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Sample records for additional functional roles

  1. Recognition of additional roles for immunoglobulin domains in immune function

    PubMed Central

    Cannon, John P.; Dishaw, Larry J.; Haire, Robert N.; Litman, Ronda T.; Ostrov, David A.; Litman, Gary W.

    2010-01-01

    Characterization of immune receptors found in phylogenetically disparate species at the genetic, structural and functional levels has provided unique insight into the evolutionary acquisition of immune function. The roles of variable- and intermediate-type immunoglobulin (Ig) domains in direct recognition of ligands and other functions are far wider than previously anticipated. Common mechanisms of multigene family diversification and expansion as well as unique adaptations that relate to function continue to provide unique insight into the numerous patterns, processes and complex interactions that regulate the host response to infectious challenge. PMID:20004115

  2. Functional Generalized Additive Models.

    PubMed

    McLean, Mathew W; Hooker, Giles; Staicu, Ana-Maria; Scheipl, Fabian; Ruppert, David

    2014-01-01

    We introduce the functional generalized additive model (FGAM), a novel regression model for association studies between a scalar response and a functional predictor. We model the link-transformed mean response as the integral with respect to t of F{X(t), t} where F(·,·) is an unknown regression function and X(t) is a functional covariate. Rather than having an additive model in a finite number of principal components as in Müller and Yao (2008), our model incorporates the functional predictor directly and thus our model can be viewed as the natural functional extension of generalized additive models. We estimate F(·,·) using tensor-product B-splines with roughness penalties. A pointwise quantile transformation of the functional predictor is also considered to ensure each tensor-product B-spline has observed data on its support. The methods are evaluated using simulated data and their predictive performance is compared with other competing scalar-on-function regression alternatives. We illustrate the usefulness of our approach through an application to brain tractography, where X(t) is a signal from diffusion tensor imaging at position, t, along a tract in the brain. In one example, the response is disease-status (case or control) and in a second example, it is the score on a cognitive test. R code for performing the simulations and fitting the FGAM can be found in supplemental materials available online. PMID:24729671

  3. Phylogenetic Analyses and Characterization of RNase X25 from Drosophila melanogaster Suggest a Conserved Housekeeping Role and Additional Functions for RNase T2 Enzymes in Protostomes

    PubMed Central

    Ambrosio, Linda; Bailey, Ryan; Ding, Jian; MacIntosh, Gustavo C.

    2014-01-01

    Ribonucleases belonging to the RNase T2 family are enzymes associated with the secretory pathway that are almost absolutely conserved in all eukaryotes. Studies in plants and vertebrates suggest they have an important housekeeping function in rRNA recycling. However, little is known about this family of enzymes in protostomes. We characterized RNase X25, the only RNase T2 enzyme in Drosophila melanogaster. We found that RNase X25 is the major contributor of ribonuclease activity in flies as detected by in gel assays, and has an acidic pH preference. Gene expression analyses showed that the RNase X25 transcript is present in all adult tissues and developmental stages. RNase X25 expression is elevated in response to nutritional stresses; consistent with the hypothesis that this enzyme has a housekeeping role in recycling RNA. A correlation between induction of RNase X25 expression and autophagy was observed. Moreover, induction of gene expression was triggered by oxidative stress suggesting that RNase X25 may have additional roles in stress responses. Phylogenetic analyses of this family in protostomes showed that RNase T2 genes have undergone duplication events followed by divergence in several phyla, including the loss of catalytic residues, and suggest that RNase T2 proteins have acquired novel functions. Among those, it is likely that a role in host immunosuppression evolved independently in several groups, including parasitic Platyhelminthes and parasitoid wasps. The presence of only one RNase T2 gene in the D. melanogaster genome, without any other evident secretory RNase activity detected, makes this organism an ideal system to study the cellular functions of RNase T2 proteins associated with RNA recycling and maintenance of cellular homeostasis. On the other hand, the discovery of gene duplications in several protostome genomes also presents interesting new avenues to study additional biological functions of this ancient family of proteins. PMID:25133712

  4. Roles for RNA in Telomerase Nucleotide and Repeat Addition Processivity

    PubMed Central

    Lai, Cary K.; Miller, Michael C.; Collins, Kathleen

    2010-01-01

    Summary Telomerase is a ribonucleoprotein reverse transcriptase with two subunits critical for catalytic activity, the protein telomerase reverse transcriptase (TERT) and telomerase RNA. In this study, we establish additional roles of the telomerase RNA subunit by demonstrating that RNA motifs stimulate the processivity of nucleotide and repeat addition. These functions are both functionally and physically separable from the roles of other RNA motifs in establishing a properly defined template. Binding of Tetrahymena telomerase RNA stem IV to TERT enhances nucleotide addition processivity, while a cooperation of the RNA pseudoknot and stem IV promotes repeat addition processivity. The low processivity of DNA synthesis by telomerase ribonucleoproteins lacking the pseudoknot and/or stem IV can be rescued by addition of the deleted region in trans. These findings demonstrate RNA elements with roles in telomerase elongation processivity that are distinct from RNA elements that specify the internal template. PMID:12820978

  5. Deciphering the roles of multiple additives in organocatalyzed Michael additions.

    PubMed

    Günler, Z Inci; Companyó, Xavier; Alfonso, Ignacio; Burés, Jordi; Jimeno, Ciril; Pericàs, Miquel A

    2016-05-21

    The synergistic effects of multiple additives (water and acetic acid) on the asymmetric Michael addition of acetone to nitrostyrene catalyzed by primary amine-thioureas (PAT) were precisely determined. Acetic acid facilitates hydrolysis of the imine intermediates, thus leading to catalytic behavior, and minimizes the formation of the double addition side product. In contrast, water slows down the reaction but minimizes catalyst deactivation, eventually leading to higher final yields. PMID:27128165

  6. Characterizing neuromorphologic alterations with additive shape functionals

    NASA Astrophysics Data System (ADS)

    Barbosa, M. S.; Costa, L. Da F.; Bernardes, E. S.; Ramakers, G.; van Pelt, J.

    2004-01-01

    The complexity of a neuronal cell shape is known to be related to its function. Specifically, among other indicators, a decreased complexity in the dendritic trees of cortical pyramidal neurons has been associated with mental retardation. In this paper we develop a procedure to address the characterization of morphological changes induced in cultured neurons by over-expressing a gene involved in mental retardation. Measures associated with the multiscale connectivity, an additive image functional, are found to give a reasonable separation criterion between two categories of cells. One category consists of a control group and two transfected groups of neurons, and the other, a class of cat ganglionary cells. The reported framework also identified a trend towards lower complexity in one of the transfected groups. Such results establish the suggested measures as an effective descriptors of cell shape.

  7. Regulation of steroid hormone receptors and coregulators during the cell cycle highlights potential novel function in addition to roles as transcription factors

    PubMed Central

    Zheng, Yingfeng; Murphy, Leigh C.

    2016-01-01

    Cell cycle progression is tightly controlled by several kinase families including Cyclin-Dependent Kinases, Polo-Like Kinases, and Aurora Kinases. A large amount of data show that steroid hormone receptors and various components of the cell cycle, including cell cycle regulated kinases, interact, and this often results in altered transcriptional activity of the receptor. Furthermore, steroid hormones, through their receptors, can also regulate the transcriptional expression of genes that are required for cell cycle regulation. However, emerging data suggest that steroid hormone receptors may have roles in cell cycle progression independent of their transcriptional activity. The following is a review of how steroid receptors and their coregulators can regulate or be regulated by the cell cycle machinery, with a particular focus on roles independent of transcription in G2/M. PMID:26778927

  8. Role of edible film and coating additives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edible films and coatings have received increasing interest because films and coatings can carry a diversity of functional ingredients. Plasticizers, such as glycerol, acetylated monoglycerides, polyethylene glycol, and sucrose are often used to modify the mechanical properties of the film or coatin...

  9. Functional roles of fructose.

    PubMed

    Kim, Jinyoung; Song, Gwonhwa; Wu, Guoyao; Bazer, Fuller W

    2012-06-19

    During the periimplantation period of pregnancy, pig blastocysts undergo morphological changes and differentiation requiring secretion and transport of nutrients (histotroph) into the uterine lumen. Of these nutrients, glucose is converted to fructose, an isomer of glucose, by conceptus trophectoderm. Although glucose is an energy source for proliferation and growth of mammalian cells, the role of fructose in uterine histotroph is unclear although it is the most abundant hexose sugar in fetal blood and fluids of ungulate mammals (e.g., cows, sheep, and pigs). In this study, we used porcine trophectoderm cells to determine that fructose increased cell proliferation, as did glucose. Western blot analyses of porcine trophectoderm cell extracts revealed that fructose increased the abundance of phosphorylated-RPS6K, -EIF4EBP1, and -RPS6 over basal levels within 30 min, and those levels remained elevated to 120 min. Phosphorylation of both RPS6K and EIF4EBP1 proteins in response to fructose was inhibited by inhibitors of both PI3K and MTOR. Further, when we investigated the inhibition of glutamine-fructose-6-phosphate transaminase 1 (GFPT1) by azaserine (an inhibitor of GFPT1) and GFPT1 siRNA, we found that MTOR-RPS6K and MTOR-EIF4EBP1 signaling in response to fructose is mediated via GFPT1 activation and the hexosamine pathway. We further demonstrated that fructose stimulates the production of hyaluronic acid via GFPT1 and the hexosamine biosynthesis pathway. Collectively, these results demonstrate critical roles for fructose that are mediated via the hexosamine biosynthesis pathway to stimulate MTOR cell signaling, proliferation of porcine trophectoderm cells, and synthesis of hyaluronic acid, a significant glycosaminoglycan in the pregnant uterus. PMID:22623530

  10. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  11. Adult Roles & Functions. Objective Based Evaluation System.

    ERIC Educational Resources Information Center

    West Virginia State Vocational Curriculum Lab., Cedar Lakes.

    This book of objective-based test items is designed to be used with the Adult Roles and Functions curriculum for a non-laboratory home economic course for grades eleven and twelve. It contains item banks for each cognitive objective in the curriculum. In addition, there is a form for the table of specifications to be developed for each unit. This…

  12. Roles of additives and surface control in slurry atomization

    SciTech Connect

    Tsai, S.C.

    1992-01-01

    This project studies the rheology and airblast atomization of micronized coal slurries. Its major objectives are (1) to promote further understanding of the mechanisms and the roles of additives in airblast atomization of coal water slurry (CWS), and (2) to investigate the impacts of coal particle surface properties and interparticle forces on CWS rheology. We have found that the flow behavior index (n) of a suspension (or slurry) is determined by the relative importance of the interparticle van der Waals attraction and the interparticle electrostatic repulsion. The interparticle attraction, measured by the Hamaker constant scaled to the thermal energy at 25[degrees]C (A/kT), causes particle aggregation, which breaks down at high shear rates, and thus leads to slurry pseudoplastic behavior (n< 1). At a constant particle volume fraction and surface charge density (qualitatively measured by the zeta potential in deionized water), n decreases linearly as A/kT increases. The relative viscosity of the pseudoplastic suspension with respect to that of the suspending liquid is found to be independent of particle density and correlate well with the particle Peclet number which equals the particle diffusional relaxation time multiplied by shear rate. Specifically, the relative viscosities of the pseudoplastic glycerol/water coal slurry and the ethylene glycol/glycerol sand slurry, at same volume fractions as well as similar particle size distributions and liquid viscosities, as functions of the particle Peclet number fall along the same line.

  13. Density functional for ternary non-additive hard sphere mixtures.

    PubMed

    Schmidt, Matthias

    2011-10-19

    Based on fundamental measure theory, a Helmholtz free energy density functional for three-component mixtures of hard spheres with general, non-additive interaction distances is constructed. The functional constitutes a generalization of the previously given theory for binary non-additive mixtures. The diagrammatic structure of the spatial integrals in both functionals is of star-like (or tree-like) topology. The ternary diagrams possess a higher degree of complexity than the binary diagrams. Results for partial pair correlation functions, obtained via the Ornstein-Zernike route from the second functional derivatives of the excess free energy functional, agree well with Monte Carlo simulation data. PMID:21946780

  14. Some new addition formulae for Weierstrass elliptic functions

    PubMed Central

    Eilbeck, J. Chris; England, Matthew; Ônishi, Yoshihiro

    2014-01-01

    We present new addition formulae for the Weierstrass functions associated with a general elliptic curve. We prove the structure of the formulae in n-variables and give the explicit addition formulae for the 2- and 3-variable cases. These new results were inspired by new addition formulae found in the case of an equianharmonic curve, which we can now observe as a specialization of the results here. The new formulae, and the techniques used to find them, also follow the recent work for the generalization of Weierstrass functions to curves of higher genus. PMID:25383018

  15. Hyperbolic tangential function-based progressive addition lens design.

    PubMed

    Qiu, Gufeng; Cui, Xudong

    2015-12-10

    The diopter distribution is key to the successful design of a progressive addition lens. A hyperbolic tangential function is then introduced to describe well the desired diopter distribution on the lens. Simulation and fabrication show that the astigmia on the whole surface is very close to the addition, exhibiting superior performance than that of currently used high-order polynomials and cosine functions. Our investigations found that once the diopter distribution design is reasonable, both the direct and indirect methods of constructing a progressive addition lens can give consistent results. With this function we are able to effectively control the design of critical areas, the position, sizes of far-view and near-view zones, as well as the channel of the lens. This study would provide an efficient way to customize different progressive lenses not only for presbyopia, but also for anti-fatigue, office progressive usages, etc. PMID:26836863

  16. [Roles of additives and surface control in slurry atomization

    SciTech Connect

    Tsai, S.C.

    1992-06-01

    As reported in the quarterly report of March of 1992, the relative viscosity of a Newtonian Coal Water Slurry (CWS) in the presence of an anionic polymeric dispersant is an order of magnitude higher than the prediction of the well established Krieger-Dougherty Equation which describes the relative viscosity of a non-aggregated Newtonian suspension as a function of particle volume fraction. Note that the anionic dispersant is used in such a quantity that the resulting interparticle electrostatic repulsion counter-balances the interparticle van der Waals attraction. Investigation continues to determine the mechanisms of such excess energy dissipation under shear. New experimental results are presented in this report to verify the role of the anionic polymeric dispersant in such excess energy dissipation of CWS.

  17. Application of rational functions for the standard addition method.

    PubMed

    Gorazda, Katarzyna; Michałowska-Kaczmarczyk, Anna M; Asuero, Agustin G; Michałowski, Tadeusz

    2013-11-15

    Some rational functions are considered as the basis for calculation of unknown concentration (x0) of an analyte X determined according to the standard addition method (SAM). The correction for dilution of the sample tested during addition of successive increments of standard(ised) solution of X is involved in the related algorithm applied for calculation of the x0 value. The formulae derived were put in context with experimental data, obtained according to the AAS method from Cu-measurements in samples obtained by digestion of an ash obtained from incinerated sludge. It was stated that the use of rational functions for modeling purposes strengthens the robustness of the results thus obtained. PMID:24148496

  18. Functional Role of Ribosomal Signatures

    PubMed Central

    Chen, Ke; Eargle, John; Sarkar, Krishnarjun; Gruebele, Martin; Luthey-Schulten, Zaida

    2010-01-01

    Although structure and sequence signatures in ribosomal RNA and proteins are defining characteristics of the three domains of life and instrumental in constructing the modern phylogeny, little is known about their functional roles in the ribosome. In this work, the largest coevolving RNA/protein signatures in the bacterial 30S ribosome are investigated both experimentally and computationally through all-atom molecular-dynamics simulations. The complex includes the N-terminal fragment of the ribosomal protein S4, which is a primary binding protein that initiates 30S small subunit assembly from the 5′ domain, and helix 16 (h16), which is part of the five-way junction in 16S rRNA. Our results show that the S4 N-terminus signature is intrinsically disordered in solution, whereas h16 is relatively stable by itself. The dynamic disordered property of the protein is exploited to couple the folding and binding process to the five-way junction, and the results provide insight into the mechanism for the early and fast binding of S4 in the assembly of the ribosomal small subunit. PMID:21156135

  19. Understanding composite explosive energetics: I, The role of metallic additives

    SciTech Connect

    Tao, W.C.; Tarver, C.M.; Breithaupt, D.R.; McGuire, R.R.; Ornellas, D.L.

    1990-01-01

    Composite explosives (CE) have found major applications in air blast, cratering, fragmentation, underwater applications, and other commercial and military systems in which prompt delivery of the available energy is not a primary requirement. In direct metal acceleration applications, composite explosives have not generally been effective because their potential energy is transformed to kinetic energy over time periods extending to tens of microseconds. We are interested in defining the rate determining steps and understanding the chemical interactions between different components in the composite explosive formulation in order to determine the partitioning of the available energy. In this study, we investigate the role of the metallic additive in a bicomponent composite explosive consisting of PETN and aluminum. Of specific interests are the early time performance of and the extent of aluminum reaction in the composite formulation. For formulations loaded with 5 wt% and 10 wt% of 5 micron spherical aluminum, we found that 100% of the aluminum reacted within the first microsecond of volume expansion. The extent of aluminum reaction with the PETN detonation products is reduced to about 65% for composite formulations loaded with 20 wt% aluminum. It is evident from the results of a series of scaling experiments that the detonation behavior of the PETN-aluminum bicomponent composite explosive is nonideal. 6 refs., 11 figs., 2 tabs.

  20. Radical additions to chiral hydrazones: stereoselectivity and functional group compatibility.

    PubMed

    Friestad, Gregory K

    2012-01-01

    Free radical additions to imino compounds offer increased synthetic accessibility of chiral amines, but lack of general methods for stereocontrol has hindered their development. This review focuses on two asymmetric amine synthesis strategies designed to address this problem, with emphasis on addition of functionalized radicals which may facilitate applications to synthesis of complex targets. First, chiral N-acylhydrazones are acceptors for intermolecular radical additions of a wide range of primary, secondary, and tertiary alkyl halides to the C=N bond, with radicals generated under manganese-, tin-, or boron-mediated conditions. A variety of aldehydes and ketones serve as viable precursors for the chiral hydrazones, and the highly stereoselective reactions tolerate electrophilic functionality in both coupling components. Second, radical precursors may be linked to chiral α-hydroxyhydrazones via a silicon tether to the hydroxyl group; conformational constraints impart stereocontrol during 5-exo radical cyclization under stannyl- or thiyl-mediated conditions. The silicon tether may later be removed to reveal the formal adducts of hydroxymethyl, vinyl, acetyl, and 2-oxoethyl radicals to the C=N bond. Methodology development and applications to biologically important targets are discussed. PMID:21842359

  1. Development of additional tasks for the executive function performance test.

    PubMed

    Hahn, Bridget; Baum, Carolyn; Moore, Jennifer; Ehrlich-Jones, Linda; Spoeri, Susan; Doherty, Meghan; Wolf, Timothy J

    2014-01-01

    OBJECTIVE. The Executive Function Performance Test (EFPT) is a reliable and valid performance-based assessment of executive function for people with stroke. The objective of this study was to enhance the clinical utility of the EFPT by developing and testing additional tasks for the EFPT in the Alternate EFPT (aEFPT). METHOD. We performed a cross-sectional study with poststroke participants (n = 25) and healthy control participants (n = 25). All participants completed a neuropsychological assessment battery and both the EFPT and the aEFPT. RESULTS. No statistically significant differences were found between the EFPT and the aEFPT when examining total scores, construct scores, and two overall task scores. Correlations between the aEFPT and the neuropsychological measures were adequate to strong (r2s = .59-.83). CONCLUSION. The aEFPT tasks are comparable to the original EFPT tasks, providing occupational therapy practitioners with additional tasks that can be used clinically to identify performance-based executive function deficits in people with stroke. PMID:25397771

  2. Functional role of autophagy in gastric cancer

    PubMed Central

    2016-01-01

    Autophagy is a highly regulated catabolic pathway responsible for the degradation of long-lived proteins and damaged intracellular organelles. Perturbations in autophagy are found in gastric cancer. In host gastric cells, autophagy can be induced by Helicobacter pylori (or H. pylori) infection, which is associated with the oncogenesis of gastric cancer. In gastric cancer cells, autophagy has both pro-survival and pro-death functions in determining cell fate. Besides, autophagy modulates gastric cancer metastasis by affecting a wide range of pathological events, including extracellular matrix (ECM) degradation, epithelial-to-mesenchymal transition (EMT), tumor angiogenesis, and tumor microenvironment. In addition, some of the autophagy-related proteins, such as Beclin 1, microtubule-associated protein 1 light chain 3 (MAP1-LC3), and p62/sequestosome 1 (SQSTM1) have certain prognostic values for gastric cancer. In this article, we review the recent studies regarding the functional role of autophagy in gastric cancer. PMID:26910278

  3. Fuzzy Number Addition with the Application of Horizontal Membership Functions.

    PubMed

    Piegat, Andrzej; Pluciński, Marcin

    2015-01-01

    The paper presents addition of fuzzy numbers realised with the application of the multidimensional RDM arithmetic and horizontal membership functions (MFs). Fuzzy arithmetic (FA) is a very difficult task because operations should be performed here on multidimensional information granules. Instead, a lot of FA methods use α-cuts in connection with 1-dimensional classical interval arithmetic that operates not on multidimensional granules but on 1-dimensional intervals. Such approach causes difficulties in calculations and is a reason for arithmetical paradoxes. The multidimensional approach allows for removing drawbacks and weaknesses of FA. It is possible thanks to the application of horizontal membership functions which considerably facilitate calculations because now uncertain values can be inserted directly into equations without using the extension principle. The paper shows how the addition operation can be realised on independent fuzzy numbers and on partly or fully dependent fuzzy numbers with taking into account the order relation and how to solve equations, which can be a difficult task for 1-dimensional FAs. PMID:26199953

  4. Nonlinear responses in salt marsh functioning to increased nitrogen addition.

    PubMed

    Vivanco, Lucía; Irvine, Irina C; Martiny, Jennifer B H

    2015-04-01

    Salt marshes provide storm protection to shorelines, sequester carbon (C), and mitigate coastal eutrophication. These valuable coastal ecosystems are confronted with increasing nitrogen (N) inputs from anthropogenic sources, such as agricultural runoff, wastewater, and atmospheric deposition. To inform predictions of salt marsh functioning and sustainability in the future, we characterized the response of a variety of plant, microbial, and sediment responses to a seven-level gradient of N addition in three Californian salt marshes after 7 and 14 months of N addition. The marshes showed variable responses to the experimental N gradient that can be grouped as neutral (root biomass, sediment respiration, potential carbon mineralization, and potential net nitrification), linear (increasing methane flux, decreasing potential net N mineralization, and increasing sediment inorganic N), and nonlinear (saturating aboveground plant biomass and leaf N content, and exponentially increasing sediment inorganic and organic N). The three salt marshes showed quantitative differences in most ecosystem properties and processes rates; however, the form of the response curves to N addition were generally consistent across the three marshes, indicating that the responses observed may be applicable to other marshes in the region. Only for sediment properties (inorganic and organic N pool) did the shape of the response differ significantly between marshes. Overall, the study suggests salt marshes are limited in their ability to sequester C and N with future increases in N, even without further losses in marsh area. PMID:26230015

  5. From waste to functional additive: toughening epoxy resin with lignin.

    PubMed

    Liu, Wanshuang; Zhou, Rui; Goh, Hwee Li Sally; Huang, Shu; Lu, Xuehong

    2014-04-23

    A novel approach to toughen epoxy resin with lignin, a common waste material from the pulp and paper industry, is presented in this article. First, carboxylic acid-functionalized alkali lignin (AL-COOH) was prepared and subsequently incorporated into anhydride-cured epoxy networks via a one-pot method. The results of mechanical tests show that covalent incorporation of rigid AL-COOH into epoxy networks can significantly toughen the epoxy matrix without deteriorating its tensile strength and modulus. The addition of 1.0 wt % AL-COOH gives increases of 68 and 164% in the critical stress intensity factor (K(IC)) and critical strain energy release rate (G(IC)), respectively, relative to that of neat epoxy. This article opens up the possibility of utilizing low-cost and renewable lignin feedstocks as effective toughening agents for thermoset polymers. PMID:24660855

  6. The Role of Drugs, Diet, and Food Additives in Hyperactivity.

    ERIC Educational Resources Information Center

    Harshbarger, Mary E.

    A variety of causes have been suggested for hyperactivity: anoxia and other adverse birth conditions, genetic factors, delayed maturation, maternal smoking and drinking during pregnancy, interaction of temperament and environment, lead poisoning, radiation stress, allergy and food additives, and deprivation of required stimulation. Treatments…

  7. Children's Additive Concepts: Promoting Understanding and the Role of Inhibition

    ERIC Educational Resources Information Center

    Robinson, Katherine M.; Dube, Adam K.

    2013-01-01

    This study investigated the promotion of children's understanding and acquisition of arithmetic concepts and the effects of inhibitory skills. Children in Grades 3, 4, and 5 solved two sets of three-term addition and subtraction problems (e.g., 3 + 24 - 24, 3 + 24 - 22) and completed an inhibition task. Half of the participants received a…

  8. The functional role of time compression.

    PubMed

    Zimmermann, Eckart; Derichs, Christina; Fink, Gereon R

    2016-01-01

    Multisensory integration provides continuous and stable perception from separate sensory inputs. Here, we investigated the functional role of temporal binding between the visual and the tactile senses. To this end we used the paradigm of compression that induces shifts in time when probe stimuli are degraded, e.g., by a visual mask (Zimmermann et al. 2014). Subjects had to estimate the duration of temporal intervals of 500 ms defined by a tactile and a visual, masked stimulus. We observed a strong (~100 ms) underestimation of the temporal interval when the stimuli from both senses appeared to occur at the same position in space. In contrast, when the positions of the visual and tactile stimuli were spatially separate, interval perception was almost veridical. Temporal compression furthermore depended on the correspondence of probe features and was absent when the orientation of the tactile and visual probes was incongruent. An additional experiment revealed that temporal compression also occurs when objects were presented outside the attentional focus. In conclusion, these data support a role for spatiotemporal binding in temporal compression, which is at least in part selective for object features. PMID:27180810

  9. The functional role of time compression

    PubMed Central

    Zimmermann, Eckart; Derichs, Christina; Fink, Gereon R.

    2016-01-01

    Multisensory integration provides continuous and stable perception from separate sensory inputs. Here, we investigated the functional role of temporal binding between the visual and the tactile senses. To this end we used the paradigm of compression that induces shifts in time when probe stimuli are degraded, e.g., by a visual mask (Zimmermann et al. 2014). Subjects had to estimate the duration of temporal intervals of 500 ms defined by a tactile and a visual, masked stimulus. We observed a strong (~100 ms) underestimation of the temporal interval when the stimuli from both senses appeared to occur at the same position in space. In contrast, when the positions of the visual and tactile stimuli were spatially separate, interval perception was almost veridical. Temporal compression furthermore depended on the correspondence of probe features and was absent when the orientation of the tactile and visual probes was incongruent. An additional experiment revealed that temporal compression also occurs when objects were presented outside the attentional focus. In conclusion, these data support a role for spatiotemporal binding in temporal compression, which is at least in part selective for object features. PMID:27180810

  10. Linking species functional roles to their network roles.

    PubMed

    Coux, Camille; Rader, Romina; Bartomeus, Ignasi; Tylianakis, Jason M

    2016-07-01

    Species roles in ecological networks combine to generate their architecture, which contributes to their stability. Species trait diversity also affects ecosystem functioning and resilience, yet it remains unknown whether species' contributions to functional diversity relate to their network roles. Here, we use 21 empirical pollen transport networks to characterise this relationship. We found that, apart from a few abundant species, pollinators with original traits either had few interaction partners or interacted most frequently with a subset of these partners. This suggests that narrowing of interactions to a subset of the plant community accompanies pollinator niche specialisation, congruent with our hypothesised trade-off between having unique traits vs. being able to interact with many mutualist partners. Conversely, these effects were not detected in plants, potentially because key aspects of their flowering traits are conserved at a family level. Relating functional and network roles can provide further insight into mechanisms underlying ecosystem functioning. PMID:27169359

  11. The Role of Additional Pulses in Electropermeabilization Protocols

    PubMed Central

    Suárez, Cecilia; Soba, Alejandro; Maglietti, Felipe; Olaiz, Nahuel; Marshall, Guillermo

    2014-01-01

    Electropermeabilization (EP) based protocols such as those applied in medicine, food processing or environmental management, are well established and widely used. The applied voltage, as well as tissue electric conductivity, are of utmost importance for assessing final electropermeabilized area and thus EP effectiveness. Experimental results from literature report that, under certain EP protocols, consecutive pulses increase tissue electric conductivity and even the permeabilization amount. Here we introduce a theoretical model that takes into account this effect in the application of an EP-based protocol, and its validation with experimental measurements. The theoretical model describes the electric field distribution by a nonlinear Laplace equation with a variable conductivity coefficient depending on the electric field, the temperature and the quantity of pulses, and the Penne's Bioheat equation for temperature variations. In the experiments, a vegetable tissue model (potato slice) is used for measuring electric currents and tissue electropermeabilized area in different EP protocols. Experimental measurements show that, during sequential pulses and keeping constant the applied voltage, the electric current density and the blackened (electropermeabilized) area increase. This behavior can only be attributed to a rise in the electric conductivity due to a higher number of pulses. Accordingly, we present a theoretical modeling of an EP protocol that predicts correctly the increment in the electric current density observed experimentally during the addition of pulses. The model also demonstrates that the electric current increase is due to a rise in the electric conductivity, in turn induced by temperature and pulse number, with no significant changes in the electric field distribution. The EP model introduced, based on a novel formulation of the electric conductivity, leads to a more realistic description of the EP phenomenon, hopefully providing more accurate

  12. The role of additional pulses in electropermeabilization protocols.

    PubMed

    Suárez, Cecilia; Soba, Alejandro; Maglietti, Felipe; Olaiz, Nahuel; Marshall, Guillermo

    2014-01-01

    Electropermeabilization (EP) based protocols such as those applied in medicine, food processing or environmental management, are well established and widely used. The applied voltage, as well as tissue electric conductivity, are of utmost importance for assessing final electropermeabilized area and thus EP effectiveness. Experimental results from literature report that, under certain EP protocols, consecutive pulses increase tissue electric conductivity and even the permeabilization amount. Here we introduce a theoretical model that takes into account this effect in the application of an EP-based protocol, and its validation with experimental measurements. The theoretical model describes the electric field distribution by a nonlinear Laplace equation with a variable conductivity coefficient depending on the electric field, the temperature and the quantity of pulses, and the Penne's Bioheat equation for temperature variations. In the experiments, a vegetable tissue model (potato slice) is used for measuring electric currents and tissue electropermeabilized area in different EP protocols. Experimental measurements show that, during sequential pulses and keeping constant the applied voltage, the electric current density and the blackened (electropermeabilized) area increase. This behavior can only be attributed to a rise in the electric conductivity due to a higher number of pulses. Accordingly, we present a theoretical modeling of an EP protocol that predicts correctly the increment in the electric current density observed experimentally during the addition of pulses. The model also demonstrates that the electric current increase is due to a rise in the electric conductivity, in turn induced by temperature and pulse number, with no significant changes in the electric field distribution. The EP model introduced, based on a novel formulation of the electric conductivity, leads to a more realistic description of the EP phenomenon, hopefully providing more accurate

  13. Functions of Propolis as a natural feed additive in poultry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Propolis is a resinous hive product collected by honeybees from various sources of plants. Numerous scientific investigations have been focused on the biological activities of propolis and its functions as a health supplement in humans. It could have similar function in other animals, such as poultr...

  14. Mitochondrial phospholipids: role in mitochondrial function.

    PubMed

    Mejia, Edgard M; Hatch, Grant M

    2016-04-01

    Mitochondria are essential components of eukaryotic cells and are involved in a diverse set of cellular processes that include ATP production, cellular signalling, apoptosis and cell growth. These organelles are thought to have originated from a symbiotic relationship between prokaryotic cells in an effort to provide a bioenergetic jump and thus, the greater complexity observed in eukaryotes (Lane and Martin 2010). Mitochondrial processes are required not only for the maintenance of cellular homeostasis, but also allow cell to cell and tissue to tissue communication (Nunnari and Suomalainen 2012). Mitochondrial phospholipids are important components of this system. Phospholipids make up the characteristic outer and inner membranes that give mitochondria their shape. In addition, these membranes house sterols, sphingolipids and a wide variety of proteins. It is the phospholipids that also give rise to other characteristic mitochondrial structures such as cristae (formed from the invaginations of the inner mitochondrial membrane), the matrix (area within cristae) and the intermembrane space (IMS) which separates the outer mitochondrial membrane (OMM) and inner mitochondrial membrane (IMM). Phospholipids are the building blocks that make up these structures. However, the phospholipid composition of the OMM and IMM is unique in each membrane. Mitochondria are able to synthesize some of the phospholipids it requires, but the majority of cellular lipid biosynthesis takes place in the endoplasmic reticulum (ER) in conjunction with the Golgi apparatus (Fagone and Jackowski 2009). In this review, we will focus on the role that mitochondrial phospholipids play in specific cellular functions and discuss their biosynthesis, metabolism and transport as well as the differences between the OMM and IMM phospholipid composition. Finally, we will focus on the human diseases that result from disturbances to mitochondrial phospholipids and the current research being performed to help

  15. Additional developments regarding manifest dream structure and function.

    PubMed

    Wolowitz, H

    1998-06-01

    Detailed observation of manifest dream sequences indicated self-advocating occurrences facilitating the dreamer's self interests, opposed by self-adversarial interferences. Further examination of manifest dream syntactical structure additionally suggested a recurrent, four-step, algorithm for personal problem-solving within an interpersonal matrix consisting of the following cycle: (1) an opening scene setting the stage, (2) for the emergence of a self-concern, (3) which evokes a strategy to deal with dreamer's self-concern, (4) that eventuates in a consequence of the strategy. These steps repeat until the dream ends. Observing these manifest dream structural features, attributable to broadening past theorizing with "bottom-up" approaches, clarifies the dream's problem-solving process by providing an empirical, observable framework for dream interpretation and by contributing to their consensual validation. PMID:9656284

  16. Mutations in RIT1 cause Noonan syndrome - additional functional evidence and expanding the clinical phenotype.

    PubMed

    Koenighofer, M; Hung, C Y; McCauley, J L; Dallman, J; Back, E J; Mihalek, I; Gripp, K W; Sol-Church, K; Rusconi, P; Zhang, Z; Shi, G-X; Andres, D A; Bodamer, O A

    2016-03-01

    RASopathies are a clinically heterogeneous group of conditions caused by mutations in 1 of 16 proteins in the RAS-mitogen activated protein kinase (RAS-MAPK) pathway. Recently, mutations in RIT1 were identified as a novel cause for Noonan syndrome. Here we provide additional functional evidence for a causal role of RIT1 mutations and expand the associated phenotypic spectrum. We identified two de novo missense variants p.Met90Ile and p.Ala57Gly. Both variants resulted in increased MEK-ERK signaling compared to wild-type, underscoring gain-of-function as the primary functional mechanism. Introduction of p.Met90Ile and p.Ala57Gly into zebrafish embryos reproduced not only aspects of the human phenotype but also revealed abnormalities of eye development, emphasizing the importance of RIT1 for spatial and temporal organization of the growing organism. In addition, we observed severe lymphedema of the lower extremity and genitalia in one patient. We provide additional evidence for a causal relationship between pathogenic mutations in RIT1, increased RAS-MAPK/MEK-ERK signaling and the clinical phenotype. The mutant RIT1 protein may possess reduced GTPase activity or a diminished ability to interact with cellular GTPase activating proteins; however the precise mechanism remains unknown. The phenotypic spectrum is likely to expand and includes lymphedema of the lower extremities in addition to nuchal hygroma. PMID:25959749

  17. 21 CFR 14.142 - Functions of a color additive advisory committee.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Functions of a color additive advisory committee... SERVICES GENERAL PUBLIC HEARING BEFORE A PUBLIC ADVISORY COMMITTEE Color Additive Advisory Committees § 14.142 Functions of a color additive advisory committee. (a) A color additive advisory committee...

  18. 21 CFR 14.142 - Functions of a color additive advisory committee.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Functions of a color additive advisory committee... SERVICES GENERAL PUBLIC HEARING BEFORE A PUBLIC ADVISORY COMMITTEE Color Additive Advisory Committees § 14.142 Functions of a color additive advisory committee. (a) A color additive advisory committee...

  19. Role of developmental factors in hypothalamic function

    PubMed Central

    Biran, Jakob; Tahor, Maayan; Wircer, Einav; Levkowitz, Gil

    2015-01-01

    The hypothalamus is a brain region which regulates homeostasis by mediating endocrine, autonomic and behavioral functions. It is comprised of several nuclei containing distinct neuronal populations producing neuropeptides and neurotransmitters that regulate fundamental body functions including temperature and metabolic rate, thirst and hunger, sexual behavior and reproduction, circadian rhythm, and emotional responses. The identity, number and connectivity of these neuronal populations are established during the organism’s development and are of crucial importance for normal hypothalamic function. Studies have suggested that developmental abnormalities in specific hypothalamic circuits can lead to obesity, sleep disorders, anxiety, depression and autism. At the molecular level, the development of the hypothalamus is regulated by transcription factors (TF), secreted growth factors, neuropeptides and their receptors. Recent studies in zebrafish and mouse have demonstrated that some of these molecules maintain their expression in the adult brain and subsequently play a role in the physiological functions that are regulated by hypothalamic neurons. Here, we summarize the involvement of some of the key developmental factors in hypothalamic development and function by focusing on the mouse and zebrafish genetic model organisms. PMID:25954163

  20. Preparation and Characterization of Nanocomposite Polymer Membranes Containing Functionalized SnO2 Additives

    PubMed Central

    Scipioni, Roberto; Gazzoli, Delia; Teocoli, Francesca; Palumbo, Oriele; Paolone, Annalisa; Ibris, Neluta; Brutti, Sergio; Navarra, Maria Assunta

    2014-01-01

    In the research of new nanocomposite proton-conducting membranes, SnO2 ceramic powders with surface functionalization have been synthesized and adopted as additives in Nafion-based polymer systems. Different synthetic routes have been explored to obtain suitable, nanometer-sized sulphated tin oxide particles. Structural and morphological characteristics, as well as surface and bulk properties of the obtained oxide powders, have been determined by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) and Raman spectroscopies, N2 adsorption, and thermal gravimetric analysis (TGA). In addition, dynamic mechanical analysis (DMA), atomic force microscopy (AFM), thermal investigations, water uptake (WU) measurements, and ionic exchange capacity (IEC) tests have been used as characterization tools for the nanocomposite membranes. The nature of the tin oxide precursor, as well as the synthesis procedure, were found to play an important role in determining the morphology and the particle size distribution of the ceramic powder, this affecting the effective functionalization of the oxides. The incorporation of such particles, having sulphate groups on their surface, altered some peculiar properties of the resulting composite membrane, such as water content, thermo-mechanical, and morphological characteristics. PMID:24957125

  1. Enhancing the effectiveness of silicone thermal grease by the addition of functionalized carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Chen, Hongyuan; Wei, Hanxing; Chen, Minghai; Meng, Fancheng; Li, Hongbo; Li, Qingwen

    2013-10-01

    Functionalized carbon nanotubes (CNTs) were introduced into silicone grease to accompany the subsistent metallic oxide particles (micron-sized Al2O3, submicron-sized ZnO) with the aim of enhancing the thermal contact conductance of the composite grease as thermal interface materials (TIMs). The well-dispersed CNTs located among the metallic oxide particles to construct a three dimensional network structure and cooperated with them to form a highly efficient thermal transferring path. The functionalization of CNTs played a key role in achieving a good dispersion of CNTs in silicone grease matrix. The carboxylated CNTs were observed to show better dispersion in silicone grease and weaker reaction with oxide particles than pristine CNTs and amino-functionalized CNTs. Thus the thermal impedance of the silicone grease could be further decreased by 35% (as low as 0.18 cm2 K/W) with the addition of 2 wt.% carboxylated CNTs. Finally, such CNT-modified silicone grease was used to enhance the performance of high-power light emitting diode and showed the prospective applications in TIMs.

  2. The role of BMPs in endothelial cell function and dysfunction.

    PubMed

    Dyer, Laura A; Pi, Xinchun; Patterson, Cam

    2014-09-01

    The bone morphogenetic protein (BMP) family of proteins has a multitude of roles throughout the body. In embryonic development, BMPs promote endothelial specification and subsequent venous differentiation. The BMP pathway also plays important roles in the adult vascular endothelium, promoting angiogenesis and mediating shear and oxidative stress. The canonical BMP pathway functions through the Smad transcription factors; however, other intracellular signaling cascades can be activated, and receptor complexes beyond the traditional type I and type II receptors add additional layers of regulation. Dysregulated BMP signaling has been linked to vascular diseases including pulmonary hypertension and atherosclerosis. This review addresses recent advances in the roles of BMP signaling in the endothelium and how BMPs affect endothelial dysfunction and human disease. PMID:24908616

  3. Role of mitochondrial function in insulin resistance.

    PubMed

    Brands, Myrte; Verhoeven, Arthur J; Serlie, Mireille J

    2012-01-01

    The obesity pandemic increases the prevalence of type 2 diabetes (DM2).DM2 develops when pancreatic β-cells fail and cannot compensate for the decrease in insulin sensitivity. How excessive caloric intake and weight gain cause insulin resistance has not completely been elucidated.Skeletal muscle is responsible for a major part of insulin stimulated whole-body glucose disposal and, hence, plays an important role in the pathogenesis of insulin resistance.It has been hypothesized that skeletal muscle mitochondrial dysfunction is involved in the accumulation of intramyocellular lipid metabolites leading to lipotoxicity and insulin resistance. However, findings on skeletal muscle mitochondrial function in relation to insulin resistance in human subjects are inconclusive. Differences in mitochondrial activity can be the result of several factors, including a reduced mitochondrial density, differences in insulin stimulated mitochondrial respiration, lower energy demand or reduced skeletal muscle perfusion, besides an intrinsic mitochondrial defect. The inconclusive results may be explained by the use of different techniques and study populations. Also, mitochondrial capacity is in far excess to meet energy requirements and therefore it may be questioned whether a reduced mitochondrial capacity limits mitochondrial fatty acid oxidation. Whether reduced mitochondrial function is causally related to insulin resistance or rather a consequence of the sedentary lifestyle remains to be elucidated. PMID:22399424

  4. Pentraxins: structure, function, and role in inflammation.

    PubMed

    Du Clos, Terry W

    2013-01-01

    The pentraxins are an ancient family of proteins with a unique architecture found as far back in evolution as the Horseshoe crab. In humans the two members of this family are C-reactive protein and serum amyloid P. Pentraxins are defined by their sequence homology, their pentameric structure and their calcium-dependent binding to their ligands. Pentraxins function as soluble pattern recognition molecules and one of the earliest and most important roles for these proteins is host defense primarily against pathogenic bacteria. They function as opsonins for pathogens through activation of the complement pathway and through binding to Fc gamma receptors. Pentraxins also recognize membrane phospholipids and nuclear components exposed on or released by damaged cells. CRP has a specific interaction with small nuclear ribonucleoproteins whereas SAP is a major recognition molecule for DNA, two nuclear autoantigens. Studies in autoimmune and inflammatory disease models suggest that pentraxins interact with macrophage Fc receptors to regulate the inflammatory response. Because CRP is a strong acute phase reactant it is widely used as a marker of inflammation and infection. PMID:24167754

  5. Roles of additives and surface control in slurry atomization. Final project report

    SciTech Connect

    Tsai, S.C.

    1992-12-31

    This project studies the rheology and airblast atomization of micronized coal slurries. Its major objectives are (1) to promote further understanding of the mechanisms and the roles of additives in airblast atomization of coal water slurry (CWS), and (2) to investigate the impacts of coal particle surface properties and interparticle forces on CWS rheology. We have found that the flow behavior index (n) of a suspension (or slurry) is determined by the relative importance of the interparticle van der Waals attraction and the interparticle electrostatic repulsion. The interparticle attraction, measured by the Hamaker constant scaled to the thermal energy at 25{degrees}C (A/kT), causes particle aggregation, which breaks down at high shear rates, and thus leads to slurry pseudoplastic behavior (n< 1). At a constant particle volume fraction and surface charge density (qualitatively measured by the zeta potential in deionized water), n decreases linearly as A/kT increases. The relative viscosity of the pseudoplastic suspension with respect to that of the suspending liquid is found to be independent of particle density and correlate well with the particle Peclet number which equals the particle diffusional relaxation time multiplied by shear rate. Specifically, the relative viscosities of the pseudoplastic glycerol/water coal slurry and the ethylene glycol/glycerol sand slurry, at same volume fractions as well as similar particle size distributions and liquid viscosities, as functions of the particle Peclet number fall along the same line.

  6. Functional Roles of Bestrophins in Ocular Epithelia

    PubMed Central

    Marmorstein, Alan D.; Cross, Harold E.; Peachey, Neal S.

    2009-01-01

    There are four members of the bestrophin family of proteins in the human genome, of which two are known to be expressed in the eye. The gene BEST1 (formerly VMD2) which encodes the protein bestrophin-1 (Best1) was first identified in 1998. Mutations in this gene have now been associated with four clinically distinguishable human eye diseases, collectively referred to as “bestrophinopathies”. Over the last decade, laboratories have sought to understand how Best1 mutations could result in eye diseases that range in presentation from macular degeneration to nanophthalmos. The majority of our knowledge comes from studies that have sought to understand how Best1 mutations or dysfunction could induce the classical symptoms of the most common of these diseases: Best vitelliform macular dystrophy (BVMD). BVMD is a dominant trait that is characterized electrophysiologically by a diminished electrooculogram light peak with a normal clinical electroretinogram. This together with the localization of Best1 to the retinal pigment epithelium (RPE) basolateral plasma membrane and data from heterologous expression studies, have led to the proposal that Best1 generates the light peak, and that bestrophins are a family of Ca2+ activated Cl- channels (CaCCs). However, data from Best1 knock-out and knock-in mice, coupled with the recent discovery of a recessive bestrophinopathy suggest that Best1 does not generate the light peak. Recently Best2 was found to be expressed in non-pigmented epithelia in the ciliary body. However, aqueous dynamics in Best2 knock-out mice do not support a role for Best2 as a Cl- channel. Thus, the purported CaCC function of the bestrophins and how loss of this function relates to clinical disease needs to be reassessed. In this article, we examine data obtained from tissue-type and animal models and discuss the current state of bestrophin research, what roles Best1 and Best2 may play in ocular epithelia and ocular electrophysiology, and how perturbation

  7. Aegerolysins: Structure, function, and putative biological role

    PubMed Central

    Berne, Sabina; Lah, Ljerka; Sepčić, Kristina

    2009-01-01

    Aegerolysins, discovered in fungi, bacteria and plants, are highly similar proteins with interesting biological properties. Certain aegerolysins possess antitumoral, antiproliferative, and antibacterial activities. Further possible medicinal applications include their use in the prevention of atherosclerosis, or as vaccines. Additional biotechnological value of fungal aegerolysins lies in their involvement in development, which could improve cultivation of commercially important edible mushrooms. Besides, new insights on microheterogeneity of raft-like membrane domains could be gained by using aegerolysins as specific markers in cell and molecular biology. Although the exact function of aegerolysins in their producing organisms remains to be explained, they are biochemically well characterized all-β structured proteins sharing the following common features: low isoelectric points, similar molecular weights (15–17 kDa), and stability in a wide pH range. PMID:19309687

  8. Role of sulfite additives in wine induced asthma: single dose and cumulative dose studies

    PubMed Central

    Vally, H; Thompson, P

    2001-01-01

    BACKGROUND—Wine appears to be a significant trigger for asthma. Although sulfite additives have been implicated as a major cause of wine induced asthma, direct evidence is limited. Two studies were undertaken to assess sulfite reactivity in wine sensitive asthmatics. The first study assessed sensitivity to sulfites in wine using a single dose sulfited wine challenge protocol followed by a double blind, placebo controlled challenge. In the second study a cumulative dose sulfited wine challenge protocol was employed to establish if wine sensitive asthmatics as a group have an increased sensitivity to sulfites.
METHODS—In study 1, 24 asthmatic patients with a strong history of wine induced asthma were screened. Subjects showing positive responses to single blind high sulfite (300 ppm) wine challenge were rechallenged on separate days in a double blind, placebo controlled fashion with wines of varying sulfite levels to characterise their responses to these drinks. In study 2, wine sensitive asthmatic patients (n=12) and control asthmatics (n=6) were challenged cumulatively with wine containing increasing concentrations of sulfite in order to characterise further their sensitivity to sulfites in wine.
RESULTS—Four of the 24 self-reporting wine sensitive asthmatic patients were found to respond to sulfite additives in wine when challenged in a single dose fashion (study 1). In the double blind dose-response study all four had a significant fall in forced expiratory volume in one second (FEV1) (>15% from baseline) following exposure to wine containing 300 ppm sulfite, but did not respond to wines containing 20, 75 or 150 ppm sulfite. Responses were maximal at 5 minutes (mean (SD) maximal decline in FEV1 28.7 (13)%) and took 15-60 minutes to return to baseline levels. In the cumulative dose-response study (study 2) no significant difference was observed in any of the lung function parameters measured (FEV1, peak expiratory flow (PEF), mid phase forced expiratory

  9. Evidence for an association between gender-role identity and a measure of executive function.

    PubMed

    Norvilitis, Jill M; Reid, Howard M

    2002-02-01

    Two studies assessed the relation between gender role and executive function. In Study One (N = 234) analyses indicated that among college students executive function, assessed by the Coolidge and Griego scale, is related to masculine gender-role classification, measured by the Bem Sex-role Inventory. This relationship remained significant when biological sex was controlled. Further, factor analysis of the Bem Sex-role Inventory identified six components, three related to executive function. Two of these scales were associated with masculine characteristics, and the third was associated with the denial of several feminine items. Study Two (N = 53) further assessed the relationship among undergraduates through additional measures of executive functions and mood, in addition to the Bem Sex-role Inventory. In this study, executive functioning, as measured by the Coolidge and Griego scale, was again generally related to masculinity. Psychological well-being was not related to gender identity or executive functioning. PMID:11899009

  10. Roles for major histocompatibility complex glycosylation in immune function

    PubMed Central

    Ryan, Sean O.

    2013-01-01

    The major histocompatibility complex (MHC) glycoprotein family, also referred to as human leukocyte antigens, present endogenous and exogenous antigens to T lymphocytes for recognition and response. These molecules play a central role in enabling the immune system to distinguish self from non-self, which is the basis for protective immunity against pathogenic infections and disease while at the same time representing a serious obstacle for tissue transplantation. All known MHC family members, like the majority of secreted, cell surface, and other immune-related molecules, carry asparagine (N)-linked glycans. The immune system has evolved increasing complexity in higher-order organisms along with a more complex pattern of protein glycosylation, a relationship that may contribute to immune function beyond the early protein quality control events in the endoplasmic reticulum that are commonly known. The broad MHC family maintains peptide sequence motifs for glycosylation at sites that are highly conserved across evolution, suggesting importance, yet functional roles for these glycans remain largely elusive. In this review, we will summarize what is known about MHC glycosylation and provide new insight for additional functional roles for this glycoprotein modification in mediating immune responses. PMID:22461020

  11. Functional roles of non-coding Y RNAs

    PubMed Central

    Kowalski, Madzia P.; Krude, Torsten

    2015-01-01

    Non-coding RNAs are involved in a multitude of cellular processes but the biochemical function of many small non-coding RNAs remains unclear. The family of small non-coding Y RNAs is conserved in vertebrates and related RNAs are present in some prokaryotic species. Y RNAs are also homologous to the newly identified family of non-coding stem-bulge RNAs (sbRNAs) in nematodes, for which potential physiological functions are only now emerging. Y RNAs are essential for the initiation of chromosomal DNA replication in vertebrates and, when bound to the Ro60 protein, they are involved in RNA stability and cellular responses to stress in several eukaryotic and prokaryotic species. Additionally, short fragments of Y RNAs have recently been identified as abundant components in the blood and tissues of humans and other mammals, with potential diagnostic value. While the number of functional roles of Y RNAs is growing, it is becoming increasingly clear that the conserved structural domains of Y RNAs are essential for distinct cellular functions. Here, we review the biochemical functions associated with these structural RNA domains, as well as the functional conservation of Y RNAs in different species. The existing biochemical and structural evidence supports a domain model for these small non-coding RNAs that has direct implications for the modular evolution of functional non-coding RNAs. PMID:26159929

  12. Versatile Role of Solvent Additive for Tailoring Morphology in Polymer Solar Cells for Efficient Charge Transport.

    PubMed

    Khatiwada, Devendra; Venkatesan, Swaminathan; Ngo, Evan C; Qiao, Qiquan

    2015-09-01

    In this work role of solvent additive namely 1,8 diiodoctane (DIO) on the nanoscale morphology and its relation with the charge transport of poly(diketopyrrolopyrrole-terthiophene) (PDPP3T):PCBM solar cells has been investigated. Addition of DIO led to enhanced structural ordering as observed from optical measurements. Photovoltaic devices processed with DIO additive showed improved efficiencies due to significant enhancement in short circuit current density. Atomic force microscopy (AFM) and Kelvin probe force microscopy (KPFM) images showed that DIO led to finer phase segregation that gave rise to better photovoltaic performance in additive processed active layers. Photoinduced current extraction by linearly increasing voltage (P-CELIV) measurements on PDPP3T:PCBM solar cells revealed higher mobility and extracted charge carrier density for DIO processed devices. PMID:26716280

  13. Role of additives in wood plastic composite of water soluble monomer

    NASA Astrophysics Data System (ADS)

    Ali, K. M. Idriss; Khan, Mubarak A.; Husain, M. M.

    1994-10-01

    Wood plastic composites are prepared under radiation of 60Co gamma source with simul, a low grade wood of Bangladesh using a water soluble monomer acrylamide (AM) mixed with a swelling solvent methanol, water or methanol/water (1:1) at different compositions in the presence of a number of additives and co-additives such as NVP ( N-vinylpyrrolidone), TPGDA (tripropylene glycol diacrylate), TMPTA (trimethylol propane triacrylate), sulfuric acid, urea and copper sulfate. Polymer loading (PL) and tensile strength (TS) of the composites are measured. The role of these additives on the composites is also discussed. It is observed that nitrogen-atom containing-materials like urea, NVP and AM produce composites with the highest mechanical strength, and incorporation of copper into this system provides additional property of protection and preservation of the composites against attacks by insects and microbes.

  14. Switch of SpnR function from activating to inhibiting quorum sensing by its exogenous addition.

    PubMed

    Takayama, Yuriko; Kato, Norihiro

    2016-09-01

    The opportunistic human pathogen Serratia marcescens AS-1 produces the N-hexanoylhomoserine lactone (C6HSL) receptor SpnR, a homologue of LuxR from Vibrio fischeri, which activates pig clusters to produce the antibacterial prodigiosin. In this study, we attempted to artificially regulate quorum sensing (QS) by changing the role of SpnR in N-acylhomoserine lactone (AHL)-mediated QS. SpnR was obtained as a fusion protein tagged with maltose-binding protein (MBP) from overexpression in Escherichia coli, and its specific affinity to C6HSL was demonstrated by quartz crystal microbalance analysis and AHL-bioassay with Chromobacterium violaceum CV026. Prodigiosin production was effectively inhibited by externally added MBP-SpnR in both wild-type AS-1 and the AHL synthase-defective mutant AS-1(ΔspnI). For the mutant, the induced amount of prodigiosin was drastically reduced to approximately 4% with the addition of 18 μM MBP-SpnR to the liquid medium, indicating 81% trapping of C6HSL. A system for inhibiting QS can be constructed by adding exogenous AHL receptor to the culture broth to keep the concentration of free AHL low, whereas intracellular SpnR naturally functions as the activator in response to QS. PMID:27387237

  15. Preparation and ageing-resistant properties of polyester composites modified with functional nanoscale additives

    NASA Astrophysics Data System (ADS)

    Guo, Gang; Shi, Qiwu; Luo, Yanbing; Fan, Rangrang; Zhou, Liangxue; Qian, Zhiyong; Yu, Jie

    2014-05-01

    This study investigated ageing-resistant properties of carboxyl-terminated polyester (polyethylene glycol terephthalate) composites modified with nanoscale titanium dioxide particles (nano-TiO2). The nano-TiO2 was pretreated by a dry coating method, with aluminate coupling agent as a functional grafting additive. The agglomeration resistance was evaluated, which exhibited significant improvement for the modified nanoparticles. Then, the effects of the modified nano-TiO2 on the crosslinking and ageing-resistant properties of the composites were studied. With a real-time Fourier transform infrared (FT-IR) measurement, the nano-TiO2 displayed promoting effect on the crosslinking of polyester resin with triglycidyl isocyanurate (TGIC) as crosslinking agent. Moreover, the gloss retention, colour aberration and the surface morphologies of the composites during accelerated UV ageing (1500 hours) were investigated. The results demonstrated much less degree of ageing degradation for the nanocomposites, indicating an important role of the nano-TiO2 in improving the ageing-resistant properties of synthetic polymer composites.

  16. Preparation and ageing-resistant properties of polyester composites modified with functional nanoscale additives.

    PubMed

    Guo, Gang; Shi, Qiwu; Luo, Yanbing; Fan, Rangrang; Zhou, Liangxue; Qian, Zhiyong; Yu, Jie

    2014-01-01

    This study investigated ageing-resistant properties of carboxyl-terminated polyester (polyethylene glycol terephthalate) composites modified with nanoscale titanium dioxide particles (nano-TiO2). The nano-TiO2 was pretreated by a dry coating method, with aluminate coupling agent as a functional grafting additive. The agglomeration resistance was evaluated, which exhibited significant improvement for the modified nanoparticles. Then, the effects of the modified nano-TiO2 on the crosslinking and ageing-resistant properties of the composites were studied. With a real-time Fourier transform infrared (FT-IR) measurement, the nano-TiO2 displayed promoting effect on the crosslinking of polyester resin with triglycidyl isocyanurate (TGIC) as crosslinking agent. Moreover, the gloss retention, colour aberration and the surface morphologies of the composites during accelerated UV ageing (1500 hours) were investigated. The results demonstrated much less degree of ageing degradation for the nanocomposites, indicating an important role of the nano-TiO2 in improving the ageing-resistant properties of synthetic polymer composites. PMID:24872802

  17. Functional neuroanatomy of developmental dyslexia: the role of orthographic depth

    PubMed Central

    Richlan, Fabio

    2014-01-01

    Orthographic depth (OD) (i.e., the complexity, consistency, or transparency of grapheme-phoneme correspondences in written alphabetic language) plays an important role in the acquisition of reading skills. Correspondingly, developmental dyslexia is characterized by different behavioral manifestations across languages varying in OD. This review focuses on the question of whether these different behavioral manifestations are associated with different functional neuroanatomical manifestations. It provides a review and critique of cross-linguistic brain imaging studies of developmental dyslexia. In addition, it includes an analysis of state-of-the-art functional neuroanatomical models of developmental dyslexia together with orthography-specific predictions derived from these models. These predictions should be tested in future brain imaging studies of typical and atypical reading in order to refine the current neurobiological understanding of developmental dyslexia, especially with respect to orthography-specific and universal aspects. PMID:24904383

  18. Asymmetric Catalytic Enantio- and Diastereoselective Boron Conjugate Addition Reactions of α-Functionalized α,β-Unsaturated Carbonyl Substrates.

    PubMed

    Xie, Jian-Bo; Lin, Siqi; Qiao, Shuo; Li, Guigen

    2016-08-01

    An efficient catalytic system has been established for the asymmetric boron conjugate addition of B2pin2 onto α-functionalized (involving C, N, O, and Cl) α,β-unsaturated carbonyls under mild, neutral conditions involving Cu[(S)-(R)-ppfa]Cl, AgNTf2, and alcohols. The dual additives of AgNTf2 and alcohols were found to play crucial roles for achieving high catalytic activity and enantio- and diastereoselectivity (up to 98% ee and 70:1 dr). PMID:27434500

  19. Steroid receptor RNA activator: Biologic function and role in disease.

    PubMed

    Liu, Chan; Wu, Hong-Tao; Zhu, Neng; Shi, Ya-Ning; Liu, Zheng; Ao, Bao-Xue; Liao, Duan-Fang; Zheng, Xi-Long; Qin, Li

    2016-08-01

    Steroid receptor RNA activator (SRA) is a type of long noncoding RNA (lncRNA) which coordinates the functions of various transcription factors, enhances steroid receptor-dependent gene expression, and also serves as a distinct scaffold. The novel, profound and expanded roles of SRA are emerging in critical aspects of coactivation of nuclear receptors (NRs). As a nuclear receptor coactivator, SRA can coactivate androgen receptor (AR), estrogen receptor α (ERα), ERβ, progesterone receptor (PR), glucocorticoid receptor (GR), thyroid hormone receptor and retinoic acid receptor (RAR). Although SRA is one of the least well-understood molecules, increasing studies have revealed that SRA plays a key role in both biological processes, such as myogenesis and steroidogenesis, and pathological changes, including obesity, cardiomyopathy, and tumorigenesis. Furthermore, the SRA-related signaling pathways, such as the mitogen-activated protein kinase (p38 MAPK), Notch and tumor necrosis factor α (TNFα) pathways, play critical roles in the pathogenesis of estrogen-dependent breast cancers. In addition, the most recent data demonstrates that SRA expression may serve as a new prognostic marker in patients with ER-positive breast cancer. Thus, elucidating the molecular mechanisms underlying SRA-mediated functions is important to develop proper novel strategies to target SRA in the diagnosis and treatment of human diseases. PMID:27282881

  20. The role of laminins in basement membrane function

    PubMed Central

    AUMAILLEY, MONIQUE; SMYTH, NEIL

    1998-01-01

    Laminins are a family of multifunctional macromolecules, ubiquitous in basement membranes, and represent the most abundant structural noncollagenous glycoproteins of these highly specialised extracellular matrices. Their discovery started with the difficult task of isolating molecules produced by cultivated cells or extracted from tissues. The development of molecular biology techniques has facilitated and accelerated the identification and the characterisation of new laminin variants making it feasible to identify full-length polypeptides which have not been purified. Further, genetically engineered laminin fragments can be generated for studies of their structure-function relationship, permitting the demonstration that laminins are involved in multiple interactions with themselves, with other components of the basal lamina, and with cells. It endows laminins with a central role in the formation, the architecture, and the stability of basement membranes. In addition, laminins may both separate and connect different tissues, i.e. the parenchymal and the interstitial connective tissues. Laminins also provide adjacent cells with a mechanical scaffold and biological information either directly by interacting with cell surface components, or indirectly by trapping growth factors. In doing so they trigger and control cellular functions. Recently, the structural and biological diversity of the laminins has started to be elucidated by gene targeting and by the identification of laminin defects in acquired or inherited human diseases. The consequent phenotypes highlight the pivotal role of laminins in determining heterogeneity in basement membrane functions. PMID:9758133

  1. The role of estradiol in male reproductive function.

    PubMed

    Schulster, Michael; Bernie, Aaron M; Ramasamy, Ranjith

    2016-01-01

    Traditionally, testosterone and estrogen have been considered to be male and female sex hormones, respectively. However, estradiol, the predominant form of estrogen, also plays a critical role in male sexual function. Estradiol in men is essential for modulating libido, erectile function, and spermatogenesis. Estrogen receptors, as well as aromatase, the enzyme that converts testosterone to estrogen, are abundant in brain, penis, and testis, organs important for sexual function. In the brain, estradiol synthesis is increased in areas related to sexual arousal. In addition, in the penis, estrogen receptors are found throughout the corpus cavernosum with high concentration around neurovascular bundles. Low testosterone and elevated estrogen increase the incidence of erectile dysfunction independently of one another. In the testes, spermatogenesis is modulated at every level by estrogen, starting with the hypothalamus-pituitary-gonadal axis, followed by the Leydig, Sertoli, and germ cells, and finishing with the ductal epithelium, epididymis, and mature sperm. Regulation of testicular cells by estradiol shows both an inhibitory and a stimulatory influence, indicating an intricate symphony of dose-dependent and temporally sensitive modulation. Our goal in this review is to elucidate the overall contribution of estradiol to male sexual function by looking at the hormone's effects on erectile function, spermatogenesis, and libido. PMID:26908066

  2. The role of estradiol in male reproductive function

    PubMed Central

    Schulster, Michael; Bernie, Aaron M; Ramasamy, Ranjith

    2016-01-01

    Traditionally, testosterone and estrogen have been considered to be male and female sex hormones, respectively. However, estradiol, the predominant form of estrogen, also plays a critical role in male sexual function. Estradiol in men is essential for modulating libido, erectile function, and spermatogenesis. Estrogen receptors, as well as aromatase, the enzyme that converts testosterone to estrogen, are abundant in brain, penis, and testis, organs important for sexual function. In the brain, estradiol synthesis is increased in areas related to sexual arousal. In addition, in the penis, estrogen receptors are found throughout the corpus cavernosum with high concentration around neurovascular bundles. Low testosterone and elevated estrogen increase the incidence of erectile dysfunction independently of one another. In the testes, spermatogenesis is modulated at every level by estrogen, starting with the hypothalamus-pituitary-gonadal axis, followed by the Leydig, Sertoli, and germ cells, and finishing with the ductal epithelium, epididymis, and mature sperm. Regulation of testicular cells by estradiol shows both an inhibitory and a stimulatory influence, indicating an intricate symphony of dose-dependent and temporally sensitive modulation. Our goal in this review is to elucidate the overall contribution of estradiol to male sexual function by looking at the hormone's effects on erectile function, spermatogenesis, and libido. PMID:26908066

  3. Academic and Social Achievement Goals: Their Additive, Interactive, and Specialized Effects on School Functioning

    ERIC Educational Resources Information Center

    Liem, Gregory Arief D.

    2016-01-01

    Background: Students' pursuit of academic and social goals has implications for school functioning. However, studies on academic and social achievement goals have been relatively independent and mainly conducted with students in culturally Western settings. Aims: Guided by multiple-goal perspectives, this study examined the role of academic and…

  4. Atomic electron affinities and the role of symmetry between electron addition and subtraction in a corrected Koopmans approach.

    PubMed

    Teale, A M; De Proft, F; Geerlings, P; Tozer, D J

    2014-07-28

    The essential aspects of zero-temperature grand-canonical ensemble density-functional theory are reviewed in the context of spin-density-functional theory and are used to highlight the assumption of symmetry between electron addition and subtraction that underlies the corrected Koopmans approach of Tozer and De Proft (TDP) for computing electron affinities. The issue of symmetry is then investigated in a systematic study of atomic electron affinities, comparing TDP affinities with those from a conventional Koopmans evaluation and electronic energy differences. Although it cannot compete with affinities determined from energy differences, the TDP expression yields results that are a significant improvement over those from the conventional Koopmans expression. Key insight into the results from both expressions is provided by an analysis of plots of the electronic energy as a function of the number of electrons, which highlight the extent of symmetry between addition and subtraction. The accuracy of the TDP affinities is closely related to the nature of the orbitals involved in the electron addition and subtraction, being particularly poor in cases where there is a change in principal quantum number, but relatively accurate within a single manifold of orbitals. The analysis is then extended to a consideration of the ground state Mulliken electronegativity and chemical hardness. The findings further emphasize the key role of symmetry in determining the quality of the results. PMID:24406854

  5. Tailoring magnetic properties in arrays of pulse-electrodeposited Co nanowires: The role of Cu additive

    NASA Astrophysics Data System (ADS)

    Esmaeili, A.; Almasi Kashi, M.; Ramazani, A.; Montazer, A. H.

    2016-01-01

    In this study, we aim to report the role of Cu additive in arrays of pulse-electrodeposited Co nanowires (NWs) with diameters from 30 to 75 nm, embedded in porous aluminum oxide templates. This features the role of Cu additive in composition and crystalline characteristics as well as in the magnetic properties of Co NWs. Increasing the duration of off-time between pulses during the electrodeposition of Co NWs made it possible to increase the amount of Cu content, so that Co-rich CoCu NWs were obtained. The parallel coercivity and squareness values increased up to 1500 Oe and 0.8 for 30 nm diameter Co94Cu6 NWs, starting from 500 Oe and 0.3 for pure Co NWs. On the other hand, although there was a substantial difference between the crystalline characteristics of 75 nm diameter pure Co and CoCu NWs, no considerable change in their magnetic properties was observed using hysteresis loop measurements. In this respect, the first-order reversal curve (FORC) analysis revealed strong inter-wire magnetostatic interactions for the CoCu NWs. Moreover, we studied the effect of thermal annealing, which resulted in an increase in the coercivity of CoCu NWs with different diameters up to 15%. As a result, the addition of small amount of Cu provides an alternative approach to tailoring the magnetic properties of Co NWs.

  6. Narcissism, Sex Roles, and Self-Functioning.

    ERIC Educational Resources Information Center

    Watson, P. J.; And Others

    1987-01-01

    Examines the relationship between gender, sex role, and narcissism. Data indicated that males and masculine individuals were not higher in their levels of maladaptive narcissism, that an adjusted narcissism was more obvious in males and in masculine subjects, and that femininity appeared to inhibit the display of an unhealthy exploitative…

  7. Functional Role of FcγRIIB in the Regulation of Mesenchymal Stem Cell Function

    PubMed Central

    Zhu, Tianyi; Chen, Ruohua; Li, Zeng; Tian, Jun; Deng, Changwen; Zhang, Xingxing; Zhang, Koudong; Tong, Linrong; Yu, Yizhi; Bai, Chong

    2016-01-01

    Mesenchymal stem cells (MSCs) derived from bone marrow are plural-potent stem cells with immune regulatory functions. We aimed to evaluate role of FcγRIIB in the regulation of bone marrow-derived MSC function. MSCs were prepared from mouse bone marrow derived from wild-type (WT) or FcγRIIB-deficient (FcγRIIB-/-) mice. MSCs were co-cultured with bone marrow-derived dendritic cells (BMDCs), and BMDC maturation and function were evaluated by flow cytometric analysis and carboxyfluorescein succinimidyl ester-labeled OT-II T-cell addition. An acute asthma model was established by aeresol ovalbumin challenge in mice. Mice received WT or FcγRIIB-/- MSC therapy. Lung function was evaluated by histological examination and cytokine production measurement. mRNA and protein expression levels of target genes were examined by real-time quantitative polymerase chain reactionor western blotting. We found that MSCs derived from bone marrow exhibit a high level of FcγRIIB expression. FcγRIIB deficiency impaired the suppressive function of MSCs, as FcγRIIB deficiency efficiently reversed the inhibitory effect of MSCs on BMDC maturation and function. Additionally, FcγRIIB-/-MSCs were less potent at suppressing asthma in model mice, possibly through reduced expression of Smad2, Smad3, Cox-2, and prostaglandin E2 in FcγRIIB-/-MSCs. FcγRIIB might play an essential role in regulating the inhibitory effects of MSCs derived from bone marrow. PMID:26941575

  8. Functional Role of FcγRIIB in the Regulation of Mesenchymal Stem Cell Function.

    PubMed

    Zhu, Tianyi; Chen, Ruohua; Li, Zeng; Tian, Jun; Deng, Changwen; Zhang, Xingxing; Zhang, Koudong; Tong, Linrong; Yu, Yizhi; Bai, Chong

    2016-01-01

    Mesenchymal stem cells (MSCs) derived from bone marrow are plural-potent stem cells with immune regulatory functions. We aimed to evaluate role of FcγRIIB in the regulation of bone marrow-derived MSC function. MSCs were prepared from mouse bone marrow derived from wild-type (WT) or FcγRIIB-deficient (FcγRIIB-/-) mice. MSCs were co-cultured with bone marrow-derived dendritic cells (BMDCs), and BMDC maturation and function were evaluated by flow cytometric analysis and carboxyfluorescein succinimidyl ester-labeled OT-II T-cell addition. An acute asthma model was established by aeresol ovalbumin challenge in mice. Mice received WT or FcγRIIB-/- MSC therapy. Lung function was evaluated by histological examination and cytokine production measurement. mRNA and protein expression levels of target genes were examined by real-time quantitative polymerase chain reactionor western blotting. We found that MSCs derived from bone marrow exhibit a high level of FcγRIIB expression. FcγRIIB deficiency impaired the suppressive function of MSCs, as FcγRIIB deficiency efficiently reversed the inhibitory effect of MSCs on BMDC maturation and function. Additionally, FcγRIIB-/-MSCs were less potent at suppressing asthma in model mice, possibly through reduced expression of Smad2, Smad3, Cox-2, and prostaglandin E2 in FcγRIIB-/-MSCs. FcγRIIB might play an essential role in regulating the inhibitory effects of MSCs derived from bone marrow. PMID:26941575

  9. Brain and Retinal Pericytes: Origin, Function and Role.

    PubMed

    Trost, Andrea; Lange, Simona; Schroedl, Falk; Bruckner, Daniela; Motloch, Karolina A; Bogner, Barbara; Kaser-Eichberger, Alexandra; Strohmaier, Clemens; Runge, Christian; Aigner, Ludwig; Rivera, Francisco J; Reitsamer, Herbert A

    2016-01-01

    Pericytes are specialized mural cells located at the abluminal surface of capillary blood vessels, embedded within the basement membrane. In the vascular network these multifunctional cells fulfil diverse functions, which are indispensable for proper homoeostasis. They serve as microvascular stabilizers, are potential regulators of microvascular blood flow and have a central role in angiogenesis, as they for example regulate endothelial cell proliferation. Furthermore, pericytes, as part of the neurovascular unit, are a major component of the blood-retina/brain barrier. CNS pericytes are a heterogenic cell population derived from mesodermal and neuro-ectodermal germ layers acting as modulators of stromal and niche environmental properties. In addition, they display multipotent differentiation potential making them an intriguing target for regenerative therapies. Pericyte-deficiencies can be cause or consequence of many kinds of diseases. In diabetes, for instance, pericyte-loss is a severe pathological process in diabetic retinopathy (DR) with detrimental consequences for eye sight in millions of patients. In this review, we provide an overview of our current understanding of CNS pericyte origin and function, with a special focus on the retina in the healthy and diseased. Finally, we highlight the role of pericytes in de- and regenerative processes. PMID:26869887

  10. Brain and Retinal Pericytes: Origin, Function and Role

    PubMed Central

    Trost, Andrea; Lange, Simona; Schroedl, Falk; Bruckner, Daniela; Motloch, Karolina A.; Bogner, Barbara; Kaser-Eichberger, Alexandra; Strohmaier, Clemens; Runge, Christian; Aigner, Ludwig; Rivera, Francisco J.; Reitsamer, Herbert A.

