Sample records for accessory function differential

  1. Endocytic Accessory Proteins Are Functionally Distinguished by Their Differential Effects on the Maturation of Clathrin-coated Pits

    Microsoft Academic Search

    Marcel Mettlen; Miriam Stoeber; Dinah Loerke; Costin N. Antonescu; Gaudenz Danuser; Sandra L. Schmid

    2009-01-01

    Diverse cargo molecules (i.e., receptors and ligand\\/receptor complexes) are taken into the cell by clathrin-mediated endocytosis (CME) utilizing a core machinery consisting of cargo-specific adaptors, clathrin and the GTPase dynamin. Numerous endocytic accessory proteins are also required, but their differential roles and functional hierarchy during CME are not yet understood. Here, we used a combination of quantitative live-cell imaging by

  2. UVB Radiation and Human Monocyte Accessory Function: Differential Effects on Pre-Mitotic Events in T-Cell Activation

    Microsoft Academic Search

    Jean Krutmann; Gary M. Kammer; Zahra Toossi; Robert L. Waller; Jerrold J. Ellner; Craig A. Elmets

    1990-01-01

    Purified T lymphocytes fail to proliferate in response to antigenic and mitogenic stimuli when cultured in the presence of accessory cells that have been exposed in vitro to sublethal doses of UVB radiation. Because proliferation represents a final stage in the T-cell activation process, the present study was conducted to determine whether T cells were able to progress through any

  3. Bacteriophage P22 accessory recombination function

    Microsoft Academic Search

    Anthony R. Poteete; Anita C. Fenton; Arlene Semerjian

    1991-01-01

    The accessory recombination function (arf) gene of bacteriophage P22 is located immediately upstream of the essential recombination function (erf) gene. Three mutant alleles of arf were constructed and installed in P22 in place of the wild-type allele: an out-of-frame internal deletion, an in-frame internal deletion, and an amber mutation. The deletion mutant phages are partially defective in homologous recombination and

  4. Alveolar macrophage accessory cell function in bronchial asthma.

    PubMed

    Gant, V; Cluzel, M; Shakoor, Z; Rees, P J; Lee, T H; Hamblin, A S

    1992-10-01

    The capacity of peripheral blood monocytes and alveolar macrophages (AM) obtained by bronchoalveolar lavage (BAL) to present recall antigens, namely, tuberculin purified protein derivative (PPD) or streptokinase-streptodornase (SKSD), to highly purified autologous T-cells has been studied in 11 asthmatic and 11 healthy, nonatopic normal subjects. In the asthmatic group, AM accessory cell function was variable, and most subjects were unable to present either recall antigen as effectively as blood monocytes, although one asthmatic subject demonstrated larger proliferative responses than blood monocytes for both antigens. AM accessory cell activity was not antigen-specific, and there was a correlation between accessory cell efficacy for the two antigens (r = 0.92; confidence interval, 0.53 to 0.98). Furthermore, a correlation existed between the percentage lymphocyte count in the BAL fluid and the ratio of macrophage to monocyte antigen-presenting capability for both PPD (r = 0.92; 95% confidence interval, 0.83 to 0.99) and SKSD (r = 0.90; 95% confidence interval, 0.45 to 0.98). In the normal subjects, AM were also unable to act effectively as accessory cells for the presentation of PPD and SKSD in the majority of subjects. No correlation existed between the percentage lymphocytes in BAL fluid and the ratio of AM to monocyte accessory cell function. These results suggest an association between AM accessory function and the presence of BAL lymphocytes in bronchial asthma. PMID:1416417

  5. Mesangial cell accessory functions: Mediation by intercellular adhesion molecule-1

    Microsoft Academic Search

    Daniel C Brennan; Anthony M Jevnikar; Fumio Takei; Vicki E Reubin-Kelley

    1990-01-01

    Mesangial cell accessory functions: Mediation by intercellular adhesion molecule-1. Mesangial cell (MC) proliferation is an early pathologic alteration characteristic of many forms of immune mediated glomerulonephritis. The intracapillary position, contractile capacity, and production of cytokines and other inflammatory molecules place MC in a pivotal position to initiate, mediate, and direct glomerular damage. We as well as others have noted increased

  6. Acquisition of cell-mediated immunity to Leishmania. II. LSH gene regulation of accessory cell function.

    PubMed Central

    Kaye, P M; Patel, N K; Blackwell, J M

    1988-01-01

    The macrophage natural resistance gene. Lsh, regulates the ability of a selective population of tissue macrophages to control intracellular multiplication of Leishmania donovani by a T-cell independent mechanism. We show here, using mice congenic for Lsh, that this gene also contributes to the acquisition of T-cell-mediated immunity. Whereas both resistant and susceptible mice generate equivalent primary T-cell responses to infection, resistant mice show a rapid increase in accessory cell activity, allowing for greater subsequent T-cell expansion. This change in accessory cell function correlates with increased class II antigen expression relative to susceptible mice, both in vivo during early infection and in vitro in response to induction by interferon-gamma (IFN-gamma). Differences in vitro were independent of, but differentially affected by, amastigote infection. PMID:3141269

  7. Segregated pathways to the vomeronasal amygdala: differential projections from the anterior and posterior divisions of the accessory olfactory bulb.

    PubMed

    Mohedano-Moriano, Alicia; Pro-Sistiaga, Palma; Ubeda-Bañón, Isabel; Crespo, Carlos; Insausti, Ricardo; Martinez-Marcos, Alino

    2007-04-01

    Apically and basally located receptor neurons in the vomeronasal sensory epithelium express G(i2 alpha)- and G(o alpha)-proteins, V1R and V2R vomeronasal receptors, project to the anterior and posterior accessory olfactory bulb and respond to different stimuli, respectively. The extent to which secondary projections from the two portions of the accessory olfactory bulb are convergent in the vomeronasal amygdala is controversial. This issue is addressed by using anterograde and retrograde tract-tracing methods in rats including electron microscopy. Injections of dextran-amines, Fluoro Gold, cholera toxin-B subunit and Fast Blue were delivered to the anterior and posterior accessory olfactory bulb, bed nucleus of the stria terminalis, dorsal anterior amygdala and bed nucleus of the accessory olfactory tract/anteroventral medial amygdaloid nucleus. We have demonstrated that, apart from common vomeronasal-recipient areas, only the anterior accessory olfactory bulb projects to the bed nucleus of the stria terminalis, medial division, posteromedial part, and only the posterior accessory olfactory bulb projects to the dorsal anterior amygdala and deep cell layers of the bed nucleus of the accessory olfactory tract and the anteroventral medial amygdaloid nucleus. These results provide evidence that, excluding areas of convergence, the V1R and V2R vomeronasal pathways project to specific areas of the amygdala. These two vomeronasal subsystems are therefore anatomically and functionally separated in the telencephalon. PMID:17419754

  8. Melanopsin and rod-cone photoreceptive systems account for all major accessory visual functions in mice

    Microsoft Academic Search

    S. Hattar; R. J. Lucas; N. Mrosovsky; S. Thompson; R. H. Douglas; M. W. Hankins; J. Lem; M. Biel; F. Hofmann; R. G. Foster; K.-W. Yau

    2003-01-01

    In the mammalian retina, besides the conventional rod-cone system, a melanopsin-associated photoreceptive system exists that conveys photic information for accessory visual functions such as pupillary light reflex and circadian photo-entrainment. On ablation of the melanopsin gene, retinal ganglion cells that normally express melanopsin are no longer intrinsically photosensitive. Furthermore, pupil reflex, light-induced phase delays of the circadian clock and period

  9. Interleukin-11 promotes accessory cell-dependent B-cell differentiation in humans.

    PubMed

    Anderson, K C; Morimoto, C; Paul, S R; Chauhan, D; Williams, D; Cochran, M; Barut, B A

    1992-12-01

    Interleukin-11 (IL-11) is a recently described stromal-derived cytokine that supports the growth of an IL-6-dependent murine plasmacytoma line in the presence of antibody to IL-6 and appears to act in a manner similar to IL-6 on hematopoietic stem cells. Because IL-6 is known to promote differentiation of normal human B cells, the role of IL-11 on B-cell differentiation in vitro was characterized. IL-11 does not result in significantly increased DNA synthesis or Ig secretion by purified B cells alone or B cells cultured with Staphylococcus Cowan I, a T-cell-independent B-cell mitogen. In contrast, purified B cells cultured in the presence of pokeweed mitogen (PWM), irradiated T cells, and monocytes show increased DNA synthesis at day 3 and increased IgG and IgM secretion at day 7 of culture; addition of IL-11 further augments Ig secretion without change in DNA synthesis, an effect that can only be partially blocked by monoclonal antibody to IL-6. Similar experiments confirmed that increased IgG secretion was demonstrable when either IL-11 or IL-6 was added to B cells + CD4+/45RA- T cells + monocytes + PWM; in contrast, Ig secretion was low and equivalent when CD4+/45RA+ T cells were cultured with B cells+monocytes+PWM with or without IL-6 or IL-11. Neither IL-6 nor IL-11 could significantly increase phytohemagglutinin (PHA)-induced DNA synthesis by CD4+/45RA- or CD4+/45RA+ T cells. Although PWM or IL-11 induced IL-6 mRNA expression in both CD4+/45RA- T cells and monocytes, in neither cell did IL-11 increase IL-6 mRNA expression over that noted to PWM alone. These observations support the view that IL-11 promotes differentiation of human B lymphocytes only in the presence of accessory T cells and monocytes and that a minor component of this effect may be through stimulation of IL-6 production by CD4+/45RA- T cells and monocytes. PMID:1450406

