometimes, right after the sale, used items may have high failure rate and could be harmful to their new owner. Due to these problems, the dealers are currently carrying out actions such as overhaul and upgrade of the used products before their release. Reliability improvement, which is closely related to the concept of warranty, for used products is a relatively new concept and has received very limited attention. This paper also develops a stochastic model which results in the derivation of the optimal expected upgrade level under given structures of the profit and failure rate functions. We provide a numerical study to illustrate our results.

  10. Agronomic performances of three vetch species growing under different drought levels

    Directory of Open Access Journals (Sweden)

    Sywar Haffani

    2014-09-01

    Full Text Available The current challenge of agriculture is to get the best yields while overcoming frequent water deficit conditions. The objective of this study was to compare performances of three vetch species (Vicia narbonensis L., V. sativa L., and V. villosa Roth subjected to water stress. Plants were sown in pots under rainout shelter and submitted to four water regimes: control (100% field capacity [FC], 80%, 60%, and 40% FC through 3 yr experiment. Results showed that V. narbonensis had the smallest declines in all the studied variables in response to water restriction but the highest water use efficiency (WUE and stress tolerance index (STI in both control and water-treated plants. This indicates the greater tolerance of this species to water constraint and its better water use. Vicia villosa was characterized by drastic declines in leaf area and DM yield (75% and 64%, respectively. It had also the smallest WUE and STI suggesting its low adaptation to water stress. Vicia sativa showed severe reductions in seed yield and yield components; accordingly, it was the most sensitive species in terms of seed yield. The three species implied avoidance strategies to cope with water stress. The different levels of drought tolerance explain the species ecological distribution in Tunisia.

  11. Assessing economic impact of storm surge under projected sea level rise scenarios

    Science.gov (United States)

    Del Angel, D. C.; Yoskowitz, D.

    2017-12-01

    Global sea level is expected to rise 0.2-2m by the year 2100. Rising sea level is expected to have a number of impacts such as erosion, saltwater intrusion, and decline in coastal wetlands; all which have direct and indirect socio-economic impact to coastal communities. By 2050, 25% of the world's population will reside within flood-prone areas. These statistics raise a concern for the economic cost that sea level and flooding has on the growing coastal communities. Economic cost of storm surge inundation and rising seas may include loss or damage to public facilities and infrastructure that may become temporarily inaccessible, as well as disruptions to business and services. This goal of this project is to assess economic impacts of storms under four SLR scenarios including low, intermediate-low, intermediate-high, and high (0.2m, 0.5m, 1.2m and 2m, respectively) in the Northern Gulf of Mexico region. To assess flooding impact on communities from storm surge, this project utilizes HAZUS-MH software - a Geographic Information System (GIS)-based modeling tool developed by the Federal Emergency Management Agency - to estimate physical, economic, and social impacts of natural disasters such as floods, earthquakes and hurricanes. The HAZUS database comes integrated with aggregate and site specific inventory which includes: demographic data, general building stock, agricultural statistics, vehicle inventory, essential facilities, transportation systems, utility systems (among other sensitive facilities). User-defined inundation scenarios will serve to identify assets at risk and damage estimates will be generated using the Depth Damage Function included in the HAZUS software. Results will focus on 3 communities in the Gulf and highlight changes in storm flood impact. This approach not only provides a method for economic impact assessment but also begins to create a link between ecosystem services and natural and nature-based features such as wetlands, beaches and dunes

  12. Nutrient extraction and exportation by common bean cultivars under different fertilization levels: I - macronutrients

    Directory of Open Access Journals (Sweden)

    Rogério Peres Soratto

    2013-08-01

    Full Text Available The use of cultivars with a higher yield potential and the adoption of new technology have achieved high grain yields in common bean, which probably changed the demand for nutrients in this crop. However, there is almost no information about the periods of the cycle in which nutrients are most demanded at which quantities by the main cultivars. The objective of this study was to evaluate the macronutrient extraction and exportation by the common bean cultivars Pérola and IAC Alvorada, under different levels of NPK fertilization, on a dystroferric Red Nitosol, in Botucatu, São Paulo State, Brazil. The experiment was arranged in a randomized complete block (split plot design with four replications. The plots consisted of six treatments based on a 2 x 3 factorial model, represented by two cultivars and three NPK levels (PD0 - 'Pérola' without fertilization, PD1 - 'Pérola' with 50 % of recommended fertilization, PD2 - 'Pérola' with 100 % of recommended fertilization, AD0 - 'IAC Alvorada' without fertilization, AD1 - 'IAC Alvorada' with 50 % of recommended fertilization, and AD2 - 'IAC Alvorada' with 100 % of recommended fertilization and subplots sampled seven times during the cycle. At higher levels of NPK fertilization, the grain yield and macronutrient extraction and exportation of both cultivars were higher, but without statistical differences. Macronutrient absorption was higher in the treatments with 100 % of recommended NPK fertilization (average amounts per hectare: 140 kg N, 16.5 kg P, 120 kg K, 69 kg Ca, 17.9 kg Mg, and 16.3 kg S. Regardless of the treatment, the demand for N, P, K, Ca, and Mg was highest from 45 to 55 days after emergence (DAE, i.e., in the R7 stage (pod formation, while the highest S absorption rates were concentrated between 55 and 65 DAE. More than 70 % of P, between 58 and 69 % of N, 40 and 52 % of S, 40 and 48 % of K, and 35 and 45 % of Mg absorbed during the cycle was exported with grains, whereas less than 15

  13. Biochemistry and pharmacology of the myometrium and labor: regulation at the cellular and molecular levels.

    Science.gov (United States)

    Huszar, G; Roberts, J M

    1982-01-15

    This review presents the essentials of cell biology, biochemistry, and pharmacology of the myometrium and labor, especially as they relate to premature labor. The aim is to explore the neuroendocrine and pharmacologic regulation of myometrial muscle cells in the context of cell membrane function and contractile processes. In the first section, smooth muscle protein structure and interactions are described, the central roles of myosin light-chain kinase, calcium, and cyclic adenosine monophosphate (cAMP) are reviewed. Subsequently, events relating to hormone/drug receptor function and implications for pharmacologic applications are discussed. Finally, the processes of information transfer via hormones and drugs are incorporated into a model which explains how the hormones and drugs used in clinical practice may mediate myometrial contractility. The reader is introduced to current concepts of the cellular, molecular, and pharmacologic aspects of labor in order to facilitate the understanding of medical augmentation of labor and tocolytic therapy.

  14. Investigating carbon dynamics in Siberian peat bogs using molecular-level analyses

    Science.gov (United States)

    Kaiser, K.; Benner, R. H.

    2013-12-01

    Total hydrolysable carbohydrates, and lignin and cutin acid compounds were analyzed in peat cores collected 56.8 N (SIB04), 58.4 N (SIB06), 63.8 N (G137) and 66.5 N (E113) in the Western Siberian Lowland to investigate vegetation, chemical compositions and the stage of decomposition. Sphagnum mosses dominated peatland vegetation in all four cores. High-resolution molecular analyses revealed rapid vegetation changes on timescales of 50-200 years in the southern cores Sib4 and Sib6. Syringyl and vanillyl (S/V) ratios and cutin acids indicated these vegetation changes were due to varying inputs of angiosperm and gymnosperm and root material. In the G137 and E113 cores lichens briefly replaced sphagnum mosses and vascular plants. Molecular decomposition indicators used in this study tracked the decomposition of different organic constituents of peat organic matter. The carbohydrate decomposition index was sensitive to the polysaccharide component of all peat-forming plants, whereas acid/aldehyde ratios of S and V phenols (Ac/AlS,V) followed the lignin component of vascular plants. Low carbohydrate decomposition indices in peat layers corresponded well with elevated (Ad/Al)S,V ratios. This suggested both classes of biochemicals were simultaneously decomposed, and decomposition processes were associated with extensive total mass loss in these ombrotrophic systems. Selective decomposition or transformation of lignin was observed in the permafrost-influenced northern cores G137 and E113. Both cores exhibited the highest (Ad/Al)S,V ratios, almost four-fold higher than measured in peat-forming plants. The extent of decomposition in the four peat cores did not uniformly increase with age, but showed episodic extensive decomposition events. Variable decomposition events independent of climatic conditions and vegetation shifts highlight the complexity of peatland dynamics.

  15. Investigating the Interaction Pattern and Structural Elements of a Drug-Polymer Complex at the Molecular Level.

    Science.gov (United States)

    Nie, Haichen; Mo, Huaping; Zhang, Mingtao; Song, Yang; Fang, Ke; Taylor, Lynne S; Li, Tonglei; Byrn, Stephen R

    2015-07-06

    Strong associations between drug and polymeric carriers are expected to contribute to higher drug loading capacities and better physical stability of amorphous solid dispersions. However, molecular details of the interaction patterns and underlying mechanisms are still unclear. In the present study, a series of amorphous solid dispersions of clofazimine (CLF), an antileprosy drug, were prepared with different polymers by applying the solvent evaporation method. When using hypromellose phthalate (HPMCP) as the carrier, the amorphous solid dispersion system exhibits not only superior drug loading capacity (63% w/w) but also color change due to strong drug-polymer association. In order to further explain these experimental observations, the interaction between CLF and HPMCP was investigated in a nonpolar volatile solvent system (chloroform) prior to forming the solid dispersion. We observed significant UV/vis and (1)H NMR spectral changes suggesting the protonation of CLF and formation of ion pairs between CLF and HPMCP in chloroform. Furthermore, nuclear Overhauser effect spectroscopy (NOESY) and diffusion order spectroscopy (DOSY) were employed to evaluate the strength of associations between drug and polymers, as well as the molecular mobility of CLF. Finally, by correlating the experimental values with quantum chemistry calculations, we demonstrate that the protonated CLF is binding to the carboxylate group of HPMCP as an ion pair and propose a possible structural model of the drug-polymer complex. Understanding the drug and carrier interaction patterns from a molecular perspective is critical for the rational design of new amorphous solid dispersions.

  16. Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy: An analytical technique to understand therapeutic responses at the molecular level.

    Science.gov (United States)

    Kalmodia, Sushma; Parameswaran, Sowmya; Yang, Wenrong; Barrow, Colin J; Krishnakumar, Subramanian

    2015-11-16

    Rapid monitoring of the response to treatment in cancer patients is essential to predict the outcome of the therapeutic regimen early in the course of the treatment. The conventional methods are laborious, time-consuming, subjective and lack the ability to study different biomolecules and their interactions, simultaneously. Since; mechanisms of cancer and its response to therapy is dependent on molecular interactions and not on single biomolecules, an assay capable of studying molecular interactions as a whole, is preferred. Fourier Transform Infrared (FTIR) spectroscopy has become a popular technique in the field of cancer therapy with an ability to elucidate molecular interactions. The aim of this study, was to explore the utility of the FTIR technique along with multivariate analysis to understand whether the method has the resolution to identify the differences in the mechanism of therapeutic response. Towards achieving the aim, we utilized the mouse xenograft model of retinoblastoma and nanoparticle mediated targeted therapy. The results indicate that the mechanism underlying the response differed between the treated and untreated group which can be elucidated by unique spectral signatures generated by each group. The study establishes the efficiency of non-invasive, label-free and rapid FTIR method in assessing the interactions of nanoparticles with cellular macromolecules towards monitoring the response to cancer therapeutics.