    2016-01-01

    Pericytes are specialized mural cells located at the abluminal surface of capillary blood vessels, embedded within the basement membrane. In the vascular network these multifunctional cells fulfil diverse functions, which are indispensable for proper homoeostasis. They serve as microvascular stabilizers, are potential regulators of microvascular blood flow and have a central role in angiogenesis, as they for example regulate endothelial cell proliferation. Furthermore, pericytes, as part of the neurovascular unit, are a major component of the blood-retina/brain barrier. CNS pericytes are a heterogenic cell population derived from mesodermal and neuro-ectodermal germ layers acting as modulators of stromal and niche environmental properties. In addition, they display multipotent differentiation potential making them an intriguing target for regenerative therapies. Pericyte-deficiencies can be cause or consequence of many kinds of diseases. In diabetes, for instance, pericyte-loss is a severe pathological process in diabetic retinopathy (DR) with detrimental consequences for eye sight in millions of patients. In this review, we provide an overview of our current understanding of CNS pericyte origin and function, with a special focus on the retina in the healthy and diseased. Finally, we highlight the role of pericytes in de- and regenerative processes. PMID:26869887

  11. Functional Role of G9a Histone Methyltransferase in Cancer

    PubMed Central

    Casciello, Francesco; Windloch, Karolina; Gannon, Frank; Lee, Jason S.

    2015-01-01

    Post-translational modifications of DNA and histones are epigenetic mechanisms, which affect the chromatin structure, ultimately leading to gene expression changes. A number of different epigenetic enzymes are actively involved in the addition or the removal of various covalent modifications, which include acetylation, methylation, phosphorylation, ubiquitination, and sumoylation. Deregulation of these processes is a hallmark of cancer. For instance, G9a, a histone methyltransferase responsible for histone H3 lysine 9 (H3K9) mono- and dimethylation, has been observed to be upregulated in different types of cancer and its overexpression has been associated with poor prognosis. Key roles played by these enzymes in various diseases have led to the hypothesis that these molecules represent valuable targets for future therapies. Several small molecule inhibitors have been developed to specifically block the epigenetic activity of these enzymes, representing promising therapeutic tools in the treatment of human malignancies, such as cancer. In this review, the role of one of these epigenetic enzymes, G9a, is discussed, focusing on its functional role in regulating gene expression as well as its implications in cancer initiation and progression. We also discuss important findings from recent studies using epigenetic inhibitors in cell systems in vitro as well as experimental tumor growth and metastasis assays in vivo. PMID:26441991

  12. a Study on the Role of Sintering Additives for Fabrication of sic Ceramic

    NASA Astrophysics Data System (ADS)

    Yoon, Han Ki; Lee, Young Ju; Cho, Ho Jun; Kim, Tae Gyu

    Silicon carbide (SiC) materials have been extensively studied for high temperature components in advanced energy system and advanced gas turbine. The SiC ceramics have been fabricated by a NITE (Nano Infiltration Transient Eutectic Phase) Process, using Nano-SiC powder. The sintering additives used for forming liquid phase under sintering process, used the sintering additives ratios were an Al2O3-Y2O3 system or add SiO2 contents. A major R&D focus for the SiC ceramics is the production to obtain high purity SiC ceramics. In this study, we investigated roles of the sintering additives(Al2O3:Y2O3) to fabrication of the SiC ceramics. The effects of SiO2 contents and density properties of the SiC ceramics were also investigated. To investigate the effects of SiO2, Al2O3/Y2O3 composition were fixed and then SiO2 ratios were changed as several kinds, and to confirm the effects of sintering additives ratios (Al2O3:Y2O3) they were changed between 4:6 and 6:4 in x wt.%.

  13. Functional roles of low calorie sweeteners on gut function.

    PubMed

    Meyer-Gerspach, A C; Wölnerhanssen, B; Beglinger, C

    2016-10-01

    This short review summarizes the effects of low calorie sweeteners (fructose, non-nutritive low calorie sweeteners) on gut functions focusing on the gut sweet taste receptor system. The effects of these molecules on secretion of gut peptides associated with glycemic homeostasis and appetite regulation is reviewed as well as effects on gastric emptying and glucose absorption. PMID:26861179

  14. Brief Report: Additive and Subtractive Counterfactual Reasoning of Children with High-Functioning Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Begeer, Sander; Terwogt, Mark Meerum; Lunenburg, Patty; Stegge, Hedy

    2009-01-01

    The development of additive ("If only I had done...") and subtractive ("If only I had not done....") counterfactual reasoning was examined in children with High Functioning Autism Spectrum Disorders (HFASD) (n = 72) and typically developing controls (n = 71), aged 6-12 years. Children were presented four stories where they could generate…

  15. The Role of Attachment Functions in Psychotherapy

    PubMed Central

    Spiegel, Jeremy; Severino, Sally K.; Morrison, Nancy K.

    2000-01-01

    The authors propose to clarify concepts of emotional attunement and failures of attunement in early development derived from theoretical and clinical work (Kohut) and infant psychiatry (Stern). Early attunement failures are experienced as shameful by the infant/child, and without repair they form a nidus for later destructive adult interpersonal relationships, “social blindness,” and depression. The authors present a case illustrating these ideas. The role of empathic attunement experienced in the unique setting/structure of psychotherapy emerges as the single critical variable for a successful outcome. PMID:10608906

  16. Medulloblastoma Exosome Proteomics Yield Functional Roles for Extracellular Vesicles

    PubMed Central

    Epple, Laura M.; Griffiths, Steve G.; Dechkovskaia, Anjelika M.; Dusto, Nathaniel L.; White, Jason; Ouellette, Rodney J.; Anchordoquy, Thomas J.; Bemis, Lynne T.; Graner, Michael W.

    2012-01-01

    Medulloblastomas are the most prevalent malignant pediatric brain tumors. Survival for these patients has remained largely the same for approximately 20 years, and our therapies for these cancers cause significant health, cognitive, behavioral and developmental sequelae for those who survive the tumor and their treatments. We obviously need a better understanding of the biology of these tumors, particularly with regard to their migratory/invasive behaviors, their proliferative propensity, and their abilities to deflect immune responses. Exosomes, virus-sized membrane vesicles released extracellularly from cells after formation in, and transit thru, the endosomal pathway, may play roles in medulloblastoma pathogenesis but are as yet unstudied in this disease. Here we characterized exosomes from a medulloblastoma cell line with biochemical and proteomic analyses, and included characterization of patient serum exosomes. Further scrutiny of the proteomic data suggested functional properties of the exosomes that are relevant to medulloblastoma tumor biology, including their roles as proliferation stimulants, their activities as attractants for tumor cell migration, and their immune modulatory impacts on lymphocytes. Aspects of this held true for exosomes from other medulloblastoma cell lines as well. Additionally, pathway analyses suggested a possible role for the transcription factor hepatocyte nuclear factor 4 alpha (HNF4A); however, inhibition of the protein’s activity actually increased D283MED cell proliferation/clonogenecity, suggesting that HNF4A may act as a tumor suppressor in this cell line. Our work demonstrates that relevant functional properties of exosomes may be derived from appropriate proteomic analyses, which translate into mechanisms of tumor pathophysiology harbored in these extracellular vesicles. PMID:22848702

  17. Modulatory role of the ovarian function in neuroimmunoendocrine axis activity.

    PubMed

    Perelló, Mario; Giovambattista, Andrés; Castrogiovanni, Daniel; Gaillard, Rolf C; Spinedi, Eduardo

    2011-01-01

    The aim of this study was to evaluate the effect of ovariectomy on the acute-phase response of inflammatory stress. Ex vivo adrenocortical, peripheral mononuclear cell (PMNC) and adipocyte activities were studied in intact and ovariectomized mice. Endotoxemia was mimicked by intraperitoneal administration of bacterial lipopolysaccharide (LPS; 25 mg per mouse) to sham-operated and 21-day ovariectomized mice. Circulating corticosterone, tumor necrosis factor-α (TNFα) and leptin concentrations were monitored before and 30-120 min after the administration of LPS. Additionally, in vitro experiments were performed with isolated corticoadrenal cells, PMNCs and omental adipocytes from sham-operated and ovariectomized mice incubated with specific secretagogues. The results indicate that while ovariectomy enhanced TNFα secretion after in vivo administration of LPS, it reduced corticoadrenal response and abrogated LPS-elicited leptin secretion into the circulation. While the corticoadrenal sensitivity to ACTH stimulation was reduced by ovariectomy, the LPS-induced PMNC response was not affected. Exogenous leptin enhanced baseline PMNC function regardless of surgery. Finally, ovariectomy drastically reduced in vitro adipocyte functionality. Our data support the notion that ovariectomy modified neuroendocrine-immune-adipocyte axis function and strongly suggest that ovarian activity could play a pivotal role in the development of an adequate immune defense mechanism after injury. PMID:20606490

  18. The Role of Cocoa as a Cigarette Additive: Opportunities for Product Regulation

    PubMed Central

    Kennedy, Ryan David; Connolly, Gregory N.

    2014-01-01

    Introduction: The 2009 Family Smoking Prevention and Tobacco Control Act prohibited the use of characterizing flavors in cigarettes; however, some of these flavors are still used in cigarettes at varying levels. We reviewed tobacco industry internal documents to investigate the role of one of these flavors, cocoa, with the objective of understanding its relationship to sensory and risk perception, promotion of dependence, and enhancement of attractiveness and acceptability. Methods: We used the Legacy Tobacco Documents Library to identify documents relevant to our research questions. Initial search terms were generated following an examination of published literature on cocoa, other cigarette additives, and sensory and risk perception. Further research questions and search terms were generated based on review of documents generated from the initial search terms. Results: Cocoa is widely applied to cigarettes and has been used by the tobacco industry as an additive since the early 20th century. Cocoa can alter the sensory properties of cigarette smoke, including by providing a more appealing taste and decreasing its harshness. The tobacco industry has experimented with manipulating cocoa levels as a means of achieving sensory properties that appeal to women and youth. Conclusions: Although cocoa is identified as a flavor on tobacco industry Web sites, it may serve other sensory purposes in cigarettes as well. Eliminating cocoa as an additive from tobacco products may affect tobacco product abuse liability by altering smokers’ perceptions of product risk, and decreasing product appeal, especially among vulnerable populations. PMID:24610479

  19. A functional role for the colleters of coffee flowers

    PubMed Central

    Mayer, Juliana Lischka Sampaio; Carmello-Guerreiro, Sandra Maria; Mazzafera, Paulo

    2013-01-01

    Colleters are protuberances or trichomes that produce and release an exudate that overlays vegetative or reproductive buds. Colleters have a functional definition, as they are thought to protect young tissues against dehydration and pest attack. Decaffeinated coffee plants, named Decaffito®, have recently been obtained through chemical mutagenesis, and in addition to the absence of the alkaloid, the flowers of these plants open precociously. Decaffito mutants exhibit minimal production and secretion of the exudate by the colleters. We compared these mutants with normal coffee plants to infer the functional role of colleters and the secreted exudate covering flower buds. Decaffito mutants were obtained by sodium azide mutagenesis of Coffea arabica cv. Catuaí seeds. Wild-type plants were used as controls and are referred to as Catuaí. The flower colleters were analysed by scanning and transmission electron microscopy in addition to histochemical analysis. Histochemical analysis indicated the presence of heterogeneous exudate in the secretory cells of the colleters of both variants of coffee trees. Alkaloids were detected in Catuaí but not in Decaffito. Transmission electron microscopy revealed that the secretory cells in the Catuaí colleters possessed the normal and common characteristics found in secretory structures. In the secretory cells of the Decaffito colleters, it was not possible to identify any organelles or even the nucleus, but the cells had a darkened central cytoplasm, indicating that the secretion is produced in low amounts but not released. Our results offer a proof of concept of colleters in coffee, strongly indicating that the exudate covering the flower parts works as an adhesive to keep the petals together and the flower closed, which in part helps to avoid dehydration. Additionally, the exudate itself helps to prevent water loss from the epidermal cells of the petals.

  20. Searching for additional endocrine functions of the skeleton: genetic approaches and implications for therapeutics

    PubMed Central

    Wei, Jianwen; Flaherty, Stephen; Karsenty, Gerard

    2016-01-01

    Our knowledge of whole organism physiology has greatly advanced in the past decades through mouse genetics. In particular, genetic studies have revealed that most organs interact with one another through hormones in order to maintain normal physiological functions and the homeostasis of the entire organism. Remarkably, through these studies many unexpected novel endocrine means to regulate physiological functions have been uncovered. The skeletal system is one example. In this article, we review a series of studies that over the years have identified bone as an endocrine organ. The mechanism of action, pathological relevance, and therapeutic implications of the functions of the bone-derived hormone osteocalcin are discussed. In the last part of this review we discuss the possibility that additional endocrine functions of the skeleton may exist.

  1. Role of alloy additions on strengthening in 17-4 PH stainless steel

    NASA Astrophysics Data System (ADS)

    Murthy, Arpana Sudershan

    Alloy modifications by addition of niobium (Nb), vanadium (V), nitrogen (N) and cobalt (Co) to cast 17-4 PH steel were investigated to determine the effect on mechanical properties. Additions of Nb, V, and N increased the yield strength from 1120 MPa to 1310 MPa while decreased the room temperature charpy V notch (CVN) toughness from 20 J to four Joules. The addition of Co to cast 17-4 PH steel enhanced the yield strength and CVN toughness from 1140 MPa to 1290 MPa and from 3.7 J to 5.5 J, respectively. In the base 17-4 PH steel, an increase in block width from 2.27 ± 0.10 μm in the solution treated condition to 3.06 ± 0.17 μm upon aging at 755 K was measured using orientation image microscopy. Cobalt inhibited recrystallization and block boundary migration during aging resulting in a finer martensitic block structure. The influence of Co on copper (Cu) precipitation in steels was studied using atom probe tomography. A narrower precipitate size distribution was observed in the steels with Co addition. The concentration profile across the matrix / precipitate interface indicated rejection of Co atoms from the copper precipitates. This behavior was observed to be energetically favorable using first principle calculations. The activation energies for Cu precipitation increased from 205 kJ/ mol in the non-cobalt containing alloy, to 243 kJ/ mol, and 272 kJ/ mol in alloys with 3 wt. %Co, and 7 wt. % Co, respectively. The role of Co on Cu precipitation in cast 17-4 PH steel is proposed as follows: (i) Co is rejected out of the Cu precipitate and sets up a barrier to the growth of the Cu precipitate; (ii) results in Cu precipitates of smaller size and narrower distribution; (iii) the coarsening of Cu precipitates is inhibited; and (iv) the activation energy for Cu precipitation increases.

  2. The Use of Additive Manufacturing for Fabrication of Multi-Function Small Satellite Structures

    SciTech Connect

    Horais, Brian J; Love, Lonnie J; Dehoff, Ryan R

    2013-01-01

    The use of small satellites in constellations is limited only by the growing functionality of smallsats themselves. Additive manufacturing provides exciting new design opportunities for development of multifunction CubeSat structures that integrate such functions as propulsion and thermal control into the satellite structures themselves. Manufacturing of these complex multifunction structures is now possible in lightweight, high strength, materials such as titanium by using existing electron beam melting additive manufacturing processes. However, the use of today's additive manufacturing capabilities is often cost-prohibitive for small companies due to the large capital investments required. To alleviate this impediment the U.S. Department of Energy has established a Manufacturing Demonstration Facility (MDF) at their Oak Ridge National Laboratory (ORNL) in Tennessee that provides industry access to a broad range of energy-efficient additive manufacturing equipment for collaborative use by both small and large organizations. This paper presents a notional CubeSat multifunction design that integrates the propulsion system into a three-unit (3U) CubeSat structure. The full-scale structure has been designed and fabricated at the ORNL MDF. The use of additive manufacturing for spacecraft fabrication is opening up many new possibilities in design and fabrication capabilities for what had previously been impossible structures to fabricate.

  3. [Roles of additives and surface control in slurry atomization]. Quarterly report

    SciTech Connect

    Tsai, S.C.

    1992-06-01

    As reported in the quarterly report of March of 1992, the relative viscosity of a Newtonian Coal Water Slurry (CWS) in the presence of an anionic polymeric dispersant is an order of magnitude higher than the prediction of the well established Krieger-Dougherty Equation which describes the relative viscosity of a non-aggregated Newtonian suspension as a function of particle volume fraction. Note that the anionic dispersant is used in such a quantity that the resulting interparticle electrostatic repulsion counter-balances the interparticle van der Waals attraction. Investigation continues to determine the mechanisms of such excess energy dissipation under shear. New experimental results are presented in this report to verify the role of the anionic polymeric dispersant in such excess energy dissipation of CWS.

  4. Compositions, Functions, and Testing of Friction Brake Materials and Their Additives

    SciTech Connect

    Blau, PJ

    2001-10-22

    The purpose of this report is to present a survey of commercial brake materials and additives, and to indicate their typical properties and functions, especially as regards their use in heavy trucks. Most truck pad and shoe materials described here were designed to wear against cast iron. Brake material test methods are also briefly described. This report does not address issues associated with the fabrication and manufacturing of brake materials. Since there are literally thousands of brake material additives, and their combinations are nearly limitless, it is impractical to list them all here. Rather, an attempt has been made to capture the primary constituents and their functions. An Appendix contains thermo-physical properties of some current and potential brake materials.

  5. Functional aortic stiffness: role of CD4+ T lymphocytes

    PubMed Central

    Majeed, Beenish A.; Eberson, Lance S.; Tawinwung, Supannikar; Larmonier, Nicolas; Secomb, Timothy W.; Larson, Douglas F.

    2015-01-01

    The immune system is suggested to be essential in vascular remodeling and stiffening. To study the dependence upon lymphocytes in vascular stiffening, we compared an angiotensin II-model of vascular stiffening in normal C57BL/6J mice with lymphocyte-deficient RAG 1−/− mice and additionally characterized the component of vascular stiffness due to vasoconstriction vs. vascular remodeling. Chronic angiotensin II increased aortic pulse wave velocity, effective wall stiffness, and effective Young's modulus in C57BL/6J mice by three-fold but caused no change in the RAG 1−/− mice. These functional measurements were supported by aortic morphometric analysis. Adoptive transfer of CD4+ T helper lymphocytes restored the angiotensin II-mediated aortic stiffening in the RAG 1−/− mice. In order to account for the hydraulic vs. material effects of angiotensin II on pulse wave velocity, subcutaneous osmotic pumps were removed after 21 days of angiotensin II-infusion in the WT mice to achieve normotensive values. The pulse wave velocity (PWV) decreased from three- to two-fold above baseline values up to 7 days following pump removal. This study supports the pivotal role of the CD4+ T-lymphocytes in angiotensin II-mediated vascular stiffening and that angiotensin II-mediated aortic stiffening is due to the additive effect of active vascular smooth muscle vasoconstriction and vascular remodeling. PMID:26379554

  6. Role of Striatal-Enriched Tyrosine Phosphatase in Neuronal Function.

    PubMed

    Kamceva, Marija; Benedict, Jessie; Nairn, Angus C; Lombroso, Paul J

    2016-01-01

    Striatal-enriched protein tyrosine phosphatase (STEP) is a CNS-enriched protein implicated in multiple neurologic and neuropsychiatric disorders. STEP regulates key signaling proteins required for synaptic strengthening as well as NMDA and AMPA receptor trafficking. Both high and low levels of STEP disrupt synaptic function and contribute to learning and behavioral deficits. High levels of STEP are present in human postmortem samples and animal models of Alzheimer's disease, Parkinson's disease, and schizophrenia and in animal models of fragile X syndrome. Low levels of STEP activity are present in additional disorders that include ischemia, Huntington's chorea, alcohol abuse, and stress disorders. Thus the current model of STEP is that optimal levels are required for optimal synaptic function. Here we focus on the role of STEP in Alzheimer's disease and the mechanisms by which STEP activity is increased in this illness. Both genetic lowering of STEP levels and pharmacological inhibition of STEP activity in mouse models of Alzheimer's disease reverse the biochemical and cognitive abnormalities that are present. These findings suggest that STEP is an important point for modulation of proteins required for synaptic plasticity. PMID:27190655

  7. Role of Striatal-Enriched Tyrosine Phosphatase in Neuronal Function

    PubMed Central

    Lombroso, Paul J.

    2016-01-01

    Striatal-enriched protein tyrosine phosphatase (STEP) is a CNS-enriched protein implicated in multiple neurologic and neuropsychiatric disorders. STEP regulates key signaling proteins required for synaptic strengthening as well as NMDA and AMPA receptor trafficking. Both high and low levels of STEP disrupt synaptic function and contribute to learning and behavioral deficits. High levels of STEP are present in human postmortem samples and animal models of Alzheimer's disease, Parkinson's disease, and schizophrenia and in animal models of fragile X syndrome. Low levels of STEP activity are present in additional disorders that include ischemia, Huntington's chorea, alcohol abuse, and stress disorders. Thus the current model of STEP is that optimal levels are required for optimal synaptic function. Here we focus on the role of STEP in Alzheimer's disease and the mechanisms by which STEP activity is increased in this illness. Both genetic lowering of STEP levels and pharmacological inhibition of STEP activity in mouse models of Alzheimer's disease reverse the biochemical and cognitive abnormalities that are present. These findings suggest that STEP is an important point for modulation of proteins required for synaptic plasticity. PMID:27190655

  8. The Role of Executive Functions in Numerical Magnitude Skills

    ERIC Educational Resources Information Center

    Kolkman, Meijke E.; Hoijtink, Herbert J. A.; Kroesbergen, Evelyn H.; Leseman, Paul P. M.

    2013-01-01

    Executive functions (EF) are closely related to math performance. Little is known, however, about the role of EF in numerical magnitude skills (NS), although these skills are widely acknowledged to be important precursors of math learning. The current study focuses on the different roles of updating, shifting, and inhibition in NS. EF and NS were…

  9. Interactive effects between N addition and disturbance on boreal forest ecosystem structure and function

    NASA Astrophysics Data System (ADS)

    Nordin, Annika; Strengbom, Joachim; From, Fredrik

    2014-05-01

    In management of boreal forests, nitrogen (N) enrichment from atmospheric deposition or from forest fertilization can appear in combination with land-use related disturbances, i.e. tree harvesting by clear-felling. Long-term interactive effects between N enrichment and disturbance on boreal forest ecosystem structure and function are, however, poorly known. We investigated effects of N enrichment by forest fertilization done > 25 years ago on forest understory species composition in old-growth (undisturbed) forests, and in forests clear-felled 10 years ago (disturbed). In clear-felled forests we also investigated effects of the previous N addition on growth of tree saplings. The results show that the N enrichment effect on the understory species composition was strongly dependent on the disturbance caused by clear-felling. In undisturbed forests, there were small or no effects on understory species composition from N addition. In contrast, effects were large in forests first exposed to N addition and subsequently disturbed by clear-felling. Effects of N addition differed among functional groups of plants. Abundance of graminoids increased (+232%) and abundance of dwarf shrubs decreased (-44%) following disturbance in N fertilized forests. For vascular plants, the two perturbations had contrasting effects on α-(within forests) and β-diversity (among forests): in disturbed forests, N addition reduced, or had no effect on α-diversity, while β-diversity increased. For bryophytes, negative effects of disturbance on α-diversity were smaller in N fertilized forests than in forests not fertilized, while neither N addition nor disturbance had any effects on β-diversity. Moreover, sapling growth in forests clear-felled 10 years ago was significantly higher in previously N fertilized forests than in forests not fertilized. Our study show that effects of N addition on plant communities may appear small, short-lived, or even absent until exposed to a disturbance. This

  10. Regioselectivity of radical additions to substituted alkenes: insight from conceptual density functional theory.

    PubMed

    De Vleeschouwer, Freija; Jaque, Pablo; Geerlings, Paul; Toro-Labbé, Alejandro; De Proft, Frank

    2010-08-01

    Radical additions to substituted alkenes are among the most important reactions in radical chemistry. Nonetheless, there is still some controversy in the literature about the factors that affect the rate and regioselectivity in these addition reactions. In this paper, the orientation of (nucleophilic) radical additions to electron-rich, -neutral, and -poor monosubstituted substrates (11 reactions in total) is investigated through the use of chemical concepts and reactivity descriptors. The regioselectivity of the addition of nucleophilic radicals on electron-rich and -neutral alkenes is thermodynamically controlled. An excellent correlation of 94% is found between the differences in activation barriers and in product stabilities (unsubstituted versus substituted site attack). Polar effects at the initial stage of the reaction play a significant role when electron-poor substrates are considered, lowering the extent of regioselectivity toward the unsubstituted sites, as predicted from the stability differences. This is nicely confirmed through an analysis for each of the 11 reactions using the spin-polarized dual descriptor, matching electrophilic and nucleophilic regions. PMID:20614876

  11. Microplastic moves pollutants and additives to worms, reducing functions linked to health and biodiversity.

    PubMed

    Browne, Mark Anthony; Niven, Stewart J; Galloway, Tamara S; Rowland, Steve J; Thompson, Richard C

    2013-12-01

    Inadequate products, waste management, and policy are struggling to prevent plastic waste from infiltrating ecosystems [1, 2]. Disintegration into smaller pieces means that the abundance of micrometer-sized plastic (microplastic) in habitats has increased [3] and outnumbers larger debris [2, 4]. When ingested by animals, plastic provides a feasible pathway to transfer attached pollutants and additive chemicals into their tissues [5-15]. Despite positive correlations between concentrations of ingested plastic and pollutants in tissues of animals, few, if any, controlled experiments have examined whether ingested plastic transfers pollutants and additives to animals. We exposed lugworms (Arenicola marina) to sand with 5% microplastic that was presorbed with pollutants (nonylphenol and phenanthrene) and additive chemicals (Triclosan and PBDE-47). Microplastic transferred pollutants and additive chemicals into gut tissues of lugworms, causing some biological effects, although clean sand transferred larger concentrations of pollutants into their tissues. Uptake of nonylphenol from PVC or sand reduced the ability of coelomocytes to remove pathogenic bacteria by >60%. Uptake of Triclosan from PVC diminished the ability of worms to engineer sediments and caused mortality, each by >55%, while PVC alone made worms >30% more susceptible to oxidative stress. As global microplastic contamination accelerates, our findings indicate that large concentrations of microplastic and additives can harm ecophysiological functions performed by organisms. PMID:24309271

  12. Patient advocacy in the USA: key communication role functions.

    PubMed

    Martin, Donald R; Tipton, Bryan K

    2007-09-01

    Researchers have long documented the importance of patient advocacy programs as a means of providing customer service in health-care organizations. Yet, while effective communication is often acknowledged as key to effective patient advocacy, knowledge of the specific communication role functions enacted by patient advocates remains limited, as does our understanding of the function of patient advocacy at the organizational level. This qualitative investigation not only provides a typology of communication roles enacted by patient advocates while solving problems on behalf of patients and their family members, but also integrates scholarly research on "boundary-spanning" as a means of theoretically contextualizing the advocacy role at the organizational level. PMID:17688476

  13. Role of Carbon-Addition and Hydrogen-Migration Reactions in Soot Surface Growth.

    PubMed

    Zhang, Hong-Bo; Hou, Dingyu; Law, Chung K; You, Xiaoqing

    2016-02-11

    Using density functional theory and master equation modeling, we have studied the kinetics of small unsaturated aliphatic molecules reacting with polycyclic aromatic hydrocarbon (PAH) molecules having a diradical character. We have found that these reactions follow the mechanism of carbon addition and hydrogen migration (CAHM) on both spin-triplet and open-shell singlet potential energy surfaces at a rate that is about ten times those of the hydrogen-abstraction-carbon-addition (HACA) reactions at 1500 K in the fuel-rich postflame region. The results also show that the most active reaction sites are in the center of the zigzag edges of the PAHs. Furthermore, the reaction products are more likely to form straight rather than branched aliphatic side chains in the case of reacting with diacetylene. The computed rate constants are also found to be independent of pressure at conditions of interest in soot formation, and the activation barriers of the CAHM reactions are linearly correlated with the diradical characters. PMID:26799641

  14. How does your kidney smell? Emerging roles for olfactory receptors in renal function.

    PubMed

    Shepard, Blythe D; Pluznick, Jennifer L

    2016-05-01

    Olfactory receptors (ORs) are chemosensors that are responsible for one's sense of smell. In addition to this specialized role in the nose, recent evidence suggests that ORs are also found in a variety of additional tissues including the kidney. As this list of renal ORs continues to expand, it is becoming clear that they play important roles in renal and whole-body physiology, including a novel role in blood pressure regulation. In this review, we highlight important considerations that are crucial when studying ORs and present the current literature on renal ORs and their emerging relevance in maintaining renal function. PMID:26264790

  15. Immunotoxic effects of the color additive caramel color III: immune function studies in rats.

    PubMed

    Houben, G F; Penninks, A H; Seinen, W; Vos, J G; Van Loveren, H

    1993-01-01

    Administration of the color additive caramel color III (AC) may cause a reduction in total white blood cell counts in rats due to reduced lymphocyte counts. Beside lymphopenia, several other effects in rat have been described. The effects are caused by the imidazole derivative 2-acetyl-4(5)-(1,2,3,4-tetrahydroxybutyl)imidazole (THI) and occur in rats fed a diet low in vitamin B6. In the present paper, immune function studies on AC and THI with rats fed a diet low, but not deficient in vitamin B6 are presented and discussed. Rats were exposed to 0.4 or 4% AC or to 5.72 ppm THI in drinking water during and for 28 days prior to the start of immune function assays. Resistance to Trichinella spiralis was examined in an oral infection model and clearance of Listeria monocytogenes upon an intravenous infection was studied. In addition, natural cell-mediated cytotoxicity of splenic and nonadherent peritoneal cells and the antibody response to sheep red blood cells were studied. From the results it is concluded that exposure of rats to AC or THI influenced various immune function parameters. Thymus-dependent immunity was suppressed, while parameters of the nonspecific resistance were also affected, as shown by a decreased natural cell-mediated cytotoxicity in the spleen and an enhanced clearance of L. monocytogenes. PMID:8432426

  16. Nitric oxide and S-nitrosoglutathione function additively during plant immunity.

    PubMed

    Yun, Byung-Wook; Skelly, Michael J; Yin, Minghui; Yu, Manda; Mun, Bong-Gyu; Lee, Sang-Uk; Hussain, Adil; Spoel, Steven H; Loake, Gary J

    2016-07-01

    Nitric oxide (NO) is emerging as a key regulator of diverse plant cellular processes. A major route for the transfer of NO bioactivity is S-nitrosylation, the addition of an NO moiety to a protein cysteine thiol forming an S-nitrosothiol (SNO). Total cellular levels of protein S-nitrosylation are controlled predominantly by S-nitrosoglutathione reductase 1 (GSNOR1) which turns over the natural NO donor, S-nitrosoglutathione (GSNO). In the absence of GSNOR1 function, GSNO accumulates, leading to dysregulation of total cellular S-nitrosylation. Here we show that endogenous NO accumulation in Arabidopsis, resulting from loss-of-function mutations in NO Overexpression 1 (NOX1), led to disabled Resistance (R) gene-mediated protection, basal resistance and defence against nonadapted pathogens. In nox1 plants both salicylic acid (SA) synthesis and signalling were suppressed, reducing SA-dependent defence gene expression. Significantly, expression of a GSNOR1 transgene complemented the SNO-dependent phenotypes of paraquat resistant 2-1 (par2-1) plants but not the NO-related characters of the nox1-1 line. Furthermore, atgsnor1-3 nox1-1 double mutants supported greater bacterial titres than either of the corresponding single mutants. Our findings imply that GSNO and NO, two pivotal redox signalling molecules, exhibit additive functions and, by extension, may have distinct or overlapping molecular targets during both immunity and development. PMID:26916092

  17. Accessing siloxane functionalized polynorbornenes via vinyl-addition polymerization for CO2 separation membranes

    DOE PAGESBeta

    Mahurin, Shannon Mark; Sokolov, Alexei P.; Saito, Tomonori; Long, Brian K.; Gmernicki, Kevin R.; Hong, Eunice; Maroon, Christopher R.

    2016-07-06

    Here, the vinyl addition polymerization of norbornylbased monomers bearing polar functional groups is often problematic, leading to low molecular weight polymers in poor yield. Herein, we provide proof-of-principle evidence that addition-type homopolymers of siloxane substituted norbornyl-based monomers may be readily synthesized using the catalyst trans-[Ni(C6F5)2(SbPh3)2]. Polymerizations using this catalyst reached moderate to high conversion in just 5 min of polymerization and produced siloxanesubstituted polymers with molecular weights exceeding 100 kg/mol. These polymers showed excellent thermal stability (Td ≥ 362 °C) and were cast into membranes that displayed high CO2 permeability and enhanced CO2/N2 selectivity as compared to related materials.

  18. Meta-analysis of Functional Roles of DICCCOLs

    PubMed Central

    Yuan, Yixuan; Jiang, Xi; Zhu, Dajiang; Chen, Hanbo; Li, Kaiming; Lv, Peili; Yu, Xiang; Li, Xiaojin; Zhang, Shu; Zhang, Tuo; Hu, Xintao; Han, Junwei; Guo, Lei; Liu, Tianming

    2014-01-01

    DICCCOL (Dense Individualized and Common Connectivity-based Cortical Landmarks) is a recently published system composed of 358 cortical landmarks that possess consistent correspondences across individuals and populations. Meanwhile, each DICCCOL landmark is localized in an individual brain’s unique morphological profile, and therefore the DICCCOL system offers a universal and individualized brain reference and localization framework. However, in current 358 diffusion tensor imaging (DTI)-derived DICCCOLs, only 95 of them have been functionally annotated via task-based or resting-state fMRI datasets and the functional roles of other DICCCOLs are unknown yet. This work aims to take the advantage of existing literature fMRI studies (1110 publications) reported and aggregated in the BrainMap database to examine the possible functional roles of 358 DICCCOLs via meta-analysis. Our experimental results demonstrate that a majority of 358 DICCCOLs can be functionally annotated by the BrainMap database, and many DICCCOLs have rich and diverse functional roles in multiple behavior domains. This study provides novel insights into the functional regularity and diversity of 358 DICCCOLs, and offers a starting point for future elucidation of fine-grained functional roles of cortical landmarks. PMID:23055045

  19. Recyclable functionalization of silica with alcohols via dehydrogenative addition on hydrogen silsesquioxane.

    PubMed

    Moitra, Nirmalya; Kamei, Toshiyuki; Kanamori, Kazuyoshi; Nakanishi, Kazuki; Takeda, Kazuyuki; Shimada, Toyoshi

    2013-10-01

    Synthesis of class II hybrid silica materials requires the formation of covalent linkage between organic moieties and inorganic frameworks. The requirement that organosilylating agents be present to provide the organic part limits the synthesis of functional inorganic oxides, however, due to the water sensitivity and challenges concerning purification of the silylating agents. Synthesis of hybrid materials with stable molecules such as simple alcohols, rather than with these difficult silylating agents, may therefore provide a path to unprecedented functionality. Herein, we report the novel functionalization of silica with organic alcohols for the first time. Instead of using hydrolyzable organosilylating agents, we used stable organic alcohols with a Zn(II) catalyst to modify the surface of a recently discovered highly reactive macro-mesoporous hydrogen silsesquioxane (HSQ, HSiO1.5) monolith, which was then treated with water with the catalyst to form surface-functionalized silica. These materials were comprehensively characterized with FT-IR, Raman, solid-state NMR, fluorescence spectroscopy, thermal analysis, elemental analysis, scanning electron microscopy, and nitrogen adsorption-desorption measurements. The results obtained from these measurements reveal facile immobilization of organic moieties by dehydrogenative addition onto surface silane (Si-H) at room temperature with high loading and good tolerance of functional groups. The organic moieties can also be retrieved from the monoliths for recycling and reuse, which enables cost-effective and ecological use of the introduced catalytic/reactive surface functionality. Preservation of the reactivity of as-immobilized organic alcohols has been confirmed, moreover, by successfully performing copper-catalyzed azide-alkyne cycloaddition (CuAAC) "click" reactions on the immobilized silica surfaces. PMID:23977900

  20. Addition reaction of alkyl radical to C60 fullerene: Density functional theory study

    NASA Astrophysics Data System (ADS)

    Tachikawa, Hiroto; Kawabata, Hiroshi

    2016-02-01

    Functionalized fullerenes are known as a high-performance molecules. In this study, the alkyl-functionalized fullerenes (denoted by R-C60) have been investigated by means of the density functional theory (DFT) method to elucidate the effects of functionalization on the electronic states of fullerene. Also, the reaction mechanism of alkyl radicals with C60 was investigated. The methyl, ethyl, propyl, and butyl radicals (denoted by n = 1-4, where n means the number of carbon atoms in the alkyl radical) were examined as alkyl radicals. The DFT calculation showed that the alkyl radical binds to the carbon atom of C60 at the on-top site, and a strong C-C single bond is formed. The binding energies of alkyl radicals to C60 were distributed in the range of 31.8-35.1 kcal mol-1 at the CAM-B3LYP/6-311G(d,p) level. It was found that the activation barrier exists before alkyl addition, the barrier heights were calculated to be 2.1-2.8 kcal mol-1. The electronic states of R-C60 complexes were discussed on the basis of the theoretical results.

  1. Evaluation of the Performance of Smoothing Functions in Generalized Additive Models for Spatial Variation in Disease

    PubMed Central

    Siangphoe, Umaporn; Wheeler, David C.

    2015-01-01

    Generalized additive models (GAMs) with bivariate smoothing functions have been applied to estimate spatial variation in risk for many types of cancers. Only a handful of studies have evaluated the performance of smoothing functions applied in GAMs with regard to different geographical areas of elevated risk and different risk levels. This study evaluates the ability of different smoothing functions to detect overall spatial variation of risk and elevated risk in diverse geographical areas at various risk levels using a simulation study. We created five scenarios with different true risk area shapes (circle, triangle, linear) in a square study region. We applied four different smoothing functions in the GAMs, including two types of thin plate regression splines (TPRS) and two versions of locally weighted scatterplot smoothing (loess). We tested the null hypothesis of constant risk and detected areas of elevated risk using analysis of deviance with permutation methods and assessed the performance of the smoothing methods based on the spatial detection rate, sensitivity, accuracy, precision, power, and false-positive rate. The results showed that all methods had a higher sensitivity and a consistently moderate-to-high accuracy rate when the true disease risk was higher. The models generally performed better in detecting elevated risk areas than detecting overall spatial variation. One of the loess methods had the highest precision in detecting overall spatial variation across scenarios and outperformed the other methods in detecting a linear elevated risk area. The TPRS methods outperformed loess in detecting elevated risk in two circular areas. PMID:25983545

  2. Proposal for manipulating functional interface properties of composite organic semiconductors with addition of designed macromolecules.

    PubMed

    Maniadis, P; Lookman, T; Saxena, A; Smith, D L

    2012-06-22

    The arrangement of the electronic levels in an interface between organic semiconductors is crucial for the operation of devices such as solar cells and light emitting diodes. With the addition of designed macromolecules, we show that it is possible to control the relative position of the highest occupied molecular orbital and lowest unoccupied molecular orbital levels, and consequently improve the performance. The designed macromolecules consist of two end segments, each compatible with one of the interface components, and a central segment which adds functionality to the interface. The tails control the position and the orientation of the functional units. When the central functional unit is an electric dipole, an electrostatic field is created due to the orientation of the dipoles, which shifts the electronic levels in a controlled way. We develop a theoretical framework, based on self-consistent field theory, to study the concentration and the orientation of the central functional units. We find that the levels can shift by as much as several tenths of an eV. PMID:23004659

  3. Cinchona Alkaloid Catalyzed Sulfa-Michael Addition Reactions Leading to Enantiopure β-Functionalized Cysteines.

    PubMed

    Breman, Arjen C; Telderman, Suze E M; van Santen, Roy P M; Scott, Jamie I; van Maarseveen, Jan H; Ingemann, Steen; Hiemstra, Henk

    2015-11-01

    Sulfa-Michael additions to α,β-unsaturated N-acylated oxazolidin-2-ones and related α,β-unsaturated α-amino acid derivatives have been enantioselectively catalyzed by Cinchona alkaloids functionalized with a hydrogen bond donating group at the C6' position. The series of Cinchona alkaloids includes known C6' (thio)urea and sulfonamide derivatives and several novel species with a benzimidazole, squaramide or a benzamide group at the C6' position. The sulfonamides were especially suited as bifunctional organocatalysts as they gave the products in very good diastereoselectivity and high enantioselectivity. In particular, the C6' sulfonamides catalyzed the reaction with the α,β-unsaturated α-amino acid derivatives to afford the products in a diastereomeric ratio as good as 93:7, with the major isomer being formed in an ee of up to 99%. The products of the organocatalytic sulfa-Michael addition to α,β-unsaturated α-amino acid derivatives were subsequently converted in high yields to enantiopure β-functionalized cysteines suitable for native chemical ligation. PMID:26451627

  4. Structural and Functional Roles of Carotenoids in Chlorosomes

    PubMed Central

    Arellano, Juan B.; Collins, Aaron M.; Laurinmäki, Pasi; Torkkeli, Mika; Löflund, Benita; Serimaa, Ritva E.; Blankenship, Robert E.; Tuma, Roman

    2013-01-01

    Chlorosomes are large light-harvesting complexes found in three phyla of anoxygenic photosynthetic bacteria. Chlorosomes are primarily composed of self-assembling pigment aggregates. In addition to the main pigment, bacteriochlorophyll c, d, or e, chlorosomes also contain variable amounts of carotenoids. Here, we use X-ray scattering and electron cryomicroscopy, complemented with absorption spectroscopy and pigment analysis, to compare the morphologies, structures, and pigment compositions of chlorosomes from Chloroflexus aurantiacus grown under two different light conditions and Chlorobaculum tepidum. High-purity chlorosomes from C. aurantiacus contain about 20% more carotenoid per bacteriochlorophyll c molecule when grown under low light than when grown under high light. This accentuates the light-harvesting function of carotenoids, in addition to their photoprotective role. The low-light chlorosomes are thicker due to the overall greater content of pigments and contain domains of lamellar aggregates. Experiments where carotenoids were selectively extracted from intact chlorosomes using hexane proved that they are located in the interlamellar space, as observed previously for species belonging to the phylum Chlorobi. A fraction of the carotenoids are localized in the baseplate, where they are bound differently and cannot be removed by hexane. In C. tepidum, carotenoids cannot be extracted by hexane even from the chlorosome interior. The chemical structure of the pigments in C. tepidum may lead to π-π interactions between carotenoids and bacteriochlorophylls, preventing carotenoid extraction. The results provide information about the nature of interactions between bacteriochlorophylls and carotenoids in the protein-free environment of the chlorosome interior. PMID:23396908

  5. The role of local scale heterogeneities in terrestrial ecosystem functioning

    NASA Astrophysics Data System (ADS)

    Pappas, C.; Fatichi, S.; Rimkus, S.; Burlando, P.; Bugmann, H.; Huber, M.

    2013-12-01

    The coarse-grained spatial representation of many terrestrial ecosystem models hampers the importance of local scale heterogeneities. To discuss this issue, we combine a range of observations (forest inventories, eddy flux tower data, remote sensing products) and modeling approaches which allow us to investigate the role of local climate, topography and initial conditions (land cover and soil properties) when simulating vegetation dynamics. Three approaches for modeling terrestrial ecosystems, with contrasting degrees of abstraction, were selected: (i) LPJ, a well-established, area-based, Dynamic Global Vegetation Model (DGVM) that incorporates plant physiological and biogeochemical processes; (ii) LPJ-GUESS, a hybrid, individual-based approach that additionally considers more detailed processes of plant population dynamics; and (iii) D-LPJ, a spatially distributed version of LPJ, operating at a fine resolution (100m x 100m), which uses an enhanced hydrological representation accounting for lateral connectivity of surface and subsurface water fluxes. By confronting model simulations with a multivariate data-set available at the catchment scale, we argue that: (i) local environmental and topographic attributes that are often ignored or at best crudely represented within DGVM applications exert a strong control on terrestrial ecosystem functioning; (ii) the assumption of steady-state vegetation and soil carbon pools at the beginning of simulation studies (e.g., under 'current conditions'), as embedded in many DGVM applications, is in contradiction with the current state of many forests that, due to natural or anthropogenic disturbances, are often out of equilibrium; (iii) model evaluation against vegetation carbon fluxes (i.e., photosynthetic activity and respiration rates) does not imply an accurate simulation of vegetation carbon stocks (i.e., biomass). In addition, having gained insights about model performance at the catchment scale, where a wealth of information

  6. Functional role of lipoprotein receptors in Alzheimer's disease.

    PubMed

    Jaeger, Sebastian; Pietrzik, Claus U

    2008-02-01

    The LDL receptor gene family constitutes a class of structurally closely related cell surface receptors fulfilling diverse functions in different organs, tissues, and cell types. The LDL receptor is the prototype of this family, which also includes the VLDLR, ApoER2/LRP8, LRP1 and LRP1B, as well as Megalin/GP330, SorLA/LR11, LRP5, LRP6 and MEGF7. Recently several lines of evidence have positioned the LDL receptor gene family as one of the key players in Alzheimer's disease (AD) research. Initially this receptor family was of high interest due to its key function in cholesterol/apolipoprotein E (ApoE) uptake, with the epsilon4 allele of ApoE as the strongest genetic risk factor for late-onset AD. It has been established that the cholesterol metabolism of the cell has a strong impact on the production of Abeta, the major component of the plaques found in the brain of AD-patients. The original report that soluble amyloid precursor protein (APP) containing the kunitz proteinase inhibitor (KPI) domain might act as a ligand for LRP1 led to a complex investigation of the interaction of both proteins and their potential function in AD development. Meanwhile, it has been demonstrated that LRP1 might bind to APP independent of the KPI domain in APP. This APP - LRP1 interaction is facilitated through a trimeric complex of APP-FE65-LRP1, which has a functional role in APP processing. Along with LRP1, APP is transported from the early secretory compartments to the cell surface and subsequently internalised into the endosomal / lysosomal compartments. Recent investigations indicate that ApoER2 and SorLA fulfil a similar role in shifting APP localisation in the cell, which affects APP processing and the production of the APP derived amyloid beta-peptide (Abeta). In addition to the effect of lipoprotein receptors on APP processing and Abeta production, LRP1 has been shown to bind Abeta directly or indirectly through Abeta-lactoferrin, Abeta-alpha2M and Abeta-ApoE complexes in

  7. Integrating products of Bessel functions with an additional exponential or rational factor

    NASA Astrophysics Data System (ADS)

    Van Deun, Joris; Cools, Ronald

    2008-04-01

    We provide two MATLAB programs to compute integrals of the form ex∏i=1kJν_i(ax)dxand 0∞xr+x∏i=1kJν_i(ax)dx with Jν_i(x) the Bessel function of the first kind and (real) order ν. The parameter m is a real number such that ∑ν+m>-1 (to assure integrability near zero), r is real and the numbers c and a are all strictly positive. The program can deliver accurate error estimates. Program summaryProgram title: BESSELINTR, BESSELINTC Catalogue identifier: AEAH_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEAH_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 1601 No. of bytes in distributed program, including test data, etc.: 13 161 Distribution format: tar.gz Programming language: Matlab (version ⩾6.5), Octave (version ⩾2.1.69) Computer: All supporting Matlab or Octave Operating system: All supporting Matlab or Octave RAM: For k Bessel functions our program needs approximately ( 500+140k) double precision variables Classification: 4.11 Nature of problem: The problem consists in integrating an arbitrary product of Bessel functions with an additional rational or exponential factor over a semi-infinite interval. Difficulties arise from the irregular oscillatory behaviour and the possible slow decay of the integrand, which prevents truncation at a finite point. Solution method: The interval of integration is split into a finite and infinite part. The integral over the finite part is computed using Gauss-Legendre quadrature. The integrand on the infinite part is approximated using asymptotic expansions and this approximation is integrated exactly with the aid of the upper incomplete gamma function. In the case where a rational factor is present, this factor is first expanded in a Taylor series around infinity. Restrictions: Some (and eventually all

  8. Role of histone modifications in defining chromatin structure and function.

    PubMed

    Gelato, Kathy A; Fischle, Wolfgang

    2008-04-01

    Chromosomes in eukaryotic cell nuclei are not uniformly organized, but rather contain distinct chromatin elements, with each state having a defined biochemical structure and biological function. These are recognizable by their distinct architectures and molecular components, which can change in response to cellular stimuli or metabolic requirements. Chromatin elements are characterized by the fundamental histone and DNA components, as well as other associated non-histone proteins and factors. Post-translational modifications of histone proteins in particular often correlate with a specific chromatin structure and function. Patterns of histone modifications are implicated as having a role in directing the level of chromatin compaction, as well as playing roles in multiple functional pathways directing the readout of distinct regions of the genome. We review the properties of various chromatin elements and the apparent links of histone modifications with chromatin organization and functional output. PMID:18225984

  9. Differential Expression of Functional Fc-Receptors and Additional Immune Complex Receptors on Mouse Kidney Cells

    PubMed Central

    Suwanichkul, Adisak; Wenderfer, Scott E.

    2013-01-01

    The precise mechanisms by which circulating immune complexes accumulate in the kidney to form deposits in glomerulonephritis are not well understood. In particular, the role of resident cells within glomeruli of the kidney has been widely debated. Immune complexes have been shown to bind one glomerular cell type (mesangial cells) leading to functional responses such as pro-inflammatory cytokine production. To further assess the presence of functional immunoreceptors on resident glomerular cells, cultured mouse renal epithelial, endothelial, and mesangial cells were treated with heat-aggregated mouse IgG or preformed murine immune complexes. Mesangial and renal endothelial cells were found to bind IgG complexes, whereas glomerular epithelial cell binding was minimal. A blocking antibody for Fc-gamma receptors reduced binding to mesangial cells but not renal endothelial cells, suggesting differential immunoreceptor utilization. RT-PCR and immunostaining based screening of cultured renal endothelial cells showed limited low-level expression of known Fc-receptors and Igbinding proteins. The interaction between mesangial cells and renal endothelial cells and immune complexes resulted in distinct, cell-specific patterns of chemokine and cytokine production. This novel pathway involving renal endothelial cells likely contributes to the predilection of circulating immune complex accumulation within the kidney and to the inflammatory responses that drive kidney injury. PMID:23911392

  10. Phospha-Michael Addition as a New Click Reaction for Protein Functionalization.

    PubMed

    Lee, Yan-Jiun; Kurra, Yadagiri; Liu, Wenshe R

    2016-03-15

    A new type of click reaction between an alkyl phosphine and acrylamide was developed and applied for site-specific protein labeling in vitro and in live cells. Acrylamide is a small electrophilic olefin that readily undergoes phospha-Michael addition with an alkyl phosphine. Our kinetic study indicated a second-order rate constant of 0.07 m(-1)  s(-1) for the reaction between tris(2-carboxyethyl)phosphine and acrylamide at pH 7.4. To demonstrate its application in protein functionalization, we used a dansyl-phosphine conjugate to successfully label proteins that were site-specifically installed with N(ɛ) -acryloyl-l-lysine and employed a biotin-phosphine conjugate to selectively probe human proteins that were metabolically labeled with N-acryloyl-galactosamine. PMID:26756316

  11. The Mechanech: Role Function and Myth in Israeli Secondary Schools.

    ERIC Educational Resources Information Center

    Gordon, David; Ackerman, Walter I.

    1984-01-01

    Attempts to show that under certain circumstances, hidden curricula of schools perform an important function in maintenance of character myths. Applies Ernest Gellner's concept of conceptual incoherence to the role of the "Mechanech" (similar to American homeroom teachers, with responsibilities for pastoral care and moral education) in Israeli…

  12. Next-generation biomedical implants using additive manufacturing of complex, cellular and functional mesh arrays.

    PubMed

    Murr, L E; Gaytan, S M; Medina, F; Lopez, H; Martinez, E; Machado, B I; Hernandez, D H; Martinez, L; Lopez, M I; Wicker, R B; Bracke, J

    2010-04-28

    In this paper, we examine prospects for the manufacture of patient-specific biomedical implants replacing hard tissues (bone), particularly knee and hip stems and large bone (femoral) intramedullary rods, using additive manufacturing (AM) by electron beam melting (EBM). Of particular interest is the fabrication of complex functional (biocompatible) mesh arrays. Mesh elements or unit cells can be divided into different regions in order to use different cell designs in different areas of the component to produce various or continually varying (functionally graded) mesh densities. Numerous design elements have been used to fabricate prototypes by AM using EBM of Ti-6Al-4V powders, where the densities have been compared with the elastic (Young) moduli determined by resonant frequency and damping analysis. Density optimization at the bone-implant interface can allow for bone ingrowth and cementless implant components. Computerized tomography (CT) scans of metal (aluminium alloy) foam have also allowed for the building of Ti-6Al-4V foams by embedding the digital-layered scans in computer-aided design or software models for EBM. Variations in mesh complexity and especially strut (or truss) dimensions alter the cooling and solidification rate, which alters the alpha-phase (hexagonal close-packed) microstructure by creating mixtures of alpha/alpha' (martensite) observed by optical and electron metallography. Microindentation hardness measurements are characteristic of these microstructures and microstructure mixtures (alpha/alpha') and sizes. PMID:20308113

  13. A table of integrals of the error function. II - Additions and corrections.

    NASA Technical Reports Server (NTRS)

    Geller, M.; Ng, E. W.

    1971-01-01

    Integrals of products of error functions with other functions are presented, taking into account a combination of the error function with powers, a combination of the error function with exponentials and powers, a combination of the error function with exponentials of more complicated arguments, definite integrals from Laplace transforms, and a combination of the error function with trigonometric functions. Other integrals considered include a combination of the error function with logarithms and powers, a combination of two error functions, and a combination of the error function with other special functions.

  14. THE ROLE OF SEROTONIN IN RESPIRATORY FUNCTION AND DYSFUNCTION

    PubMed Central

    Hilaire, Gérard; Voituron, Nicolas; Menuet, Clément; Ichiyama, Ronaldo M.; Subramanian, Hari H.; Dutschmann, Mathias

    2010-01-01

    Serotonin (5-HT) is a neuro-modulator–transmitter influencing global brain function. Past and present findings illustrate a prominent role for 5-HT in the modulation of ponto-medullary autonomic circuits. 5-HT is also involved in the control of neurotrophic processes during pre- and postnatal development of neural circuits. The functional implications of 5-HT is particularly illustrated in the alterations to the serotonergic system, as seen in a wide range of neurological disorders. This article reviews the role of 5-HT in the development and control of respiratory networks in the ponto-medullary brainstem. The review further examines the role of 5-HT in breathing disorders occurring at different stages of life, in particular, the neonatal neurodevelopmental diseases such as Rett, sudden infant death and Prader-Willi syndromes, adult diseases such as sleep apnoea and mental illness linked to neurodegeneration. PMID:20801236

  15. Functional Role of Infective Viral Particles on Metal Reduction

    SciTech Connect

    Coates, John D.

    2014-04-01

    A proposed strategy for the remediation of uranium (U) contaminated sites was based on the immobilization of U by reducing the oxidized soluble U, U(VI), to form a reduced insoluble end product, U(IV). Previous studies identified Geobacter sp., including G. sulfurreducens and G. metallireducens, as predominant U(VI)-reducing bacteria under acetate-oxidizing and U(VI)-reducing conditions. Examination of the finished genome sequence annotation of the canonical metal reducing species Geobacter sulfurreducens strain PCA and G. metallireduceans strain GS-15 as well as the draft genome sequence of G. uraniumreducens strain Rf4 identified phage related proteins. In addition, the completed genome for Anaeromyxobacter dehalogenans and the draft genome sequence of Desulfovibrio desulfuricans strain G20, two more model metal-reducing bacteria, also revealed phage related sequences. The presence of these gene sequences indicated that Geobacter spp., Anaeromyxobacter spp., and Desulfovibrio spp. are susceptible to viral infection. Furthermore, viral populations in soils and sedimentary environments in the order of 6.4×10{sup 6}–2.7×10{sup 10} VLP’s cm{sup -3} have been observed. In some cases, viral populations exceed bacterial populations in these environments suggesting that a relationship may exist between viruses and bacteria. Our preliminary screens of samples collected from the ESR FRC indicated that viral like particles were observed in significant numbers. The objective of this study was to investigate the potential functional role viruses play in metal reduction specifically Fe(III) and U(VI) reduction, the environmental parameters affecting viral infection of metal reducing bacteria, and the subsequent effects on U transport.

  16. Role of Functional Electrical Stimulation in Tetraplegia Hand Surgery.

    PubMed

    Bersch, Ines; Fridén, Jan

    2016-06-01

    The use of functional electrical stimulation (FES) to improve upper limb function is an established method in the rehabilitation of persons with tetraplegia after spinal cord injury. Surgical reconstruction is another well-established yet underused technique to improve the performance of the upper extremities. Hand surgery plays an essential role in restoring hand function, mobility, and quality of life in the tetraplegic population. The knowledge about the effects of FES on a structural and functional level is fundamental for understanding how and when FES can be used best to support the effect of hand surgery, both pre- and postoperatively. In this article we discuss principles of FES and how FES improves functional outcome after surgical reconstruction. The reported results are based on preliminary clinical observations. PMID:27233590

  17. Syntactic Functions in Functional Discourse Grammar and Role and Reference Grammar: An Evaluative Comparison

    ERIC Educational Resources Information Center

    Butler, Christopher S.

    2012-01-01

    The aim of this paper is to compare the treatment of syntactic functions, and more particularly those traditionally labelled as Subject and Object, in Functional Discourse Grammar and Role and Reference Grammar. Relevant aspects of the overall structure of the two theories are briefly described. The concept of alignment between levels of the…

  18. Modification of Polymer Network Properties through the Addition of Functional Nanogel Particles

    NASA Astrophysics Data System (ADS)

    Liu, JianCheng

    Multifunctional acrylic and methacrylic monomers have been widely applied in many photopolymerization applications to produce crosslinked polymers with advantages such as rapid curing, broad choices of commercially available monomers and desirable physical and mechanical properties. However, there still remain critical challenges for these materials during polymerization including limited conversion and early onset of gelation as well as the generation of significant polymerization shrinkage and stress. This thesis explores the effects of network property modification through the addition of polymeric nanoparticles or nanogels. In order to understand the relationship between nanogel structure and composite material properties, nanogels with different architectures and functionalities were studied during polymerization in terms of kinetics, shrinkage and stress reduction, mechanical performance and reaction mechanisms. Nanogel composite formulations were evaluated to understand the interaction between nanogel structure with the resin matrix during polymerization through adjustment of nanogel branching densities and reactivity of polymer chain ends. It was found that both the chemical crosslinking from reactive chain ends and physical entanglements of high branching density nanogels with the resin matrix dramatically could improve final material mechanical strength. The reductions in overall volumetric shrinkage and shrinkage stress were found to follow at least proportional behavior with respect to nanogel loading concentration while maintaining similar final conversion and modulus results compared with the control resin. Nanogels containing unique functionalities were designed in order to modify reaction mechanism during secondary polymerization. A nanogel containing an integrated photoinitiator and active chain-end RAFT groups was able to initiate secondary polymerization from the nanogel phase so that localized polymerization was achieved from the beginning of

  19. Role of inorganic additives on the ballistic performance of gun propellant formulations.

    PubMed

    Damse, R S; Sikder, A K

    2008-06-15

    This paper explores the possibility of increasing the ballistic performance of gun propellant with the addition of inorganic additives viz. aluminium and ammonium perchlorate. Compositions based on propellant NQ containing additional aluminium and ammonium perchlorate in different parts were studied theoretically and experimentally. Performance in respect of ballistic parameters, sensitivity, thermal characteristics, thermal stability and mechanical properties are evaluated and compared with that of the conventional triple base propellant NQ. Experimental data on comparative study indicate that the compositions containing aluminium and ammonium perchlorate are superior to propellant NQ in respect of energy. PMID:18206299

  20. The role of prop-1-ene-1,3-sultone as an additive in lithium-ion cells

    NASA Astrophysics Data System (ADS)

    Self, Julian; Hall, David S.; Madec, Lénaïc; Dahn, J. R.

    2015-12-01

    Density functional theory (DFT) is used in conjunction with experimental results to propose decomposition pathways that describe the role and ultimate fate of the PES additive in Li-ion batteries. Oxidation of PES produces carbonyl sulfide gas and ethene at the positive electrode, both experimentally observed byproducts. However, the calculated standard potential for simple PES oxidation, E0ox ∼ 6.7 V vs. Li/Li+, is quite high, suggesting this pathway is unlikely. A "reactive electrode model" is presented, in which the positive electrode material is a reagent in the pseudo-combustion of PES (and other solvents). This spontaneous process produces carbonyl sulfide, carbon dioxide, and a rock salt surface layer, all of which are experimentally observed. At the negative electrode, the reduction of PES occurs via two one-electron steps, where E0red,1 = 0.9 V and E0red,2 = 4.3 V. The reduced species, Li2PES, can react with hydrogen and methyl radicals to produce propene, methylpropene, propane and lithium sulfite. Nucleophilic Li2PES can also react with electrophilic PES, ethylene carbonate, or ethyl methyl carbonate. Eighteen possible organic sulphate 'building blocks' for the solid-electrolyte interphase (SEI) are presented. X-ray photoelectron spectroscopy (XPS) measurements demonstrate that PES reduction indeed results in both lithium sulfite and organic sulphate SEI components.

  1. Adding functionality with additive manufacturing: Fabrication of titanium-based antibiotic eluting implants.

    PubMed

    Cox, Sophie C; Jamshidi, Parastoo; Eisenstein, Neil M; Webber, Mark A; Hassanin, Hany; Attallah, Moataz M; Shepherd, Duncan E T; Addison, Owen; Grover, Liam M

    2016-07-01

    Additive manufacturing technologies have been utilised in healthcare to create patient-specific implants. This study demonstrates the potential to add new implant functionality by further exploiting the design flexibility of these technologies. Selective laser melting was used to manufacture titanium-based (Ti-6Al-4V) implants containing a reservoir. Pore channels, connecting the implant surface to the reservoir, were incorporated to facilitate antibiotic delivery. An injectable brushite, calcium phosphate cement, was formulated as a carrier vehicle for gentamicin. Incorporation of the antibiotic significantly (p=0.01) improved the compressive strength (5.8±0.7MPa) of the cement compared to non-antibiotic samples. The controlled release of gentamicin sulphate from the calcium phosphate cement injected into the implant reservoir was demonstrated in short term elution studies using ultraviolet-visible spectroscopy. Orientation of the implant pore channels were shown, using micro-computed tomography, to impact design reproducibility and the back-pressure generated during cement injection which ultimately altered porosity. The amount of antibiotic released from all implant designs over a 6hour period (<28% of the total amount) were found to exceed the minimum inhibitory concentrations of Staphylococcus aureus (16μg/mL) and Staphylococcus epidermidis (1μg/mL); two bacterial species commonly associated with periprosthetic infections. Antibacterial efficacy was confirmed against both bacterial cultures using an agar diffusion assay. Interestingly, pore channel orientation was shown to influence the directionality of inhibition zones. Promisingly, this work demonstrates the potential to additively manufacture a titanium-based antibiotic eluting implant, which is an attractive alternative to current treatment strategies of periprosthetic infections. PMID:27127071

  2. Stability of a general mixed additive-cubic functional equation in non-Archimedean fuzzy normed spaces

    SciTech Connect

    Xu Tianzhou; Rassias, John Michael; Xu Wanxin

    2010-09-15

    We establish some stability results concerning the general mixed additive-cubic functional equation in non-Archimedean fuzzy normed spaces. In addition, we establish some results of approximately general mixed additive-cubic mappings in non-Archimedean fuzzy normed spaces. The results improve and extend some recent results.

  3. DNA--a molecule in search of additional functions: recipient of pool wave emissions? A hypothesis.

    PubMed

    Doerfler, Walter

    2010-09-01

    Almost the entire nucleotide sequence of human DNA is functionally unaccounted for, although large parts of the human genome are transcribed. The genes, as defined by current molecular biology, comprise about 1.5-2% of the DNA molecule. It is proposed that DNA encodes additional, hitherto unrecognized functions. In this discussion, the total information inside and outside the universe we live in is termed the pool or the sum total, known or unknown, of all laws, matter, energy, concepts and events. In a hypothetical model, a Gedankenexperiment, it is suggested that the total of all information emits pool waves of an unknown physical nature. They could be related to black energy or have completely different qualities. The designation pool waves should not imply any similarity to electromagnetism. Further, DNA is suggested to have the capability of interacting with the pool waves and thus permit humans - to some partly genetically determined and yet very limited extent - to perceive information from the pool. Pool emissions might be one of the forces that have been instrumental in and are still driving evolution from simple oligonucleotides to DNA with ever more complex recipient capacities. It will be a major challenge for researchers in the field to unravel these and less hypothetical undetected coding principles in DNA. It is uncertain whether the current trend to search the available DNA sequences with ever more refined computer technology on the basis of our present understanding of biology will detect unknown coding systems. For molecular medicine, research into the genetics of the most common human diseases could profit from the elucidation of presently still ephemeral codes in human DNA. Young scientists with a proven record of original research deserve support for the pursuit of unconventional ideas. This concept of granting priorities will be of the utmost importance in advancing the field beyond current concepts in molecular biology. PMID:20356684

  4. The Roles and Functions of Medical Directors in Nursing Homes.

    PubMed

    Nanda, Aman

    2015-03-01

    The medical director is an important member of the healthcare team in a nursing home, and is responsible for overall coordination of care and for implementation of policies related to care of the residents in a nursing home. The residents in nursing homes are frail, medically complex, and have multiple disabilities. The medical director has an important leadership role in assisting nursing home administration in providing quality care that is consistent with current standards of care. This article provides an overview of roles and functions of the medical director, and suggests ways the medical director can be instrumental in achieving excellent care in today's nursing facilities. PMID:26056830

  5. Examining the Roles of Work Autonomous and Controlled Motivations on Satisfaction and Anxiety as a Function of Role Ambiguity.

    PubMed

    Gillet, Nicolas; Fouquereau, Evelyne; Lafrenière, Marc-André K; Huyghebaert, Tiphaine

    2016-07-01

    Past research in the self-determination theory has shown that autonomous motivation is associated with positive outcomes (e.g., work satisfaction), whereas controlled motivation is related to negative outcomes (e.g., anxiety). The purpose of the present research was to examine the moderating function of role ambiguity on the relationships between work autonomous and controlled motivations on the one hand, and work satisfaction and anxiety on the other. Six hundred and ninety-eight workers (449 men and 249 women) participated in this study. Results revealed that autonomous motivation was most strongly related to satisfaction when ambiguity was low. In addition, controlled motivation was most strongly related to anxiety when ambiguity was high. In other words, the present findings suggest that the outcomes associated with each form of motivation may vary as a function of role ambiguity. The present study thus offers meaningful insights for organizations, managers, and employees. PMID:27027579

  6. Erythorbyl laurate as a potential food additive with multi-functionalities: Interfacial characteristics and antioxidant activity.

    PubMed

    Park, Kyung-Min; Lee, Min Joo; Jo, Su-Kyung; Choi, Seung Jun; Lee, JaeHwan; Chang, Pahn-Shick

    2017-01-15

    The interfacial characteristics and antioxidant activities of erythorbyl laurate were investigated to provide information on practical applications as a multi-functional food additive. The critical micelle concentration (CMC) of erythorbyl laurate was 0.101mM and its foam stability was three times (half-life 24.33±0.94h) higher than that of Tween 20 (8.00±1.63h). In free radical scavenging assay, the negligible decrease in EC50 of erythorbyl laurate compared to erythorbic acid manifested that C-5 selective esterification of erythorbic acid with an acyl group (lauric acid) did not reduce the inherent antioxidant activity of the donor (erythorbic acid). Erythorbyl laurate formed lipid peroxides slower (i.e. retarded oxidation) in an emulsion system than did erythorbic acid. The localization of erythorbyl laurate as an emulsifier allowed the antioxidant molecules to be concentrated at the oil-water interface where oxidation is prevalent, which led to more effective retardation of lipid oxidation. PMID:27542455

  7. An investigation of functionalized electrolyte using succinonitrile additive for high voltage lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Chen, Renjie; Liu, Fan; Chen, Yan; Ye, Yusheng; Huang, Yongxin; Wu, Feng; Li, Li

    2016-02-01

    Succinonitrile (SN) has been used as functional additive to improve the thermal stability and broaden the oxidation electrochemical window of commercial electrolyte 1 M LiPF6/EC/DEC (1:1, by volume) for high-voltage LIBs (cathode: Li1.2Ni0.2Mn0.6O2, anode: Li). 1 wt % SN-based electrolyte showed a wide electrochemical oxidation window of 5.4 V vs Li+/Li and excellent thermal stability demonstrated by thermogravimetry (TG) and X-ray photoelectron spectroscopy (XPS), as well as theoretical analysis according to molecular orbital theory. The LNMO (Li1.2Ni0.2Mn0.6O2) battery with 1 wt % SN-based electrolyte showed better cyclability and capacity retention when charged to higher cut-off voltage. The improved battery performance is mainly attributed to the formation of uniform cathode electrolyte interface (CEI) formed by interfacial reactions between the LNMO cathode and electrolyte. The outcome of this work and the continuous research on this subject can generate critical knowledge for designing thermal stability electrolytes for large format lithium-ion batteries.

  8. Covalent Functionalization of Fluorinated Graphene and Subsequent Application as Water-based Lubricant Additive.

    PubMed

    Ye, Xiangyuan; Ma, Limin; Yang, Zhigang; Wang, Jinqing; Wang, Honggang; Yang, Shengrong

    2016-03-23

    Although the fluorinated graphene (FG) possesses numerous excellent properties, it can not be really applied in aqueous environments due to its high hydrophobicity. Therefore, how to achieve hydrophilic FG is a challenge. Here, a method of solvent-free urea melt synthesis is developed to prepare the hydrophilic urea-modified FG (UFG). Some characterizations via transmission electron microscopy (TEM), atomic force microscopy (AFM), Fourier transfer infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and thermo gravimetric analysis (TGA) demonstrate that the urea molecules can covalently functionalize the FG and the hydrophilic UFG can be prepared. According to the tribological tests run on an optimal-SRV-I reciprocation friction tester, it can be found that the antiwear ability of water can be largely improved by adding the appropriate UFG. When the concentration of UFG aqueous dispersion is 1 mg/mL, the sample of UFG-1 has the best antiwear ability with a 64.4% decrease of wear rate compared with that of the pure water (UFG-0), demonstrating the prepared UFG can be used as a novel and effective water-based lubricant additive. PMID:26923174

  9. Density functional theory study of the effects of alloying additions on sulfur adsorption on nickel surfaces

    NASA Astrophysics Data System (ADS)

    Malyi, Oleksandr I.; Chen, Zhong; Kulish, Vadym V.; Bai, Kewu; Wu, Ping

    2013-01-01

    Reactions of hydrogen sulfide (H2S) with Nickel/Ytrria-doped zirconia (Ni/YDZ) anode materials might cause degradation of the performance of solid oxide fuel cells when S containing fuels are used. In this paper, we employ density functional theory to investigate S adsorption on metal (M)-doped and undoped Ni(0 0 1) and Ni(1 1 1) surfaces. Based on the performed calculations, we analyze the effects of 12 alloying additions (Ag, Au, Al, Bi, Cd, Co, Cu, Fe, Sn, Sb, V, and Zn) on the temperature of transition between clean (S atoms do not adsorb on the surfaces) and contaminated (S atoms can adsorb on the surfaces spontaneously) M-doped Ni surfaces for different concentrations of H2S in the fuel. Predicted results are consistent with many experimental studies relevant to S poisoning of both Ni/YDZ and M-doped Ni/YDZ anode materials. This study is important to understand S poisoning phenomena and to develop new S tolerant anode materials.