  10. Accessory cell function in the Con A response: role of Ia-positive and Ia-negative accessory cells.

    PubMed

    Bekoff, M; Kakiuchi, T; Grey, H M

    1985-03-01

    We have examined the role of Ia-positive and Ia-negative accessory cells (AC) and soluble factors in Con A-stimulated murine T cell activation. Supernatant fluids containing interleukin 1 (IL 1) derived from the P388D1 macrophage cell line and from a lipopolysaccharide (LPS)-stimulated macrophage hybridoma provided only partial reconstitution of the response of purified T cells (18 to 27%). The complete reconstitution obtained with gamma-irradiated spleen cells or LPS-activated B cells was inhibited by approximately 60 to 77% when anti-Ia antibody was included in the culture. Despite this apparent involvement of Ia+ spleen AC, Ia-negative L cell AC could also reconstitute the response of both Class I-restricted Lyt-2+ T cells and Class II-restricted L3T4+ T cells. When the Ia-negative AC were employed, the L3T4 antigen on L3T4+ T cells played a critical role because addition of anti-L3T4 antibody to the culture inhibited the response by 85 to 90%. In contrast, anti-L3T4 did not inhibit the response in the presence of spleen AC. These results suggest that the molecules involved in T cell-AC interactions may vary depending on the AC source. Moreover, at least one of the putative target ligands for L3T4 presumably is not Ia, because anti-L3T4 inhibited T cell stimulation when Ia-negative AC were used. PMID:3881521

  11. Orthology, Function and Evolution of Accessory Gland Proteins in the Drosophila repleta Group

    PubMed Central

    Almeida, Francisca C.; DeSalle, Rob

    2009-01-01

    The accessory gland proteins (Acps) of Drosophila have become a model for the study of reproductive protein evolution. A major step in the study of Acps is to identify biological causes and consequences of the observed patterns of molecular evolution by comparing species groups with different biology. Here we characterize the Acp complement of Drosophila mayaguana, a repleta group representative. Species of this group show important differences in ecology and reproduction as compared to other Drosophila. Our results show that the extremely high rates of Acp evolution previously found are likely to be ubiquitous among species of the repleta group. These evolutionary rates are considerably higher than the ones observed in other Drosophila groups' Acps. This disparity, however, is not accompanied by major differences in the estimated number of Acps or in the functional categories represented as previously suggested. Among the genes expressed in accessory glands of D. mayaguana almost half are likely products of recent duplications. This allowed us to test predictions of the neofunctionalization model for gene duplication and paralog evolution in a more or less constrained timescale. We found that positive selection is a strong force in the early divergence of these gene pairs. PMID:19015541

  12. Matching Accessories

    NSDL National Science Digital Library

    Steven M. Foord (Stevenage; Target Bioinformatics, GlaxoSmithKline Medicine Research Centre REV)

    2003-07-08

    Heterodimerization enhances the complexity of ligand recognition and diversity of signaling responses of heterotrimeric guanine nucleotide-binding protein-coupled receptors (GPCRs). Many accessory proteins (for ion channels or GPCRs) appear to associate with their partners relatively early in the process whereby proteins are transported to the cell surface; their roles in modulating function may have evolved out of simple proximity to a protein that once upon a time they either facilitated or accompanied through the maturation process. The receptor activity-modifying proteins (RAMPs) are a family of single-transmembrane accessory proteins that heterodimerize with GPCRs and, thereby, allow individual GPCRs to recognize multiple ligands and to activate various signaling pathways in response to ligand binding. The M10 family of major histocompatibility complex (MHC) class 1b proteins has recently been shown to associate with murine vomeronasal V2R receptors, as well as to escort them to the cell surface. The exact role of M10 in modulating V2R function (or vice versa) remains to be determined.

  13. Prevention of ultraviolet radiation-induced suppression of accessory cell function of Langerhans cells by Aloe vera gel components.

    PubMed

    Lee, C K; Han, S S; Mo, Y K; Kim, R S; Chung, M H; Park, Y I; Lee, S K; Kim, Y S

    1997-10-01

    The active components of Aloe vera gel that can prevent ultraviolet B (UVB)-induced suppression of accessory cell function of Langerhans cells (LC) were purified by activity-guided sequential fractionation followed by in vitro functional assay. The functional assay was based on the fact that exposure of freshly isolated murine epidermal cells (EC) to UVB radiation resulted in impairment of accessory cell function of LC, as measured by their ability to support anti-CD3 monoclonal antibody (mAb)-primed T-cell mitogenesis. This UVB-suppressed LC accessory cell function was prevented by addition of partially purified Aloe gel components to cultures of UVB-irradiated EC. The Aloe gel components appeared to prevent events occurring within the first 24 h after UVB irradiation that lead to the impairment of accessory cell function. The Aloe gel components did not cause proliferation of anti-CD3 mAb-primed T-cells, nor did induce proliferation of normal EC. The activity-guided final purification of Aloe gel components resulted in the isolation of two components. Both of the components were small molecular weight (MW) substances with an apparent MW of less than 1,000 Da but different from each other in net charge characteristics at pH 7.4. These results suggest that Aloe vera gel contains at least two small molecular weight immunomodulators that may prevent UVB-induced immune suppression in the skin. PMID:9403333

  14. Using Differentials to Differentiate Trigonometric and Exponential Functions

    ERIC Educational Resources Information Center

    Dray, Tevian

    2013-01-01

    Starting from geometric definitions, we show how differentials can be used to differentiate trigonometric and exponential functions without limits, numerical estimates, solutions of differential equations, or integration.

  15. Shared and differential traits in the accessory olfactory bulb of caviomorph rodents with particular reference to the semiaquatic capybara

    PubMed Central

    Suárez, Rodrigo; Santibáñez, Rodrigo; Parra, Daniela; Coppi, Antonio A; Abrahão, Luciana M B; Sasahara, Tais H C; Mpodozis, Jorge

    2011-01-01

    The vomeronasal system is crucial for social and sexual communication in mammals. Two populations of vomeronasal sensory neurons, each expressing G?i2 or G?o proteins, send projections to glomeruli of the rostral or caudal accessory olfactory bulb, rAOB and cAOB, respectively. In rodents, the G?i2- and G?o-expressing vomeronasal pathways have shown differential responses to small/volatile vs. large/non-volatile semiochemicals, respectively. Moreover, early gene expression suggests predominant activation of rAOB and cAOB neurons in sexual vs. aggressive contexts, respectively. We recently described the AOB of Octodon degus, a semiarid-inhabiting diurnal caviomorph. Their AOB has a cell indentation between subdomains and the rAOB is twice the size of the cAOB. Moreover, their AOB receives innervation from the lateral aspect, contrasting with the medial innervation of all other mammals examined to date. Aiming to relate AOB anatomy with lifestyle, we performed a morphometric study on the AOB of the capybara, a semiaquatic caviomorph whose lifestyle differs remarkably from that of O. degus. Capybaras mate in water and scent-mark their surroundings with oily deposits, mostly for male–male communication. We found that, similar to O. degus, the AOB of capybaras shows a lateral innervation of the vomeronasal nerve, a cell indentation between subdomains and heterogeneous subdomains, but in contrast to O. degus the caudal portion is larger than the rostral one. We also observed that four other caviomorph species present a lateral AOB innervation and a cell indentation between AOB subdomains, suggesting that those traits could represent apomorphies of the group. We propose that although some AOB traits may be phylogenetically conserved in caviomorphs, ecological specializations may play an important role in shaping the AOB. PMID:21457258

  16. Human CLC-K Channels Require Palmitoylation of Their Accessory Subunit Barttin to Be Functional.

    PubMed

    Steinke, Kim Vanessa; Gorinski, Nataliya; Wojciechowski, Daniel; Todorov, Vladimir; Guseva, Daria; Ponimaskin, Evgeni; Fahlke, Christoph; Fischer, Martin

    2015-07-10

    CLC-K/barttin chloride channels are essential for NaCl re-absorption in Henle's loop and for potassium secretion by the stria vascularis in the inner ear. Here, we studied the posttranslational modification of such channels by palmitoylation of their accessory subunit barttin. We found that barttin is palmitoylated in vivo and in vitro and identified two conserved cysteine residues at positions 54 and 56 as palmitoylation sites. Point mutations at these two residues reduce the macroscopic current amplitudes in cells expressing CLC-K/barttin channels proportionally to the relative reduction in palmitoylated barttin. CLC-K/barttin expression, plasma membrane insertion, and single channel properties remain unaffected, indicating that these mutations decrease the number of active channels. R8W and G47R, two naturally occurring barttin mutations identified in patients with Bartter syndrome type IV, reduce barttin palmitoylation and CLC-K/barttin channel activity. Palmitoylation of the accessory subunit barttin might thus play a role in chloride channel dysfunction in certain variants of Bartter syndrome. We did not observe pronounced alteration of barttin palmitoylation upon increased salt and water intake or water deprivation, indicating that this posttranslational modification does not contribute to long term adaptation to variable water intake. Our results identify barttin palmitoylation as a novel posttranslational modification of CLC-K/barttin chloride channels. PMID:26013830

  17. Investigating Differentiability of Piecewise Functions

    NSDL National Science Digital Library

    Roberts, Lila F.