  17. IS LAND LEVELLING IN VALLEY FLOORS A VIABLE OPTION FOR INCREASING CROP PRODUCTION UNDER RAINFED CONDITIONS OF POTHWAR PUNJAB, PAKISTAN

    OpenAIRE

    Shah, Nisar Ali; Sharif, Ch.M.; Akmal, Nadeem

    2004-01-01

    Population pressure on limited land resources pushed farmers to bring non-cultivated area of the rainfed Pothwar under arable farming. Land leveling options -are used by farmers extensively to bridge land resources inadequacy to ensure even a subsistence level of farming. The use of land leveling as a single solution is not endorsed by the soil and water conservation experts as against the development oriented public departments. The expensive and low paying nature of existing land leveling p...

  18. Changing of Bacteria Catalase Activity Under the Influence of Electro-Magnetic Radiation on a Frequency of Nitric Oxide Absorption and Radiation Molecular Spectrum

    Directory of Open Access Journals (Sweden)

    G.M. Shub

    2009-09-01

    Full Text Available The dynamics of catalase activity degree changing in Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa is described under the influence of electro-magnetic radiation on a frequency of nitric oxide absorption and radiation molecular spectrum. The panoramic spectrometric measuring complex, developed in Central Scientific Research Institute of measuring equipment Public corporation, Saratov, was used while carrying out the research. Electromagnetic vibrations of extremely high frequencies were stimulated in this complex imitating the structure of nitric oxide absorption and radiation molecular spectrum. The growth of activity of the mentioned enzyme of the strains under research was detected. The most significant changes were observed under 60-minutes exposure.

  19. Mathematical model and calculation algorithm of micro and meso levels of separation process of gaseous mixtures in molecular sieves

    Science.gov (United States)

    Umarova, Zhanat; Botayeva, Saule; Yegenova, Aliya; Usenova, Aisaule

    2015-05-01

    In the given article, the main thermodynamic aspects of the issue of modeling diffusion transfer in molecular sieves have been formulated. Dissipation function is used as a basic notion. The differential equation, connecting volume flow with the change of the concentration of catchable component has been derived. As a result, the expression for changing the concentration of the catchable component and the coefficient of membrane detecting has been received. As well, the system approach to describing the process of gases separation in ultra porous membranes has been realized and micro and meso-levels of mathematical modeling have been distinguished. The non-ideality of the shared system is primarily taken into consideration at the micro-level and the departure from the diffusion law of Fick has been taken into account. The calculation method of selectivity considering fractal structure of membranes has been developed at the meso level. The calculation algorithm and its software implementation have been suggested.

  20. Upregulation of interleukin-1β/transforming growth factor-β1 and hypoxia relate to molecular mechanisms underlying immobilization-induced muscle contracture.

    Science.gov (United States)

    Honda, Yuichiro; Sakamoto, Junya; Nakano, Jiro; Kataoka, Hideki; Sasabe, Ryo; Goto, Kyo; Tanaka, Miho; Origuchi, Tomoki; Yoshimura, Toshiro; Okita, Minoru

    2015-09-01

    In this study we investigated the molecular mechanism underlying muscle contracture in rats. The rats were divided into immobilization and control groups, and soleus muscles of the right and left sides were selected for analyses. The levels of CD11b and α-SMA protein, IL-1β, and TGF-β1 mRNA, and type I and III collagen protein and mRNA were significantly greater in the immobilization group than in the control group at all time-points. HIF-1α mRNA levels were significantly higher in the immobilization group at 4 weeks. Moreover, HIF-1α, α-SMA, and type I collagen levels were significantly higher at 4 weeks than at 1 and 2 weeks in the immobilization group. In the early stages of immobilization, upregulation of IL-1β/TGF-β1 via macrophages may promote fibroblast differentiation that could affect muscle contracture. The soleus muscle became hypoxic in the later stages of immobilization, suggesting that hypoxia influences the progression of muscle contracture. © 2014 Wiley Periodicals, Inc.

  1. High-molecular-weight adiponectin levels in healthy, community-dwelling, elderly Japanese volunteers: a 5-year prospective observational study.

    Science.gov (United States)

    Otsuka, Hiromasa; Yanai, Mitsuru; Kobayashi, Hiroki; Haketa, Akira; Hara, Motohiko; Sugama, Kaoru; Kato, Kimitoshi; Soma, Masayoshi

    2017-10-19

    Serum adiponectin levels are associated with frailty and cardiovascular diseases. Longitudinal changes in adiponectin levels might enhance our understanding of age-related conditions and diseases. This prospective observational study aimed to: (1) elucidate age-related changes in high-molecular-weight (HMW) adiponectin levels; and (2) identify variables predictive of elevated HMW adiponectin levels and the association with well-known adiponectin single-nucleotide polymorphisms (SNPs) in healthy, elderly Japanese participants. Healthy elderly volunteers (n = 196; 55 men and 141 women; median age 72.0 years; range 69.0-75.0 years) underwent anthropometric and physical function measurements, as well as laboratory tests at baseline and the 5-year follow-up. HMW adiponectin levels were significantly higher in women than in men (8.4, 5.3-11.9 vs. 5.7, 3.1-9.0 μg/mL; p density lipoprotein cholesterol levels and body weight were independent predictors of HMW adiponectin levels. The rate of change in HMW adiponectin levels was inversely correlated with the rates of change in body weight, body mass index, and knee leg extension strengths, and positively correlated with rates of change in high-density lipoprotein cholesterol and one-leg standing time. There were no significant differences in HMW adiponectin levels among SNPs. Decreasing HMW adiponectin levels might lead to an increased risk of cardiovascular diseases in elderly women. HMW adiponectin levels significantly decreased over a 5-year period in community-dwelling elderly Japanese women.

  2. Pressure effects on martensitic transformation under quenching process in a molecular dynamics model of NiAl alloy

    International Nuclear Information System (INIS)

    Kazanc, S.; Ozgen, S.; Adiguzel, O.

    2003-01-01

    The solid-solid phase transitions in NiAl alloys occur by the temperature changes and application of a pressure on the system. Both types of transitions are called martensitic transformation and have displacive and thermoelastic characters. Pressure effects on thermoelastic transformation in Ni 62.5 Al 37.5 alloy model have been studied by means of molecular dynamics method proposed by Parrinello-Rahman. Interaction forces between atoms in the model system were calculated by Lennard-Jones potential energy function. Thermodynamics and structural analysis of the martensitic transformations under hydrostatic pressure during the quenching processes have been performed. The simulation runs have been carried out in different hydrostatic pressures changing from zero to 40.65 GPa during the quenching process of the model alloy. At the zero and nonzero pressures, the system with B2-type ordered structure undergoes the product phase with L1 0 -type ordered structure by Bain distortion in the first step of martensitic transformation under the quenching process. The increase in hydrostatic pressure causes decrease in the formation time of the product phase, and twin-like lattice distortion is observed in low temperature L1 0 phase

  3. Magnetocaloric effect and critical behaviour in Mn2-pyridazine-[Nb(CN)8] molecular compound under press.

    Science.gov (United States)

    Fitta, Magdalena; Bałanda, Maria; Pełka, Robert; Konieczny, Piotr; Pinkowicz, Dawid; Sieklucka, Barbara

    2013-12-11

    A comprehensive study of magnetocaloric effect (MCE) and critical behaviour in the ferrimagnetic Mn2–pyridazine–[Nb(CN)8] molecular magnet under hydrostatic pressure is reported. The pressure-induced structural changes provoke the strengthening of magnetic interaction between Mn and Nb centres. Consequently, an increase of critical temperature Tc is observed from 43 K for a sample at ambient pressure (A) to 52.5 K for a sample under a pressure of 1.19 GPa (AHP). The magnetocaloric effect was determined by the magnetization measurements. The application of a hydrostatic pressure of 1.19 GPa causes a decrease in the maximum value of magnetic entropy change ΔS, which for AHP is equal to 4.63 J mol−1 K−1 (7.73 J kg−1 K−1) at μ0ΔH = 5 T, while for A it is 5.36 J mol−1 K−1 (8.95 J kg−1 K−1) for the same magnetic field change. The temperature-dependent parameter n obtained for AHP, describing the field dependence of MCE, is consistent with other critical exponents determined from magnetization measurements. The critical exponents allow us to classify AHP to the 3D Heisenberg universality class, similar to the case of the non-pressurized sample.

  4. Buckling Behavior of Carbon Nanotubes Functionalized with Carbene under Physical Adsorption of Polymer Chains: a Molecular Dynamics Study

    Science.gov (United States)

    Ajori, S.; Haghighi, S.; Ansari, R.

    2017-12-01

    The buckling analysis of functionalized carbon nanotubes (CNTs) is of great importance for the better understanding of mechanical behavior of nanocomposites. The buckling behavior of carbene-functionalized CNTs (cfCNTs) under physical adsorption of polymer chains (cfCNTs/polymers) is studied in this paper by the classical molecular dynamics (MD) simulations. In this regard, to investigate the interactions between non-covalent polymer chains and cfCNTs, two different non-covalent functional groups, i.e. polycarbonate (PC) and polypropylene (PP), are selected. The findings are compared with those of pure CNTs under the physical adsorption of polymer chains (pCNTs/polymers). The obtained results show that at a given weight percentage of non-covalent functional groups, the gyration radius of cfCNTs/polymers is higher than that of pCNTs/polymers. Furthermore, an increase in the critical buckling force of cfCNTs/polymers is dependent on the type of non-covalent polymer chains. For cfCNTs/PC and cfCNTs/PP, the critical buckling force is respectively lower and higher than that of pCNTs/polymers for the similar weight percentage of non-covalent functional groups. In addition, it is found that the critical buckling strain of cfCNTs/polymers is smaller than that of pCNTs/polymers for the same weight percentage of non-covalent polymer chains.

  5. Comparison of cryoconite organic matter composition from Arctic and Antarctic glaciers at the molecular-level

    Science.gov (United States)

    Pautler, Brent G.; Dubnick, Ashley; Sharp, Martin J.; Simpson, André J.; Simpson, Myrna J.

    2013-03-01

    Glacier surfaces are reservoirs that contain organic and inorganic debris referred to as cryoconite. Solar heating of this material results in the formation of water-filled depressions that are colonized by a variety of microbes and are hypothesized to play a role in carbon cycling in glacier ecosystems. Recent studies on cryoconite deposits have focused on their contribution to carbon fluxes to determine whether they are a net source or sink for atmospheric CO2. To better understand carbon cycling in these unique ecosystems, the molecular constituents of cryoconite organic matter (COM) require further elucidation. COM samples from four glaciers were analyzed by targeted extraction of plant- and microbial-derived biomarkers in conjunction with non-targeted NMR experiments to determine the COM composition and potential sources. Several molecular proxies were applied to assess COM degradation and microbial activity using samples from Greenland, the Canadian Arctic, and Antarctica. COM from Canadian (John Evans glacier) and Greenlandic (Leverett glacier) locations was more chemically heterogeneous than that from the Antarctic likely due to inputs from higher plants, mosses and Sphagnum as suggested by the solvent-extractable alkyl lipids and sterols and the detection of lignin- and Sphagnum-derived phenols after cupric oxide chemolysis. Solid-state 13C nuclear magnetic resonance (NMR) experiments highlighted the bulk chemical functional groups of COM allowing for a general assessment of its degradation stage from the alkyl/O-alkyl proxy whereas solution-state 1H NMR highlighted both microbial and plant contributions to base-soluble extracts from these COM samples. The dominance of 1H NMR signals from microbial protein/peptides in base-soluble extracts of COM from Antarctica (Joyce glacier and Garwood glacier), phospholipid fatty acid (PLFA) biomarker detection and the absence of plant-derived biomarkers in both the solvent and cupric oxide extracts suggests that this

  6. Molecular design of new P3HT derivatives: Adjusting electronic energy levels for blends with PCBM

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Eliezer Fernando [UNESP – Univ Estadual Paulista, POSMAT – Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, Bauru, SP (Brazil); Lavarda, Francisco Carlos, E-mail: lavarda@fc.unesp.br [UNESP – Univ Estadual Paulista, POSMAT – Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, Bauru, SP (Brazil); Faculdade de Ciências, UNESP – Univ Estadual Paulista, Departamento de Física, Av. Eng. Luiz Edmundo Carrijo Coube, 14-01, 17033-360 Bauru, SP (Brazil)

    2014-12-15

    An intensive search is underway for new materials to make more efficient organic solar cells through improvements in thin film morphology, transport properties, and adjustments to the energy of frontier electronic levels. The use of chemical modifications capable of modifying the electronic properties of materials already known is an interesting approach, as it can, in principle, provide a more adequate adjustment of the frontier electronic levels while preserving properties such as solubility. Based on this idea, we performed a theoretical study of poly(3-hexylthiophene) (P3HT) and 13 new derivatives obtained by substitution with electron acceptor and donor groups, in order to understand how the energy levels of the frontier orbitals are modified. The results show that it is possible to deduce the modification of the electronic levels in accordance with the substituent's acceptor/donor character. We also evaluated how the substituents influence the open circuit voltage and the exciton binding energy. - Highlights: • Prediction of P3HT derivatives properties for bulk-heterojunction solar cells. • Correlating substituent properties with electronic levels of P3HT derivatives. • Fluorinated P3HT improves open circuit voltage and stability.