  10. Generalized theory of resonance scattering (GTRS) using the translational addition theorem for spherical wave functions.

    PubMed

    Mitri, Farid

    2014-11-01

    The generalized theory of resonance scattering (GTRS) by an elastic spherical target in acoustics is extended to describe the arbitrary scattering of a finite beam using the addition theorem for the spherical wave functions of the first kind under a translation of the coordinate origin. The advantage of the proposed method over the standard discrete spherical harmonics transform previously used in the GTRS formalism is the computation of the off-axial beam-shape coefficients (BSCs) stemming from a closed-form partial-wave series expansion representing the axial BSCs in spherical coordinates. With this general method, the arbitrary acoustical scattering can be evaluated for any particle shape and size, whether the particle is partially or completely illuminated by the incident beam. Numerical examples for the axial and off-axial resonance scattering from an elastic sphere placed arbitrarily in the field of a finite circular piston transducer with uniform vibration are provided. Moreover, the 3-D resonance directivity patterns illustrate the theory and reveal some properties of the scattering. Numerous applications involving the scattering phenomenon in imaging, particle manipulation, and the characterization of multiphase flows can benefit from the present analysis because all physically realizable beams radiate acoustical waves from finite transducers as opposed to waves of infinite extent. PMID:25389166

  11. Limited role of functional differentiation in early diversification of animals

    PubMed Central

    Knope, M.L.; Heim, N.A.; Frishkoff, L.O.; Payne, J.L.

    2015-01-01

    The origin of most animal phyla and classes during the Cambrian explosion has been hypothesized to represent an ‘early burst’ of evolutionary exploration of functional ecological possibilities. However, the ecological history of marine animals has yet to be fully quantified, preventing an assessment of the early-burst model for functional ecology. Here we use ecological assignments for 18,621 marine animal genera to assess the relative timing of functional differentiation versus taxonomic diversification from the Cambrian to the present day. We find that functional diversity increased more slowly than would be expected given the history of taxonomic diversity. Contrary to previous inferences of rapid ecological differentiation from the early appearances of all well-fossilized phyla and classes, explicit coding of functional characteristics demonstrates that Cambrian genera occupied comparatively few modes of life. Functional diversity increased in the Ordovician and, especially, during the recoveries from the end-Permian and end-Cretaceous mass extinctions. Permanent shifts in the relationship between functional and taxonomic diversity following the era-bounding extinctions indicates a critical role for these biotic crises in coupling taxonomic and functional diversity. PMID:25737406

  12. Limited role of functional differentiation in early diversification of animals.

    PubMed

    Knope, M L; Heim, N A; Frishkoff, L O; Payne, J L

    2015-01-01

    The origin of most animal phyla and classes during the Cambrian explosion has been hypothesized to represent an 'early burst' of evolutionary exploration of functional ecological possibilities. However, the ecological history of marine animals has yet to be fully quantified, preventing an assessment of the early-burst model for functional ecology. Here we use ecological assignments for 18,621 marine animal genera to assess the relative timing of functional differentiation versus taxonomic diversification from the Cambrian to the present day. We find that functional diversity increased more slowly than would be expected given the history of taxonomic diversity. Contrary to previous inferences of rapid ecological differentiation from the early appearances of all well-fossilized phyla and classes, explicit coding of functional characteristics demonstrates that Cambrian genera occupied comparatively few modes of life. Functional diversity increased in the Ordovician and, especially, during the recoveries from the end-Permian and end-Cretaceous mass extinctions. Permanent shifts in the relationship between functional and taxonomic diversity following the era-bounding extinctions indicates a critical role for these biotic crises in coupling taxonomic and functional diversity. PMID:25737406

  13. The functional role of some tomato products on lipid profile and liver function in adult rats.

    PubMed

    Ibrahim, Hoda Salama; Ahmed, Lamiaa Ali; El-din, Maha Mohamed Essam

    2008-09-01

    This study was carried out to investigate the functional role of lycopene obtained from powder prepared from fresh tomato, tomato paste, and ketchup that contained equal amounts of lycopene based on levels of intake on body weight gain (BWG), feed intake, feed efficiency ratio (FER), lipid profiles, atherogenic index, and liver enzymes of hyperlipidemic rats. Forty-eight male albino rats were divided into two main groups: the first group (n = 6 rats) was kept on the basal diet as a normal control, while the second group (n = 42 rats) was fed a hyperlipidemic diet for 5 weeks to induce hyperlipidemia. The latter group was divided into seven subgroups: the first subgroup was the positive control group, while the others were supplemented with one of the tomato products at one of two levels (10 or 20 mg of lycopene/kg of diet). BWG, feed intake, and FER were calculated, and blood samples were collected to determine total lipids, total cholesterol, triglycerides, lipoprotein fractions, atherogenic index, and liver function in sera. Relative organ weights were also calculated. Results revealed that administration of various tomato products produced a significant reduction in feed intake except for the hyperlipidemic group that supplemented with the lower lycopene level from tomato paste. In addition, BWG and FER were not influenced by addition of tomato products at any level of intake. Hyperlipidemic rats supplemented with tomato powder, tomato paste, or ketchup showed significant improvement in almost all the parameters studied compared to the positive control group. Results showed that the higher lycopene level from tomato paste produced significant improvement in all lipid parameters, followed by 10 mg of lycopene/kg from tomato paste, which caused significant elevation in high-density lipoprotein cholesterol comparable to that of the negative control group. The lowest atherogenic index was achieved by addition of the lower lycopene level from tomato paste followed by

  14. Hypotheses on the functional roles of chaotic transitory dynamics

    NASA Astrophysics Data System (ADS)

    Tsuda, Ichiro

    2009-03-01

    In contrast to the conventional static view of the brain, recent experimental data show that an alternative view is necessary for an appropriate interpretation of its function. Some selected problems concerning the cortical transitory dynamics are discussed. For the first time, we propose five scenarios for the appearance of chaotic itinerancy, which provides typical transitory dynamics. Second, we describe the transitory behaviors that have been observed in human and animal brains. Finally, we propose nine hypotheses on the functional roles of such dynamics, focusing on the dynamics embedded in data and the dynamical interpretation of brain activity within the framework of cerebral hermeneutics.

  15. Switching roles: the functional plasticity of adult tissue stem cells.

    PubMed

    Wabik, Agnieszka; Jones, Philip H

    2015-05-01

    Adult organisms have to adapt to survive, and the same is true for their tissues. Rates and types of cell production must be rapidly and reversibly adjusted to meet tissue demands in response to both local and systemic challenges. Recent work reveals how stem cell (SC) populations meet these requirements by switching between functional states tuned to homoeostasis or regeneration. This plasticity extends to differentiating cells, which are capable of reverting to SCs after injury. The concept of the niche, the micro-environment that sustains and regulates stem cells, is broadening, with a new appreciation of the role of physical factors and hormonal signals. Here, we review different functions of SCs, the cellular mechanisms that underlie them and the signals that bias the fate of SCs as they switch between roles. PMID:25812989

  16. Regulators of carcinogenesis: emerging roles beyond their primary functions.

    PubMed

    Jia, Lin-Tao; Zhang, Rui; Shen, Lan; Yang, An-Gang

    2015-02-01

    Cancers are characterized by aberrant cell signaling that results in accelerated proliferation, suppressed cell death, and reprogrammed metabolism to provide sufficient energy and intermediate metabolites for macromolecular biosynthesis. Here, we summarize the emerging "unconventional" roles of these regulators based on their newly identified interaction partners, different subcellular localizations, and/or structural variants. For example, the epidermal growth factor receptor (EGFR) regulates DNA synthesis, microRNA maturation and drug resistance by interacting with previously undescribed partners; cyclins and cyclin-dependent kinases (CDKs) crosstalk with multiple canonical pathways by phosphorylating novel substrates or by functioning as transcriptional factors; apoptosis executioners play extensive roles in necroptosis, autophagy, and in the self-renewal of stem cells; and various metabolic enzymes and their mutants control carcinogenesis independently of their enzymatic activity. These recent findings will supplement the systemic functional annotation of cancer regulators and provide new rationales for potential molecular targeted cancer treatments. PMID:25448403

  17. Switching roles: the functional plasticity of adult tissue stem cells

    PubMed Central

    Wabik, Agnieszka; Jones, Philip H

    2015-01-01

    Adult organisms have to adapt to survive, and the same is true for their tissues. Rates and types of cell production must be rapidly and reversibly adjusted to meet tissue demands in response to both local and systemic challenges. Recent work reveals how stem cell (SC) populations meet these requirements by switching between functional states tuned to homoeostasis or regeneration. This plasticity extends to differentiating cells, which are capable of reverting to SCs after injury. The concept of the niche, the micro-environment that sustains and regulates stem cells, is broadening, with a new appreciation of the role of physical factors and hormonal signals. Here, we review different functions of SCs, the cellular mechanisms that underlie them and the signals that bias the fate of SCs as they switch between roles. PMID:25812989

  18. Functional Roles of Syk in Macrophage-Mediated Inflammatory Responses

    PubMed Central

    Yi, Young-Su; Son, Young-Jin; Ryou, Chongsuk; Sung, Gi-Ho; Kim, Jong-Hoon; Cho, Jae Youl

    2014-01-01

    Inflammation is a series of complex biological responses to protect the host from pathogen invasion. Chronic inflammation is considered a major cause of diseases, such as various types of inflammatory/autoimmune diseases and cancers. Spleen tyrosine kinase (Syk) was initially found to be highly expressed in hematopoietic cells and has been known to play crucial roles in adaptive immune responses. However, recent studies have reported that Syk is also involved in other biological functions, especially in innate immune responses. Although Syk has been extensively studied in adaptive immune responses, numerous studies have recently presented evidence that Syk has critical functions in macrophage-mediated inflammatory responses and is closely related to innate immune response. This review describes the characteristics of Syk-mediated signaling pathways, summarizes the recent findings supporting the crucial roles of Syk in macrophage-mediated inflammatory responses and diseases, and discusses Syk-targeted drug development for the therapy of inflammatory diseases. PMID:25045209

  19. The Role of Additional Processing Time and Lexical Constraint in Spoken Word Recognition

    ERIC Educational Resources Information Center

    LoCasto, Paul C.; Connine, Cynthia M.; Patterson, David

    2007-01-01

    Three phoneme monitoring experiments examined the manner in which additional processing time influences spoken word recognition. Experiment 1a introduced a version of the phoneme monitoring paradigm in which a silent interval is inserted prior to the word-final target phoneme. Phoneme monitoring reaction time decreased as the silent interval…

  20. Latinas and Postpartum Depression: Role of Partner Relationship, Additional Children, and Breastfeeding

    ERIC Educational Resources Information Center

    Hassert, Silva; Kurpius, Sharon E. Robinson

    2011-01-01

    Breastfeeding, additional children, and partner relationship predicted postpartum depression among 59 Latinas who had an infant who was 6 months old or younger. The most powerful predictor was conflict with partner. Counselors working with Latinas experiencing postpartum depression should explore the partner relationship, particularly relationship…

  1. Testing a Gender Additive Model: The Role of Body Image in Adolescent Depression

    ERIC Educational Resources Information Center

    Bearman, Sarah Kate; Stice, Eric

    2008-01-01

    Despite consistent evidence that adolescent girls are at greater risk of developing depression than adolescent boys, risk factor models that account for this difference have been elusive. The objective of this research was to examine risk factors proposed by the "gender additive" model of depression that attempts to partially explain the increased…

  2. The Role of Thyroid Hormone in Testicular Development and Function

    PubMed Central

    Wagner, Márcia Santos; Wajner, Simone Magagnin; Maia, Ana Luiza

    2009-01-01

    Thyroid hormone is a critical regulator of growth, development and metabolism in virtually all tissues, and altered thyroid status affects many organs and systems. Although for many years testis has been regarded as a thyroid hormone unresponsive organ, it is now evident that thyroid hormone plays an important role in testicular development and function. A considerable amount of data shows that thyroid hormone influences steroidogenesis as well as spermatogenesis. The involvement of triiodothyronine (T3) in the control of Sertoli cell proliferation and functional maturation is widely accepted, as well as its role in postnatal Leydig cell differentiation and steroidogenesis. The presence of thyroid hormone receptors in testicular cells throughout development and in adulthood implies that T3 may act directly on these cells to bring about its effects. Several recent studies have employed different methodologies and techniques in an attempt to understand the mechanisms underlying thyroid hormone effects on testicular cells. The current review aims at presenting an updated picture of the recent advances made regarding the role of thyroid hormones in male gonadal function. PMID:18728126

  3. A role of BNLT compound addition on structure and properties of PZT ceramics

    NASA Astrophysics Data System (ADS)

    Jaita, P.; Watcharapasorn, A.; Jiansirisomboon, S.

    2010-09-01

    In this research, effects of lead-free bismuth sodium lanthanum titanate (BNLT) addition on structure and properties of lead zirconate titanate (PZT) ceramics were investigated. PZT ceramics with addition of 0.1-3.0 wt%BNLT were fabricated by a solid-state mixed oxide method and sintering at 1050-1200 °C for 2 h to obtain dense ceramics with at least 96% of theoretical density. X-ray diffraction indicated that complete solid solution occurred for all compositions. Phase identification showed both tetragonal and rhombohedral perovskite structure of PZT with no BNLT phase detected. Scanning electron micrographs of fractured PZT/BNLT ceramics showed equiaxed grain shape with both transgranular and intergranular fracture modes. Addition of BNLT was also found to reduce densification and effectively limited grain growth of PZT ceramic. Optimum Hv and KIC values were found to be 4.85 GPa and 1.56 MPa.m 1/2 for PZT/0.5 wt%BNLT sample. Among PZT/BNLT samples, room temperature dielectric constant seemed to be improved with increasing BNLT content. The maximum piezoelectric coefficient values were observed in pure PZT ceramic and were slightly decreased in BNLT-added samples. Small reduction of remanent polarization and coercive field in hysteresis loops was observed in BNLT-added samples, indicating a slightly suppressed ferroelectric interaction in this material system.

  4. Functional Roles of the Tetramer Organization of Malic Enzyme*

    PubMed Central

    Hsieh, Ju-Yi; Chen, Shao-Hung; Hung, Hui-Chih

    2009-01-01

    Malic enzyme has a dimer of dimers quaternary structure in which the dimer interface associates more tightly than the tetramer interface. In addition, the enzyme has distinct active sites within each subunit. The mitochondrial NAD(P)+-dependent malic enzyme (m-NAD(P)-ME) isoform behaves cooperatively and allosterically and exhibits a quaternary structure in dimer-tetramer equilibrium. The cytosolic NADP+-dependent malic enzyme (c-NADP-ME) isoform is noncooperative and nonallosteric and exists as a stable tetramer. In this study, we analyze the essential factors governing the quaternary structure stability for human c-NADP-ME and m-NAD(P)-ME. Site-directed mutagenesis at the dimer and tetramer interfaces was employed to generate a series of dimers of c-NADP-ME and m-NAD(P)-ME. Size distribution analysis demonstrated that human c-NADP-ME exists mainly as a tetramer, whereas human m-NAD(P)-ME exists as a mixture of dimers and tetramers. Kinetic data indicated that the enzyme activity of c-NADP-ME is not affected by disruption of the interface. There are no significant differences in the kinetic properties between AB and AD dimers, and the dimeric form of c-NADP-ME is as active as tetramers. In contrast, disrupting the interface of m-NAD(P)-ME causes the enzyme to be less active than wild type and to become less cooperative for malate binding; the kcat values of mutants decreased with increasing Kd,24 values, indicating that the dissociation of subunits at the dimer or tetramer interfaces significantly affects the enzyme activity. The above results suggest that the tetramer is required for a fully functional m-NAD(P)-ME. Taken together, the analytical ultracentrifugation data and the kinetic analysis of these interface mutants demonstrate the differential role of tetramer organization for the c-NADP-ME and m-NAD(P)-ME isoforms. The regulatory mechanism of m-NAD(P)-ME is closely related to the tetramer formation of this isoform. PMID:19416979

  5. The Role of Functional Foods in Cutaneous Anti-aging

    PubMed Central

    Cho, Soyun

    2014-01-01

    Oral supplementation of micronutrients, or functional foods, to prevent aging has gained much attention and popularity as society ages and becomes more affluent, and as science reveals the pathological mechanisms of aging. Aging of the skin combines biologic aging and extrinsic aging caused predominantly by sunlight and other environmental toxins. Anti-aging functional foods exert their influence mostly through their anti-oxidant and anti-inflammatory effects, thereby abrogating collagen degradation and/or increasing procollagen synthesis. Clinical evidence supporting a role in preventing cutaneous aging is available for oral supplements such as carotenoids, polyphenols, chlorophyll, aloe vera, vitamins C and E, red ginseng, squalene, and omega-3 fatty acids. Collagen peptides and proteoglycans are claimed to provide building blocks of the dermal matrix. This review summarizes the current study findings of these functional foods. PMID:26064850

  6. Role of AAA(+)-proteins in peroxisome biogenesis and function.

    PubMed

    Grimm, Immanuel; Erdmann, Ralf; Girzalsky, Wolfgang

    2016-05-01

    Mutations in the PEX1 gene, which encodes a protein required for peroxisome biogenesis, are the most common cause of the Zellweger spectrum diseases. The recognition that Pex1p shares a conserved ATP-binding domain with p97 and NSF led to the discovery of the extended family of AAA+-type ATPases. So far, four AAA+-type ATPases are related to peroxisome function. Pex6p functions together with Pex1p in peroxisome biogenesis, ATAD1/Msp1p plays a role in membrane protein targeting and a member of the Lon-family of proteases is associated with peroxisomal quality control. This review summarizes the current knowledge on the AAA+-proteins involved in peroxisome biogenesis and function. PMID:26453804

  7. Role of Micronutrients in Skin Health and Function

    PubMed Central

    Park, Kyungho

    2015-01-01

    Skin is the first line of defense for protecting our bodies against external perturbations, including ultraviolet (UV) irradiation, mechanical/chemical stress, and bacterial infection. Nutrition is one of many factors required for the maintenance of overall skin health. An impaired nutritional status alters the structural integrity and biological function of skin, resulting in an abnormal skin barrier. In particular, the importance of micronutrients (such as certain vitamins and minerals) for skin health has been highlighted in cell culture, animal, and clinical studies. These micronutrients are employed not only as active compounds in therapeutic agents for treating certain skin diseases, but also as ingredients in cosmetic products. Here, the author describes the barrier function of the skin and the general nutritional requirements for skin health. The goal of this review is to discuss the potential roles and current knowledge of selected micronutrients in skin health and function. PMID:25995818

  8. Role of XPD in cellular functions: To TFIIH and beyond.

    PubMed

    Houten, Bennett Van; Kuper, Jochen; Kisker, Caroline

    2016-08-01

    XPD, as part of the TFIIH complex, has classically been linked to the damage verification step of nucleotide excision repair (NER). However, recent data indicate that XPD, due to its iron-sulfur center interacts with the iron sulfur cluster assembly proteins, and may interact with other proteins in the cell to mediate a diverse set of biological functions including cell cycle regulation, mitosis, and mitochondrial function. In this perspective, after first reviewing the function and some of the key disease causing variants that affect XPD's interaction with TFIIH and the CDK-activating kinase complex (CAK), we investigate these intriguing cellular roles of XPD and highlight important unanswered questions that provide a fertile ground for further scientific exploration. PMID:27262611

  9. The Role of Functional Foods in Cutaneous Anti-aging.

    PubMed

    Cho, Soyun

    2014-03-01

    Oral supplementation of micronutrients, or functional foods, to prevent aging has gained much attention and popularity as society ages and becomes more affluent, and as science reveals the pathological mechanisms of aging. Aging of the skin combines biologic aging and extrinsic aging caused predominantly by sunlight and other environmental toxins. Anti-aging functional foods exert their influence mostly through their anti-oxidant and anti-inflammatory effects, thereby abrogating collagen degradation and/or increasing procollagen synthesis. Clinical evidence supporting a role in preventing cutaneous aging is available for oral supplements such as carotenoids, polyphenols, chlorophyll, aloe vera, vitamins C and E, red ginseng, squalene, and omega-3 fatty acids. Collagen peptides and proteoglycans are claimed to provide building blocks of the dermal matrix. This review summarizes the current study findings of these functional foods. PMID:26064850

  10. Roles for Oestrogen Receptor β in Adult Brain Function

    PubMed Central

    Handa, R. J.; Ogawa, S.; Wang, J. M.; Herbison, A. E.

    2012-01-01

    Oestradiol exerts a profound influence upon multiple brain circuits. For the most part, these effects are mediated by oestrogen receptor (ER)α. We review here the roles of ERβ, the other ER isoform, in mediating rodent oestradiol-regulated anxiety, aggressive and sexual behaviours, the control of gonadotrophin secretion, and adult neurogenesis. Evidence exists for: (i) ERβ located in the paraventricular nucleus underpinning the suppressive influence of oestradiol on the stress axis and anxiety-like behaviour; (ii) ERβ expressed in gonadotrophin-releasing hormone neurones contributing to oestrogen negative-feedback control of gonadotrophin secretion; (iii) ERβ controlling the offset of lordosis behaviour; (iv) ERβ suppressing aggressive behaviour in males; (v) ERβ modulating responses to social stimuli; and (vi) ERβ in controlling adult neurogenesis. This review highlights two major themes; first, ERβ and ERα are usually tightly inter-related in the oestradiol-dependent control of a particular brain function. For example, even though oestradiol feedback to control reproduction occurs principally through ERα-dependent mechanisms, modulatory roles for ERβ also exist. Second, the roles of ERα and ERβ within a particular neural network may be synergistic or antagonistic. Examples of the latter include the role of ERα to enhance, and ERβ to suppress, anxiety-like and aggressive behaviours. Splice variants such as ERβ2, acting as dominant negative receptors, are of further particular interest because their expression levels may reflect preceeding oestradiol exposure of relevance to oestradiol replacement therapy. Together, this review highlights the predominant modulatory, but nonetheless important, roles of ERβ in mediating the many effects of oestradiol upon adult brain function. PMID:21851428

  11. Additional role of second washing specimen obtained during single bronchoscopy session in diagnosis of pulmonary tuberculosis

    PubMed Central

    2013-01-01

    Background Flexible bronchoscopy with bronchial washing is a useful procedure for diagnosis of pulmonary tuberculosis (TB), when a patient cannot produce sputum spontaneously or when sputum smears are negative. However, the benefit of gaining serial bronchial washing specimens for diagnosis of TB has not yet been studied. Therefore, we conducted a retrospective study to determine the diagnostic utility of additional bronchial washing specimens for the diagnosis of pulmonary TB in suspected patients. Methods A retrospective analysis was performed on 174 patients [sputum smear-negative, n = 95 (55%); lack of sputum specimen, n = 79 (45%)] who received flexible bronchoscopy with two bronchial washing specimens with microbiological confirmation of pulmonary TB in Samsung Medical Center, between January, 2010 and December, 2011. Results Pulmonary TB was diagnosed by first bronchial washing specimen in 141 patients (81%) out of 174 enrolled patients, and an additional bronchial washing specimen established diagnosis exclusively in 22 (13%) patients. Smear for acid-fast bacilli (AFB) was positive in 46 patients (26%) for the first bronchial washing specimen. Thirteen patients (7%) were positive only on smear of an additional bronchial washing specimen. Combined smear positivity of the first and second bronchial washing specimens was significantly higher compared to first bronchial washing specimen alone [Total cases: 59 (34%) vs. 46 (26%), p < 0.001; cases for smear negative sputum: 25 (26%) vs. 18 (19%), p = 0.016; cases for poor expectoration: 34 (43%) vs. 28 (35%), p = 0.031]. The diagnostic yield determined by culture was also significantly higher in combination of the first and second bronchial washing specimens compared to the first bronchial washing. [Total cases: 163 (94%) vs. 141 (81%), p < 0.001; cases for smear negative sputum: 86 (91%) vs. 73 (77%), p < 0.001; cases for poor expectoration: 77 (98%) vs. 68 (86%), p = 0

  12. [The role of additives in bio-mass coal briquette on sulfur retention enhancement].

    PubMed

    Lu, Yongqi; Xu, Kangfu; Ma, Yongliang; Wei, Tiejun; Hao, Jiming

    2002-01-30

    The research first conducted the sulfur-fixing experiment of bio-mass coal briquette in a tubular furnace. The impacts of three additives Al2O3, Fe2O3 and MnO2 on the sulfur retention by calcium-based sorbent in briquette were investigated, and only Al2O3 displayed the enhancement of sulfur retention. The TGA experiment was further carried out, and proved that the high-temperature decomposition of CaSO4 in the deoxidization atmosphere was effectively inhibited with the addition of Al2O3. The XPS and XRD analyses of briquette ash showed that due to the interaction among Al2O3, CaSO4 and CaO, the composite CaSO4.3CaO.3Al2O3 which has more thermal stability was formed. With its wrapping or binding onto the surface of CaSO4 crystal, the decomposition of CaSO4 was mitigated. PMID:11987400

  13. Attosecond Pulse Carrier-Envelope Phase Effects: Roles of Frequency, Intensity and an Additional IR Pulse

    NASA Astrophysics Data System (ADS)

    Pronin, Evgeny A.; Peng, Liang-You; Starace, Anthony F.

    2008-05-01

    The effects of the carrier-envelope phase (CEP) of a few-cycle attosecond pulse on ionized electron momentum and energy spectra are analyzed, both with and without an additional few-cycle IR pulse [1, 2]. In the absence of an IR pulse, the CEP-induced asymmetries in the ionized electron momentum distributions are shown to vary as the 3/2 power of the attosecond pulse intensity. These asymmetries are also found to satisfy an approximate scaling law involving the frequency and intensity of the attosecond pulse. In the presence of even a very weak IR pulse, the attosecond pulse CEP-induced asymmetries are found to be significantly augmented. In addition, for higher IR laser intensities, we observe for low electron energies peaks separated by the IR photon energy in one electron momentum direction along the laser polarization axis; in the opposite direction, we find structured peaks that are spaced by twice the IR photon energy. Possible physical mechanisms for such asymmetric, low-energy structures in the ionized electron momentum distribution are proposed. Our results are based on single-active-electron solutions of the 3D TDSE for H and He. [1] Peng LY, Pronin EA, and Starace AF, New J. Phys. 10, xxx (2008); [2] Peng LY, Starace AF, Phys. Rev. A 76, 043401 (2007)

  14. Recovery of motor and cognitive function after cerebellar lesions in a songbird – role of estrogens

    PubMed Central

    Spence, Rory D.; Zhen, Yin; White, Stephanie; Schlinger, Barney A.; Day, Lainy B.

    2010-01-01

    In addition to its key role in complex motor function, the cerebellum is increasingly recognized to have a role in cognition. Songbirds are particularly good models for the investigation of motor and cognitive processes but little is known about the role of the songbird cerebellum in these processes. To explore cerebellar function in a songbird, we lesioned the cerebellum of adult female zebra finches and examined the effects on a spatial working memory task and on motor function during this task. There is evidence for steroid synthesis in the songbird brain and neurosteroids may have an impact on some forms of neural plasticity in adult songbirds. We therefore hypothesized that neurosteroids would affect motor and cognitive function after a cerebellar injury. We found that cerebellar lesions produced deficits in motor and cognitive aspects of a spatial task. In line with our prediction, birds in which estrogen synthesis was blocked had impaired performance in our spatial task compared with those that had estrogen synthesis blocked but estrogen replaced. There was no clear effect of estrogen replacement on motor function. We also found that lesions induced expression of the estrogen synthetic enzyme aromatase in reactive astrocytes and Bergmann glia around a cerebellar lesion. These data suggest that the cerebellum of songbirds mediates both motor and cognitive function and that estrogens may improve the recovery of cognitive aspects of cerebellar function after injury. PMID:19302157

  15. Synthesis and Characterization of Amine Functionalized Vegetable Oil as Lubricant Additive

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The majority of the lubricants and additives currently used are petroleum based that are toxic to the environment, making it increasingly difficult for safe and easy disposal. There has been an increasing demand for green lubricants and lubricant additives in recent years due to concerns about thei...

  16. Possible additional roles in mating for Ustilago maydis Rho1 and 14-3-3 homologues

    PubMed Central

    Pham, Cau D

    2010-01-01

    Both the Rho GTPases and 14-3-3 proteins each belong to ubiquitous families of proteins involved in a variety of cellular processes, including cytokinesis, cell polarity, cellular differentiation and apoptosis. In fungi, these components of signaling pathways are involved in cell cycle regulation, cytokinesis and virulence. We study cellular differentiation and pathogenesis for Ustilago maydis, the dimorphic fungal pathogen of maize. We have reported on the interactions of Pdc1, a U. maydis homologue of human 14-3-3ɛ, with Rho1, a small GTP binding protein; these proteins participate in cell polarity and filamentation pathways that include another small G protein, Rac1, and its effector PAK kinase, Cla4. Here we describe additional experiments that explore possible relationships of Pdc1 and Rho1 with another PAK-like kinase pathway and with the a matingtype locus. PMID:20539785

  17. Assessing the factor structure of a role functioning item bank

    PubMed Central

    Ware, John E.; Bjorner, Jakob B.

    2013-01-01

    Purpose Role functioning (RF) is an important part of health-related quality of life, but is hard to measure due to the wide definition of roles and fluctuations in role participation. This study aims to explore the dimensionality of a newly developed item bank assessing the impact of health on RF. Methods A battery of measures with skip patterns including the new RF bank was completed by 2,500 participants answering only questions on social roles relevant to them. Confirmatory factor analyses were conducted for the participants answering items from all conceptual domains (N = 1193). Conceptually based dimensionality and method effects reflecting positively and negatively worded items were explored in a series of models. Results A bi-factor model (CFI = .93, RMSEA = .08) with one general and four conceptual factors (social, family, occupation, generic) was retained. Positively worded items were excluded from the final solution due to misfit. While a single factor model with methods factors had a poor fit (CFI = .88, RMSEA = .13), high loadings on the general factor in the bi-factor model suggest that the RF bank is sufficiently unidimensional for IRT analysis. Conclusions The bank demonstrated sufficient unidimensionality for IRT-based calibration of all the items on a common metric and development of a computerized adaptive test. PMID:21153710

  18. Possible functional roles of phase resetting during walking.

    PubMed

    Yamasaki, Taiga; Nomura, Taishin; Sato, Shunsuke

    2003-06-01

    The walking rhythm is known to show phase shift or "reset" in response to external impulsive perturbations. We tried to elucidate functional roles of the phase reset possibly used for the neural control of locomotion. To this end, a system with a double pendulum as a simplified model of the locomotor control and a model of bipedal locomotion were employed and analyzed in detail. In these models, a movement corresponding to the normal steady-state walking was realized as a stable limit cycle solution of the system. Unexpected external perturbations applied to the system can push the state point of the system away from its limit cycle, either outside or inside the basin of attraction of the limit cycle. Our mathematical analyses of the models suggested functional roles of the phase reset during walking as follows. Function 1: an appropriate amount of the phase reset for a given perturbation can contribute to relocating the system's state point outside the basin of attraction of the limit cycle back to the inside. Function 2: it can also be useful to reduce the convergence time (the time necessary for the state point to return to the limit cycle). In experimental studies during walking of animals and humans, the reset of walking rhythm induced by perturbations was investigated using the phase transition curve (PTC) or the phase resetting curve (PRC) representing phase-dependent responses of the walking. We showed, for the simple double-pendulum model, the existence of the optimal phase control and the corresponding PTC that could optimally realize the aforementioned functions in response to impulsive force perturbations. Moreover, possible forms of PRC that can avoid falling against the force perturbations were predicted by the biped model, and they were compared with the experimentally observed PRC during human walking. Finally, physiological implications of the results were discussed. PMID:12789495

  19. The role of mast cells in functional GI disorders.

    PubMed

    Wouters, Mira M; Vicario, Maria; Santos, Javier

    2016-01-01

    Functional gastrointestinal disorders (FGIDs) are characterized by chronic complaints arising from disorganized brain-gut interactions leading to dysmotility and hypersensitivity. The two most prevalent FGIDs, affecting up to 16-26% of worldwide population, are functional dyspepsia and irritable bowel syndrome. Their etiopathogenic mechanisms remain unclear, however, recent observations reveal low-grade mucosal inflammation and immune activation, in association with impaired epithelial barrier function and aberrant neuronal sensitivity. These findings come to challenge the traditional view of FGIDs as pure functional disorders, and relate the origin to a tangible organic substrate. The mucosal inflammatory infiltrate is dominated by mast cells, eosinophils and intraepithelial lymphocytes in the intestine of FGIDs. It is well established that mast cell activation can generate epithelial and neuro-muscular dysfunction and promote visceral hypersensitivity and altered motility patterns in FGIDs, postoperative ileus, food allergy and inflammatory bowel disease. This review will discuss the role of mucosal mast cells in the gastrointestinal tract with a specific focus on recent advances in disease mechanisms and clinical management in irritable bowel syndrome and functional dyspepsia. PMID:26194403

  20. Additive, modular functionalization of reactive self-assembled monolayers: toward the fabrication of multilevel optical storage media.

    PubMed

    Gentili, Denis; Barbalinardo, Marianna; Manet, Ilse; Durso, Margherita; Brucale, Marco; Mezzi, Alessio; Melucci, Manuela; Cavallini, Massimiliano

    2015-04-28

    We report a novel strategy based on iterative microcontact printing, which provides additive, modular functionalization of reactive SAMs by different functional molecules. We demonstrate that after printing the molecules form an interpenetrating network at the SAM surface preserving their individual properties. We exploited the process by fabricating new optical storage media that consist of a multilevel TAG. PMID:25824851

  1. Functional roles of connexins and pannexins in the kidney.

    PubMed

    Abed, Ahmed B; Kavvadas, Panagiotis; Chadjichristos, Christos E

    2015-08-01

    Kidneys are highly complex organs, playing a crucial role in human physiopathology, as they are implicated in vital processes, such as fluid filtration and vasomotor tone regulation. There is growing evidence that gap junctions are major determinants of renal physiopathology. It has been demonstrated that their expression or channel activity may vary depending on physiological and pathological situations within distinct renal compartments. While some studies have focused on the role of connexins in renal physiology, our knowledge regarding the functional relevance of pannexins is still very limited. In this paper, we provide an overview of the involvement of connexins, pannexins and their channels in various physiological processes related to different renal compartments. PMID:26082183

  2. The Function and Roles of ADAMTS-7 in Inflammatory Diseases

    PubMed Central

    Zhang, Yuying; Lin, Jiqiang; Wei, Fanhua

    2015-01-01

    The ADAMTS proteinases are a group of multidomain and secreted metalloproteinases containing the thrombospondin motifs. ADAMTS-7 is a member of ADAMTS family and plays a crucial role in the pathogenesis of arthritis. Overexpression of ADAMTS-7 gene promotes the breakdown of cartilage oligomeric matrix protein (COMP) matrix and accelerates the progression of both surgically induced osteoarthritis and collagen-induced arthritis. Moreover, ADAMTS-7 and tumor necrosis factor-α (TNF-α) form a positive feedback loop in osteoarthritis. More significantly, granulin-epithelin precursor, a growth factor has important roles in bone development and bone-associated diseases, disturbs the interaction between ADAMTS-7 and COMP, and prevents COMP degradation. This review is based on our results and provides an overview of current knowledge of ADAMTS-7, including its structure, function, gene regulation, and inflammatory diseases involvement. PMID:26696755

  3. Functional regulatory roles of microRNAs in atherosclerosis.

    PubMed

    Gao, Ya; Peng, Juan; Ren, Zhong; He, Ni-Ya; Li, Qing; Zhao, Xue-Shan; Wang, Mei-Mei; Wen, Hong-Yan; Tang, Zhi-Han; Jiang, Zhi-Sheng; Wang, Gui-Xue; Liu, Lu-Shan

    2016-09-01

    MicroRNAs are a group of endogenously small non-coding RNA molecules that downregulate gene expression at the post-transcriptional level through binding to the 3'UTR of target mRNAs. Recent findings have revealed a key role for microRNAs in the pathophysiological processes of atherosclerosis. As a complex disease, atherosclerosis is influenced by a combination of multiple genes and environmental factors. Both of them play a role in atherogenesis by affecting different types of cells (such as endothelial cell, vascular smooth muscle cell and monocyte/macrophage) function. MicroRNAs control the senescence and dysfunction of endothelial cells, proliferation and migration of vascular smooth muscle cells, and macrophage-driven cytokine production and polarization. By these effects, microRNAs can influence the processes of atherosclerosis and may represent new molecular targets for therapy. PMID:27384386

  4. Genome-wide meta-analysis of maize heterosis reveals the potential role of additive gene expression at pericentromeric loci

    PubMed Central

    2014-01-01

    QTL, and also suggests a model for the potential role of additive expression in the formation and conservation of heterosis for GY via dominant, multigenic quantitative trait loci. Our findings contribute to a deeper understanding of the multifactorial phenomenon of heterosis, and thus to the breeding of new high yielding varieties. PMID:24693880

  5. The Use of Functional Communication Training without Additional Treatment Procedures in an Inclusive School Setting

    ERIC Educational Resources Information Center

    Casey, Sean D.; Merical, Cheryl L.

    2006-01-01

    Functional communication training (FCT) is an intervention frequently used for students with developmental disabilities to reduce problematic behaviors and to increase prosocial behaviors. This intervention appears to be very effective when the communication responses trained are matched to the function of the student's problematic behaviors. In…

  6. G1/ELE Functions in the Development of Rice Lemmas in Addition to Determining Identities of Empty Glumes

    PubMed Central

    Liu, Mengjia; Li, Haifeng; Su, Yali; Li, Wenqiang; Shi, Chunhai

    2016-01-01

    Rice empty glumes, also named sterile lemmas or rudimentary lemmas according to different interpretations, are distinct from lemmas in morphology and cellular pattern. Consistently, the molecular mechanism to control the development of lemmas is different from that of empty glumes. Rice LEAFY HULL STERILE1(OsLHS1) and DROOPING LEAF(DL) regulate the cellular pattern and the number of vascular bundles of lemmas respectively, while LONG STERILE LEMMA1 (G1)/ELONGATED EMPTY GLUME (ELE) and PANICLE PHYTOMER2 (PAP2)/OsMADS34 determine identities of empty glumes. Though some progress has been made, identities of empty glumes remain unclear, and genetic interactions between lemma genes and glume genes have been rarely elucidated. In this research, a new G1/ELE mutant g1–6 was identified and the phenotype was analyzed. Similar to previously reported mutant lines of G1/ELE, empty glumes of g1–6 plants transform into lemma-like organs. Furthermore, Phenotypes of single and double mutant plants suggest that, in addition to their previously described gene-specific functions, G1/ELE and OsLHS1 play redundant roles in controlling vascular bundle number, cell volume, and cell layer number of empty glumes and lemmas. Meanwhile, expression patterns of G1/ELE in osmads1-z flowers and OsLHS1 in g1–6 flowers indicate they do not regulate each other at the level of transcription. Finally, down-regulation of the empty glume gene OsMADS34/PAP2 and ectopic expression of the lemma gene DL, in the g1–6 plants provide further evidence that empty glumes are sterile lemmas. Generally, our findings provided valuable information for better understanding functions of G1 and OsLHS1 in flower development and identities of empty glumes. PMID:27462334

  7. G1/ELE Functions in the Development of Rice Lemmas in Addition to Determining Identities of Empty Glumes.

    PubMed

    Liu, Mengjia; Li, Haifeng; Su, Yali; Li, Wenqiang; Shi, Chunhai

    2016-01-01

    Rice empty glumes, also named sterile lemmas or rudimentary lemmas according to different interpretations, are distinct from lemmas in morphology and cellular pattern. Consistently, the molecular mechanism to control the development of lemmas is different from that of empty glumes. Rice LEAFY HULL STERILE1(OsLHS1) and DROOPING LEAF(DL) regulate the cellular pattern and the number of vascular bundles of lemmas respectively, while LONG STERILE LEMMA1 (G1)/ELONGATED EMPTY GLUME (ELE) and PANICLE PHYTOMER2 (PAP2)/OsMADS34 determine identities of empty glumes. Though some progress has been made, identities of empty glumes remain unclear, and genetic interactions between lemma genes and glume genes have been rarely elucidated. In this research, a new G1/ELE mutant g1-6 was identified and the phenotype was analyzed. Similar to previously reported mutant lines of G1/ELE, empty glumes of g1-6 plants transform into lemma-like organs. Furthermore, Phenotypes of single and double mutant plants suggest that, in addition to their previously described gene-specific functions, G1/ELE and OsLHS1 play redundant roles in controlling vascular bundle number, cell volume, and cell layer number of empty glumes and lemmas. Meanwhile, expression patterns of G1/ELE in osmads1-z flowers and OsLHS1 in g1-6 flowers indicate they do not regulate each other at the level of transcription. Finally, down-regulation of the empty glume gene OsMADS34/PAP2 and ectopic expression of the lemma gene DL, in the g1-6 plants provide further evidence that empty glumes are sterile lemmas. Generally, our findings provided valuable information for better understanding functions of G1 and OsLHS1 in flower development and identities of empty glumes. PMID:27462334

  8. Incorporating clonal growth form clarifies the role of plant height in response to nitrogen addition.

    PubMed

    Gough, Laura; Gross, Katherine L; Cleland, Elsa E; Clark, Christopher M; Collins, Scott L; Fargione, Joseph E; Pennings, Steven C; Suding, Katharine N

    2012-08-01

    Nutrient addition to grasslands consistently causes species richness declines and productivity increases. Competition, particularly for light, is often assumed to produce this result. Using a long-term dataset from North American herbaceous plant communities, we tested whether height and clonal growth form together predict responses to fertilization because neither trait alone predicted species loss in a previous analysis. Species with a tall-runner growth form commonly increased in relative abundance in response to added nitrogen, while short species and those with a tall-clumped clonal growth form often decreased. The ability to increase in size via vegetative spread across space, while simultaneously occupying the canopy, conferred competitive advantage, although typically only the abundance of a single species within each height-clonal growth form significantly responded to fertilization in each experiment. Classifying species on the basis of two traits (height and clonal growth form) increases our ability to predict species responses to fertilization compared to either trait alone in predominantly herbaceous plant communities. Electronic supplementary material The online version of this article (doi:10.1007/s00442-012-2264-5) contains supplementary material, which is available to authorized users. PMID:22302512

  9. Number line estimation and mental addition: examining the potential roles of language and education.

    PubMed

    Laski, Elida V; Yu, Qingyi

    2014-01-01

    This study investigated the relative importance of language and education to the development of numerical knowledge. Consistent with previous research suggesting that counting systems that transparently reflect the base-10 system facilitate an understanding of numerical concepts, Chinese and Chinese American kindergartners' and second graders' number line estimation (0-100 and 0-1000) was 1 to 2 years more advanced than that of American children tested in previous studies. However, Chinese children performed better than their Chinese American peers, who were fluent in Chinese but had been educated in America, at kindergarten on 0-100 number lines, at second grade on 0-1000 number lines, and at both time points on complex addition problems. Overall, the pattern of findings suggests that educational approach may have a greater influence on numerical development than the linguistic structure of the counting system. The findings also demonstrate that, despite generating accurate estimates of numerical magnitude on 0-100 number lines earlier, it still takes Chinese children approximately 2 years to demonstrate accurate estimates on 0-1000 number lines, which raises questions about how to promote the mapping of knowledge across numerical scales. PMID:24135313

  10. The role and future of the Laser Technology in the Additive Manufacturing environment

    NASA Astrophysics Data System (ADS)

    Levy, Gideon N.

    The Additive Manufacturing (AM) was, in the early days, strongly inspired by upcoming laser technologies. The trend to apply lasers in manufacturing in the 1970's might be also be seen as the ignition point, as is evident in early precedent patents. During the evolvement of AM processes, many new systems based on various physical principals were evident; alternative energy sources for AM are in use today. Starting with the 'historical' background followed by a detailed classification analyzing the enablers in use, relevant laser technologies have been identified. This paper focuses on powder bed technologies for plastics and metals as the relevant Laser technology. It concentrates on laser influences and state-of-the-art knowledge. The paper will present a generalized, 'big picture' overview indicating 'lessons learned' and where future emphasis should be focused. Opportunities and challenges, including actual development status, will be described in view of the desired outcomes. Finally, future research challenges and conclusions will be stated and several relevant references for further readings will be given.

  11. The role of lipoprotein receptors on the physiological function of APP.

    PubMed

    Wagner, Timo; Pietrzik, Claus U

    2012-04-01

    In this review, we will primarily focus on the role of members of the low-density lipoprotein receptor (LDL-R) family that are involved in trafficking and processing of the amyloid precursor protein (APP). We will discuss the role of the LDL-receptor family members, low-density lipoprotein receptor-related protein 1 (LRP1), LRP1b, apolipoprotein E receptor 2, sortilin-related receptor (SorLA/LR11) and megalin/LRP2 on the physiological function of APP and its cellular localization. Additionally, we will focus on adaptor proteins that have been shown to influence the physiological function of LDL-R family members in combination with APP processing. The results in this review emphasize that the physiological function of APP cannot be explained by the focus on the APP protein alone but rather in combination with various direct or indirect interaction partners within the cellular environment. PMID:21947084

  12. The Effect of Small Molecule Additives on the Self-Assembly and Functionality of Protein-Polymer Diblock Copolymers

    NASA Astrophysics Data System (ADS)

    Thomas, Carla; Xu, Liza; Olsen, Bradley

    2013-03-01

    Self-assembly of globular protein-polymer block copolymers into well-defined nanostructures provides a route towards the manufacture of protein-based materials which maintains protein fold and function. The model material mCherry-b-poly(N-isopropyl acrylamide) forms self-assembled nanostructures from aqueous solutions via solvent evaporation. To improve retention of protein functionality when dehydrated, small molecules such as trehalose and glycerol are added in solution prior to solvent removal. With as little as 10 wt% additive, improvements in retained functionality of 20-60% are observed in the solid-state as compared to samples in which no additive is present. Higher additive levels (up to 50%) continue to show improvement until approximately 100% of the protein function is retained. These large gains are hypothesized to originate from the ability of the additives to replace hydrogen bonds normally fulfilled by water. The addition of trehalose in the bulk material also improves the thermal stability of the protein by 15-20 °C, while glycerol decreases the thermal stability. Materials containing up to 50% additives remain microphase separated, and, upon incorporation of additives, nanostructure domain spacing tends to increase, accompanied by order-order transitions.

  13. The Functional Role of the Periphery in Emotional Language Comprehension

    PubMed Central

    Havas, David A.; Matheson, James

    2013-01-01

    Language can impact emotion, even when it makes no reference to emotion states. For example, reading sentences with positive meanings (“The water park is refreshing on the hot summer day”) induces patterns of facial feedback congruent with the sentence emotionality (smiling), whereas sentences with negative meanings induce a frown. Moreover, blocking facial afference with botox selectively slows comprehension of emotional sentences. Therefore, theories of cognition should account for emotion-language interactions above the level of explicit emotion words, and the role of peripheral feedback in comprehension. For this special issue exploring frontiers in the role of the body and environment in cognition, we propose a theory in which facial feedback provides a context-sensitive constraint on the simulation of actions described in language. Paralleling the role of emotions in real-world behavior, our account proposes that (1) facial expressions accompany sudden shifts in wellbeing as described in language; (2) facial expressions modulate emotional action systems during reading; and (3) emotional action systems prepare the reader for an effective simulation of the ensuing language content. To inform the theory and guide future research, we outline a framework based on internal models for motor control. To support the theory, we assemble evidence from diverse areas of research. Taking a functional view of emotion, we tie the theory to behavioral and neural evidence for a role of facial feedback in cognition. Our theoretical framework provides a detailed account that can guide future research on the role of emotional feedback in language processing, and on interactions of language and emotion. It also highlights the bodily periphery as relevant to theories of embodied cognition. PMID:23750145

  14. Role of topology in complex functional networks of beta cells

    NASA Astrophysics Data System (ADS)

    Cherubini, Christian; Filippi, Simonetta; Gizzi, Alessio; Loppini, Alessandro

    2015-10-01

    The activity of pancreatic β cells can be described by biological networks of coupled nonlinear oscillators that, via electrochemical synchronization, release insulin in response to augmented glucose levels. In this work, we analyze the emergent behavior of regular and percolated β -cells clusters through a stochastic mathematical model where "functional" networks arise. We show that the emergence and robustness of the synchronized dynamics depend both on intrinsic and extrinsic parameters. In particular, cellular noise level, glucose concentration, network spatial architecture, and cell-to-cell coupling strength are the key factors for the generation of a rhythmic and robust activity. Their role in the functional network topology associated with β -cells clusters is analyzed and discussed.

  15. Covariant density functional theory: The role of the pion

    SciTech Connect

    Lalazissis, G. A.; Karatzikos, S.; Serra, M.; Otsuka, T.; Ring, P.

    2009-10-15

    We investigate the role of the pion in covariant density functional theory. Starting from conventional relativistic mean field (RMF) theory with a nonlinear coupling of the {sigma} meson and without exchange terms we add pions with a pseudovector coupling to the nucleons in relativistic Hartree-Fock approximation. In order to take into account the change of the pion field in the nuclear medium the effective coupling constant of the pion is treated as a free parameter. It is found that the inclusion of the pion to this sort of density functionals does not destroy the overall description of the bulk properties by RMF. On the other hand, the noncentral contribution of the pion (tensor coupling) does have effects on single particle energies and on binding energies of certain nuclei.

  16. Functional Gustatory Role of Chemoreceptors in Drosophila Wings.

    PubMed

    Raad, Hussein; Ferveur, Jean-François; Ledger, Neil; Capovilla, Maria; Robichon, Alain

    2016-05-17

    Neuroanatomical evidence argues for the presence of taste sensilla in Drosophila wings; however, the taste physiology of insect wings remains hypothetical, and a comprehensive link to mechanical functions, such as flight, wing flapping, and grooming, is lacking. Our data show that the sensilla of the Drosophila anterior wing margin respond to both sweet and bitter molecules through an increase in cytosolic Ca(2+) levels. Conversely, genetically modified flies presenting a wing-specific reduction in chemosensory cells show severe defects in both wing taste signaling and the exploratory guidance associated with chemodetection. In Drosophila, the chemodetection machinery includes mechanical grooming, which facilitates the contact between tastants and wing chemoreceptors, and the vibrations of flapping wings that nebulize volatile molecules as carboxylic acids. Together, these data demonstrate that the Drosophila wing chemosensory sensilla are a functional taste organ and that they may have a role in the exploration of ecological niches. PMID:27160896

  17. Field Effects in the CNS Play Functional Roles

    PubMed Central

    Weiss, Shennan A.; Faber, Donald S.

    2010-01-01

    An endogenous electrical field effect, i.e., ephaptic transmission, occurs when an electric field associated with activity occurring in one neuron polarizes the membrane of another neuron. It is well established that field effects occur during pathological conditions, such as epilepsy, but less clear if they play a functional role in the healthy brain. Here, we describe the principles of field effect interactions, discuss identified field effects in diverse brain structures from the teleost Mauthner cell to the mammalian cortex, and speculate on the function of these interactions. Recent evidence supports that relatively weak endogenous and exogenous field effects in laminar structures reach significance because they are amplified by network interactions. Such interactions may be important in rhythmogenesis for the cortical slow wave and hippocampal sharp wave–ripple, and also during transcranial stimulation. PMID:20508749

  18. Structure and functional roles of Epac2 (Rapgef4).

    PubMed

    Sugawara, Kenji; Shibasaki, Tadao; Takahashi, Harumi; Seino, Susumu

    2016-01-10

    Epac (exchange protein activated by cyclic-AMP) 2 is a direct target of 3'-5'-cyclic adenosine monophosphate (cAMP) and is involved in cAMP-mediated signal transduction through activation of the Ras-like small GTPase Rap. Crystallographic analyses revealed that activation of Epac2 by cAMP is accompanied by dynamic structural changes. Epac2 is expressed mainly in brain, neuroendocrine and endocrine tissues, and is involved in diverse cellular functions in the tissues. In this review, we summarize the structure and function of Epac2. We also discuss the physiological and pathophysiological roles of Epac2, and the possibility of Epac2 as a therapeutic target. PMID:26390815

  19. Role of PHOSPHO1 in Periodontal Development and Function.

    PubMed

    Zweifler, L E; Ao, M; Yadav, M; Kuss, P; Narisawa, S; Kolli, T N; Wimer, H F; Farquharson, C; Somerman, M J; Millán, J L; Foster, B L

    2016-07-01

    The tooth root and periodontal apparatus, including the acellular and cellular cementum, periodontal ligament (PDL), and alveolar bone, are critical for tooth function. Cementum and bone mineralization is regulated by factors including enzymes and extracellular matrix proteins that promote or inhibit hydroxyapatite crystal growth. Orphan Phosphatase 1 (Phospho1, PHOSPHO1) is a phosphatase expressed by chondrocytes, osteoblasts, and odontoblasts that functions in skeletal and dentin mineralization by initiating deposition of hydroxyapatite inside membrane-limited matrix vesicles. The role of PHOSPHO1 in periodontal formation remains unknown and we aimed to determine its functional importance in these tissues. We hypothesized that the enzyme would regulate proper mineralization of the periodontal apparatus. Spatiotemporal expression of PHOSPHO1 was mapped during periodontal development, and Phospho1(-/-) mice were analyzed using histology, immunohistochemistry, in situ hybridization, radiography, and micro-computed tomography. The Phospho1 gene and PHOSPHO1 protein were expressed by active alveolar bone osteoblasts and cementoblasts during cellular cementum formation. In Phospho1(-/-) mice, acellular cementum formation and mineralization were unaffected, whereas cellular cementum deposition increased although it displayed delayed mineralization and cementoid. Phospho1(-/-) mice featured disturbances in alveolar bone mineralization, shown by accumulation of unmineralized osteoid matrix and interglobular patterns of protein deposition. Parallel to other skeletal sites, deposition of mineral-regulating protein osteopontin (OPN) was increased in alveolar bone in Phospho1(-/-) mice. In contrast to the skeleton, genetic ablation of Spp1, the gene encoding OPN, did not ameliorate dentoalveolar defects in Phospho1(-/-) mice. Despite alveolar bone mineralization defects, periodontal attachment and function appeared undisturbed in Phospho1(-/-) mice, with normal PDL

  20. The Role of Impaired Epidermal Barrier Function in Atopic Dermatitis.

    PubMed

    Jurakić Tončić, Ružica; Marinović, Branka

    2016-06-01

    Atopic dermatitis (AD) is a chronic, inflammatory, pruritic skin disease with increasing prevalence. The etiopathogenesis of atopic dermatitis is multifactorial and involves a complex interplay of environmental and genetic factors that induce derangements in the structure and function of the epidermal barrier and immune system. Due to great heterogeneity of etiopathogenesis, there is also great variability of clinical presentation, and diagnosis can sometimes be challenging and difficult. Diagnosis mostly relies on clinical features and laboratory tests, but morphology alone cannot reliably establish the diagnosis, so the spectrum of features associated with AD must be considered. Traditionally, patients with AD have been separated into two different subgroups, i.e. intrinsic and extrinsic. Today, most of authors prefer the outside to inside and back to outside hypothesis, suggesting that the primary disorder lies in epidermal structure and function, resulting in inflammation and immunological downstream activation which further provokes secondary barrier abnormalities. In this review, we discuss the structure and function of the epidermal barrier and the role of impaired barrier function in etiopathogenesis of atopic dermatitis. PMID:27477169

  1. [Roles and functions of military flight nursing: aeromedical evacuation].

    PubMed

    Lee, Chun-Lan; Hsiao, Yun-Chien; Chen, Chao-Yen

    2012-06-01

    Evacuating the injured is an important part of disaster medicine. Aircraft provide timely access to distant and remote areas and, in an emergency, can evacuate sick or injured individuals in such areas quickly and safely for critical treatment elsewhere. Aeromedical evacuation (AE) comprises the two categories of fixed-wing ambulance service and helicopter emergency medical service (HEMS). Each aims to accomplish unique objectives. In Taiwan, the Second Taiwan Strait Crisis in 1958 established the unique role and functions of medical flight nursing. Significant knowledge and experience has been accumulated in the field since that time in such areas as the effects of high altitude environments on individuals and equipment; physiological, psychological, social and spiritual factors that affect the injured and / or response team members; and emergency care delivery techniques. All have been essential elements in the development and delivery of comprehensive medical flight nurse training. Medical flight nursing belongs in a special professional category, as nurses must master knowledge on general and special-case casualty evacuation procedures, relevant instruments and equipment, triage, in-flight medical care, and aircraft loading requirements related to transporting the sick and injured. The internationalization of medical care has opened the potential to expand medical flight nursing roles and functions into disaster nursing. Although military considerations continue to frame medical flight nursing training and preparation today, the authors feel that creating strategic alliances with disaster nursing specialists and organizations overseas is a future developmental direction for Taiwan's medical flight nursing sector worth formal consideration. PMID:22661029

  2. Movement dynamics reflect a functional role for weak coupling and role structure in dyadic problem solving.

    PubMed

    Abney, Drew H; Paxton, Alexandra; Dale, Rick; Kello, Christopher T

    2015-11-01

    Successful interaction requires complex coordination of body movements. Previous research has suggested a functional role for coordination and especially synchronization (i.e., time-locked movement across individuals) in different types of human interaction contexts. Although such coordination has been shown to be nearly ubiquitous in human interaction, less is known about its function. One proposal is that synchrony supports and facilitates communication (Topics Cogn Sci 1:305-319, 2009). However, questions still remain about what the properties of coordination for optimizing communication might look like. In the present study, dyads worked together to construct towers from uncooked spaghetti and marshmallows. Using cross-recurrence quantification analysis, we found that dyads with loosely coupled gross body movements performed better, supporting recent work suggesting that simple synchrony may not be the key to effective performance (Riley et al. 2011). We also found evidence that leader-follower dynamics-when sensitive to the specific role structure of the interaction-impact task performance. We discuss our results with respect to the functional role of coordination in human interaction. PMID:25757891

  3. Cytokines and macrophage function in humans - role of stress

    NASA Technical Reports Server (NTRS)

    Sonnenfeld, Gerald (Principal Investigator)

    1996-01-01

    We have begun this study to commence the determination of the role of mild chronic stress in the effects of space flight on macrophage/monocyte function, a component of the immune response. Medical students undergoing regular periods of stress and relaxation have been shown to be an excellent model for determining the effects of stress on immune responses. We have begun using this model using the macrophage/monocyte as model leukocyte. The monocyte/macrophage plays a central role in immunoregulation. The studies to be included in this three year project are the effects of stress on: (1) interactions of monocytes with microbes, (2) monocyte production of cytokines, (3) monocyte phagocytosis and activity, and (4) monocyte expression of cell surface antigens important in immune responses. Stress hormone levels will also be carried out to determine if there is a correlation between stress effects on immune responses and hormonal levels. Psychological testing to insure subjects are actually stressed or relaxed at the time of testing will also be carried out. The results obtained from the proposed studies should be comparable with space flight studies with whole animals and isolated cell cultures. When complete this study should allow the commencement of the establishment of the role of stress as one compartment of the induction of immune alterations by space flight.

  4. Resistin: functional roles and therapeutic considerations for cardiovascular disease

    PubMed Central

    Jamaluddin, Md S; Weakley, Sarah M; Yao, Qizhi; Chen, Changyi

    2012-01-01

    Resistin, originally described as an adipocyte-specific hormone, has been suggested to be an important link between obesity, insulin resistance and diabetes. Although its expression was initially defined in adipocytes, significant levels of resistin expression in humans are mainly found in mononuclear leukocytes, macrophages, spleen and bone marrow cells. Increasing evidence indicates that resistin plays important regulatory roles apart from its role in insulin resistance and diabetes in a variety of biological processes: atherosclerosis and cardiovascular disease (CVD), non-alcoholic fatty liver disease, autoimmune disease, malignancy, asthma, inflammatory bowel disease and chronic kidney disease. As CVD accounts for a significant amount of morbidity and mortality in patients with diabetes and without diabetes, it is important to understand the role that adipokines such as resistin play in the cardiovascular system. Evidence suggests that resistin is involved in pathological processes leading to CVD including inflammation, endothelial dysfunction, thrombosis, angiogenesis and smooth muscle cell dysfunction. The modes of action and signalling pathways whereby resistin interacts with its target cells are beginning to be understood. In this review, the current knowledge about the functions and pathophysiological implications of resistin in CVD development is summarized; clinical translations, therapeutic considerations and future directions in the field of resistin research are discussed. LINKED ARTICLES This article is part of a themed section on Fat and Vascular Responsiveness. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-3 PMID:21545576

  5. Fungal chitinases: function, regulation, and potential roles in plant/pathogen interactions.

    PubMed

    Langner, Thorsten; Göhre, Vera

    2016-05-01

    In the past decades our knowledge about fungal cell wall architecture increased tremendously and led to the identification of many enzymes involved in polysaccharide synthesis and remodeling, which are also of biotechnological interest. Fungal cell walls play an important role in conferring mechanic stability during cell division and polar growth. Additionally, in phytopathogenic fungi the cell wall is the first structure that gets into intimate contact with the host plant. A major constituent of fungal cell walls is chitin, a homopolymer of N-acetylglucosamine units. To ensure plasticity, polymeric chitin needs continuous remodeling which is maintained by chitinolytic enzymes, including lytic polysaccharide monooxygenases N-acetylglucosaminidases, and chitinases. Depending on the species and lifestyle of fungi, there is great variation in the number of encoded chitinases and their function. Chitinases can have housekeeping function in plasticizing the cell wall or can act more specifically during cell separation, nutritional chitin acquisition, or competitive interaction with other fungi. Although chitinase research made huge progress in the last decades, our knowledge about their role in phytopathogenic fungi is still scarce. Recent findings in the dimorphic basidiomycete Ustilago maydis show that chitinases play different physiological functions throughout the life cycle and raise questions about their role during plant-fungus interactions. In this work we summarize these functions, mechanisms of chitinase regulation and their putative role during pathogen/host interactions. PMID:26527115

  6. Meaning and Function of Dummy Auxiliaries in Adult Acquisition of Dutch as an Additional Language

    ERIC Educational Resources Information Center

    Julien, Manuela; van Hout, Roeland; van de Craats, Ineke

    2016-01-01

    This article presents the results of experimental data on language production and comprehension. These show that adult learners of Dutch as an additional language, with different language backgrounds, and a L2 proficiency below level A2 (Waystage) of the Common European Framework of Reference for Languages (CEFR; Council of Europe, 2001), use…

  7. Molecular aspects of aromatic C additions to soils: Implications of biochar quality for ecosystem functionality

    EPA Science Inventory

    Solid residues of incomplete combustion (biochar or char) are continuously being added to soils due to natural vegetation fires in many ecosystems. However, new strategies for carbon sequestration in soils are likely to include the active addition of biochar to soils. Since bioc...

  8. Functional roles of HIV-1 Tat protein in the nucleus.

    PubMed

    Musinova, Yana R; Sheval, Eugene V; Dib, Carla; Germini, Diego; Vassetzky, Yegor S

    2016-02-01

    Human immunodeficiency virus-1 (HIV-1) Tat protein is one of the most important regulatory proteins for viral gene expression in the host cell and can modulate different cellular processes. In addition, Tat is secreted by the infected cell and can be internalized by neighboring cells; therefore, it affects both infected and uninfected cells. Tat can modulate cellular processes by interacting with different cellular structures and signaling pathways. In the nucleus, Tat might be localized either in the nucleoplasm or the nucleolus depending on its concentration. Here we review the distinct functions of Tat in the nucleoplasm and the nucleolus in connection with viral infection and HIV-induced oncogenesis. PMID:26507246

  9. Function-Biased Choice of Additives for Optimization of Protein Crystallization: The Case of the Putative Thioesterase PA5185 from Pseudomonas aeruginosa PAO1

    SciTech Connect

    Chruszcz, Maksymilian; Zimmerman, Matthew D.; Wang, Shuren; Koclega, Katarzyna D.; Zheng, Heping; Evdokimova, Elena; Kudritska, Marina; Cymborowski, Marcin; Savchenko, Alexei; Edwards, Aled; Minor, Wladek

    2009-09-15

    The crystal structure of PA5185, a putative thioesterase from Pseudomonas aeruginosa strain PAO1, was solved using multi-wavelength anomalous diffraction to 2.4 {angstrom}. Analysis of the structure and information about the putative function of the protein were used to optimize crystallization conditions. The crystal growth was optimized by applying additives with chemical similarity to a fragment of a putative PA5185 substrate (CoA or its derivative). Using new crystallization conditions containing this function-biased set of additives, several new crystal forms were produced, and structures of three of them (in three different space groups) were determined. One of the new crystal forms had an improved resolution limit of 1.9 {angstrom}, and another displayed an alternative conformation of the highly conserved loop containing Asn26, which could play a physiological role. Surprisingly, none of the additives were ordered in the crystal structures. Application of function-biased additives could be used as a standard optimization protocol for producing improved diffraction, or new crystal forms, which may lead to better understanding of the biological functions of proteins.

  10. Protomer Roles in Chloroplast Chaperonin Assembly and Function.

    PubMed

    Bai, Cuicui; Guo, Peng; Zhao, Qian; Lv, Zongyang; Zhang, Shijia; Gao, Fei; Gao, Liyan; Wang, Yingchun; Tian, Zhixi; Wang, Jifeng; Yang, Fuquan; Liu, Cuimin

    2015-10-01

    The individual roles of three chloroplast CPN60 protomers (CPN60α, CPN60β1, and CPN60β2) and whether and how they are assembled into functional chaperonin complexes are investigated in Chlamydomonas reinhardtii. Protein complexes containing all three potential subunits were identified in Chlamydomonas, and their co-expression in Escherichia coli yielded a homogeneous population of oligomers containing all three subunits (CPN60αβ1β2), with a molecular weight consistent with a tetradecameric structure. While homo-oligomers of CPN60β could form, they were dramatically reduced when CPN60α was present and homo-oligomers of CPN60β2 were readily changed into hetero-oligomers in the presence of ATP and other protomers. ATP hydrolysis caused CPN60 oligomers to disassemble and drove the purified protomers to reconstitute oligomers in vitro, suggesting that the dynamic nature of CPN60 oligomers is dependent on ATP. Only hetero-oligomeric CPN60αβ1β2, containing CPN60α, CPN60β1, and CPN60β2 subunits in a 5:6:3 ratio, cooperated functionally with GroES. The combination of CPN60α and CPN60β subunits, but not the individual subunits alone, complemented GroEL function in E. coli with subunit recognition specificity. Down-regulation of the CPN60α subunit in Chlamydomonas resulted in a slow growth defect and an inability to grow autotrophically, indicating the essential role of CPN60α in vivo. PMID:26057234

  11. Addition of Functional Content during Core Content Instruction with Students with Moderate Disabilities

    ERIC Educational Resources Information Center

    Collins, Belva C.; Hager, Karen L.; Galloway, Carey Creech

    2011-01-01

    The purpose of this investigation was to add functional content during core content instruction of language arts, science, and math. The investigation involved three middle school students with moderate disabilities who participated in the state's alternate assessment. During instruction using a constant time delay procedure to teach required…

  12. Using Additional Analyses to Clarify the Functions of Problem Behavior: An Analysis of Two Cases

    ERIC Educational Resources Information Center

    Payne, Steven W.; Dozier, Claudia L.; Neidert, Pamela L.; Jowett, Erica S.; Newquist, Matthew H.

    2014-01-01

    Functional analyses (FA) have proven useful for identifying contingencies that influence problem behavior. Research has shown that some problem behavior may only occur in specific contexts or be influenced by multiple or idiosyncratic variables. When these contexts or sources of influence are not assessed in an FA, further assessment may be…

  13. Oxalic Acid Has an Additional, Detoxifying Function in Sclerotinia sclerotiorum Pathogenesis

    PubMed Central

    Heller, Annerose; Witt-Geiges, Tanja

    2013-01-01

    The mechanism of the diseases caused by the necrotroph plant pathogen Sclerotinia sclerotiorum is not well understood. To investigate the role of oxalic acid during infection high resolution, light-, scanning-, transmission electron microscopy and various histochemical staining methods were used. Our inoculation method allowed us to follow degradation of host plant tissue around single hyphae and to observe the reaction of host cells in direct contact with single invading hyphae. After penetration the outer epidermal cell wall matrix appeared degraded around subcuticular hyphae (12-24 hpi). Calcium oxalate crystals were detected in advanced (36-48 hpi) and late (72 hpi) infection stages, but not in early stages. In early infection stages, surprisingly, no toxic effect of oxalic acid eventually secreted by S. sclerotiorum was observed. As oxalic acid is a common metabolite in plants, we propose that attacked host cells are able to metabolize oxalic acid in the early infection stage and translocate it to their vacuoles where it is stored as calcium oxalate. The effects, observed on healthy tissue upon external application of oxalic acid to non-infected, living tissue and cell wall degradation of dead host cells starting at the inner side of the walls support this idea. The results indicate that oxalic acid concentrations in the early stage of infection stay below the toxic level. In plant and fungi oxalic acid/calcium oxalate plays an important role in calcium regulation. Oxalic acid likely could quench calcium ions released during cell wall breakdown to protect growing hyphae from toxic calcium concentrations in the infection area. As calcium antimonate-precipitates were found in vesicles of young hyphae, we propose that calcium is translocated to the older parts of hyphae and detoxified by building non-toxic, stable oxalate crystals. We propose an infection model where oxalic acid plays a detoxifying role in late infection stages. PMID:23951305

  14. Role of cysteines in mammalian VDAC isoforms' function.

    PubMed

    De Pinto, Vito; Reina, Simona; Gupta, Ankit; Messina, Angela; Mahalakshmi, Radhakrishnan

    2016-08-01

    In this mini-review, we analyze the influence of cysteines in the structure and activity of mitochondrial outer membrane mammalian VDAC isoforms. The three VDAC isoforms show conserved sequences, similar structures and the same gene organization. The meaning of three proteins encoded in different chromosomes must thus be searched for subtle differences at the amino acid level. Among others, cysteine content is noticeable. In humans, VDAC1 has 2, VDAC2 has 9 and VDAC3 has 6 cysteines. Recent works have shown that, at variance from VDAC1, VDAC2 and VDAC3 exhibit cysteines predicted to protrude towards the intermembrane space, making them a preferred target for oxidation by ROS. Mass spectrometry in VDAC3 revealed that a disulfide bridge can be formed and other cysteine oxidations are also detectable. Both VDAC2 and VDAC3 cysteines were mutagenized to highlight their role in vitro and in complementation assays in Δporin1 yeast. Chemico-physical techniques revealed an important function of cysteines in the structural stabilization of the pore. In conclusion, the works available on VDAC cysteines support the notion that the three proteins are paralogs with a similar pore-function and slightly different, but important, ancillary biological functions. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi. PMID:26947058

  15. Metal-Catalyzed β-Functionalization of Michael Acceptors through Reductive Radical Addition Reactions.

    PubMed

    Streuff, Jan; Gansäuer, Andreas

    2015-11-23

    Transition-metal-catalyzed radical reactions are becoming increasingly important in modern organic chemistry. They offer fascinating and unconventional ways for connecting molecular fragments that are often complementary to traditional methods. In particular, reductive radical additions to α,β-unsaturated compounds have recently gained substantial attention as a result of their broad applicability in organic synthesis. This Minireview critically discusses the recent landmark achievements in this field in context with earlier reports that laid the foundation for today's developments. PMID:26471460

  16. Covalent addition of chitosan to graphene sheets: Density functional theory explorations of quadrupole coupling constants

    NASA Astrophysics Data System (ADS)

    Mokhtari, Ali; Harismah, Kun; Mirzaei, Mahmoud

    2015-12-01

    Density functional theory (DFT) calculations have been performed to detect the stabilities and properties of chitosan-functionalized graphene and graphene-oxide structures (G-Chit and GO-Chit). The model systems with two different sizes of sheets have been optimized and the molecular and atomic properties have been evaluated for them. The results indicated that investigated G-Chit and GO-Chit structures could be considered as stable structures but with different properties. The properties for GO and GO-Chit structures are almost similar; however, they are different from the original G and G-Chit structures. The results also indicated that the properties could be also size-dependent, in which different molecular and atomic properties have been observed for the investigate G sheets.