    2004-10-04

    Students in calculus need to be proficient in working with functions in a variety of ways: graphical, numerical, analytic, or verbal, and to understand connections among these representations. This demo provides a set of visualizations designed to help students better understand what it means for a piecewise function to be differentiable at a particular domain value.

  18. Dietary n-3 PUFA affect TcR-mediated activation of purified murine T cells and accessory cell function in co-cultures

    PubMed Central

    CHAPKIN, R S; ARRINGTON, J L; APANASOVICH, T V; CARROLL, R J; MCMURRAY, D N

    2002-01-01

    Diets enriched in n-3 polyunsaturated fatty acids (PUFA) suppress several functions of murine splenic T cells by acting directly on the T cells and/or indirectly on accessory cells. In this study, the relative contribution of highly purified populations of the two cell types to the dietary suppression of T cell function was examined. Mice were fed diets containing different levels of n-3 PUFA; safflower oil (SAF; control containing no n-3 PUFA), fish oil (FO) at 2% and 4%, or 1% purified docosahexaenoic acid (DHA) for 2 weeks. Purified (>90%) T cells were obtained from the spleen, and accessory cells (>95% adherent, esterase-positive) were obtained by peritoneal lavage. Purified T cells or accessory cells from each diet group were co-cultured with the alternative cell type from every other diet group, yielding a total of 16 different co-culture combinations. The T cells were stimulated with either concanavalin A (ConA) or antibodies to the T cell receptor (TcR)/CD3 complex and the costimulatory molecule CD28 (?CD3/?CD28), and proliferation was measured after four days. Suppression of T cell proliferation in the co-cultures was dependent upon the dose of dietary n-3 PUFA fed to mice from which the T cells were derived, irrespective of the dietary treatment of accessory cell donors. The greatest dietary effect was seen in mice consuming the DHA diet (P = 0·034 in the anova; P = 0·0053 in the Trend Test), and was observed with direct stimulation of the T cell receptor and CD28 costimulatory ligand, but not with ConA. A significant dietary effect was also contributed accessory cells (P = 0·033 in the Trend Test). We conclude that dietary n-3 PUFA affect TcR-mediated by T cell activation by both direct and indirect (accessory cell) mechanisms. PMID:12296847

  19. Spinal accessory nerve injury.

    PubMed

    Wiater, J M; Bigliani, L U

    1999-11-01

    Injury to the spinal accessory nerve can lead to dysfunction of the trapezius. The trapezius is a major scapular stabilizer and is composed of three functional components. It contributes to scapulothoracic rhythm by elevating, rotating, and retracting the scapula. The superficial course of the spinal accessory nerve in the posterior cervical triangle makes it susceptible to injury. Iatrogenic injury to the nerve after a surgical procedure is one of the most common causes of trapezius palsy. Dysfunction of the trapezius can be a painful and disabling condition. The shoulder droops as the scapula is translated laterally and rotated downward. Patients present with an asymmetric neckline, a drooping shoulder, winging of the scapula, and weakness of forward elevation. Evaluation should include a complete electrodiagnostic examination. If diagnosed within 1 year of the injury, microsurgical reconstruction of the nerve should be considered. Conservative treatment of chronic trapezius paralysis is appropriate for older patients who are sendentary. Active and healthy patients in whom 1 year of conservative treatment has failed are candidates for surgical reconstruction. Studies have shown the Eden-Lange procedure, in which the insertions of the levator scapulae, rhomboideus minor, and rhomboideus major muscles are transferred, relieves pain, corrects deformity, and improves function in patients with irreparable injury to the spinal accessory nerve. PMID:10613148

  20. Aspergillus terreus accessory conidia are multinucleated, hyperpolarizing structures that display differential dectin staining and can induce heightened inflammatory responses in a pulmonary model of aspergillosis

    PubMed Central

    Deak, Eszter; Nelson, Michael; Hernández-Rodríguez, Yainitza; Gade, Lalitha; Baddley, John; Momany, Michelle; Steele, Chad

    2011-01-01

    In addition to phialidic conidia (PC), A. terreus produces accessory conidia (AC) both in vitro and in vivo. AC are distinct from PC in cell surface architecture, with the AC surfaces displaying more ?-glucan, a molecule that can be a trigger for the induction of inflammatory responses. The present study follows ?-glucan cell surface presentation throughout the course of germination of both types of conidia, and analyzes the differential capacity of AC and PC to elicit immune responses. Results show that AC display early, increased dectin-1 labeling on their cell surfaces compared to PC, and this differential dectin-1 labeling is sustained on the cell surface from the time of breaking dormancy through early germ tube emergence. Mouse alveolar macrophages showed a stronger inflammatory cytokine/chemokine response when challenged with AC than with PC in both ex vivo and in vivo experiments, correlating with the greater exposure of ?-glucan exhibited by AC. Further, histopathologic staining of the lungs from mice challenged with AC demonstrated heightened cell recruitment and increased inflammatory response compared to the lungs of mice challenged with PC. Our study also demonstrates that AC are multinucleate structures with the ability to germinate rapidly, polarizing in multiple directions and producing several hyphal extensions. We present evidence that A. terreus AC are phenotypically distinct from PC and can be potent activators of the innate immune mechanism thus possibly playing a role in this organism's pathogenesis. PMID:21543882

  1. Transient and sustained afterdepolarizations in accessory olfactory bulb mitral cells are mediated by distinct mechanisms that are differentially regulated by neuromodulators

    PubMed Central

    Shpak, Guy; Zylbertal, Asaph; Wagner, Shlomo

    2015-01-01

    Social interactions between mammalian conspecifics rely heavily on molecular communication via the main and accessory olfactory systems. These two chemosensory systems show high similarity in the organization of information flow along their early stages: social chemical cues are detected by the sensory neurons of the main olfactory epithelium and the vomeronasal organ. These neurons then convey sensory information to the main (MOB) and accessory (AOB) olfactory bulbs, respectively, where they synapse upon mitral cells that project to higher brain areas. Yet, the functional difference between these two chemosensory systems remains unclear. We have previously shown that MOB and AOB mitral cells exhibit very distinct intrinsic biophysical properties leading to different types of information processing. Specifically, we found that unlike MOB mitral cells, AOB neurons display persistent firing responses to strong stimuli. These prolonged responses are mediated by long-lasting calcium-activated non-selective cationic current (Ican). In the current study we further examined the firing characteristics of these cells and their modulation by several neuromodulators. We found that AOB mitral cells display transient depolarizing afterpotentials (DAPs) following moderate firing. These DAPs are not found in MOB mitral cells that show instead robust hyperpolarizing afterpotentials. Unlike Ican, the DAPs of AOB mitral cells are activated by low levels of intracellular calcium and are relatively insensitive to flufenamic acid. Moreover, the cholinergic agonist carbachol exerts opposite effects on the persistent firing and DAPs of AOB mitral cells. We conclude that these phenomena are mediated by distinct biophysical mechanisms that may serve to mediate different types of information processing in the AOB at distinct brain states. PMID:25642164

  2. Function of caspase-14 in trophoblast differentiation

    Microsoft Academic Search

    Lloyd J White; Wim Declercq; Frank Arfuso; Adrian K Charles; Arun M Dharmarajan

    2009-01-01

    BACKGROUND: Within the human placenta, the cytotrophoblast consists of a proliferative pool of progenitor cells which differentiate to replenish the overlying continuous, multi-nucleated syncytiotrophoblast, which forms the barrier between the maternal and fetal tissues. Disruption to trophoblast differentiation and function may result in impaired fetal development and preeclampsia. Caspase-14 expression is limited to barrier forming tissues. It promotes keratinocyte differentiation

  3. Detecting Differential Person Functioning in Emotional Intelligence

    ERIC Educational Resources Information Center

    Alsmadi, Yahia M.; Alsmadi, Abdalla A.

    2009-01-01

    Differential Item Functioning (DIF) is a widely used term in test development literature. It is very important to analyze test's data for DIF because It is a serious threat to validity. If the same data matrix was transposed, similar analysis can be carried for Differential Person Functioning (DPF). The purpose of this paper is to introduce and…

  4. Differential Bundle Functioning Using the DFIT Framework: Procedures for Identifying Possible Sources of Differential Functioning.