  7. On reproduction in red algae: further research needed at the molecular level.

    Science.gov (United States)

    García-Jiménez, Pilar; Robaina, Rafael R

    2015-01-01

    Multicellular red algae (Rhodophyta) have some of the most complex life cycles known in living organisms. Economically valuable seaweeds, such as phycocolloid producers, have a triphasic (gametophyte, carposporophyte, and tetrasporophyte) life cycle, not to mention the intricate alternation of generations in the edible "sushi-alga" nori. It is a well-known fact that reproductive processes are controlled by one or more abiotic factor(s), including day length, light quality, temperature, and nutrients. Likewise, endogenous chemical factors such as plant growth regulators have been reported to affect reproductive events in some red seaweeds. Still, in the genomic era and given the high throughput techniques at our disposal, our knowledge about the endogenous molecular machinery lags far behind that of higher plants. Any potential effective control of the reproductive process will entail revisiting most of these results and facts to answer basic biological questions as yet unresolved. Recent results have shed light on the involvement of several genes in red alga reproductive events. In addition, a working species characterized by a simple filamentous architecture, easy cultivation, and accessible genomes may also facilitate our task.

  8. Canine spontaneous head and neck squamous cell carcinomas represent their human counterparts at the molecular level.

    Directory of Open Access Journals (Sweden)

    Deli Liu

    2015-06-01

    Full Text Available Spontaneous canine head and neck squamous cell carcinoma (HNSCC represents an excellent model of human HNSCC but is greatly understudied. To better understand and utilize this valuable resource, we performed a pilot study that represents its first genome-wide characterization by investigating 12 canine HNSCC cases, of which 9 are oral, via high density array comparative genomic hybridization and RNA-seq. The analyses reveal that these canine cancers recapitulate many molecular features of human HNSCC. These include analogous genomic copy number abnormality landscapes and sequence mutation patterns, recurrent alteration of known HNSCC genes and pathways (e.g., cell cycle, PI3K/AKT signaling, and comparably extensive heterogeneity. Amplification or overexpression of protein kinase genes, matrix metalloproteinase genes, and epithelial-mesenchymal transition genes TWIST1 and SNAI1 are also prominent in these canine tumors. This pilot study, along with a rapidly growing body of literature on canine cancer, reemphasizes the potential value of spontaneous canine cancers in HNSCC basic and translational research.

  9. Molecular-level origins of biomass recalcitrance: decrystallization free energies for four common cellulose polymorphs.

    Science.gov (United States)

    Beckham, Gregg T; Matthews, James F; Peters, Baron; Bomble, Yannick J; Himmel, Michael E; Crowley, Michael F

    2011-04-14

    Cellulose is a crystalline polymer of β1,4-D-glucose that is difficult to deconstruct to sugars by enzymes. The recalcitrance of cellulose microfibrils is a function of both the shape of cellulose microfibrils and the intrinsic work required to decrystallize individual chains, the latter of which is calculated here from the surfaces of four crystalline cellulose polymorphs: cellulose Iβ, cellulose Iα, cellulose II, and cellulose III(I). For edge chains, the order of decrystallization work is as follows (from highest to lowest): Iβ, Iα, ΙΙΙ(Ι), and II. For cellulose Iβ, we compare chains from three different locations on the surface and find that an increasing number of intralayer hydrogen bonds (from 0 to 2) increases the intrinsic decrystallization work. From these results, we propose a microkinetic model for the deconstruction of cellulose (and chitin) by processive enzymes, which when taken with a previous study [Horn et al. Proc. Natl. Acad. Sci. U.S.A. 2006, 103, 18089] identifies the thermodynamic and kinetic attributes of enzyme and substrate engineering for enhanced cellulose (or chitin) conversion. Overall, this study provides new insights into the molecular interactions that form the structural basis of cellulose, which is the primary building block of plant cell walls, and highlights the need for experimentally determining microfibril shape at the nanometer length scale when comparing conversion rates of cellulose polymorphs by enzymes.

  10. The HTLV-I Tax oncoprotein: hyper-tasking at the molecular level.

    Science.gov (United States)

    Wycuff, Diane R; Marriott, Susan J

    2005-01-01

    HTLV-I is a complex retrovirus that encodes a transcriptional activator, Tax, which regulates expression of the viral promoter. Tax has been shown to be both necessary and sufficient to effect immortalization and transformation of cells in culture and tumorigenesis in animal models. Tax exerts its influence through protein-protein interactions with a variety of molecular targets, including transcription factors and cofactors, histone modifying enzymes and post-translational modifying enzymes. Through these interactions, Tax disrupts cellular regulatory cascades and checkpoints designed to control a variety of systems. The result is untimely activation or repression of gene expression, inappropriate protein modifications, incorrect cell cycling, loss of adequate DNA repair capacity, and potential release of the cell from tumor suppression. Whereas for the virus these functions of Tax provide a means for successful completion of its life cycle, for the cell, they result at best in anarchy, and at worst in death of both the cell and the organism of which that cell is a part.

  11. On reproduction in red algae: further research needed at the molecular level

    Directory of Open Access Journals (Sweden)

    Pilar eGarcía-Jiménez

    2015-02-01

    Full Text Available Multicellular red algae (Rhodophyta have some of the most complex life cycles known in living organisms. Economically valuable seaweeds, such as phycocolloid producers, have a triphasic (gametophyte, carposporophyte and tetrasporophyte life cycle, not to mention the intricate alternation of generations in the edible sushi-alga nori. It is a well-known fact that reproductive processes are controlled by one or more abiotic factor(s, including day length, light quality, temperature and nutrients. Likewise, endogenous chemical factors such as plant growth regulators have been reported to affect reproductive events in some red seaweeds. Still, in the genomic era and given the high throughput techniques at our disposal, our knowledge about the endogenous molecular machinery lags far behind that of higher plants. Any potential effective control of the reproductive process will entail revisiting most of these results and facts to answer basic biological questions as yet unresolved. Recent results have shed light on the involvement of several genes in red alga reproductive events. In addition, a working species characterized by a simple filamentous architecture, easy cultivation and accessible genomes may also facilitate our task.

  12. On reproduction in red algae: further research needed at the molecular level

    Science.gov (United States)

    García-Jiménez, Pilar; Robaina, Rafael R.

    2015-01-01

    Multicellular red algae (Rhodophyta) have some of the most complex life cycles known in living organisms. Economically valuable seaweeds, such as phycocolloid producers, have a triphasic (gametophyte, carposporophyte, and tetrasporophyte) life cycle, not to mention the intricate alternation of generations in the edible “sushi-alga” nori. It is a well-known fact that reproductive processes are controlled by one or more abiotic factor(s), including day length, light quality, temperature, and nutrients. Likewise, endogenous chemical factors such as plant growth regulators have been reported to affect reproductive events in some red seaweeds. Still, in the genomic era and given the high throughput techniques at our disposal, our knowledge about the endogenous molecular machinery lags far behind that of higher plants. Any potential effective control of the reproductive process will entail revisiting most of these results and facts to answer basic biological questions as yet unresolved. Recent results have shed light on the involvement of several genes in red alga reproductive events. In addition, a working species characterized by a simple filamentous architecture, easy cultivation, and accessible genomes may also facilitate our task. PMID:25755663

  13. Towards a molecular level understanding of the sulfanilamide-soil organic matter-interaction.

    Science.gov (United States)

    Ahmed, Ashour A; Thiele-Bruhn, Sören; Leinweber, Peter; Kühn, Oliver

    2016-07-15

    Sorption experiments of sulfanilamide (SAA) on well-characterized samples of soil size-fractions were combined with the modeling of SAA-soil-interaction via quantum chemical calculations. Freundlich unit capacities were determined in batch experiments and it was found that they increase with the soil organic matter (SOM) content according to the order fine silt > medium silt > clay > whole soil > coarse silt > sand. The calculated binding energies for mass-spectrometrically quantified sorption sites followed the order ionic species > peptides > carbohydrates > phenols and lignin monomers > lignin dimers > heterocyclic compounds > fatty acids > sterols > aromatic compounds > lipids, alkanes, and alkenes. SAA forms H-bonds through its polar centers with the polar SOM sorption sites. In contrast dispersion and π-π-interactions predominate the interaction of the SAA aromatic ring with the non-polar moieties of SOM. Moreover, the dipole moment, partial atomic charges, and molecular volume of the SOM sorption sites are the main physical properties controlling the SAA-SOM-interaction. Further, reasonable estimates of the Freundlich unit capacities from the calculated binding energies have been established. Consequently, we suggest using this approach in forthcoming studies to disclose the interactions of a wide range of organic pollutants with SOM. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Threat to food security under current levels of ground level ozone: A case study for Indian cultivars of rice

    Science.gov (United States)

    Rai, Richa; Agrawal, Madhoolika; Agrawal, S. B.

    2010-11-01

    A higher ozone concentration in rural agricultural region poses threat to food production in developing countries. The present study was conducted to evaluate the growth, biomass accumulation and allocation pattern, quantitative and qualitative characteristics of grains for two tropical rice cultivars ( Oryza sativa L. cv NDR 97 and Saurabh 950) at ambient O 3 concentrations at a rural site in the Indo Gangetic plains of India. Percent inhibition in number of leaves was higher for NDR 97, but in leaf area for Saurabh 950 grown in non filtered chambers (NFCs) compared to filtered chambers (FCs). Higher inhibition in root biomass was recorded in Saurabh 950 and in leaf and standing dead biomass for NDR 97. During vegetative phase, relative growth rate showed more percent inhibition in Saurabh 950, but at reproductive phase in NDR 97. Net assimilation rate showed higher values for Saurabh 950 than NDR 97 in NFCs but percent inhibition in leaf area ratio was higher for former than latter cultivar in NFCs. The ozone resistance was higher in NDR 97 during vegetative phase, but in Saurabh 950 at reproductive phase. Number of grains was higher in NDR 97 than Saurabh 950, but test weight and weight of grains m -2 showed reverse trends. Concentrations of starch, protein, P, N, Ca, Mg and K decreased, while reducing and total soluble sugar increased in grains of both the cultivars in NFCs compared to FCs. The study concluded that under ambient condition of O 3 exposure, the two cultivars responded differently. Saurabh 950 favoured biomass translocation priority towards ear in reproductive phase and hence showed higher resistivity due to maintenance of higher test weight. NDR 97, however, showed better growth during vegetative period, but could not allocate efficiently to developing ears, hence higher number of unfilled grains in NFCs led lower test weight.