  17. Additive, modular functionalization of reactive self-assembled monolayers: toward the fabrication of multilevel optical storage media

    NASA Astrophysics Data System (ADS)

    Gentili, Denis; Barbalinardo, Marianna; Manet, Ilse; Durso, Margherita; Brucale, Marco; Mezzi, Alessio; Melucci, Manuela; Cavallini, Massimiliano

    2015-04-01

    We report a novel strategy based on iterative microcontact printing, which provides additive, modular functionalization of reactive SAMs by different functional molecules. We demonstrate that after printing the molecules form an interpenetrating network at the SAM surface preserving their individual properties. We exploited the process by fabricating new optical storage media that consist of a multilevel TAG.We report a novel strategy based on iterative microcontact printing, which provides additive, modular functionalization of reactive SAMs by different functional molecules. We demonstrate that after printing the molecules form an interpenetrating network at the SAM surface preserving their individual properties. We exploited the process by fabricating new optical storage media that consist of a multilevel TAG. Electronic supplementary information (ESI) available: Experimental details, synthesis and characterization of compounds 1, 2, 1-Sil and 2-Sil, and materials. See DOI: 10.1039/c5nr00346f

  18. Family Functioning and Dysfunctional Eating Among Italian Adolescents: The Moderating Role of Gender.

    PubMed

    Laghi, Fiorenzo; McPhie, Meghan L; Baumgartner, Emma; Rawana, Jennine S; Pompili, Sara; Baiocco, Roberto

    2016-02-01

    The first aim of this study was to examine the association between different dimensions of family functioning and dysfunctional eating in a sample of Italian adolescent boys and girls. The second aim was to investigate whether gender moderates the relationship between family functioning and dysfunctional eating. Seven hundred and twenty seven adolescents (500 boys and 227 girls) with ages ranging from 15 to 18 years completed a survey of self-report measures. Findings from hierarchical multiple regression analysis suggested that aspects of family functioning such as flexibility, cohesion, disengagement, enmeshment, rigidity and chaotic were related to dysfunctional eating in adolescents. Additionally the results indicated differences between boys and girls, in particular dysfunctional eating in adolescent boys seemed to be more affected by dimensions of enmeshment and disengagement than dysfunctional eating in girls. This research highlights the important role of various aspects of family functioning in relation to dysfunctional eating in adolescents. PMID:25776344

  19. The Role of Control Functions in Mentalizing: Dual-Task Studies of Theory of Mind and Executive Function

    ERIC Educational Resources Information Center

    Bull, Rebecca; Phillips, Louise H.; Conway, Claire A.

    2008-01-01

    Conflicting evidence has arisen from correlational studies regarding the role of executive control functions in Theory of Mind. The current study used dual-task manipulations of executive functions (inhibition, updating and switching) to investigate the role of these control functions in mental state and non-mental state tasks. The "Eyes"…

  20. T follicular helper cell differentiation, function, and roles in disease

    PubMed Central

    Crotty, Shane

    2014-01-01

    Summary Follicular helper T (Tfh) cells are specialized providers of T cell help to B cells, and are essential for germinal center formation, affinity maturation, and the development of most high affinity antibodies and memory B cells. Tfh cell differentiation is a multi-stage, multi-factorial process involving B cell lymphoma 6 (Bcl6) and other transcription factors. This article reviews understanding of Tfh cell biology, including their differentiation, migration, transcriptional regulation, and B cell help functions. Tfh cells are critical components of many protective immune responses against pathogens. As such, there is strong interest in harnessing Tfh cells to improve vaccination strategies. Tfh cells also have roles in a range of other diseases, particularly autoimmune diseases. Overall, there have been dramatic advances in this young field, but there is much to be learned about Tfh cell biology in the interest of applying that knowledge to biomedical needs. PMID:25367570

  1. Versatile Roles of V-ATPases Accessory Subunit Ac45 in Osteoclast Formation and Function

    PubMed Central

    Lin, Zhen; Pavlos, Nathan J.; Jiang, Qing; Xu, Jiake; Dai, Ke R.; Zheng, Ming H.

    2011-01-01

    Vacuolar-type H+-ATPases (V-ATPases) are macromolecular proton pumps that acidify intracellular cargos and deliver protons across the plasma membrane of a variety of specialized cells, including bone-resorbing osteoclasts. Extracellular acidification is crucial for osteoclastic bone resorption, a process that initiates the dissolution of mineralized bone matrix. While the importance of V-ATPases in osteoclastic resorptive function is well-defined, whether V-ATPases facilitate additional aspects of osteoclast function and/or formation remains largely obscure. Here we report that the V-ATPase accessory subunit Ac45 participates in both osteoclast formation and function. Using a siRNA-based approach, we show that targeted suppression of Ac45 impairs intracellular acidification and endocytosis, both are prerequisite for osteoclastic bone resorptive function in vitro. Interestingly, we find that knockdown of Ac45 also attenuates osteoclastogenesis owing to a reduced fusion capacity of osteoclastic precursor cells. Finally, in an effort to gain more detailed insights into the functional role of Ac45 in osteoclasts, we attempted to generate osteoclast-specific Ac45 conditional knockout mice using a Cathepsin K-Cre-LoxP system. Surprisingly, however, insertion of the neomycin cassette in the Ac45-FloxNeo mice resulted in marked disturbances in CNS development and ensuing embryonic lethality thus precluding functional assessment of Ac45 in osteoclasts and peripheral bone tissues. Based on these unexpected findings we propose that, in addition to its canonical function in V-ATPase-mediated acidification, Ac45 plays versatile roles during osteoclast formation and function. PMID:22087256

  2. Role of glutathione transport processes in kidney function

    SciTech Connect

    Lash, Lawrence H. . E-mail: l.h.lash@wayne.edu

    2005-05-01

    The kidneys are highly dependent on an adequate supply of glutathione (GSH) to maintain normal function. This is due, in part, to high rates of aerobic metabolism, particularly in the proximal tubules. Additionally, the kidneys are potentially exposed to high concentrations of oxidants and reactive electrophiles. Renal cellular concentrations of GSH are maintained by both intracellular synthesis and transport from outside the cell. Although function of specific carriers has not been definitively demonstrated, it is likely that multiple carriers are responsible for plasma membrane transport of GSH. Data suggest that the organic anion transporters OAT1 and OAT3 and the sodium-dicarboxylate 2 exchanger (SDCT2 or NaDC3) mediate uptake across the basolateral plasma membrane (BLM) and that the organic anion transporting polypeptide OATP1 and at least one of the multidrug resistance proteins mediate efflux across the brush-border plasma membrane (BBM). BLM transport may be used pharmacologically to provide renal proximal tubular cells with exogenous GSH to protect against oxidative stress whereas BBM transport functions physiologically in turnover of cellular GSH. The mitochondrial GSH pool is derived from cytoplasmic GSH by transport into the mitochondrial matrix and is mediated by the dicarboxylate and 2-oxoglutarate exchangers. Maintenance of the mitochondrial GSH pool is critical for cellular and mitochondrial redox homeostasis and is important in determining susceptibility to chemically induced apoptosis. Hence, membrane transport processes are critical to regulation of renal cellular and subcellular GSH pools and are determinants of susceptibility to cytotoxicity induced by oxidants and electrophiles.

  3. On the function and homeostasis of PCSK9: reciprocal interaction with LDLR and additional lipid effects.

    PubMed

    Tavori, Hagai; Rashid, Shirya; Fazio, Sergio

    2015-02-01

    Proprotein convertase subtilisin kexin type 9 (PCSK9) is a circulatory ligand that terminates the lifecycle of the low-density lipoprotein (LDL) receptor (LDLR) thus affecting plasma LDL-cholesterol (LDL-C) levels. Recent evidence shows that in addition to the straightforward mechanism of action, there are more complex interactions between PCSK9, LDLR and plasma lipoprotein levels, including: (a) the presence of both parallel and reciprocal regulation of surface LDLR and plasma PCSK9; (b) a correlation between PCSK9 and LDL-C levels dependent not only on the fact that PCSK9 removes hepatic LDLR, but also due to the fact that up to 40% of plasma PCSK9 is physically associated with LDL; and (c) an association between plasma PCSK9 production and the assembly and secretion of triglyceride-rich lipoproteins. The effect of PCSK9 on LDLR is being successfully utilized toward the development of anti-PCSK9 therapies to reduce plasma LDL-C levels. Current biochemical research has uncovered additional mechanisms of action and interacting partners for PCSK9, and this opens the way for a more thorough understanding of the regulation, metabolism, and effects of this interesting protein. PMID:25544176

  4. Structures and Functions of Oligosaccharins: The Role of Endoglycanases

    SciTech Connect

    Bergmann, Carl W.

    2008-12-05

    The research proposed will investigate two projects that involve studies of the chemistry and biology of protein/protein and protein/carbohydrate interactions involved in host/pathogen interactions. Specifically, the projects involve (i) the interactions between fungal endopolygalacturonases and plant polygalacturonase-inhibiting proteins and (ii) the interactions between fungal endoxylanases and plant arabinoxylans. During pathogenesis fungi secrete families of endoglycanases that fragment the cell wall polysaccharides of the plant host. The result of endoglycanase action on cell wall polysaccharides can include weakening of the wall, penetration of host cells by the pathogen, solubilization of carbohydrate nutrients, and formation of oligosaccharins (oligosaccharides with regulatory function) that can stimulate plant defenses. We have made significant advances during the last funding period to support the hypothesis that the outcome of attempted pathogenesis can be influenced by protein/protein and protein/carbohydrate interactions in the extracellular matrices of the host and pathogen. We plan to expand on those successes by further exploring the mechanism of action of the endoglycanases and their plant-derived inhibitors, the expression of the various members of the endoglycanase families at various stages of infection and their role in the release of oligosaccharins and in pathogenicity, as well as the role played by the polysaccharide substrates in both pathogenicity and endoglycanase-inhibitor interactions.

  5. Functional role, structure, and evolution of the melanocortin-4 receptor.

    PubMed

    Schiöth, Helgi B; Lagerström, Malin C; Watanobe, Hajime; Jonsson, Logi; Vergoni, Anna Valeria; Ringholm, Aneta; Skarphedinsson, Jon O; Skuladottir, Gudrun V; Klovins, Janis; Fredriksson, Robert

    2003-06-01

    The melanocortin (MC)-4 receptor participates in regulating body weight homeostasis. We demonstrated early that acute blockage of the MC-4 receptor increases food intake and relieves anorexic conditions in rats. Our recent studies show that 4-week chronic blockage of the MC-4 receptor leads to robust increases in food intake and development of obesity, whereas stimulation of the receptor leads to anorexia. Interestingly, the food conversion ratio was clearly increased by MC-4 receptor blockage, whereas it was decreased in agonist-treated rats in a transient manner. Chronic infusion of an agonist caused a transient increase in oxygen consumption. Our studies also show that the MC-4 receptor plays a role in luteinizing hormone and prolactin surges in female rats. The MC-4 receptor has a role in mediating the effects of leptin on these surges. The phylogenetic relation of the MC-4 receptor to other GPCRs in the human genome was determined. The three-dimensional structure of the protein was studied by construction of a high-affinity zinc binding site between the helices, using two histidine residues facing each other. We also cloned the MC-4 receptor from evolutionary important species and showed by chromosomal mapping a conserved synteny between humans and zebrafish. The MC-4 receptor has been remarkably conserved in structure and pharmacology for more than 400 million years, implying that the receptor participated in vital physiological functions early in vertebrate evolution. PMID:12851300

  6. The mechanism of alkene addition to a nickel bis(dithiolene) complex: the role of the reduced metal complex.

    PubMed

    Dang, Li; Shibl, Mohamed F; Yang, Xinzheng; Alak, Aiman; Harrison, Daniel J; Fekl, Ulrich; Brothers, Edward N; Hall, Michael B

    2012-03-14

    The binding of an alkene by Ni(tfd)(2) [tfd = S(2)C(2)(CF(3))(2)] is one of the most intriguing ligand-based reactions. In the presence of the anionic, reduced metal complex, the primary product is an interligand adduct, while in the absence of the anion, dihydrodithiins and metal complex decomposition products are preferred. New kinetic (global analysis) and computational (DFT) data explain the crucial role of the anion in suppressing decomposition and catalyzing the formation of the interligand product through a dimetallic complex that appears to catalyze alkene addition across the Ni-S bond, leading to a lower barrier for the interligand adduct. PMID:22364208

  7. Pyruvate kinase: function, regulation and role in cancer

    PubMed Central

    Israelsen, William J.; Vander Heiden, Matthew G.

    2015-01-01

    Pyruvate kinase is an enzyme that catalyzes the conversion of phosphoenolpyruvate and ADP to pyruvate and ATP in glycolysis and plays a role in regulating cell metabolism. There are four mammalian pyruvate kinase isoforms with unique tissue expression patterns and regulatory properties. The M2 isoform of pyruvate kinase (PKM2) supports anabolic metabolism and is expressed both in cancer and normal tissue. The enzymatic activity of PKM2 is allosterically regulated by both intracellular signaling pathways and metabolites; PKM2 thus integrates signaling and metabolic inputs to modulate glucose metabolism according to the needs of the cell. Recent advances have increased our understanding of metabolic regulation by pyruvate kinase, raised new questions, and suggested the possibility of non-canonical PKM2 functions to regulate gene expression and cell cycle progression via protein-protein interactions and protein kinase activity. Here we review the structure, function, and regulation of pyruvate kinase and discuss how these properties enable regulation of PKM2 for cell proliferation and tumor growth. PMID:26277545

  8. Multi-Walled Carbon Nanotube Functionalization by Radical Addition Using Hydroxymethylene Groups.

    PubMed

    Rodríguez-Jiménez, Rubén; Alonso-Núñez, Gabriel; Paraguay-Delgado, Francisco; Espinoza-Gómez, Heriberto; Vélez-López, Ernesto; Rogel-Hernández, Eduardo

    2016-01-01

    Synthetic methodology and characterization of multi-walled carbon nanotubes (MWCNTs) function- alized with hydroxymethylene groups are reported. The MWCNTs were synthesized by the spray pyrolysis technique using toluene as carbon source and ferrocene as catalyst. Hydroxymethylation of MWCNTs was carried out by methanol using benzoyl peroxide (BPO) at different quantities (300 to 900 mg); the optimum BPO quantity was 300 mg. The resulting materials were characterized by FT-IR, Raman Spectroscopy, Thermal Gravimetric Analysis (TGA) and Transmission Electron Microscopy (TEM). The presence of the hydroxymethylene group on the MWCNTs surface was demonstrated by FT-IR, Raman Spectroscopy, TGA, EDS, TEM and Mass Spectrometry. The func- tionalized MWCNTs were not damaged by this methodology. PMID:27398563

  9. Organic-inorganic hybrid foams with diatomite addition: Effect on functional properties

    NASA Astrophysics Data System (ADS)

    Verdolotti, L.; D'Auria, M.; Lavorgna, M.; Vollaro, P.; Iannace, S.; Capasso, I.; Galzerano, B.; Caputo, D.; Liguori, B.

    2016-05-01

    Organic-inorganic hybrid foams were prepared by using metakaolin, diatomite as a partial (or total) replacement of metakaolin, as matrix, silicon and whipped protein as pore forming. The foamed systems were hardened at defined temperature and time and then characterized by mechanical point of view through compression tests and by functional point of view through fire reaction and acoustic tests. The experimental findings highlighted that the replacement of diatomite in the formulation affected the morphological structure of the foams and consequently their mechanical properties. In particular, the consolidation mechanism in the diatomite based-hybrid foams changed from geopolymerization to a silicate polycondensation mechanism. Therefore, mechanical performances enhanced with increasing of the diatomite content. Fire reaction tests, such as non-combustibility and cone calorimeter tests, showed positive thermal inertia of samples regardless of the content of diatomite.

  10. Novel expression and functional role of ghrelin in chicken ovary.

    PubMed

    Sirotkin, A V; Grossmann, R; María-Peon, M T; Roa, J; Tena-Sempere, M; Klein, S

    2006-09-26

    Ghrelin has recently emerged as pleiotropic regulator of a wide array of endocrine and non-endocrine functions. The former likely includes the control of gonadal function, as expression of ghrelin and its putative receptor, the GH secretagogue receptor type 1a (GHS-R1a), has been described in mammalian gonads, and direct effects of ghrelin in the control of testicular secretion and cell proliferation have been reported. Yet, the expression and/or functional role of ghrelin in gonads from non-mammalian species remain to be analyzed. The present study aimed to evaluate the expression of ghrelin and GHS-R genes in the chicken ovary, and to assess the potential involvement of ghrelin in the direct control of chick ovarian function. To this end, RT-PCR assays for ghrelin and GHS-R1a mRNAs were performed in ovarian tissue, and cultures of chicken ovarian cells were conducted in the presence of increasing doses (1, 10 or 100 ng/ml) of the ghrelin analog, ghrelin 1-18. Our results demonstrate that both ghrelin and GHS-R1a mRNAs are expressed in chick ovarian tissue. Moreover, challenge of ovarian granulosa cells with ghrelin 1-18 was able to induce markers of proliferation (i.e. expression of both PCNA and cyclin), and to modulate markers of apoptosis (i.e. decreased expression of caspase-3, bax, bcl-2 and TUNEL-positive cells). Moreover, ghrelin 1-18 increased the expression of PCNA, cyclin, bax and p53 in cultures of ovarian follicular fragments, where it also stimulated the release of progesterone, estradiol, arginine-vasotocin (AVT) and IGF-I, but not of testosterone. In conclusion, our study provides novel evidence for the gonadal expression of the genes encoding ghrelin and its cognate receptor in a non-mammalian species, i.e. the chicken ovary, and unravels the potential involvement of this newly discovered molecule in the control of key gonadal functions in the chick, such as proliferation, apoptosis, and hormone release. PMID:16891055

  11. Is the structural diversity of tripeptides sufficient for developing functional food additives with satisfactory multiple bioactivities?

    NASA Astrophysics Data System (ADS)

    Wang, Jian-Hui; Liu, Yong-Le; Ning, Jing-Heng; Yu, Jian; Li, Xiang-Hong; Wang, Fa-Xiang

    2013-05-01

    Multifunctional peptides have attracted increasing attention in the food science community because of their therapeutic potential, low toxicity and rapid intestinal absorption. However, previous study demonstrated that the limited structural variations make it difficult to optimize dipeptide molecules in a good balance between desirable and undesirable properties (F. Tian, P. Zhou, F. Lv, R. Song, Z. Li, J. Pept. Sci. 13 (2007) 549-566). In the present work, we attempt to answer whether the structural diversity is sufficient for a tripeptide to have satisfactory multiple bioactivities. Statistical test, structural examination and energetic analysis confirm that peptides of three amino acids long can bind tightly to human angiotensin converting enzyme (ACE) and thus exert significant antihypertensive efficacy. Further quantitative structure-activity relationship (QSAR) modeling and prediction of all 8000 possible tripeptides reveal that their ACE-inhibitory potency exhibits a good (positive) relationship to antioxidative activity, but has only a quite modest correlation with bitterness. This means that it is possible to find certain tripeptide entities possessing the optimal combination of strong ACE-inhibitory potency, high antioxidative activity and weak bitter taste, which are the promising candidates for developing multifunctional food additives with satisfactory multiple bioactivities. The marked difference between dipeptide and tripeptide can be attributed to the fact that the structural diversity of peptides increases dramatically with a slight change in sequence length.

  12. Titanium-Based Hip Stems with Drug Delivery Functionality through Additive Manufacturing.

    PubMed

    Bezuidenhout, Martin B; Dimitrov, Dimitar M; van Staden, Anton D; Oosthuizen, Gert A; Dicks, Leon M T

    2015-01-01

    Postoperative infections are a major concern in patients that receive implants. These infections generally occur in areas with poor blood flow and pathogens do not always respond to antibiotic treatment. With the latest developments in nanotechnology, the incorporation of antibiotics into prosthetic implants may soon become a standard procedure. The success will, however, depend on the ability to control the release of antibiotics at concentrations high enough to prevent the development of antibiotic-resistant strains. Through additive manufacturing, antibiotics can be incorporated into cementless femoral stems to produce prosthetic devices with antimicrobial properties. With the emerging increase in resistance to antibiotics, the incorporation of antimicrobial compounds other than antibiotics, preferably drugs with a broader spectrum of antimicrobial activity, will have to be explored. This review highlights the microorganisms associated with total hip arthroplasty (THA), discusses the advantages and disadvantages of the latest materials used in hip implants, compares different antimicrobial agents that could be incorporated, and addresses novel ideas for future research. PMID:26504776

  13. Titanium-Based Hip Stems with Drug Delivery Functionality through Additive Manufacturing

    PubMed Central

    Bezuidenhout, Martin B.; Dimitrov, Dimitar M.; van Staden, Anton D.; Oosthuizen, Gert A.; Dicks, Leon M. T.

    2015-01-01

    Postoperative infections are a major concern in patients that receive implants. These infections generally occur in areas with poor blood flow and pathogens do not always respond to antibiotic treatment. With the latest developments in nanotechnology, the incorporation of antibiotics into prosthetic implants may soon become a standard procedure. The success will, however, depend on the ability to control the release of antibiotics at concentrations high enough to prevent the development of antibiotic-resistant strains. Through additive manufacturing, antibiotics can be incorporated into cementless femoral stems to produce prosthetic devices with antimicrobial properties. With the emerging increase in resistance to antibiotics, the incorporation of antimicrobial compounds other than antibiotics, preferably drugs with a broader spectrum of antimicrobial activity, will have to be explored. This review highlights the microorganisms associated with total hip arthroplasty (THA), discusses the advantages and disadvantages of the latest materials used in hip implants, compares different antimicrobial agents that could be incorporated, and addresses novel ideas for future research. PMID:26504776

  14. Improvement of attenuation functions of a clayey sandstone for landfill leachate containment by bentonite addition.

    PubMed

    Ruiz, Ana I; Fernández, Raúl; Sánchez Jiménez, Nicanor; Rodríguez Rastrero, Manuel; Regadío, Mercedes; de Soto, Isabel S; Cuevas, Jaime

    2012-03-01

    Enhanced sand-clay mixtures have been prepared by using a sandstone arkosic material and have been evaluated for consideration as landfill liners. A lab-scale test was carried out under controlled conditions with different amended natural sandstones whereby leachate was passed through the compacted mixtures. The compacted samples consisted of siliceous sand (quartz-feldspar sand separated from the arkose sandstone) and clay (purified clay from arkose sandstone and two commercial bentonites) materials that were mixed in different proportions. The separation of mineral materials from a common and abundant natural source, for soil protection purposes, is proposed as an economic and environmentally efficient practice. The liner qualities were compared for their mineralogical, physicochemical and major ions transport and adsorption properties. Although all samples fulfilled hydraulic conductivity requirements, the addition of bentonite to arkose sandstone was determined to be an effective strategy to decrease the permeability of the soil and to improve the pollutants retention. The clay materials from arkose sandstone also contributed to pollutant retention by a significant improvement of the cation exchange capacity of the bulk material. However, the mixtures prepared with clay materials from the arkose, exhibited a slight increase of hydraulic conductivity. This effect has to be further evaluated. PMID:22285080

  15. Effects of Germinated Brown Rice Addition on the Flavor and Functionality of Yogurt

    PubMed Central

    2016-01-01

    This study aimed to investigate the functional and physicochemical properties of yogurt, supplemented with germinated brown rice (GBR) containing γ-aminobutyric acid (GABA), during storage. GBR was produced by soaking brown rice at 30℃, and saccharified germinated brown rice (SGBR) was produced by treating brown rice with α- and β-amylase for 1 h, at 80℃ and 60℃, respectively. Yogurt was manufactured using a commercial starter (YC-X11, CHR. Hansen, Denmark) at 37℃ for 12 h. The fatty acids and GABA contents were analyzed using GC and HPLC, respectively. The fatty acids in the cereal samples consisted of oleic, linoleic, and palmitic acid. The portion of oleic acid was the highest, at 35.65% in GBR, and 32.16% in SGBR. During germination, the oleic acid content increased, whereas linolenic and palmitic acid contents from GBR tended to decrease. Although the portion of saturated fatty acids, such as stearic and myristic acid, decreased significantly (p<0.05), that of unsaturated fatty acids, such as oleic and linoleic acid, increased with an increase in supplementation of BR, GBR, or SGBR in the yogurt. The yogurt, supplemented with cereal samples, showed a tendency of an increase in the concentration of GABA with an increase in the supplementation of the cereal samples. However, yogurt supplemented with GBR showed the highest concentration of GABA, regardless of the supplementation of the cereal samples. These results indicated that yogurt supplemented with BR, GBR, or SGBR could be a promising dairy product. PMID:27621692

  16. Role of cysteine residues in regulation of p53 function.

    PubMed

    Rainwater, R; Parks, D; Anderson, M E; Tegtmeyer, P; Mann, K

    1995-07-01

    Previous studies of p53 have implicated cysteine residues in site-specific DNA binding via zinc coordination and redox regulation (P. Hainaut and J. Milner, Cancer Res. 53:4469-4473, 1993; T. R. Hupp, D. W. Meek, C. A. Midgley, and D. P. Lane, Nucleic Acids Res. 21:3167-3174, 1993). We show here that zinc binding and redox regulation are, at least in part, distinct determinants of the binding of p53 to DNA. Moreover, by substituting serine for each cysteine in murine p53, we have investigated the roles of individual cysteines in the regulation of p53 function. Substitution of serine for cysteine at position 40, 179, 274, 293, or 308 had little or no effect on p53 function. In contrast, replacement of cysteine at position 173, 235, or 239 markedly reduced in vitro DNA binding, completely blocked transcriptional activation, and led to a striking enhancement rather than a suppression of transformation by p53. These three cysteines have been implicated in zinc binding by X-ray diffraction studies (Y. Cho, S. Gorina, P.D. Jeffrey, and N.P. Pavletich, Science 265:346-355, 1994); our studies demonstrate the functional consequences of the inability of the central DNA-binding domain of p53 to studies demonstrate the functional consequences of the inability of the central DNA-binding domain of p53 to bind zinc. Lastly, substitutions for cysteines at position 121, 132, 138, or 272 partially blocked both transactivation and the suppression of transformation by p53. These four cysteines are located in the loop-sheet-helix region of the site-specific DNA-binding domain of p53. Like the cysteines in the zinc-binding region, therefore, these cysteines may cooperate to modulate the structure of the DNA-binding domain. Our findings argue that p53 is subject to more than one level of conformational modulation through oxidation-reduction of cysteines at or near the p53-DNA interface. PMID:7791795

  17. The emerging role of Nrf2 in mitochondrial function.

    PubMed

    Dinkova-Kostova, Albena T; Abramov, Andrey Y

    2015-11-01

    The transcription factor NF-E2 p45-related factor 2 (Nrf2; gene name NFE2L2) allows adaptation and survival under conditions of stress by regulating the gene expression of diverse networks of cytoprotective proteins, including antioxidant, anti-inflammatory, and detoxification enzymes as well as proteins that assist in the repair or removal of damaged macromolecules. Nrf2 has a crucial role in the maintenance of cellular redox homeostasis by regulating the biosynthesis, utilization, and regeneration of glutathione, thioredoxin, and NADPH and by controlling the production of reactive oxygen species by mitochondria and NADPH oxidase. Under homeostatic conditions, Nrf2 affects the mitochondrial membrane potential, fatty acid oxidation, availability of substrates (NADH and FADH2/succinate) for respiration, and ATP synthesis. Under conditions of stress or growth factor stimulation, activation of Nrf2 counteracts the increased reactive oxygen species production in mitochondria via transcriptional upregulation of uncoupling protein 3 and influences mitochondrial biogenesis by maintaining the levels of nuclear respiratory factor 1 and peroxisome proliferator-activated receptor γ coactivator 1α, as well as by promoting purine nucleotide biosynthesis. Pharmacological Nrf2 activators, such as the naturally occurring isothiocyanate sulforaphane, inhibit oxidant-mediated opening of the mitochondrial permeability transition pore and mitochondrial swelling. Curiously, a synthetic 1,4-diphenyl-1,2,3-triazole compound, originally designed as an Nrf2 activator, was found to promote mitophagy, thereby contributing to the overall mitochondrial homeostasis. Thus, Nrf2 is a prominent player in supporting the structural and functional integrity of the mitochondria, and this role is particularly crucial under conditions of stress. PMID:25975984

  18. The emerging role of Nrf2 in mitochondrial function

    PubMed Central

    Dinkova-Kostova, Albena T.; Abramov, Andrey Y.

    2015-01-01

    The transcription factor NF-E2 p45-related factor 2 (Nrf2; gene name NFE2L2) allows adaptation and survival under conditions of stress by regulating the gene expression of diverse networks of cytoprotective proteins, including antioxidant, anti-inflammatory, and detoxification enzymes as well as proteins that assist in the repair or removal of damaged macromolecules. Nrf2 has a crucial role in the maintenance of cellular redox homeostasis by regulating the biosynthesis, utilization, and regeneration of glutathione, thioredoxin, and NADPH and by controlling the production of reactive oxygen species by mitochondria and NADPH oxidase. Under homeostatic conditions, Nrf2 affects the mitochondrial membrane potential, fatty acid oxidation, availability of substrates (NADH and FADH2/succinate) for respiration, and ATP synthesis. Under conditions of stress or growth factor stimulation, activation of Nrf2 counteracts the increased reactive oxygen species production in mitochondria via transcriptional upregulation of uncoupling protein 3 and influences mitochondrial biogenesis by maintaining the levels of nuclear respiratory factor 1 and peroxisome proliferator-activated receptor γ coactivator 1α, as well as by promoting purine nucleotide biosynthesis. Pharmacological Nrf2 activators, such as the naturally occurring isothiocyanate sulforaphane, inhibit oxidant-mediated opening of the mitochondrial permeability transition pore and mitochondrial swelling. Curiously, a synthetic 1,4-diphenyl-1,2,3-triazole compound, originally designed as an Nrf2 activator, was found to promote mitophagy, thereby contributing to the overall mitochondrial homeostasis. Thus, Nrf2 is a prominent player in supporting the structural and functional integrity of the mitochondria, and this role is particularly crucial under conditions of stress. PMID:25975984

  19. Structure and function of the human patella: the role of cancellous bone.

    PubMed

    Townsend, P R; Miegel, R E; Rose, R M

    1976-07-01

    Total joint and other prosthesis often require the removal and replacement of considerable quantities of cancellous bone, and often are anchored in place by grouting into cancellous bone. Thus, a possible source of failure or loosening of many types of prostheses may be rooted in the lack of understanding of the structure, properties, and function of this material. In addition, as we have pointed out before, cancellous bone may play an important biomechanical role in the etiology of joint degeneration. With these considerations in mind, the architecture of the cancellous bone in the human patella was studied by serial sectioning and microradiography, using an improved technique developed in our laboratory. Volumes of cancellous bone with apparently different functional roles were identified. Stereological techniques were used to quantify the structural characteristics and geometrical relationships throughout the patella. These results led to a structural model for the cancellous bone of the patella, and a comprehensive picture of the internal architecture. The distribution of mechanical compliance and yield stress was also measured, as a function of location and orientation, by a specially constructed microcompression testing machine. The measurements reflected the distribution of trabecular architecture, and both the properties and architecture reflected the gross biomechanical function of the patella. Furthermore, a true structure-function relationship was derived. Patellar contact area studies were performed on fresh cadavers and mapped for various angles of flexion. The variation in contact areas and the spatial variations in stiffness are discussed relative to the biomechanics and clinical aspects of the patella. PMID:947922

  20. Transitioning between Work and Family Roles as a Function of Boundary Flexibility and Role Salience

    ERIC Educational Resources Information Center

    Winkel, Doan E.; Clayton, Russell W.

    2010-01-01

    This study investigates the manner in which people separate their work and family roles and how they manage the boundaries of these two important roles. Specifically, we focus on how role flexibility and salience influence transitions between roles. Results indicate that the ability and willingness to flex a role boundary and role salience are…

  1. Role of anaerobic fungi in wheat straw degradation and effects of plant feed additives on rumen fermentation parameters in vitro.

    PubMed

    Dagar, S S; Singh, N; Goel, N; Kumar, S; Puniya, A K

    2015-01-01

    In the present study, rumen microbial groups, i.e. total rumen microbes (TRM), total anaerobic fungi (TAF), avicel enriched bacteria (AEB) and neutral detergent fibre enriched bacteria (NEB) were evaluated for wheat straw (WS) degradability and different fermentation parameters in vitro. Highest WS degradation was shown for TRM, followed by TAF, NEB and least by AEB. Similar patterns were observed with total gas production and short chain fatty acid profiles. Overall, TAF emerged as the most potent individual microbial group. In order to enhance the fibrolytic and rumen fermentation potential of TAF, we evaluated 18 plant feed additives in vitro. Among these, six plant additives namely Albizia lebbeck, Alstonia scholaris, Bacopa monnieri, Lawsonia inermis, Psidium guajava and Terminalia arjuna considerably improved WS degradation by TAF. Further evaluation showed A. lebbeck as best feed additive. The study revealed that TAF plays a significant role in WS degradation and their fibrolytic activities can be improved by inclusion of A. lebbeck in fermentation medium. Further studies are warranted to elucidate its active constituents, effect on fungal population and in vivo potential in animal system. PMID:25391347

  2. Functional role of frontal alpha oscillations in creativity.

    PubMed

    Lustenberger, Caroline; Boyle, Michael R; Foulser, A Alban; Mellin, Juliann M; Fröhlich, Flavio

    2015-06-01

    Creativity, the ability to produce innovative ideas, is a key higher-order cognitive function that is poorly understood. At the level of macroscopic cortical network dynamics, recent electroencephalography (EEG) data suggests that cortical oscillations in the alpha frequency band (8-12 Hz) are correlated with creative thinking. However, whether alpha oscillations play a functional role in creativity has remained unknown. Here we show that creativity is increased by enhancing alpha power using 10 Hz transcranial alternating current stimulation (10 Hz-tACS) of the frontal cortex. In a study of 20 healthy participants with a randomized, balanced cross-over design, we found a significant improvement of 7.4% in the Creativity Index measured by the Torrance Test of Creative Thinking (TTCT), a comprehensive and most frequently used assay of creative potential and strengths. In a second similar study with 20 subjects, 40 Hz-tACS was used instead of 10 Hz-tACS to rule out a general "electrical stimulation" effect. No significant change in the Creativity Index was found for such frontal 40 Hz stimulation. Our results suggest that alpha activity in frontal brain areas is selectively involved in creativity; this enhancement represents the first demonstration of specific neuronal dynamics that drive creativity and can be modulated by non-invasive brain stimulation. Our findings agree with the model that alpha recruitment increases with internal processing demands and is involved in inhibitory top-down control, which is an important requirement for creative ideation. PMID:25913062

  3. Functional role of regulatory T cells in B cell lymphoma and related mechanisms.

    PubMed

    Wu, Wei; Wan, Jun; Xia, Ruixiang; Huang, Zhenqi; Ni, Jing; Yang, Mingzhen

    2015-01-01

    B cell lymphoma (BCL) has a higher degree of malignancy and complicated pathogenic mechanism. Regulatory T cells (Treg cells) are known to exert certain immune suppression functions, in addition to immune mediating effects. Recent studies have revealed the role of Treg cells in pathogenesis and progression of multiple malignant tumors. This study therefore investigated the functional role and related mechanism of Treg cells in BCL. A cohort of thirty patients who were diagnosed with BCL in our hospital between January 2013 and December 2014. Another thirty healthy individuals were recruited. Peripheral blood mononuclear cells (PBMCs) were separated and analyzed for the ratio of CD4+/CD25+ Treg cells. The mRNA expression levels of Foxp3, transforming growth factor (TGF)-β1 and interleukin (IL)-10 genes were quantified by real-time PCR, while their serum levels were determined by enzyme-linked immunosorbent assay (ELISA). Meanwhile all laboratory indexes for patients were monitored during the complete remission (CR) stage. BCL patients significantly elevated ratio of CD4+/CD25+ Treg cells, which were decreased at CR stage. mRNA levels of Foxp3, TGF-β1 and IL-10, in addition to protein levels of TGF-β1 and IL-10 were potentiated in lymphoma patients but decreased in CR patients (P<0.05 in all cases). CD4+/CD25+ Treg cells exert immune suppressing functions in BCL via regulating cytokines, thereby facilitating the pathogenesis and progression of lymphoma. PMID:26464657

  4. Additional F-Functions Useful for Preliminary Design of Shaped-Signature, Low-Boom, Supersonic-Cruise Aircraft

    NASA Technical Reports Server (NTRS)

    Mack, Robert J.

    1999-01-01

    Two additional low-boom F-functions have been described for use in designing low-boom, shaped-pressure-signature, supersonic-cruise aircraft. Based on the minimization studies of Seebass and George, the drag-nose shock strength trade-off modification of Darden, and the practical modification of Haglund, their use can aid in the design of conceptual low-boom aircraft, provide additional flexibility in the shaping of the low-boom aircraft nose section, and extend the applicability of shaped-pressure-signature methodology.

  5. Functional Roles of Protein Nitration in Acute and Chronic Liver Diseases

    PubMed Central

    Abdelmegeed, Mohamed A.; Song, Byoung-Joon

    2014-01-01

    Nitric oxide, when combined with superoxide, produces peroxynitrite, which is known to be an important mediator for a number of diseases including various liver diseases. Peroxynitrite can modify tyrosine residue(s) of many proteins resulting in protein nitration, which may alter structure and function of each target protein. Various proteomics and immunological methods including mass spectrometry combined with both high pressure liquid chromatography and 2D PAGE have been employed to identify and characterize nitrated proteins from pathological tissue samples to determine their roles. However, these methods contain a few technical problems such as low efficiencies with the detection of a limited number of nitrated proteins and labor intensiveness. Therefore, a systematic approach to efficiently identify nitrated proteins and characterize their functional roles is likely to shed new insights into understanding of the mechanisms of hepatic disease pathophysiology and subsequent development of new therapeutics. The aims of this review are to briefly describe the mechanisms of hepatic diseases. In addition, we specifically describe a systematic approach to efficiently identify nitrated proteins to study their causal roles or functional consequences in promoting acute and chronic liver diseases including alcoholic and nonalcoholic fatty liver diseases. We finally discuss translational research applications by analyzing nitrated proteins in evaluating the efficacies of potentially beneficial agents to prevent or treat various diseases in the liver and other tissues. PMID:24876909

  6. Discerning the role of mechanosensors in regulating proximal tubule function.

    PubMed

    Raghavan, Venkatesan; Weisz, Ora A

    2016-01-01

    All cells in the body experience external mechanical forces such as shear stress and stretch. These forces are sensed by specialized structures in the cell known as mechanosensors. Cells lining the proximal tubule (PT) of the kidney are continuously exposed to variations in flow rates of the glomerular ultrafiltrate, which manifest as changes in axial shear stress and radial stretch. Studies suggest that these cells respond acutely to variations in flow by modulating their ion transport and endocytic functions to maintain glomerulotubular balance. Conceptually, changes in the axial shear stress in the PT could be sensed by three known structures, namely, the microvilli, the glycocalyx, and primary cilia. The orthogonal component of the force produced by flow exhibits as radial stretch and can cause expansion of the tubule. Forces of stretch are transduced by integrins, by stretch-activated channels, and by cell-cell contacts. This review summarizes our current understanding of flow sensing in PT epithelia, discusses challenges in dissecting the role of individual flow sensors in the mechanosensitive responses, and identifies potential areas of opportunity for new study. PMID:26662200

  7. Functional role of KLF10 in multiple disease processes

    PubMed Central

    Subramaniam, Malayannan; Hawse, John R.; Rajamannan, Nalini M.; Ingle, James N.; Spelsberg, Thomas C.

    2011-01-01

    Since the discovery by this laboratory of the zinc finger transcription factor, KLF10, a member of the Krüppel-like family of transcription factors, there have been multiple publications regarding its functions and its immediate family members, in numerous cell types. KLF10 has been shown to be rapidly induced by TGFβ1, 2, 3, E2, epidermal growth factor, and bone morphogenetic protein-2. TGFβ inducible early gene-1 activates the TGFβ-Smad signaling pathway via repression of Smad 7 expression and activation of Smad 2 expression and activity. Overall, KLF10 has been implicated in cell differentiation, as a target gene for a variety of signaling pathways, and in serving as a potential marker for human diseases such as breast cancer, cardiac hypertrophy, and osteoporosis. Like other KLF members, KLF10 is expressed in specific cell types in numerous tissues and is known to be involved in repressing cell proliferation and inflammation as well as inducing apoptosis similar to that of TGFβ KLF10 binds to Sp-1-GC rich DNA sequences and can activate or repress the transcription of a number of genes. Overall, KLF10 has been shown to play a major role in the TGFβ inhibition of cell proliferation and inflammation and induction of apoptosis, and its overexpression in human osteoblasts and pancreatic carcinoma cells mimics the actions of TGFβ. PMID:20087894

  8. Roles of subunit phosphorylation in regulating glutamate receptor function

    PubMed Central

    Wang, John Q.; Guo, Ming-Lei; Jin, Dao-Zhong; Xue, Bing; Fibuch, Eugene E.; Mao, Li-Min

    2014-01-01

    Protein phosphorylation is an important mechanism for regulating ionotropic glutamate receptors (iGluRs). Early studies have established that major iGluR subtypes, including α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors and N-methyl-D-aspartate (NMDA) receptors, are subject to phosphorylation. Multiple serine, threonine, and tyrosine residues predominantly within the C-terminal regions of AMPA receptor and NMDA receptor subunits have been identified as sensitive phosphorylation sites. These distinct sites undergo either constitutive phosphorylation or activity-dependent phosphorylation induced by changing cellular and synaptic inputs as reversible events. An increasing number of synapse-enriched protein kinases have been found to phosphorylate iGluR. The common kinases include protein kinase A, protein kinase C, Ca2+/calmodulin-dependent protein kinase II, Src/Fyn non-receptor tyrosine kinases, and cyclin dependent kinase-5. Regulated phosphorylation plays a well-documented role in modulating the biochemical, biophysical, and functional properties of the receptor. In the future, identifying the precise mechanisms how phosphorylation regulates iGluR activities and finding the link between iGluR phosphorylation and the pathogenesis of various brain diseases, including psychiatric and neurodegenerative diseases, chronic pain, stroke, Alzheimer’s disease and substance addiction, will be hot topics and could contribute to the development of novel pharmacotherapies, by targeting the defined phosphorylation process, for suppressing iGluR-related disorders. PMID:24291102

  9. Functional role of lipid rafts in CD20 activity?

    PubMed

    Janas, Eva; Priest, Richard; Malhotra, Rajneesh

    2005-01-01

    CD20 is a B-lymphocyte-specific integral membrane protein, implicated in the regulation of transmembrane calcium conductance, cell-cycle progression and B-lymphocyte proliferation. CD20 is proposed to function as a SOCC (store-operated calcium channel). SOCCs are activated by receptor-stimulated calcium depletion of intracellular stores. Sustained calcium conductivity across the plasma membrane mediated by SOCC activity is required for long-term calcium-dependent processes, such as transcriptional control and gene expression. Cross-linking of CD20 by antibodies (e.g. Rituxan) has been reported to induce a rapid redistribution of CD20 into specialized microdomains at the plasma membrane, known as lipid rafts. Recruitment of CD20 into lipid rafts and its homo-oligomerization are suggested to be crucial for CD20 activity and regulation. This review outlines recent biochemical studies characterizing the role of CD20 in calcium signalling in B-lymphocytes and evaluates an engagement of lipid rafts in the regulation of CD20-mediated calcium conductivity. PMID:15649140

  10. Fabrication of Fe-FeAl Functionally Graded Material Using the Wire-Arc Additive Manufacturing Process

    NASA Astrophysics Data System (ADS)

    Shen, Chen; Pan, Zengxi; Cuiuri, Dominic; Roberts, Jon; Li, Huijun

    2016-02-01

    A functionally gradient iron-aluminum wall structure with aluminum composition gradient from 0 at. pct to over 50 at. pct is fabricated using a wire-arc additive manufacturing (WAAM) system. The as-fabricated alloy is investigated using optical microstructure analysis, hardness testing, tensile testing, X-ray diffraction phase characterization, and electron-dispersive spectrometry. The comprehensive analysis of the experimental samples has shown that the WAAM system can be used for manufacturing iron aluminide functionally graded material with full density, desired composition, and reasonable mechanical properties.

  11. An analytical approach to the problem of inverse optimization with additive objective functions: an application to human prehension

    PubMed Central

    Pesin, Yakov B.; Niu, Xun; Latash, Mark L.

    2010-01-01

    We consider the problem of what is being optimized in human actions with respect to various aspects of human movements and different motor tasks. From the mathematical point of view this problem consists of finding an unknown objective function given the values at which it reaches its minimum. This problem is called the inverse optimization problem. Until now the main approach to this problems has been the cut-and-try method, which consists of introducing an objective function and checking how it reflects the experimental data. Using this approach, different objective functions have been proposed for the same motor action. In the current paper we focus on inverse optimization problems with additive objective functions and linear constraints. Such problems are typical in human movement science. The problem of muscle (or finger) force sharing is an example. For such problems we obtain sufficient conditions for uniqueness and propose a method for determining the objective functions. To illustrate our method we analyze the problem of force sharing among the fingers in a grasping task. We estimate the objective function from the experimental data and show that it can predict the force-sharing pattern for a vast range of external forces and torques applied to the grasped object. The resulting objective function is quadratic with essentially non-zero linear terms. PMID:19902213

  12. Hyperglycemia decreases mitochondrial function: The regulatory role of mitochondrial biogenesis

    SciTech Connect

    Palmeira, Carlos M. Rolo, Anabela P.; Berthiaume, Jessica; Bjork, James A.; Wallace, Kendall B.

    2007-12-01

    Increased generation of reactive oxygen species (ROS) is implicated in 'glucose toxicity' in diabetes. However, little is known about the action of glucose on the expression of transcription factors in hepatocytes, especially those involved in mitochondrial DNA (mtDNA) replication and transcription. Since mitochondrial functional capacity is dynamically regulated, we hypothesized that stressful conditions of hyperglycemia induce adaptations in the transcriptional control of cellular energy metabolism, including inhibition of mitochondrial biogenesis and oxidative metabolism. Cell viability, mitochondrial respiration, ROS generation and oxidized proteins were determined in HepG2 cells cultured in the presence of either 5.5 mM (control) or 30 mM glucose (high glucose) for 48 h, 96 h and 7 days. Additionally, mtDNA abundance, plasminogen activator inhibitor-1 (PAI-1), mitochondrial transcription factor A (TFAM) and nuclear respiratory factor-1 (NRF-1) transcripts were evaluated by real time PCR. High glucose induced a progressive increase in ROS generation and accumulation of oxidized proteins, with no changes in cell viability. Increased expression of PAI-1 was observed as early as 96 h of exposure to high glucose. After 7 days in hyperglycemia, HepG2 cells exhibited inhibited uncoupled respiration and decreased MitoTracker Red fluorescence associated with a 25% decrease in mtDNA and 16% decrease in TFAM transcripts. These results indicate that glucose may regulate mtDNA copy number by modulating the transcriptional activity of TFAM in response to hyperglycemia-induced ROS production. The decrease of mtDNA content and inhibition of mitochondrial function may be pathogenic hallmarks in the altered metabolic status associated with diabetes.

  13. Cobalt(III)-Catalyzed Synthesis of Indazoles and Furans by C–H Bond Functionalization/Addition/Cyclization Cascades

    PubMed Central

    2015-01-01

    The development of operationally straightforward and cost-effective routes for the assembly of heterocycles from simple inputs is important for many scientific endeavors, including pharmaceutical, agrochemical, and materials research. In this article we describe the development of a new air-stable cationic Co(III) catalyst for convergent, one-step benchtop syntheses of N-aryl-2H-indazoles and furans by C–H bond additions to aldehydes followed by in situ cyclization and aromatization. Only a substoichiometric amount of AcOH is required as an additive that is both low-cost and convenient to handle. The syntheses of these heterocycles are the first examples of Co(III)-catalyzed additions to aldehydes, and reactions are demonstrated for a variety of aromatic, heteroaromatic, and aliphatic derivatives. The syntheses of both N-aryl-2H-indazoles and furans have been performed on 20 mmol scales and should be readily applicable to larger scales. The reported heterocycle syntheses also demonstrate the use of directing groups that have not previously been applied to Co(III)-catalyzed C–H bond functionalizations. Additionally, the synthesis of furans demonstrates the first example of Co(III)-catalyzed functionalization of alkenyl C–H bonds. PMID:25494296

  14. Separable roles of UFO during floral development revealed by conditional restoration of gene function.

    PubMed

    Laufs, Patrick; Coen, Enrico; Kronenberger, Jocelyne; Traas, Jan; Doonan, John

    2003-02-01

    The UNUSUAL FLORAL ORGANS (UFO) gene is required for several aspects of floral development in Arabidopsis including specification of organ identity in the second and third whorls and the proper pattern of primordium initiation in the inner three whorls. UFO is expressed in a dynamic pattern during the early phases of flower development. Here we dissect the role of UFO by ubiquitously expressing it in ufo loss-of-function flowers at different developmental stages and for various durations using an ethanol-inducible expression system. The previously known functions of UFO could be separated and related to its expression at specific stages of development. We show that a 24- to 48-hour period of UFO expression from floral stage 2, before any floral organs are visible, is sufficient to restore normal petal and stamen development. The earliest requirement for UFO is during stage 2, when the endogenous UFO gene is transiently expressed in the centre of the wild-type flower and is required to specify the initiation patterns of petal, stamen and carpel primordia. Petal and stamen identity is determined during stages 2 or 3, when UFO is normally expressed in the presumptive second and third whorl. Although endogenous UFO expression is absent from the stamen whorl from stage 4 onwards, stamen identity can be restored by UFO activation up to stage 6. We also observed floral phenotypes not observed in loss-of-function or constitutive gain-of-function backgrounds, revealing additional roles of UFO in outgrowth of petal primordia. PMID:12506008

  15. Systematic Dissection of Coding Exons at Single Nucleotide Resolution Supports an Additional Role in Cell-Specific Transcriptional Regulation

    PubMed Central

    Kim, Mee J.; Findlay, Gregory M.; Martin, Beth; Zhao, Jingjing; Bell, Robert J. A.; Smith, Robin P.; Ku, Angel A.; Shendure, Jay; Ahituv, Nadav

    2014-01-01

    In addition to their protein coding function, exons can also serve as transcriptional enhancers. Mutations in these exonic-enhancers (eExons) could alter both protein function and transcription. However, the functional consequence of eExon mutations is not well known. Here, using massively parallel reporter assays, we dissect the enhancer activity of three liver eExons (SORL1 exon 17, TRAF3IP2 exon 2, PPARG exon 6) at single nucleotide resolution in the mouse liver. We find that both synonymous and non-synonymous mutations have similar effects on enhancer activity and many of the deleterious mutation clusters overlap known liver-associated transcription factor binding sites. Carrying a similar massively parallel reporter assay in HeLa cells with these three eExons found differences in their mutation profiles compared to the liver, suggesting that enhancers could have distinct operating profiles in different tissues. Our results demonstrate that eExon mutations could lead to multiple phenotypes by disrupting both the protein sequence and enhancer activity and that enhancers can have distinct mutation profiles in different cell types. PMID:25340400

  16. Role of extracellular polymeric substances in enhancement of phosphorus release from waste activated sludge by rhamnolipid addition.

    PubMed

    He, Zhang-Wei; Liu, Wen-Zong; Wang, Ling; Yang, Chun-Xue; Guo, Ze-Chong; Zhou, Ai-Juan; Liu, Jian-Yong; Wang, Ai-Jie

    2016-02-01

    This study investigated the role of extracellular polymeric substances (EPSs) in enhanced performance of phosphorus (P) release from waste activated sludge (WAS) by adding rhamnolipid (RL). Results showed that compared to WAS without pretreatment, the released PO4(3-)-P increased with RL addition from 0 to 0.2 g/gTSS (total suspended solid), and increased by 208% under the optimal condition (0.1 g RL/g TSS and 72-h fermentation time). The cumulative PO4(3-)-P was better fitted with pseudo-first-order kinetic model. Moreover, the contents of metal ions increased in liquid but decreased in EPSs linearly with RL addition increasing, and WAS solubilizations were positively correlated with the released metal ions. The enhanced total dissolved P mainly came from cells and others (69.39%, 2.27-fold higher than that from EPSs), and PO4(3-)-P was the main species in both liquid and loosely bound EPSs, but organic P should be non-negligible in tightly bound EPSs. PMID:26700759

  17. CoQ₁₀ Function and Role in Heart Failure and Ischemic Heart Disease.

    PubMed

    Ayer, Anita; Macdonald, Peter; Stocker, Roland

    2015-01-01

    Coenzyme Q (CoQ) is an essential lipid of cells present in all cellular compartments. The functions of CoQ in mitochondrial respiration and as an antioxidant are established, although the lipid likely has additional, presently unknown, roles. While the therapeutic utility of CoQ10 supplements is recognized in the rare cases of primary CoQ10 deficiencies, a potential role for CoQ10 supplements in cardiovascular disease, particularly heart failure, has also been studied for over 40 years. This review summarizes our current knowledge in these areas derived from animal studies and human trials. Current evidence for a benefit of CoQ10 supplements in diseases other than primary CoQ10 deficiencies is insufficient. PMID:25974695

  18. On the performance of low pressure die-cast Al-Cu based automotive alloys: Role of additives

    NASA Astrophysics Data System (ADS)

    Zaki, Gergis Adel

    The present study focuses on the effect of alloying elements, namely, strontium (Sr), titanium (Ti), zirconium (Zr), scandium (Sc) and silver(Ag) individually or in combination, on the performance of a newly developed Al-2%Cu based alloy. A total of thirteen alloy compositions were used in the study. Tensile test bar castings were prepared employing the low pressure die casting (LPDC) technique. The test bars were solution heat treated at 495°C for 8 hours, followed by quenching in warm water, and then subjected to different isochronal aging treatments using an aging time of 5 hours and aging temperatures of 155°C, 180°C, 200°C, 240°C and 300°C. Tensile testing of as-cast and heat-treated test bars was carried out at room temperature using a strain rate of 4 x 10-4s-1. Five test bars were used per alloy composition/condition. Hardness measurements were also carried out on these alloys using a Brinell hardness tester. The microstructures of selected samples were examined using optical microscopy and electron probe microanalysis (EPMA). The results showed that adding Ti in the amount of 0.15 wt% in the form of Al-5%Ti-1%B master alloy is sufficient to refine the grains in the cast structure in the presence of 200 ppm Sr (0.02 wt%). Addition of Zr and Sc did not contribute further to the grain refining effect. The main role of addition of these two elements appeared in the formation of complex compounds with Al and Ti. Their presence resulted in extending the aging temperature range before the onset of softening. Mathematical analysis of the hardness and tensile data was carried out using the Minitab statistical software program. It was determined that the alloy containing (0.5wt% Zr + 0.15wt% Ti) is the most effective in maximizing the alloy tensile strength over the range of aging temperatures, from 155°C to 300°C. Addition of Ag is beneficial at high aging temperatures, in the range of 240°C-300°C. However, it is less effective compared to the (Zr + Ti

  19. [Novel role of growth factors in ovary function].

    PubMed

    Amsterdam, Abraham

    2010-12-01

    The development of the DNA microarray technique facilitated systematic studies of the modulation of gene function. Considerable attention has been focused on members of the growth factor family to elucidate the main regulators of oocyte maturation and ovarian follicle rupture. Among these growth factors, it was found, both in rodents and in humans, that amphiregulin (Ar) and epiregulin (Ep) of the epidermal growth factor (EGF) family were dramatically up-regulated by gonadotrophins in the intact ovary and in primary granulosa cells, respectively. Their role in cumulus expansion and oocyte maturation was established in rodents, and their synthesis under LH stimulation in granulosa cells was demonstrated in humans. To be activated, Ar and Ep must be cleaved by a disintegrin and metalloproteinases (ADAMs) family. However, the precise processing of Ar and Ep by the cumulus cells is still obscure. Future investigations using DNA microarray technique may reveal the repertoire of genes activated in Ar- and Ep-stimulated cumulus cells and may help elucidate the molecular basis of ovulation. EFG-like factors are also involved in triggering ovarian cancer The author hypothesized that the normal ovary maintains cyclicity in the formation of these growth factors preventing the ovary from developing ovarian cancer In ovarian cancer these growth factors are continuously formed in an autocrine manner, leading to transformation and subsequently to ovarian cancer. These growth factors are essential for both normal and neoplastic transformation of the ovary. Taking into consideration these growth factors in the treatment of ovarian malfunction may be one way of curing ovarian cancer. PMID:21916103

  20. A novel role for TRPM8 in visceral afferent function.

    PubMed

    Harrington, Andrea M; Hughes, Patrick A; Martin, Christopher M; Yang, Jing; Castro, Joel; Isaacs, Nicole J; Blackshaw, L Ashley; Brierley, Stuart M

    2011-07-01

    Transient receptor potential ion channel melastatin subtype 8 (TRPM8) is activated by cold temperatures and cooling agents, such as menthol and icilin. Compounds containing peppermint are reported to reduce symptoms of bowel hypersensitivity; however, the underlying mechanisms of action are unclear. Here we determined the role of TRPM8 in colonic sensory pathways. Laser capture microdissection, quantitative reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescence, and retrograde tracing were used to localise TRPM8 to colonic primary afferent neurons. In vitro extracellular single-fibre afferent recordings were used to determine the effect of TRPM8 channel activation on the chemosensory and mechanosensory function of colonic high-threshold afferent fibres. TRPM8 mRNA was present in colonic DRG neurons, whereas TRPM8 protein was present on nerve fibres throughout the wall of the colon. A subpopulation (24%, n=58) of splanchnic serosal and mesenteric afferents tested responded directly to icilin (5 μmol/L). Subsequently, icilin significantly desensitised afferents to mechanical stimulation (P<.0001; n=37). Of the splanchnic afferents responding to icilin, 21 (33%) also responded directly to the TRPV1 agonist capsaicin (3 μmol/L), and icilin reduced the direct chemosensory response to capsaicin. Icilin also prevented mechanosensory desensitization and sensitization induced by capsaicin and the TRPA1 agonist AITC (40 μmol/L), respectively. TRPM8 is present on a select population of colonic high threshold sensory neurons, which may also co-express TRPV1. TRPM8 couples to TRPV1 and TRPA1 to inhibit their downstream chemosensory and mechanosensory actions. PMID:21489690

  1. Characteristics and Functional Roles of Opioids Originally Present in Vivo.

    PubMed

    Ozaki, Masanobu

    2016-01-01

    The characteristics and functional roles of opioids originally present in vivo (endogenous opioids) in guinea-pig ileum were investigated. The release of endogenous opioids was determined by the inhibitory twitch response evoked by 0.1 Hz stimulation after 10 Hz stimulation (post-tetanic twitch inhibition). The effects of peptidase inhibitors increased the post-tetanic twitch inhibition, prevented by β-funaltrexamine and nor-binaltorphimine, which are selective μ- and κ-opioid receptor subtype antagonists, respectively. Dopamine receptor antagonists (haloperidol, sultopride and domperidone) increased the post-tetanic twitch inhibition. These results suggest that dopamine receptors are involved in modulation of the ileal opioid system, so as to diminish endogenous opioid release by tetanic stimulation, and dopamine antagonists increase the opioid action, that might depend more on the increased release of endogenous opioids. The post-tetanic twitch inhibition was inhibited by adrenalectomy, and showed the supersensitivity of the opioid receptors, resulting from a decrease of endogenous opioids by adrenalectomy. These findings suggest that the increase in morphine-analgesia by adrenalectomy was due to this process. In the presence of naloxone, an opioid antagonist, an increase in basal tension after tetanic stimulation (10 Hz stimulation) (post-tetanic contraction) was observed, and was blocked by spantide, a substance P antagonist, and indomethacin, a prostaglandins-biosynthesis inhibitor. This contraction increased with morphine or peptidase inhibitor exposure, depending on the length of time the ileum was exposed to the morphine or peptidase inhibitor. Post-tetanic contraction might be a useful indicator of the formation of physical dependence to morphine or endogenous opioids in the ileum. PMID:27040344

  2. Genomic-scale comparison of sequence- and structure-based methods of function prediction: Does structure provide additional insight?

    PubMed Central

    Fetrow, Jacquelyn S.; Siew, Naomi; Di Gennaro, Jeannine A.; Martinez-Yamout, Maria; Dyson, H. Jane; Skolnick, Jeffrey

    2001-01-01

    A function annotation method using the sequence-to-structure-to-function paradigm is applied to the identification of all disulfide oxidoreductases in the Saccharomyces cerevisiae genome. The method identifies 27 sequences as potential disulfide oxidoreductases. All previously known thioredoxins, glutaredoxins, and disulfide isomerases are correctly identified. Three of the 27 predictions are probable false-positives. Three novel predictions, which subsequently have been experimentally validated, are presented. Two additional novel predictions suggest a disulfide oxidoreductase regulatory mechanism for two subunits (OST3 and OST6) of the yeast oligosaccharyltransferase complex. Based on homology, this prediction can be extended to a potential tumor suppressor gene, N33, in humans, whose biochemical function was not previously known. Attempts to obtain a folded, active N33 construct to test the prediction were unsuccessful. The results show that structure prediction coupled with biochemically relevant structural motifs is a powerful method for the function annotation of genome sequences and can provide more detailed, robust predictions than function prediction methods that rely on sequence comparison alone. PMID:11316881

  3. The Unique and Additive Associations of Family Functioning and Parenting Practices with Disordered Eating Behaviors in Diverse Adolescents

    PubMed Central

    Berge, Jerica M.; Wall, Melanie; Larson, Nicole; Eisenberg, Marla E.; Loth, Katie A.; Neumark-Sztainer, Dianne

    2012-01-01

    Objective To examine the unique and additive associations of family functioning and parenting practices with adolescent disordered eating behaviors (i.e., dieting, unhealthy weight control behaviors, binge eating). Methods Data from EAT (Eating and Activity in Teens) 2010, a population-based study assessing eating and activity among racially/ethnically and socio-economically diverse adolescents (n = 2,793; mean age = 14.4, SD = 2.0; age range = 11–19) was used. Logistic regression models were used to examine associations between adolescent dieting and disordered eating behaviors and family functioning and parenting variables, including interactions. All analyses controlled for demographics and body mass index. Results Higher family functioning, parent connection, and parental knowledge about child’s whereabouts (e.g. who child is with, what they are doing, where they are at) were significantly associated with lower odds of engaging in dieting and disordered eating behaviors in adolescents, while parent psychological control was associated with greater odds of engaging in dieting and disordered eating behaviors. Although the majority of interactions were non-significant, parental psychological control moderated the protective relationship between family functioning and disordered eating behaviors in adolescent girls. Conclusions Clinicians and health care providers may want to discuss the importance of balancing specific parenting behaviors, such as increasing parent knowledge about child whereabouts while decreasing psychological control in order to enhance the protective relationship between family functioning and disordered eating behaviors in adolescents. PMID:23196919

  4. Non-Structural Proteins of Arthropod-Borne Bunyaviruses: Roles and Functions

    PubMed Central

    Eifan, Saleh; Schnettler, Esther; Dietrich, Isabelle; Kohl, Alain; Blomström, Anne-Lie

    2013-01-01

    Viruses within the Bunyaviridae family are tri-segmented, negative-stranded RNA viruses. The family includes several emerging and re-emerging viruses of humans, animals and plants, such as Rift Valley fever virus, Crimean-Congo hemorrhagic fever virus, La Crosse virus, Schmallenberg virus and tomato spotted wilt virus. Many bunyaviruses are arthropod-borne, so-called arboviruses. Depending on the genus, bunyaviruses encode, in addition to the RNA-dependent RNA polymerase and the different structural proteins, one or several non-structural proteins. These non-structural proteins are not always essential for virus growth and replication but can play an important role in viral pathogenesis through their interaction with the host innate immune system. In this review, we will summarize current knowledge and understanding of insect-borne bunyavirus non-structural protein function(s) in vertebrate, plant and arthropod. PMID:24100888

  5. Roles and functions of HIV-1 Tat protein in the CNS: an overview

    PubMed Central

    2013-01-01

    Nearly 50% of HIV-infected individuals suffer from some form of HIV-associated neurocognitive disorders (HAND). HIV-1 Tat (a key HIV transactivator of transcription) protein is one of the first HIV proteins to be expressed after infection occurs and is absolutely required for the initiation of the HIV genome transcription. In addition to its canonical functions, various studies have shown the deleterious role of HIV-1 Tat in the development and progression of HAND. Within the CNS, only specific cell types can support productive viral replication (astrocytes and microglia), however Tat protein can be released form infected cells to affects HIV non-permissive cells such as neurons. Therefore, in this review, we will summarize the functions of HIV-1 Tat proteins in neural cells and its ability to promote HAND. PMID:24359561

  6. Translating the basic knowledge of mitochondrial functions to metabolic therapy: role of L-carnitine.

    PubMed

    Marcovina, Santica M; Sirtori, Cesare; Peracino, Andrea; Gheorghiade, Mihai; Borum, Peggy; Remuzzi, Giuseppe; Ardehali, Hossein

    2013-02-01

    Mitochondria play important roles in human physiological processes, and therefore, their dysfunction can lead to a constellation of metabolic and nonmetabolic abnormalities such as a defect in mitochondrial gene expression, imbalance in fuel and energy homeostasis, impairment in oxidative phosphorylation, enhancement of insulin resistance, and abnormalities in fatty acid metabolism. As a consequence, mitochondrial dysfunction contributes to the pathophysiology of insulin resistance, obesity, diabetes, vascular disease, and chronic heart failure. The increased knowledge on mitochondria and their role in cellular metabolism is providing new evidence that these disorders may benefit from mitochondrial-targeted therapies. We review the current knowledge of the contribution of mitochondrial dysfunction to chronic diseases, the outcomes of experimental studies on mitochondrial-targeted therapies, and explore the potential of metabolic modulators in the treatment of selected chronic conditions. As an example of such modulators, we evaluate the efficacy of the administration of L-carnitine and its analogues acetyl and propionyl L-carnitine in several chronic diseases. L-carnitine is intrinsically involved in mitochondrial metabolism and function as it plays a key role in fatty acid oxidation and energy metabolism. In addition to the transportation of free fatty acids across the inner mitochondrial membrane, L-carnitine modulates their oxidation rate and is involved in the regulation of vital cellular functions such as apoptosis. Thus, L-carnitine and its derivatives show promise in the treatment of chronic conditions and diseases associated with mitochondrial dysfunction but further translational studies are needed to fully explore their potential. PMID:23138103

  7. The role(s) of Src kinase and Cbl proteins in the regulation of osteoclast differentiation and function.

    PubMed

    Horne, William C; Sanjay, Archana; Bruzzaniti, Angela; Baron, Roland

    2005-12-01

    The osteoclast resorbs mineralized bone during bone development, homeostasis, and repair. The deletion of the gene encoding the nonreceptor tyrosine kinase c-Src produces an osteopetrotic skeletal phenotype that is the consequence of the inability of the mature osteoclast to efficiently resorb bone. Src-/- osteoclasts exhibit reduced motility and abnormal organization of the apical secretory domain (the ruffled border) and attachment-related cytoskeletal elements that are necessary for bone resorption. A key function of Src in osteoclasts is to promote the rapid assembly and disassembly of the podosomes, the specialized integrin-based attachment structures of osteoclasts and other highly motile cells. Once recruited to the activated integrins, especially alphavbeta3), by the adhesion tyrosine kinase Pyk2, Src binds and phosphorylates Cbl and Cbl-b, homologous multisite adapter proteins with ubiquitin ligase activity. The Cbl proteins in turn recruit and activate additional signaling effectors, including phosphatidylinositol 3-kinase and dynamin, which play key roles in the development of cell polarity and the regulation of cell attachment and motility. In addition, Src and the Cbl proteins contribute to signaling cascades that are activated by several important receptors, including receptor activator of nuclear factor kappaB and the macrophage colony-stimulating factor receptor, and also downregulate the signaling from many of these receptors. PMID:16313344

  8. Performance of Forage Mixtures Constructed to Fulfill Multiple Functional Roles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ecological theory predicts that complex pasture communities that include numerous plant functional types should be more productive, stable, and better at excluding weeds than simple communities with few functional types. In a series of greenhouse and field studies, six unique functional attributes c...

  9. The role of psychosocial factors in functional gut disease.

    PubMed

    Kamm, M A

    1998-01-01

    The link between psychological factors and functional gut disorders is indisputable. This review considers some of the mechanisms by which psychological state affect gut function, how these psychological factors and their effects on the gut might be measured, and how psychological treatments might benefit patients with functional disorders. PMID:10027671

  10. Dosage and duration effects of nitrogen additions on ectomycorrhizal sporocarp production and functioning: an example from two N-limited boreal forests

    PubMed Central

    Hasselquist, Niles J; Högberg, Peter

    2014-01-01

    Although it is well known that nitrogen (N) additions strongly affect ectomycorrhizal (EM) fungal community composition, less is known about how different N application rates and duration of N additions affect the functional role EM fungi play in the forest N cycle.We measured EM sporocarp abundance and species richness as well as determined the δ15N in EM sporocarps and tree foliage in two Pinus sylvestris forests characterized by short- and long-term N addition histories and multiple N addition treatments. After 20 and 39 years of N additions, two of the long-term N addition treatments were terminated, thereby providing a unique opportunity to examine the temporal recovery of EM sporocarps after cessation of high N loading.In general, increasing N availability significantly reduced EM sporocarp production, species richness, and the amount of N retained in EM sporocarps. However, these general responses were strongly dependent on the application rate and duration of N additions. The annual addition of 20 kg·N·ha−1 for the past 6 years resulted in a slight increase in the production and retention of N in EM sporocarps, whereas the addition of 100 kg·N·ha−1·yr−1 during the same period nearly eliminated EM sporocarps. In contrast, long-term additions of N at rates of ca. 35 or 70 kg·N·ha−1·yr−1 for the past 40 years did not eliminate tree carbon allocation to EM sporocarps, although there was a decrease in the abundance and a shift in the dominant EM sporocarp taxa. Despite no immediate recovery, EM sporocarp abundance and species richness approached those of the control 20 years after terminating N additions in the most heavily fertilized treatment, suggesting a recovery of carbon allocation to EM sporocarps after cessation of high N loading.Our results provide evidence for a tight coupling between tree carbon allocation to and N retention in EM sporocarps and moreover highlight the potential use of δ15N in EM sporocarps as a relative

  11. Correlates of Substance Use Disorder among Psychiatric Outpatients: Focus on Cognition, Social Role Functioning and Psychiatric Status

    PubMed Central

    Carey, Kate B.; Carey, Michael P.; Simons, Jeffrey S.

    2008-01-01

    This study compared psychiatric outpatients who were never, former, and current substance abusers on psychiatric, social, and cognitive functioning. Fifty-six outpatients with schizophrenia-spectrum and bipolar disorders volunteered to complete diagnostic and social role function interviews, self-report inventories, and neuropsychological tests. Multinomial logit regression analyses indicated that current and former abusers reported greater subjective feelings of distress than those who never abused. Contrary to expectations, however, both groups of substance abusers performed better on non-verbal cognitive tests compared to those who never abused. Differences in social functioning were also observed: former abusers demonstrated better instrumental role functioning than those who never abused. This pattern of findings challenges assumptions about additive effects of comorbid disorders on cognitive and social functioning. PMID:12819549

  12. Case managers' roles and functions: Commission for Case Manager Certification's 2004 Research, Part I.

    PubMed

    Tahan, Hussein A; Huber, Diane L; Downey, William T

    2006-01-01

    The Commission for Case Manager Certification (CCMC) conducted its third case managers' role and functions study in 2004. The purpose of this research was to validate the currency and relevancy of the certified case manager examination. The results of this study are shared in 2 parts of an article. Part I discusses the process the CCMC used for the development of the Case Manager's Role and Functions Survey Instrument (CMRFSI). The research leads to the identification of 6 new essential functions and 6 new knowledge areas, which describe case management practice. These findings were based on the survey of a large national sample of practicing case managers. Part II continues the analysis of the survey results and focuses on identifying the empirical activity and knowledge domains of case management practice, using factor analysis. It also discusses the similarities and differences found among various subgroups of case managers who were compared on the basis of certain demographic variables. In addition, it summarizes future changes in the field of case management as perceived by those who participated in the study. PMID:16444117

  13. Case managers' roles and functions: Commission for Case Manager Certification's 2004 research, part II.

    PubMed

    Tahan, Hussein A; Downey, William T; Huber, Diane L

    2006-01-01

    The Commission for Case Manager Certification (CCMC) conducted its third case managers' role and functions study in 2004 for the purpose of validating the currency and relevancy of the certified case manager examination. The results of this study are shared in an article of 2 parts. Part I, which was published in the previous issue of this journal, discussed the process the CCMC used for the development of the Case Managers' Role and Functions Survey Instrument and the identification of new 6 essential functions and 6 knowledge areas that describe case management practice. These findings were based on the survey of a large national sample of practicing case managers. Part II continues the analysis of the results and focuses on identifying the empirical (statistically derived) activity and knowledge domains of case management practice, using exploratory factor analysis. It discusses the similarities and differences found among various subgroups of case managers who were compared on the basis of certain demographic variables. In addition, Part II summarizes future changes in the field of case management as perceived by those who participated in the study. PMID:16582699

  14. [A role of WNT in kidney development and function].