    ERIC Educational Resources Information Center

    Oshima, T. C.; Raju, Nambury S.; Flowers, Claudia P.; Slinde, Jeffrey A.

    1998-01-01

    A general framework for assessing differential functioning of items and tests (DFIT) that was recently proposed is expanded to include differential bundle functioning as a mechanism for identifying sources of differential functioning. The expansion is illustrated with a dataset of 4000 fourth-grade students from a reading comprehension…

  5. Identifying Possible Sources of Differential Functioning Using Differential Bundle Functioning with Polytomously Scored Data

    ERIC Educational Resources Information Center

    McCarty, F. A.; Oshima, T. C.; Raju, Nambury S.

    2007-01-01

    Oshima, Raju, Flowers, and Slinde (1998) described procedures for identifying sources of differential functioning for dichotomous data using differential bundle functioning (DBF) derived from the differential functioning of items and test (DFIT) framework (Raju, van der Linden, & Fleer, 1995). The purpose of this study was to extend the procedures…

  6. The Laser Accessory Market

    NASA Astrophysics Data System (ADS)

    Desai, Ashvin

    1988-09-01

    Wandering through the exhibit hall yesterday, I noticed that if you look at the laser companies and if you look at the accessory companies, there are pretty much the same number of accessory booths as well as the laser companies. There was one difference. Laser company booths are all sexy looking, very flashy, big booths. Whereas if you look at the accessories booths, they were small, not so prominent.

  7. Screening Test Items for Differential Item Functioning

    ERIC Educational Resources Information Center

    Longford, Nicholas T.

    2014-01-01

    A method for medical screening is adapted to differential item functioning (DIF). Its essential elements are explicit declarations of the level of DIF that is acceptable and of the loss function that quantifies the consequences of the two kinds of inappropriate classification of an item. Instead of a single level and a single function, sets of…

  8. A class of neutral functional differential equations.

    NASA Technical Reports Server (NTRS)

    Melvin, W. R.

    1972-01-01

    Formulation and study of the initial value problem for neutral functional differential equations. The existence, uniqueness, and continuation of solutions to this problem are investigated, and an analysis is made of the dependence of the solutions on the initial conditions and parameters, resulting in the derivation of a continuous dependence theorem in which the fundamental mathematical principles underlying the continuous dependence problem for a very general system of nonlinear neutral functional differential equations are separated out.

  9. Multiple functional roles of the accessory I-domain of bacteriophage P22 coat protein revealed by NMR structure and cryoEM modeling

    PubMed Central

    Rizzo, Alessandro A.; Suhanovsky, Margaret M.; Baker, Matthew L.; Fraser, LaTasha C.R.; Jones, Lisa M.; Rempel, Don L.; Gross, Michael L.; Chiu, Wah; Alexandrescu, Andrei T.; Teschke, Carolyn M.

    2014-01-01

    SUMMARY Some capsid proteins built on the ubiquitous HK97-fold have accessory domains that impart specific functions. Bacteriophage P22 coat protein has a unique inserted I-domain. Two prior I-domain models from sub-nanometer cryoEM reconstructions differed substantially. Therefore, the NMR structure of the I-domain was determined, which also was used to improve cryoEM models of coat protein. The I-domain has an anti-parallel 6-stranded ?-barrel fold, previously not observed in HK97-fold accessory domains. The D-loop, which is dynamic both in the isolated I-domain and intact monomeric coat protein, forms stabilizing salt bridges between adjacent capsomers in procapsids. A newly described S-loop is important for capsid size determination, likely through intra-subunit interactions. Ten of eighteen coat protein temperature-sensitive-folding substitutions are in the I-domain, indicating its importance in folding and stability. Several are found on a positively charged face of the ?-barrel that anchors the I-domain to a negatively charged surface of the coat protein HK97-core. PMID:24836025

  10. Self-injurious behavior: differential diagnosis and functional differentiation.

    PubMed

    Claes, Laurence; Vandereycken, Walter

    2007-01-01

    Although often used as synonyms, "self-injury" and "self-harm" may refer to different behaviors with different meanings. Because the literature is quite confusing in this respect, we propose a more specific delineation of the notion of self-injurious behavior (SIB), differentiated from other self-harming behaviors. For this purpose, we present a flowchart for differential diagnosis. This brings us to the question: are we dealing here with a sign of pathology or a meaningful behavior? We compare the structuralist approach, in which SIB is viewed as either a syndrome or a symptom, with the functionalist approach, focusing on the psychosocial functions of SIB. PMID:17292704

  11. Function of caspase-14 in trophoblast differentiation

    PubMed Central

    White, Lloyd J; Declercq, Wim; Arfuso, Frank; Charles, Adrian K; Dharmarajan, Arun M

    2009-01-01

    Background Within the human placenta, the cytotrophoblast consists of a proliferative pool of progenitor cells which differentiate to replenish the overlying continuous, multi-nucleated syncytiotrophoblast, which forms the barrier between the maternal and fetal tissues. Disruption to trophoblast differentiation and function may result in impaired fetal development and preeclampsia. Caspase-14 expression is limited to barrier forming tissues. It promotes keratinocyte differentiation by cleaving profilaggrin to stabilise keratin intermediate filaments, and indirectly providing hydration and UV protection. However its role in the trophoblast remains unexplored. Methods Using RNA Interference the reaction of control and differentiating trophoblastic BeWo cells to suppressed caspase-14 was examined for genes pertaining to hormonal, cell cycle and cytoskeletal pathways. Results Transcription of hCG, KLF4 and cytokeratin-18 were increased following caspase-14 suppression suggesting a role for caspase-14 in inhibiting their pathways. Furthermore, hCG, KLF4 and cytokeratin-18 protein levels were disrupted. Conclusion Since expression of these molecules is normally increased with trophoblast differentiation, our results imply that caspase-14 inhibits trophoblast differentiation. This is the first functional study of this unusual member of the caspase family in the trophoblast, where it has a different function than in the epidermis. This knowledge of the molecular underpinnings of trophoblast differentiation may instruct future therapies of trophoblast disease. PMID:19747408

  12. Accessories Around the Clock. 

    E-print Network

    Boyles, Rheba Merle; Hard, Graham; Roberson, Nena; Eaton, Fannie Brown

    1958-01-01

    Accessories Around the Clock RHEBA MERLE BOYLES GRAHAM HARD NENA ROBERSON FANNIE BROWN EATON Extension Clothing Specialists k. The Texas A. a M. College System 2? well-dressed woman of today believes a wardrobe of fewer q, well chosen...

  13. Distinguishing Differential Testlet Functioning From Differential Bundle Functioning Using the Multilevel Measurement Model

    Microsoft Academic Search

    S. Natasha Beretvas; Cindy M. Walker

    2012-01-01

    This study extends the multilevel measurement model to handle testlet-based dependencies. A flexible two-level testlet response model (the MMMT-2 model) for dichotomous items is introduced that permits assessment of differential testlet functioning (DTLF). A distinction is made between this study’s conceptualization of DTLF and that of differential bundle functioning (DBF) with an emphasis on the practical utility of decomposing differential

  14. Examining the Relationship between Differential Item Functioning and Differential Test Functioning

    ERIC Educational Resources Information Center

    Pae, Tae-Il; Park, Gi-Pyo

    2006-01-01

    The present study utilized both the IRT-LR (item response theory likelihood ratio) and a series of CFA (confirmatory factor analysis) multi-sample analyses to systematically examine the relationships between DIF (differential item functioning) and DTF (differential test functioning) with a random sample of 15 000 Korean examinees. Specifically,…

  15. Dendritic cells are specialized accessory cells along with TGF-? for the differentiation of Foxp3+ CD4+ regulatory T cells from peripheral Foxp3? precursors

    PubMed Central

    Bonito, Anthony J.; Spisek, Radek; Dhodapkar, Madhav; Inaba, Kayo; Steinman, Ralph M.

    2007-01-01

    Foxp3+CD25+CD4+ regulatory T cells are produced in the thymus (natural T regs) but can also differentiate from peripheral Foxp3?CD4+ precursors (induced or adaptive T regs). We assessed antigen presenting cell (APC) requirements for the latter differentiation. With added transforming growth factor (TGF)-?, both immature and mature populations of dendritic cells (DCs) induced antigen-specific Foxp3+ T regs from Foxp3? precursors. Using endogenous TGF-?, DCs from gut-associated mesenteric lymph nodes were capable of differentiating Foxp3+T regs. Spleen DCs were 100-fold more potent than DC-depleted APCs for the induction of T regs and required 10-fold lower doses of peptide antigen. Interleukin-2 (IL-2) was essential, but could be provided endogenously by T cells stimulated by DCs, but not other APCs. The required IL-2 was induced by DCs that expressed CD80/CD86 costimulatory molecules. The DC-induced Foxp3+T regs divided up to 6 times in 6 days and were comprised of CD62L and CD103 positive and negative forms. The induced Foxp3+T regs exerted suppression in vitro and blocked tumor immunity in vivo. These results indicate that DCs are specialized to differentiate functional peripheral Foxp3+T regs and help set the stage to use DCs to actively suppress the immune response in an antigen-specific manner. PMID:17699744

  16. Regular Functions Satisfying Irregular Ordinary Differential Equations

    Microsoft Academic Search

    Jill Guerra; Harold S. Shapiro

    2003-01-01

    This paper deals with entire solutions to linear ordinary differential equations in the complex domain. We show that certain entire solutions to singular equations, cannot satisfy any normalized equation without singularities. We provide two proofs of this result, one based on the indicial equation and the other using the Frobenius notion of irreducibility. Our examples include the entire Bessel function.