  15. Improvement of blood inflammatory marker levels in patients with hypothyroidism under levothyroxine treatment.

    Science.gov (United States)

    Marchiori, Roseane C; Pereira, Luiz A F; Naujorks, Alexandre A; Rovaris, Diego L; Meinerz, Daiane F; Duarte, Marta M M F; Rocha, João B T

    2015-06-23

    There are several specific inflammatory and oxidative correlates among patients with hypothyroidism, but most studies are cross-sectional and do not evaluate the change in parameters during the treatment. The aim of this study was to investigate the effect of levothyroxine replacement therapy on biomarkers of oxidative stress (OS) and systemic inflammation in patients with hypothyroidism. In this prospective open-label study, 17 patients with recently diagnosed primary hypothyroidism due to Hashimoto's thyroiditis who were not taking levothyroxine were included. The following parameters were measured before and at 6 and 12 months of levothyroxine treatment with an average dose of 1.5 to 1.7 μg/kg/day: thyroid-stimulating hormone (TSH), free thyroxine (FT4), high-sensitivity C-reactive protein (hs-CRP), interleukin 1 (IL-1), IL-6, IL-10, interferon gamma (INF-γ), tumor necrosis factor alpha (TNF-α), thiobarbituric acid-reactive substances (TBARS), activity of aminolevulinic acid dehydratase (δ-ALA-D), nonprotein and total thiol (NP-SH and T-SH) groups, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG). Generalized estimating equation (GEE) modeling was used to analyze the effects of LRT (at pre-treatment, 6 months and 12 months) on those variables. The hypothyroidism status (i.e., overt or subclinical hypothyroidism) was included as a confounder in all analyses. An additional GEE post hoc analysis was made to compare time points. There was a significant decrease in TSH over time (P < 0.0001), (initial levels were on average 32.4 μIU/mL and 10.5 μIU/mL at 12 months). There was a significant increase in FT4 (P < 0.0001) (initial levels were on average 0,8 ng/dL and 2.7 ng/dL at 12 months). There were significant changes in interleukin levels over time, with a significant increase in IL-10 (P < 0.0001) and significant decreases in IL-1 (P < 0.0001), IL-6 (P

  16. Surface Functionalization of g-C 3 N 4 : Molecular-Level Design of Noble-Metal-Free Hydrogen Evolution Photocatalysts

    KAUST Repository

    Chen, Yin

    2015-06-12

    A stable noble-metal-free hydrogen evolution photocatalyst based on graphite carbon nitride (g-C3N4) was developed by a molecular-level design strategy. Surface functionalization was successfully conducted to introduce a single nickel active site onto the surface of the semiconducting g-C3N4. This catalyst family (with less than 0.1 wt% of Ni) has been found to produce hydrogen with a rate near to the value obtained by using 3 wt% platinum as co-catalyst. This new catalyst also exhibits very good stability under hydrogen evolution conditions, without any evidence of deactivation after 24h. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Molecular profiling of short-term and long-term surviving patients identifies CD34 mRNA level as prognostic for glioblastoma survival

    DEFF Research Database (Denmark)

    Michaelsen, Signe Regner; Urup, Thomas; Olsen, Lars Rønn

    2018-01-01

    Despite extensive treatment, overall survival (OS) for glioblastoma (GBM) remains poor. A small proportion of patients present long survival over 3 years, but the underlying molecular background separating these long-term survivors (LTS) from short-term survivors (STS) are insufficiently understood......-type. RNA expression levels in diagnostic tumor specimen for 792 genes were analyzed by NanoString technology. While no differences were found with regard to GBM subtype between LTS versus STS, comparative analysis of individual genes identified 14 significantly differently expressed candidate genes...... analyses in an independent dataset from the AVAglio study confirmed CD34 as significant in comparative analysis between STS and LTS patients and as an independent prognostic factor. Analysis of this dataset further supported CD34 expression to be associated with improved bevacizumab efficacy, while CD34...

  18. Secondary electron emission of thin carbon foils under the impact of hydrogen atoms, ions and molecular ions, under energies within the MeV range

    International Nuclear Information System (INIS)

    Vidovic, Z.

    1997-06-01

    This work focuses on the study of the emission statistics of secondary electrons from thin carbon foils bombarded with H 0 , H 2 + and H 3 + projectiles in the 0.25-2.2 MeV energy range. The phenomenon of secondary electron emission from solids under the impact of swift ions is mainly due to inelastic interactions with target electrons. The phenomenological and theoretical descriptions, as well as a summary of the main theoretical models are the subject of the first chapter. The experimental set-up used to measure event by event the electron emission of the two faces of a thin carbon foil traversed by an energetic projectile is described in the chapter two. In this chapter are also presented the method and algorithms used to process experimental spectra in order to obtain the statistical distribution of the emitted electrons. Chapter three presents the measurements of secondary electron emission induced by H atoms passing through thin carbon foils. The secondary electron yields are studied in correlation with the emergent projectile charge state. We show the peculiar role of the projectile electron, whether it remains or not bound to the incident proton. The fourth chapter is dedicated to the secondary electron emission induced by H 2 + and H 3 + polyatomic ions. The results are interpreted in terms of collective effects in the interactions of these ions with solids. The role of the proximity of the protons, molecular ion fragments, upon the amplitude of these collective effects is evidenced from the study of the statistics of forward emission. These experiences allowed us to shed light on various aspects of atom and polyatomic ion inter-actions with solid surfaces. (author)

  19. Increased vulnerability of Zostera noltii to stress caused by low light and elevated ammonium levels under phosphate deficiency

    NARCIS (Netherlands)

    Brun, F.G.; Olivé, I.; Malta, E.J.; Vergara, J.J.; Hernández, I.; Pérez-Lloréns, J.J.

    2008-01-01

    The effects of light and ammonium levels on net production, fluorescence parameters and non-structural carbohydrates of the seagrass Zostera noltii under different phosphate conditions were studied. A fully factorial design was used with light (low/high levels), ammonium supply and phosphate

  20. Biodiversity at the molecular level: the domains, kingdoms and phyla of life.

    Science.gov (United States)

    Embley, T M; Hirt, R P; Williams, D M

    1994-07-29

    The results of comparative sequence analysis, mainly of small subunit (SSU) ribosomal (r)RNA sequences, have suggested that all of cellular life can be placed in one of three domains: the Archaea, Bacteria or Eucarya. There is some evidence that the Archaea may not be a monophyletic assemblage, but as yet this issue has not been resolved. Most of the lineages, and all of the deepest ones, in the tree based upon SSU rRNA sequences, are microbial. Traditional ideas of classification such as Whittaker's five kingdom scheme do not adequately describe life's diversity as revealed by sequence comparisons. There are many microbial groups that demonstrate much greater amounts of SSU rRNA sequence divergence than do members of the classical kingdoms, Animalia, Plantae and Fungi. The old microbial kingdoms Monera and Protista are clearly paraphyletic but as yet there is no consensus as to how they should be reorganized in taxonomic terms. New data from environmental analysis suggests that much of the microbial world is unknown. Every environment which has been analysed by molecular methods has revealed many previously unrecorded lineages. Some of these show great divergence from the sequences of cultured microorganisms suggesting that fundamentally new microbial groups remain to be isolated. The relationships of some of these new lineages may be expected to affect how the tree of life is organized into higher taxa, and to also influence which features will be recognized as synapomorphies. There is currently no objective measure whereby microbial diversity can be quantified and compared to the figures which are widely quoted for arthropods and other Metazoa.

  1. Towards a molecular level understanding of the sulfanilamide-soil organic matter-interaction

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Ashour A., E-mail: ashour.ahmed@uni-rostock.de [University of Rostock, Institute of Physics, Albert-Einstein-Str. 23-24, D-18059 Rostock (Germany); Steinbeis GmbH & Co. KG für Technologietransfer, 70174 Stuttgart (Germany); University of Cairo, Faculty of Science, Department of Chemistry, 12613 Giza (Egypt); Thiele-Bruhn, Sören, E-mail: thiele@uni-trier.de [University of Trier, Soil Science, D-54286 Trier (Germany); Leinweber, Peter, E-mail: peter.leinweber@uni-rostock.de [Steinbeis GmbH & Co. KG für Technologietransfer, 70174 Stuttgart (Germany); University of Rostock, Soil Science, D-18051 Rostock (Germany); Kühn, Oliver, E-mail: oliver.kuehn@uni-rostock.de [University of Rostock, Institute of Physics, Albert-Einstein-Str. 23-24, D-18059 Rostock (Germany)

    2016-07-15

    Sorption experiments of sulfanilamide (SAA) on well-characterized samples of soil size-fractions were combined with the modeling of SAA-soil-interaction via quantum chemical calculations. Freundlich unit capacities were determined in batch experiments and it was found that they increase with the soil organic matter (SOM) content according to the order fine silt > medium silt > clay > whole soil > coarse silt > sand. The calculated binding energies for mass-spectrometrically quantified sorption sites followed the order ionic species > peptides > carbohydrates > phenols and lignin monomers > lignin dimers > heterocyclic compounds > fatty acids > sterols > aromatic compounds > lipids, alkanes, and alkenes. SAA forms H-bonds through its polar centers with the polar SOM sorption sites. In contrast dispersion and π-π-interactions predominate the interaction of the SAA aromatic ring with the non-polar moieties of SOM. Moreover, the dipole moment, partial atomic charges, and molecular volume of the SOM sorption sites are the main physical properties controlling the SAA-SOM-interaction. Further, reasonable estimates of the Freundlich unit capacities from the calculated binding energies have been established. Consequently, we suggest using this approach in forthcoming studies to disclose the interactions of a wide range of organic pollutants with SOM. - Highlights: • Experiment and theory showed that SAA obeys a site-specific sorption on soil surfaces. • SAA-SOM-interaction increases by increasing polarity of SOM sorption site. • H-bonds, dispersion, and π-π-interactions were observed for SAA-SOM-interaction. • Dipole moment and atomic charges of SOM sorption sites control SAA-SOM-interaction. • The Freundlich unit capacities were estimated from the calculated binding energies. • The current SOM model is flexible to describe interactions of SOM with other pollutants.

  2. Fragile X and autism: Intertwined at the molecular level leading to targeted treatments

    Directory of Open Access Journals (Sweden)

    Hagerman Randi

    2010-09-01

    Full Text Available Abstract Fragile X syndrome (FXS is caused by an expanded CGG repeat (> 200 repeats in the 5' untranslated portion of the fragile mental retardation 1 gene (FMR1, leading to deficiency or absence of the FMR1 protein (FMRP. FMRP is an RNA carrier protein that controls the translation of several other genes that regulate synaptic development and plasticity. Autism occurs in approximately 30% of FXS cases, and pervasive developmental disorder, not otherwise specified (PDD-NOS occurs in an additional 30% of cases. Premutation repeat expansions (55 to 200 CGG repeats may also give rise to autism spectrum disorders (ASD, including both autism and PDD-NOS, through a different molecular mechanism that involves a direct toxic effect of the expanded CGG repeat FMR1 mRNA. RNA toxicity can also lead to aging effects including tremor, ataxia and cognitive decline, termed fragile X-associated tremor ataxia syndrome (FXTAS, in premutation carriers in late life. In studies of mice bearing premutation expansions, there is evidence of early postnatal neuronal cell toxicity, presenting as reduced cell longevity, decreased dendritic arborization and altered synaptic morphology. There is also evidence of mitochondrial dysfunction in premutation carriers. Many of the problems with cellular dysregulation in both premutation and full mutation neurons also parallel the cellular abnormalities that have been documented in autism without fragile X mutations. Research regarding dysregulation of neurotransmitter systems in FXS, including the metabotropic glutamate receptor (mGluR1/5 pathway and γ aminobutyric acid (GABAA pathways, have led to new targeted treatments for FXS. Preliminary evidence suggests that these new targeted treatments will also be beneficial in non-fragile X forms of autism.