    PubMed

    Mesar, Ines; Kes, Petar; Jukić, Nikolina Basić

    2012-10-01

    WNT 4 is a secreted glycoprotein that is critical for nephrogenesis during mesenchymal to epithelial transformation. Lately there are some experimental modles witch confirm a role of Wnt 4 during regeneration process in acute renal failure. On the other hand there are some evidence that Wnt 4 plays important role in renal fibrosis during experimental renal injury in rats that provide tubuloinerstitial fibrosis. When will Wnt 4 have a protective role or when will induce fibrosis still is not known and therefore futher studies will be necessary to gain a more precise understanding. PMID:23513417

  15. Effect of additive particles on mechanical, thermal, and cell functioning properties of poly(methyl methacrylate) cement

    PubMed Central

    Khandaker, Morshed; Vaughan, Melville B; Morris, Tracy L; White, Jeremiah J; Meng, Zhaotong

    2014-01-01

    The most common bone cement material used clinically today for orthopedic surgery is poly(methyl methacrylate) (PMMA). Conventional PMMA bone cement has several mechanical, thermal, and biological disadvantages. To overcome these problems, researchers have investigated combinations of PMMA bone cement and several bioactive particles (micrometers to nanometers in size), such as magnesium oxide, hydroxyapatite, chitosan, barium sulfate, and silica. A study comparing the effect of these individual additives on the mechanical, thermal, and cell functional properties of PMMA would be important to enable selection of suitable additives and design improved PMMA cement for orthopedic applications. Therefore, the goal of this study was to determine the effect of inclusion of magnesium oxide, hydroxyapatite, chitosan, barium sulfate, and silica additives in PMMA on the mechanical, thermal, and cell functional performance of PMMA. American Society for Testing and Materials standard three-point bend flexural and fracture tests were conducted to determine the flexural strength, flexural modulus, and fracture toughness of the different PMMA samples. A custom-made temperature measurement system was used to determine maximum curing temperature and the time needed for each PMMA sample to reach its maximum curing temperature. Osteoblast adhesion and proliferation experiments were performed to determine cell viability using the different PMMA cements. We found that flexural strength and fracture toughness were significantly greater for PMMA specimens that incorporated silica than for the other specimens. All additives prolonged the time taken to reach maximum curing temperature and significantly improved cell adhesion of the PMMA samples. The results of this study could be useful for improving the union of implant-PMMA or bone-PMMA interfaces by incorporating nanoparticles into PMMA cement for orthopedic and orthodontic applications. PMID:24920906

  16. Effect of additive particles on mechanical, thermal, and cell functioning properties of poly(methyl methacrylate) cement.

    PubMed

    Khandaker, Morshed; Vaughan, Melville B; Morris, Tracy L; White, Jeremiah J; Meng, Zhaotong

    2014-01-01

    The most common bone cement material used clinically today for orthopedic surgery is poly(methyl methacrylate) (PMMA). Conventional PMMA bone cement has several mechanical, thermal, and biological disadvantages. To overcome these problems, researchers have investigated combinations of PMMA bone cement and several bioactive particles (micrometers to nanometers in size), such as magnesium oxide, hydroxyapatite, chitosan, barium sulfate, and silica. A study comparing the effect of these individual additives on the mechanical, thermal, and cell functional properties of PMMA would be important to enable selection of suitable additives and design improved PMMA cement for orthopedic applications. Therefore, the goal of this study was to determine the effect of inclusion of magnesium oxide, hydroxyapatite, chitosan, barium sulfate, and silica additives in PMMA on the mechanical, thermal, and cell functional performance of PMMA. American Society for Testing and Materials standard three-point bend flexural and fracture tests were conducted to determine the flexural strength, flexural modulus, and fracture toughness of the different PMMA samples. A custom-made temperature measurement system was used to determine maximum curing temperature and the time needed for each PMMA sample to reach its maximum curing temperature. Osteoblast adhesion and proliferation experiments were performed to determine cell viability using the different PMMA cements. We found that flexural strength and fracture toughness were significantly greater for PMMA specimens that incorporated silica than for the other specimens. All additives prolonged the time taken to reach maximum curing temperature and significantly improved cell adhesion of the PMMA samples. The results of this study could be useful for improving the union of implant-PMMA or bone-PMMA interfaces by incorporating nanoparticles into PMMA cement for orthopedic and orthodontic applications. PMID:24920906

  17. Estimation of the Heat Capacities of Organic Liquids as a Function of Temperature using Group Additivity. I. Hydrocarbon Compounds

    NASA Astrophysics Data System (ADS)

    Růžička, Vlastimil; Domalski, Eugene S.

    1993-05-01

    A second-order group additivity method has been developed for the estimation of the heat capacity of liquid hydrocarbons as a function of temperature in the range from the melting temperature to the normal boiling temperature. The temperature dependence of group contributions and structural corrections has been represented by a polynomial expression. The adjustable parameters in the polynomials have been calculated using a weighted least squares minimization procedure. Recommended heat capacities from a large compilation of critically evaluated data that contains over 1300 organic liquids served as a database both for the development and testing of the method.

  18. Novel real function based method to construct heterogeneous porous scaffolds and additive manufacturing for use in medical engineering.

    PubMed

    Yang, Nan; Tian, Yanling; Zhang, Dawei

    2015-11-01

    Heterogeneous porous scaffolds have important applications in biomedical engineering, as they can mimic the structures of natural tissues to achieve the corresponding properties. Here, we introduce a new and easy to implement real function based method for constructing complex, heterogeneous porous structures, including hybrid structures, stochastic structures, functionally gradient structures, and multi-scale structures, or their combinations (e.g., hybrid multi-scale structures). Based on micro-CT data, a femur-mimetic structure with gradient morphology was constructed using our method and fabricated using stereolithography. Results showed that our method could generate gradient porosity or gradient specific surfaces and be sufficiently flexible for use with micro-CT data and additive manufacturing (AM) techniques. PMID:26320819

  19. Differing Roles of Functional Movement Variability as Experience Increases in Gymnastics

    PubMed Central

    Busquets, Albert; Marina, Michel; Davids, Keith; Angulo-Barroso, Rosa

    2016-01-01

    gymnasts). Longswing assessment allowed us to evaluate inter-trial variability in representative performance context. Coordination variability presented two different configurations across experience levels depending on the variable of interest: either a U-shaped or a L- or \\-shaped graph. Increased inter-trial variability of the functional phase events offered flexibility to adapt the longswing performance in the advanced gymnasts, while decreasing variability in arm-trunk coordination modes was critical to improve longswing and to achieve the most advanced level. In addition, the relationship between variability measures and the global performance outcome (i.e. the swing amplitude) revealed different functional roles of movement variability (exploratory or restrictive) as a function of changes in experience levels. PMID:27274664

  20. Differing Roles of Functional Movement Variability as Experience Increases in Gymnastics.

    PubMed

    Busquets, Albert; Marina, Michel; Davids, Keith; Angulo-Barroso, Rosa

    2016-06-01

    gymnasts). Longswing assessment allowed us to evaluate inter-trial variability in representative performance context.Coordination variability presented two different configurations across experience levels depending on the variable of interest: either a U-shaped or a L- or \\-shaped graph.Increased inter-trial variability of the functional phase events offered flexibility to adapt the longswing performance in the advanced gymnasts, while decreasing variability in arm-trunk coordination modes was critical to improve longswing and to achieve the most advanced level.In addition, the relationship between variability measures and the global performance outcome (i.e. the swing amplitude) revealed different functional roles of movement variability (exploratory or restrictive) as a function of changes in experience levels. PMID:27274664

  1. The Potential Role of Motor Unit Number Estimation as an Additional Diagnostic and Prognostic Value in Canine Neurology

    PubMed Central

    Kauder, Julia; Petri, Susanne; Tipold, Andrea; Stein, Veronika M.

    2015-01-01

    Motor unit number estimation (MUNE) is an electrophysiological technique to assess the number of motor units innervating a single muscle or muscle group of interest. It may quantify axonal loss in any disease involving injury or degeneration of ventral horn cells or motor axons. Since MUNE has rarely been used in veterinary medicine, our study aimed to evaluate its potential role as an additional diagnostic and prognostic parameter in canine neurology. Therefore, we examined five healthy dogs and seven dogs suffering from diseases that necessitated general anesthesia for further diagnostics and treatment and that were not expected to interfere with the results of electrodiagnostic testing. By using the incremental technique to study MUNE in the cranial tibial muscle, we determined the number of motor units, the size of the compound muscle action potential, and the mean size of individual motor unit potentials of each dog as well as the mean values for each group. Moreover, we studied the correlation between these parameters. Taking the results into consideration, we addressed the difficulties and limitations of this technique. We, furthermore, pointed out possible fields of application for MUNE in canine neurology, and emphasized several aspects that future studies should focus on when applying MUNE to canine patients. PMID:26664980

  2. Additional stratifications in the equatorial F region at dawn and dusk during geomagnetic storms: Role of electrodynamics

    NASA Astrophysics Data System (ADS)

    Sreeja, V.; Balan, N.; Ravindran, Sudha; Pant, Tarun Kumar; Sridharan, R.; Bailey, G. J.

    2009-08-01

    The role of electrodynamics in producing additional stratifications in the equatorial F region (F 3 layer) at dawn and dusk during geomagnetic storms is discussed. Two cases of F 3 layer at dawn (0600-0730 LT on 5 October 2000 and 8 December 2000) and one case of F 3 layer at dusk (1600-1730 LT on 5 October 2000) are observed, for the first time, by the digital ionosonde at the equatorial station Trivandrum (8.5°N 77°E dip ˜ 0.5°N) in India. The unusual F 3 layers occurred during the geomagnetic storms and are associated with southward turning of interplanetary magnetic field B z , suggesting that eastward prompt penetration electric field could be the main cause of the F 3 layers. The dawn F 3 layer on 5 October is modeled using the Sheffield University Plasmasphere-Ionosphere Model by using the E × B drift estimated from the real height variation of the ionospheric peak during the morning period. The model qualitatively reproduces the dawn F 3 layer. While the existing F 2 layer rapidly drifts upward and forms the F 3 layer and topside ledge, a new layer forming at lower heights develops into the normal F 2 layer.

  3. Stressors, coping resources, functioning, and role limitations among older korean immigrants: gender differences.

    PubMed

    Lee, Kyoung Hag; GlenMaye, Linnea Flynn

    2014-01-01

    This study explored the differential impacts of stressors and coping resources on the functioning and roles of 246 older Korean immigrant men and women. Older Korean immigrant women were significantly more likely than men to have acculturation and socioeconomic stressors, physical/social functioning problems, and role limitations. English-language barriers and lack of transportation were significantly related to lower functioning and higher role limitations of older Korean women compared to those of older men. Providing social and health care services with bilingual and transportation services to older Korean immigrant women is recommended to increase their physical/social functioning and role performance. PMID:24483283

  4. The Relationship Between Cognitive Function and Life Space: The Potential Role of Personal Control Beliefs

    PubMed Central

    Sartori, Andrea C.; Wadley, Virginia G.; Clay, Olivio J.; Parisi, Jeanine M.; Rebok, George W.; Crowe, Michael

    2011-01-01

    We examined the relationship of cognitive and functional measures with life space (a measure of spatial mobility examining extent of movement within a person’s environment) in older adults, and investigated the potential moderating role of personal control beliefs. Internal control beliefs reflect feelings of competence and personal agency, while attributions of external control imply a more dependent or passive point of view. Participants were 2,737 adults from the ACTIVE study, with a mean age of 74 years. Females comprised 76% of the sample, with good minority representation (27% African American). In multiple regression models controlling for demographic factors, cognitive domains of memory, reasoning, and processing speed were significantly associated with life space (p<.001 for each), and reasoning ability appeared most predictive (B=.117). Measures of everyday function also showed significant associations with life space, independent from the traditional cognitive measures. Interactions between cognitive function and control beliefs were tested, and external control beliefs moderated the relationship between memory and life space, with the combination of high objective memory and low external control beliefs yielding the highest life space (t=−2.07; p=.039). In conclusion, older adults with better cognitive function have a larger overall life space. Performance-based measures of everyday function may also be useful in assessing the functional outcome of life space. Additionally, subjective external control beliefs may moderate the relationship between objective cognitive function and life space. Future studies examining the relationships between these factors longitudinally appear worthwhile to further elucidate the interrelationships of cognitive function, control beliefs, and life space. PMID:21875217

  5. Response of Functional Structure of Soil Microbial Community to Multi-level Nitrogen Additions on the Central Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Zhang, G.; Yuan, Y.

    2015-12-01

    The use of fossil fuels and fertilizers has increased the amount of biologically reactive nitrogen in the atmosphere over the past century. Tibet is the one of the most threatened regions by nitrogen deposition, thus understanding how its microbial communities function maybe of high importance to predicting microbial responses to nitrogen deposition. Here we describe a short-time nitrogen addition conducted in an alpine steppe ecosystem to investigate the response of functional structure of soil microbial community to multi-level nitrogen addition. Using a GeoChip 4.0, we showed that functional diversities and richness of functional genes were unchanged at low level of nitrogen fertilizer inputs (<20 kg N ha-1 yr-1), but significantly decreased at higher nitrogen fertilizer inputs (>=40 kg N ha-1 yr-1). Detrended correspondence analysis indicated that the functional structure of microbial communities was markedly different across the nitrogen gradients. Most C degradation genes whose abundances significantly increased under elevated N fertilizer were those involved in the degradation of relatively labile C (starch, hemicellulose, cellulose), whereas the abundance of certain genes involved in the degradation of recalcitrant C (i.e. lignin) was largely decreased (such as manganese peroxidase, mnp). The results suggest that the elevated N fertilization rates might significantly accelerate the labile C degradation, but might not spur recalcitrant C degradation. The combined effect of gdh and ureC genes involved in N cycling appeared to shift the balance between ammonia and organic N toward organic N ammonification and hence increased the N mineralization potential. Moreover, Urease directly involved in urea mineralization significantly increased. Lastly, Canonical correspondence analysis showed that soil (TOC+NH4++NO3-+NO2-+pH) and plant (Aboveground plant productivity + Shannon Diversity) variables could explain 38.9% of the variation of soil microbial community

  6. Evidence for a Role of Executive Functions in Learning Biology

    ERIC Educational Resources Information Center

    Rhodes, Sinéad M.; Booth, Josephine N.; Campbell, Lorna Elise; Blythe, Richard A.; Wheate, Nial J.; Delibegovic, Mirela

    2014-01-01

    Research examining cognition and science learning has focused on working memory, but evidence implicates a broader set of executive functions. The current study examined executive functions and learning of biology in young adolescents. Fifty-six participants, aged 12-13?years, completed tasks of working memory (Spatial Working Memory), inhibition…

  7. The Role of Inhibitory Functioning in Children's Reading Skills

    ERIC Educational Resources Information Center

    Booth, Josephine N.; Boyle, James M. E.

    2009-01-01

    Executive functions, including inhibition, have been implicated in children's reading ability. This study investigates whether children's performance on an inhibition task is more indicative of reading ability than a measure of another executive function, that is, planning. Fifty-three male participants were administered a reading test and tests…

  8. The role of rabbit meat as functional food.

    PubMed

    Dalle Zotte, Antonella; Szendro, Zsolt

    2011-07-01

    Increasing consumer knowledge of the link between diet and health has raised the awareness and demand for functional food ingredients. Meat and its derivatives may be considered functional foods to the extent that they contain numerous compounds thought to be functional. This review will attempt to outline the excellent nutritional and dietetic properties of rabbit meat and offer an overview of the studies performed on the strategies adopted to improve the functional value of rabbit meat. Dietary manipulation has been seen to be very effective in increasing the levels of essential FA, EPA, DHA, CLA, branched chain FA, vitamin E, and selenium in rabbit meat. Dietary fortification with vitamin E or natural products such as oregano essential oil, chia seed oil, and Spirulina platensis microalga seem promising in improving the oxidative stability of rabbit meat while also adding functional ingredients. PMID:21392894

  9. Health and role functioning: the use of focus groups in the development of an item bank

    PubMed Central

    Bjorner, Jakob B.

    2013-01-01

    Background Role functioning is an important part of health-related quality of life. However, assessment of role functioning is complicated by the wide definition of roles and by fluctuations in role participation across the life-span. The aim of this study is to explore variations in role functioning across the lifespan using qualitative approaches, to inform the development of a role functioning item bank and to pilot test sample items from the bank. Methods Eight focus groups were conducted with a convenience sample of 38 English-speaking adults recruited in Rhode Island. Participants were stratified by gender and four age groups. Focus groups were taped, transcribed, and analyzed for thematic content. Results Participants of all ages identified family roles as the most important. There was age variation in the importance of social life roles, with younger and older adults rating them as more important. Occupational roles were identified as important by younger and middle-aged participants. The potential of health problems to affect role participation was recognized. Participants found the sample items easy to understand, response options identical in meaning and preferred five response choices. Conclusions Participants identified key aspects of role functioning and provided insights on their perception of the impact of health on their role participation. These results will inform item bank generation. PMID:20047086

  10. Functional relationships between leaf hydraulics and leaf economic traits in response to nutrient addition in subtropical tree species.

    PubMed

    Villagra, Mariana; Campanello, Paula I; Bucci, Sandra J; Goldstein, Guillermo

    2013-12-01

    Leaves can be both a hydraulic bottleneck and a safety valve against hydraulic catastrophic dysfunctions, and thus changes in traits related to water movement in leaves and associated costs may be critical for the success of plant growth. A 4-year fertilization experiment with nitrogen (N) and phosphorus (P) addition was done in a semideciduous Atlantic forest in northeastern Argentina. Saplings of five dominant canopy species were grown in similar gaps inside the forests (five control and five N + P addition plots). Leaf lifespan (LL), leaf mass per unit area (LMA), leaf and stem vulnerability to cavitation, leaf hydraulic conductance (K(leaf_area) and K(leaf_mass)) and leaf turgor loss point (TLP) were measured in the five species and in both treatments. Leaf lifespan tended to decrease with the addition of fertilizers, and LMA was significantly higher in plants with nutrient addition compared with individuals in control plots. The vulnerability to cavitation of leaves (P50(leaf)) either increased or decreased with the nutrient treatment depending on the species, but the average P50(leaf) did not change with nutrient addition. The P50(leaf) decreased linearly with increasing LMA and LL across species and treatments. These trade-offs have an important functional significance because more expensive (higher LMA) and less vulnerable leaves (lower P50(leaf)) are retained for a longer period of time. Osmotic potentials at TLP and at full turgor became more negative with decreasing P50(leaf) regardless of nutrient treatment. The K(leaf) on a mass basis was negatively correlated with LMA and LL, indicating that there is a carbon cost associated with increased water transport that is compensated by a longer LL. The vulnerability to cavitation of stems and leaves were similar, particularly in fertilized plants. Leaves in the species studied may not function as safety valves at low water potentials to protect the hydraulic pathway from water stress-induced cavitation

  11. Additional Saturday rehabilitation improves functional independence and quality of life and reduces length of stay: a randomized controlled trial

    PubMed Central

    2013-01-01

    Background Many inpatients receive little or no rehabilitation on weekends. Our aim was to determine what effect providing additional Saturday rehabilitation during inpatient rehabilitation had on functional independence, quality of life and length of stay compared to 5 days per week of rehabilitation. Methods This was a multicenter, single-blind (assessors) randomized controlled trial with concealed allocation and 12-month follow-up conducted in two publically funded metropolitan inpatient rehabilitation facilities in Melbourne, Australia. Patients were eligible if they were adults (aged ≥18 years) admitted for rehabilitation for any orthopedic, neurological or other disabling conditions excluding those admitted for slow stream rehabilitation/geriatric evaluation and management. Participants were randomly allocated to usual care Monday to Friday rehabilitation (control) or to Monday to Saturday rehabilitation (intervention). The additional Saturday rehabilitation comprised physiotherapy and occupational therapy. The primary outcomes were functional independence (functional independence measure (FIM); measured on an 18 to 126 point scale), health-related quality of life (EQ-5D utility index; measured on a 0 to 1 scale, and EQ-5D visual analog scale; measured on a 0 to 100 scale), and patient length of stay. Outcome measures were assessed on admission, discharge (primary endpoint), and at 6 and 12 months post discharge. Results We randomly assigned 996 adults (mean (SD) age 74 (13) years) to Monday to Saturday rehabilitation (n = 496) or usual care Monday to Friday rehabilitation (n = 500). Relative to admission scores, intervention group participants had higher functional independence (mean difference (MD) 2.3, 95% confidence interval (CI) 0.5 to 4.1, P = 0.01) and health-related quality of life (MD 0.04, 95% CI 0.01 to 0.07, P = 0.009) on discharge and may have had a shorter length of stay by 2 days (95% CI 0 to 4, P = 0.1) when compared to

  12. Elucidating the Severity of Preclinical Traumatic Brain Injury Models: A Role for Functional Assessment?

    PubMed Central

    Turner, Ryan C.; VanGilder, Reyna L.; Naser, Zachary J.; Lucke-Wold, Brandon P.; Bailes, Julian E.; Matsumoto, Rae R.; Huber, Jason D.; Rosen, Charles L.

    2016-01-01

    Background Concussion remains a symptom-based diagnosis clinically, yet preclinical studies investigating traumatic brain injury, of which concussion is believed to represent a ‘mild’ form, emphasize histological endpoints with functional assessments often minimized or ignored all together. Recently, clinical studies have identified the importance of cognitive and neuropsychiatric symptoms, in addition to somatic complaints, following concussion. How these findings may translate to preclinical studies is unclear at present. Objective To address the contrasting endpoints utilized clinically compared to those in preclinical studies and the potential role of functional assessments in a commonly used model of diffuse axonal injury (DAI).. Methods Animals were subjected to DAI using the impact-acceleration model. Functional and behavioral assessments were conducted over 1 week following DAI prior to completion of histological assessment at 1-week post-DAI. Results We show, despite the suggestion that this model represents concussive injury, no functional impairments as determined using common measures of motor, sensorimotor, cognitive, and neuropsychiatric function following injury over the course of 1 week. The lack of functional deficits is in sharp contrast to neuropathologic findings indicating neural degeneration, astrocyte reactivity, and microglial activation. Conclusion Future studies are needed to identify functional assessments, neurophysiologic techniques, and imaging assessments more apt to distinguish differences following so-called ‘mild’ traumatic brain injury (TBI) in preclinical models and determine whether these models are truly studying concussive or subconcussive injury. These studies are needed to not only understand mechanism of injury and production of subsequent deficits, but also for rigorous evaluation of potential therapeutic agents. PMID:24448183

  13. Nutritional, Health, and Technological Functionality of Lupin Flour Addition to Bread and Other Baked Products: Benefits and Challenges.

    PubMed

    Villarino, C B J; Jayasena, V; Coorey, R; Chakrabarti-Bell, S; Johnson, S K

    2016-01-01

    Lupin is an undervalued legume despite its high protein and dietary fiber content and potential health benefits. This review focuses on the nutritional value, health benefits, and technological effects of incorporating lupin flour into wheat-based bread. Results of clinical studies suggest that consuming lupin compared to wheat bread and other baked products reduce chronic disease risk markers; possibly due to increased protein and dietary fiber and bioactive compounds. However, lupin protein allergy has also been recorded. Bread quality has been improved when 10% lupin flour is substituted for refined wheat flour; possibly due to lupin-wheat protein cross-linking assisting bread volume and the high water-binding capacity (WBC) of lupin fiber delaying staling. Above 10% substitution appears to reduce bread quality due to lupin proteins low elasticity and the high WBC of its dietary fiber interrupting gluten network development. Gaps in understanding of the role of lupin flour in bread quality include the optimal formulation and processing conditions to maximize lupin incorporation, role of protein cross-linking, antistaling functionality, and bioactivity of its γ-conglutin protein. PMID:25675266

  14. Psychiatric Function and Roles in an Indian Health Program Context.

    ERIC Educational Resources Information Center

    Smith, Margaret Ann

    1990-01-01

    Relates the experiences of a non-Indian psychiatrist as she became part of the mental health team in an urban Indian health care center. Reflects on the evolution of her varied roles and the importance of cultural sensitivity. Includes three case examples of American Indian psychotherapy patients. (Author/SV)

  15. School Personnel Perceptions of Professional School Counselor Role and Function

    ERIC Educational Resources Information Center

    Coles, Caron N.

    2013-01-01

    The purpose of this research study was to examine the attitudes held by school-based administrators, teachers, and professional school counselors regarding ideal and actual roles of the professional school counselor. The survey instrument utilized in this research study, the PSCRFA, is grounded in the ASCA model and reflective of current school…

  16. Role Conflict in Women as a Function of Marital Status

    ERIC Educational Resources Information Center

    Nevill, Dorothy; Damico, Sandra

    1975-01-01

    Questionnaires on eight role conflict categories (time management, relations with husband, household management, financial, child care, expectations for self, expectations of others, and guilt) were administered to 518 women. Marital status was found to be a significant variable with married women expressing more conflict than did other women.…

  17. The role of Eph receptors in lens function and disease

    PubMed Central

    SON, Alexander I.; PARK, Jeong Eun; ZHOU, RenPing

    2014-01-01

    Cataract is the single largest contributor to blindness in the world, with the disease having a strong genetic component. In recent years the Eph family of receptor tyrosine kinases has been identified as a key regulator in lens clarity. In this review we discuss the roles of the Eph receptors in lens biology and cataract development. PMID:22645087

  18. The Roles and Functions of the Rehabilitation Counselor Revisited.

    ERIC Educational Resources Information Center

    Berven, Norman L.

    1979-01-01

    Reexamined the eight duty factors identified by Muthard and Salomone, which have been viewed as a definitive description of rehabilitation counselor role behavior. Data were reanalyzed using cluster analysis. Original results were replicated with modifications, increasing the meaningfulness of the description of rehabilitation counselor role…

  19. Phosphazene additives

    SciTech Connect

    Harrup, Mason K; Rollins, Harry W

    2013-11-26

    An additive comprising a phosphazene compound that has at least two reactive functional groups and at least one capping functional group bonded to phosphorus atoms of the phosphazene compound. One of the at least two reactive functional groups is configured to react with cellulose and the other of the at least two reactive functional groups is configured to react with a resin, such as an amine resin of a polycarboxylic acid resin. The at least one capping functional group is selected from the group consisting of a short chain ether group, an alkoxy group, or an aryloxy group. Also disclosed are an additive-resin admixture, a method of treating a wood product, and a wood product.

  20. Catalytic functionalities of supported sulfides. I. Effect of support and additives on the CoMo catalyst

    SciTech Connect

    Muralidhar, G.; Massoth, F.E.; Shabtai, J.

    1984-01-01

    C-S hydrogenolysis (HDS) of thiophene, hydrogenation (HYD) of 1-hexene, and hydrocracking (HCG) of 2,4,4-trimethyl-1-pentene, were used as separate model test reactions to differentiate and assess the catalytic functionalities of sulfided CoMo catalysts, and their dependence on the nature of the support and incorporation of additives. Rate constants and relative catalyst activities for these three reaction types were determined. HDS and HYD activities of CoMo supported on different types of Al/sub 2/O/sub 3/ were higher, while the HCG activity was lower compared with CoMo supported on SiO/sub 2/-Al/sub 2/O/sub 3/, SiO/sub 2/-MgO, or TiO/sub 2/. For SiO/sub 2/-Al/sub 2/O/sub 3/ supports both HDS and HYD activities decreased with increase in SiO/sub 2/ content from 10 to 75%, while HCG activity showed the opposite trend. Additives to a finished CoMo catalyst at 0.5% level caused variations in HDS and HCG activities, while HYD was essentially unaffected. HDS was promoted by NH/sub 4/HF/sub 2/ and NH/sub 4/Cl, but depressed by NaNO/sub 3/, Ca(NO/sub 3/)/sub 2/, and H/sub 3/BO/sub 3/. HCG was promoted by NH/sub 4/HF/sub 2/, NH/sub 4/Cl, and H/sub 3/BO/sub 3/. Additives at 5% level, prior to or after CoMo impregnation, showed a strong depressing effect on HDS and a lesser effect on HYD, while HCG was strongly promoted by NH/sub 4/HF/sub 2/, Ti isopropoxide, and H/sub 3/BO/sub 3/. The changes in catalytic functionalities are rationalized in terms of different interactions between CoMo phase, support, and additives. 3 tables, 1 figure.

  1. A Functional Role for Anopheles gambiae Arrestin1 in Olfactory Signal Transduction

    PubMed Central

    Walker, William B.; Smith, Elaine M.; Jan, Taha; Zwiebel, L.J.

    2008-01-01

    Insect sensory arrestins act to desensitize visual and olfactory signal transduction pathways, as evidenced by the phenotypic effects of mutations in the genes encoding both Arr1 and Arr2 in Drosophila melanogaster. To assess whether such arrestins play similar roles in other, more medically relevant dipterans, we examined the ability of Anopheles gambiae sensory arrestin homologues AgArr1 and AgArr2 to rescue phenotypes associated with an olfactory deficit observed in D. melanogaster arrestin mutants. Of these, only AgArr1 facilitated significant phenotypic rescue of the corresponding Drosophila arr mutant olfactory phenotype, consistent with the view that functional orthology is shared by these Arr1 homologues. These results represent the first step in the functional characterization of AgArr1, which is highly expressed in olfactory appendages of An. gambiae in which it is likely to play an essential role in olfactory signal transduction. In addition to providing insight into the common elements of the peripheral olfactory system of dipterans, this work validates the importance of AgArr1 as a potential target for novel anti-malaria strategies that focus on olfactory-based behaviors in An. gambiae. PMID:18328499

  2. Role of CGRP-Receptor Component Protein (RCP) in CLR/RAMP Function

    PubMed Central

    Dickerson, Ian M.

    2016-01-01

    The receptor for calcitonin gene-related peptide (CGRP) and adrenomedullin (AM) requires an intracellular peripheral membrane protein named CGRP-receptor component protein (RCP) for signaling. RCP is required for CGRP and AM receptor signaling, and it has recently been discovered that RCP enables signaling by binding directly to the receptor. RCP is present in most immortalized cell lines, but in vivo RCP expression is limited to specific subsets of cells, usually co-localizing with CGRP-containing neurons. RCP protein expression correlates with CGRP efficacy in vivo, suggesting that RCP regulates CGRP signaling in vivo as it does in cell culture. RCP is usually identified in cytoplasm or membranes of cells, but recently has been observed in nucleus of neurons, suggesting an additional transcriptional role for RCP in cell function. Together, these data support an essential role for RCP in CGRP and AM receptor function, in which RCP expression enhances signaling of the CGRP or AM receptor, and therefore increases the efficacy of CGRP and AM in vivo. PMID:23745704

  3. ERAP1 structure, function and pathogenetic role in ankylosing spondylitis and other MHC-associated diseases.

    PubMed

    Alvarez-Navarro, Carlos; López de Castro, José A

    2014-01-01

    The endoplasmic reticulum aminopeptidase 1 (ERAP1) is a multifunctional enzyme involved in the final processing of Major Histocompatibility Complex class I (MHC-I) ligands and with a significant influence in the stability and immunological properties of MHC-I proteins. ERAP1 polymorphism is associated with ankylosing spondylitis among HLA-B27-positive individuals and the altered enzymatic activity of natural variants has significant effects on the HLA-B27 peptidome, suggesting a critical pathogenetic role of peptides in this disease. Likewise, the association of ERAP1 with other MHC-I associated disorders and its epistasis with their susceptibility MHC alleles point out to a general role of the MHC-I peptidome in these diseases. The functional interaction between ERAP1 and HLA-B27 or other MHC-I molecules may be related to the processing of specific epitopes, or to a more general peptide-dependent influence on other biological features of the MHC-I proteins. In addition, from a consideration of the reported functions of ERAP1, including its involvement in angiogenesis and macrophage activation, a more complex and multi-level influence in the inflammatory and immune pathways operating in these diseases cannot be ruled out. PMID:23916068

  4. The role of executive function in children's competent adjustment to middle school.

    PubMed

    Jacobson, Lisa A; Williford, Amanda P; Pianta, Robert C

    2011-01-01

    Executive function (EF) skills play an important role in children's cognitive and social functioning. These skills develop throughout childhood, concurrently with a number of developmental transitions and challenges. One of these challenges is the transition from elementary into middle-level schools, which has the potential to significantly disrupt children's academic and social trajectories. However, little is known about the role of EF in children's adjustment during this transition. This study investigated the relation between children's EF skills, assessed both before and during elementary school, and sixth grade academic and social competence. In addition, the influences of the type of school setting attended in sixth grade on children's academic and behavioral outcomes were examined. EF assessed prior to and during elementary school significantly predicted sixth grade competence, as rated by teachers and parents, in both academic and social domains, after controlling for background characteristics. The interactions between type of school setting and EF skills were significant: Parents tended to report more behavioral problems and less regulatory control in children with weaker EF skills who were attending middle school. In contrast, teachers reported greater academic and behavioral difficulty in students with poorer EF attending elementary school settings. In conclusion, children's performance-based EF skills significantly affect adjustment to the academic and behavioral demands of sixth grade, with parent report suggesting greater difficulty for children with poorer EF in settings where children are provided with less external supports (e.g., middle school). PMID:21246422

  5. The Role of Executive Function in Children’s Competent Adjustment to Middle School

    PubMed Central

    Jacobson, Lisa A.; Williford, Amanda P.; Pianta, Robert C.

    2012-01-01

    Executive function (EF) skills play an important role in children’s cognitive and social functioning. These skills develop throughout childhood, concurrently with a number of developmental transitions and challenges. One of these challenges is the transition from elementary into middle-level schools, which has the potential to significantly disrupt children’s academic and social trajectories. However, little is known about the role of EF in children’s adjustment during this transition. This study investigated the relation between children’s EF skills, assessed both before and during elementary school, and sixth grade academic and social competence. In addition, the influences of the type of school setting attended in sixth grade on children’s academic and behavioral outcomes were examined. EF assessed prior to and during elementary school significantly predicted sixth grade competence, as rated by teachers and parents, in both academic and social domains, after controlling for background characteristics. The interactions between type of school setting and EF skills were significant: parents tended to report more behavioral problems and less regulatory control in children with weaker EF skills who were attending middle school. In contrast, teachers reported greater academic and behavioral difficulty in students with poorer EF attending elementary school settings. In conclusion, children’s performance-based EF skills significantly affect adjustment to the academic and behavioral demands of sixth grade, with parent report suggesting greater difficulty for children with poorer EF in settings where children are provided with less external supports (e.g., middle school). PMID:21246422

  6. Thai and Korean Students' Perceptions about the Roles and Functions of School Psychologists

    ERIC Educational Resources Information Center

    Tangdhanakanond, Kamonwan; Lee, Dong Hun

    2014-01-01

    The purpose of the present study was to compare Thai and Korean college students on their perceptions of the roles and functions of school psychologists. One hundred and ninety-three Thai college students and 238 Korean counterparts participated in this study. Students rated the importance of various roles/functions of a school psychologist and…

  7. Functional Role of Adult Hippocampal Neurogenesis as a Therapeutic Strategy for Mental Disorders

    PubMed Central

    Mohammed Qasim Hussaini, Syed; Rigby, Michael J.; Jang, Mi-Hyeon

    2012-01-01

    Adult neurogenesis, the process of generating new neurons from neural stem cells, plays significant roles in synaptic plasticity, memory, and mood regulation. In the mammalian brain, it continues to occur well into adulthood in discrete regions, namely, the hippocampus and olfactory bulb. During the past decade, significant progress has been made in understanding the mechanisms regulating adult hippocampal neurogenesis and its role in the etiology of mental disorders. In addition, adult hippocampal neurogenesis is highly correlated with the remission of the antidepressant effect. In this paper, we discuss three major psychiatric disorders, depression, schizophrenia, and drug addiction, in light of preclinical evidence used in establishing the neurobiological significance of adult neurogenesis. We interpret the significance of these results and pose questions that remain unanswered. Potential treatments which include electroconvulsive therapy, deep brain stimulation, chemical antidepressants, and exercise therapy are discussed. While consensus lacks on specific mechanisms, we highlight evidence which indicates that these treatments may function via an increase in neural progenitor proliferation and changes to the hippocampal circuitry. Establishing a significant role of adult neurogenesis in the pathogenicity of psychiatric disorders may hold the key to potential strategies toward effective treatment. PMID:23346419

  8. The Functional Role of Neural Oscillations in Non-Verbal Emotional Communication.

    PubMed

    Symons, Ashley E; El-Deredy, Wael; Schwartze, Michael; Kotz, Sonja A

    2016-01-01

    Effective interpersonal communication depends on the ability to perceive and interpret nonverbal emotional expressions from multiple sensory modalities. Current theoretical models propose that visual and auditory emotion perception involves a network of brain regions including the primary sensory cortices, the superior temporal sulcus (STS), and orbitofrontal cortex (OFC). However, relatively little is known about how the dynamic interplay between these regions gives rise to the perception of emotions. In recent years, there has been increasing recognition of the importance of neural oscillations in mediating neural communication within and between functional neural networks. Here we review studies investigating changes in oscillatory activity during the perception of visual, auditory, and audiovisual emotional expressions, and aim to characterize the functional role of neural oscillations in nonverbal emotion perception. Findings from the reviewed literature suggest that theta band oscillations most consistently differentiate between emotional and neutral expressions. While early theta synchronization appears to reflect the initial encoding of emotionally salient sensory information, later fronto-central theta synchronization may reflect the further integration of sensory information with internal representations. Additionally, gamma synchronization reflects facilitated sensory binding of emotional expressions within regions such as the OFC, STS, and, potentially, the amygdala. However, the evidence is more ambiguous when it comes to the role of oscillations within the alpha and beta frequencies, which vary as a function of modality (or modalities), presence or absence of predictive information, and attentional or task demands. Thus, the synchronization of neural oscillations within specific frequency bands mediates the rapid detection, integration, and evaluation of emotional expressions. Moreover, the functional coupling of oscillatory activity across multiples

  9. The Functional Role of Neural Oscillations in Non-Verbal Emotional Communication

    PubMed Central

    Symons, Ashley E.; El-Deredy, Wael; Schwartze, Michael; Kotz, Sonja A.

    2016-01-01

    Effective interpersonal communication depends on the ability to perceive and interpret nonverbal emotional expressions from multiple sensory modalities. Current theoretical models propose that visual and auditory emotion perception involves a network of brain regions including the primary sensory cortices, the superior temporal sulcus (STS), and orbitofrontal cortex (OFC). However, relatively little is known about how the dynamic interplay between these regions gives rise to the perception of emotions. In recent years, there has been increasing recognition of the importance of neural oscillations in mediating neural communication within and between functional neural networks. Here we review studies investigating changes in oscillatory activity during the perception of visual, auditory, and audiovisual emotional expressions, and aim to characterize the functional role of neural oscillations in nonverbal emotion perception. Findings from the reviewed literature suggest that theta band oscillations most consistently differentiate between emotional and neutral expressions. While early theta synchronization appears to reflect the initial encoding of emotionally salient sensory information, later fronto-central theta synchronization may reflect the further integration of sensory information with internal representations. Additionally, gamma synchronization reflects facilitated sensory binding of emotional expressions within regions such as the OFC, STS, and, potentially, the amygdala. However, the evidence is more ambiguous when it comes to the role of oscillations within the alpha and beta frequencies, which vary as a function of modality (or modalities), presence or absence of predictive information, and attentional or task demands. Thus, the synchronization of neural oscillations within specific frequency bands mediates the rapid detection, integration, and evaluation of emotional expressions. Moreover, the functional coupling of oscillatory activity across multiples

  10. On the role of general system theory for functional neuroimaging

    PubMed Central

    Stephan, Klaas Enno

    2004-01-01

    One of the most important goals of neuroscience is to establish precise structure–function relationships in the brain. Since the 19th century, a major scientific endeavour has been to associate structurally distinct cortical regions with specific cognitive functions. This was traditionally accomplished by correlating microstructurally defined areas with lesion sites found in patients with specific neuropsychological symptoms. Modern neuroimaging techniques with high spatial resolution have promised an alternative approach, enabling non-invasive measurements of regionally specific changes of brain activity that are correlated with certain components of a cognitive process. Reviewing classic approaches towards brain structure–function relationships that are based on correlational approaches, this article argues that these approaches are not sufficient to provide an understanding of the operational principles of a dynamic system such as the brain but must be complemented by models based on general system theory. These models reflect the connectional structure of the system under investigation and emphasize context-dependent couplings between the system elements in terms of effective connectivity. The usefulness of system models whose parameters are fitted to measured functional imaging data for testing hypotheses about structure–function relationships in the brain and their potential for clinical applications is demonstrated by several empirical examples. PMID:15610393

  11. Estimation of the Heat Capacities of Organic Liquids as a Function of Temperature Using Group Additivity. An Amendment

    NASA Astrophysics Data System (ADS)

    Zábranský, Milan; Růžička, Vlastimil

    2004-12-01

    An amendment to a second-order group additivity method for the estimation of the heat capacity of pure organic liquids as a function of temperature in the range from the melting temperature to the normal boiling temperature is reported. The temperature dependence of various group contributions and structural corrections is represented by a series of second order polynomial expressions. The group contribution parameters have been developed from an extended database of more than 1800 recommended heat capacity values. The present method should be more versatile and more accurate than the previous one [Růžička and Domalski, J. Phys. Chem. Ref. Data 22, 597, 619 (1993)] due to the use of a larger database and an improved procedure for parameter calculation.

  12. Functional Role of Neural Injury in Obstructive Sleep Apnea

    PubMed Central

    Saboisky, Julian P.; Butler, Jane E.; Gandevia, Simon C.; Eckert, Danny J.

    2012-01-01

    The causes of obstructive sleep apnea (OSA) are multifactorial. Neural injury affecting the upper airway muscles due to repetitive exposure to intermittent hypoxia and/or mechanical strain resulting from snoring and recurrent upper airway closure have been proposed to contribute to OSA disease progression. Multiple studies have demonstrated altered sensory and motor function in patients with OSA using a variety of neurophysiological and histological approaches. However, the extent to which the alterations contribute to impairments in upper airway muscle function, and thus OSA disease progression, remains uncertain. This brief review, primarily focused on data in humans, summarizes: (1) the evidence for upper airway sensorimotor injury in OSA and (2) current understanding of how these changes affect upper airway function and their potential to change OSA progression. Some unresolved questions including possible treatment targets are noted. PMID:22715333

  13. Role of FTO in Adipocyte Development and Function: Recent Insights

    PubMed Central

    Merkestein, Myrte; Sellayah, Dyan

    2015-01-01

    In 2007, FTO was identified as the first genome-wide association study (GWAS) gene associated with obesity in humans. Since then, various animal models have served to establish the mechanistic basis behind this association. Many earlier studies focussed on FTO's effects on food intake via central mechanisms. Emerging evidence, however, implicates adipose tissue development and function in the causal relationship between perturbations in FTO expression and obesity. The purpose of this mini review is to shed light on these new studies of FTO function in adipose tissue and present a clearer picture of its impact on obesity susceptibility. PMID:26788058

  14. Transcription regulation of nuclear receptor PXR: Role of SUMO-1 modification and NDSM in receptor function.

    PubMed

    Priyanka; Kotiya, Deepak; Rana, Manjul; Subbarao, N; Puri, Niti; Tyagi, Rakesh K

    2016-01-15

    Pregnane & Xenobiotic Receptor (PXR) is one of the 48 members of the nuclear receptor superfamily of ligand-modulated transcription factors. PXR plays an important role in metabolism and elimination of diverse noxious endobiotics and xenobiotics. Like in case of some nuclear receptors its function may also be differentially altered, positively or negatively, by various post-translational modifications. In this context, regulation of PXR function by SUMOylation is the subject of present investigation. Here, we report that human PXR is modified by SUMO-1 resulting in its enhanced transcriptional activity. RT-PCR analysis showed that PXR SUMOylation in presence of rifampicin also enhances the endogenous expression levels of key PXR-regulated genes like CYP3A4, CYP2C9, MDR1 and UGT1A1. In addition, mammalian two-hybrid assay exhibited enhanced interaction between PXR and co-activator SRC-1. EMSA results revealed that SUMOylation has no influence on the DNA binding ability of PXR. In silico analysis suggested that PXR protein contains four putative SUMOylation sites, centered at K108, K129, K160 and K170. In addition to this, we identified the presence of NDSM (Negative charge amino acid Dependent SUMOylation Motif) in PXR. Substitution of all its four putative lysine residues along with NDSM abolished the effect of SUMO-1-mediated transactivation function of PXR. Furthermore, we show that interaction between PXR and E2-conjugation enzyme UBCh9, an important step for implementation of SUMOylation event, was reduced in case of NDSM mutant PXRD115A. Overall, our results suggest that SUMOylation at specific sites on PXR protein are involved in enhancement of transcription function of this receptor. PMID:26549688

  15. Composite scaffolds for osteochondral repair obtained by combination of additive manufacturing, leaching processes and hMSC-CM functionalization.

    PubMed

    Díaz Lantada, Andrés; Alarcón Iniesta, Hernán; García-Ruíz, Josefa Predestinación

    2016-02-01

    Articular repair is a relevant and challenging area for the emerging fields of tissue engineering and biofabrication. The need of significant gradients of properties, for the promotion of osteochondral repair, has led to the development of several families of composite biomaterials and scaffolds, using different effective approaches, although a perfect solution has not yet been found. In this study we present the design, modeling, rapid manufacturing and in vitro testing of a composite scaffold aimed at osteochondral repair. The presented composite scaffold stands out for having a functional gradient of density and stiffness in the bony phase, obtained in titanium by means of computer-aided design combined with additive manufacture using selective laser sintering. The chondral phase is obtained by sugar leaching, using a PDMS matrix and sugar as porogen, and is joined to the bony phase during the polymerization of PDMS, therefore avoiding the use of supporting adhesives or additional intermediate layers. The mechanical performance of the construct is biomimetic and the stiffness values of the bony and chondral phases can be tuned to the desired applications, by means of controlled modifications of different parameters. A human mesenchymal stem cell (h-MSC) conditioned medium (CM) is used for improving scaffold response. Cell culture results provide relevant information regarding the viability of the composite scaffolds used. PMID:26652367

  16. Resonance scattering and radiation force calculations for an elastic cylinder using the translational addition theorem for cylindrical wave functions

    SciTech Connect

    Mitri, F. G.

    2015-09-15

    The standard Resonance Scattering Theory (RST) of plane waves is extended for the case of any two-dimensional (2D) arbitrarily-shaped monochromatic beam incident upon an elastic cylinder with arbitrary location using an exact methodology based on Graf’s translational addition theorem for the cylindrical wave functions. The analysis is exact as it does not require numerical integration procedures. The formulation is valid for any cylinder of finite size and material that is immersed in a nonviscous fluid. Partial-wave series expansions (PWSEs) for the incident, internal and scattered linear pressure fields are derived, and the analysis is further extended to obtain generalized expressions for the on-axis and off-axis acoustic radiation force components. The wave-fields are expressed using generalized PWSEs involving the beam-shape coefficients (BSCs) and the scattering coefficients of the cylinder. The off-axial BSCs are expressed analytically in terms of an infinite PWSE with emphasis on the translational offset distance d. Numerical computations are considered for a zeroth-order quasi-Gaussian beam chosen as an example to illustrate the analysis. Acoustic resonance scattering directivity diagrams are calculated by subtracting an appropriate background from the expression of the scattered pressure field. In addition, computations for the radiation force exerted on an elastic cylinder centered on the axis of wave propagation of the beam, and shifted off-axially are analyzed and discussed.

  17. Improved synthesis of a highly fluorinated boronic ester as dual functional additive for lithium-ion batteries.

    SciTech Connect

    Weng, W.; Zhang, Z.; Schlueter, J. A.; Redfern, P. C.; Curtiss, L. A.; Amine, K.

    2011-02-01

    The electrolyte additive 2-(pentafluorophenyl)-tetrafluoro-1,3,2-benzodioxaborole (PFPTFBB, 1) was found to have a reversible redox potential at 4.43 V vs. Li{sup +}/Li. This compound can function as an overcharge protection additive as well as anion receptor for lithium-ion batteries. It has drawn a great deal of interest from industry, but its use in relatively large quantities is limited by the production challenges of tetrafluorocatechol (TFC, 3), which is the key starting chemical for the synthesis of PFPTFBB. As part of a continuous effort in our research toward improving the safety of lithium-ion batteries, we have performed the synthesis of TFC and optimized its synthesis process. The X-ray single-crystal structures of TFC and the intermediate product 5,6,7,8-tetrafluoro-1,4-benzodioxane (4) during the process of PFPTFBB synthesis are reported for the first time. Also presented is the lithium ion cell performance of PFPTFBB as redox shuttle in various electrolyte systems.

  18. Functional role of stromal interaction molecule 1 (STIM1) in vascular smooth muscle cells

    SciTech Connect

    Takahashi, Yoichiro; Watanabe, Hiroyuki; Murakami, Manabu; Ono, Kyoichi; Munehisa, Yoshiko; Koyama, Takashi; Nobori, Kiyoshi; Iijima, Toshihiko; Ito, Hiroshi

    2007-10-05

    We investigated the functional role of STIM1, a Ca{sup 2+} sensor in the endoplasmic reticulum (ER) that regulates store-operated Ca{sup 2+} entry (SOCE), in vascular smooth muscle cells (VSMCs). STIM1 was mainly localized at the ER and plasma membrane. The knockdown of STIM1 expression by small interfering (si) RNA drastically decreased SOCE. In contrast, an EF-hand mutant of STIM1, STIM1{sup E87A}, produced a marked increase in SOCE, which was abolished by co-transfection with siRNA to transient receptor potential canonical 1 (TRPC1). In addition, transfection with siRNA against STIM1 suppressed phosphorylation of cAMP-responsive element binding protein (CREB) and cell growth. These results suggest that STIM1 is an essential component of SOCE and that it is involved in VSMC proliferation.

  19. Role of Ubiquitylation in Controlling Suppressor of Cytokine Signalling 3 (SOCS3) Function and Expression

    PubMed Central

    Williams, Jamie J. L.; Munro, Kirsten M. A.; Palmer, Timothy M.

    2014-01-01

    The realisation that unregulated activation of the Janus kinase–signal transducer and activator of transcription (JAK–STAT) pathway is a key driver of a wide range of diseases has identified its components as targets for therapeutic intervention by small molecule inhibitors and biologicals. In this review, we discuss JAK-STAT signalling pathway inhibition by the inducible inhibitor “suppressor of cytokine signaling 3 (SOCS3), its role in diseases such as myeloproliferative disorders, and its function as part of a multi-subunit E3 ubiquitin ligase complex. In addition, we highlight potential applications of these insights into SOCS3-based therapeutic strategies for management of conditions such as vascular re-stenosis associated with acute vascular injury, where there is strong evidence that multiple processes involved in disease progression could be attenuated by localized potentiation of SOCS3 expression levels. PMID:24886706

  20. Advisory Councils: Role, Function, Status, Responsibility and Operation. Position Paper.

    ERIC Educational Resources Information Center

    McQuay, Paul L.; Watters, Edmond A.

    After defining trade advisory committees as groups of individuals who have been selected because of their special knowledge and expertise to give advice on education programs, this report identifies the functions of the advisory committee in the areas of educational objectives, instructional content, program evaluation, review of equipment and…

  1. Parenting and Adolescent Adjustment: The Role of Parental Reflective Function

    ERIC Educational Resources Information Center

    Benbassat, Naomi; Priel, Beatriz

    2012-01-01

    Reflective function (RF) is the capacity to reflect on one's own mental experiences and those of others. This study examined the relationship between parental RF and adolescent adjustment. One hundred and five adolescents, aged 14-18, and their mothers and fathers were interviewed and completed questionnaires during home visits. We measured…

  2. The Role of Family Functioning in Bipolar Disorder in Families

    ERIC Educational Resources Information Center

    Du Rocher Schudlich, Tina D.; Youngstrom, Eric A.; Calabrese, Joseph R.; Findling, Robert L.

    2008-01-01

    Investigated the association between family functioning and conflict and their links with mood disorder in parents and with children's risk for bipolar disorder. Participants were 272 families with a child between the ages of 5-17 years. Parents' history of psychiatric diagnoses and children's current diagnoses were obtained via semi-structured…

  3. Emotion Understanding in Preschool Children: The Role of Executive Functions

    ERIC Educational Resources Information Center

    Martins, Eva Costa; Osório, Ana; Veríssimo, Manuela; Martins, Carla

    2016-01-01

    This investigation was aimed at studying the relations between executive functions (EFs) and categorical emotion understanding while controlling for preschoolers' IQ, language ability and theory of mind (ToM). Specifically, we wanted to analyse the association between emotion understanding and set shifting, due to the lack of studies with this EF.…

  4. The Role of Functional Form in Causal-Based Categorization

    ERIC Educational Resources Information Center

    Rehder, Bob

    2015-01-01

    Two experiments tested how the "functional form" of the causal relations that link features of categories affects category-based inferences. Whereas "independent causes" can each bring about an effect by themselves, "conjunctive causes" all need to be present for an effect to occur. The causal model view of category…

  5. Morphology predicts species' functional roles and their degree of specialization in plant-frugivore interactions.

    PubMed

    Dehling, D Matthias; Jordano, Pedro; Schaefer, H Martin; Böhning-Gaese, Katrin; Schleuning, Matthias

    2016-01-27

    Species' functional roles in key ecosystem processes such as predation, pollination or seed dispersal are determined by the resource use of consumer species. An interaction between resource and consumer species usually requires trait matching (e.g. a congruence in the morphologies of interaction partners). Species' morphology should therefore determine species' functional roles in ecological processes mediated by mutualistic or antagonistic interactions. We tested this assumption for Neotropical plant-bird mutualisms. We used a new analytical framework that assesses a species's functional role based on the analysis of the traits of its interaction partners in a multidimensional trait space. We employed this framework to test (i) whether there is correspondence between the morphology of bird species and their functional roles and (ii) whether morphologically specialized birds fulfil specialized functional roles. We found that morphological differences between bird species reflected their functional differences: (i) bird species with different morphologies foraged on distinct sets of plant species and (ii) morphologically distinct bird species fulfilled specialized functional roles. These findings encourage further assessments of species' functional roles through the analysis of their interaction partners, and the proposed analytical framework facilitates a wide range of novel analyses for network and community ecology. PMID:26817779

  6. Determining firms׳ utility functions and competitive roles from data on market shares using Lotka-Volterra models.

    PubMed

    Marasco, A; Picucci, A; Romano, A

    2016-06-01

    In this article, we include data on historical and estimated market shares of two markets. In particular, we include annual data on the market shares of the Japanese beer market (1963-2000) and biannual data on the market shares of the mobile phones market in Greece (1998-2007). In addition, we estimate monthly data on market shares for both markets. We show how this data can be used to derive firms' utility functions and their competitive roles. PMID:27054182

  7. Determining firms׳ utility functions and competitive roles from data on market shares using Lotka–Volterra models

    PubMed Central

    Marasco, A.; Picucci, A.; Romano, A.

    2016-01-01

    In this article, we include data on historical and estimated market shares of two markets. In particular, we include annual data on the market shares of the Japanese beer market (1963–2000) and biannual data on the market shares of the mobile phones market in Greece (1998–2007). In addition, we estimate monthly data on market shares for both markets. We show how this data can be used to derive firms’ utility functions and their competitive roles. PMID:27054182

  8. Role of the Contralesional Hemisphere in Post-Stroke Recovery of Upper Extremity Motor Function

    PubMed Central

    Buetefisch, Cathrin M.

    2015-01-01

    Identification of optimal treatment strategies to improve recovery is limited by the incomplete understanding of the neurobiological principles of recovery. Motor cortex (M1) reorganization of the lesioned hemisphere (ipsilesional M1) plays a major role in post-stroke motor recovery and is a primary target for rehabilitation therapy. Reorganization of M1 in the hemisphere contralateral to the stroke (contralesional M1) may, however, serve as an additional source of cortical reorganization and related recovery. The extent and outcome of such reorganization depends on many factors, including lesion size and time since stroke. In the chronic phase post-stroke, contralesional M1 seems to interfere with motor function of the paretic limb in a subset of patients, possibly through abnormally increased inhibition of lesioned M1 by the contralesional M1. In such patients, decreasing contralesional M1 excitability by cortical stimulation results in improved performance of the paretic limb. However, emerging evidence suggests a potentially supportive role of contralesional M1. After infarction of M1 or its corticospinal projections, there is abnormally increased excitatory neural activity and activation in contralesional M1 that correlates with favorable motor recovery. Decreasing contralesional M1 excitability in these patients may result in deterioration of paretic limb performance. In animal stroke models, reorganizational changes in contralesional M1 depend on the lesion size and rehabilitation treatment and include long-term changes in neurotransmitter systems, dendritic growth, and synapse formation. While there is, therefore, some evidence that activity in contralesional M1 will impact the extent of motor function of the paretic limb in the subacute and chronic phase post-stroke and may serve as a new target for rehabilitation treatment strategies, the precise factors that specifically influence its role in the recovery process remain to be defined. PMID:26528236

  9. Functional analysis of centipede development supports roles for Wnt genes in posterior development and segment generation.

    PubMed

    Hayden, Luke; Schlosser, Gerhard; Arthur, Wallace

    2015-01-01

    The genes of the Wnt family play important and highly conserved roles in posterior growth and development in a wide range of animal taxa. Wnt genes also operate in arthropod segmentation, and there has been much recent debate regarding the relationship between arthropod and vertebrate segmentation mechanisms. Due to its phylogenetic position, body form, and possession of many (11) Wnt genes, the centipede Strigamia maritima is a useful system with which to examine these issues. This study takes a functional approach based on treatment with lithium chloride, which causes ubiquitous activation of canonical Wnt signalling. This is the first functional developmental study performed in any of the 15,000 species of the arthropod subphylum Myriapoda. The expression of all 11 Wnt genes in Strigamia was analyzed in relation to posterior development. Three of these genes, Wnt11, Wnt5, and WntA, were strongly expressed in the posterior region and, thus, may play important roles in posterior developmental processes. In support of this hypothesis, LiCl treatment of S. maritima embryos was observed to produce posterior developmental defects and perturbations in AbdB and Delta expression. The effects of LiCl differ depending on the developmental stage treated, with more severe effects elicited by treatment during germband formation than by treatment at later stages. These results support a role for Wnt signalling in conferring posterior identity in Strigamia. In addition, data from this study are consistent with the hypothesis of segmentation based on a "clock and wavefront" mechanism operating in this species. PMID:25627713

  10. The Role of Sleep in Emotional Brain Function

    PubMed Central

    Goldstein, Andrea N.; Walker, Matthew P.

    2014-01-01

    Rapidly emerging evidence continues to describe an intimate and causal relationship between sleep and emotional brain function. These findings are mirrored by longstanding clinical observations demonstrating that nearly all mood and anxiety disorders co-occur with one or more sleep abnormalities. This review aims to (1) provide a synthesis of recent findings describing the emotional brain and behavioral benefits triggered by sleep, and conversely, the detrimental impairments following a lack of sleep, (2) outline a proposed framework in which sleep, and specifically rapid-eye movement (REM) sleep, supports a process of affective brain homeostasis, optimally preparing the organism for next-day social and emotional functioning, and (3) describe how this hypothesized framework can explain the prevalent relationships between sleep and psychiatric disorders, with a particular focus on post-traumatic stress disorder and major depression. PMID:24499013

  11. Aging and immune function: a possible role for growth hormone.

    PubMed

    Gelato, M C

    1996-01-01

    Elderly individuals have four to five times the case rate of cancer, tuberculosis and herpes zoster and six to seven times the fatality rate from pneumonia compared to young adults. This may be causally related to two changes that occur with aging, i.e. decreased growth hormone (GH)/insulin-like growth factor-1 (IGF-1) production and decreased immune function. Data from our laboratory as well as others have shown that, based on either GH secretory dynamics or IGF-1 levels, approximately 40% of adults aged 60 and older are GH deficient. In the same population of subjects, immune function decreases such that there is a decline in cell-mediated and humoral immune responsiveness. Some of these immune deficits have been shown to be reversed in humans and primates by GH and/or IGF-1 treatment. This paper will review some of these data. PMID:8742118

  12. Gas7-Deficient Mouse Reveals Roles in Motor Function and Muscle Fiber Composition during Aging

    PubMed Central

    Huang, Bo-Tsang; Chang, Pu-Yuan; Su, Ching-Hua; Chao, Chuck C.-K.; Lin-Chao, Sue

    2012-01-01

    Background Growth arrest-specific gene 7 (Gas7) has previously been shown to be involved in neurite outgrowth in vitro; however, its actual role has yet to be determined. To investigate the physiological function of Gas7 in vivo, here we generated a Gas7-deficient mouse strain with a labile Gas7 mutant protein whose functions are similar to wild-type Gas7. Methodology/Principal Findings Our data show that aged Gas7-deficient mice have motor activity defects due to decreases in the number of spinal motor neurons and in muscle strength, of which the latter may be caused by changes in muscle fiber composition as shown in the soleus. In cross sections of the soleus of Gas7-deficient mice, gross morphological features and levels of myosin heavy chain I (MHC I) and MHC II markers revealed significantly fewer fast fibers. In addition, we found that nerve terminal sprouting, which may be associated with slow and fast muscle fiber composition, was considerably reduced at neuromuscular junctions (NMJ) during aging. Conclusions/Significance These findings indicate that Gas7 is involved in motor neuron function associated with muscle strength maintenance. PMID:22662195

  13. New roles for “old” microRNAs in nervous system function and disease

    PubMed Central

    Hartl, Marion; Grunwald Kadow, Ilona C.

    2013-01-01

    Since their discovery, microRNAs became prominent candidates providing missing links on how to explain the developmental and phenotypical variation within one species or among different species. In addition, microRNAs were implicated in diseases such as neurodegeneration and cancer. More recently, the regulation of animal behavior was shown to be influenced by microRNAs. In spite of their numerous functions, only a few microRNAs were discovered by using classic genetic approaches. Due to the very mild or redundant phenotypes of most microRNAs or their genomic location within introns of other genes many regulatory microRNAs were missed. In this review, we focus on three microRNAs first identified in a forward genetic screen in invertebrates for their essential function in animal development, namely bantam, let-7, and miR-279. All three are essential for survival, are not located in introns of other genes, and are highly conserved among species. We highlight their important functions in the nervous system and discuss their emerging roles, especially during nervous system disease and behavior. PMID:24399929

  14. A role for matrix stiffness in the regulation of cardiac side population cell function.

    PubMed

    Qiu, Yiling; Bayomy, Ahmad F; Gomez, Marcus V; Bauer, Michael; Du, Ping; Yang, Yanfei; Zhang, Xin; Liao, Ronglih

    2015-05-01

    The mechanical properties of the local microenvironment may have important influence on the fate and function of adult tissue progenitor cells, altering the regenerative process. This is particularly critical following a myocardial infarction, in which the normal, compliant myocardial tissue is replaced with fibrotic, stiff scar tissue. In this study, we examined the effects of matrix stiffness on adult cardiac side population (CSP) progenitor cell behavior. Ovine and murine CSP cells were isolated and cultured on polydimethylsiloxane substrates, replicating the elastic moduli of normal and fibrotic myocardium. Proliferation capacity and cell cycling were increased in CSP cells cultured on the stiff substrate with an associated reduction in cardiomyogeneic differentiation and accelerated cell ageing. In addition, culture on stiff substrate stimulated upregulation of extracellular matrix and adhesion proteins gene expression in CSP cells. Collectively, we demonstrate that microenvironment properties, including matrix stiffness, play a critical role in regulating progenitor cell functions of endogenous resident CSP cells. Understanding the effects of the tissue microenvironment on resident cardiac progenitor cells is a critical step toward achieving functional cardiac regeneration. PMID:25724498

  15. A role for matrix stiffness in the regulation of cardiac side population cell function

    PubMed Central

    Qiu, Yiling; Bayomy, Ahmad F.; Gomez, Marcus V.; Bauer, Michael; Du, Ping; Yang, Yanfei; Zhang, Xin

    2015-01-01

    The mechanical properties of the local microenvironment may have important influence on the fate and function of adult tissue progenitor cells, altering the regenerative process. This is particularly critical following a myocardial infarction, in which the normal, compliant myocardial tissue is replaced with fibrotic, stiff scar tissue. In this study, we examined the effects of matrix stiffness on adult cardiac side population (CSP) progenitor cell behavior. Ovine and murine CSP cells were isolated and cultured on polydimethylsiloxane substrates, replicating the elastic moduli of normal and fibrotic myocardium. Proliferation capacity and cell cycling were increased in CSP cells cultured on the stiff substrate with an associated reduction in cardiomyogeneic differentiation and accelerated cell ageing. In addition, culture on stiff substrate stimulated upregulation of extracellular matrix and adhesion proteins gene expression in CSP cells. Collectively, we demonstrate that microenvironment properties, including matrix stiffness, play a critical role in regulating progenitor cell functions of endogenous resident CSP cells. Understanding the effects of the tissue microenvironment on resident cardiac progenitor cells is a critical step toward achieving functional cardiac regeneration. PMID:25724498

  16. The role of the NG2 proteoglycan in OPC and CNS network function.

    PubMed

    Sakry, Dominik; Trotter, Jacqueline

    2016-05-01

    In the normal mammalian CNS, the NG2 proteoglycan is expressed by oligodendrocyte precursor cells (OPC) but not by any other neural cell-type. NG2 is a type-1 membrane protein, exerting multiple roles in the CNS including intracellular signaling within the OPC, with effects on migration, cytoskeleton interaction and target gene regulation. It has been recently shown that the extracellular region of NG2, in addition to an adhesive function, acts as a soluble ECM component with the capacity to alter defined neuronal network properties. This region of NG2 is thus endowed with neuromodulatory properties. In order to generate biologically active fragments yielding these properties, the sequential cleavage of the NG2 protein by α- and γ-secretases occurs. The basal level of constitutive cleavage is stimulated by neuronal network activity. This processing leads to 4 major NG2 fragments which all have been associated with distinct biological functions. Here we summarize these functions, focusing on recent discoveries and their implications for the CNS. This article is part of a Special Issue entitled SI:NG2-glia(Invited only). PMID:26100334

  17. Diverse Roles of Axonemal Dyneins in Drosophila Auditory Neuron Function and Mechanical Amplification in Hearing

    PubMed Central

    Karak, Somdatta; Jacobs, Julie S.; Kittelmann, Maike; Spalthoff, Christian; Katana, Radoslaw; Sivan-Loukianova, Elena; Schon, Michael A.; Kernan, Maurice J.; Eberl, Daniel F.; Göpfert, Martin C.

    2015-01-01

    Much like vertebrate hair cells, the chordotonal sensory neurons that mediate hearing in Drosophila are motile and amplify the mechanical input of the ear. Because the neurons bear mechanosensory primary cilia whose microtubule axonemes display dynein arms, we hypothesized that their motility is powered by dyneins. Here, we describe two axonemal dynein proteins that are required for Drosophila auditory neuron function, localize to their primary cilia, and differently contribute to mechanical amplification in hearing. Promoter fusions revealed that the two axonemal dynein genes Dmdnah3 (=CG17150) and Dmdnai2 (=CG6053) are expressed in chordotonal neurons, including the auditory ones in the fly’s ear. Null alleles of both dyneins equally abolished electrical auditory neuron responses, yet whereas mutations in Dmdnah3 facilitated mechanical amplification, amplification was abolished by mutations in Dmdnai2. Epistasis analysis revealed that Dmdnah3 acts downstream of Nan-Iav channels in controlling the amplificatory gain. Dmdnai2, in addition to being required for amplification, was essential for outer dynein arms in auditory neuron cilia. This establishes diverse roles of axonemal dyneins in Drosophila auditory neuron function and links auditory neuron motility to primary cilia and axonemal dyneins. Mutant defects in sperm competition suggest that both dyneins also function in sperm motility. PMID:26608786

  18. Aging of the Planning Process: The Role of Executive Functioning

    ERIC Educational Resources Information Center

    Sorel, Olivier; Pennequin, Valerie

    2008-01-01

    This study tested whether the aging of executive functioning is linked to the decline in planning performance. Participants were divided into three groups: group 1 composed of 15 adults with a mean age of 22.7 years, group 2 composed of 15 adults with a mean age of 68.1 years and group 3 composed of 16 adults with a mean age of 78.75 years. Each…

  19. Role of Amine Functionality for CO2 Chemisorption on Silica.

    PubMed

    Hahn, Maximilian W; Jelic, Jelena; Berger, Edith; Reuter, Karsten; Jentys, Andreas; Lercher, Johannes A

    2016-03-01

    The mechanism of CO2 adsorption on primary, secondary, and bibasic aminosilanes synthetically functionalized in porous SiO2 was qualitatively and quantitatively investigated by a combination of IR spectroscopy, thermogravimetry, and quantum mechanical modeling. The mode of CO2 adsorption depends particularly on the nature of the amine group and the spacing between the aminosilanes. Primary amines bonded CO2 preferentially through the formation of intermolecular ammonium carbamates, whereas CO2 was predominantly stabilized as carbamic acid, when interacting with secondary amines. Ammonium carbamate formation requires the transfer of the carbamic acid proton to a second primary amine group to form the ammonium ion and hence two (primary) amine groups are required to bind one CO2 molecule. The higher base strength of secondary amines enables the stabilization of carbamic acid, which is thereby hindered to interact further with nearby amine functions, because their association with Si-OH groups (either protonation or hydrogen bonding) does not allow further stabilization of carbamic acid as carbamate. Steric hindrance of the formation of intermolecular ammonium carbamates leads to higher uptake capacities for secondary amines functionalized in porous SiO2 at higher amine densities. In aminosilanes possessing a primary and a secondary amine group, the secondary amine group tends to be protonated by Si-OH groups and therefore does not substantially interact with CO2. PMID:26700549

  20. Energizing Genetics and Epi-genetics: Role in the Regulation of Mitochondrial Function

    PubMed Central

    Audano, Matteo; Ferrari, Alessandra; Fiorino, Erika; Kuenzl, Martin; Caruso, Donatella; Mitro, Nico; Crestani, Maurizio; Fabiani, Emma De

    2014-01-01

    Energy metabolism and mitochondrial function hold a core position in cellular homeostasis. Oxidative metabolism is regulated at multiple levels, ranging from gene transcription to allosteric modulation. To accomplish the fine tuning of these multiple regulatory circuits, the nuclear and mitochondrial compartments are tightly and reciprocally controlled. The fact that nuclear encoded factors, PPARγ coactivator 1α and mitochondrial transcription factor A, play pivotal roles in the regulation of oxidative metabolism and mitochondrial biogenesis is paradigmatic of this crosstalk. Here we provide an updated survey of the genetic and epigenetic mechanisms involved in the control of energy metabolism and mitochondrial function. Chromatin dynamics highly depends on post-translational modifications occurring at specific amino acids in histone proteins and other factors associated to nuclear DNA. In addition to the well characterized enzymes responsible for histone methylation/demethylation and acetylation/deacetylation, other factors have gone on the “metabolic stage”. This is the case of the new class of α-ketoglutarate-regulated demethylases (Jumonji C domain containing demethylases) and of the NAD+-dependent deacetylases, also known as sirtuins. Moreover, unexpected features of the machineries involved in mitochondrial DNA (mtDNA) replication and transcription, mitochondrial RNA processing and maturation have recently emerged. Mutations or defects of any component of these machineries profoundly affect mitochondrial activity and oxidative metabolism. Finally, recent evidences support the importance of mtDNA packaging in replication and transcription. These observations, along with the discovery that non-classical CpG islands present in mtDNA undergo methylation, indicate that epigenetics also plays a role in the regulation of the mitochondrial genome function. PMID:25646072

  1. Functional role of human immunodeficiency virus type 1 vpu.

    PubMed Central

    Terwilliger, E F; Cohen, E A; Lu, Y C; Sodroski, J G; Haseltine, W A

    1989-01-01

    To investigate the role of vpu in the replication and cytopathicity of human immunodeficiency virus type 1 (HIV-1), infectious proviruses were constructed that were isogenic except for the ability to produce the protein product of vpu. The vpu-encoded protein is shown to decrease the rate of syncytium formation and cell killing in infected CD4+ human T cells, to increase greatly the export of virus particles from infected cells, and to reduce the rate of accumulation of cell-associated viral proteins. The vpu protein complements in trans the defect in a vpu- HIV-1 provirus but does not affect the simian immunodeficiency virus, which lacks vpu. These observations suggest that vpu may contribute to the AIDS epidemic by increasing the transmission efficiency of the virus. Images PMID:2472639

  2. Role of Foxl2 in uterine maturation and function.

    PubMed

    Bellessort, Brice; Bachelot, Anne; Heude, Églantine; Alfama, Gladys; Fontaine, Anastasia; Le Cardinal, Marine; Treier, Mathias; Levi, Giovanni

    2015-06-01

    Foxl2 codes for a forkhead/HNF3 transcription factor essential for follicular maturation and maintenance of ovarian identity. FOXL2 mutations are associated with Blepharophimosis, Ptosis and Epicanthus inversus Syndrome (BPES) characterized by eyelid malformations (types I and II) and premature ovarian insufficiency (type I). We show that Foxl2 is not only expressed by the ovary, but also by other components of the mouse female reproductive tract, including the uterus, the cervix and the oviduct. In the uterus, Foxl2 expression is first observed in the neonatal mesenchyme and, during uterine maturation, persists in the stroma and in the deep inner myometrial layer (IML). In the adult, Foxl2 is expressed in the differentiated stromal layer, but no longer in the myometrium. Conditional deletion of Foxl2 in the postnatal (PN) uterus using Progesterone Receptor-cre (Pgr(cre/+)) mice results in infertility. During PN uterine maturation Pgr(cre/+); Foxl2(flox/flox) mice present a severely reduced thickness of the stroma layer and an hypertrophic, disorganized IML. In adult Pgr(cre/+); Foxl2(flox/flox) mice a supplementary muscular layer is present at the stroma/myometrium border and vascular smooth muscle cells fail to form a coherent layer around uterine arteries. Wnt signalling pathways play a central role in uterine maturation; in Pgr(cre/+); Foxl2(flox/flox) mice, Wnt genes are deregulated suggesting that Foxl2 acts through these signals. In humans, thickening of the IML (also called "junctional zone") is associated with reduced fertility, endometriosis and adenomyosis. Our data suggest that Foxl2 has a crucial role in PN uterine maturation and could help to understand sub-fertility predisposition in women. PMID:25687138

  3. The Historical Role of the Production Function in Economics and Business

    ERIC Educational Resources Information Center

    Gordon, David; Vaughan, Richard

    2011-01-01

    The production function explains a basic technological relationship between scarce resources, or inputs, and output. This paper offers a brief overview of the historical significance and operational role of the production function in business and economics. The origin and development of this function over time is initially explored. Several…

  4. Diabetes and mitochondrial function: Role of hyperglycemia and oxidative stress

    SciTech Connect

    Rolo, Anabela P.; Palmeira, Carlos M. . E-mail: palmeira@ci.uc.pt

    2006-04-15

    Hyperglycemia resulting from uncontrolled glucose regulation is widely recognized as the causal link between diabetes and diabetic complications. Four major molecular mechanisms have been implicated in hyperglycemia-induced tissue damage: activation of protein kinase C (PKC) isoforms via de novo synthesis of the lipid second messenger diacylglycerol (DAG), increased hexosamine pathway flux, increased advanced glycation end product (AGE) formation, and increased polyol pathway flux. Hyperglycemia-induced overproduction of superoxide is the causal link between high glucose and the pathways responsible for hyperglycemic damage. In fact, diabetes is typically accompanied by increased production of free radicals and/or impaired antioxidant defense capabilities, indicating a central contribution for reactive oxygen species (ROS) in the onset, progression, and pathological consequences of diabetes. Besides oxidative stress, a growing body of evidence has demonstrated a link between various disturbances in mitochondrial functioning and type 2 diabetes. Mutations in mitochondrial DNA (mtDNA) and decreases in mtDNA copy number have been linked to the pathogenesis of type 2 diabetes. The study of the relationship of mtDNA to type 2 diabetes has revealed the influence of the mitochondria on nuclear-encoded glucose transporters, glucose-stimulated insulin secretion, and nuclear-encoded uncoupling proteins (UCPs) in {beta}-cell glucose toxicity. This review focuses on a range of mitochondrial factors important in the pathogenesis of diabetes. We review the published literature regarding the direct effects of hyperglycemia on mitochondrial function and suggest the possibility of regulation of mitochondrial function at a transcriptional level in response to hyperglycemia. The main goal of this review is to include a fresh consideration of pathways involved in hyperglycemia-induced diabetic complications.