  17. A Reconceptualization of Differential Item Functioning.

    ERIC Educational Resources Information Center

    De Ayala, R. J.; Kim, Seock-Ho; Stapleton, Laura M.; Dayton, C. Mitchell

    Differential item functioning (DIF) may be defined as an item that displays different statistical properties for different groups after the groups are matched on an ability measure. For instance, with binary data, DIF exists when there is a difference in the conditional probabilities of a correct response for two manifest groups. This paper…

  18. Accessories Around the Clock.

    E-print Network

    Boyles, Rheba Merle; Hard, Graham; Roberson, Nena; Eaton, Fannie Brown

    1958-01-01

    ~t~.~~, r as the basic garment; varied colors I be used in smaller, less expensive ac- jories. Good leather bags, gloves and - rather than na Ies are a park of a well-dressed person, - smoothiy. fmishd. >Q. . . . .- . A should .;b= considered...~~i The effect usually is spotted if two bright-colored matching 4 are worn at one time. One brighd accessory often is smarter than @ the other accessories harmonizing If a brilliant hat is worn wih a bl wear dark shoes and bag. 'a 1 Gloves may match...

  19. Functions of one variable. Differentiation 1. Function notion, function graph, boundedness. Monotone, inverse functions, even,

    E-print Network

    Levant, Arie

    Functions of one variable. Differentiation 1. Function notion, function graph, boundedness and Maclourin formulas. (const) = 0; (x ) = x -1 ; ( x ) = 1 2 x ; 1 x = - 1 2 x ; (sin x) = cos x ; (cos x) = -sin x ; (tg x) = 1 2 cos x ; (ctg x) = - 1 2 sin x ; (arcsin x) = 1 1 2 - x ; (arccos x

  20. Functional defects in peripheral blood T cells of multiple sclerosis patients. Diminished in vitro responsiveness in accessory cell dependent activation systems.

    PubMed

    Rep, M H; Hintzen, R Q; Polman, C H; van Lier, R A

    1994-07-01

    Function and phenotype of peripheral blood (PB) T cells in multiple sclerosis (MS) patients were analyzed. In whole blood cultures, T cell proliferation of multiple sclerosis (MS) patients, using soluble CD3 mAb and CD2 mAb as stimulants, was reduced in comparison to healthy controls. A similar difference was seen when isolated PBMC were tested after stimulation with soluble CD3 mAb. However, in accessory cell-independent activation systems, i.e. after stimulation of PBMC with immobilized CD3 mAb or after co-stimulation with CD28 mAb, both patients and controls responded equally well. Phenotypical analysis of the circulating T cell population showed that there were no differences in the percentage of CD26+, 'memory' (CD45R0+) or 'effector' (CD4+CD45R0+CD27-) cells between MS patients and healthy controls. Finally, although MS patients did show an enhanced proportion of 'naive' (CD4+CD45RA+) T cells, this did not correlate with the observed functional defects. PMID:8034753

  1. Vitamin D, phagocyte differentiation and immune function

    Microsoft Academic Search

    T. Kenney Gray; Myron S. Cohen

    1985-01-01

    Conclusion  The data reviewed in this paper supports the hypothesis that 1,25-(OH)2D3 influences the differentiation and function of mononuclear phagocytes and lymphocytes. A caveat is the concentrations of\\u000a 1,25-(OH)2D3 required in vitro for expression of these effects. The relevance of these concentrations to the actions of 1,25-(OH)2D3 in vivo is speculative because the experimental conditions involve the presence of serum (and

  2. Distinguishing Differential Testlet Functioning from Differential Bundle Functioning Using the Multilevel Measurement Model

    ERIC Educational Resources Information Center

    Beretvas, S. Natasha; Walker, Cindy M.

    2012-01-01

    This study extends the multilevel measurement model to handle testlet-based dependencies. A flexible two-level testlet response model (the MMMT-2 model) for dichotomous items is introduced that permits assessment of differential testlet functioning (DTLF). A distinction is made between this study's conceptualization of DTLF and that of…

  3. Analytic solutions of a class of iterative functional differential equations

    NASA Astrophysics Data System (ADS)

    Si, Jianguo; Zhang, Weinian

    2004-01-01

    Analytic solutions are obtained for iterative functional differential equations that are natural extensions of x'=1/x[ring operator]x. We make use of neutral functional differential equations with proportional delays as well as neutral differential-difference equations for achieving our purposes.

  4. Surgical management of accessory parotid tumors.

    PubMed

    Rodino, W; Shaha, A R

    1993-11-01

    Accessory parotid gland tumors are defined as masses within salivary gland tissue located adjacent to Stensen's duct, but separate from the main body of the parotid gland. These tumors usually present as asymptomatic cheek masses. There is a temptation to excise these masses locally; however, the likelihood of injury to branches of the facial nerve is high. The best surgical approach to tumors in the accessory parotid region is via a standard parotid incision and concomitant superficial parotidectomy. Eight patients have been surgically treated with accessory parotid gland masses. Six patients had mixed tumors, one had a low grade mucoepidermoid carcinoma, and one had a localized parotitis. Our approach included a standard parotid incision, raising an anterior flap beyond the mass, and exposing the main trunk of the facial nerve, with careful tracing of all its branches. This approach to accessory parotid gland tumors is superior in that it provides a better margin of resection and minimizes functional and cosmetic deformities. Most importantly, there is less danger of injury to branches of the facial nerve. PMID:8412169

  5. Thermomechanical milling of accessory lithics in volcanic conduits

    NASA Astrophysics Data System (ADS)

    Campbell, Michelle E.; Russell, James K.; Porritt, Lucy A.

    2013-09-01

    Accessory lithic clasts recovered from pyroclastic deposits commonly result from the failure of conduit wall rocks, and represent an underutilized resource for constraining conduit processes during explosive volcanic eruptions. The morphological features of lithic clasts provide distinctive 'textural fingerprints' of processes that have reshaped them during transport in the conduit. Here, we present the first study focused on accessory lithic clast morphology and show how the shapes and surfaces of these accessory pyroclasts can inform on conduit processes. We use two main types of accessory lithic clasts from pyroclastic fallout deposits of the 2360 B.P. subplinian eruption of Mount Meager, British Columbia, as a case study: (i) rough and subangular dacite clasts, and (ii) variably rounded and smoothed monzogranite clasts. The quantitative morphological data collected on these lithics include: mass, volume, density, 2-D image analysis of convexity (C), and 3-D laser scans for sphericity (?) and smoothness (S). Shaping and comminution (i.e. milling) of clasts within the conduit are ascribed to three processes: (1) disruptive fragmentation due to high-energy impacts between clasts or between clasts and conduit walls, (2) ash-blasting of clasts suspended within the volcanic flux, and (3) thermal effects. We use a simplified conduit eruption model to predict ash-blasting velocities and lithic residence times as a function of clast size and source depth, thereby constraining the lithic milling processes. The extent of shape and surface modification (i.e. rounding and honing) is directly proportional to clast residence times within the conduit prior to evacuation. We postulate that the shallow-seated dacite clasts remain subangular and rough due to short (<2 min) residence times, whereas monzogranite clasts are much more rounded and smoothed due to deeper source depths and consequently longer residence times (up to ˜1 h). Larger monzogranite clasts are smoother than smaller clasts due to longer residence times and to greater differential velocities within the ash-laden jet. Lastly, our model residence times and mass loss estimates for rounded clasts are used to estimate minimum attrition rates due to volcanic ash-blasting within the conduit (e.g., 12 cm3?s-1 for 25 cm clasts, sourced at 2500 m depth).

  6. Legendre-Tau approximations for functional differential equations

    NASA Technical Reports Server (NTRS)

    Ito, K.; Teglas, R.

    1983-01-01

    The numerical approximation of solutions to linear functional differential equations are considered using the so called Legendre tau method. The functional differential equation is first reformulated as a partial differential equation with a nonlocal boundary condition involving time differentiation. The approximate solution is then represented as a truncated Legendre series with time varying coefficients which satisfy a certain system of ordinary differential equations. The method is very easy to code and yields very accurate approximations. Convergence is established, various numerical examples are presented, and comparison between the latter and cubic spline approximations is made.