  3. Sea level rise projections for Northern Europe under RCP8.5

    NARCIS (Netherlands)

    Grinsted, A.; Jevrejeva, S.; Riva, R.E.M.; Dahl-Jensen, D.

    2015-01-01

    Sea level rise poses a significant threat to coastal communities, infrastructure, and ecosystems. Sea level rise is not uniform globally but is affected by a range of regional factors. In this study, we calculate regional projections of 21st century sea level rise in northern Europe, focusing on the

  4. Low striatal glutamate levels underlie cognitive decline in the elderly: evidence from in vivo molecular spectroscopy.

    Science.gov (United States)

    Zahr, Natalie M; Mayer, Dirk; Pfefferbaum, Adolf; Sullivan, Edith V

    2008-10-01

    Glutamate (Glu), the principal excitatory neurotransmitter of prefrontal cortical efferents, potentially mediates higher order cognitive processes, and its altered availability may underlie mechanisms of age-related decline in frontally based functions. Although animal studies support a role for Glu in age-related cognitive deterioration, human studies, which require magnetic resonance spectroscopy for in vivo measurement of this neurotransmitter, have been impeded because of the similarity of Glu's spectroscopic signature to those of neighboring spectral brain metabolites. Here, we used a spectroscopic protocol, optimized for Glu detection, to examine the effect of age in 3 brain regions targeted by cortical efferents--the striatum, cerebellum, and pons--and to test whether performance on frontally based cognitive tests would be predicted by regional Glu levels. Healthy elderly men and women had lower Glu in the striatum but not pons or cerebellum than young adults. In the combined age groups, levels of striatal Glu (but no other proton metabolite also measured) correlated selectively with performance on cognitive tests showing age-related decline. The selective relations between performance and striatal Glu provide initial and novel, human in vivo support for age-related modification of Glu levels as contributing to cognitive decline in normal aging.

  5. Intrinsic bacterial biodegradation of petroleum contamination demonstrated in situ using natural abundance, molecular-level 14C analysis

    International Nuclear Information System (INIS)

    Slater, G.F.; Nelson, R.K.; Kile, B.M.; Reddy, C.M.

    2006-01-01

    Natural abundance, molecular-level C 14 analysis was combined with comprehensive gas chromatography (GC x GC) to investigate, in situ, the role of intrinsic biodegradation in the loss of petroleum hydrocarbons from the rocky, inter-tidal zone impacted by the Bouchard 120 oil spill. GC x GC analysis indicated accelerated losses of n-alkane components of the residual petroleum hydrocarbons between day 40 and day 50 after the spill. 14 C analysis of bacterial phospholipid fatty acids (PLFA) from the impacted zone on day 44 showed that the polyunsaturated fatty acids attributed to the photoautotrophic component of the microbial community had the same ( 14 C as the local dissolved inorganic carbon (DIG), indicating that this DIG was their carbon source. In contrast there was significant (C depletion in the saturated and mono-unsaturated PLFA indicating incorporation of petroleum carbon. This correlation between the observed accelerated n-alkane losses and microbial incorporation of (C-depleted carbon directly demonstrated, in situ, that intrinsic biodegradation was affecting the petroleum. Since the majority of organic contaminants originate from petroleum feed-stocks, in situ molecular-level 14 C analysis of microbial PLFA can provide insights into the occurrence and pathways of biodegradation of a wide range of organic contaminants. (Author)

  6. An Investigation of Bacterial Protein Interactions as a Primary Research Project in a Sophomore-Level Molecular Biology Course

    Directory of Open Access Journals (Sweden)

    Jean A. Cardinale

    2011-09-01

    Full Text Available Longer term research activities that may be incorporated in undergraduate courses are a powerful tool for promoting student interest and learning, developing cognitive process skills, and allowing undergraduates to experience real research activities in which they may not otherwise have the opportunity to participate. The challenge to doing so in lower-level courses is that students may have not fully grasped the scientific concepts needed to undertake such research endeavors, and that they may be discouraged if activities are perceived to be too challenging. The paper describes how a bacterial protein:protein interaction detection system was adapted and incorporated into the laboratory component of a sophomore-level Molecular Cell Biology course. The project was designed to address multiple learning objectives connecting course content to the laboratory activities, as well as teach basic molecular biology laboratory skills and procedures in the context of a primary research activity. Pre- and posttesting and student surveys both suggest that the laboratory curriculum resulted in significant learning gains, as well as being well received and valued by the students.

  7. An investigation of bacterial protein interactions as a primary research project in a sophomore-level molecular biology course.

    Science.gov (United States)

    Cardinale, Jean A

    2011-01-01

    Longer term research activities that may be incorporated in undergraduate courses are a powerful tool for promoting student interest and learning, developing cognitive process skills, and allowing undergraduates to experience real research activities in which they may not otherwise have the opportunity to participate. The challenge to doing so in lower-level courses is that students may have not fully grasped the scientific concepts needed to undertake such research endeavors, and that they may be discouraged if activities are perceived to be too challenging. The paper describes how a bacterial protein:protein interaction detection system was adapted and incorporated into the laboratory component of a sophomore-level Molecular Cell Biology course. The project was designed to address multiple learning objectives connecting course content to the laboratory activities, as well as teach basic molecular biology laboratory skills and procedures in the context of a primary research activity. Pre- and posttesting and student surveys both suggest that the laboratory curriculum resulted in significant learning gains, as well as being well received and valued by the students.

  8. Identifying Enclosed Chemical Reaction and Dynamics at the Molecular Level Using Shell-Isolated Miniaturized Plasmonic Liquid Marble.

    Science.gov (United States)

    Han, Xuemei; Lee, Hiang Kwee; Lee, Yih Hong; Hao, Wei; Liu, Yejing; Phang, In Yee; Li, Shuzhou; Ling, Xing Yi

    2016-04-21

    Current microscale tracking of chemical kinetics is limited to destructive ex situ methods. Here we utilize Ag nanocube-based plasmonic liquid marble (PLM) microreactor for in situ molecular-level identification of reaction dynamics. We exploit the ultrasensitive surface-enhanced Raman scattering (SERS) capability imparted by the plasmonic shell to unravel the mechanism and kinetics of aryl-diazonium surface grafting reaction in situ, using just a 2-μL reaction droplet. This reaction is a robust approach to generate covalently functionalized metallic surfaces, yet its kinetics remain unknown to date. Experiments and simulations jointly uncover a two-step sequential grafting process. An initial Langmuir chemisorption of sulfonicbenzene diazonium (dSB) salt onto Ag surfaces forms an intermediate sulfonicbenzene monolayer (Ag-SB), followed by subsequent autocatalytic multilayer growth of Ag-SB3. Kinetic rate constants reveal 19-fold faster chemisorption than multilayer growth. Our ability to precisely decipher molecular-level reaction dynamics creates opportunities to develop more efficient processes in synthetic chemistry and nanotechnology.

  9. Operational nanometric gas counters for nuclear risk assessment at the bio-molecular level

    Energy Technology Data Exchange (ETDEWEB)

    Baek, W. Y.; Grosswendt, B. [Physikalisch-Technische Bundesanstalt, Bundesallee, Braunschweig, (Germany); Watt, D. E. [University of Andrews, Fife, (United Kingdom); Breskin, A. [Weizmann Institute of Science, Rehovot (Israel); Colautti, P. [INFN Laboratori Nazionali di Legarno, Legarno (Italy)

    1999-07-01

    The practical implementation of the system for protection of persons against exposure to ionizing radiation requires that appropriate radiation detectors be designed to produce an output signal which can be related to the risk of deleterious biological effect. At present, conventional dosimeters are used to assess the risk either by measurement of macroscopic quantities such as energy imparted, modified by appropriately evaluated weighting factors, or by microdosimeters which can measure simultaneously the dose and a quality factor obtained from the stochastic distribution of dose, e.g. the lineal energy of microdosimetry. Both types of dosimeter now have recognised limitations which inhibit their accuracy for damage assessment. This is because in practice their radiation response functions could not take account of advances in our understanding of the radiobiological damage mechanisms which involve 'target' sizes of sub-micron dimensions, less than 30 nm, and probably as small as molecular dimensions of 2 nm e.g. a segment of the DNA. If radiation detectors can be designed to simulate the response of relevant biological material by allowing for the dimensions and multiplicity of the radiosensitive target sizes, then there are good prospects of achieving significant improvements in dosimetry instrumentation which, in principle, could lead to direct measurement of risk in unknown radiation fields without the need for arbitrary modifying factors or knowledge of the radiation type. In this context of the foregoing, a prototype of a nanodosimetric counter has been built and used to measure the ionization cluster size distributions for energetic {alpha}-particles in tissue equivalent gases with a spatial resolution of 1 nm. The total and double differential electron scattering cross-sections of the components of the tissue equivalent gases have been measured absolutely for electron energies up to 5 keV and for scattering angles from 30 deg to 120 deg by

  10. Molecular design of photovoltaic materials for polymer solar cells: toward suitable electronic energy levels and broad absorption.

    Science.gov (United States)

    Li, Yongfang

    2012-05-15

    Bulk heterojunction (BHJ) polymer solar cells (PSCs) sandwich a blend layer of conjugated polymer donor and fullerene derivative acceptor between a transparent ITO positive electrode and a low work function metal negative electrode. In comparison with traditional inorganic semiconductor solar cells, PSCs offer a simpler device structure, easier fabrication, lower cost, and lighter weight, and these structures can be fabricated into flexible devices. But currently the power conversion efficiency (PCE) of the PSCs is not sufficient for future commercialization. The polymer donors and fullerene derivative acceptors are the key photovoltaic materials that will need to be optimized for high-performance PSCs. In this Account, I discuss the basic requirements and scientific issues in the molecular design of high efficiency photovoltaic molecules. I also summarize recent progress in electronic energy level engineering and absorption spectral broadening of the donor and acceptor photovoltaic materials by my research group and others. For high-efficiency conjugated polymer donors, key requirements are a narrower energy bandgap (E(g)) and broad absorption, relatively lower-lying HOMO (the highest occupied molecular orbital) level, and higher hole mobility. There are three strategies to meet these requirements: D-A copolymerization for narrower E(g) and lower-lying HOMO, substitution with electron-withdrawing groups for lower-lying HOMO, and two-dimensional conjugation for broad absorption and higher hole mobility. Moreover, better main chain planarity and less side chain steric hindrance could strengthen π-π stacking and increase hole mobility. Furthermore, the molecular weight of the polymers also influences their photovoltaic performance. To produce high efficiency photovoltaic polymers, researchers should attempt to increase molecular weight while maintaining solubility. High-efficiency D-A copolymers have been obtained by using benzodithiophene (BDT), dithienosilole

  11. Predicting the impact of tsunami in California under rising sea level

    Science.gov (United States)

    Dura, T.; Garner, A. J.; Weiss, R.; Kopp, R. E.; Horton, B.