  5. Cytosolic phospholipase A2: physiological function and role in disease

    PubMed Central

    Leslie, Christina C.

    2015-01-01

    The group IV phospholipase A2 (PLA2) family is comprised of six intracellular enzymes (GIVA, -B, -C, -D, -E, and -F) commonly referred to as cytosolic PLA2 (cPLA2)α, -β, -γ, -δ, -ε, and -ζ. They contain a Ser-Asp catalytic dyad and all except cPLA2γ have a C2 domain, but differences in their catalytic activities and subcellular localization suggest unique regulation and function. With the exception of cPLA2α, the focus of this review, little is known about the in vivo function of group IV enzymes. cPLA2α catalyzes the hydrolysis of phospholipids to arachidonic acid and lysophospholipids that are precursors of numerous bioactive lipids. The regulation of cPLA2α is complex, involving transcriptional and posttranslational processes, particularly increases in calcium and phosphorylation. cPLA2α is a highly conserved widely expressed enzyme that promotes lipid mediator production in human and rodent cells from a variety of tissues. The diverse bioactive lipids produced as a result of cPLA2α activation regulate normal physiological processes and disease pathogenesis in many organ systems, as shown using cPLA2α KO mice. However, humans recently identified with cPLA2α deficiency exhibit more pronounced effects on health than observed in mice lacking cPLA2α, indicating that much remains to be learned about this interesting enzyme. PMID:25838312

  6. Additive loss-of-function proteasome subunit mutations in CANDLE/PRAAS patients promote type I IFN production.

    PubMed

    Brehm, Anja; Liu, Yin; Sheikh, Afzal; Marrero, Bernadette; Omoyinmi, Ebun; Zhou, Qing; Montealegre, Gina; Biancotto, Angelique; Reinhardt, Adam; Almeida de Jesus, Adriana; Pelletier, Martin; Tsai, Wanxia L; Remmers, Elaine F; Kardava, Lela; Hill, Suvimol; Kim, Hanna; Lachmann, Helen J; Megarbane, Andre; Chae, Jae Jin; Brady, Jilian; Castillo, Rhina D; Brown, Diane; Casano, Angel Vera; Gao, Ling; Chapelle, Dawn; Huang, Yan; Stone, Deborah; Chen, Yongqing; Sotzny, Franziska; Lee, Chyi-Chia Richard; Kastner, Daniel L; Torrelo, Antonio; Zlotogorski, Abraham; Moir, Susan; Gadina, Massimo; McCoy, Phil; Wesley, Robert; Rother, Kristina I; Rother, Kristina; Hildebrand, Peter W; Brogan, Paul; Krüger, Elke; Aksentijevich, Ivona; Goldbach-Mansky, Raphaela

    2015-11-01

    Autosomal recessive mutations in proteasome subunit β 8 (PSMB8), which encodes the inducible proteasome subunit β5i, cause the immune-dysregulatory disease chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature (CANDLE), which is classified as a proteasome-associated autoinflammatory syndrome (PRAAS). Here, we identified 8 mutations in 4 proteasome genes, PSMA3 (encodes α7), PSMB4 (encodes β7), PSMB9 (encodes β1i), and proteasome maturation protein (POMP), that have not been previously associated with disease and 1 mutation in PSMB8 that has not been previously reported. One patient was compound heterozygous for PSMB4 mutations, 6 patients from 4 families were heterozygous for a missense mutation in 1 inducible proteasome subunit and a mutation in a constitutive proteasome subunit, and 1 patient was heterozygous for a POMP mutation, thus establishing a digenic and autosomal dominant inheritance pattern of PRAAS. Function evaluation revealed that these mutations variably affect transcription, protein expression, protein folding, proteasome assembly, and, ultimately, proteasome activity. Moreover, defects in proteasome formation and function were recapitulated by siRNA-mediated knockdown of the respective subunits in primary fibroblasts from healthy individuals. Patient-isolated hematopoietic and nonhematopoietic cells exhibited a strong IFN gene-expression signature, irrespective of genotype. Additionally, chemical proteasome inhibition or progressive depletion of proteasome subunit gene transcription with siRNA induced transcription of type I IFN genes in healthy control cells. Our results provide further insight into CANDLE genetics and link global proteasome dysfunction to increased type I IFN production. PMID:26524591

  7. Additive loss-of-function proteasome subunit mutations in CANDLE/PRAAS patients promote type I IFN production

    PubMed Central

    Brehm, Anja; Liu, Yin; Sheikh, Afzal; Marrero, Bernadette; Omoyinmi, Ebun; Zhou, Qing; Montealegre, Gina; Biancotto, Angelique; Reinhardt, Adam; Almeida de Jesus, Adriana; Pelletier, Martin; Tsai, Wanxia L.; Remmers, Elaine F.; Kardava, Lela; Hill, Suvimol; Kim, Hanna; Lachmann, Helen J.; Megarbane, Andre; Chae, Jae Jin; Brady, Jilian; Castillo, Rhina D.; Brown, Diane; Casano, Angel Vera; Gao, Ling; Chapelle, Dawn; Huang, Yan; Stone, Deborah; Chen, Yongqing; Sotzny, Franziska; Lee, Chyi-Chia Richard; Kastner, Daniel L.; Torrelo, Antonio; Zlotogorski, Abraham; Moir, Susan; Gadina, Massimo; McCoy, Phil; Wesley, Robert; Rother, Kristina; Hildebrand, Peter W.; Brogan, Paul; Krüger, Elke; Aksentijevich, Ivona; Goldbach-Mansky, Raphaela

    2015-01-01

    Autosomal recessive mutations in proteasome subunit β 8 (PSMB8), which encodes the inducible proteasome subunit β5i, cause the immune-dysregulatory disease chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature (CANDLE), which is classified as a proteasome-associated autoinflammatory syndrome (PRAAS). Here, we identified 8 mutations in 4 proteasome genes, PSMA3 (encodes α7), PSMB4 (encodes β7), PSMB9 (encodes β1i), and proteasome maturation protein (POMP), that have not been previously associated with disease and 1 mutation in PSMB8 that has not been previously reported. One patient was compound heterozygous for PSMB4 mutations, 6 patients from 4 families were heterozygous for a missense mutation in 1 inducible proteasome subunit and a mutation in a constitutive proteasome subunit, and 1 patient was heterozygous for a POMP mutation, thus establishing a digenic and autosomal dominant inheritance pattern of PRAAS. Function evaluation revealed that these mutations variably affect transcription, protein expression, protein folding, proteasome assembly, and, ultimately, proteasome activity. Moreover, defects in proteasome formation and function were recapitulated by siRNA-mediated knockdown of the respective subunits in primary fibroblasts from healthy individuals. Patient-isolated hematopoietic and nonhematopoietic cells exhibited a strong IFN gene-expression signature, irrespective of genotype. Additionally, chemical proteasome inhibition or progressive depletion of proteasome subunit gene transcription with siRNA induced transcription of type I IFN genes in healthy control cells. Our results provide further insight into CANDLE genetics and link global proteasome dysfunction to increased type I IFN production. PMID:26524591

  8. Re(de)fining the orthographic neighborhood: the role of addition and deletion neighbors in lexical decision and reading.

    PubMed

    Davis, Colin J; Perea, Manuel; Acha, Joana

    2009-10-01

    The influence of addition and deletion neighbors on visual word identification was investigated in four experiments. Experiments 1 and 2 used Spanish stimuli. In Experiment 1, lexical decision latencies were slower and less accurate for words and nonwords with higher-frequency deletion neighbors (e.g., jugar in juzgar), relative to control stimuli. Experiment 2 showed a similar interference effect for words and nonwords with higher-frequency addition neighbors (e.g., conejo, which has the addition neighbor consejo), relative to control stimuli. Experiment 3 replicated this addition neighbor interference effect in a lexical decision experiment with English stimuli. Across all three experiments, interference effects were always evident for addition/deletion neighbors with word-outer overlap, usually present for those with word-initial overlap, but never present for those with word-final overlap. Experiment 4 replicated the addition/deletion neighbor inhibitory effects in a Spanish sentence reading task in which the participants' eye movements were monitored. These findings suggest that conventional orthographic neighborhood metrics should be redefined. In addition to its methodological implications, this conclusion has significant theoretical implications for input coding schemes and the mechanisms underlying word recognition. PMID:19803656

  9. Role of mitochondrial function in cell death and body metabolism.

    PubMed

    Lee, Myung-Shik

    2016-01-01

    Mitochondria are the key players in apoptosis and necrosis. Mitochondrial DNA (mtDNA)-depleted r0 cells were resistant to diverse apoptosis inducers such as TNF-alpha, TNFSF10, staurosporine and p53. Apoptosis resistance was accompanied by the absence of mitochondrial potential loss or cytochrome c translocation. r0 cells were also resistant to necrosis induced by reactive oxygen species (ROS) donors due to upregulation of antioxidant enzymes such as manganese superoxide dismutase. Mitochondria also has a close relationship with autophagy that plays a critical role in the turnover of senescent organelles or dysfunctional proteins and may be included in 'cell death' category. It was demonstrated that autophagy deficiency in insulin target tissues such as skeletal muscle induces mitochondrial stress response, which leads to the induction of FGF21 as a 'mitokine' and affects the whole body metabolism. These results show that mitochondria are not simply the power plants of cells generating ATP, but are closely related to several types of cell death and autophagy. Mitochondria affect various pathophysiological events related to diverse disorders such as cancer, metabolic disorders and aging. PMID:27100503

  10. Thalamus plays a central role in ongoing cortical functioning.

    PubMed

    Sherman, S Murray

    2016-04-01

    Several challenges to current views of thalamocortical processing are offered here. Glutamatergic pathways in thalamus and cortex are divided into two distinct classes: driver and modulator. We suggest that driver inputs are the main conduits of information and that modulator inputs modify how driver inputs are processed. Different driver sources reveal two types of thalamic relays: first order relays receive subcortical driver input (for example, retinal input to the lateral geniculate nucleus), whereas higher order relays (for example, pulvinar) receive driver input from layer 5 of cortex and participate in cortico-thalamo-cortical (or transthalamic) circuits. These transthalamic circuits represent an unappreciated aspect of cortical functioning, which I discuss here. Direct corticocortical connections are often paralleled by transthalamic ones. Furthermore, driver inputs to thalamus, both first and higher order, typically arrive via branching axons, and the transthalamic branch often innervates subcortical motor centers, leading to the suggestion that these inputs to thalamus serve as efference copies. PMID:27021938

  11. Role of Partner Novelty in Sexual Functioning: A Review.

    PubMed

    Morton, Heather; Gorzalka, Boris B

    2015-01-01

    This review investigates whether sexual desire and arousal decline in response to partner familiarity, increase in response to partner novelty, and show differential responding in men and women. These questions were considered through the perspective of two leading evolutionary theories regarding human mating strategies: sexual strategies theory and attachment fertility theory. The hypotheses emerging from these theories were evaluated through a critical analysis of several areas of research including habituation of arousal to erotic stimuli, preferences regarding number of sexual partners, the effect of long-term monogamous relationships on sexual arousal and desire, and prevalence and risk factors associated with extradyadic behavior. The current literature best supports the predictions made by sexual strategies theory in that sexual functioning has evolved to promote short-term mating. Sexual arousal and desire appear to decrease in response to partner familiarity and increase in response to partner novelty in men and women. Evidence to date suggests this effect may be greater in men. PMID:25222339

  12. Hantaviral Proteins: Structure, Functions, and Role in Hantavirus Infection

    PubMed Central

    Muyangwa, Musalwa; Martynova, Ekaterina V.; Khaiboullina, Svetlana F.; Morzunov, Sergey P.; Rizvanov, Albert A.

    2015-01-01

    Hantaviruses are the members of the family Bunyaviridae that are naturally maintained in the populations of small mammals, mostly rodents. Most of these viruses can easily infect humans through contact with aerosols or dust generated by contaminated animal waste products. Depending on the particular Hantavirus involved, human infection could result in either hemorrhagic fever with renal syndrome or in Hantavirus cardiopulmonary syndrome. In the past few years, clinical cases of the Hantavirus caused diseases have been on the rise. Understanding structure of the Hantavirus genome and the functions of the key viral proteins are critical for the therapeutic agents’ research. This paper gives a brief overview of the current knowledge on the structure and properties of the Hantavirus nucleoprotein and the glycoproteins. PMID:26640463

  13. Functional mammalian spliceosomal complex E contains SMN complex proteins in addition to U1 and U2 snRNPs

    PubMed Central

    Makarov, Evgeny M.; Owen, Nicholas; Bottrill, Andrew; Makarova, Olga V.

    2012-01-01

    Spliceosomes remove introns from primary gene transcripts. They assemble de novo on each intron through a series of steps that involve the incorporation of five snRNP particles and multiple non-snRNP proteins. In mammals, all the intermediate complexes have been characterized on one transcript (MINX), with the exception of the very first, complex E. We have purified this complex by two independent procedures using antibodies to either U1-A or PRPF40A proteins, which are known to associate at an early stage of assembly. We demonstrate that the purified complexes are functional in splicing using commitment assays. These complexes contain components expected to be in the E complex and a number of previously unrecognized factors, including survival of motor neurons (SMN) and proteins of the SMN-associated complex. Depletion of the SMN complex proteins from nuclear extracts inhibits formation of the E complex and causes non-productive complexes to accumulate. This suggests that the SMN complex stabilizes the association of U1 and U2 snRNPs with pre-mRNA. In addition, the antibody to PRPF40A precipitated U2 snRNPs from nuclear extracts, indicating that PRPF40A associates with U2 snRNPs. PMID:22110043

  14. α,β-Unsaturated monoterpene acid glucose esters: structural diversity, bioactivities and functional roles.

    PubMed

    Goodger, Jason Q D; Woodrow, Ian E

    2011-12-01

    The glycosylation of lipophilic small molecules produces many important plant secondary metabolites. The majority of these are O-glycosides with relatively fewer occurring as glucose esters of aromatic or aliphatic acids. In particular, monoterpene acid glucose esters have much lower structural diversity and distribution compared to monoterpene glycosides. Nevertheless, there have been over 20 monoterpene acid glucose esters described from trees in the genus Eucalyptus (Myrtaceae) in recent years, all based on oleuropeic acid, menthiafolic acid or both. Here we review all of the glucose esters containing these monoterpenoids identified in plants to date. Many of the compounds contain phenolic aglycones and all contain at least one α,β-unsaturated carbonyl, affording a number of important potential therapeutic reactivities such as anti-tumor promotion, carcinogenesis suppression, and anti-oxidant and anti-inflammatory activities. Additional properties such as cytotoxicity, bitterness, and repellency are suggestive of a role in plant defence, but we also discuss their localization to the exterior of foliar secretory cavity lumina, and suggest they may also protect secretory cells from toxic terpenes housed within these structures. Finally we discuss how the use of a recently developed protocol to isolate secretory cavities in a functional state could be used in conjunction with systems biology approaches to help characterize their biosynthesis and roles in plants. PMID:21945720

  15. Role of the mu opioid receptor in opioid modulation of immune function

    PubMed Central

    Ninković, Jana; Roy, Sabita

    2014-01-01

    SUMMARY Endogenous opioids are synthesized in vivo in order to modulate pain mechanisms and inflammatory pathways. Endogenous and exogenous opioids mediate analgesia in response to painful stimuli by binding to opioid receptors on neuronal cells. However, wide distribution of opioid receptors on tissues and organ systems outside the CNS, such as the cells of the immune system, indicate that opioids are capable of exerting additional effects in the periphery, such as immunomodulation. The increased prevalence of infections in opioid abusers based epidemiological studies further highlights the immunosuppressive effects of opioids. In spite of their many debilitating side effects, prescription opioids remain a gold standard for treatment of chronic pain. Therefore, given the prevalence of opioid use and abuse, opioid mediated immune suppression presents a serious concern in our society today. It is imperative to understand the mechanisms by which exogenous opioids modulate immune processes. In this review we will discuss the role of opioid receptors and their ligands in mediating immune suppressive functions. We will summarize recent studies on direct and indirect opioid modulation of the cells of the immune system as well as the role of opioids in exacerbation of certain disease states. PMID:22170499

  16. Gli-Similar (Glis) Proteins: Their Mechanisms of Action, Physiological Functions, and Roles in Disease

    PubMed Central

    Lichti-Kaiser, Kristin; ZeRuth, Gary; Kang, Hong Soon; Vasanth, Shivakumar; Jetten, Anton M.

    2013-01-01

    Gli-similar (Glis) 1–3 proteins constitute a sub-family of Krüppel-like zinc finger proteins that are closely related to members of the Gli family. Glis proteins have been implicated in several pathologies, including cystic kidney disease, diabetes, hypothyroidism, fibrosis, osteoporosis, psoriasis, and cancer. In humans, a mutation in the Glis2 gene has been linked to the development of nephronophthisis (NPHP), a recessive cystic kidney disease, while mutations in Glis3 lead to an extended multi-system phenotype that includes the development of neonatal diabetes, polycystic kidneys, congenital hypothyroidism, and facial dysmorphism. Glis3 has also been identified as a risk locus for type-1 and type-2 diabetes and additional studies have revealed a role for Glis3 in pancreatic endocrine development, β-cell maintenance, and insulin regulation. Similar to Gli1-3, Glis2 and 3 have been reported to localize to the primary cilium. These studies appear to suggest that Glis proteins are part of a primary cilium-associated signaling pathway(s). It has been hypothesized that Glis proteins are activated through post-translational modifications and subsequently translocate to the nucleus where they regulate transcription by interacting with Glis binding sites in the promoter regions of target genes. This chapter will summarize the current state of knowledge regarding mechanisms of action of the Glis family of proteins, their physiological functions, as well as their roles in disease. PMID:22391303

  17. Aquaporins in the eye: Expression, function, and roles in ocular disease☆

    PubMed Central

    Schey, Kevin L.; Wang, Zhen; Wenke, Jamie L.; Qi, Ying

    2015-01-01

    Background All thirteen known mammalian aquaporins have been detected in the eye. Moreover, aquaporins have been identified as playing essential roles in ocular functions ranging from maintenance of lens and corneal transparency to production of aqueous humor to maintenance of cellular homeostasis and regulation of signal transduction in the retina. Scope of review This review summarizes the expression and known functions of ocular aquaporins and discusses their known and potential roles in ocular diseases. Major conclusions Aquaporins play essential roles in all ocular tissues. Remarkably, not all aquaporin function as a water permeable channel and the functions of many aquaporins in ocular tissues remain unknown. Given their vital roles in maintaining ocular function and their roles in disease, aquaporins represent potential targets for future therapeutic development. General significance Since aquaporins play key roles in ocular physiology, an understanding of these functions is important to improving ocular health and treating diseases of the eye. It is likely that future therapies for ocular diseases will rely on modulation of aquaporin expression and/or function. This article is part of a Special Issue entitled Aquaporins. PMID:24184915

  18. Plasmacytoid dendritic cells: development, functions, and role in atherosclerotic inflammation

    PubMed Central

    Chistiakov, Dimitry A.; Orekhov, Alexander N.; Sobenin, Igor A.; Bobryshev, Yuri V.

    2014-01-01

    Plasmacytoid dendritic cells (pDCs) are a specialized subset of DCs that links innate and adaptive immunity. They sense viral and bacterial pathogens and release high levels of Type I interferons (IFN-I) in response to infection. pDCs were shown to contribute to inflammatory responses in the steady state and in pathology. In atherosclerosis, pDCs are involved in priming vascular inflammation and atherogenesis through production of IFN-I and chemokines that attract inflammatory cells to inflamed sites. pDCs also contribute to the proinflammatory activation of effector T cells, cytotoxic T cells, and conventional DCs. However, tolerogenic populations of pDCs are found that suppress atherosclerosis-associated inflammation through down-regulation of function and proliferation of proinflammatory T cell subsets and induction of regulatory T cells with potent immunomodulatory properties. Notably, atheroprotective tolerogenic DCs could be induced by certain self-antigens or bacterial antigens that suggests for great therapeutic potential of these DCs for development of DC-based anti-atherogenic vaccines. PMID:25120492

  19. Critical role of tissue mast cells in controlling long-term glucose sensor function in vivo.

    PubMed

    Klueh, Ulrike; Kaur, Manjot; Qiao, Yi; Kreutzer, Donald L

    2010-06-01

    Little is known about the specific cells, mediators and mechanisms involved in the loss of glucose sensor function (GSF) in vivo. Since mast cells (MC) are known to be key effector cells in inflammation and wound healing, we hypothesized that MC and their products are major contributors to the skin inflammation and wound healing that controls GSF at sites of sensor implantation. To test this hypothesis we utilized a murine model of continuous glucose monitoring (CGM) in vivo in both normal C57BL/6 mice (mast cell sufficient), as well as mast cell deficient B6.Cg-Kit(W-sh)/HNihrJaeBsmJ (Sash) mice over a 28 day CGM period. As expected, both strains of mice displayed excellent CGM for the first 7 days post sensor implantation (PSI). CGM in the mast cell sufficient C57BL/6 mice was erratic over the remaining 21 days PSI. CGM in the mast cell deficient Sash mice displayed excellent sensor function for the entire 28 day of CGM. Histopathologic evaluation of implantation sites demonstrated that tissue reactions in Sash mice were dramatically less compared to the reactions in normal C57BL/6 mice. Additionally, mast cells were also seen to be consistently associated with the margins of sensor tissue reactions in normal C57BL/6 mice. Finally, direct injection of bone marrow derived mast cells at sites of sensor implantation induced an acute and dramatic loss of sensor function in both C57BL/6 and Sash mice. These results demonstrate the key role of mast cells in controlling glucose sensor function in vivo. PMID:20226521

  20. On the role of covarying functions in stimulus class formation and transfer of function.

    PubMed Central

    Markham, Rebecca G; Markham, Michael R

    2002-01-01

    This experiment investigated whether directly trained covarying functions are necessary for stimulus class formation and transfer of function in humans. Initial class training was designed to establish two respondent-based stimulus classes by pairing two visual stimuli with shock and two other visual stimuli with no shock. Next, two operant discrimination functions were trained to one stimulus of each putative class. The no-shock group received the same training and testing in all phases, except no stimuli were ever paired with shock. The data indicated that skin conductance response conditioning did not occur for the shock groups or for the no-shock group. Tests showed transfer of the established discriminative functions, however, only for the shock groups, indicating the formation of two stimulus classes only for those participants who received respondent class training. The results suggest that transfer of function does not depend on first covarying the stimulus class functions. PMID:12507017

  1. Functional role of progestin and the progesterone receptor in the suppression of spermatogenesis in rodents.

    PubMed

    Lue, Yanhe; Wang, Christina; Lydon, John P; Leung, Andrew; Li, James; Swerdloff, Ronald S

    2013-03-01

    Synthetic progestins such as levonorgestrel (LNG) are used in combination with testosterone (T) in male contraceptive clinical trials to suppress gonadotropins secretion, but whether progestins have additional direct effects on the testis are not known. This study aimed to examine the effect of a potent progestin, (LNG), alone or in combination with testosterone (T) on spermatogenesis in adult rats, and to evaluate the functional role of the progesterone receptors (PRs) in the testis. In comparison with a low dose of LNG treatment in adult rats for 4 weeks, T and T + LNG treatment decreased testicular sperm count to 64.1 and 40.2% of control levels respectively. LNG induced germ cell apoptosis at stages I-IV and XII-XIV; T increased apoptosis at stages VII-VIII; LNG + T treatment induced greater germ cell apoptosis at a wider range of seminiferous epithelial stages. RT-PCR and Western Blots showed that PR was present in testes and up-regulated during suppression of spermatogenesis induced by testicular hormonal deprivation. PR knockout (PRKO) mice had larger testes, greater sperm production, increased numbers of Sertoli and Leydig cells. Suppression of gonadotropin and intratesticular T by GnRH-antagonist treatment induced PR promoter driven LacZ expression in Leydig cells of PRKO mice. This suggests that GnRH-antagonist treatment while inducing germ cell apoptosis also up-regulates PR. We conclude that (i) LNG + T induced greater suppression of spermatogenesis through increase in germ cell apoptosis involving a wider range of seminiferous epithelial stages than either treatment alone, (ii) up-regulation of PR was associated with inhibition of spermatogenesis, (iii) PR knockout mice showed increased sperm production suggesting that testicular PR activated events play a physiological and pharmacological inhibitory role in the testis. These data support the hypothesis that in addition to its known suppressive effects on gonadotropins, progestins may have direct

  2. RNA G-Quadruplexes in the model plant species Arabidopsis thaliana: prevalence and possible functional roles

    PubMed Central

    Mullen, Melissa A.; Olson, Kalee J.; Dallaire, Paul; Major, François; Assmann, Sarah M.; Bevilacqua, Philip C.

    2010-01-01

    Tandem stretches of guanines can associate in hydrogen-bonded arrays to form G-quadruplexes, which are stabilized by K+ ions. Using computational methods, we searched for G-Quadruplex Sequence (GQS) patterns in the model plant species Arabidopsis thaliana. We found ∼1200 GQS with a G3 repeat sequence motif, most of which are located in the intergenic region. Using a Markov modeled genome, we determined that GQS are significantly underrepresented in the genome. Additionally, we found ∼43 000 GQS with a G2 repeat sequence motif; notably, 80% of these were located in genic regions, suggesting that these sequences may fold at the RNA level. Gene Ontology functional analysis revealed that GQS are overrepresented in genes encoding proteins of certain functional categories, including enzyme activity. Conversely, GQS are underrepresented in other categories of genes, notably those for non-coding RNAs such as tRNAs and rRNAs. We also find that genes that are differentially regulated by drought are significantly more likely to contain a GQS. CD-detected K+ titrations performed on representative RNAs verified formation of quadruplexes at physiological K+ concentrations. Overall, this study indicates that GQS are present at unique locations in Arabidopsis and that folding of RNA GQS may play important roles in regulating gene expression. PMID:20860998

  3. Secondary Structure across the Bacterial Transcriptome Reveals Versatile Roles in mRNA Regulation and Function.

    PubMed

    Del Campo, Cristian; Bartholomäus, Alexander; Fedyunin, Ivan; Ignatova, Zoya

    2015-10-01

    Messenger RNA acts as an informational molecule between DNA and translating ribosomes. Emerging evidence places mRNA in central cellular processes beyond its major function as informational entity. Although individual examples show that specific structural features of mRNA regulate translation and transcript stability, their role and function throughout the bacterial transcriptome remains unknown. Combining three sequencing approaches to provide a high resolution view of global mRNA secondary structure, translation efficiency and mRNA abundance, we unraveled structural features in E. coli mRNA with implications in translation and mRNA degradation. A poorly structured site upstream of the coding sequence serves as an additional unspecific binding site of the ribosomes and the degree of its secondary structure propensity negatively correlates with gene expression. Secondary structures within coding sequences are highly dynamic and influence translation only within a very small subset of positions. A secondary structure upstream of the stop codon is enriched in genes terminated by UAA codon with likely implications in translation termination. The global analysis further substantiates a common recognition signature of RNase E to initiate endonucleolytic cleavage. This work determines for the first time the E. coli RNA structurome, highlighting the contribution of mRNA secondary structure as a direct effector of a variety of processes, including translation and mRNA degradation. PMID:26495981

  4. Secondary Structure across the Bacterial Transcriptome Reveals Versatile Roles in mRNA Regulation and Function

    PubMed Central

    Fedyunin, Ivan; Ignatova, Zoya

    2015-01-01

    Messenger RNA acts as an informational molecule between DNA and translating ribosomes. Emerging evidence places mRNA in central cellular processes beyond its major function as informational entity. Although individual examples show that specific structural features of mRNA regulate translation and transcript stability, their role and function throughout the bacterial transcriptome remains unknown. Combining three sequencing approaches to provide a high resolution view of global mRNA secondary structure, translation efficiency and mRNA abundance, we unraveled structural features in E. coli mRNA with implications in translation and mRNA degradation. A poorly structured site upstream of the coding sequence serves as an additional unspecific binding site of the ribosomes and the degree of its secondary structure propensity negatively correlates with gene expression. Secondary structures within coding sequences are highly dynamic and influence translation only within a very small subset of positions. A secondary structure upstream of the stop codon is enriched in genes terminated by UAA codon with likely implications in translation termination. The global analysis further substantiates a common recognition signature of RNase E to initiate endonucleolytic cleavage. This work determines for the first time the E. coli RNA structurome, highlighting the contribution of mRNA secondary structure as a direct effector of a variety of processes, including translation and mRNA degradation. PMID:26495981

  5. Functional and structural roles of residues in the third extramembrane segment of adrenal cytochrome b561.

    PubMed

    Liu, Wen; da Silva, Giordano F Z; Wu, Gang; Palmer, Graham; Tsai, Ah-Lim; Kulmacz, Richard J

    2011-04-19

    Several residues in the third extramembrane segment (EM3) of adrenal cytochrome b(561) have been proposed to be involved in this cytochrome's interaction with ascorbate, but there has been no systematic evaluation of residues in the segment. We used alanine scanning mutagenesis to assess the functional and structural roles of the EM3 residues and several adjacent residues (residues 70-85) in the bovine cytochrome. Each alanine mutant was expressed in a bacterial system, solubilized with detergent, and affinity-purified. The recombinant proteins contained approximately two hemes per monomer and, except for R74A, retained basic functionality (≥ 94% reduced by 20 mM ascorbate). Equilibrium spectrophotometric titrations with ascorbate were used to analyze the α-band line shape and amplitude during reduction of the high- and low-potential heme centers (b(H) and b(L), respectively) and the midpoint ascorbate concentrations for the b(H) and b(L) transitions (C(H) and C(L), respectively). Y73A and K85A markedly narrowed the b(H) α-band peak; other mutants had weaker effects or no effect on b(H) or b(L) spectra. Relative changes in C(H) for the mutants were larger than changes in C(L), with 1.5-2.9-fold increases in C(H) for L70A, L71A, Y73A, R74A, N78A, and K85A. The amounts of functional b(H) and b(L) centers in additional Arg74 mutants, assessed by ascorbate titration and EPR spectroscopy, declined in concert in the following order: wild type > R74K > R74Q > R74T and R74Y > R74E. The results of this first comprehensive experimental test of the proposed roles of EM3 residues have identified residues with a direct or indirect impact on ascorbate interactions, on the environment of the b(H) heme center, and on formation of the native b(H)-b(L) unit. Surprisingly, no individual EM3 residue was by itself indispensable for the interaction with ascorbate, and the role of the segment appears to be more subtle than previously thought. These results also support our

  6. Role of sympathetic nervous system in the entrainment of circadian natural killer cell function

    PubMed Central

    Logan, Ryan; Arjona, Alvaro; Sarkar, Dipak K.

    2010-01-01

    Previous research in our laboratory has demonstrated robust circadian variations of cytokines and cytolytic factors in enriched NK cells from rat spleen, strongly suggesting these functions may be subject to circadian regulation. The SCN mediates timing information to peripheral tissues by both humoral and neural inputs. In particular, noradrenergic (NE) sympathetic nervous system (SNS) terminals innervate the spleen tissue communicating information between central and peripheral systems. However, whether these immune factors are subject to timing information conveyed through neural NE innervation to the spleen remained unknown. Indeed, we were able to characterize a circadian rhythm of NE content in the spleen, supporting the role of the SNS as a conveyor of timing information to splenocytes. By chemically producing a local splenic sympathectomy through guanethidine treatment, the splenic NE rhythm was abolished or shifted as indicated by a blunting of the expected peak at ZT7. Consequently, the daily variations of cytokine, TNF-α, and cytolytic factors, granzyme-B and perforin, in NK cells and splenocytes were altered. Only time-dependent mRNA expression of IFN-γ was altered in splenocytes, but not protein levels in NK cells, suggesting non-neural entrainment cues may be necessary to regulate specific immune factors. In addition, the rhythms of clock genes and proteins, Bmal1 and Per2, in these tissues also displayed significantly altered daily variations. Collectively, these results demonstrate rhythmic NE input to the spleen acts as an entrainment cue to modulate the molecular clock in NK cells and other spleen cells possibly playing a role in regulating the cytokine and cytolytic function of these cells. PMID:20816749

  7. Redefining functional models of basal ganglia organization: role for the posteroventral pallidum in linguistic processing?

    PubMed

    Whelan, Brooke-Mai; Murdoch, Bruce E; Theodoros, Deborah G; Darnell, Ross; Silburn, Peter; Hall, Bruce

    2004-11-01

    Traditionally the basal ganglia have been implicated in motor behavior, as they are involved in both the execution of automatic actions and the modification of ongoing actions in novel contexts. Corresponding to cognition, the role of the basal ganglia has not been defined as explicitly. Relative to linguistic processes, contemporary theories of subcortical participation in language have endorsed a role for the globus pallidus internus (GPi) in the control of lexical-semantic operations. However, attempts to empirically validate these postulates have been largely limited to neuropsychological investigations of verbal fluency abilities subsequent to pallidotomy. We evaluated the impact of bilateral posteroventral pallidotomy (BPVP) on language function across a range of general and high-level linguistic abilities, and validated/extended working theories of pallidal participation in language. Comprehensive linguistic profiles were compiled up to 1 month before and 3 months after BPVP in 6 subjects with Parkinson's disease (PD). Commensurate linguistic profiles were also gathered over a 3-month period for a nonsurgical control cohort of 16 subjects with PD and a group of 16 non-neurologically impaired controls (NC). Nonparametric between-groups comparisons were conducted and reliable change indices calculated, relative to baseline/3-month follow-up difference scores. Group-wise statistical comparisons between the three groups failed to reveal significant postoperative changes in language performance. Case-by-case data analysis relative to clinically consequential change indices revealed reliable alterations in performance across several language variables as a consequence of BPVP. These findings lend support to models of subcortical participation in language, which promote a role for the GPi in lexical-semantic manipulation mechanisms. Concomitant improvements and decrements in postoperative performance were interpreted within the context of additive and subtractive

  8. The Characteristics, Roles and Functions of Institutional Research Professionals in the Southern Association for Institutional Research.

    ERIC Educational Resources Information Center

    Harrington, Charles; Chen, HongYu

    A study was done on the variation in characteristics, roles, and functions of institutional research professionals affiliated with the Southern Association for Institutional Research (SAIR). The study examined professional role identity, location of offices in the organizational hierarchy, breadth of institutional research activities undertaken,…

  9. The Role of Functional and Perceptual Attributes: Evidence from Picture Naming in Dementia

    ERIC Educational Resources Information Center

    Harley, Trevor A.; Grant, Fiona

    2004-01-01

    We examined the performance of a group of people with moderately severe Alzheimer's type dementia on a naming task. We found that functional information plays an important role in determining naming performance on both living and non-living things. Perceptual information may play some role in naming living things. We also found some evidence that…

  10. Middle School Principals' Perceptions of Middle School Counselors' Roles and Functions

    ERIC Educational Resources Information Center

    Zalaquett, Carlos P.; Chatters, Seriashia J.

    2012-01-01

    The findings of this study expand current knowledge regarding principals' perceptions of school counselors. School principals play a key role in school counselors hiring or dismissal, and their perceptions of school counselors' roles and functions may influence their decisions. Reflecting on their views may also assist school principals in…

  11. Role of additional PCBM layer between ZnO and photoactive layers in inverted bulk-heterojunction solar cells

    PubMed Central

    Cho, Shinuk; Kim, Kwang-Dae; Heo, Jinhee; Lee, Joo Yul; Cha, Gihoon; Seo, Bo Yeol; Kim, Young Dok; Kim, Yong Soo; Choi, Si-young; Lim, Dong Chan

    2014-01-01

    In order to induce greater light absorption, nano-patterning is often applied to the metal-oxide buffer layer in inverted bulk-heterojunction(BHJ) solar cells. However, current homogeneity was significantly disturbed at the interface, leading to an efficiency that was not fully optimized. In this work, an additional PC61BM layer was inserted between the ZnO ripple and the photoactive layer to enhance the electron extraction. The insertion of additional PC61BM layer provided substantial advantages in the operation of inverted BHJ solar cells; specifically, it enhanced current homogeneity and lowered accumulation and trapping of photogenerated charges at the ZnO interface. Inclusion of the additional PC61BM layer led to effective quenching of electron–hole recombination by a reduction in the number of accumulated charges at the surface of ZnO ripples. This resulted in a 16% increase in the efficiency of inverted BHJ solar cells to 7.7%, compared to solar cells without the additional PC61BM layer. PMID:24603531

  12. Re(de)fining the Orthographic Neighborhood: The Role of Addition and Deletion Neighbors in Lexical Decision and Reading

    ERIC Educational Resources Information Center

    Davis, Colin J.; Perea, Manuel; Acha, Joana

    2009-01-01

    The influence of addition and deletion neighbors on visual word identification was investigated in four experiments. Experiments 1 and 2 used Spanish stimuli. In Experiment 1, lexical decision latencies were slower and less accurate for words and nonwords with higher-frequency deletion neighbors (e.g., "jugar" in "juzgar"), relative to control…

  13. Role of the addition of cabergoline to the management of acromegalic patients resistant to longterm treatment with octreotide LAR.

    PubMed

    Vilar, Lucio; Azevedo, Monalisa F; Naves, Luciana Ansaneli; Casulari, Luiz Augusto; Albuquerque, José Luciano; Montenegro, Renan M; Montenegro, Renan M; Figueiredo, Patricia; Nascimento, Gilvan C; Faria, Manuel S

    2011-06-01

    The aim of this prospective open trial was to evaluate the efficacy in normalizing IGF-I levels of the addition of cabergoline to the treatment of acromegalic patients partially responsive to Octreotide-LAR (OCT-LAR), a long acting somatotastin analog (SSA). Fifty-two patients who did not achieve hormonal control after longterm therapy (at least, 12 months) with OCT-LAR (30 mg every 28 days intramuscularly) were given cabergoline in addition to the SSA treatment. Normalization of IGF-I levels was achieved in 40.4% of patients by 6 months after the addition of cabergoline (1.0-3.0 mg/week; mean, 2.19 ± 0.64), and these patients were considered responsive. Compared to non-responsive subjects, responsive patients had significantly lower mean %ULNR-IGF-I and GH levels. However, the rate of hyperprolactinemia and positive immunohistochemical staining for PRL was similar in both groups, before the addition of cabergoline. Responsive patients were followed for at least 12 months on combination treatment and persisted with normal IGF-I levels. Patients with baseline %ULNR IGF-I up to 220% and/or GH up to 5 ng/ml were those who benefited the most from combination treatment. No patients with %ULNR-IGF-I>250% reached normalization of IGF-I levels. Our findings demonstrated that the addition of cabergoline, even at relatively low doses, is effective in both short- and long-term control of IGF-I levels in acromegalic patients partially responsive to octreotide LAR, particularly in those with mild/moderately elevated GH/IGF-levels, irrespective of prolactin status. PMID:21104199

  14. A general method for determining the functional role of a muscle.

    PubMed

    Andrews, J G

    1985-11-01

    This paper presents a general classification method for determining the functional role of any muscle, and a procedure for determining the sensitivity of that role to small changes in system parameters. The classification method is based on the premise that the system model, when acted upon solely by the muscle of interest, will depart from any initial rest configuration in such a way as to decrease the muscle's length. This method is particularly useful for multiple-joint muscles, and is illustrated by examining a slider-crank mechanism and straight line muscle model to determine the functional role of the hamstrings during a constrained leg flexion motion. PMID:4079362

  15. Structural and functional analysis of Rv0554 from Mycobacterium tuberculosis: testing a putative role in menaquinone biosynthesis.

    PubMed

    Johnston, Jodie M; Jiang, Ming; Guo, Zhihong; Baker, Edward N

    2010-08-01

    Mycobacterium tuberculosis, the cause of tuberculosis, is a devastating human pathogen against which new drugs are urgently needed. Enzymes from the biosynthetic pathway for menaquinone are considered to be valid drug targets. The protein encoded by the open reading frame Rv0554 has been expressed, purified and subjected to structural and functional analysis to test for a putative role in menaquinone biosynthesis. The crystal structure of Rv0554 has been solved and refined in two different space groups at 2.35 and 1.9 A resolution. The protein is dimeric, with an alpha/beta-hydrolase monomer fold. In each monomer, a large cavity adjacent to the catalytic triad is enclosed by a helical lid. Dimerization is mediated by the lid regions. Small-molecule additives used in crystallization bind in the active site, but no binding of ligands related to menaquinone biosynthesis could be detected and functional assays failed to support possible roles in menaquinone biosynthesis. PMID:20693690

  16. The Role of Family Functioning in the Stress Process of Dementia Caregivers: A Structural Family Framework

    ERIC Educational Resources Information Center

    Mitrani, Victoria B.; Lewis, John E.; Feaster, Daniel J.; Czaja, Sara J.; Eisdorfer, Carl; Schulz, Richard; Szapocznik, Jose

    2006-01-01

    Purpose: The purpose of the study was to evaluate the role of family functioning in the stress process in a sample of caregivers of dementia patients by using a structural family framework. The stress-process model of caregiver distress included family functioning as an intervening variable in the relationship between objective burden and…

  17. Counselors' Self-Analysis of Their Training as Related to Their Counselor Role and Functions.

    ERIC Educational Resources Information Center

    Frick, Donald L.

    This study was conducted to gain information from and about public school counselors concerning the relationship between their role and function and the nature of their counselor preparation training. It was also intended to determine the changes in training and counselor function necessary to provide for more adequate vocational counseling for…

  18. Intestinal Alkaline Phosphatase: Potential Roles in Promoting Gut Health in Weanling Piglets and Its Modulation by Feed Additives — A Review

    PubMed Central

    Melo, A. D. B.; Silveira, H.; Luciano, F. B.; Andrade, C.; Costa, L. B.; Rostagno, M. H.

    2016-01-01

    The intestinal environment plays a critical role in maintaining swine health. Many factors such as diet, microbiota, and host intestinal immune response influence the intestinal environment. Intestinal alkaline phosphatase (IAP) is an important apical brush border enzyme that is influenced by these factors. IAP dephosphorylates bacterial lipopolysaccharides (LPS), unmethylated cytosine-guanosine dinucleotides, and flagellin, reducing bacterial toxicity and consequently regulating toll-like receptors (TLRs) activation and inflammation. It also desphosphorylates extracellular nucleotides such as uridine diphosphate and adenosine triphosphate, consequently reducing inflammation, modulating, and preserving the homeostasis of the intestinal microbiota. The apical localization of IAP on the epithelial surface reveals its role on LPS (from luminal bacteria) detoxification. As the expression of IAP is reported to be downregulated in piglets at weaning, LPS from commensal and pathogenic gram-negative bacteria could increase inflammatory processes by TLR-4 activation, increasing diarrhea events during this phase. Although some studies had reported potential IAP roles to promote gut health, investigations about exogenous IAP effects or feed additives modulating IAP expression and activity yet are necessary. However, we discussed in this paper that the critical assessment reported can suggest that exogenous IAP or feed additives that could increase its expression could show beneficial effects to reduce diarrhea events during the post weaning phase. Therefore, the main goals of this review are to discuss IAP’s role in intestinal inflammatory processes and present feed additives used as growth promoters that may modulate IAP expression and activity to promote gut health in piglets. PMID:26732323

  19. Self-Conscious emotions’ role in functional outcomes within clinical populations

    PubMed Central

    Macaulay, Rebecca; Cohen, Alex

    2014-01-01

    Patients with severe mental illnesses (SMI) often experience dysfunction in their ability to efficiently carry out everyday roles and/or skills. These deficits are seen across many domains of daily functioning. We suggest that the “self-conscious emotions” of pride and shame play a role in these functional outcomes. Pride and shame appear to facilitate individuals’ ability to evaluate their group status, detect social threats, and to adjust their behaviors accordingly. This study utilized an objective performance measure of functional capacity and a self-report of quality of life (QoL) to examine the respective roles of pride and shame in functional outcomes within two SMI patient groups (schizophrenia and affective disorder) and a community control group. The influence of neurocognition, affect and symptomatology on functional outcomes was also assessed. The patient groups did not differ in cognitive functioning, QoL, or shame. The schizophrenia group reported significantly higher pride and displayed worse objective performance than the other groups. Within each of the groups, shame had an inverse relationship with QoL, while pride positively associated with QoL. Shame associated with worse functional capacity in the schizophrenia group. Shame associated with better functional capacity, while pride associated with worse functional capacity within the affective disorder group. PMID:24508025

  20. An essential role for DYF-11/MIP-T3 in assembling functional intraflagellar transport complexes.

    PubMed

    Li, Chunmei; Inglis, Peter N; Leitch, Carmen C; Efimenko, Evgeni; Zaghloul, Norann A; Mok, Calvin A; Davis, Erica E; Bialas, Nathan J; Healey, Michael P; Héon, Elise; Zhen, Mei; Swoboda, Peter; Katsanis, Nicholas; Leroux, Michel R

    2008-03-01

    MIP-T3 is a human protein found previously to associate with microtubules and the kinesin-interacting neuronal protein DISC1 (Disrupted-in-Schizophrenia 1), but whose cellular function(s) remains unknown. Here we demonstrate that the C. elegans MIP-T3 ortholog DYF-11 is an intraflagellar transport (IFT) protein that plays a critical role in assembling functional kinesin motor-IFT particle complexes. We have cloned a loss of function dyf-11 mutant in which several key components of the IFT machinery, including Kinesin-II, as well as IFT subcomplex A and B proteins, fail to enter ciliary axonemes and/or mislocalize, resulting in compromised ciliary structures and sensory functions, and abnormal lipid accumulation. Analyses in different mutant backgrounds further suggest that DYF-11 functions as a novel component of IFT subcomplex B. Consistent with an evolutionarily conserved cilia-associated role, mammalian MIP-T3 localizes to basal bodies and cilia, and zebrafish mipt3 functions synergistically with the Bardet-Biedl syndrome protein Bbs4 to ensure proper gastrulation, a key cilium- and basal body-dependent developmental process. Our findings therefore implicate MIP-T3 in a previously unknown but critical role in cilium biogenesis and further highlight the emerging role of this organelle in vertebrate development. PMID:18369462

  1. Synthetic metallic dialkydithiocarbamates as antiwear and extreme-pressure additives for lubricating oils: Role of metal on their effectiveness

    SciTech Connect

    Tuli, D.K.; Sarin, R.; Gupta, A.K.

    1995-04-01

    Dialkydithiocarbamates of five metals have been synthesized in pure form by following a simple general method. The alkyl chain in each of these compounds has been kept the same so as to observe the performance variations due to metal ions. The EP properties expressed as load wear index and weld load indicated the highest performance by Bi followed by Pb, Sb, Zn and Mo. The antiwear properties in terms of wear scar diameter, relative anti-wear effectiveness and mean average wear scar diameter show a performance order of Bi > Pb > Sb > Zn > Mo. The large ionic radius metals (Bi, Pb & Sb) had the best overall load-carrying performance and their effectiveness increased substantially when the additive concentration was more than 0.004 gm atom/Kg. The results suggest that Bi has good potential to replace toxic Pb and Sb from existing lubrication systems. 18 refs., 7 refs., 1 tab.

  2. Catalytic addition methods for the synthesis of functionalized diazoacetoacetates and application to the construction of highly substituted cyclobutanones.

    PubMed

    Doyle, Michael P; Kundu, Kousik; Russell, Albert E

    2005-11-10

    [reaction: see text] Methyl 3-(trialkylsilanyloxy)-2-diazo-3-butenoate undergoes Lewis acid-catalyzed Mukaiyama aldol addition with aromatic and aliphatic aldehydes in the presence of low catalytic amounts of Lewis acids in nearly quantitative yields. Scandium(III) triflate is the preferred catalyst and, notably, addition proceeds without decomposition of the diazo moiety. Diazoacetoacetate products from reactions with aromatic aldehydes undergo rhodium(II)-catalyzed ring closure to cyclobutanones with high diastereocontrol. Examples of complimentary Mannich-type addition reactions with imines are reported. PMID:16268530

  3. Indigenous perception and characterization of Yanyanku and Ikpiru: two functional additives for the fermentation of African locust bean.

    PubMed

    Agbobatinkpo, Pélagie B; Azokpota, Paulin; Akissoe, Noël; Kayodé, Polycarpe; Da Gbadji, Rachelle; Hounhouigan, D Joseph

    2011-01-01

    Indigenous perception, processing methods, and physicochemical and microbiological characteristics of Yanyanku and Ikpiru, two additives used to produce fermented African locust bean condiments, Sonru and Iru, were evaluated. According to producers, these additives accelerate the fermentation and soften the texture of the condiments. Yanyanku is produced by spontaneous fermentation with either Hibiscus sabdariffa or Gossypium hirsutum or Adansonia digitata seeds, whereas only Hibiscus sabdariffa seeds are used for Ikpiru. Both additives, with pH values ranging between 6.2 and 10 and Bacillus spores varying between 5.5 and 8.9 Log(10) (CFU/g), could be considered as softening additives or enrichment inocula to produce condiments. PMID:21888591

  4. A Genome-Wide Functional Investigation into the Roles of Receptor-Like Proteins in Arabidopsis1[W][OA

    PubMed Central

    Wang, Guodong; Ellendorff, Ursula; Kemp, Ben; Mansfield, John W.; Forsyth, Alec; Mitchell, Kathy; Bastas, Kubilay; Liu, Chun-Ming; Woods-Tör, Alison; Zipfel, Cyril; de Wit, Pierre J.G.M.; Jones, Jonathan D.G.; Tör, Mahmut; Thomma, Bart P.H.J.

    2008-01-01

    Receptor-like proteins (RLPs) are cell surface receptors that typically consist of an extracellular leucine-rich repeat domain, a transmembrane domain, and a short cytoplasmatic tail. In several plant species, RLPs have been found to play a role in disease resistance, such as the tomato (Solanum lycopersicum) Cf and Ve proteins and the apple (Malus domestica) HcrVf2 protein that mediate resistance against the fungal pathogens Cladosporium fulvum, Verticillium spp., and Venturia inaequalis, respectively. In addition, RLPs play a role in plant development; Arabidopsis (Arabidopsis thaliana) TOO MANY MOUTHS (TMM) regulates stomatal distribution, while Arabidopsis CLAVATA2 (CLV2) and its functional maize (Zea mays) ortholog FASCINATED EAR2 regulate meristem maintenance. In total, 57 RLP genes have been identified in the Arabidopsis genome and a genome-wide collection of T-DNA insertion lines was assembled. This collection was functionally analyzed with respect to plant growth and development and sensitivity to various stress responses, including susceptibility toward pathogens. A number of novel developmental phenotypes were revealed for our CLV2 and TMM insertion mutants. In addition, one AtRLP gene was found to mediate abscisic acid sensitivity and another AtRLP gene was found to influence nonhost resistance toward Pseudomonas syringae pv phaseolicola. This genome-wide collection of Arabidopsis RLP gene T-DNA insertion mutants provides a tool for future investigations into the biological roles of RLPs. PMID:18434605

  5. Prenatal Alcohol Exposure, Adaptive Function, and Entry into Adult Roles in a Prospective Study of Young Adults

    PubMed Central

    Lynch, Mary Ellen; Kable, Julie A.; Coles, Claire D.

    2015-01-01

    Introduction Although many studies have demonstrated effects of prenatal alcohol exposure (PAE) on physical, cognitive, and behavioral development in children, few have focused on the long term effects on adults. In this study, data are presented on adaptive function and entry into adult roles in a community sample of young adults with PAE. The expectation was that prenatally exposed adults would show lower adaptive functioning and more difficulty with entry into adult roles than the non-exposed control group and that these effects would be related to the severity of PAE effects. Method The predominantly African-American, low income sample included adults with a wide range of prenatal exposure (n = 123) as well as control groups for socioeconomic (SES) (n = 59) and disability (n = 54) status. The mothers of the alcohol-exposed and SES-control group participants were recruited before birth and offspring have been followed up periodically. The disability control group was recruited in adolescence. The adults were interviewed about adaptive function in day-to-day life and adult role entry. Collateral adults who were well-acquainted with each participant were interviewed concerning adaptive function. Results Results showed that adults who were dysmorphic and/or cognitively affected by PAE had difficulty with adaptive function and entry into adult roles. Males showing cognitive effects with no physical effects were the most severely affected. Results for exposed adults not showing physical or cognitive effects were similar to or more positive than those of the control group for most outcomes. Conclusion PAE has long-term effects on adaptive outcomes in early adulthood. Additional research should focus on possible interventions at this transition and on factors contributing to the adjustment of the exposed, but unaffected participants. PMID:26247662

  6. Diastereoselective Additive Trifluoromethylation/Halogenation of Isoxazole Triflones: Synthesis of All-Carbon-Functionalized Trifluoromethyl Isoxazoline Triflones

    PubMed Central

    Kawai, Hiroyuki; Sugita, Yutaka; Tokunaga, Etsuko; Sato, Hiroyasu; Shiro, Motoo; Shibata, Norio

    2014-01-01

    Highly functionalized 5-trifluoromethyl-2-isoxazoline derivatives featuring a triflyl (SO2CF3) group at the 4-position were successfully synthesized via diastereoselective trifluoromethylation and halogenation of isoxazole triflones using the Ruppert– Prakash reagent. The trifluoromethylation is quite general in terms of the substrates including 3,5-diaryl isoxazole triflones and 3-aryl-5-styrylisoxazole triflones to provide products in high yields with excellent diastereoselectivities. The highly functionalized 5-trifluoromethyl-2-isoxazoline derivatives are expected to be a new class of antiparasiticides. Thus the triflyl group both activates isoxazoles and the 4-postion of CF3 adducts, and has a potential biological function. PMID:24688889

  7. Family Functioning and Adolescent Psychological Maladjustment: The Mediating Role of Coping Strategies.

    PubMed

    Francisco, Rita; Loios, Sara; Pedro, Marta

    2016-10-01

    This study aims to analyze the mediating role of coping strategies in the relationship between family functioning and youth maladjustment. A community sample of 341 adolescents (M = 15.11 years old; SD = 1.71) completed self-report measures about such variables. Results showed that a perception of an inadequate family functioning was associated with the use of maladaptive coping strategies, as well as with youth psychological maladjustment. The results also revealed that rumination and support-seeking mediated the relationship between family functioning and internalizing behavior, and hostile expression of feelings played a mediating role between family functioning and externalizing behavior. No gender differences were found in the relationship between variables. This study emphasizes the importance of coping strategies used by adolescents to understand the relationship between family functioning and youth psychological maladjustment. PMID:26615594

  8. Plasmon excitation in metal slab by fast point charge: The role of additional boundary conditions in quantum hydrodynamic model

    SciTech Connect

    Zhang, Ying-Ying; An, Sheng-Bai; Song, Yuan-Hong Wang, You-Nian; Kang, Naijing; Mišković, Z. L.

    2014-10-15

    We study the wake effect in the induced potential and the stopping power due to plasmon excitation in a metal slab by a point charge moving inside the slab. Nonlocal effects in the response of the electron gas in the metal are described by a quantum hydrodynamic model, where the equation of electronic motion contains both a quantum pressure term and a gradient correction from the Bohm quantum potential, resulting in a fourth-order differential equation for the perturbed electron density. Thus, besides using the condition that the normal component of the electron velocity should vanish at the impenetrable boundary of the metal, a consistent inclusion of the gradient correction is shown to introduce two possibilities for an additional boundary condition for the perturbed electron density. We show that using two different sets of boundary conditions only gives rise to differences in the wake potential at large distances behind the charged particle. On the other hand, the gradient correction in the quantum hydrodynamic model is seen to cause a reduction in the depth of the potential well closest to the particle, and a reduction of its stopping power. Even for a particle moving in the center of the slab, we observe nonlocal effects in the induced potential and the stopping power due to reduction of the slab thickness, which arise from the gradient correction in the quantum hydrodynamic model.

  9. A dominant role of oxygen additive on cold atmospheric-pressure He + O{sub 2} plasmas

    SciTech Connect

    Yang, Aijun; Liu, Dingxin E-mail: xhw@mail.xjtu.edu.cn; Rong, Mingzhe; Wang, Xiaohua E-mail: xhw@mail.xjtu.edu.cn; Kong, Michael G.

    2014-08-15

    We present in this paper how oxygen additive impacts on the cold atmospheric-pressure helium plasmas by means of a one-dimensional fluid model. For the oxygen concentration [O{sub 2}] > ∼0.1%, the influence of oxygen on the electron characteristics and the power dissipation becomes important, e.g., the electron density, the electron temperature in sheath, the electron-coupling power, and the sheath width decreasing by 1.6 to 16 folds with a two-log increase in [O{sub 2}] from 0.1% to 10%. Also the discharge mode evolves from the γ mode to the α mode. The reactive oxygen species are found to peak in the narrow range of [O{sub 2}] = 0.4%–0.9% in the plasmas, similar to their power-coupling values. This applies to their wall fluxes except for those of O* and O{sub 2}{sup −}. These two species have very short lifetimes, thus only when generated in boundary layers within several micrometers next to the electrode can contribute to the fluxes. The dominant reactive oxygen species and the corresponding main reactions are schematically presented, and their relations are quantified for selected applications.

  10. Role of Cu additive on the dielectric relaxation of Se75Te25 and Se85Te15 glassy alloys

    NASA Astrophysics Data System (ADS)

    Sharma, J.; Kumar, S.

    2010-07-01

    The effect of Cu additive on the dielectric relaxation of two binary Se-Te glassy systems, comparing the properties of a-Se75Te25, a-Se85Te15 and a-Se75Te15Cu10 alloys has been reported. The temperature and frequency dependence of dielectric parameters in Glassy Se75Te25, Se85Te15 and Se75Te15Cu10 alloys are studied by measuring capacitance and dissipation factor in the frequency range (1 kHz-5 MHz) and temperature range (300-350 K). A Debye like relaxation of dielectric behavior has been observed. A comprehensive study on the relaxation mechanism revealed that the presence of grains and grain boundaries across the pallet thickness is the basic relaxation process. A detailed analysis shows that the observed dielectric loss is in agreement with the Guintini's theory of dielectric dispersion based on two electron hopping over a potential barrier and is applicable in the present case. Dielectric constant (ɛ’), dielectric loss (ɛ”), loss tangent (δ) and capacitive reactance (Xc) are found highly frequency and temperature dependent. Dependence of these dielectric parameters over the metallic impurity Cu, has also been found in the present glassy system and has been discussed in terms of electronegativity difference between the elements used in making the aforesaid glassy system.

  11. Crystallization of the Membrane-Associated Annexin B1: Roles of Additive Screen, Dynamic Light Scattering, and Bioactivity Assay

    SciTech Connect

    Ding, F.; Xu, Y; Azzi, A; Zhu, D; Rehse, D; Chen, C; Sun, S; Lin, S

    2010-01-01

    Annexin B1 (AnxB1) is a calcium-dependent phospholipid binding protein from Taenia solium cysticercus and has been reported to possess anticoagulant activity, to inhibit phospholipase A{sub 2}, and to regulate membrane transport. Native AnxB1 and its selenomethionyl derivative have been overproduced in Escherichia coli and purified. The results of dynamic light scattering analysis showed that Hepes buffer combined with low concentration salts (NaCl or CaCl{sub 2}) was beneficial for preventing aggregation and for AnxB1 stabilization in the storage. After the additive screen, crystals have been yielded in the presence of guanidine hydrochloride (Gn-HCl). We determined that a low concentration of Gn-HCl significantly delayed clotting time and increased anticoagulant activity. Analysis of the crystal showed that in the presence of Gn-HCl, AnxB1 crystallizes in orthorhombic space group, which is modified from the cubic space group for crystals grown in the absence of Gn-HCl. A high quality data set (at 1.9 {angstrom}) has been collected successfully for crystals of L-selenomethionine labeled protein in the presence of Gn-HCl, to solve the structure with the single anomalous dispersion method (SAD). The unit cell parameters are a = 102.35 {angstrom}, b = 103.59 {angstrom}, c = 114.60 {angstrom}, {alpha} = {beta} = {gamma} = 90.00{sup o}.

  12. The ventral pallidum: Subregion-specific functional anatomy and roles in motivated behaviors

    PubMed Central

    Root, David H.; Melendez, Roberto I.; Zaborszky, Laszlo; Napier, T. Celeste

    2015-01-01

    The ventral pallidum (VP) plays a critical role in the processing and execution of motivated behaviors. Yet this brain region is often overlooked in published discussions of the neurobiology of mental health (e.g., addiction, depression). This contributes to a gap in understanding the neurobiological mechanisms of psychiatric disorders. This review is presented to help bridge the gap by providing a resource for current knowledge of VP anatomy, projection patterns and subregional circuits, and how this organization relates to the function of VP neurons and ultimately behavior. For example, ventromedial (VPvm) and dorsolateral (VPdl) VP subregions receive projections from nucleus accumbens shell and core, respectively. Inhibitory GABAergic neurons of the VPvm project to mediodorsal thalamus, lateral hypothalamus, and ventral tegmental area, and this VP subregion helps discriminate the appropriate conditions to acquire natural rewards or drugs of abuse, consume preferred foods, and perform working memory tasks. GABAergic neurons of the VPdl project to subthalamic nucleus and substantia nigra pars reticulata, and this VP subregion is modulated by, and is necessary for, drug-seeking behavior. Additional circuits arise from nonGABAergic neuronal phenotypes that are likely to excite rather than inhibit their targets. These subregional and neuronal phenotypic circuits place the VP in a unique position to process motivationally-relevant stimuli and coherent adaptive behaviors. PMID:25857550

  13. Role of cellular prion proteins in the function of macrophages and dendritic cells.

    PubMed

    Nitta, Kayako; Sakudo, Akikazu; Masuyama, Jun; Xue, Guangai; Sugiura, Katsuaki; Onodera, Takashi

    2009-01-01

    The cellular isoform of prion proteins (PrPC) is expressed in hematopoietic stem cells, granulocytes, T and B lymphocyte natural killer cells, platelets, monocytes, dendritic cells, and follicular dendritic cells, which may act as carrier cells for the spread of its abnormal isoform (PrPSc) before manifesting transmissible spongiform encephalopathies (TSEs). In particular, macrophages and dendritic cells seem to be involved in the replication of PrPSc after ingestion. In addition, information on the role of PrPC during phagocytotic activity in these cells has been obtained. A recent study showed that resident macrophages from ZrchI PrP gene (Prnp)-deficient (Prnp-/-) mice show augmented phagocytotic activity compared to Prnp+/+ counterparts. In contrast, our study suggests that Rikn Prnp-/- peritoneal macrophages show pseudopodium extension arrest and up-regulation of phagocytotic activity compared to Prnp+/+ cells. Although reports regarding phagocytotic activity in resident and peritoneal macrophages are inconsistent between ZrchI and Rikn Prnp-/- mice, it seems plausible that PrPC in macrophages could contribute to maintain the immunological environment. This review will introduce the recent progress in understanding the functions of PrPC in macrophages and dendritic cells under physiological conditions and its involvement in the pathogenesis of prion diseases. PMID:19275736

  14. Biogeochemical hotspots within forested landscapes: quantifying the functional role of vernal pools in ecosystem processes

    NASA Astrophysics Data System (ADS)

    Capps, K. A.; Rancatti, R.; Calhoun, A.; Hunter, M.

    2013-12-01

    Biogeochemical hotspots are characterized as small areas within a landscape matrix that show comparably high chemical reaction rates relative to surrounding areas. For small, natural features to generate biogeochemical hotspots within a landscape, their contribution to nutrient dynamics must be significant relative to nutrient demand of the surrounding landscape. In northeastern forests in the US, vernal pools are abundant, small features that typically fill in spring with snow melt and precipitation and dry by the end of the summer. Ephemeral flooding alters soil moisture and the depth of the oxic/anoxic boundary in the soil, which may affect leaf-litter decomposition rates and nutrient dynamics including denitrification. Additionally, pool-breeding organisms may influence nutrient dynamics via consumer-driven nutrient remineralization. We studied the effects of vernal pools on rates of leaf-litter decomposition and denitrification in forested habitats in Maine. Our results indicate leaf-litter decomposition and denitrification rates in submerged habitats of vernal pools were greater than in upland forest habitat. Our data also suggest pool-breeding organisms, such as wood frogs, may play an important role in nutrient dynamics within vernal pools. Together, the results suggest vernal pools may function as biogeochemical hotspots within forested landscapes.

  15. The ventral pallidum: Subregion-specific functional anatomy and roles in motivated behaviors.

    PubMed

    Root, David H; Melendez, Roberto I; Zaborszky, Laszlo; Napier, T Celeste

    2015-07-01

    The ventral pallidum (VP) plays a critical role in the processing and execution of motivated behaviors. Yet this brain region is often overlooked in published discussions of the neurobiology of mental health (e.g., addiction, depression). This contributes to a gap in understanding the neurobiological mechanisms of psychiatric disorders. This review is presented to help bridge the gap by providing a resource for current knowledge of VP anatomy, projection patterns and subregional circuits, and how this organization relates to the function of VP neurons and ultimately behavior. For example, ventromedial (VPvm) and dorsolateral (VPdl) VP subregions receive projections from nucleus accumbens shell and core, respectively. Inhibitory GABAergic neurons of the VPvm project to mediodorsal thalamus, lateral hypothalamus, and ventral tegmental area, and this VP subregion helps discriminate the appropriate conditions to acquire natural rewards or drugs of abuse, consume preferred foods, and perform working memory tasks. GABAergic neurons of the VPdl project to subthalamic nucleus and substantia nigra pars reticulata, and this VP subregion is modulated by, and is necessary for, drug-seeking behavior. Additional circuits arise from nonGABAergic neuronal phenotypes that are likely to excite rather than inhibit their targets. These subregional and neuronal phenotypic circuits place the VP in a unique position to process motivationally relevant stimuli and coherent adaptive behaviors. PMID:25857550

  16. Role of IGF-1 in cortical plasticity and functional deficit induced by sensorimotor restriction.

    PubMed

    Mysoet, Julien; Dupont, Erwan; Bastide, Bruno; Canu, Marie-Hélène

    2015-09-01

    In the adult rat, sensorimotor restriction by hindlimb unloading (HU) is known to induce impairments in motor behavior as well as a disorganization of somatosensory cortex (shrinkage of the cortical representation of the hindpaw, enlargement of the cutaneous receptive fields, decreased cutaneous sensibility threshold). Recently, our team has demonstrated that IGF-1 level was decreased in the somatosensory cortex of rats submitted to a 14-day period of HU. To determine whether IGF-1 is involved in these plastic mechanisms, a chronic cortical infusion of this substance was performed by means of osmotic minipump. When administered in control rats, IGF-1 affects the size of receptive fields and the cutaneous threshold, but has no effect on the somatotopic map. In addition, when injected during the whole HU period, IGF-1 is interestingly implied in cortical changes due to hypoactivity: the shrinkage of somatotopic representation of hindlimb is prevented, whereas the enlargement of receptive fields is reduced. IGF-1 has no effect on the increase in neuronal response to peripheral stimulation. We also explored the functional consequences of IGF-1 level restoration on tactile sensory discrimination. In HU rats, the percentage of paw withdrawal after a light tactile stimulation was decreased, whereas it was similar to control level in HU-IGF-1 rats. Taken together, the data clearly indicate that IGF-1 plays a key-role in cortical plastic mechanisms and in behavioral alterations induced by a decrease in sensorimotor activity. PMID:25958232

  17. Rule-Based Category Learning in Children: The Role of Age and Executive Functioning

    PubMed Central

    Rabi, Rahel; Minda, John Paul

    2014-01-01

    Rule-based category learning was examined in 4–11 year-olds and adults. Participants were asked to learn a set of novel perceptual categories in a classification learning task. Categorization performance improved with age, with younger children showing the strongest rule-based deficit relative to older children and adults. Model-based analyses provided insight regarding the type of strategy being used to solve the categorization task, demonstrating that the use of the task appropriate strategy increased with age. When children and adults who identified the correct categorization rule were compared, the performance deficit was no longer evident. Executive functions were also measured. While both working memory and inhibitory control were related to rule-based categorization and improved with age, working memory specifically was found to marginally mediate the age-related improvements in categorization. When analyses focused only on the sample of children, results showed that working memory ability and inhibitory control were associated with categorization performance and strategy use. The current findings track changes in categorization performance across childhood, demonstrating at which points performance begins to mature and resemble that of adults. Additionally, findings highlight the potential role that working memory and inhibitory control may play in rule-based category learning. PMID:24489658

  18. Additional Shear Resistance from Fault Roughness and its Role in Determining Stress Levels on Mature and Immature Faults

    NASA Astrophysics Data System (ADS)

    Fang, Z.; Dunham, E. M.