  7. HIV Accessory Proteins versus Host Restriction Factors

    PubMed Central

    Strebel, Klaus

    2013-01-01

    Primate immunodeficiency viruses, including HIV-1, are characterized by the presence of accessory genes such as vif, vpr, vpx, vpu, and nef. Current knowledge indicates that none of the primate lentiviral accessory proteins has enzymatic activity. Instead, these proteins interact with cellular ligands to either act as adapter molecules to redirect the normal function of host factors for virus-specific purposes or to inhibit a normal host function by mediating degradation or causing intracellular mislocalization/sequestration of the factors involved. This review aims at providing an update of our current understanding of how Vif, Vpu, and Vpx control the cellular restriction factors APOBEC3G, BST-2, and SAMHD1, respectively. PMID:24246762

  8. Differential expression of functional nucleoside transporters in non-differentiated and differentiated human endothelial progenitor cells.

    PubMed

    Guzmán-Gutiérrez, E; Sandoval, C; Nova, E; Castillo, J L; Vera, J C; Lamperti, L; Krause, B; Salomón, C; Sepúlveda, C; Aguayo, C; Sobrevia, L

    2010-10-01

    Extracellular adenosine removal is via human equilibrative nucleoside transporters 1 (hENT1) and 2 (hENT2) in the endothelium, thus regulating adenosine-induced revascularization and angiogenesis. Since human endothelial progenitor cells (hEPCs) promote revascularization, we hypothesize differential expression of nucleoside transporters in hEPCs. hEPCs were cultured 3 (hEPC-3d) or 14 (hEPC-14d) days. RT-PCR for prominin 1, CD34, octamer-4, kinase insert domain receptor, oxidized low-density lipoprotein (lectin-like) receptor 1 and tyrosine endothelial kinase was used to evaluate phenotypic differentiation. Flow cytometry was used to estimate CD34(+)/KDR(-) (non-differentiated), CD34(-)/KDR(+) (differentiated) or CD34(+)/KDR(+) (mixed) cell populations. Adenosine transport was measured in absence or presence of sodium, S-(4-nitrobenzyl)-6-thio-inosine (NBTI, 1-10 ?M), inosine, hypoxanthine or guanine (0.1-5 mM), hENTs protein abundance by western blot, and hENTs, hCNT1, hCNT2 and hCNT3 mRNA expression by real time RT-PCR. hEPC-3d cells were CD34(+)/KDR(-) compared with hEPC-14d cells that were CD34(-)/KDR(+). hEPC-3d cells exhibit hENT1-like adenosine transport (NBTI-sensitive, Na(+)-independent), which is absent in hEPC-14d cells. hEPC-14d cells exhibit two transport components: component 1 (NBTI insensitive, Na(+)-independent) and component 2 (NBTI insensitive, Na(+)-dependent, Hill coefficient ?1.8), the latter resembling CNT3-like transport. hEPC-3d cells express hENT1 protein and mRNA, which is reduced (?90%) in hEPC-14d cells, but instead only hCNT3 mRNA is expressed in this cell type. hENT2, hCNT1 and hCNT2 were undetectable in hEPCs. Thus, hEPCs exhibit a differential expression of hENT1 and hCNT3 functional nucleoside transporters, which could be related with its differentiation stage. PMID:20728214

  9. An evolutionarily conserved family of accessory subunits of K + channels

    Microsoft Academic Search

    Shi-Qing Cai; Ki Ho Park; Federico Sesti

    2006-01-01

    Accessory subunits are an essential feature of voltage-gated potassium (Kv) channels. They determine trafficking to the plasma\\u000a membrane, surface expression, gating, permeation, and pharmacology. At least three distinct classes of accessory subunits\\u000a including the KCNE family can regulate Kv channel function. KCNE genes encode integral membrane proteins with a single transmembrane\\u000a domain. KCNE genes span the eukaryotic kingdom and, in

  10. Subclasses of vomeronasal receptor neurons: differential expression of G proteins (G i?2 and G o?) and segregated projections to the accessory olfactory bulb

    Microsoft Academic Search

    Changping Jia; Mimi Halpern

    1996-01-01

    Differential expression of G proteins (Gi?2 and Go?) and the separate central projections of Gi?2- and Go?-immunoreactive (ir) vomeronasal receptor neurons were investigated in the mouse and rat using immunocytochemical methods. In the vomeronasal organ (VNO), receptor neurons with their cell bodies located in the middle layer (middle 1\\/3) of the vomeronasal sensory epithelium express Gi?2. Axons of these Gi?2-ir

  11. Net and Global Differential Item Functioning in PISA Polytomously Scored Science Items: Application of the Differential Step Functioning Framework

    ERIC Educational Resources Information Center

    Akour, Mutasem; Sabah, Saed; Hammouri, Hind

    2015-01-01

    The purpose of this study was to apply two types of Differential Item Functioning (DIF), net and global DIF, as well as the framework of Differential Step Functioning (DSF) to real testing data to investigate measurement invariance related to test language. Data from the Program for International Student Assessment (PISA)-2006 polytomously scored…

  12. Curriculum, Translation, and Differential Functioning of Measurement and Geometry Items

    ERIC Educational Resources Information Center

    Emenogu, Barnabas C.; Childs, Ruth A.

    2005-01-01

    A test item exhibits differential item functioning (DIF) if students with the same ability find it differentially difficult. When the item is administered in French and English, differences in language difficulty and meaning are the most likely explanations. However, curriculum differences may also contribute to DIF. The responses of Ontario…

  13. Using Radial Basis Functions to Approximate Battery Differential Capacity and Differential Voltage

    SciTech Connect

    Jon P. Christophersen; Steven R. Shaw

    2010-02-01

    As part of the Department of Energy’s Applied Battery Research Program, lithium-ion cells of various sizes and chemistries are aged with periodic reference performance tests to ascertain degradation rates. The reference tests included a very slow discharge and charge based on a constant current equal to 1/25th of the rated capacity to elucidate the true electrochemical capacity of the cell. A differential analysis of these data helps to identify the individual kinetic and thermodynamic contributions of the anode and cathode. However, differential curves are very noisy, and previous smoothing methods included simple data reduction and moving averages. This paper introduces an alternative method of finding the differential voltage and differential capacity curves based on radial basis functions. The voltage profile is fit with a number of Gaussian curves, and the resulting model is differentiated. This approach also has the added advantage of assessing model uncertainty based on a bootstrap analysis. The radial basis function method was successfully applied to various lithium-ion chemistries tested under the Applied Battery Research Program. The resulting differential capacity and differential voltage curves were generally smoother than the corresponding curves found by previous methods and also showed little variance, indicating a good model fit. These results imply that the radial basis function technique is a more robust tool for assessing differential data.

  14. Functional differentiability in time-dependent quantum mechanics.

    PubMed

    Penz, Markus; Ruggenthaler, Michael

    2015-03-28

    In this work, we investigate the functional differentiability of the time-dependent many-body wave function and of derived quantities with respect to time-dependent potentials. For properly chosen Banach spaces of potentials and wave functions, Fréchet differentiability is proven. From this follows an estimate for the difference of two solutions to the time-dependent Schrödinger equation that evolve under the influence of different potentials. Such results can be applied directly to the one-particle density and to bounded operators, and present a rigorous formulation of non-equilibrium linear-response theory where the usual Lehmann representation of the linear-response kernel is not valid. Further, the Fréchet differentiability of the wave function provides a new route towards proving basic properties of time-dependent density-functional theory. PMID:25833571

  15. Roots in differential rings of ultradifferentiable functions

    Microsoft Academic Search

    Tejinder Singh Neelon

    2007-01-01

    Let {M\\u000a \\u000a k\\u000a } be a logconvex sequence satisfying the differentiability condition \\u000a \\u000a \\u000a \\u000a \\u000a $$\\\\sup (M_{n + 1} \\/M_n )^{1\\/n} < \\\\infty $$\\u000a \\u000a \\u000a \\u000a \\u000a \\u000a . It is shown that the Carleman class C{k! M\\u000a \\u000a k\\u000a } contains all C\\u000a ? roots of its nonflat elements, i.e., if f ? C{k! M\\u000a \\u000a k\\u000a } and ? > 0, then \\u000a \\u000a \\u000a \\u000a \\u000a $$f^\\\\alpha \\\\in C\\\\{ k!M_k \\\\}

  16. Generating functionals and Lagrangian partial differential equations

    SciTech Connect

    Vankerschaver, Joris; Liao, Cuicui; Leok, Melvin [Department of Mathematics, University of California, San Diego, 9500 Gilman Drive, Dept. 0112, La Jolla, California 92093-0112 (United States)] [Department of Mathematics, University of California, San Diego, 9500 Gilman Drive, Dept. 0112, La Jolla, California 92093-0112 (United States)

    2013-08-15

    The main goal of this paper is to derive an alternative characterization of the multisymplectic form formula for classical field theories using the geometry of the space of boundary values. We review the concept of Type-I/II generating functionals defined on the space of boundary data of a Lagrangian field theory. On the Lagrangian side, we define an analogue of Jacobi's solution to the Hamilton–Jacobi equation for field theories, and we show that by taking variational derivatives of this functional, we obtain an isotropic submanifold of the space of Cauchy data, described by the so-called multisymplectic form formula. As an example of the latter, we show that Lorentz's reciprocity principle in electromagnetism is a particular instance of the multisymplectic form formula. We also define a Hamiltonian analogue of Jacobi's solution, and we show that this functional is a Type-II generating functional. We finish the paper by defining a similar framework of generating functions for discrete field theories, and we show that for the linear wave equation, we recover the multisymplectic conservation law of Bridges.