    2017-12-01

    The flood hazard for the California coast depends not only on the magnitude, location, and rupture length of Alaska-Aleutian subduction zone earthquakes and their resultant tsunamis, but also on rising sea levels, which combine with tsunamis to produce overall flood levels. The magnitude of future sea-level rise remains uncertain even on the decadal scale, with future sea-level projections becoming even more uncertain at timeframes of a century or more. Earthquake statistics indicate that timeframes of ten thousand to one hundred thousand years are needed to capture rare, very large earthquakes. Because of the different timescales between reliable sea-level projections and earthquake distributions, simply combining the different probabilities in the context of a tsunami hazard assessment may be flawed. Here, we considered 15 earthquakes between Mw 8 to Mw 9.4 bound by -171oW and -140oW of the Alaska-Aleutian subduction zone. We employed 24 realizations at each magnitude with random epicenter locations and different fault length-to-width ratios, and simulated the tsunami evolution from these 360 earthquakes at each decade from the years 2000 to 2200. These simulations were then carried out for different sea-level-rise projections to analyze the future flood hazard for California. Looking at the flood levels at tide gauges, we found that the flood level simulated at, for example, the year 2100 (including respective sea-level change) is different from the flood level calculated by adding the flood for the year 2000 to the sea-level change prediction for the year 2100. This is consistent for all sea-level rise scenarios, and this difference in flood levels range between 5% and 12% for the larger half of the given magnitude interval. Focusing on flood levels at the tide gauge in the Port of Los Angeles, the most probable flood level (including all earthquake magnitudes) in the year 2000 was 5 cm. Depending on the sea-level predictions, in the year 2050 the most probable

  12. Molecular epidemiology and strain-specific characteristics of Streptococcus agalactiae at the herd and cow level.

    Science.gov (United States)

    Mahmmod, Y S; Klaas, I C; Katholm, J; Lutton, M; Zadoks, R N

    2015-10-01

    Host-adaptation of Streptococcus agalactiae subpopulations has been described whereby strains that are commonly associated with asymptomatic carriage or disease in people differ phenotypically and genotypically from those causing mastitis in dairy cattle. Based on multilocus sequence typing (MLST), the most common strains in dairy herds in Denmark belong to sequence types (ST) that are also frequently found in people. The aim of this study was to describe epidemiological and diagnostic characteristics of such strains in relation to bovine mastitis. Among 1,199 cattle from 6 herds, cow-level prevalence of S. agalactiae was estimated to be 27.4% based on PCR and 7.8% based on bacteriological culture. Quarter-level prevalence was estimated at 2.8% based on bacteriological culture. Per herd, between 2 and 26 isolates were characterized by pulsed-field gel electrophoresis (PFGE) and MLST. Within each herd, a single PFGE type and ST predominated, consistent with a contagious mode of transmission or point source infection within herds. Evidence of within-herd evolution of S. agalactiae was detected with both typing methods, although ST belonged to a single clonal complex (CC) per herd. Detection of CC23 (3 herds) was associated with significantly lower approximate count (colony-forming units) at the quarter level and significantly lower cycle threshold value at the cow level than detection of CC1 (2 herds) or CC19 (1 herd), indicating a lower bacterial load in CC23 infections. Median values for the number of infected quarters and somatic cell count (SCC) were numerically but not significantly lower for cows infected with CC23 than for cows with CC1 or CC19. For all CC, an SCC threshold of 200,000 cells/mL was an unreliable indicator of infection status, and prescreening of animals based on SCC as part of S. agalactiae detection and eradication campaigns should be discouraged. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights

  13. Renormalization of Molecular Quasiparticle Levels at Metal-Molecule Interfaces: Trends across Binding Regimes

    DEFF Research Database (Denmark)

    Thygesen, Kristian Sommer; Rubio, Angel

    2009-01-01

    When an electron or a hole is added into an orbital of an adsorbed molecule the substrate electrons will rearrange in order to screen the added charge. This polarization effect reduces the electron addition and removal energies of the adsorbed molecule relative to those of the free molecule. Usin......) polarization of the metal (image charge formation) and (ii) polarization of the molecule via charge transfer across the interface. The importance of (i) and (ii) is found to increase with the metal density of states at the Fermi level and metal-molecule coupling strength, respectively....

  14. Excitation and deexcitation of N2 molecular levels. Induced fluorescence by electrons and laser

    International Nuclear Information System (INIS)

    Perez Fernandez-Mayoralas, A.

    1989-01-01

    The electron impact excitation followed by fluorescence induced by N 2 -laser absorption was used to study the lifetime of the lowest vibrational level of the B 3 π g electronic state of N 2 . The experimental result of this work is 13 + 1 μs. To measure the lifetime of B 3 π g (v=2,3,5,6,7,8) levels the delayed coincidence method by electron impact was use. The lifetime values were compared with recent experimental and theoretical results. The relative intensi-ties of 3 π g --- A 3 Σ Ω + system bands, in the range (6540-10500 A o ) was measured using a hollow cathode lamp as spectral source. The relative transition moments and its dependence versus the r-centroid was obtained. Total cross sections for electron scattering by N molecules in the range 600 - 5000 eV have been obtained from measurements of the attenuation of a linear electron beam. The results have been compared with available experimental cross sections and with theoretical calculations based on the first Born approximation. (Author)

  15. Semiquantitative probe for radiation-induced normal tissue damage at the molecular level

    International Nuclear Information System (INIS)

    Miller, G.; Siemann, D.; Scott, P.; Dawson, D.; Muldrew, K.; Trepanier, P.; McGann, L.

    1986-01-01

    Sheep antibodies to bovine type I collagen were employed in the immunohistochemical detection of type I collagen in lung tissue sections of irradiated LAF1 mice. A video image digitizing system was developed to estimate collagen levels, by assigning a numerical value (0-63) to each of approximately 53,800 picture elements (pixels) in the microscope field, according to the collagen-dependent fluorescence intensity at each locus. For lungs harvested 52 weeks subsequent to graded doses of 60Co gamma radiation between 0 and 10 Gy, a dose-dependent increase in type I collagen was observed in the alveolar walls. A reproducible increase was evident for doses as low as 5 Gy: doses of 7 to 10 Gy elicited type I collagen levels significantly elevated with respect to those of age-matched controls. These results are consistent with a role for type I collagen in the development of radiation-induced pulmonary fibrosis. The assay system developed here will be used to explore the role of connective tissue macromolecules in the development of radiation pneumonitis and fibrosis

  16. Molecular basis for different levels of tet(M) expression in Streptococcus pneumoniae clinical isolates.

    Science.gov (United States)

    Grohs, Patrick; Trieu-Cuot, Patrick; Podglajen, Isabelle; Grondin, Sophie; Firon, Arnaud; Poyart, Claire; Varon, Emmanuelle; Gutmann, Laurent

    2012-10-01

    Seventy-four unrelated clinical isolates of Streptococcus pneumoniae harboring the tet(M) gene were studied. Seven strains with low tetracycline (Tc) MICs (0.25 to 0.5 μg/ml) were found to harbor truncated tet(M) alleles that were inactivated by different frameshift mutations. In contrast, five strains bore deletions in the tet(M) promoter region, among which four displayed increased Tc MICs (16 to 64 μg/ml). The same promoter mutations were detected in Tc-resistant mutants selected in vitro from various susceptible strains. Sequence analysis revealed that these deletions might impede the formation of the transcriptional attenuator located immediately upstream of tet(M). Expression in Enterococcus faecalis of a tet(M) reporter gene transcribed from these promoter mutants conferred a level of Tc resistance similar to that observed in the parental S. pneumoniae strains. These results show that different levels of Tc susceptibility found in clinical isolates of S. pneumoniae can be explained by frameshift mutations within tet(M) and by alterations of the upstream transcriptional attenuator.

  17. Investigation of the chemical mechanisms involved in the electropulsation of membranes at the molecular level.

    Science.gov (United States)

    Breton, Marie; Mir, Lluis M

    2018-02-01

    The chemical consequences of electropulsation on giant unilamellar vesicles (GUVs), in particular the possible oxidation of unsaturated phospholipids, have been investigated by mass spectrometry, flow cytometry and absorbance methods. Pulse application induced oxidation of the GUV phospholipids and the oxidation level depended on the duration of the pulse. Light and O 2 increased the level of pulse-induced lipid peroxidation whereas the presence of antioxidants either in the membrane or in the solution completely suppressed peroxidation. Importantly, pulse application did not create additional reactive oxygen species (ROS) in GUV-free solution. Lipid peroxidation seems to result from a facilitation of the lipid peroxidation by the ROS already present in the solution before pulsing, not from a direct pulse-induced peroxidation. The pulse would facilitate the entrance of ROS in the core of the membrane, allowing the contact between ROS and lipid chains and provoking the oxidation. Our findings demonstrate that the application of electric pulses on cells could induce the oxidation of the membrane phospholipids since cell membranes contain unsaturated lipids. The chemical consequences of electropulsation will therefore have to be taken into account in future biomedical applications of electropulsation since oxidized phospholipids play a key role in many signaling pathways and diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Fermi level alignment in self-assembled molecular layers: the effect of coupling chemistry.

    Science.gov (United States)

    Zangmeister, C D; Robey, S W; van Zee, R D; Kushmerick, J G; Naciri, J; Yao, Y; Tour, J M; Varughese, B; Xu, B; Reutt-Robey, J E

    2006-08-31

    Photoelectron spectroscopy was used to explore changes in Fermi level alignment, within the pi-pi* gap, arising from modifications to the coupling chemistry of conjugated phenylene ethynylene oligomers to the Au surface. Self-assembled monolayers were formed employing either thiol (4,4'-ethynylphenyl-1-benzenethiol or OPE-T) or isocyanide (4,4'-ethynylphenyl-1-benzeneisocyanide or OPE-NC) coupling. The electronic density of states in the valence region of the two systems are nearly identical with the exception of a shift to higher binding energy by about 0.5 eV for OPE-NC. Corresponding shifts appear in C(1s) spectra and in the threshold near E(F). The lack of change in the optical absorption suggests that a rigid shift of the Fermi level within the pi-pi* gap is the major effect of modifying the coupling chemistry. Qualitative consideration of bonding in each case is used to suggest the influence of chemisorption-induced charge transfer as a potential explanation. Connections to other theoretical and experimental work on the effects of varying coupling chemistries are also discussed.

  19. Zebrafish exposure to environmentally relevant concentration of depleted uranium impairs progeny development at the molecular and histological levels.