    2011-12-01

    The majority of crustal faults host earthquakes at τ /(σ - p) ˜ 0.6 (τ is shear stress and (σ - p) is the effective normal stress), while mature plate-boundary faults, like the San Andreas Fault (SAF), host earthquakes at τ /(σ - p) ˜ 0.2. A leading explaination for the weakness of the SAF is the existence of dynamic weakening, which, on planar faults, allows self-sustaining rupture at a critical background stress level τ pulse/(σ - p) ˜ 0.25. Provided that dynamic weakening also occurs on less mature faults, which seems likely given the ubiquity of dynamic weakening in high velocity friction experiments, the stress levels on the less mature faults are puzzling. We offer a self-consistent explanation for the relatively high stress levels on immature faults that is compatible with dynamic weakening and low coseismic strength of all faults. Our explanation is that increased geometrical complexity of less mature faults introduces an additional resistance to slip that must be overcome in order for the fault to host ruptures. Lab and field observations suggest that faults are self-similar surfaces with amplitude-to-wavelength ratio α in the range of 10-3 (mature faults) to 10-2 (immature faults). Slip on such faults induces huge stress perturbations near the fault. Projection of these stress perturbations back onto the rough fault surface results in an additional shear resistance to slip, the 'roughness drag' τ drag, that exists even if the fault is frictionless. A perturbation analysis, accurate to second order in α , shows that τ drag = 8π 3 α 2[G/(1-&nu)][Δ u/λ min], in which G is shear modulus, ν is the Poisson's ratio, Δ u is the amount of slip, and λ min is the minimum wavelength of roughness. Estimates indicate that τ drag is negligible on mature faults (α ˜ 10-3) but can become substantial on immature faults (α ˜ 10-2). We expect that the finite strength of the off-fault material ultimately bounds τ drag to a value determined by the

  19. Improvement in antioxidant functionality and shelf life of yukwa (fried rice snack) by turmeric (Curcuma longa L.) powder addition.

    PubMed

    Lim, Seung-Taik; Han, Jung-Ah

    2016-05-15

    The physico-chemical, oxidative and sensory characteristics of fried rice snack, yukwa with different amounts of turmeric powder (Curcuma longa) were investigated. The moisture content of the pallet ranged from 16.47% to 19.84%. After frying the pallet, a slight decrease in the degree of expansion was obtained with increasing turmeric powder content. The textural properties of yukwa were not changed until the turmeric powder content reached 5%; however, over 8% addition induced a decrease in the hardness and an increase in the crispiness. Oxidative deterioration was effectively inhibited by turmeric powder addition, and more turmeric powder in yukwa led to higher free radical scavenging activity. Based on the sensory characteristics, a 5% addition of turmeric powder was the most acceptable for the yukwa product. In the correlation results among variables, the moisture content of the pallet proved to be the most important factor for yukwa quality. PMID:26776012

  20. Gender differences in the roles and functions of inpatient psychiatric nurses.

    PubMed

    Torkelson, Diane J; Seed, Mary S

    2011-03-01

    This study explored the difference between male and female psychiatric nurses' job performance and job satisfaction levels on an acute care inpatient unit. The amount of time male (n = 28) and female (n = 45) nurses spent on 10 specific functions and roles during a shift were observed and recorded. The nurses also self-rated the amount of time they spent on these specific functions and roles. The observed and self-rated functions were then correlated with job satisfaction. Female nurses were observed and self-rated as spending significantly more time on patient care activities, and these activities were significantly correlated with higher job satisfaction levels. Male nurses who self-rated spending more time on patient care activities had significantly lower job satisfaction scores. Findings confirm the concepts from social role theory that gender identity and expectations influence job performance in psychiatric nursing. The results offer insight for increasing job satisfaction and recruitment/retention efforts. PMID:21323265

  1. Roles, Functions, and Mechanisms of Long Non-coding RNAs in Cancer

    PubMed Central

    Fang, Yiwen; Fullwood, Melissa J.

    2016-01-01

    Long non-coding RNAs (lncRNAs) play important roles in cancer. They are involved in chromatin remodeling, as well as transcriptional and post-transcriptional regulation, through a variety of chromatin-based mechanisms and via cross-talk with other RNA species. lncRNAs can function as decoys, scaffolds, and enhancer RNAs. This review summarizes the characteristics of lncRNAs, including their roles, functions, and working mechanisms, describes methods for identifying and annotating lncRNAs, and discusses future opportunities for lncRNA-based therapies using antisense oligonucleotides. PMID:26883671

  2. Nickel superoxide dismutase: structural and functional roles of His1 and its H-bonding network

    SciTech Connect

    Maroney, Michael J.; Cabelli, Diane E.; Ryan, Kelly C.; Guce, Abigail I.; Johnson, Olivia E.; Brunold, Thomas C.; Garman, Scott C.

    2015-01-21

    Crystal structures of nickel-dependent superoxide dismutases (NiSODs) reveal the presence of a H-bonding network formed between the NH group of the apical imidazole ligand from His1 and the Glu17 carboxylate from a neighboring subunit in the hexameric enzyme. This interaction is supported by another intrasubunit H-bond between Glu17 and Arg47. In this study, four mutant NiSOD proteins were produced to experimentally evaluate the roles of this H-bonding network and compare the results with prior predictions from density functional theory calculations. The X-ray crystal structure of H1A-NiSOD, which lacks the apical ligand entirely, reveals that in the absence of the Glu17-His1 H-bond, the active site is disordered. Characterization of this variant using X-ray absorption spectroscopy (XAS) shows that Ni(II) is bound in the expected N₂S₂ planar coordination site. Despite these structural perturbations, the H1A-NiSOD variant retains 4% of wild-type (WT) NiSOD activity. Three other mutations were designed to preserve the apical imidazole ligand but perturb the H-bonding network: R47A-NiSOD, which lacks the intramolecular H-bonding interaction; E17R/R47A-NiSOD, which retains the intramolecular H-bond but lacks the intermolecular Glu17-His1 H-bond; and E17A/R47ANiSOD, which lacks both H-bonding interactions. These variants were characterized by a combination of techniques, including XAS to probe the nickel site structure, kinetic studies employing pulse-radiolytic production of superoxide, and electron paramagnetic resonance to assess the Ni redox activity. The results indicate that in addition to the roles in redox tuning suggested on the basis of previous computational studies, the Glu17-His1 H-bond plays an important structural role in the proper folding of the “Ni-hook” motif that is a critical feature of the active site.

  3. Nickel superoxide dismutase: structural and functional roles of His1 and its H-bonding network

    DOE PAGESBeta

    Maroney, Michael J.; Cabelli, Diane E.; Ryan, Kelly C.; Guce, Abigail I.; Johnson, Olivia E.; Brunold, Thomas C.; Garman, Scott C.

    2015-01-21

    Crystal structures of nickel-dependent superoxide dismutases (NiSODs) reveal the presence of a H-bonding network formed between the NH group of the apical imidazole ligand from His1 and the Glu17 carboxylate from a neighboring subunit in the hexameric enzyme. This interaction is supported by another intrasubunit H-bond between Glu17 and Arg47. In this study, four mutant NiSOD proteins were produced to experimentally evaluate the roles of this H-bonding network and compare the results with prior predictions from density functional theory calculations. The X-ray crystal structure of H1A-NiSOD, which lacks the apical ligand entirely, reveals that in the absence of the Glu17-His1more » H-bond, the active site is disordered. Characterization of this variant using X-ray absorption spectroscopy (XAS) shows that Ni(II) is bound in the expected N₂S₂ planar coordination site. Despite these structural perturbations, the H1A-NiSOD variant retains 4% of wild-type (WT) NiSOD activity. Three other mutations were designed to preserve the apical imidazole ligand but perturb the H-bonding network: R47A-NiSOD, which lacks the intramolecular H-bonding interaction; E17R/R47A-NiSOD, which retains the intramolecular H-bond but lacks the intermolecular Glu17-His1 H-bond; and E17A/R47ANiSOD, which lacks both H-bonding interactions. These variants were characterized by a combination of techniques, including XAS to probe the nickel site structure, kinetic studies employing pulse-radiolytic production of superoxide, and electron paramagnetic resonance to assess the Ni redox activity. The results indicate that in addition to the roles in redox tuning suggested on the basis of previous computational studies, the Glu17-His1 H-bond plays an important structural role in the proper folding of the “Ni-hook” motif that is a critical feature of the active site.« less

  4. Evidence for a functional vasodilatatory role for hydrogen sulphide in the human cutaneous microvasculature

    PubMed Central

    Kutz, Jessica L; Greaney, Jody L; Santhanam, Lakshmi; Alexander, Lacy M

    2015-01-01

    blood pressure in animal models; however, its specific mechanistic role in the human vasculature remains unclear. In the present study, we report the novel finding that the enzymes responsible for endogenous H2S production, cystathionine-γ-lyase and 3-mercaptopyruvate sulphurtransferase, are expressed in the human cutaneous circulation. Functionally, we show that H2S-induced cutaneous vasodilatation is mediated, in part, by tetraethylammonium-sensitive calcium-dependent potassium channels and not by ATP-sensitive potassium channels. In addition, nitric oxide and cyclo-oxygenase-derived byproducts are required for full expression of exogenous H2S-mediated cutaneous vasodilatation. Future investigations of the potential role for H2S with respect to modulating vascular function in humans may have important clinical implications for understanding the mechanisms underlying vascular dysfunction characteristic of multiple cardiovascular pathologies. PMID:25639684

  5. Positive Affect in the Midst of Distress: Implications for Role Functioning

    PubMed Central

    Moskowitz, Judith Tedlie; Shmueli-Blumberg, Dikla; Acree, Michael; Folkman, Susan

    2012-01-01

    Stress has been shown to deplete the self-regulation resources hypothesized to facilitate effective role functioning. However, recent research suggests that positive affect may help to replenish these vital self-regulation resources. Based on revised Stress and Coping theory and the Broaden-and-Build theory of positive emotion, three studies provide evidence of the potential adaptive function of positive affect in the performance of roles for participants experiencing stress. Participants were students (Study 1), caregivers of ill children (Study 2), and individuals recently diagnosed with HIV (Study 3). In cross sectional analyses, using role functioning as an indicator of self-regulation performance, we found that positive affect was significantly correlated with better self regulation performance, independent of the effects of negative affect. The effects were not as strong longitudinally, however, and there was little evidence of a reciprocal association between increases in positive affect and improvements in role functioning over time. The results provide some modest support for hypotheses stemming from the Broaden and Build model of positive emotion and revised Stress and Coping theory, both of which argue for unique adaptive functions of positive affect under stressful conditions. PMID:23175617

  6. The role of intestinal epithelial barrier function in the development of NEC

    PubMed Central

    Halpern, Melissa D; Denning, Patricia W

    2015-01-01

    The intestinal epithelial barrier plays an important role in maintaining host health. Breakdown of intestinal barrier function is known to play a role in many diseases such as infectious enteritis, idiopathic inflammatory bowel disease, and neonatal inflammatory bowel diseases. Recently, increasing research has demonstrated the importance of understanding how intestinal epithelial barrier function develops in the premature neonate in order to develop strategies to promote its maturation. Optimizing intestinal barrier function is thought to be key to preventing neonatal inflammatory bowel diseases such as necrotizing enterocolitis. In this review, we will first summarize the key components of the intestinal epithelial barrier, what is known about its development, and how this may explain NEC pathogenesis. Finally, we will review what therapeutic strategies may be used to promote optimal development of neonatal intestinal barrier function in order to reduce the incidence and severity of NEC. PMID:25927016

  7. The dual roles of functional groups in the photoluminescence of graphene quantum dots

    NASA Astrophysics Data System (ADS)

    Wang, Shujun; Cole, Ivan S.; Zhao, Dongyuan; Li, Qin

    2016-03-01

    The photoluminescent properties of graphene nanoparticle (named graphene quantum dots) have attracted significant research attention in recent years owing to their profound application potential. However, the photoluminescence (PL) origin of this class of nanocarbons is still unclear. In this paper, combining direct experimental evidence enabled by a facile size-tunable oxygenated graphene quantum dots (GQDs) synthesis method and theoretical calculations, the roles of the aromatic core, functional groups and disordered structures (i.e. defects and sp3 carbon) in the PL of oxygenated GQDs are elucidated in detail. In particular, we found that the functional groups on GQDs play dual roles in the overall emission: (1) they enable π* --> n and σ* --> n transitions, resulting in a molecular type of PL, spectrally invariable with change of particle size or excitation energy; (2) similar to defects and sp3 carbon, functional groups also induce structural deformation to the aromatic core, leading to mid-gap states or, in other words, energy traps, causing π* --> mid-gap states --> π transitions. Therefore, functional groups contribute to both the blue edge and the red shoulder of GQDs' PL spectra. The new insights on the role of functional groups in PL of fluorescent nanocarbons will enable better designs of this new class of materials.The photoluminescent properties of graphene nanoparticle (named graphene quantum dots) have attracted significant research attention in recent years owing to their profound application potential. However, the photoluminescence (PL) origin of this class of nanocarbons is still unclear. In this paper, combining direct experimental evidence enabled by a facile size-tunable oxygenated graphene quantum dots (GQDs) synthesis method and theoretical calculations, the roles of the aromatic core, functional groups and disordered structures (i.e. defects and sp3 carbon) in the PL of oxygenated GQDs are elucidated in detail. In particular, we found

  8. Bilingualism and the Development of Executive Function: The Role of Attention

    PubMed Central

    Bialystok, Ellen

    2015-01-01

    This paper reviews research examining the effect of bilingualism on children’s cognitive development, and in particular, executive function. Studies reporting bilingual advantages in various tasks are described with the purpose of identifying the process or executive function component that might be responsible for this bilingual advantage. Several possibilities are discussed, such as inhibitory control. Finally, the role of attention is proposed as a fundamental process that initiates developmental differences in bilingual children from as early as infancy. PMID:26019718

  9. Shyness and Vocabulary: The Roles of Executive Functioning and Home Environmental Stimulation

    PubMed Central

    Nayena Blankson, A.; O’Brien, Marion; Leerkes, Esther M.; Marcovitch, Stuart; Calkins, Susan D.

    2010-01-01

    Although shyness has often been found to be negatively related to vocabulary, few studies have examined the processes that produce or modify this relation. The present study examined executive functioning skills and home environmental stimulation as potential mediating and moderating mechanisms. A sample of 3.5-year-old children (N=254) were administered executive functioning tasks and a vocabulary test during a laboratory visit. Mothers completed questionnaires assessing child shyness and home environmental stimulation. Our primary hypothesis was that executive functioning mediates the association between shyness and vocabulary, and home environmental stimulation moderates the relation between executive functioning and vocabulary. Alternative hypotheses were also tested. Results indicated that children with better executive functioning skills developed stronger vocabularies when reared in more, versus less, stimulating environments. Implications of these results are discussed in terms of the role of shyness, executive functioning, and home environmental stimulation in early vocabulary development. PMID:22096267

  10. The Role of Vitamin D in Blood Pressure, Endothelial and Renal Function in Postmenopausal Women

    PubMed Central

    Liu, Zhao-Min; Woo, Jean; Wu, Sheng-Hui; Ho, Suzanne C.

    2013-01-01

    Background: Vitamin D is a pro-hormone that plays an essential role in the vasculature and in kidney function. Aims: To review the extra-skeletal effects of vitamin D on blood pressure, endothelial and renal function with emphasis on recent findings in postmenopausal women. Methods: Included in this review was a PubMed database search for English language articles through March 2013. This review discussed the physiology and definition of vitamin D deficiency, the recent evidence for the role vitamin D in blood pressure, vascular and renal function. Results: Experimental and epidemiological data suggest that vitamin D plays an important role in the vasculature and in kidney function. Low vitamin D concentrations appear to significantly associate with hypertension, endothelial and renal dysfunction. However, the results of clinical trials have generally been mixed. Studies specifically conducted among postmenopausal women are limited and findings are still inconsistent. Conclusions: Definitive studies are warranted to elucidate the effects of vitamin D supplementation on vascular and renal function and a more detailed work is needed to outline the route, duration and optimal dose of supplementation. It is premature to recommend vitamin D as a therapeutic option in the improvement of vascular and renal function at the current stage. PMID:23839167

  11. Structural-functional characterization of the cathodic haemoglobin of the conger eel Conger conger: molecular modelling study of an additional phosphate-binding site.

    PubMed Central

    Pellegrini, Mariagiuseppina; Giardina, Bruno; Verde, Cinzia; Carratore, Vito; Olianas, Alessandra; Sollai, Luigi; Sanna, Maria T; Castagnola, Massimo; di Prisco, Guido

    2003-01-01

    The protein sequence data for the alpha- and beta-chains have been deposited in the SWISS-PROT and TrEMBL protein knowledgebase under the accession numbers P83479 and P83478 respectively. The Conger conger (conger eel) haemoglobin (Hb) system is made of three components, one of which, the so-called cathodic Hb, representing approx. 20% of the total pigment, has been purified and characterized from both a structural and functional point of view. Stripped Hb showed a reverse Bohr effect, high oxygen affinity and slightly low cooperativity in the absence of any effector. Addition of saturating GTP strongly influences the pH dependence of the oxygen affinity, since the reverse Bohr effect, observed under stripped conditions, is converted into a small normal Bohr effect. A further investigation of the GTP effect on oxygen affinity, carried out by fitting its titration curve, demonstrated the presence of two independent binding sites. Therefore, on the basis of the amino acid sequence of the alpha- and beta-chains, which have been determined, a computer modelling study has been performed. The data suggest that C. conger cathodic Hb may bind organic phosphates at two distinct binding sites located along the central cavity of the tetramer by hydrogen bonds and/or electrostatic interactions with amino acid residues of both chains, which have been identified. Among these residues, the two Lys-alpha(G6) (where the letter refers to the haemoglobin helix and the number to the amino acid position in the helix) appear to have a key role in the GTP movement from the external binding region to the internal central cavity of the tetrameric molecule. PMID:12646043

  12. [CHAPERONES FUNCTION HSP60 AND HSP90 AND THEIR ROLE IN CARDIAC PATHOLOGY].

    PubMed

    Kazimirko, V K; Kutovoy, V V; Bobyk, V I; Kozak, I O; Ivanitskaya, L M; Dubkova, A G; Silanteva, T S

    2014-01-01

    In review provides information about the function oft the body of chaperones and their role in the development of pathological processes, including--atherosclerosis and coronary heart disease. Marked comminications systems chaperones to the immune and endocrine systems, and inflammation. PMID:26492771

  13. Early Childcare, Executive Functioning, and the Moderating Role of Early Stress Physiology

    ERIC Educational Resources Information Center

    Berry, Daniel; Willoughby, Michael T.; Blair, Clancy; Ursache, Alexandra; Granger, Douglas A.

    2014-01-01

    Intervention studies indicate that children's childcare experiences can be leveraged to support the development of executive functioning (EF). The role of more normative childcare experiences is less clear. Increasingly, theory and empirical work suggest that individual differences in children's physiological stress systems may be…

  14. Screening biochars for heavy metal retention in soil: role of oxygen functional groups

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oxygen-containing carboxyl, hydroxyl, and phenolic surface functional groups of soil organic and mineral components play central roles in binding metal ions, and biochar amendment can provide means of increasing these surface ligands in soil. In this study, positive matrix factorization (PMF) was f...

  15. The Effects of War on Children: School Psychologists' Role and Function

    ERIC Educational Resources Information Center

    Lasser, Jon; Adams, Krysta

    2007-01-01

    War may be the most profound psychosocial stressor on child and adolescent development, for it has the potential to inflict loss, disruption of stability, deleterious health effects and family/community system disorganization. This article reviews the literature regarding the effects of war on children and explores the role and function of the…

  16. Public Libraries and School Libraries, Their Roles and Functions; An Anthology of Opinions.

    ERIC Educational Resources Information Center

    Kitchner Public Library (Ontario).

    This anthology of opinions about the roles and functions of public and school libraries covers the following topics: (1) The School-Housed Public Library--An Evaluation; (2) School and Public Library Relationships; (3) The Case for Independent School Libraries; (4) Report on Killarney Branch Library (Vancouver); (5) Report on the Flint Public…

  17. The Role of the Verb in Grammatical Function Assignment in English and Korean

    ERIC Educational Resources Information Center

    Hwang, Heeju; Kaiser, Elsi

    2014-01-01

    One of the central questions in speech production is how speakers decide which entity to assign to which grammatical function. According to the lexical hypothesis (e.g., Bock & Levelt, 1994), verbs play a key role in this process (e.g., "send" and "receive" result in different entities being assigned to the subject…

  18. Dual transcriptional activator and repressor roles of TBX20 regulate adult cardiac structure and function

    PubMed Central

    Sakabe, Noboru J.; Aneas, Ivy; Shen, Tao; Shokri, Leila; Park, Soo-Young; Bulyk, Martha L.; Evans, Sylvia M.; Nobrega, Marcelo A.

    2012-01-01

    The ongoing requirement in adult heart for transcription factors with key roles in cardiac development is not well understood. We recently demonstrated that TBX20, a transcriptional regulator required for cardiac development, has key roles in the maintenance of functional and structural phenotypes in adult mouse heart. Conditional ablation of Tbx20 in adult cardiomyocytes leads to a rapid onset and progression of heart failure, with prominent conduction and contractility phenotypes that lead to death. Here we describe a more comprehensive molecular characterization of the functions of TBX20 in adult mouse heart. Coupling genome-wide chromatin immunoprecipitation and transcriptome analyses (RNA-Seq), we identified a subset of genes that change expression in Tbx20 adult cardiomyocyte-specific knockout hearts which are direct downstream targets of TBX20. This analysis revealed a dual role for TBX20 as both a transcriptional activator and a repressor, and that each of these functions regulates genes with very specialized and distinct molecular roles. We also show how TBX20 binds to its targets genome-wide in a context-dependent manner, using various cohorts of co-factors to either promote or repress distinct genetic programs within adult heart. Our integrative approach has uncovered several novel aspects of TBX20 and T-box protein function within adult heart. Sequencing data accession number (http://www.ncbi.nlm.nih.gov/geo): GSE30943. PMID:22328084

  19. Adult Roles & Functions. A Nonlaboratory Home Economics Course for Eleventh and Twelfth Graders.

    ERIC Educational Resources Information Center

    West Virginia State Vocational Curriculum Lab., Cedar Lakes.

    This competency-based curriculum guide is designed for a non-laboratory course in home economics for eleventh and twelfth grades. It was developed and field tested by twenty-nine teachers in high schools in West Virginia. The Adult Roles and Functions curriculum is organized in two sections. The teacher's section contains information on teaching…

  20. The Role and Functionality of Emotions in Feedback at University: A Qualitative Study

    ERIC Educational Resources Information Center

    Rowe, Anna D.; Fitness, Julie; Wood, Leigh N.

    2014-01-01

    This paper reports on a qualitative study exploring the role and functionality of emotions in feedback. In-depth interview data from students and lecturers at an Australian university are analysed using cognitive appraisal and prototype theory. Results suggest that students experience a range of positive and negative emotions in feedback contexts…

  1. The Role of Functional Categories in Bilingual Children's Language Mixing and Differentiation.

    ERIC Educational Resources Information Center

    Rubin, Edward J.; And Others

    1996-01-01

    Examines the simultaneous development of two linguistic competences in the bilingual child. Special attention is devoted to the role of functional categories in the development patterns attested, and a position is taken that is intermediate between two hypotheses: the strong hypothesis and the weak hypothesis. Childhood bilingualism is viewed as a…

  2. Is There a Role for Executive Functions in the Development of Mathematics Ability?

    ERIC Educational Resources Information Center

    Blair, Clancy; Knipe, Hilary; Gamson, David

    2008-01-01

    This article examines the role of working memory, attention shifting, and inhibitory control executive cognitive functions in the development of mathematics knowledge and ability in children. It suggests that an examination of the executive cognitive demand of mathematical thinking can complement procedural and conceptual knowledge-based…

  3. Individual Differences in Early Numeracy: The Role of Executive Functions and Subitizing

    ERIC Educational Resources Information Center

    Kroesbergen, E. H.; Van Luit, J. E. H.; Van Lieshout, E. C. D. M.; Van Loosbroek, E.; Van de Rijt, B. A. M.

    2009-01-01

    In this study, the question was raised how basic cognitive processes are related to math abilities and how it can be best determined which children are at risk for developing those disabilities. The role of four distinct basic processes in the development of early mathematics was investigated: executive functions, fluid intelligence, subitizing,…

  4. The Role of the Executive Functions in School Achievement at the End of Grade 1

    ERIC Educational Resources Information Center

    Monette, Sebastien; Bigras, Marc; Guay, Marie-Claude

    2011-01-01

    The aim of this study was to determine the role of executive functions (EFs) in early school achievement when a variety of potential confounding factors were controlled. Measures of EF (inhibition, flexibility, and working memory) and school readiness were administered to a sample of 85 kindergartners (39 boys and 46 girls, 5-6 years old). School…

  5. The Role of Causal and Intentional Judgments in Moral Reasoning in Individuals with High Functioning Autism

    ERIC Educational Resources Information Center

    Buon, Marine; Dupoux, Emmanuel; Jacob, Pierre; Chaste, Pauline; Leboyer, Marion; Zalla, Tiziana

    2013-01-01

    In the present study, we investigated the ability to assign moral responsibility and punishment in adults with high functioning autism or Asperger Syndrome (HFA/AS), using non-verbal cartoons depicting an aggression, an accidental harm or a mere coincidence. Participants were asked to evaluate the agent's causal and intentional roles, his…

  6. THE ROLE OF CYTOKINES IN REGULATING PROTEIN METABOLISM AND MUSCLE FUNCTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multiple lines of evidence suggest that cytokines influence different physiological functions of skeltal muscle cells, including anabolic and catabolic processes and programmed cell death. Thus, cytokines play an important role not only in muscle homeostasis, but also in the pathogenesis of differen...

  7. Teachers' Understanding of the Role of Executive Functions in Mathematics Learning

    ERIC Educational Resources Information Center

    Gilmore, Camilla; Cragg, Lucy

    2014-01-01

    Cognitive psychology research has suggested an important role for executive functions, the set of skills that monitor and control thought and action, in learning mathematics. However, there is currently little evidence about whether teachers are aware of the importance of these skills and, if so, how they come by this information. We conducted an…

  8. Building-Level Administrators' Perceptions of the Roles and Functions of Professional School Counselors

    ERIC Educational Resources Information Center

    DiDomenico-Sorrento, Tara M.

    2012-01-01

    The aim of this survey research study is to describe and analyze how building-level high school administrators (BLAB) view the roles and functions of professional school counselors (PSCs), particularly as they relate to the National Model of the American Counseling Association (ASCA) that was developed from the ASCA's National Standards. Online…

  9. Time to Get a New Mountain? The Role of Function in Children's Conceptions of Natural Kinds

    ERIC Educational Resources Information Center

    DiYanni, Cara; Kelemen, Deborah

    2005-01-01

    Prior research indicates that young children are promiscuously teleological, attributing purpose not only to artifacts, but also to living and non-living natural entities. This study further examines the role of function in children's reasoning about different object kinds by indirectly probing children's intuitions about what types of entities…

  10. Game Changers: The Quest to Rethink Institutional Roles and Functions at U.S. Community Colleges

    ERIC Educational Resources Information Center

    Woods, Bob

    2014-01-01

    When the 10 members of the American Association of Community College's (AACC's) 21st-Century Implementation Team 7 (nine of whom are community college presidents) sat down in 2013 to talk about reforming institutional roles and functions at the nation's two-year career and technical colleges, everyone in the room knew the work before them would be…

  11. Using NMR spectroscopy to elucidate the role of molecular motions in enzyme function.

    PubMed

    Lisi, George P; Patrick Loria, J

    2016-02-01

    Conformational motions play an essential role in enzyme function, often facilitating the formation of enzyme-substrate complexes and/or product release. Although considerable debate remains regarding the role of molecular motions in the conversion of enzymatic substrates to products, numerous examples have found motions to be crucial for optimization of enzyme scaffolds, effective substrate binding, and product dissociation. Conformational fluctuations are often rate-limiting to enzyme catalysis, primarily through product release, with the chemical reaction occurring much more quickly. As a result, the direct involvement of motions at various stages along the enzyme reaction coordinate remains largely unknown and untested. In the following review, we describe the use of solution NMR techniques designed to probe various timescales of molecular motions and detail examples in which motions play a role in propagating catalytic effects from the active site and directly participate in essential aspects of enzyme function. PMID:26952190

  12. RNA Secondary Structure Modulates FMRP's Bi-Functional Role in the MicroRNA Pathway.

    PubMed

    Kenny, Phillip; Ceman, Stephanie

    2016-01-01

    MicroRNAs act by post-transcriptionally regulating the gene expression of 30%-60% of mammalian genomes. MicroRNAs are key regulators in all cellular processes, though the mechanism by which the cell activates or represses microRNA-mediated translational regulation is poorly understood. In this review, we discuss the RNA binding protein Fragile X Mental Retardation Protein (FMRP) and its role in microRNA-mediated translational regulation. Historically, FMRP is known to function as a translational suppressor. However, emerging data suggests that FMRP has both an agonistic and antagonistic role in regulating microRNA-mediated translational suppression. This bi-functional role is dependent on FMRP's interaction with the RNA helicase Moloney leukemia virus 10 (MOV10), which modifies the structural landscape of bound mRNA, therefore facilitating or inhibiting its association with the RNA-Induced Silencing Complex. PMID:27338369

  13. Plant functional traits mediate reproductive phenology and success in response to experimental warming and snow addition in Tibet.

    PubMed

    Dorji, Tsechoe; Totland, Orjan; Moe, Stein R; Hopping, Kelly A; Pan, Jianbin; Klein, Julia A

    2013-02-01

    Global climate change is predicted to have large impacts on the phenology and reproduction of alpine plants, which will have important implications for plant demography and community interactions, trophic dynamics, ecosystem energy balance, and human livelihoods. In this article we report results of a 3-year, fully factorial experimental study exploring how warming, snow addition, and their combination affect reproductive phenology, effort, and success of four alpine plant species belonging to three different life forms in a semiarid, alpine meadow ecosystem on the central Tibetan Plateau. Our results indicate that warming and snow addition change reproductive phenology and success, but responses are not uniform across species. Moreover, traits associated with resource acquisition, such as rooting depth and life history (early vs. late flowering), mediate plant phenology, and reproductive responses to changing climatic conditions. Specifically, we found that warming delayed the reproductive phenology and decreased number of inflorescences of Kobresia pygmaea C. B. Clarke, a shallow-rooted, early-flowering plant, which may be mainly constrained by upper-soil moisture availability. Because K. pygmaea is the dominant species in the alpine meadow ecosystem, these results may have important implications for ecosystem dynamics and for pastoralists and wildlife in the region. PMID:23504784

  14. Serum Basal Paraoxonase 1 Activity as an Additional Liver Function Test for the Evaluation of Patients with Chronic Hepatitis

    PubMed Central

    Halappa, Chandrakanth K; Pyati, Sudharani A; Nagaraj; Wali, Vinod

    2015-01-01

    Background The diagnostic accuracy of currently available standard panel of liver function tests is not satisfactory for the reliable diagnosis of chronic liver disorders. Earlier studies have reported that serum basal paraoxonase 1 (PON1) activity measurement may add a significant contribution to the liver function tests. Aim To assess whether the measurement of serum basal paraoxonase 1 (PON1) activity would be useful as an index of liver function status in chronic hepatitis patients. Materials and Methods The study included 50 chronic hepatitis patients and 50 apparently healthy controls based on inclusion & exclusion criteria. In all the subjects, standard liver function tests were analysed by using standard methods. Basal PON1 activity was estimated using spectrophotometric method by the hydrolysis of p-nitrophenylacetate. Student t-test, Pearson’s correlation coefficient, diagnostic validity tests and ROC curve analysis were the methods used for the statistical analysis of the data. Results The serum basal PON1 activity was significantly decreased in chronic hepatitis cases when compared to controls (p< 0.001). Also basal PON1 activity was positively correlated with serum total protein and albumin, and negatively correlated with serum total bilirubin, alanine amino transferase (ALT), and alkaline phosphatase (ALP) (p< 0.001) in chronic hepatitis cases but not in healthy controls. Diagnostic validity tests showed, basal PON1 activity was a better discriminator of chronic hepatitis than total protein, albumin and ALP with sensitivity of 68%, specificity of 100%, positive predictive value of 100% and negative predictive value of 75%. ROC curve analysis demonstrated highest diagnostic accuracy for ALT (AUC = 0.999) followed by PON1 (AUC = 0.990), total bilirubin (AUC = 0.977), ALP (AUC = 0.904), total protein (AUC = 0.790) and albumin (AUC = 0.595). Conclusion Diagnostic accuracy of serum PON1 activity is better than total bilirubin, total protein, albumin and

  15. The functional O-mannose glycan on α-dystroglycan contains a phospho-ribitol primed for matriglycan addition.

    PubMed

    Praissman, Jeremy L; Willer, Tobias; Sheikh, M Osman; Toi, Ants; Chitayat, David; Lin, Yung-Yao; Lee, Hane; Stalnaker, Stephanie H; Wang, Shuo; Prabhakar, Pradeep Kumar; Nelson, Stanley F; Stemple, Derek L; Moore, Steven A; Moremen, Kelley W; Campbell, Kevin P; Wells, Lance

    2016-01-01

    Multiple glycosyltransferases are essential for the proper modification of alpha-dystroglycan, as mutations in the encoding genes cause congenital/limb-girdle muscular dystrophies. Here we elucidate further the structure of an O-mannose-initiated glycan on alpha-dystroglycan that is required to generate its extracellular matrix-binding polysaccharide. This functional glycan contains a novel ribitol structure that links a phosphotrisaccharide to xylose. ISPD is a CDP-ribitol (ribose) pyrophosphorylase that generates the reduced sugar nucleotide for the insertion of ribitol in a phosphodiester linkage to the glycoprotein. TMEM5 is a UDP-xylosyl transferase that elaborates the structure. We demonstrate in a zebrafish model as well as in a human patient that defects in TMEM5 result in muscular dystrophy in combination with abnormal brain development. Thus, we propose a novel structure-a ribitol in a phosphodiester linkage-for the moiety on which TMEM5, B4GAT1, and LARGE act to generate the functional receptor for ECM proteins having LG domains. PMID:27130732

  16. The functional O-mannose glycan on α-dystroglycan contains a phospho-ribitol primed for matriglycan addition

    PubMed Central

    Praissman, Jeremy L; Willer, Tobias; Sheikh, M Osman; Toi, Ants; Chitayat, David; Lin, Yung-Yao; Lee, Hane; Stalnaker, Stephanie H; Wang, Shuo; Prabhakar, Pradeep Kumar; Nelson, Stanley F; Stemple, Derek L; Moore, Steven A; Moremen, Kelley W; Campbell, Kevin P; Wells, Lance

    2016-01-01

    Multiple glycosyltransferases are essential for the proper modification of alpha-dystroglycan, as mutations in the encoding genes cause congenital/limb-girdle muscular dystrophies. Here we elucidate further the structure of an O-mannose-initiated glycan on alpha-dystroglycan that is required to generate its extracellular matrix-binding polysaccharide. This functional glycan contains a novel ribitol structure that links a phosphotrisaccharide to xylose. ISPD is a CDP-ribitol (ribose) pyrophosphorylase that generates the reduced sugar nucleotide for the insertion of ribitol in a phosphodiester linkage to the glycoprotein. TMEM5 is a UDP-xylosyl transferase that elaborates the structure. We demonstrate in a zebrafish model as well as in a human patient that defects in TMEM5 result in muscular dystrophy in combination with abnormal brain development. Thus, we propose a novel structure—a ribitol in a phosphodiester linkage—for the moiety on which TMEM5, B4GAT1, and LARGE act to generate the functional receptor for ECM proteins having LG domains. DOI: http://dx.doi.org/10.7554/eLife.14473.001 PMID:27130732

  17. The dual roles of functional groups in the photoluminescence of graphene quantum dots.

    PubMed

    Wang, Shujun; Cole, Ivan S; Zhao, Dongyuan; Li, Qin

    2016-04-14

    The photoluminescent properties of graphene nanoparticle (named graphene quantum dots) have attracted significant research attention in recent years owing to their profound application potential. However, the photoluminescence (PL) origin of this class of nanocarbons is still unclear. In this paper, combining direct experimental evidence enabled by a facile size-tunable oxygenated graphene quantum dots (GQDs) synthesis method and theoretical calculations, the roles of the aromatic core, functional groups and disordered structures (i.e. defects and sp(3) carbon) in the PL of oxygenated GQDs are elucidated in detail. In particular, we found that the functional groups on GQDs play dual roles in the overall emission: (1) they enable π* → n and σ* → n transitions, resulting in a molecular type of PL, spectrally invariable with change of particle size or excitation energy; (2) similar to defects and sp(3) carbon, functional groups also induce structural deformation to the aromatic core, leading to mid-gap states or, in other words, energy traps, causing π* → mid-gap states → π transitions. Therefore, functional groups contribute to both the blue edge and the red shoulder of GQDs' PL spectra. The new insights on the role of functional groups in PL of fluorescent nanocarbons will enable better designs of this new class of materials. PMID:26731007

  18. On the fast evaluation of three-center nuclear attraction integrals using one-range addition theorems for Slater functions

    NASA Astrophysics Data System (ADS)

    Seçkin Görgün, Nurşen

    2013-06-01

    Using one-range addition theorems, the three-center nuclear attraction integrals are expressed through the overlap integrals containing χ - and χ α -Slater-type orbitals (χ -STOs and χ α -STOs), where - ∞ < α ⩽ 2 and \\chi _{nlm}^\\alpha \\left( {\\zeta ,\\vec r} \\right) = \\frac{1}{{\\left( {2\\zeta r} \\right)^\\alpha }}\\chi _{nlm} \\left( {\\zeta ,\\vec r} \\right) . For the fast calculation, the partial summation is utilized for some indices of series expansion relations which correspond to progressively increasing upper limits. The binomial coefficients are stored in the memory of the computer. The convergence and accuracy of series are tested by calculating concrete cases. The best values are obtained for α = 0 .

  19. Non-invasive cardiac index monitoring during cardiopulmonary functional testing provides additional prognostic value in patients after acute heart failure.

    PubMed

    Lee, Ming-Feng; Chen, Wei-Siang; Fu, Tieh-Cheng; Liu, Min-Hui; Wang, Jong-Shyan; Hsu, Chih-Chin; Huang, Yu-Yen; Cherng, Wen-Jin; Wang, Chao-Hung

    2012-01-01

    The prognostic value of parameters derived from a cardiopulmonary exercise test (CPET) is well established in patients stabilized after acute heart failure (HF). Under multidisciplinary disease management, this study sought to test whether noninvasive cardiac output (CO) monitoring (NICOM) during the CPET provides additional prognostic value. In total, 131 patients stabilized after acute HF agreed to undergo the CPET with NICOM. Outcome follow-up focused on composite events of death and HF-related rehospitalization. Patients with a peak cardiac index (CI) of ≤ 4.5 L/minute/ m(2) (n = 32), compared to those with a peak CI of > 4.5 L/minute/m(2) (n = 99), had higher incidences of diabetes mellitus (DM) and hypertension, but had lower hemoglobin levels, estimated glomerular filtration rates (eGFR), oxygen uptake efficiency slope (OUES), and peak oxygen uptake (VO(2)). During the 1.2 ± 0.7 years of follow-up, there were 8 (6.1%) deaths, and 16 (12.2%) HF-related rehospitalizations. In a Cox univariable analysis, a lower event-free survival was associated with a history of DM, a higher Ve/VCO(2) slope, lower peak VCO(2) and eGFR, and a peak CI of ≤ 4.5 L/minute/ m(2) (P < 0.05). The Cox multivariable analysis showed that the Ve/VCO(2) slope (hazard ratio (HR) = 1.08, 95% confidence interval (CI): 1.01~1.16, P = 0.02) and peak CI of ≤ 4.5 L/minute/m(2 )(HR = 3.26, 95% CI: 1.18~9.01, P = 0.02) were significant independent predictors. In conclusion, NICOM during the CPET was demonstrated to provide prognostic information in addition to traditional risk factors, biomarkers, and other well-established CPET parameters. PMID:23258137

  20. Forest soil CO2 fluxes as a function of understory removal and N-fixing species addition.

    PubMed

    Li, Haifang; Fu, Shenglei; Zhao, Hongting; Xia, Hanping

    2011-01-01

    We report on the effects of forest management practices of understory removal and N-fixing species (Cassia alata) addition on soil CO2 fluxes in an Eucalyptus urophylla plantation (EUp), Acacia crassicarpa plantation (ACp), 10-species-mixed plantation (Tp), and 30-species-mixed plantation (THp) using the static chamber method in southern China. Four forest management treatments, including (1) understory removal (UR); (2) C. alata addition (CA); (3) understory removal and replacement with C. alata (UR+CA); and (4) control without any disturbances (CK), were applied in the above four forest plantations with three replications for each treatment. The results showed that soil CO2 fluxes rates remained at a high level during the rainy season (from April to September), followed by a rapid decrease after October reaching a minimum in February. Soil CO2 fluxes were significantly higher (P < 0.01) in EUp (132.6 mg/(m2 x hr)) and ACp (139.8 mg/(m2 x hr)) than in Tp (94.0 mg/(m2 x hr)) and THp (102.9 mg/(m2 x hr)). Soil CO2 fluxes in UR and CA were significantly higher (P < 0.01) among the four treatments, with values of 105.7, 120.4, 133.6 and 112.2 mg/(m2 x hr) for UR+CA, UR, CA and CK, respectively. Soil CO2 fluxes were positively correlated with soil temperature (P < 0.01), soil moisture (P < 0.01), NO3(-)-N (P < 0.05), and litterfall (P < 0.01), indicating that all these factors might be important controlling variables for soil CO2 fluxes. This study sheds some light on our understanding of soil CO2 flux dynamics in forest plantations under various management practices. PMID:22066218

  1. Burst Firing in the Electrosensory System of Gymnotiform Weakly Electric Fish: Mechanisms and Functional Roles

    PubMed Central

    Metzen, Michael G.; Krahe, Rüdiger; Chacron, Maurice J.

    2016-01-01

    Neurons across sensory systems and organisms often display complex patterns of action potentials in response to sensory input. One example of such a pattern is the tendency of neurons to fire packets of action potentials (i.e., a burst) followed by quiescence. While it is well known that multiple mechanisms can generate bursts of action potentials at both the single-neuron and the network level, the functional role of burst firing in sensory processing is not so well understood to date. Here we provide a comprehensive review of the known mechanisms and functions of burst firing in processing of electrosensory stimuli in gymnotiform weakly electric fish. We also present new evidence from existing data showing that bursts and isolated spikes provide distinct information about stimulus variance. It is likely that these functional roles will be generally applicable to other systems and species. PMID:27531978

  2. ROLE OF ATP IN REGULATING RENAL MICROVASCULAR FUNCTION AND IN HYPERTENSION

    PubMed Central

    Guan, Zhengrong; Inscho, Edward W.

    2011-01-01

    Adenosine triphosphate (ATP) is an essential energy substrate for cellular metabolism but it can also influence many biological processes when released into the extracellular milieu. Research has established that extracellular ATP acts as an autocrine/paracrine factor that regulates many physiological functions. Alternatively, excessive extracellular ATP levels contribute to pathophysiological processes such as inflammation, cell proliferation and apoptosis, and atherosclerosis. Renal P2 receptors are widely distributed throughout glomeruli, vasculature and tubular segments, and participate in controlling renal vascular resistance, mediating renal autoregulation, and regulating tubular transport function. This review will focus on the role of ATP-P2 receptor signaling in regulating renal microvascular function and autoregulation, recent advances on the role of ATP-P2 signaling in hypertension-associated renal vascular injury, and emerging new directions. PMID:21768526

  3. Marine reserves lag behind wilderness in the conservation of key functional roles

    PubMed Central

    D'agata, Stéphanie; Mouillot, David; Wantiez, Laurent; Friedlander, Alan M.; Kulbicki, Michel; Vigliola, Laurent

    2016-01-01

    Although marine reserves represent one of the most effective management responses to human impacts, their capacity to sustain the same diversity of species, functional roles and biomass of reef fishes as wilderness areas remains questionable, in particular in regions with deep and long-lasting human footprints. Here we show that fish functional diversity and biomass of top predators are significantly higher on coral reefs located at more than 20 h travel time from the main market compared with even the oldest (38 years old), largest (17,500 ha) and most restrictive (no entry) marine reserve in New Caledonia (South-Western Pacific). We further demonstrate that wilderness areas support unique ecological values with no equivalency as one gets closer to humans, even in large and well-managed marine reserves. Wilderness areas may therefore serve as benchmarks for management effectiveness and act as the last refuges for the most vulnerable functional roles. PMID:27354026

  4. Marine reserves lag behind wilderness in the conservation of key functional roles.

    PubMed

    D'agata, Stéphanie; Mouillot, David; Wantiez, Laurent; Friedlander, Alan M; Kulbicki, Michel; Vigliola, Laurent

    2016-01-01

    Although marine reserves represent one of the most effective management responses to human impacts, their capacity to sustain the same diversity of species, functional roles and biomass of reef fishes as wilderness areas remains questionable, in particular in regions with deep and long-lasting human footprints. Here we show that fish functional diversity and biomass of top predators are significantly higher on coral reefs located at more than 20 h travel time from the main market compared with even the oldest (38 years old), largest (17,500 ha) and most restrictive (no entry) marine reserve in New Caledonia (South-Western Pacific). We further demonstrate that wilderness areas support unique ecological values with no equivalency as one gets closer to humans, even in large and well-managed marine reserves. Wilderness areas may therefore serve as benchmarks for management effectiveness and act as the last refuges for the most vulnerable functional roles. PMID:27354026

  5. Role of Gut Barrier Function in the Pathogenesis of Nonalcoholic Fatty Liver Disease

    PubMed Central

    Dai, Xin; Wang, Bangmao

    2015-01-01

    Nonalcoholic fatty liver disease (NAFLD) is one of the most common forms of chronic liver disease, and its incidence is increasing year by year. Many efforts have been made to investigate the pathogenesis of this disease. Since 1998 when Marshall proposed the conception of “gut-liver axis,” more and more researchers have paid close attention to the role of gut barrier function in the pathogenesis of NAFLD. The four aspects of gut barrier function, including physical, chemical, biological, and immunological barriers, are interrelated closely and related to NAFLD. In this paper, we present a summary of research findings on the relationship between gut barrier dysfunction and the development of NAFLD, aiming at illustrating the role of gut barrier function in the pathogenesis of this disease. PMID:25945084

  6. Functional assessment of perforin C2 domain mutations illustrates the critical role for calcium-dependent lipid binding in perforin cytotoxic function.

    PubMed

    Urrea Moreno, Ramon; Gil, Juana; Rodriguez-Sainz, Carmen; Cela, Elena; LaFay, Victor; Oloizia, Brian; Herr, Andrew B; Sumegi, Janos; Jordan, Michael B; Risma, Kimberly A

    2009-01-01

    Perforin-mediated lymphocyte cytotoxicity is critical for pathogen elimination and immune homeostasis. Perforin disruption of target cell membranes is hypothesized to require binding of a calcium-dependent, lipid-inserting, C2 domain. In a family affected by hemophagocytic lymphohistiocytosis, a severe inflammatory disorder caused by perforin deficiency, we identified 2 amino acid substitutions in the perforin C2 domain: T435M, a previously identified mutant with disputed pathogenicity, and Y438C, a novel substitution. Using biophysical modeling, we predicted that the T435M substitution, but not Y438C, would interfere with calcium binding and thus cytotoxic function. The capacity for cytotoxic function was tested after expression of the variant perforins in rat basophilic leukemia cells and murine cytotoxic T lymphocytes. As predicted, cells transduced with perforin-T435M lacked cytotoxicity, but those expressing perforin-Y438C displayed intact cytotoxic function. Using novel antibody-capture and liposome-binding assays, we found that both mutant perforins were secreted; however, only nonmutated and Y438C-substituted perforins were capable of calcium-dependent lipid binding. In addition, we found that perforin-Y438C was capable of mediating cytotoxicity without apparent proteolytic maturation. This study clearly demonstrates the pathogenicity of the T435M mutation and illustrates, for the first time, the critical role of the human perforin C2 domain for calcium-dependent, cytotoxic function. PMID:18927437

  7. The functional role of all postsynaptic potentials examined from a first-person frame of reference.

    PubMed

    Vadakkan, Kunjumon I

    2016-02-01

    When assigning a central role to the neuronal firing, a large number of incoming postsynaptic potentials not utilized during both supra- and subthreshold neuronal activations are not given any functional significance. Local synaptic potentials at the apical dendrites get attenuated as they arrive at the soma to nearly a twentieth of what a synapse proximal to the soma produces. Conservation of these functions necessitates searching for their functional roles. Potentials induced at the postsynapses of neurons of all the neuronal orders activated by sensory inputs carry small bits of sensory information. The activation of these postsynapses by any means other than the activation from their corresponding presynaptic terminals, that also contribute to oscillating potentials, induce the semblance of the arrival of activity from their presynaptic terminals. This is a candidate mechanism for inducing the first-person internal sensory elements of various higher brain functions as a systems property. They also contribute to the firing of subthreshold-activated neurons, including motor neurons. Operational mechanism of inter-postsynaptic functional LINKs can provide necessary structural requirements for these functions. The functional independence of the distal dendritic compartment and recent evidence for in vivo dendritic spikes indicate their independent role in the formation of internal sensory elements. In these contexts, a neuronal soma is flanked by a large number of quasi-functional internal sensory processing units operated using very little energy, even when a neuron is not firing. A large number of possible combinations of internal sensory units explains the corresponding number of specific memory retrievals by the system in response to various cue stimuli. PMID:26540219

  8. Functional role of induced gamma oscillatory responses in processing noxious and innocuous sensory events in humans.

    PubMed

    Liu, C C; Chien, J H; Chang, Y W; Kim, J H; Anderson, W S; Lenz, F A

    2015-12-01

    Gamma time-frequency responses (TFRs) induced by painful laser in the contralateral primary somatosensory (SI) cortex have been shown to correlate with perceived pain-intensity in human. Given the functional roles of gamma TFRs in the cortical spaces, it remains unclear whether such a relationship is sustained for other brain regions where the laser-evoked potentials (LEPs) are presented. In this study, we delivered the painful laser pluses at random pain-intensity levels (i.e. strong, medium and weak) in a single train to the dorsal hand of six patients with uncontrolled epilepsy. The laser stimulus produced a painful pinprick sensation by activating nociceptors located in the superficial layers of the skin. For each patient, arrays of >64 subdural electrodes were implanted directly covering the contralateral SI, parasylvian (PS) and medial frontal (MF) cortices to study the stimulus related gamma (TFRs) in the neocortex. In addition, using the same stimulation paradigm, the modality specificity of gamma TFRs was further examined by applying innocuous vibrotactile stimuli to the same regions of the dorsal hand in a separated group of five patients. Our results showed that gamma TFRs are not modality specific, but the largest gamma TFRs were consistently found within the SI region and noxious laser elicited significantly stronger gamma TFRs than innocuous nonpainful vibratory stimuli. Furthermore, stronger pain induced stronger gamma TFRs in the cortices of SI (r=0.4, p<0.001) and PS (r=0.29, p=0.005). Given that potentially harmful noxious stimulus would automatically capture greater attention than the innocuous ones, our results support the hypothesis that the degree of SI and PS gamma TFRs is associated with an attentional drive provoked by painful stimuli. PMID:26408986

  9. Role of fluid shear stress in regulating VWF structure, function and related blood disorders

    PubMed Central

    Gogia, Shobhit; Neelamegham, Sriram

    2015-01-01

    Von Willebrand factor (VWF) is the largest glycoprotein in blood. It plays a crucial role in primary hemostasis via its binding interaction with platelet and endothelial cell surface receptors, other blood proteins and extra-cellular matrix components. This protein is found as a series of repeat units that are disulfide bonded to form multimeric structures. Once in blood, the protein multimer distribution is dynamically regulated by fluid shear stress which has two opposing effects: it promotes the aggregation or self-association of multiple VWF units, and it simultaneously reduces multimer size by facilitating the force-dependent cleavage of the protein by various proteases, most notably ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type repeats, motif 1 type 13). In addition to these effects, fluid shear also controls the solution and substrate-immobilized structure of VWF, the nature of contact between blood platelets and substrates, and the biomechanics of the GpIbα–VWF bond. These features together regulate different physiological and pathological processes including normal hemostasis, arterial and venous thrombosis, von Willebrand disease, thrombotic thrombocytopenic purpura and acquired von Willebrand syndrome. This article discusses current knowledge of VWF structure–function relationships with emphasis on the effects of hydrodynamic shear, including rapid methods to estimate the nature and magnitude of these forces in selected conditions. It shows that observations made by many investigators using solution and substrate-based shearing devices can be reconciled upon considering the physical size of VWF and the applied mechanical force in these different geometries. PMID:26600266

  10. Role of fluid shear stress in regulating VWF structure, function and related blood disorders.

    PubMed

    Gogia, Shobhit; Neelamegham, Sriram

    2015-01-01

    Von Willebrand factor (VWF) is the largest glycoprotein in blood. It plays a crucial role in primary hemostasis via its binding interaction with platelet and endothelial cell surface receptors, other blood proteins and extra-cellular matrix components. This protein is found as a series of repeat units that are disulfide bonded to form multimeric structures. Once in blood, the protein multimer distribution is dynamically regulated by fluid shear stress which has two opposing effects: it promotes the aggregation or self-association of multiple VWF units, and it simultaneously reduces multimer size by facilitating the force-dependent cleavage of the protein by various proteases, most notably ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type repeats, motif 1 type 13). In addition to these effects, fluid shear also controls the solution and substrate-immobilized structure of VWF, the nature of contact between blood platelets and substrates, and the biomechanics of the GpIbα-VWF bond. These features together regulate different physiological and pathological processes including normal hemostasis, arterial and venous thrombosis, von Willebrand disease, thrombotic thrombocytopenic purpura and acquired von Willebrand syndrome. This article discusses current knowledge of VWF structure-function relationships with emphasis on the effects of hydrodynamic shear, including rapid methods to estimate the nature and magnitude of these forces in selected conditions. It shows that observations made by many investigators using solution and substrate-based shearing devices can be reconciled upon considering the physical size of VWF and the applied mechanical force in these different geometries. PMID:26600266

  11. NhaA antiporter functions using 10 helices, and an additional 2 contribute to assembly/stability

    PubMed Central

    Padan, Etana; Danieli, Tsafi; Keren, Yael; Alkoby, Dudu; Masrati, Gal; Haliloglu, Turkan; Ben-Tal, Nir; Rimon, Abraham

    2015-01-01

    The Escherichia coli Na+/H+ antiporter (Ec-NhaA) is the best-characterized of all pH-regulated Na+/H+ exchangers that control cellular Na+ and H+ homeostasis. Ec-NhaA has 12 helices, 2 of which (VI and VII) are absent from other antiporters that share the Ec-NhaA structural fold. This α-hairpin is located in the dimer interface of the Ec-NhaA homodimer together with a β-sheet. Here we examine computationally and experimentally the role of the α-hairpin in the stability, dimerization, transport, and pH regulation of Ec-NhaA. Evolutionary analysis (ConSurf) indicates that the VI–VII helical hairpin is much less conserved than the remaining transmembrane region. Moreover, normal mode analysis also shows that intact NhaA and a variant, deleted of the α-hairpin, share similar dynamics, suggesting that the structure may be dispensable. Thus, two truncated Ec-NhaA mutants were constructed, one deleted of the α-hairpin and another also lacking the β-sheet. The mutants were studied at physiological pH in the membrane and in detergent micelles. The findings demonstrate that the truncated mutants retain significant activity and regulatory properties but are defective in the assembly/stability of the Ec-NhaA dimer. PMID:26417087

  12. NhaA antiporter functions using 10 helices, and an additional 2 contribute to assembly/stability.

    PubMed

    Padan, Etana; Danieli, Tsafi; Keren, Yael; Alkoby, Dudu; Masrati, Gal; Haliloglu, Turkan; Ben-Tal, Nir; Rimon, Abraham

    2015-10-13

    The Escherichia coli Na(+)/H(+) antiporter (Ec-NhaA) is the best-characterized of all pH-regulated Na(+)/H(+) exchangers that control cellular Na(+) and H(+) homeostasis. Ec-NhaA has 12 helices, 2 of which (VI and VII) are absent from other antiporters that share the Ec-NhaA structural fold. This α-hairpin is located in the dimer interface of the Ec-NhaA homodimer together with a β-sheet. Here we examine computationally and experimentally the role of the α-hairpin in the stability, dimerization, transport, and pH regulation of Ec-NhaA. Evolutionary analysis (ConSurf) indicates that the VI-VII helical hairpin is much less conserved than the remaining transmembrane region. Moreover, normal mode analysis also shows that intact NhaA and a variant, deleted of the α-hairpin, share similar dynamics, suggesting that the structure may be dispensable. Thus, two truncated Ec-NhaA mutants were constructed, one deleted of the α-hairpin and another also lacking the β-sheet. The mutants were studied at physiological pH in the membrane and in detergent micelles. The findings demonstrate that the truncated mutants retain significant activity and regulatory properties but are defective in the assembly/stability of the Ec-NhaA dimer. PMID:26417087

  13. Basic-functionalized recyclable ionic liquid catalyst: A solvent-free approach for Michael addition of 1,3-dicarbonyl compounds to nitroalkenes under ultrasound irradiation.

    PubMed

    Narayanaperumal, Senthil; da Silva, Rodrigo César; Feu, Karla Santos; de la Torre, Alexander Fernández; Corrêa, Arlene G; Paixão, Márcio Weber

    2013-05-01

    A task-specific ionic liquid (TSIL) has been introduced as a recyclable catalyst in Michael addition. A series of nitroalkenes and various C-based nucleophiles were reacted in the presence of 30mol% of recyclable basic-functionalized ionic liquid. Good to excellent yields were obtained in 30min under ultrasound irradiation. PMID:23218731

  14. The functional role of Cys3-Cys4 loop in hydrophobin HGFI.

    PubMed

    Niu, Baolong; Gong, Yanbo; Gao, Xianghua; Xu, Haijin; Qiao, Mingqiang; Li, Wenfeng

    2014-11-01

    Hydrophobins are a large group of low-molecular weight proteins. These proteins are highly surface-active and can form amphipathic membranes by self-assembling at hydrophobic-hydrophilic interfaces. Based on physical properties and hydropathy profiles, hydrophobins are divided into two classes. Upon the analysis of amino acid sequences and higher structures, some models suggest that the Cys3-Cys4 loop regions in class I and II hydrophobins can exhibit remarkable difference in their alignment and conformation, and have a critical role in the rodlets structure formation. To examine the requirement for the Cys3-Cys4 loop in class I hydrophobins, we used protein fusion technology to obtain a mutant protein HGFI-AR by replacing the amino acids between Cys3 and Cys4 of the class I hydrophobin HGFI from Grifola frondosa with those ones between Cys3 and Cys4 of the class II hydrophobin HFBI from Trichoderma reesei. The gene of the mutant protein HGFI-AR was successfully expressed in Pichia pastoris. Water contact angle (WCA) and X-ray photoelectron spectroscopy (XPS) measurements demonstrated that the purified HGFI-AR could form amphipathic membranes by self-assembling at mica and hydrophobic polystyrene surfaces. This property enabled them to alter the surface wettabilities of polystyrene and mica and change the elemental composition of siliconized glass. In comparison to recombinant class I hydrophobin HGFI (rHGFI), the membranes formed on hydrophobic surfaces by HGFI-AR were not robust enough to resist 1 % hot SDS washing. Atomic force microscopy (AFM) measurements indicated that unlike rHGFI, no rodlet structure was observed on the mutant protein HGFI-AR coated mica surface. In addition, when compared to rHGFI, no secondary structural change was detected by Circular Dichroism (CD) spectroscopy after HGFI-AR self-assembled at the water-air interface. HGFI-AR could not either be deemed responsible for the fluorescence intensity increase of Thioflavin T (THT) and the

  15. ALDH3A1 Plays a Functional Role in Maintenance of Corneal Epithelial Homeostasis

    PubMed Central

    Mehta, Gaurav; Orlicky, David J.; Thompson, David C.; Jester, James V.; Vasiliou, Vasilis

    2016-01-01

    Aldehyde dehydrogenase 1A1 (ALDH1A1) and ALDH3A1 are corneal crystallins. They protect inner ocular tissues from ultraviolet radiation (UVR)-induced oxidative damage through catalytic and non-catalytic mechanisms. Additionally, ALDH3A1 has been postulated to play a regulatory role in the corneal epithelium based on several studies that report an inverse association between ALDH3A1 expression and corneal cell proliferation. The underlying molecular mechanisms and the physiological significance of such association remain poorly understood. In the current study, we established Tet-On human corneal epithelial cell (hTCEpi) lines, which express tetracycline-inducible wild-type (wt) or catalytically-inactive (mu) ALDH3A1. Utilizing this cellular model system, we confirmed that human ALDH3A1 decreases corneal cell proliferation; importantly, this effect appears to be partially mediated by its enzymatic activity. Mechanistically, wt-ALDH3A1, but not mu-ALDH3A1, promotes sequestering of tumor suppressor p53 in the nucleus. In the mouse cornea, however, augmented cell proliferation is noted only in Aldh1a1-/-/3a1-/- double knockout (DKO) mice, indicating in vivo the anti-proliferation effect of ALDH3A1 can be rescued by the presence of ALDH1A1. Interestingly, the hyper-proliferative epithelium of the DKO corneas display nearly complete loss of p53 expression, implying that p53 may be involved in ALDH3A1/1A1-mediated effect. In hTCEpi cells grown in high calcium concentration, mRNA levels of a panel of corneal differentiation markers were altered by ALDH3A1 expression and modulated by its enzyme activity. In conclusion, we show for the first time that: (i) ALDH3A1 decreases corneal epithelial proliferation through both non-enzymatic and enzymatic properties; (ii) ALDH1A1 contributes to the regulation of corneal cellular proliferation in vivo; and (iii) ALDH3A1 modulates corneal epithelial differentiation. Collectively, our studies indicate a functional role of ALDH3A1 in the

  16. Role of Y{sub 2}O{sub 3}, CaO, MgO additives on structural and microstructural behavior of zirconia/mullite aggregates

    SciTech Connect

    Mishra, D. K.; Prusty, Sasmita; Mohapatra, B. K.; Singh, S. K.; Behera, S. N.

    2012-07-23

    Zirconia mullite (MUZ), Y{sub 2}O{sub 3}-MUZ, CaO-MUZ and MgO-MUZ composites, synthesized through plasma fusion technique, are becoming important due to their commercial scale of production within five minutes of plasma treatment from sillimanite, zircon and alumina mixture. The X-ray diffraction studies reveal the monoclinic zirconia phase in MUZ composite whereas mixed monoclinic, tetragonal and cubic phases of zirconia have been observed in Y{sub 2}O{sub 3}, CaO, MgO added MUZ composites. The Y{sub 2}O{sub 3}, CaO and MgO additives act as sintering aids to favour the transformation and stabilisation of tetragonal and cubic zirconia phases at room temperature. These additives also play a key role in the development of various forms of microstructure to achieve dense MUZ composites.

  17. The Functions of Mediator in Candida albicans Support a Role in Shaping Species-Specific Gene Expression

    PubMed Central

    Jelicic, Branka; Lo, Tricia L.; Beaurepaire, Cecile; Bantun, Farkad; Quenault, Tara; Boag, Peter R.; Ramm, Georg; Callaghan, Judy; Beilharz, Traude H.; Nantel, André; Peleg, Anton Y.; Traven, Ana

    2012-01-01

    The Mediator complex is an essential co-regulator of RNA polymerase II that is conserved throughout eukaryotes. Here we present the first study of Mediator in the pathogenic fungus Candida albicans. We focused on the Middle domain subunit Med31, the Head domain subunit Med20, and Srb9/Med13 from the Kinase domain. The C. albicans Mediator shares some roles with model yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, such as functions in the response to certain stresses and the role of Med31 in the expression of genes regulated by the activator Ace2. The C. albicans Mediator also has additional roles in the transcription of genes associated with virulence, for example genes related to morphogenesis and gene families enriched in pathogens, such as the ALS adhesins. Consistently, Med31, Med20, and Srb9/Med13 contribute to key virulence attributes of C. albicans, filamentation, and biofilm formation; and ALS1 is a biologically relevant target of Med31 for development of biofilms. Furthermore, Med31 affects virulence of C. albicans in the worm infection model. We present evidence that the roles of Med31 and Srb9/Med13 in the expression of the genes encoding cell wall adhesins are different between S. cerevisiae and C. albicans: they are repressors of the FLO genes in S. cerevisiae and are activators of the ALS genes in C. albicans. This suggests that Mediator subunits regulate adhesion in a distinct manner between these two distantly related fungal species. PMID:22496666

  18. An Alkaline Protease from Bacillus pumilus MP 27: Functional Analysis of Its Binding Model toward Its Applications As Detergent Additive

    PubMed Central

    Baweja, Mehak; Tiwari, Rameshwar; Singh, Puneet K.; Nain, Lata; Shukla, Pratyoosh

    2016-01-01

    A proteolytic strain of Bacillus pumilus MP 27 was isolated from water samples of Southern ocean produced alkaline protease. Since protease production need expensive ingredients, an economically viable process was developed by using low cost carbon source, wheat straw, supplemented with peptone. This protease was active within temperature ranges 10–70°C at pH 9. This process was optimized by response surface methodology using a Box Bekhman design by Design Expert 7.0 software that increased the protease activity to 776.5 U/ml. Moreover, the enzyme was extremely stable at a broad range of temperature and pH retaining 69% of its activity at 50°C and 70% at pH 11. The enzyme exhibited excellent compatibility with surfactants and commercial detergents, showing 87% stability with triton X-100 and 100% stability with Tide commercial detergent. The results of the wash performance analysis demonstrated considerably good de-staining at 50 and 4°C with low supplementation (109 U/ml). Molecular modeling of the protease revealed the presence of serine proteases, subtilase family and serine active site and further docking supported the association of catalytic site with the various substrates. Certainly, such protease can be considered as a good detergent additive in detergent industry with a possibility to remove the stains effectively even in a cold wash. PMID:27536284

  19. An Alkaline Protease from Bacillus pumilus MP 27: Functional Analysis of Its Binding Model toward Its Applications As Detergent Additive.

    PubMed

    Baweja, Mehak; Tiwari, Rameshwar; Singh, Puneet K; Nain, Lata; Shukla, Pratyoosh

    2016-01-01

    A proteolytic strain of Bacillus pumilus MP 27 was isolated from water samples of Southern ocean produced alkaline protease. Since protease production need expensive ingredients, an economically viable process was developed by using low cost carbon source, wheat straw, supplemented with peptone. This protease was active within temperature ranges 10-70°C at pH 9. This process was optimized by response surface methodology using a Box Bekhman design by Design Expert 7.0 software that increased the protease activity to 776.5 U/ml. Moreover, the enzyme was extremely stable at a broad range of temperature and pH retaining 69% of its activity at 50°C and 70% at pH 11. The enzyme exhibited excellent compatibility with surfactants and commercial detergents, showing 87% stability with triton X-100 and 100% stability with Tide commercial detergent. The results of the wash performance analysis demonstrated considerably good de-staining at 50 and 4°C with low supplementation (109 U/ml). Molecular modeling of the protease revealed the presence of serine proteases, subtilase family and serine active site and further docking supported the association of catalytic site with the various substrates. Certainly, such protease can be considered as a good detergent additive in detergent industry with a possibility to remove the stains effectively even in a cold wash. PMID:27536284

  20. Design and analysis of a piezoelectric material based touch screen with additional pressure and its acceleration measurement functions

    NASA Astrophysics Data System (ADS)

    Chu, Xiang-Cheng; Liu, Jia-Yi; Gao, Ren-Long; Chang, Jie; Li, Long-Tu

    2013-12-01

    Touch screens are becoming more and more prevalent in everyday environments due to their convenience and humanized operation. In this paper, a piezoelectric material based touch screen is developed and investigated. Piezoelectric ceramics arrayed under the touch panel at the edges or corners are used as tactile sensors to measure the touch positioning point similarly to conventional touch screens. However, additional touch pressure and its acceleration performance can also be obtained to obtain a higher-level human-machine interface. The piezoelectric ceramics can also be added to a traditional touch screen structure, or they can be used independently to construct a novel touch screen with a high light transmittance approach to a transparent glass. The piezoelectric ceramics were processed from PZT piezoelectric ceramic powder into a round or rectangular shape. According to the varied touch position and physical press strength of a finger, or even a gloved hand or fingernail, the piezoelectric tactile sensors will have different output voltage responses. By calculating the ratio of different piezoelectric tactile sensors’ responses and summing up all piezoelectric tactile sensors’ output voltages, the touch point position, touch pressure and touch force acceleration can be detected. A prototype of such a touch screen is manufactured and its position accuracy, touch pressure and response speed are measured in detail. The experimental results show that the prototype has many advantages such as high light transmittance, low energy cost and high durability.

  1. Integral Role of GDF-9 and BMP-15 in Ovarian Function

    PubMed Central

    Otsuka, Fumio; McTavish, Kirsten; Shimasaki, Shunichi

    2011-01-01

    The oocyte plays an important role in regulating and promoting follicle growth, and thereby its own development, by the production of oocyte growth factors that predominantly act on supporting granulosa cells via paracrine signaling. Genetic studies in mice demonstrated critical roles of two key oocyte-derived growth factors belonging to the transforming growth factor-β (TGF-β) superfamily, growth and differentiation factor-9 (GDF-9) and bone morphogenetic protein-15 (BMP-15) in ovarian function. The identification of Bmp15 and Gdf9 gene mutations as the causal mechanism underlying the highly prolific or infertile nature of several sheep strains in a dosage-sensitive manner also highlighted the crucial role these two genes play in ovarian function. Similarly, large numbers of mutations in the GDF9 and BMP15 genes have been identified in women with premature ovarian failure and in mothers of dizygotic twins. The purpose of this article is to review the genetic studies of GDF-9 and BMP-15 mutations identified in women and sheep as well as describing the various knockout and over-expressing mouse models, and to summarize the molecular and biological functions that underlie the crucial role of these two oocyte factors in female fertility. PMID:21226076

  2. A Non-Additive Interaction of a Functional MAO-A VNTR and Testosterone Predicts Antisocial Behavior

    PubMed Central

    Sjöberg, Rickard L; Ducci, Francesca; Barr, Christina S; Newman, Timothy K; Dell'Osso, Liliana; Virkkunen, Matti; Goldman, David

    2008-01-01

    A functional VNTR polymorphism in the promoter of the monoamine oxidase A gene (MAOA-LPR) has previously been shown to be an important predictor of antisocial behavior in men. Testosterone analogues are known to interact with the MAOA promoter in vitro to influence gene transcription as well as in vivo to influence CSF levels of the MAO metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG) in human males. We examined the possible joint effects of testosterone (measured in CSF) and MAOA-LPR genotype on antisocial personality disorder and scores on the Brown–Goodwin Aggression scale in 95 unrelated male criminal alcoholics and 45 controls. The results confirm that MAOA genotype and CSF testosterone interact to predict antisocial behaviors. The MAOA/testosterone interaction also predicted low levels of CSF MHPG, which tentatively suggests the possibility that the interaction may be mediated by a direct effect on gene transcription. If replicated these findings offer plausible explanations for previous inconsistencies in studies of the relationship between testosterone and male human aggression, as well as for how MAOA genotype may influence aggressive behavior in human males. PMID:17429405

  3. A non-additive interaction of a functional MAO-A VNTR and testosterone predicts antisocial behavior.

    PubMed

    Sjöberg, Rickard L; Ducci, Francesca; Barr, Christina S; Newman, Timothy K; Dell'osso, Liliana; Virkkunen, Matti; Goldman, David

    2008-01-01

    A functional VNTR polymorphism in the promoter of the monoamine oxidase A gene (MAOA-LPR) has previously been shown to be an important predictor of antisocial behavior in men. Testosterone analogues are known to interact with the MAOA promoter in vitro to influence gene transcription as well as in vivo to influence CSF levels of the MAO metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG) in human males. We examined the possible joint effects of testosterone (measured in CSF) and MAOA-LPR genotype on antisocial personality disorder and scores on the Brown-Goodwin Aggression scale in 95 unrelated male criminal alcoholics and 45 controls. The results confirm that MAOA genotype and CSF testosterone interact to predict antisocial behaviors. The MAOA/testosterone interaction also predicted low levels of CSF MHPG, which tentatively suggests the possibility that the interaction may be mediated by a direct effect on gene transcription. If replicated these findings offer plausible explanations for previous inconsistencies in studies of the relationship between testosterone and male human aggression, as well as for how MAOA genotype may influence aggressive behavior in human males. PMID:17429405

  4. Effect of COOH-functionalized SWCNT addition on the electrical and photovoltaic characteristics of Malachite Green dye based photovoltaic cells

    NASA Astrophysics Data System (ADS)

    Chakraborty, S.; Manik, N. B.

    2014-12-01

    We report the effect of COOH-functionalized single walled carbon nanotubes (COOH-SWCNT) on the electrical and photovoltaic characteristics of Malachite Green (MG) dye based photovoltaic cells. Two different types of photovoltaic cells were prepared, one with MG dye and another by incorporating COOH-SWCNT with this dye. Cells were characterized through different electrical and photovoltaic measurements including photocurrent measurements with pulsed radiation. From the dark current—voltage (I-V) characteristic results, we observed a certain transition voltage (Vth) for both the cells beyond which the conduction mechanism of the cells change sharply. For the MG dye, Vth is 3.9 V whereas for COOH-SWCNT mixed with this dye, Vth drops to 2.7 V. The device performance improves due to the incorporation of COOH-SWCNT. The open circuit voltage and short circuit current density change from 4.2 to 97 mV and from 108 to 965 μA/cm2 respectively. Observations from photocurrent measurements show that the rate of growth and decay of the photocurrent are quite faster in the presence of COOH-SWCNT. This observation indicates a faster charge separation processes due to the incorporation of COOH-SWCNT in the MG dye cells. The high aspect ratio of COOH-SWCNT allows efficient conduction pathways for the generated charge carriers.