  17. 14 CFR 33.25 - Accessory attachments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...accessory drive and mounting attachments loaded. Each engine accessory drive and mounting attachment must include provisions...A drive and mounting attachment requiring lubrication...to prevent unacceptable loss of oil and to...

  18. HAL-13Feb2006 A differential identity for Green functions

    E-print Network

    Paris-Sud XI, Université de

    . In many-body theory, P describes the interaction Hamiltonian and the identity yields a hierarchy of GreenHAL-13Feb2006 A differential identity for Green functions Christian Brouder Institut de Min with constant coefficients, an identity is derived to calculate the action of eP on the product of two functions

  19. Detection of Differential Item Functioning in the Graded Response Model.

    ERIC Educational Resources Information Center

    Cohen, Allan S.; And Others

    1993-01-01

    Three measures of differential item functioning for the dichotomous response model are extended to include Samejima's graded response model. Two are based on area differences between item true score functions, and one is a chi-square statistic for comparing differences in item parameters. (SLD)

  20. Raju's Differential Functioning of Items and Tests (DFIT)

    ERIC Educational Resources Information Center

    Oshima, T. C.; Morris, S. B.

    2008-01-01

    Nambury S. Raju (1937-2005) developed two model-based indices for differential item functioning (DIF) during his prolific career in psychometrics. Both methods, Raju's area measures (Raju, 1988) and Raju's DFIT (Raju, van der Linden, & Fleer, 1995), are based on quantifying the gap between item characteristic functions (ICFs). This approach…

  1. Decisions that Make a Difference in Detecting Differential Item Functioning

    ERIC Educational Resources Information Center

    Sireci, Stephen G.; Rios, Joseph A.

    2013-01-01

    There are numerous statistical procedures for detecting items that function differently across subgroups of examinees that take a test or survey. However, in endeavouring to detect items that may function differentially, selection of the statistical method is only one of many important decisions. In this article, we discuss the important decisions…

  2. The fully-differential quark beam function at NNLO

    NASA Astrophysics Data System (ADS)

    Gaunt, Jonathan R.; Stahlhofen, Maximilian

    2014-12-01

    We present the first calculation of a fully-unintegrated parton distribution (beam function) at next-to-next-to-leading order (NNLO). We obtain the fully-differential beam function for quark-initiated processes by matching it onto standard parton distribution functions (PDFs) at two loops. The fully-differential beam function is a universal ingredient in resummed predictions of observables probing both the virtuality as well as the transverse momentum of the incoming quark in addition to its usual longitudinal momentum fraction. For such double-differential observables our result provides the part of the NNLO singular cross section related to collinear initial-state radiation (ISR), and is important for the resummation of large logarithms through N3LL.

  3. Solution of partial differential equations by a global radial basis function-based differential quadrature method

    Microsoft Academic Search

    C Shu; H Ding; K. S Yeo

    2004-01-01

    The conventional differential quadrature (DQ) method is limited in its application to regular regions by using functional values along a mesh line to approximate derivatives. In this work, we extend the idea of DQ method to a general case. In other words, any spatial derivative is approximated by a linear weighted sum of all the functional values in the whole

  4. Hyperglycemia enhances function and differentiation of adult rat cardiac fibroblasts.

    PubMed

    Shamhart, Patricia E; Luther, Daniel J; Adapala, Ravi K; Bryant, Jennifer E; Petersen, Kyle A; Meszaros, J Gary; Thodeti, Charles K

    2014-07-01

    Diabetes is an independent risk factor for cardiovascular disease that can eventually cause cardiomyopathy and heart failure. Cardiac fibroblasts (CF) are the critical mediators of physiological and pathological cardiac remodeling; however, the effects of hyperglycemia on cardiac fibroblast function and differentiation is not well known. Here, we performed a comprehensive investigation on the effects of hyperglycemia on cardiac fibroblasts and show that hyperglycemia enhances cardiac fibroblast function and differentiation. We found that high glucose treatment increased collagen I, III, and VI gene expression in rat adult cardiac fibroblasts. Interestingly, hyperglycemia increased CF migration and proliferation that is augmented by collagen I and III. Surprisingly, we found that short term hyperglycemia transiently inhibited ERK1/2 activation but increased AKT phosphorylation. Finally, high glucose treatment increased spontaneous differentiation of cardiac fibroblasts to myofibroblasts with increasing passage compared with low glucose. Taken together, these findings suggest that hyperglycemia induces cardiac fibrosis by modulating collagen expression, migration, proliferation, and differentiation of cardiac fibroblasts. PMID:24959995

  5. BA (Hons) Fashion Accessory Design Course content

    E-print Network

    Evans, Paul

    BA (Hons) Fashion Accessory Design Course content Year One During the first year you will be introduced to the fundamentals of the fashion accessory design process. Year One modules Design Principles and an understanding of the design process. Lectures during this module will introduce key ideas in fashion accessory

  6. Differential Impact of Parent Functioning on Infant Social Emotional Functioning During the Transition to Parenthood 

    E-print Network

    Carhart, Kathryn Patricia

    2012-07-16

    The current study examined the relations between parental and relationship functioning and infant social-emotional functioning, with an emphasis on the differential predictive power of mothers and fathers. This is the first study to examine certain...

  7. news update Fashion Accessory Design

    E-print Network

    Evans, Paul

    news update let's talk Fashion Accessory Design Fashion Design Fashion Knitwear Design and Knitted-year Fashion Knitwear Design and Knitted Textiles student Thea Sanders won the top knitwear prize at the event) Fashion Design student Adnan Ebo, whose bold prints were a hot topic during the event. Adnan's work even

  8. Liouville theory, {N} = 2 gauge theories and accessory parameters

    NASA Astrophysics Data System (ADS)

    Ferrari, Franco; Piatek, Marcin

    2012-05-01

    The correspondence between the semiclassical limit of the DOZZ quantum Liouville theory and the Nekrasov-Shatashvili limit of the {N} = 2 (?-deformed) U(2) super-Yang-Mills theories is used to calculate the unknown accessory parameter of the Fuchsian uniformization of the 4-punctured sphere. The computation is based on the saddle point method. This allows to find an analytic expression for the N f = 4, U(2) instanton twisted superpotential and, in turn, to sum up the 4-point classical block. It is well known that the critical value of the Liouville action functional is the generating function of the accessory parameters. This statement and the factorization property of the 4-point action allow to express the unknown accessory parameter as the derivative of the 4-point classical block with respect to the modular parameter of the 4-punctured sphere. It has been found that this accessory parameter is related to the sum of all rescaled column lengths of the so-called 'critical' Young diagram extremizing the instanton 'free energy'. It is shown that the sum over the 'critical' column lengths can be rewritten in terms of a contour integral in which the integrand is built out of certain special functions closely related to the ordinary Gamma function.

  9. On Parameter Differentiation for Integral Representations of Associated Legendre Functions

    NASA Astrophysics Data System (ADS)

    Cohl, Howard S.

    2011-05-01

    For integral representations of associated Legendre functions in terms of modified Bessel functions, we establish justification for differentiation under the integral sign with respect to parameters. With this justification, derivatives for associated Legendre functions of the first and second kind with respect to the degree are evaluated at odd-half-integer degrees, for general complex-orders, and derivatives with respect to the order are evaluated at integer-orders, for general complex-degrees. We also discuss the properties of the complex function f: C\\{-1,1}?C given by f(z)=z/((z+1)1/2(z-1)1/2).

  10. An Analysis of Differential Item Functioning Based on Calculator Type.

    ERIC Educational Resources Information Center

    Schwarz, Richard; Rich, Changhua; Arenson, Ethan; Podrabsky, Tracy; Cook, Gary

    The effect of calculator type on student performance on a mathematics examination was studied. Differential item functioning (DIF) methodology was applied to examine group differences (calculator use) on item performance while conditioning on the relevant ability. Other survey questions were developed to ask students the extent to which they used…

  11. Differential Item Functioning (DIF): Current Problems and Future Directions

    ERIC Educational Resources Information Center

    Karami, Hossein; Salmani Nodoushan, Mohammad Ali

    2011-01-01

    With the rising concerns over the fairness of language tests, Differential Item Functioning (DIF) has been increasingly applied in bias analysis. Despite its widespread use in psychometric circles, DIF is facing a number of serious problems. This paper is an attempt to shed light on a number of the issues involved in DIF analysis. Specifically,…

  12. A Comparison of Methods for Detecting Differential Distractor Functioning

    ERIC Educational Resources Information Center

    Koon, Sharon

    2010-01-01

    This study examined the effectiveness of the odds-ratio method (Penfield, 2008) and the multinomial logistic regression method (Kato, Moen, & Thurlow, 2009) for measuring differential distractor functioning (DDF) effects in comparison to the standardized distractor analysis approach (Schmitt & Bleistein, 1987). Students classified as participating…

  13. Effect of Multiple Testing Adjustment in Differential Item Functioning Detection

    ERIC Educational Resources Information Center

    Kim, Jihye; Oshima, T. C.