    Directory of Open Access Journals (Sweden)

    Olivier Armant

    Full Text Available Uranium is an actinide naturally found in the environment. Anthropogenic activities lead to the release of increasing amounts of uranium and depleted uranium (DU in the environment, posing potential risks to aquatic organisms due to radiological and chemical toxicity of this radionucleide. Although environmental contaminations with high levels of uranium have already been observed, chronic exposures of non-human species to levels close to the environmental quality standards remain scarcely characterized. The present study focused on the identification of the molecular pathways impacted by a chronic exposure of zebrafish to 20 μg/L of DU during 10 days. The transcriptomic effects were evaluated by the use of the mRNAseq analysis in three organs of adult zebrafish, the brain the testis and the ovaries, and two developmental stages of the adult fish progeny, two-cells embryo and four-days larvae. The results highlight generic effects on the cell adhesion process, but also specific transcriptomic responses depending on the organ or the developmental stage investigated. The analysis of the transgenerational effects of DU-exposure on the four-day zebrafish larvae demonstrate an induction of genes involved in oxidative response (cat, mpx, sod1 and sod2, a decrease of expression of the two hatching enzymes (he1a and he1b, the deregulation of the expression of gene coding for the ATPase complex and the induction of cellular stress. Electron microscopy analysis of skeletal muscles on the four-days larvae highlights significant histological impacts on the ultrastructure of both the mitochondria and the myofibres. In addition, the comparison with the transcriptomic data obtained for the acetylcholine esterase mutant reveals the induction of protein-chaperons in the skeletal muscles of the progeny of fish chronically exposed to DU, pointing towards long lasting effects of this chemical in the muscles. The results presented in this study support the

  20. Observation of Landau levels in potassium-intercalated graphite under a zero magnetic field.

    Science.gov (United States)

    Guo, Donghui; Kondo, Takahiro; Machida, Takahiro; Iwatake, Keigo; Okada, Susumu; Nakamura, Junji

    2012-01-01

    The charge carriers in graphene are massless Dirac fermions and exhibit a relativistic Landau-level quantization in a magnetic field. Recently, it has been reported that, without any external magnetic field, quantized energy levels have been also observed from strained graphene nanobubbles on a platinum surface, which were attributed to the Landau levels of massless Dirac fermions in graphene formed by a strain-induced pseudomagnetic field. Here we show the generation of the Landau levels of massless Dirac fermions on a partially potassium-intercalated graphite surface without applying external magnetic field. Landau levels of massless Dirac fermions indicate the graphene character in partially potassium-intercalated graphite. The generation of the Landau levels is ascribed to a vector potential induced by the perturbation of nearest-neighbour hopping, which may originate from a strain or a gradient of on-site potentials at the perimeters of potassium-free domains.

  1. Molecular Level Understanding of Sodium Dodecyl Sulfate (SDS) Induced Sol-Gel Transition of Pluronic F127 Using Fisetin as a Fluorescent Molecular Probe.

    Science.gov (United States)

    Mishra, Jhili; Swain, Jitendriya; Mishra, Ashok Kumar

    2018-01-11

    The thermoreversible sol-gel transition of pluronic F127 is markedly altered even with addition of submicellar concentration of sodium dodecyl sulfate (SDS) surfactant. Multiple fluorescence parameters like fluorescence intensity, fluorescence anisotropy and fluorescence lifetime of both the prototropic forms (anion (A - *) and phototautomer FT*) of the photoprototropic fluorescent probe fisetin has been efficiently used to understand the molecular level properties like polarity and microviscosity of the PF127-SDS system as a function of temperature. The SDS-induced increase in the interfacial hydrophobicity level is seen to affect the sol-gel phase transition of PF127 (21-18 °C). The E T (30) polarity parameter value of anionic emission of fisetin suggests that there is a considerable decrease in the polarity of the PF127 medium with increase in temperature and with the addition of SDS. The microviscosity progressively increases from ∼5 mPa s (sol state, 10 °C) to ∼22.01 mPa s (gel state 35 °C) in aqueous solution of PF127. The variation in microviscosity with addition of SDS in PF127-SDS mixed system is significant in sol phase whereas in gel phase this variation is significantly less. Temperature dependent fluorescence lifetime of FT* indicates that there is heterogeneity in distribution of fisetin molecules at different domains of PF127. This work also show-cases the sensitivity of fisetin toward change in polarity and change in sol-gel transition temperature of copolymer PF127 with variation in temperature (both forward and reverse directions) and SDS.

  2. GLUCOSE AND TOTAL PROTEIN LEVEL IN LABORATORY RATS UNDER CONDITIONS OF SHORT-TERM FASTING

    Directory of Open Access Journals (Sweden)

    Damir Suljević

    2013-09-01

    Full Text Available Glucose level (UV enzymatic method and total protein level (Biuret method were measured in the blood samples of the rats exposed to short-term starvation. We found a statistically significant increase in the glucose level in experimental animals during starvation, which is also evident in males and females in the experimental group (p <0.05, while decrease in the total protein level was not statistically significant. During starvation, more significant weight loss was observed in females compared to males.Key words: glucose, total protein, serum, Rattus

  3. Elsevier Trophoblast Research Award lecture: Molecular mechanisms underlying estrogen functions in trophoblastic cells--focus on leptin expression.

    Science.gov (United States)

    Gambino, Y P; Maymó, J L; Pérez Pérez, A; Calvo, J C; Sánchez-Margalet, V; Varone, C L

    2012-02-01

    The steroid hormone 17β-estradiol is an estrogen that influences multiple aspects of placental function and fetal development in humans. During early pregnancy it plays a role in the regulation of blastocyst implantation, trophoblast differentiation and invasiveness, remodeling of uterine arteries, immunology and trophoblast production of hormones such as leptin. Estradiol exerts some effects through the action of classical estrogen receptors ERα and ERβ, which act as ligand-activated transcription factors and regulate gene expression. In addition, estradiol can elicit rapid responses from membrane-associated receptors, like activation of protein-kinase pathways. Thus, the cellular effects of estradiol will depend on the specific receptors expressed and the integration of their signaling events. Leptin, the 16,000MW protein product of the obese gene, was originally considered an adipocyte-derived signaling molecule for the central control of metabolism. However, pleiotropic effects of leptin have been identified in reproduction and pregnancy. The leptin gene is expressed in placenta, where leptin promotes proliferation and survival of trophoblastic cells. Expression of leptin in placenta is highly regulated by key pregnancy molecules as hCG and estradiol. The aim of this paper is to review the molecular mechanisms underlying estrogen functions in trophoblastic cells; focusing on mechanisms involved in estradiol regulation of placental leptin expression. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Catalytic degradation of Acid Orange 7 by manganese oxide octahedral molecular sieves with peroxymonosulfate under visible light irradiation.

    Science.gov (United States)

    Duan, Lian; Sun, Binzhe; Wei, Mingyu; Luo, Shilu; Pan, Fei; Xu, Aihua; Li, Xiaoxia

    2015-03-21

    In this paper, the photodegradation of Acid Orange 7 (AO7) in aqueous solutions with peroxymonosulfate (PMS) was studied with manganese oxide octahedral molecular sieves (OMS-2) as the catalyst. The activities of different systems including OMS-2 under visible light irradiation (OMS-2/Vis), OMS-2/PMS and OMS-2/PMS/Vis were evaluated. It was found that the efficiency of OMS-2/PMS was much higher than that of OMS-2/Vis and could be further enhanced by visible light irradiation. The catalyst also exhibited stable performance for multiple runs. Results from ESR and XPS analyses suggested that the highly catalytic activity of the OMS-2/PMS/Vis system possible involved the activation of PMS to sulfate radicals meditated by the redox pair of Mn(IV)/Mn(III) and Mn(III)/Mn(II), while in the OMS-2/PMS system, only the redox reaction between Mn(IV)/Mn(III) occurred. Several operational parameters, such as dye concentration, catalyst load, PMS concentration and solution pH, affected the degradation of AO7. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Properties of a Laser Shock Wave in Al-Cu Alloy under Elevated Temperatures: A Molecular Dynamics Simulation Study

    Directory of Open Access Journals (Sweden)

    Xiankai Meng

    2017-01-01

    Full Text Available The laser shock wave (LSW generated by the interaction between a laser and a material has been widely used in laser manufacturing, such as laser shock peening and laser shock forming. However, due to the high strain rate, the propagation of LSW in materials, especially LSW at elevated temperatures, is difficult to study through experimental methods. A molecular dynamics simulation was used in this study to investigate the propagation of LSW in an Al-Cu alloy. The Hugoniot relations of LSW were obtained at different temperatures and the effects of elevated temperatures on shock velocity and shock pressure were analyzed. Then the elastic and plastic wave of the LSW was researched. Finally, the evolution of dislocations induced by LSW and its mechanism under elevated temperatures was explored. The results indicate that the shock velocity and shock pressure induced by LSW both decrease with the increasing temperatures. Moreover, the velocity of elastic wave and plastic wave both decrease with the increasing treatment temperature, while their difference decreases as the temperature increases. Moreover, the dislocation atoms increases with the increasing temperatures before 2 ps, while it decreases with the increasing temperatures after 2 ps. The reason for the results is related to the formation and evolution of extended dislocations.

  6. Emerging new tools to study and treat muscle pathologies: genetics and molecular mechanisms underlying skeletal muscle development, regeneration, and disease.

    Science.gov (United States)

    Crist, Colin

    2017-01-01

    Skeletal muscle is the most abundant tissue in our body, is responsible for generating the force required for movement, and is also an important thermogenic organ. Skeletal muscle is an enigmatic tissue because while on the one hand, skeletal muscle regeneration after injury is arguably one of the best-studied stem cell-dependent regenerative processes, on the other hand, skeletal muscle is still subject to many degenerative disorders with few therapeutic options in the clinic. It is important to develop new regenerative medicine-based therapies for skeletal muscle. Future therapeutic strategies should take advantage of rapidly developing technologies enabling the differentiation of skeletal muscle from human pluripotent stem cells, along with precise genome editing, which will go hand in hand with a steady and focused approach to understanding underlying mechanisms of skeletal muscle development, regeneration, and disease. In this review, I focus on highlighting the recent advances that particularly have relied on developmental and molecular biology approaches to understanding muscle development and stem cell function. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  7. Corrosion and inhibition of copper in hydrocarbon solution on a molecular level investigated using neutron reflectometry and XPS

    International Nuclear Information System (INIS)

    Welbourn, Rebecca J.L.; Truscott, C.L.; Skoda, M.W. A.; Zarbakhsh, A.; Clarke, S.M.

    2017-01-01

    Highlights: • Corrosion of CuO by sulphur in oil is inhibited by organic amine but not thiol. • Neutron reflection gives insight into the layer structure and composition. • The most well packed organic layer does not give the best corrosion protection. • Organic thiol selectively removes Cu(II) to leave a Cu(I) surface. - Abstract: The behaviour and molecular structure of three organic additives adsorbed from oil onto a copper surface rich in copper (II) oxide is presented. The variation in the ability of these three agents to prevent corrosion of the copper oxide surface by exposure to sulphur is also included. A combination of visible observations, X-ray photoelectron spectroscopy (XPS) and neutron reflection (NR) are used to characterise both the adsorbed layer and underlying copper oxide. The model additives are chosen to represent ‘effective’, ‘intermediate’ and ‘ineffective’ inhibitors for copper.

  8. Wood and understory production under a range of ponderosa pine stocking levels, Black Hills, South Dakota

    Science.gov (United States)

    Daniel W. Uresk; Carleton B. Edminster; Kieth E. Severson

    2000-01-01

    Stemwood and understory production (kg ha-1) were estimated during 3 nonconsecutive years on 5 growing stock levels of ponderosa pine including clearcuts and unthinned stands. Stemwood production was consistently greater at mid- and higher pine stocking levels, and understory production was greater in stands with less pine; however, there were no...

  9. Breaking a virus: Identifying molecular level failure modes of a viral capsid by multiscale modeling

    Science.gov (United States)

    Krishnamani, V.; Globisch, C.; Peter, C.; Deserno, M.