  5. The functional role of the alpha-1 adrenergic receptors in cerebral blood flow regulation

    PubMed Central

    Purkayastha, Sushmita; Raven, Peter B.

    2011-01-01

    Cerebral vasculature is richly innervated by the α-1 adrenergic receptors similar to that of the peripheral vasculature. However, the functional role of the α-1adrenergic receptors in cerebral blood flow (CBF) regulation is yet to be established. The traditional thinking being that during normotension and normocapnia sympathetic neural activity does not play a significant role in CBF regulation. Reports in the past have stated that catecholamines do not penetrate the blood brain barrier (BBB) and therefore only influence cerebral vessels from outside the BBB and hence, have a limited role in CBF regulation. However, with the advent of dynamic measurement techniques, beat-to-beat CBF assessment can be done during dynamic changes in arterial blood pressure. Several studies in the recent years have reported a functional role of the α-1adrenergic receptors in CBF regulation. This review focuses on the recent developments on the role of the sympathetic nervous system, specifically that of the α-1 adrenergic receptors in CBF regulation. PMID:22021989

  6. Genetic and functional analyses demonstrate a role for abnormal glycinergic signaling in autism.

    PubMed

    Pilorge, M; Fassier, C; Le Corronc, H; Potey, A; Bai, J; De Gois, S; Delaby, E; Assouline, B; Guinchat, V; Devillard, F; Delorme, R; Nygren, G; Råstam, M; Meier, J C; Otani, S; Cheval, H; James, V M; Topf, M; Dear, T N; Gillberg, C; Leboyer, M; Giros, B; Gautron, S; Hazan, J; Harvey, R J; Legendre, P; Betancur, C

    2016-07-01

    Autism spectrum disorder (ASD) is a common neurodevelopmental condition characterized by marked genetic heterogeneity. Recent studies of rare structural and sequence variants have identified hundreds of loci involved in ASD, but our knowledge of the overall genetic architecture and the underlying pathophysiological mechanisms remains incomplete. Glycine receptors (GlyRs) are ligand-gated chloride channels that mediate inhibitory neurotransmission in the adult nervous system but exert an excitatory action in immature neurons. GlyRs containing the α2 subunit are highly expressed in the embryonic brain, where they promote cortical interneuron migration and the generation of excitatory projection neurons. We previously identified a rare microdeletion of the X-linked gene GLRA2, encoding the GlyR α2 subunit, in a boy with autism. The microdeletion removes the terminal exons of the gene (GLRA2(Δex8-9)). Here, we sequenced 400 males with ASD and identified one de novo missense mutation, p.R153Q, absent from controls. In vitro functional analysis demonstrated that the GLRA2(Δex8)(-)(9) protein failed to localize to the cell membrane, while the R153Q mutation impaired surface expression and markedly reduced sensitivity to glycine. Very recently, an additional de novo missense mutation (p.N136S) was reported in a boy with ASD, and we show that this mutation also reduced cell-surface expression and glycine sensitivity. Targeted glra2 knockdown in zebrafish induced severe axon-branching defects, rescued by injection of wild type but not GLRA2(Δex8-9) or R153Q transcripts, providing further evidence for their loss-of-function effect. Glra2 knockout mice exhibited deficits in object recognition memory and impaired long-term potentiation in the prefrontal cortex. Taken together, these results implicate GLRA2 in non-syndromic ASD, unveil a novel role for GLRA2 in synaptic plasticity and learning and memory, and link altered glycinergic signaling to social and cognitive

  7. Suppressing Respiration Effects when Geometric Distortion Is Corrected Dynamically by Phase Labeling for Additional Coordinate Encoding (PLACE) during Functional MRI

    PubMed Central

    Faraji-Dana, Zahra; Tam, Fred; Chen, J. Jean; Graham, Simon J.

    2016-01-01

    Echo planar imaging (EPI) suffers from geometric distortions caused by magnetic field inhomogeneities, which can be time-varying as a result of small amounts of head motion that occur over seconds and minutes during fMRI experiments, also known as “dynamic geometric distortion”. Phase Labeling for Additional Coordinate Encoding (PLACE) is a promising technique for geometric distortion correction without reduced temporal resolution and in principle can be used to correct for motion-induced dynamic geometric distortion. PLACE requires at least two EPI images of the same anatomy that are ideally acquired with no variation in the magnetic field inhomogeneities. However, head motion and lung ventilation during the respiratory cycle can cause changes in magnetic field inhomogeneities within the EPI pair used for PLACE. In this work, we exploited dynamic off-resonance in k-space (DORK) and averaging to correct the within EPI pair magnetic field inhomogeneities; and hence proposed a combined technique (DORK+PLACE+averaging) to mitigate dynamic geometric distortion in EPI-based fMRI while preserving the temporal resolution. The performance of the combined DORK, PLACE and averaging technique was characterized through several imaging experiments involving test phantoms and six healthy adult volunteers. Phantom data illustrate reduced temporal standard deviation of fMRI signal intensities after use of combined dynamic PLACE, DORK and averaging compared to the standard processing and static geometric distortion correction. The combined technique also substantially improved the temporal standard deviation and activation maps obtained from human fMRI data in comparison to the results obtained by standard processing and static geometric distortion correction, highlighting the utility of the approach. PMID:27258194

  8. Looking for the role of cannabinoid receptor heteromers in striatal function.

    PubMed

    Ferré, Sergi; Goldberg, Steven R; Lluis, Carme; Franco, Rafael

    2009-01-01

    The introduction of two concepts, "local module" and "receptor heteromer", facilitates the understanding of the role of interactions between different neurotransmitters in the brain. In artificial cell systems, cannabinoid CB(1) receptors form receptor heteromers with dopamine D2, adenosine A2A and mu opioid receptors. There is indirect but compelling evidence for the existence of the same CB1 receptor heteromers in striatal local modules centered in the dendritic spines of striatal GABAergic efferent neurons, particularly at a postsynaptic location. Their analysis provides new clues for the role of endocannabinoids in striatal function, which cannot only be considered as retrograde signals that inhibit neurotransmitter release. Recent studies using a new method to detect heteromerization of more than two proteins, which consists of sequential BRET-FRET (SRET) analysis, has demonstrated that CB1, D2 and A2A receptors can form heterotrimers in transfected cells. It is likely that functional CB1-A2A-D2 receptor heteromers can be found where they are highly co-expressed, in the dendritic spines of GABAergic enkephalinergic neurons. The functional properties of these multiple receptor heteromers and their role in striatal function need to be determined. PMID:18691604

  9. A new functional role of HIV-1 integrase during uncoating of the viral core.

    PubMed

    Briones, Marisa S; Chow, Samson A

    2010-12-01

    An early and critical event of the human immunodeficiency virus type 1 (HIV-1) life cycle is uncoating of the viral core. Uncoating involves the disassembly of HIV-1 capsid (CA). The underlying mechanisms governing uncoating are poorly defined, and the role of viral and host factors in uncoating is not well understood. Cyclophilin A and TRIM5α are two cellular factors that interact with CA in exerting their effects on HIV-1 replication. Here, we review the current understanding of uncoating and the new functional role of HIV-1 IN during uncoating. PMID:20721640

  10. Civil Society Organizations and the Functions of Global Health Governance: What Role within Intergovernmental Organizations?

    PubMed Central

    Lee, Kelley

    2016-01-01

    Amid discussion of how global health governance should and could be strengthened, the potential role of civil society organizations has been frequently raised. This paper considers the role of Civil Society Organizations (CSOs) in four health governance instruments under the auspices of the World Health Organization – the International Code on the Marketing of Breastmilk Substitutes, Framework Convention on Tobacco Control, International Health Regulations and Codex Alimentarius - and maps the functions they have contributed to. The paper draws conclusions about the opportunities and limitations CSOs represent for strengthening global health governance (GHG). PMID:27274776

  11. Evaluation of calcium and lead interaction, in addition to their impact on thyroid functions in hyper and hypothyroid patients.

    PubMed

    Memon, Nusrat Shahab; Kazi, Tasneem Gul; Afridi, Hassan Imran; Baig, Jameel Ahmed; Arain, Sadaf Sadia; Sahito, Oan Muhammad; Baloch, Shahnawaz; Waris, Muhammad

    2016-01-01

    There is compelling evidence in support of interaction between calcium (Ca) and lead (Pb) in thyroid disorders. The aim of present study was to compare the level of Ca and Pb with thyroid hormones such as thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxin (FT4) in serum samples of hyperthyroid (HPRT) and hypothyroid (HPOT) patients of both genders. For comparative purpose, age-matched (25-50 years) subjects having no thyroid disorders were selected as referents/controls. The serum samples were acid-digested prior to analysis by atomic absorption spectrometry. The validity and accuracy of the methodology were checked by certified reference materials. The resulted data indicates that the mean values of Ca in serum samples of HPRT patients were significantly higher than those of referent subjects (p < 0.01), while reverse pattern was observed in the case of HPOT patients. The level of Pb was higher in the serum samples of both types of thyroid patients, but difference was significant in case of HPOT patients as compare to referent subjects (p < 0.01). A negative correlation was observed between serum Ca levels and TSH of HPRT patients (-r = 0.37-0.39, p < 0.01), while FT3 and FT4 have positive correlation (r = 0.49-0.52 and r = 0.46-0.47), p values <0.01. The Pb in serum had positive correlation with TSH (r = 0.48-0.51, p < 0.005), while negative correlation was observed for FT3 and FT4 (-r = 0.55-0.56, 0.5-0.54, p < 0.05) in HPRT patients. On the other hand, a reverse pattern was observed, for correlation of Ca and Pb with thyroid functions in HPOT patients. PMID:26347420

  12. The Role of Acculturation and Family Functioning in Predicting HIV Risk Behaviors Among Hispanic Delinquent Youth

    PubMed Central

    Farrelly, Colleen; Cordova, David; Huang, Shi; Estrada, Yannine

    2012-01-01

    The present study examined the relationship between Berry’s acculturation typology and HIV risk behaviors and whether family functioning mediated any such effects. A total of 235 high risk Hispanic adolescents were categorized into one of Berry’s four acculturation typologies through the use of cut-off scores on measures of Hispanicism and Americanism. Structural equation modeling was used to examine the effects of acculturation typology on HIV risk behaviors and the indirect effects of acculturation typology on HIV risk behaviors through family functioning. Acculturation typology was related to HIV risk behaviors. Family functioning partially mediated the effects of acculturation typology on the HIV risk behavior outcomes. These findings suggest that both Americanism and Hispanicism play an important role in the etiology of HIV risk behaviors among Hispanic youth and that both, along with family functioning, are important to consider when designing preventive interventions for this population. PMID:22532299

  13. The role of acculturation and family functioning in predicting HIV risk behaviors among Hispanic delinquent youth.

    PubMed

    Farrelly, Colleen; Cordova, David; Huang, Shi; Estrada, Yannine; Prado, Guillermo

    2013-06-01

    The present study examined the relationship between Berry's acculturation typology and HIV risk behaviors and whether family functioning mediated any such effects. A total of 235 high risk Hispanic adolescents were categorized into one of Berry's four acculturation typologies through the use of cut-off scores on measures of Hispanicism and Americanism. Structural equation modeling was used to examine the effects of acculturation typology on HIV risk behaviors and the indirect effects of acculturation typology on HIV risk behaviors through family functioning. Acculturation typology was related to HIV risk behaviors. Family functioning partially mediated the effects of acculturation typology on the HIV risk behavior outcomes. These findings suggest that both Americanism and Hispanicism play an important role in the etiology of HIV risk behaviors among Hispanic youth and that both, along with family functioning, are important to consider when designing preventive interventions for this population. PMID:22532299

  14. Functional profiles reveal unique ecological roles of various biological soil crust organisms

    USGS Publications Warehouse

    Bowker, M.A.; Mau, R.L.; Maestre, F.T.; Escolar, C.; Castillo-Monroy, A. P.

    2011-01-01

    1. At the heart of the body of research on biodiversity effects on ecosystem function is the debate over whether different species tend to be functionally singular or redundant. When we consider ecosystem multi-function, the provision of multiple ecosystem functions simultaneously, we may find that seemingly redundant species may in fact play unique roles in ecosystems. 2. Over the last few decades, the significance of biological soil crusts (BSCs) as ecological boundaries and ecosystem engineers, and their multi-functional nature, has become increasingly well documented. We compiled 'functional profiles' of the organisms in this understudied community, to determine whether functional singularity emerges when multiple ecosystem functions are considered. 3. In two data sets, one representing multiple sites around the semi-arid regions of Spain (regional scale), and another from a single site in central Spain (local scale), we examined correlations between the abundance or frequency of BSC species in a community, and multiple surrogates of ecosystem functioning. There was a wide array of apparent effects of species on specific functions. 4. Notably, in gypsiferous soils and at regional scale, we found that indicators of carbon (C) and phosphorus cycling were apparently suppressed and promoted by the lichens Diploschistes diacapsis and Squamarina lentigera, respectively. The moss Pleurochaete squarrosa appears to promote C cycling in calcareous soils at this spatial scale. At the local scale in gypsiferous soils, D. diacapsis positively correlated with carbon cycling, but negatively with nitrogen cycling, whereas numerous lichens exhibited the opposite profile. 5. We found a high degree of functional singularity, i.e. that species were highly individualistic in their effects on multiple functions. Many functional attributes were not easily predictable from existing functional grouping systems based primarily on morphology. 6. Our results suggest that maintaining

  15. An Ongoing Role for Structural Sarcomeric Components in Maintaining Drosophila melanogaster Muscle Function and Structure

    PubMed Central

    Perkins, Alexander D.; Tanentzapf, Guy

    2014-01-01

    Animal muscles must maintain their function while bearing substantial mechanical loads. How muscles withstand persistent mechanical strain is presently not well understood. The basic unit of muscle is the sarcomere, which is primarily composed of cytoskeletal proteins. We hypothesized that cytoskeletal protein turnover is required to maintain muscle function. Using the flight muscles of Drosophila melanogaster, we confirmed that the sarcomeric cytoskeleton undergoes turnover throughout adult life. To uncover which cytoskeletal components are required to maintain adult muscle function, we performed an RNAi-mediated knockdown screen targeting the entire fly cytoskeleton and associated proteins. Gene knockdown was restricted to adult flies and muscle function was analyzed with behavioural assays. Here we analyze the results of that screen and characterize the specific muscle maintenance role for several hits. The screen identified 46 genes required for muscle maintenance: 40 of which had no previously known role in this process. Bioinformatic analysis highlighted the structural sarcomeric proteins as a candidate group for further analysis. Detailed confocal and electron microscopic analysis showed that while muscle architecture was maintained after candidate gene knockdown, sarcomere length was disrupted. Specifically, we found that ongoing synthesis and turnover of the key sarcomere structural components Projectin, Myosin and Actin are required to maintain correct sarcomere length and thin filament length. Our results provide in vivo evidence of adult muscle protein turnover and uncover specific functional defects associated with reduced expression of a subset of cytoskeletal proteins in the adult animal. PMID:24915196

  16. The roles of evolutionarily conserved functional modules in cilia-related trafficking

    PubMed Central

    Sung, Ching-Hwa; Leroux, Michel R.

    2014-01-01

    Cilia are present across most eukaryotic phyla and have diverse sensory and motility roles in animal physiology, cell signalling and development. Their biogenesis and maintenance depend on vesicular and intraciliary (intraflagellar) trafficking pathways that share conserved structural and functional modules. The functional units of the interconnected pathways, which include proteins involved in membrane coating as well as small GTPases and their accessory factors, were first experimentally associated with canonical vesicular trafficking. These components are, however, ancient, having been co-opted by the ancestral eukaryote to establish the ciliary organelle, and their study can inform us about ciliary biology in higher organisms. PMID:24296415

  17. The emerging role of pseudogene expressed non-coding RNAs in cellular functions

    PubMed Central

    Groen, Jessica N.; Capraro, David; Morris, Kevin V.

    2014-01-01

    A paradigm shift is sweeping modern day molecular biology following the realisation that large amounts of “junk” DNA”, thought initially to be evolutionary remnants, may actually be functional. Several recent studies support a functional role for pseudogene-expressed non-coding RNAs in regulating their protein-coding counterparts. Several hundreds of pseudogenes have been reported as transcribed into RNA in a large variety of tissues and tumours. Most studies have focused on pseudogenes expressed in the sense direction, but some reports suggest that pseudogenes can also be transcribed as antisense RNAs (asRNAs). A few examples of key regulatory genes, such as PTEN and OCT4, have in fact been reported to be under the regulation of pseudogene-expressed asRNAs. Here, we review what are known about pseudogene expressed non-coding RNA mediated gene regulation and their roles in the control of epigenetic states. PMID:24842102

  18. The roles of histone modifications and small RNA in centromere function.

    PubMed

    Ekwall, Karl

    2004-01-01

    Here, epigenetic regulation of centromeric chromatin in fission yeast (Schizosaccharomyces pombe) is reviewed, focussing on the role of histone modifications and the link to RNA interference (RNAi). Fission yeast centromeres are organized into two structurally and functionally distinct domains, both of which are required for centromere function. The central core domain anchors the kinetochore structure while the flanking heterochromatin domain is important for sister centromere cohesion. The chromatin structure of both domains is regulated epigenetically. In the central core domain, the histone H3 variant Cnp1(CENP-A) plays a key role. In the flanking heterochromatin domain, histones are kept underacetylated by the histone deacetylases (HDACs) Clr3, Clr6 and Sir2, and methylated by Clr4 methyltransferase (HMTase) to create a specific binding site for the Swi6 protein. Swi6 then directly mediates cohesin binding to the centromeric heterochromatin. Recently, a surprising link was made between heterochromatin formation and RNAi. PMID:15289661

  19. [Functions of carboxyl-terminus of Hsc70 interacting protein and its role in neurodegenerative disease].

    PubMed

    Yan, Wei-qian; Wang, Jun-ling; Tang, Bei-sha

    2012-08-01

    Neurodegenerative diseases are a group of chronic progressive neuronal damage disorders. The cause is unclear, most of them share a same pathological hallmark with misfold proteins accumulating in neurons. Carboxyl-terminus of Hsc70 interacting protein (CHIP) is a dual functional molecule, which has a N terminal tetratrico peptide repeat (TPR) domain that interacts with Hsc/Hsp70 complex and Hsp90 enabling CHIP to modulate the aberrant protein folding; and a C terminal U-box ubiquitin ligase domain that binds to the 26S subunit of the proteasome involved in protein degradation via ubiqutin-proteasome system. CHIP protein mediates interactions between the chaperone system and the ubiquitin-proteasome system, and plays an important role in maintaining the protein homeostasis in cells. This article reviews the molecular characteristics and physiological functions of CHIP, and its role in cellular metabolism and discusses the relationship between CHIP dysfunction and neurodegenerative diseases. PMID:22875499

  20. Children's Teaching Skills: The Role of Theory of Mind and Executive Function

    ERIC Educational Resources Information Center

    Davis-Unger, Angela C.; Carlson, Stephanie M.

    2008-01-01

    Teaching others effectively may rely on knowledge about the mind as well as self-control processes. The goal of this investigation was to explore the role of theory of mind (ToM) and executive function (EF) in children's developing teaching skills. Children 3.5-5.5 years of age (N = 82) were asked to teach a confederate learner how to play a board…

  1. Incorporating Family Function into Chronic Pain Disability: The Role of Catastrophizing.

    PubMed

    Akbari, Fatemeh; Dehghani, Mohsen; Khatibi, Ali; Vervoort, Tine

    2016-01-01

    Background. Observers' responses to pain are recently investigated to more comprehensively explain chronic pain (CP) and disability. However, the role of family context, defined as interference in roles, communication, and problem-solving, and how (i.e., through which mechanisms) these variables contribute to CP related disability have yet to be examined. Objectives. The aim of the present study is to examine family context in relationship to pain catastrophizing, fear of movement, and depression and its role in understanding CP disability. Three different models were examined. Methods. A total sample of 142 patients with musculoskeletal chronic pain was recruited to examine the role of fear of movement, pain intensity, pain catastrophizing, and depression in relationship to family functioning as predictors of disability. Results. Findings indicated that two models showed acceptable fit, but one of them revealed superior fit indices. Results of the model with superior fit indices indicated that family dysfunction may contribute to catastrophic thinking, which, in turn, contributes to patients' disability through increasing fear of movement and depression. Discussion. The current study provides further support for the notion that the impact of emotional and cognitive variables upon CP-related disability can be better understood when we consider the social context of pain patients and family function in particular. PMID:27445620

  2. The Physiological Role of Arcuate Kisspeptin Neurons in the Control of Reproductive Function in Female Rats

    PubMed Central

    Beale, K.E.; Kinsey-Jones, J.S.; Gardiner, J.V.; Harrison, E.K.; Thompson, E.L.; Hu, M.H.; Sleeth, M.L.; Sam, A.H.; Greenwood, H.C.; McGavigan, A.K.; Dhillo, W.S.; Mora, J.M.; Li, X.F.; Franks, S.; Bloom, S.R.; O'Byrne, K.T.

    2014-01-01

    Kisspeptin plays a pivotal role in pubertal onset and reproductive function. In rodents, kisspeptin perikarya are located in 2 major populations: the anteroventral periventricular nucleus and the hypothalamic arcuate nucleus (ARC). These nuclei are believed to play functionally distinct roles in the control of reproduction. The anteroventral periventricular nucleus population is thought to be critical in the generation of the LH surge. However, the physiological role played by the ARC kisspeptin neurons remains to be fully elucidated. We used bilateral stereotactic injection of recombinant adeno-associated virus encoding kisspeptin antisense into the ARC of adult female rats to investigate the physiological role of kisspeptin neurons in this nucleus. Female rats with kisspeptin knockdown in the ARC displayed a significantly reduced number of both regular and complete oestrous cycles and significantly longer cycles over the 100-day period of the study. Further, kisspeptin knockdown in the ARC resulted in a decrease in LH pulse frequency. These data suggest that maintenance of ARC-kisspeptin levels is essential for normal pulsatile LH release and oestrous cyclicity. PMID:24424033

  3. Incorporating Family Function into Chronic Pain Disability: The Role of Catastrophizing

    PubMed Central

    Akbari, Fatemeh; Dehghani, Mohsen; Khatibi, Ali; Vervoort, Tine

    2016-01-01

    Background. Observers' responses to pain are recently investigated to more comprehensively explain chronic pain (CP) and disability. However, the role of family context, defined as interference in roles, communication, and problem-solving, and how (i.e., through which mechanisms) these variables contribute to CP related disability have yet to be examined. Objectives. The aim of the present study is to examine family context in relationship to pain catastrophizing, fear of movement, and depression and its role in understanding CP disability. Three different models were examined. Methods. A total sample of 142 patients with musculoskeletal chronic pain was recruited to examine the role of fear of movement, pain intensity, pain catastrophizing, and depression in relationship to family functioning as predictors of disability. Results. Findings indicated that two models showed acceptable fit, but one of them revealed superior fit indices. Results of the model with superior fit indices indicated that family dysfunction may contribute to catastrophic thinking, which, in turn, contributes to patients' disability through increasing fear of movement and depression. Discussion. The current study provides further support for the notion that the impact of emotional and cognitive variables upon CP-related disability can be better understood when we consider the social context of pain patients and family function in particular. PMID:27445620

  4. Mitochondrial Function, Biology, and Role in Disease: A Scientific Statement From the American Heart Association.

    PubMed

    Murphy, Elizabeth; Ardehali, Hossein; Balaban, Robert S; DiLisa, Fabio; Dorn, Gerald W; Kitsis, Richard N; Otsu, Kinya; Ping, Peipei; Rizzuto, Rosario; Sack, Michael N; Wallace, Douglas; Youle, Richard J

    2016-06-10

    Cardiovascular disease is a major leading cause of morbidity and mortality in the United States and elsewhere. Alterations in mitochondrial function are increasingly being recognized as a contributing factor in myocardial infarction and in patients presenting with cardiomyopathy. Recent understanding of the complex interaction of the mitochondria in regulating metabolism and cell death can provide novel insight and therapeutic targets. The purpose of this statement is to better define the potential role of mitochondria in the genesis of cardiovascular disease such as ischemia and heart failure. To accomplish this, we will define the key mitochondrial processes that play a role in cardiovascular disease that are potential targets for novel therapeutic interventions. This is an exciting time in mitochondrial research. The past decade has provided novel insight into the role of mitochondria function and their importance in complex diseases. This statement will define the key roles that mitochondria play in cardiovascular physiology and disease and provide insight into how mitochondrial defects can contribute to cardiovascular disease; it will also discuss potential biomarkers of mitochondrial disease and suggest potential novel therapeutic approaches. PMID:27126807

  5. Plant Functional Diversity Can Be Independent of Species Diversity: Observations Based on the Impact of 4-Yrs of Nitrogen and Phosphorus Additions in an Alpine Meadow

    PubMed Central

    Li, Wei; Cheng, Ji-Min; Yu, Kai-Liang; Epstein, Howard E.; Guo, Liang; Jing, Guang-Hua; Zhao, Jie; Du, Guo-Zhen

    2015-01-01

    Past studies have widely documented the decrease in species diversity in response to addition of nutrients, however functional diversity is often independent from species diversity. In this study, we conducted a field experiment to examine the effect of nitrogen and phosphorus fertilization ((NH4)2 HPO4) at 0, 15, 30 and 60 g m-2 yr-1 (F0, F15, F30 and F60) after 4 years of continuous fertilization on functional diversity and species diversity, and its relationship with productivity in an alpine meadow community on the Tibetan Plateau. To this purpose, three community-weighted mean trait values (specific leaf area, SLA; mature plant height, MPH; and seed size, SS) for 30 common species in each fertilization level were determined; three components of functional diversity (functional richness, FRic; functional evenness, FEve; and Rao’s index of quadratic entropy, FRao) were quantified. Our results showed that: (i) species diversity sharply decreased, but functional diversity remained stable with fertilization; (ii) community-weighted mean traits (SLA and MPH) had a significant increase along the fertilization level; (iii) aboveground biomass was not correlated with functional diversity, but it was significantly correlated with species diversity and MPH. Our results suggest that decreases in species diversity due to fertilization do not result in corresponding changes in functional diversity. Functional identity of species may be more important than functional diversity in influencing aboveground productivity in this alpine meadow community, and our results also support the mass ratio hypothesis; that is, the traits of the dominant species influenced the community biomass production. PMID:26295345

  6. Role of Survivin in cytokinesis revealed by a separation-of-function allele

    PubMed Central

    Szafer-Glusman, Edith; Fuller, Margaret T.; Giansanti, Maria Grazia

    2011-01-01

    The chromosomal passenger complex (CPC), containing Aurora B kinase, Inner Centromere Protein, Survivin, and Borealin, regulates chromosome condensation and interaction between kinetochores and microtubules at metaphase, then relocalizes to midzone microtubules at anaphase and regulates central spindle organization and cytokinesis. However, the precise role(s) played by the CPC in anaphase have been obscured by its prior functions in metaphase. Here we identify a missense allele of Drosophila Survivin that allows CPC localization and function during metaphase but not cytokinesis. Analysis of mutant cells showed that Survivin is essential to target the CPC and the mitotic kinesin-like protein 1 orthologue Pavarotti (Pav) to the central spindle and equatorial cell cortex during anaphase in both larval neuroblasts and spermatocytes. Survivin also enabled localization of Polo kinase and Rho at the equatorial cortex in spermatocytes, critical for contractile ring assembly. In neuroblasts, in contrast, Survivin function was not required for localization of Rho, Polo, or Myosin II to a broad equatorial cortical band but was required for Myosin II to transition to a compact, fully constricted ring. Analysis of this “separation-of-function” allele demonstrates the direct role of Survivin and the CPC in cytokinesis and highlights striking differences in regulation of cytokinesis in different cell systems. PMID:21865602

  7. Addition of surfactants in ozonated water cleaning for the suppression of functional group formation and particle adhesion on the SiO2 surface

    NASA Astrophysics Data System (ADS)

    Yang, Jahyun; Im, Kyungtaek; Lim, Sangwoo

    2011-04-01

    Various kinds of surfactants were added to a cleaning solution and deionized (DI) water, and their effect on the suppression of organic function group formation and particle adhesion to a SiO2 surface was analyzed using multi-internal reflection Fourier transform infrared spectroscopy. The results implied that attached organic functional groups are affected by the chemical structure of a surfactant in DI water. Furthermore, the addition of anionic glycolic acid ethoxylate 4-tert-butylphenyl ether (GAE4E) is the most effective in terms of preventing organic group attachment and particle adhesion to the SiO2 surface, whether it was added to the cleaning solution or post-cleaning rinse water, with or without polystyrene latex particles. Moreover, it was possible to completely prevent particle adhesion to the SiO2 surface with the proper addition of GAE4E in DIO3 solution.

  8. Role of Protein Phosphorylation and Tyrosine Phosphatases in the Adrenal Regulation of Steroid Synthesis and Mitochondrial Function.

    PubMed

    Paz, Cristina; Cornejo Maciel, Fabiana; Gorostizaga, Alejandra; Castillo, Ana F; Mori Sequeiros García, M Mercedes; Maloberti, Paula M; Orlando, Ulises D; Mele, Pablo G; Poderoso, Cecilia; Podesta, Ernesto J

    2016-01-01

    In adrenocortical cells, adrenocorticotropin (ACTH) promotes the activation of several protein kinases. The action of these kinases is linked to steroid production, mainly through steroidogenic acute regulatory protein (StAR), whose expression and activity are dependent on protein phosphorylation events at genomic and non-genomic levels. Hormone-dependent mitochondrial dynamics and cell proliferation are functions also associated with protein kinases. On the other hand, protein tyrosine dephosphorylation is an additional component of the ACTH signaling pathway, which involves the "classical" protein tyrosine phosphatases (PTPs), such as Src homology domain (SH) 2-containing PTP (SHP2c), and members of the MAP kinase phosphatase (MKP) family, such as MKP-1. PTPs are rapidly activated by posttranslational mechanisms and participate in hormone-stimulated steroid production. In this process, the SHP2 tyrosine phosphatase plays a crucial role in a mechanism that includes an acyl-CoA synthetase-4 (Acsl4), arachidonic acid (AA) release and StAR induction. In contrast, MKPs in steroidogenic cells have a role in the turn-off of the hormonal signal in ERK-dependent processes such as steroid synthesis and, perhaps, cell proliferation. This review analyzes the participation of these tyrosine phosphates in the ACTH signaling pathway and the action of kinases and phosphatases in the regulation of mitochondrial dynamics and steroid production. In addition, the participation of kinases and phosphatases in the signal cascade triggered by different stimuli in other steroidogenic tissues is also compared to adrenocortical cell/ACTH and discussed. PMID:27375556

  9. Contrasting soil fungal community responses to experimental nitrogen addition using the large subunit rRNA taxonomic marker and cellobiohydrolase I functional marker.

    PubMed

    Mueller, Rebecca C; Balasch, Monica M; Kuske, Cheryl R

    2014-09-01

    Human activities have resulted in increased nitrogen inputs into terrestrial ecosystems, but the impact of nitrogen on ecosystem function, such as nutrient cycling, will depend at least in part on the response of soil fungal communities. We examined the response of soil fungi to experimental nitrogen addition in a loblolly pine forest (North Carolina, USA) using a taxonomic marker (large subunit rDNA, LSU) and a functional marker involved in a critical step of cellulose degradation (cellobiohydrolase, cbhI) at five time points that spanned fourteen months. Sampling date had no impact on fungal community richness or composition for either gene. Based on the LSU, nitrogen addition led to increased fungal community richness, reduced relative abundance of fungi in the phylum Basidiomycota and altered community composition; however, similar shifts were not observed with cbhI. Fungal community dissimilarity of the LSU and cbhI genes was significantly correlated in the ambient plots, but not in nitrogen-amended plots, suggesting either functional redundancy of fungi with the cbhI gene or shifts in other functional groups in response to nitrogen addition. To determine whether sequence similarity of cbhI could be predicted based on taxonomic relatedness of fungi, we conducted a phylogenetic analysis of publically available cbhI sequences from known isolates and found that for a subset of isolates, similar cbhI genes were found within distantly related fungal taxa. Together, these findings suggest that taxonomic shifts in the total fungal community do not necessarily result in changes in the functional diversity of fungi. PMID:25039479

  10. Role of the XPA protein in the NER pathway: A perspective on the function of structural disorder in macromolecular assembly.

    PubMed

    Fadda, Elisa

    2016-01-01

    Lack of structure is often an essential functional feature of protein domains. The coordination of macromolecular assemblies in DNA repair pathways is yet another task disordered protein regions are highly implicated in. Here I review the available experimental and computational data and within this context discuss the functional role of structure and disorder in one of the essential scaffolding proteins in the nucleotide excision repair (NER) pathway, namely Xeroderma pigmentosum complementation group A (XPA). From the analysis of the current knowledge, in addition to protein-protein docking and secondary structure prediction results presented for the first time herein, a mechanistic framework emerges, where XPA builds the NER pre-incision complex in a modular fashion, as "beads on a string", where the protein-protein interaction "beads", or modules, are interconnected by disordered link regions. This architecture is ideal to avoid the expected steric hindrance constraints of the DNA expanded bubble. Finally, the role of the XPA structural disorder in binding affinity modulation and in the sequential binding of NER core factors in the pre-incision complex is also discussed. PMID:26865925

  11. An Essential Role for Cdc42 in the Functioning of the Adult Mammary Gland.

    PubMed

    Druso, Joseph E; Endo, Makoto; Lin, Miao-Chong Joy; Peng, Xu; Antonyak, Marc A; Meller, Stephanie; Cerione, Richard A

    2016-04-22

    The Rho family small GTPase Cdc42 has been implicated in a wide range of cellular functions including the establishment of cell polarity and the remodeling of the actin cytoskeletal architecture, resulting in the tight regulation of cell growth and survival during developmental processes. The complete knock-out of Cdc42 in the mouse is embryonic-lethal, and its targeted deletion in various tissues has been shown to disrupt tissue homeostasis. Thus far, in most studies, the targeted deletion of Cdc42 occurred during embryogenesis. Here, we have used a conditional gene deletion strategy in mice to probe the specific role of Cdc42 during adult mammary gland function. Cdc42 conditional-knock-out females were unable to adequately nourish their pups, due to a disorganized epithelial compartment within their mammary glands. A closer examination showed that their mammary epithelial cells were not able to maintain functional alveolar lumens, due to an inability to establish normal apical/basal epithelial polarity, as well as proper cell-cell contacts. Loss of these essential epithelial characteristics led to a premature sloughing off of the Cdc42-null epithelial cells. Overall our findings demonstrate that Cdc42 plays essential roles in mammary gland function post pregnancy, where it helps to establish proper epithelial cell polarity and tissue homeostasis during lactation. PMID:26912661

  12. Functional roles of flavonoids in photoprotection: new evidence, lessons from the past.

    PubMed

    Agati, Giovanni; Brunetti, Cecilia; Di Ferdinando, Martina; Ferrini, Francesco; Pollastri, Susanna; Tattini, Massimiliano

    2013-11-01

    We discuss on the relative significance of different functional roles potentially served by flavonoids in photoprotection, with special emphasis to their ability to scavenge reactive oxygen species (ROS) and control the development of individual organs and whole plant. We propose a model in which chloroplast-located flavonoids scavenge H2O2 and singlet oxygen generated under excess light-stress, thus avoiding programmed cell death. We also draw a picture in which vacuolar flavonoids in conjunction with peroxidases and ascorbic acid constitute a secondary antioxidant system aimed at detoxifying H2O2, which may diffuse out of the chloroplast at considerable rates and enter the vacuole following excess light stress-induced depletion of ascorbate peroxidase. We hypothesize for flavonols key roles as developmental regulators in early and current-day land-plants, based on their ability to modulate auxin movement and auxin catabolism. We show that antioxidant flavonoids display the greatest capacity to regulate key steps of cell growth and differentiation in eukaryotes. These regulatory functions of flavonoids, which are shared by plants and animals, are fully accomplished in the nM concentration range, as likely occurred in early land plants. We therefore conclude that functions of flavonoids as antioxidants and/or developmental regulators flavonoids are of great value in photoprotection. We also suggest that UV-B screening was just one of the multiple functions served by flavonoids when early land-plants faced an abrupt increase in sunlight irradiance. PMID:23583204

  13. Fundamental studies and development of nickel-catalyzed trifluoromethylthiolation of aryl chlorides: active catalytic species and key roles of ligand and traceless MeCN additive revealed.

    PubMed

    Yin, Guoyin; Kalvet, Indrek; Englert, Ulli; Schoenebeck, Franziska

    2015-04-01

    A catalytic protocol to convert aryl and heteroaryl chlorides to the corresponding trifluoromethyl sulfides is reported herein. It relies on a relatively inexpensive Ni(cod)2/dppf (cod = 1,5-cyclooctadiene; dppf = 1,1'-bis(diphenylphosphino)ferrocene) catalyst system and the readily accessible coupling reagent (Me4N)SCF3. Our computational and experimental mechanistic data are consistent with a Ni(0)/Ni(II) cycle and inconsistent with Ni(I) as the reactive species. The relevant intermediates were prepared, characterized by X-ray crystallography, and tested for their catalytic competence. This revealed that a monomeric tricoordinate Ni(I) complex is favored for dppf and Cl whose role was unambiguously assigned as being an off-cycle catalyst deactivation product. Only bidentate ligands with wide bite angles (e.g., dppf) are effective. These bulky ligands render the catalyst resting state as [(P-P)Ni(cod)]. The latter is more reactive than Ni(P-P)2, which was found to be the resting state for ligands with smaller bite angles and suffers from an initial high-energy dissociation of one ligand prior to oxidative addition, rendering the system unreactive. The key to effective catalysis is hence the presence of a labile auxiliary ligand in the catalyst resting state. For more challenging substrates, high conversions were achieved via the employment of MeCN as a traceless additive. Mechanistic data suggest that its beneficial role lies in decreasing the energetic span, therefore accelerating product formation. Finally, the methodology has been applied to synthetic targets of pharmaceutical relevance. PMID:25790253

  14. Pancreatic and Islet Development and Function: The Role of Thyroid Hormone

    PubMed Central

    Mastracci, Teresa L; Evans-Molina, Carmella

    2014-01-01

    A gradually expanding body of literature suggests that Thyroid Hormone (TH) and Thyroid Hormone Receptors (TRs) play a contributing role in pancreatic and islet cell development, maturation, and function. Studies using a variety of model systems capable of exploiting species-specific developmental paradigms have revealed the contribution of TH to cellular differentiation, lineage decisions, and endocrine cell specification. Moreover, in vitro and in vivo evidence suggests that TH is involved in islet β cell proliferation and maturation; however, the signaling pathway(s) connected with this function of TH/TR are not well understood. The purpose of this review is to discuss the current literature that has defined the effects of TH and TRs on pancreatic and islet cell development and function, describe the impact of hyper- and hypothyroidism on whole body metabolism, and highlight future and potential applications of TH in novel therapeutic strategies for diabetes. PMID:25506600

  15. Key role in ecosystem functioning of scavengers reliant on a single common species

    PubMed Central

    Inger, Richard; Per, Esra; Cox, Daniel T.C.; Gaston, Kevin J.

    2016-01-01

    The importance of species richness in maintaining ecosystem function in the field remains unclear. Recent studies however have suggested that in some systems functionality is maintained by a few abundant species. Here we determine this relationship by quantifying the species responsible for a key ecosystem role, carcass removal by scavengers. We find that, unlike those within largely unaltered environments, the scavenger community within our highly altered system is dominated by a single species, the Carrion crow, despite the presence of a number of other scavenging species. Furthermore, we find no relationship between abundance of crows and carcass removal. However, the overall activity of crows predicts carcass biomass removal rate in an asymptotic manner, suggesting that a relatively low level of abundance and scavenging activity is required to maintain this component of ecosystem function. PMID:27404915

  16. Key role in ecosystem functioning of scavengers reliant on a single common species.

    PubMed

    Inger, Richard; Per, Esra; Cox, Daniel T C; Gaston, Kevin J

    2016-01-01

    The importance of species richness in maintaining ecosystem function in the field remains unclear. Recent studies however have suggested that in some systems functionality is maintained by a few abundant species. Here we determine this relationship by quantifying the species responsible for a key ecosystem role, carcass removal by scavengers. We find that, unlike those within largely unaltered environments, the scavenger community within our highly altered system is dominated by a single species, the Carrion crow, despite the presence of a number of other scavenging species. Furthermore, we find no relationship between abundance of crows and carcass removal. However, the overall activity of crows predicts carcass biomass removal rate in an asymptotic manner, suggesting that a relatively low level of abundance and scavenging activity is required to maintain this component of ecosystem function. PMID:27404915

  17. Continental cichlid radiations: functional diversity reveals the role of changing ecological opportunity in the Neotropics.

    PubMed

    Arbour, Jessica Hilary; López-Fernández, Hernán

    2016-08-17

    Adaptive radiations have been hypothesized to contribute broadly to the diversity of organisms. Models of adaptive radiation predict that ecological opportunity and ecological release, the availability of empty ecological niches and the response by adapting lineages to occupy them, respectively, drive patterns of phenotypic and lineage diversification. Adaptive radiations driven by 'ecological opportunity' are well established in island systems; it is less clear if ecological opportunity influences continent-wide diversification. We use Neotropical cichlid fishes to test if variation in rates of functional evolution is consistent with changing ecological opportunity. Across a functional morphological axis associated with ram-suction feeding traits, evolutionary rates declined through time as lineages diversified in South America. Evolutionary rates of ram-suction functional morphology also appear to have accelerated as cichlids colonized Central America and encountered renewed opportunity. Our results suggest that ecological opportunity may play an important role in shaping patterns of morphological diversity of even broadly distributed lineages like Neotropical cichlids. PMID:27512144

  18. Role of Positive Selection in Functional Divergence of Mammalian Neuronal Apoptosis Inhibitor Proteins during Evolution

    PubMed Central

    Kong, Fanzhi; Su, Zhaoliang; Zhou, Chenglin; Sun, Caixia; Liu, Yanfang; Zheng, Dong; Yuan, Hongyan; Yin, Jingping; Fang, Jie; Wang, Shengjun; Xu, Huaxi

    2011-01-01

    Neuronal apoptosis inhibitor proteins (NAIPs) are members of Nod-like receptor (NLR) protein family. Recent research demostrated that some NAIP genes were strongly associated with both innate immunity and many inflammatory diseases in humans. However, no similar phenomena have been reported in other mammals. Furthermore, some NAIP genes have undergone pseudogenization or have been lost during the evolution of some higher mammals. We therefore aimed to determine if functional divergence had occurred, and if natural selection had played an important role in the evolution of these genes. The results showed that NAIP genes have undergone pseudogenization and functional divergence, driven by positive selection. Positive selection has also influenced NAIP protein structure, resulting in further functional divergence. PMID:22131819

  19. Functional role of voltage gated Ca2+ channels in heart automaticity

    PubMed Central

    Mesirca, Pietro; Torrente, Angelo G.; Mangoni, Matteo E.

    2015-01-01

    Pacemaker activity of automatic cardiac myocytes controls the heartbeat in everyday life. Cardiac automaticity is under the control of several neurotransmitters and hormones and is constantly regulated by the autonomic nervous system to match the physiological needs of the organism. Several classes of ion channels and proteins involved in intracellular Ca2+ dynamics contribute to pacemaker activity. The functional role of voltage-gated calcium channels (VGCCs) in heart automaticity and impulse conduction has been matter of debate for 30 years. However, growing evidence shows that VGCCs are important regulators of the pacemaker mechanisms and play also a major role in atrio-ventricular impulse conduction. Incidentally, studies performed in genetically modified mice lacking L-type Cav1.3 (Cav1.3−/−) or T-type Cav3.1 (Cav3.1−/−) channels show that genetic inactivation of these channels strongly impacts pacemaking. In cardiac pacemaker cells, VGCCs activate at negative voltages at the beginning of the diastolic depolarization and importantly contribute to this phase by supplying inward current. Loss-of-function of these channels also impairs atrio-ventricular conduction. Furthermore, inactivation of Cav1.3 channels promotes also atrial fibrillation and flutter in knockout mice suggesting that these channels can play a role in stabilizing atrial rhythm. Genomic analysis demonstrated that Cav1.3 and Cav3.1 channels are widely expressed in pacemaker tissue of mice, rabbits and humans. Importantly, human diseases of pacemaker activity such as congenital bradycardia and heart block have been attributed to loss-of-function of Cav1.3 and Cav3.1 channels. In this article, we will review the current knowledge on the role of VGCCs in the generation and regulation of heart rate and rhythm. We will discuss also how loss of Ca2+ entry through VGCCs could influence intracellular Ca2+ handling and promote atrial arrhythmias. PMID:25698974

  20. Resveratrol attenuated estrogen-deficient-induced cardiac dysfunction: role of AMPK, SIRT1, and mitochondrial function

    PubMed Central

    Meng, Zijun; Jing, Hongjiang; Gan, Lu; Li, Hua; Luo, Bingde

    2016-01-01

    Large epidemiological studies suggest that there are important differences in the incidence and severity of a wide variety of cardiac diseases, between premenopausal and menopausal women. Recently, it has been demonstrated that resveratrol may has similar function as estrogen. However, whether resveratrol replacement could mimic estrogen to protect heart in ovariectomized mice remains completely unknown. Firstly, the present study has used OVX/CAL model to investigate the effect of RSV on ischemic heart. Echocardiography analysis revealed that RSV administration significantly improved cardiac contractile function in estrogen-deficient mice. RSV also significantly reduced CK and LDH release, and heart infarct size in OVX/CAL group. Secondly, mitochondrial functions, including MRC activities, MDA level, and mitochondrial swelling, were evaluated in OVX mice. It was found that supplementation with RSV could restore mitochondrial function dampened by OVX. Thirdly, these protective functions mediated by RSV were mainly attributed to the enhancement of SIRT1/AMPK activity. In summary, the results support a potential role of resveratrol in the protection of cardiac functions under estrogen depletion status. PMID:27398147

  1. Family socioeconomic status and child executive functions: the roles of language, home environment, and single parenthood.

    PubMed

    Sarsour, Khaled; Sheridan, Margaret; Jutte, Douglas; Nuru-Jeter, Amani; Hinshaw, Stephen; Boyce, W Thomas

    2011-01-01

    The association between family socioeconomic status (SES) and child executive functions is well-documented. However, few studies have examined the role of potential mediators and moderators. We studied the independent and interactive associations between family SES and single parenthood to predict child executive functions of inhibitory control, cognitive flexibility, and working memory and examined child expressive language abilities and family home environment as potential mediators of these associations. Sixty families from diverse SES backgrounds with a school-age target child (mean [SD] age = 9.9 [0.96] years) were evaluated. Child executive functioning was measured using a brief battery. The quality of the home environment was evaluated using the Home Observation for the Measurement of the Environment inventory. Family SES predicted the three child executive functions under study. Single parent and family SES were interactively associated with children's inhibitory control and cognitive flexibility; such that children from low SES families who were living with one parent performed less well on executive function tests than children from similarly low SES who were living with two parents. Parental responsivity, enrichment activities and family companionship mediated the association between family SES and child inhibitory control and working memory. This study demonstrates that family SES inequalities are associated with inequalities in home environments and with inequalities in child executive functions. The impact of these disparities as they unfold in the lives of typically developing children merits further investigation and understanding. PMID:21073770

  2. Functional role of mucosal-associated invariant T cells in HIV infection.

    PubMed

    Saeidi, Alireza; Ellegård, Rada; Yong, Yean K; Tan, Hong Y; Velu, Vijayakumar; Ussher, James E; Larsson, Marie; Shankar, Esaki M

    2016-08-01

    MAIT cells represent an evolutionarily conserved, MR1-restricted, innate-like cell subset that express high levels of CD161; have a canonical semi-invariant TCR iVα7.2; and may have an important role in mucosal immunity against various bacterial and fungal pathogens. Mature MAIT cells are CD161(hi)PLZF(hi)IL-18Rα(+)iVα7.2(+)γδ-CD3(+)CD8(+) T cells and occur in the peripheral blood, liver, and mucosa of humans. MAIT cells are activated by a metabolic precursor of riboflavin synthesis presented by MR1 and, therefore, respond to many bacteria and some fungi. Despite their broad antibacterial properties, their functional role in persistent viral infections is poorly understood. Although there is an increasing line of evidence portraying the depletion of MAIT cells in HIV disease, the magnitude and the potential mechanisms underlying such depletion remain unclear. Recent studies suggest that MAIT cells are vulnerable to immune exhaustion as a consequence of HIV and hepatitis C virus infections and HIV/tuberculosis coinfections. HIV infection also appears to cause functional depletion of MAIT cells resulting from abnormal expression of T-bet and EOMES, and effective ART is unable to completely salvage functional MAIT cell loss. Depletion and exhaustion of peripheral MAIT cells may affect mucosal immunity and could increase susceptibility to opportunistic infections during HIV infection. Here, we review some of the important mechanisms associated with depletion and functional loss of MAIT cells and also suggest potential immunotherapeutic strategies to restore MAIT cell functions, including the use of IL-7 to restore effector functions in HIV disease. PMID:27256572

  3. The role of 5-alpha reductase inhibitors in prostate pathophysiology: Is there an additional advantage to inhibition of type 1 isoenzyme?

    PubMed

    Goldenberg, Larry; So, Alan; Fleshner, Neil; Rendon, Ricardo; Drachenberg, Darrel; Elhilali, Mostafa

    2009-06-01

    Normal growth and function of the prostate are contingent on the reduction of testosterone to dihydrotestosterone (DHT) by 5-alpha reductase (5-AR) enzymes types 1 and 2. It has been theorized that an overabundance of DHT may be implicated in the pathogenesis of both benign prostatic hyperplasia (BPH) and prostate cancer. Inhibitors of 5-AR such as dutasteride and finasteride may therefore have an important role in the prevention and treatment of BPH and prostate cancer. Dutasteride provides greater suppression of DHT than finasteride, thereby underlying the hypothesis that inhibition of both type 1 and type 2 would provide correspondingly greater protection than inhibition of type 2 alone. We review the potential significance of the 5-AR inhibitors in reducing the risk of prostate cancer according to the basic biology of prostate disease. PMID:19543428

  4. Functionalized quantum dots induce proinflammatory responses in vitro: the role of terminal functional group-associated endocytic pathways

    NASA Astrophysics Data System (ADS)

    Zhang, Yijuan; Pan, Hong; Zhang, Pengfei; Gao, Ningning; Lin, Yi; Luo, Zichao; Li, Ping; Wang, Ce; Liu, Lanlan; Pang, Daiwen; Cai, Lintao; Ma, Yifan

    2013-06-01

    PEGylation has been applied as an effective strategy of surface functionalization to improve the stability and reduce non-specific binding of quantum dots (QDs). However, its effects on the proinflammatory properties of QDs and the underlying mechanism have not been well elucidated yet. Herein, the proinflammatory effects of PEGylated CdSe/ZnS QDs with an amphiphilic polymer coating (PEG-pQDs) were investigated in human pulmonary epithelial cells and macrophages by evaluating the cytokine/chemokine production. The results showed that the proinflammatory effects of PEG-pQDs were strongly associated with the functional groups (-COOH, -NH2, -OH, and -OCH3) at the end of PEG chain. COOH-PEG-pQDs demonstrated the most proinflammatory effects followed by NH2-PEG-pQDs and HO-PEG-pQDs with CH3O-PEG-pQDs exhibiting the least proinflammatory effects. The proinflammatory effects of PEG-pQDs relied on lipid raft- and class A scavenger receptor (SRA)-dependent endocytic pathways as well as the downstream NF-κB and MAPK signaling cascades. COOH-PEG-pQDs were selectively internalized by lipid raft- and SRA-mediated endocytosis, which consequently activated NF-κB signaling pathway. On the other hand, NH2-PEG-pQDs and HO-PEG-pQDs were mostly internalized via lipid raft-mediated endocytosis, thereby activating p38 MAPK/AP-1 signaling cascades. These data revealed a critical role of terminal functional group-associated endocytic pathways in the proinflammatory responses induced by PEGylated QDs in human pulmonary epithelial cells and macrophages.PEGylation has been applied as an effective strategy of surface functionalization to improve the stability and reduce non-specific binding of quantum dots (QDs). However, its effects on the proinflammatory properties of QDs and the underlying mechanism have not been well elucidated yet. Herein, the proinflammatory effects of PEGylated CdSe/ZnS QDs with an amphiphilic polymer coating (PEG-pQDs) were investigated in human pulmonary epithelial

  5. Distinct Roles of Apolipoproteins A1 and E in the Modulation of High-Density Lipoprotein Composition and Function.

    PubMed

    Filou, Serafoula; Lhomme, Marie; Karavia, Eleni A; Kalogeropoulou, Christina; Theodoropoulos, Vassilis; Zvintzou, Evangelia; Sakellaropoulos, George C; Petropoulou, Peristera-Ioanna; Constantinou, Caterina; Kontush, Anatol; Kypreos, Kyriakos E

    2016-07-12

    In addition to high-density lipoprotein cholesterol (HDL-C) levels, HDL quality also appears to be very important for atheroprotection. Analysis of various clinical paradigms suggests that the lipid and apolipoprotein composition of HDL defines its size, shape, and functions and may determine its beneficial effects on human health. Previously, we reported that like apolipoprotein A-I (Apoa1), apolipoprotein E (Apoe) is also capable of promoting the de novo biogenesis of HDL with the participation of ATP binding cassette A lipid transporter member 1 (Abca1) and plasma enzyme lecithin:cholesterol acyltransferase (Lcat), in a manner independent of a functional Apoa1. Here, we performed a comparative analysis of the functions of these HDL subpopulations. Specifically, Apoe and Apoa1 double-deficient (Apoe(-/-) × Apoa1(-/-)) mice were infected with APOA1- or APOE3-expressing adenoviruses, and APOA1-containing HDL (APOA1-HDL) and APOE3-containing HDL (APOE3-HDL), respectively, were isolated and analyzed by biochemical and physicochemical methods. Western blot and lipidomic analyses indicated significant differences in the apolipoprotein and lipid composition of the two HDL species. Moreover APOE3-HDL presented a markedly reduced antioxidant potential and Abcg1-mediated cholesterol efflux capacity. Surprisingly, APOE3-HDL but not APOA1-HDL attenuated LPS-induced production of TNFα in RAW264.7 cells, suggesting that the anti-inflammatory effects of APOA1 are dependent on APOE expression. Taken together, our data indicate that APOA1 and APOE3 recruit different apolipoproteins and lipids on the HDL particle, leading to structurally and functionally distinct HDL subpopulations. The distinct role of these two apolipoproteins in the modulation of HDL functionality may pave the way toward the development of novel pharmaceuticals that aim to improve HDL functionality. PMID:27332083

  6. Food additives

    MedlinePlus

    Food additives are substances that become part of a food product when they are added during the processing or making of that food. "Direct" food additives are often added during processing to: Add nutrients ...

  7. Functional role of a protein foldon--an Omega-loop foldon controls the alkaline transition in ferricytochrome c.

    PubMed

    Maity, Haripada; Rumbley, Jon N; Englander, S Walter

    2006-05-01

    Hydrogen exchange results for cytochrome c and several other proteins show that they are composed of a number of foldon units which continually unfold and refold and account for some functional properties. Previous work showed that one Omega-loop foldon controls the rate of the structural switching and ligand exchange behavior of cytochrome c known as the alkaline transition. The present work tests the role of foldons in the alkaline transition equilibrium. We measured the effects of denaturant and 14 destabilizing mutations. The results show that the ligand exchange equilibrium is controlled by the stability of the same foldon unit implicated before. In addition, the results obtained confirm the epsilon-amino group of Lys79 and Lys73 as the alkaline replacement ligands and bear on the search for a triggering group. PMID:16287119

  8. Rheological behavior of clay-nanoparticle hybrid-added bentonite suspensions: specific role of hybrid additives on the gelation of clay-based fluids.

    PubMed

    Jung, Youngsoo; Son, You-Hwan; Lee, Jung-Kun; Phuoc, Tran X; Soong, Yee; Chyu, Minking K

    2011-09-01

    Two different types of clay nanoparticle hybrid, iron oxide nanoparticle clay hybrid (ICH) and Al(2)O(3)-SiO(2) nanoparticle clay hybrid (ASCH), were synthesized and their effects on the rheological properties of aqueous bentonite fluids in steady state and dynamic state were explored. When ICH particles were added, bentonite particles in the fluid cross-link to form relatively well-oriented porous structure. This is attributed to the development of positively charged edge surfaces in ICH that leads to strengthening of the gel structure of the bentonite susensions. The role of ASCH particles on the interparticle association of the bentonite fluids is different from that of ICH and sensitive to pH. As pH of ASCH-added bentonite suspensions increased, the viscosity, yield stress, storage modulus, and flow stress decreased. In contrast, at low pH, the clay suspensions containing ASCH additives were coagulated and their rheological properties become close to those of ICH added bentonite fluids. A correlation between the net surface charge of the hybrid additives and the rheological properties of the fluids indicates that the embedded nanoparticles within the interlayer space control the variable charge of the edge surfaces of the platelets and determine the particles association behavior of the clay fluids. PMID:21888313

  9. Palladium-mediated borylation of pentafluorosulfanyl functionalized compounds: the crucial role of metal fluorido complexes.

    PubMed

    Berg, Claudia; Braun, Thomas; Laubenstein, Reik; Braun, Beatrice

    2016-03-11

    Stoichiometric reactions of SF5 functionalized bromo or iodo aromatics at [Pd(PiPr3)2] (1) led to the oxidative addition products 3, 5 and 7. They were converted into their corresponding palladium fluorido complexes, which reacted readily with bis(pinacolato)diboron (B2pin2) to give the borylated SF5 aromatic compounds. Based on these studies a catalytic borylation of SF5 organyls was developed. PMID:26872070

  10. Nonlinear responses to nitrogen and strong interactions with nitrogen and phosphorus additions drastically alter the structure and function of a high arctic ecosystem

    NASA Astrophysics Data System (ADS)

    Arens, Seth J. T.; Sullivan, Patrick F.; Welker, Jeffrey M.

    2008-09-01

    Significant changes in ecosystem CO2 exchange and vegetation characteristics were observed following multiple additions of nitrogen (N) and factorial additions of N and phosphorus (P) to prostrate dwarf-shrub, herb tundra in Northwest Greenland. Ecosystem CO2 exchange and vegetation cover and composition were very sensitive to low rates of N inputs (0.5 g m-2 y-1), indicating that even low rates of atmospheric N deposition may alter high arctic ecosystem structure and function. Increasing N addition from 1 to 5 g N m-2 y-1 did not alter CO2 exchange or vegetation characteristics, suggesting the ecosystem had become N saturated. Factorial additions of both N and P released the ecosystem from N saturation and dramatically increased gross ecosystem photosynthesis (+500%) and ecosystem respiration (+250%), such that the ecosystem switched from a small source of CO2 to a small sink for CO2 at midday during the 2005 growing season. Changes in the component fluxes of CO2 exchange were largely explained by a doubling of the normalized difference vegetation index, a 100% increase in vascular plant cover and dramatic increases in the abundance of several previously rare grass species. Our results clearly demonstrate that high arctic prostrate dwarf-shrub, herb tundra is highly sensitive to low levels of N addition and that future increases in N deposition or N mineralization will likely lead to change in carbon cycling and vegetation characteristics, but the magnitude of the response will be constrained by P availability.

  11. Purinergic glio-endothelial coupling during neuronal activity: role of P2Y1 receptors and eNOS in functional hyperemia in the mouse somatosensory cortex.

    PubMed

    Toth, Peter; Tarantini, Stefano; Davila, Antonio; Valcarcel-Ares, M Noa; Tucsek, Zsuzsanna; Varamini, Behzad; Ballabh, Praveen; Sonntag, William E; Baur, Joseph A; Csiszar, Anna; Ungvari, Zoltan

    2015-12-01

    Impairment of moment-to-moment adjustment of cerebral blood flow (CBF) via neurovascular coupling is thought to play a critical role in the genesis of cognitive impairment associated with aging and pathological conditions associated with accelerated cerebromicrovascular aging (e.g., hypertension, obesity). Although previous studies demonstrate that endothelial dysfunction plays a critical role in neurovascular uncoupling in these conditions, the role of endothelial NO mediation in neurovascular coupling responses is not well understood. To establish the link between endothelial function and functional hyperemia, neurovascular coupling responses were studied in mutant mice overexpressing or deficient in endothelial NO synthase (eNOS), and the role of P2Y1 receptors in purinergic glioendothelial coupling was assessed. We found that genetic depletion of eNOS (eNOS(-/-)) and pharmacological inhibition of NO synthesis significantly decreased the CBF responses in the somatosensory cortex evoked by whisker stimulation and by administration of ATP. Overexpression of eNOS enhanced NO mediation of functional hyperemia. In control mice, the selective and potent P2Y1 receptor antagonist MRS2179 attenuated both whisker stimulation-induced and ATP-mediated CBF responses, whereas, in eNOS(-/-) mice, the inhibitory effects of MRS2179 were blunted. Collectively, our findings provide additional evidence for purinergic glio-endothelial coupling during neuronal activity, highlighting the role of ATP-mediated activation of eNOS via P2Y1 receptors in functional hyperemia. PMID:26453330

  12. [Role and function of public health nurses in Taiwan: review of current status and future perspectives].

    PubMed

    Yeh, Yen-Po

    2014-06-01

    Public health nursing is a core practice of primary health care. Public health nurses (PHNs) in Taiwan act both as individual/family-based primary care providers and as population-based community care providers. Previous studies in Western countries have shown the role preference of PHNs to be highly influenced by the structure of the healthcare system, policies and major programs, and health insurance reimbursement mechanisms. Thus, the impact of the health transition and related changes in the abovementioned systems should be taken into consideration when adjusting the roles and functions of PHNs. The rising prevalence of chronic diseases and the multiple burdens caused by diseases is making healthcare delivery increasingly complicated. With PHNs no longer able to provide "catch-all" services due to manpower shortages, several potential specialty areas have opened up to participation and development by community nursing. These include psychiatric care, long-term care and palliative care, school/workplace health promotion, and disease management in hospitals. It will be essential that community nurses bridge the gap in service left by PHNs so that PHNs may refocus their job role on the health needs of the community as a whole. PHNs should continue to build partnerships with primary care settings and perform the key functions of demonstration, support, collaboration, service, and surveillance in the community. PMID:24899553

  13. New insights into the role of connexins in pancreatic islet function and diabetes

    PubMed Central

    Farnsworth, Nikki L.; Benninger, Richard K.P.

    2014-01-01

    Multi-cellular systems require complex signaling mechanisms for proper tissue function, to mediate signaling between cells in close proximity and at distances. This holds true for the islets of Langerhans, which are multicellular micro-organs located in the pancreas responsible for glycemic control, through secretion of insulin and other hormones. Coupling of electrical and metabolic signaling between islet β-cells is required for proper insulin secretion and effective glycemic control. β-cell specific coupling is established through gap junctions composed of connexin36, which results in coordinated insulin release across the islet. Islet connexins have been implicated in both Type-1 and Type-2 diabetes; however a clear link remains to be determined. The goal of this review is to discuss recent discoveries regarding the role of connexins in regulating insulin secretion, the regulation of connexins within the islet, and recent studies which support a role for connexins in diabetes. Further studies which investigate the regulation of connexins in the islet and their role in diabetes may lead to novel diabetes therapies which regulate islet function and β-cell survival through modulation of gap junction coupling. PMID:24583073

  14. Analysis of the role of phosphorylation in fission yeast Cdc13p/cyclinB function.

    PubMed

    Ren, Liping; Feoktistova, Anna; McDonald, W Hayes; Haese, Greg Den; Morrell, Jennifer L; Gould, Kathleen L

    2005-04-15

    The Cdk1p-cyclin B complex drives entry into mitosis in all eukaryotes. Cdc13p is the single essential cyclin in Schizosaccharomyces pombe and a member of the cyclin B family. Cdc13p abundance rises during G(2)-phase and falls as cells progress through mitosis and G(1). Cdc13p degradation, mediated by the anaphase-promoting complex, is an important mechanism of Cdk1p inhibition and mitotic exit. Cdk1p-cyclin B1 complexes shuttle between the nucleus and cytoplasm, and preventing nuclear accumulation of Cdk1p-cyclin B1 in mammalian cells appears to be one mechanism of preventing entry into mitosis during a DNA damage-induced checkpoint delay. In vertebrates, phosphorylation plays a key role in regulating the intracellular distribution of cyclins. Previous mass spectrometric analysis identified sites of Cdc13p phosphorylation. Here, we have confirmed that these sites are the sole in vivo Cdc13p phosphorylation sites and have studied the role that phosphorylation plays in Cdc13p localization and function. Our data indicate that Cdc13p accumulates in the nucleolus in response to G(2) checkpoint delays, rather than in the cytoplasm, and that phosphorylation plays no role in Cdc13p localization or function. PMID:15705571

  15. A role for VEGF as a negative regulator of pericyte function and vessel maturation.

    PubMed

    Greenberg, Joshua I; Shields, David J; Barillas, Samuel G; Acevedo, Lisette M; Murphy, Eric; Huang, Jianhua; Scheppke, Lea; Stockmann, Christian; Johnson, Randall S; Angle, Niren; Cheresh, David A

    2008-12-11

    Angiogenesis does not only depend on endothelial cell invasion and proliferation: it also requires pericyte coverage of vascular sprouts for vessel stabilization. These processes are coordinated by vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) through their cognate receptors on endothelial cells and vascular smooth muscle cells (VSMCs), respectively. PDGF induces neovascularization by priming VSMCs/pericytes to release pro-angiogenic mediators. Although VEGF directly stimulates endothelial cell proliferation and migration, its role in pericyte biology is less clear. Here we define a role for VEGF as an inhibitor of neovascularization on the basis of its capacity to disrupt VSMC function. Specifically, under conditions of PDGF-mediated angiogenesis, VEGF ablates pericyte coverage of nascent vascular sprouts, leading to vessel destabilization. At the molecular level, VEGF-mediated activation of VEGF-R2 suppresses PDGF-Rbeta signalling in VSMCs through the assembly of a previously undescribed receptor complex consisting of PDGF-Rbeta and VEGF-R2. Inhibition of VEGF-R2 not only prevents assembly of this receptor complex but also restores angiogenesis in tissues exposed to both VEGF and PDGF. Finally, genetic deletion of tumour cell VEGF disrupts PDGF-Rbeta/VEGF-R2 complex formation and increases tumour vessel maturation. These findings underscore the importance of VSMCs/pericytes in neovascularization and reveal a dichotomous role for VEGF and VEGF-R2 signalling as both a promoter of endothelial cell function and a negative regulator of VSMCs and vessel maturation. PMID:18997771

  16. Interference of lateralized distractors on arithmetic problem solving: a functional role for attention shifts in mental calculation.

    PubMed

    Masson, Nicolas; Pesenti, Mauro

    2016-07-01

    Solving arithmetic problems has been shown to induce shifts of spatial attention in simple probe-detection tasks, subtractions orienting attention to the left side and additions to the right side of space. Whether these attentional shifts constitute epiphenomena or are critically linked to the calculation process is still unknown. In the present study, we investigate participants' performance on addition and subtraction solving while they have to detect central or lateralized targets. The results show that lateralized distractors presented in the hemifield congruent to the operation to be solved interfere with arithmetical solving: participants are slower to solve subtractions or additions when distractors are located on the left or on the right, respectively. These results converge with previous data to show that attentional shifts underlie not only number processing but also mental arithmetic. They extend them as they reveal the reverse effect of the one previously reported by showing that inducing attention shifts interferes with the solving of arithmetic problems. They also demonstrate that spatial attentional shifts are part of the calculation procedure of solving mentally arithmetic problems. Their functional role is to access, from the first operand, the representation of the result in a direction congruent to the operation. PMID:25991551

  17. Food additives

    PubMed Central

    Spencer, Michael

    1974-01-01

    Food additives are discussed from the food technology point of view. The reasons for their use are summarized: (1) to protect food from chemical and microbiological attack; (2) to even out seasonal supplies; (3) to improve their eating quality; (4) to improve their nutritional value. The various types of food additives are considered, e.g. colours, flavours, emulsifiers, bread and flour additives, preservatives, and nutritional additives. The paper concludes with consideration of those circumstances in which the use of additives is (a) justified and (b) unjustified. PMID:4467857

  18. Calcineurin/NFAT signaling and innate host defence: a role for NOD1-mediated phagocytic functions

    PubMed Central

    2014-01-01

    The calcineurin/nuclear factor of activated T cells (NFATs) signaling pathway plays a central role in T cell mediated adaptive immune responses, but a number of recent studies demonstrated that calcineurin/NFAT signaling also plays a key role in the control of the innate immune response by myeloid cells. Calcineurin inhibitors, such as cyclosporine A (CsA) and tacrolimus (FK506), are commonly used in organ transplantation to prevent graft rejection and in a variety of immune diseases. These immunosuppressive drugs have adverse effects and significantly increase host’s susceptibility towards bacterial or fungal infections. Recent studies highlighted the role of NFAT signaling in fungal infection and in the control of the pattern recognition receptor nucleotide-binding oligomerization domain-containing protein 1 (NOD1), which predominantly senses invasive Gram-negative bacteria and mediates neutrophil phagocytic functions. This review summarises some of the current knowledge concerning the role of NFAT signaling in the innate immune response and the recent advances on NFAT-dependent inhibition of NOD1-mediated innate immune response caused by CsA, which may contribute to sensitizing transplant recipients to bacterial infection. PMID:24479879

  19. Role of Heat-Shock Proteins in Cellular Function and in the Biology of Fungi

    PubMed Central

    Tiwari, Shraddha; Thakur, Raman; Shankar, Jata

    2015-01-01

    Stress (biotic or abiotic) is an unfavourable condition for an organism including fungus. To overcome stress, organism expresses heat-shock proteins (Hsps) or chaperons to perform biological function. Hsps are involved in various routine biological processes such as transcription, translation and posttranslational modifications, protein folding, and aggregation and disaggregation of proteins. Thus, it is important to understand holistic role of Hsps in response to stress and other biological conditions in fungi. Hsp104, Hsp70, and Hsp40 are found predominant in replication and Hsp90 is found in transcriptional and posttranscriptional process. Hsp90 and Hsp70 in combination or alone play a major role in morphogenesis and dimorphism. Heat stress in fungi expresses Hsp60, Hsp90, Hsp104, Hsp30, and Hsp10 proteins, whereas expression of Hsp12 protein was observed in response to cold stress. Hsp30, Hsp70, and Hsp90 proteins showed expression in response to pH stress. Osmotic stress is controlled by small heat-shock proteins and Hsp60. Expression of Hsp104 is observed under high pressure conditions. Out of these heat-shock proteins, Hsp90 has been predicted as a potential antifungal target due to its role in morphogenesis. Thus, current review focuses on role of Hsps in fungi during morphogenesis and various stress conditions (temperature, pH, and osmotic pressure) and in antifungal drug tolerance. PMID:26881084

  20. Suitability of the microbial community composition and function in a semiarid mine soil for assessing phytomanagement practices based on mycorrhizal inoculation and amendment addition.

    PubMed

    Kohler, J; Caravaca, F; Azcón, R; Díaz, G; Roldán, A

    2016-03-15

    The recovery of species composition and functions of soil microbial community of degraded lands is crucial in order to guarantee the long-term self-sustainability of the ecosystems. A field experiment was carried out to test the influence of combining fermented sugar beet residue (SBR) addition and inoculation with the arbuscular mycorrhizal (AM) fungus Funneliformis mosseae on the plant growth parameters and microbial community composition and function in the rhizosphere of two autochthonous plant species (Dorycnium pentaphyllum L. and Asteriscus maritimus L.) growing in a semiarid soil contaminated by heavy metals. We analysed the phospholipid fatty acids (PLFAs), neutral lipids fatty acids (NLFAs) and enzyme activities to study the soil microbial community composition and function, respectively. The combined treatment was not effective for increasing plant growth. The SBR promoted the growth of both plant species, whilst the AM fungus was effective only for D. pentaphyllum. The effect of the treatments on plant growth was linked to shifts in the rhizosphere microbial community composition and function. The highest increase in dehydrogenase and β-glucosidase activities was recorded in SBR-amended soil. The SBR increased the abundance of marker PLFAs for saprophytic fungi, Gram+ and Gram- bacteria and actinobacteria, whereas the AM fungus enhanced the abundance of AM fungi-related NLFA and marker PLFAs for Gram- bacteria. Measurement of the soil microbial community composition and function was useful to assess the success of phytomanagement technologies in a semiarid, contaminated soil. PMID:26773427