    2016-10-01

    We use coarse-grained (CG) simulations to study the deformation of empty Cowpea Chlorotic Mottle Virus (CCMV) capsids under uniaxial compression, from the initial elastic response up to capsid breakage. Our CG model is based on the MARTINI force field and has been amended by a stabilizing elastic network, acting only within individual proteins, that was tuned to capture the fluctuation spectrum of capsid protein dimers, obtained from all atom simulations. We have previously shown that this model predicts force-compression curves that match AFM indentation experiments on empty CCMV capsids. Here we investigate details of the actual breaking events when the CCMV capsid finally fails. We present a symmetry classification of all relevant protein contacts and show that they differ significantly in terms of stability. Specifically, we show that interfaces which break readily are precisely those which are believed to form last during assembly, even though some of them might share the same contacts as other non-breaking interfaces. In particular, the interfaces that form pentamers of dimers never break, while the virtually identical interfaces within hexamers of dimers readily do. Since these units differ in the large-scale geometry and, most noticeably, the cone-angle at the center of the 5- or 6-fold vertex, we propose that the hexameric unit fails because it is pre-stressed. This not only suggests that hexamers of dimers form less frequently during the early stages of assembly; it also offers a natural explanation for the well-known β-barrel motif at the hexameric center as a post-aggregation stabilization mechanism. Finally, we identify those amino acid contacts within all key protein interfaces that are most persistent during compressive deformation of the capsid, thereby providing potential targets for mutation studies aiming to elucidate the key contacts upon which overall stability rests.

  10. Emergency dental clinic patients in South Devon, their anxiety levels, expressed demand for treatment under sedation and suitability for management under sedation.

    Science.gov (United States)

    Baker, Robert A; Farrer, Susan; Perkins, Vanessa J; Sanders, Hilary

    2006-01-01

    To assess the anxiety levels of patients attending two salaried dental service emergency clinics, their expressed demand for treatment under sedation, and their medical suitability for dental sedation. A questionnaire survey, incorporating the Modified Dental Anxiety Scale (MDAS) and assessment of American Society of Anesthesiologists' (ASA) physical status classification, of all adult patients attending two emergency dental clinics in Torquay and Newton Abbot. 513 patients returned questionnaires. Only five declined to take part in the study. The mean MDAS for patients attending the two emergency dental clinics was 14.09 (SD 6.04) and 41.9% of patients were classified as dentally anxious (MDAS >15). A preference for treatment under sedation was expressed by 56.3%, of all patients, of whom 50.5% were classified as ASA 1 (without health problems) and would have been suitable for sedation in primary dental care. The reported dental anxiety levels of patients attending the two emergency dental clinics were found to be much higher than those found by previous studies in general dental practice and at dental school emergency clinics. There was a high expressed demand for treatment under sedation. Further studies are needed to assess the levels of dental anxiety seen at other dental emergency clinics and a health needs assessment to determine need as opposed to expressed demand.

  11. [Effects of inoculating AM fungi on physiological characters and nutritional components of Astragalus membranaceus under different N application levels].

    Science.gov (United States)

    He, Xue-li; Liu, Ti; Zhao, Li-li

    2009-09-01

    A pot culture with unsterilized soil as growth substrate showed that AM fungi had significant effects on the growth of Astragalus membranaceus (Fabaceae) under different N application levels. Inoculation with AM fungi promoted the AM infection of A. membranaceus roots, but high N application level suppressed the infection. Inoculating AM fungi increased the growth rate, soluble protein and sugar contents, and SOD, POD and CAT activities of A. membranaceus. Under 50 and 100 mg x kg(-1) of N application, new bands of POD isozyme occurred in inoculated plants, and the contents of flavonoid, N, and P in A. membranaceus also had definite increase. The best inoculation effect was observed under the N application level of 50-100 mg N x kg(-1) soil.

  12. Committed sea-level rise under the Paris Agreement and the legacy of delayed mitigation action.

    Science.gov (United States)

    Mengel, Matthias; Nauels, Alexander; Rogelj, Joeri; Schleussner, Carl-Friedrich

    2018-02-20

    Sea-level rise is a major consequence of climate change that will continue long after emissions of greenhouse gases have stopped. The 2015 Paris Agreement aims at reducing climate-related risks by reducing greenhouse gas emissions to net zero and limiting global-mean temperature increase. Here we quantify the effect of these constraints on global sea-level rise until 2300, including Antarctic ice-sheet instabilities. We estimate median sea-level rise between 0.7 and 1.2 m, if net-zero greenhouse gas emissions are sustained until 2300, varying with the pathway of emissions during this century. Temperature stabilization below 2 °C is insufficient to hold median sea-level rise until 2300 below 1.5 m. We find that each 5-year delay in near-term peaking of CO 2 emissions increases median year 2300 sea-level rise estimates by ca. 0.2 m, and extreme sea-level rise estimates at the 95th percentile by up to 1 m. Our results underline the importance of near-term mitigation action for limiting long-term sea-level rise risks.

  13. Underlying data for derived emergency reference levels. Post-Chernobyl action

    International Nuclear Information System (INIS)

    Sinnaeve, J.; Gerber, G.

    1991-01-01

    After an accidental release of radioactive material to the atmosphere leading to significant off-site contamination, various countermeasures are needed to reduce the radiation exposure of the population. These may include measures to reduce the consumption of contaminated foodstuffs. This report is concerned with the underlying information required for calculating when and if such countermeasures as regards foodstuffs should be introduced. The work in this report was sponsored by the Commission of the European Communities as one of a series of post-Chernobyl actions under its radiation protection programme

  14. Interactions between proteins and carbon-based nanoparticles: exploring the origin of nanotoxicity at the molecular level.

    Science.gov (United States)

    Zuo, Guanghong; Kang, Seung-Gu; Xiu, Peng; Zhao, Yuliang; Zhou, Ruhong

    2013-05-27

    The widespread application of nanomaterials has spurred an interest in the study of interactions between nanoparticles and proteins due to the biosafety concerns of these nanomaterials. In this review, a summary is presented of some of the recent studies on this important subject, especially on the interactions of proteins with carbon nanotubes (CNTs) and metallofullerenols. Two potential molecular mechanisms have been proposed for CNTs' inhibition of protein functions. The driving forces of CNTs' adsorption onto proteins are found to be mainly hydrophobic interactions and the so-called π-π stacking between CNTs' carbon rings and proteins' aromatic residues. However, there is also recent evidence showing that endohedral metallofullerenol Gd@C82 (OH)22 can be used to inhibit tumor growth, thus acting as a potential nanomedicine. These recent findings have provided a better understanding of nanotoxicity at the molecular level and also suggested therapeutic potential by using nanoparticles' cytotoxicity against cancer cells. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Molecular-level understanding of the adsorption mechanism of a graphite-binding peptide at the water/graphite interface.

    Science.gov (United States)

    Penna, M J; Mijajlovic, M; Tamerler, C; Biggs, M J

    2015-07-14

    The association of proteins and peptides with inorganic material has vast technological potential. An understanding of the adsorption of peptides at liquid/solid interfaces on a molecular-level is fundamental to fully realising this potential. Combining our prior work along with the statistical analysis of 100+ molecular dynamics simulations of adsorption of an experimentally identified graphite binding peptide, GrBP5, at the water/graphite interface has been used here to propose a model for the adsorption of a peptide at a liquid/solid interface. This bottom-up model splits the adsorption process into three reversible phases: biased diffusion, anchoring and lockdown. Statistical analysis highlighted the distinct roles played by regions of the peptide studied here throughout the adsorption process: the hydrophobic domain plays a significant role in the biased diffusion and anchoring phases suggesting that the initial impetus for association between the peptide and the interface may be hydrophobic in origin; aromatic residues dominate the interaction between the peptide and the surface in the adsorbed state and the polar region in the middle of the peptide affords a high conformational flexibility allowing strongly interacting residues to maximise favourable interactions with the surface. Reversible adsorption was observed here, unlike in our prior work focused on a more strongly interacting surface. However, this reversibility is unlikely to be seen once the peptide-surface interaction exceeds 10 kcal mol(-1).

  16. Molecular alterations underlying the spontaneous and γ-ray-induced point mutations at the white locus of Drosophila Melanogaster

    International Nuclear Information System (INIS)

    Aleksandrova, M.V.; Lapidus, I.L.; Aleksandrov, I.D.; Karpovskij, A.L.

    1996-01-01

    The white locus in D.Melanogaster was selected as a target gene for the study of the mutational spectra of spontaneously arising and radiation-induced gene mutations in a whole organism. Analysis of 6 spontaneous and 73 γ-ray-induced white mutations by a combination of cytological, genetic and molecular techniques revealed that on the chromosomal and genetic levels all spontaneous mutations showed themselves to be point mutants. The share of such mutants among all heritable radiation-induced gene mutations is about 40%, whereas the rest ones are due to exchange breaks (8%) as well as multilocus, single-locus or partial-locus (intragenic) deletions (52%). The DNAs from 4 spontaneous and 17 γ-ray-induced point mutants were analysed by Southern blot-hybridization. The three spontaneous and 7 radiation mutants showed an altered DNA sequence at the left (distal) half of the white gene due to insertion or DNA rearrangement. The rest (58%) of the radiation-induced point mutations did not indicate any alternations in this part of the gene as detected by this technique and probes employed. 15 refs., 3 figs., 1 tab

  17. High–Level Control System for Biomimetic Autonomous Under-water Vehicle

    Directory of Open Access Journals (Sweden)

    Praczyk Tomasz

    2017-01-01

    Full Text Available Usually, a rough software architecture designed for a robot can be can be shortly presented in the form of layers. The lowest layer is responsible for direct control of the hardware, i.e. engines, energy system, sensors, navigation devices, etc. A next layer is a low–level control which knows how to use the hardware in order to achieve a desired state of the robot, e.g. to stay on a desired course. And the last layer, the layer which is the nearest to the human–operator, is a high–level control which decides how to use the low–level control and sometimes also individual pieces of the hardware to achieve predefined objectives. The paper describes architecture, tasks and operation of the high–level control system (HLCS designed for Biomimetic Autonomous Underwater Vehicle (BAUV.

  18. Change in the level of strength and endurance development of 5-6 grades pupils under cheerleading exercises influence

    Directory of Open Access Journals (Sweden)

    Tetyana Bala

    2015-06-01

    Full Text Available Purpose: determine the degree of change in the level of strength and endurance development of 5-6 grades pupils under cheerleading exercises influence. Material and Methods: theoretical analysis and generalization of scientific and methodical literature, pedagogical testing, pedagogical experiment and mathematical statistics methods. Results: parameters of strength and endurance development level are presented with their degree of change under cheerleading exercises influence for 5-6 grades pupils of secondary school. Conclusions: cheerleading exercises usage has positive influence on demonstrated strength and endurance degree of secondary school children by all investigated parameters.

  19. A Global Chance-Constraint for Stochastic Inventory Systems under Service Level Constraints

    NARCIS (Netherlands)

    Rossi, R.; Tarim, S.A.; Hnich, B.; Prestwich, S.

    2008-01-01

    We consider a class of production/inventory control problems that has a single product and a single stocking location, for which a stochastic demand with a known non-stationary probability distribution is given. Under the widely-known replenishment cycle policy the problem of computing policy

  20. Assessment of safety levels and microscopic traffic simulation modeling tool under the IntelliDrive environment

    NARCIS (Netherlands)

    Roelofsen, M.; Bie, Jing; Lisheng, J.; van Arem, Bart

    2010-01-01

    In this paper we propose a novel design for the Lane Change Assistant (LCA). For drivers on the highway, LCA advises them on whether it is safe to change lanes under the current traffic conditions. We focus on how the LCA can provide a reliable advice in practice by considering the issues of

  1. Evaluation of an Improved Branch-Site Likelihood Method for Detecting Positive Selection at the Molecular Level

    DEFF Research Database (Denmark)

    Zhang, Jianzhi; Nielsen, Rasmus; Yang, Ziheng

    2005-01-01

    been developed to test positive selection that acts on given branches (branch methods) or on a subset of sites (site methods). Recently, Yang, Z., and R. Nielsen (2002. Codon-substitution models for detecting molecular adaptation at individual sites along specific lineages. Mol. Biol. Evol. 19......Detecting positive Darwinian selection at the DNA sequence level has been a subject of considerabl