    2013-01-01

    In a typical differential item functioning (DIF) analysis, a significance test is conducted for each item. As a test consists of multiple items, such multiple testing may increase the possibility of making a Type I error at least once. The goal of this study was to investigate how to control a Type I error rate and power using adjustment…

  14. Evaluating the Magnitude of Differential Item Functioning in Polytomous Items.

    ERIC Educational Resources Information Center

    Zwick, Rebecca; Thayer, Dorothy T.

    1996-01-01

    Two possible standard error formulas for the polytomous differential item functioning index proposed by N. J. Dorans and A. P. Schmitt (1991) were derived. These standard errors, and associated hypothesis-testing procedures, were evaluated through simulated data. The standard error that performed better is based on N. Mantel's (1963)…

  15. A Graphic Procedure for Studying Differential Item Functioning.

    ERIC Educational Resources Information Center

    Diamond, James J.

    1992-01-01

    A graphic procedure is presented for studying differential item functioning (DIF) that is designed to provide diagnostic information for psychometricians and educators. The procedure provides a signature of each test item that can be used with a summary statistic to flag items with DIF. Advantages and limitations are noted. (SLD)

  16. An ANOVA-Like Rasch Analysis of Differential Item Functioning.

    ERIC Educational Resources Information Center

    Wang, Wen-Chung

    The conventional two-group differential item functioning (DIF) analysis is extended to an analysis of variance-like (ANOVA-like) DIF analysis where multiple factors with multiple groups are compared simultaneously. Moreover, DIF is treated as a parameter to be estimated rather than simply a sign to be detected. This proposed approach allows the…

  17. MIMIC Methods for Assessing Differential Item Functioning in Polytomous Items

    ERIC Educational Resources Information Center

    Wang, Wen-Chung; Shih, Ching-Lin

    2010-01-01

    Three multiple indicators-multiple causes (MIMIC) methods, namely, the standard MIMIC method (M-ST), the MIMIC method with scale purification (M-SP), and the MIMIC method with a pure anchor (M-PA), were developed to assess differential item functioning (DIF) in polytomous items. In a series of simulations, it appeared that all three methods…

  18. Bounded and periodic solutions of nonlinear functional differential equations

    SciTech Connect

    Slyusarchuk, Vasilii E [Ukranian State Academy of Water Economy (Ukraine)

    2012-05-31

    Conditions for the existence of bounded and periodic solutions of the nonlinear functional differential equation d{sup m}x(t)/dt{sup m} + (Fx)(t) = h(t), t element of R, are presented, involving local linear approximations to the operator F. Bibliography: 23 titles.

  19. Detection of Differential Item Functioning in Multiple Groups.

    ERIC Educational Resources Information Center

    Kim, Seock-Ho; And Others

    Detection of differential item functioning (DIF) is most often done between two groups of examinees under item response theory. It is sometimes important, however, to determine whether DIF is present in more than two groups. A method is presented for the detection of DIF in multiple groups. The method, the Q(sub j) statistic, is closely related to…

  20. Differential Item Functioning on Two Tests of EFL Proficiency.

    ERIC Educational Resources Information Center

    Ryan, Katherine E.; Bachman, Lyle F.

    1992-01-01

    The extent to which items from the Test of English as a Foreign Language and the First Certificate in English function differently for test-takers of equal ability from different native language and curricular backgrounds was investigated. Results suggest a need for methods like logistic regression to examine nonuniform differential item…

  1. Detection of Differential Item Functioning Using the Lasso Approach

    ERIC Educational Resources Information Center

    Magis, David; Tuerlinckx, Francis; De Boeck, Paul

    2015-01-01

    This article proposes a novel approach to detect differential item functioning (DIF) among dichotomously scored items. Unlike standard DIF methods that perform an item-by-item analysis, we propose the "LR lasso DIF method": logistic regression (LR) model is formulated for all item responses. The model contains item-specific intercepts,…

  2. A differential equation for the zeros of bessel functions

    Microsoft Academic Search

    E. K. Ifantis; P. D. Siafarikas

    1985-01-01

    Let ?(v) be a positive zero of the ordinary Bessel function Jv(z) of order v. It is shown that for every v in the interval -1>v>? the function ?(v) satisfies the differential equation ?(v)=?(vv)(LvX(v)) where Lv is the diagonal operator LVen=1\\/n+en on an abstract Hilbert space H with the oYtRonormal basis en=1,2,… and x(v) is a normalized element in H.

  3. Differentiation

    NSDL National Science Digital Library

    2013-06-21

    In the five parts of this video, we define the derivative and then build a cribsheet of rules for expressing the slopes of simple functions and combinations of functions. These include the power rule, the chain rule, the product and quotient rules, and the rules for differentiating sinusoidal functions.

  4. Conservative management of accessory spleen torsion in children.

    PubMed

    Scirè, G; Zampieri, N; El-Dalati, G; Camoglio, F S

    2013-08-01

    Accessory spleen torsion is very rare condition especially in children. The aim of this study is to report the conservative treatment option. In April 2009 we observed a 10-year-old child affected by hereditary spherocytosis who reported acute abdominal pain without fever or vomiting. At hospitalization all blood tests were within normal value. Abdominal ultrasounds showed an increase in spleen volume and a solid round-shaped hypoechogenic formation with hyperechogenic areas in the lower pole without vascolarisation on color-Doppler scan. These findings suggested torsion of the accessory spleen. We opted for a conservative approach: analgesics on demand and antibiotics. After a week symptoms resolved spontaneously and patient was discharged in good health conditions. Follow-up ultrasound scans were performed at one week, three-six months and one year after hospitalization and showed a progressive reduction of the dimensions of the solid round-shaped formation. Accessory spleen torsion needs to be added to the differential diagnosis of cases of acute abdomen in children. Ultrasounds with eco-color-Doppler scans seem to be the best option for the diagnosis of such condition in the pediatric age since other diagnostic methods are more invasive and require sedation of patients. Once accessory spleen torsion is correctly diagnosed it is possible to opt for its conservative treatment. PMID:24051978

  5. Differential Item Functioning Detection with Latent Classes: How Accurately Can We Detect Who Is Responding Differentially?

    ERIC Educational Resources Information Center

    DeMars, Christine E.; Lau, Abigail

    2011-01-01

    There is a long history of differential item functioning (DIF) detection methods for known, manifest grouping variables, such as sex or ethnicity. But if the experiences or cognitive processes leading to DIF are not perfectly correlated with the manifest groups, it would be more informative to uncover the latent groups underlying DIF. The use of…

  6. Differential expression of functional nucleoside transporters in non-differentiated and differentiated human endothelial progenitor cells

    Microsoft Academic Search

    E. Guzmán-Gutiérrez; C. Sandoval; E. Nova; J. L. Castillo; J. C. Vera; L. Lamperti; B. Krause; C. Salomón; C. Sepúlveda; C. Aguayo; L. Sobrevia

    2010-01-01

    Extracellular adenosine removal is via human equilibrative nucleoside transporters 1 (hENT1) and 2 (hENT2) in the endothelium, thus regulating adenosine-induced revascularization and angiogenesis. Since human endothelial progenitor cells (hEPCs) promote revascularization, we hypothesize differential expression of nucleoside transporters in hEPCs. hEPCs were cultured 3 (hEPC-3d) or 14 (hEPC-14d) days. RT-PCR for prominin 1, CD34, octamer-4, kinase insert domain receptor, oxidized

  7. 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

  8. 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

  9. Differentiable but exact formulation of density-functional theory

    SciTech Connect

    Kvaal, Simen, E-mail: simen.kvaal@kjemi.uio.no; Ekström, Ulf; Helgaker, Trygve [Centre for Theoretical and Computational Chemistry, Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, N-0315 Oslo (Norway)] [Centre for Theoretical and Computational Chemistry, Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, N-0315 Oslo (Norway); Teale, Andrew M. [Centre for Theoretical and Computational Chemistry, Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, N-0315 Oslo (Norway) [Centre for Theoretical and Computational Chemistry, Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, N-0315 Oslo (Norway); School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

    2014-05-14

    The universal density functional F of density-functional theory is a complicated and ill-behaved function of the density—in particular, F is not differentiable, making many formal manipulations more complicated. While F has been well characterized in terms of convex analysis as forming a conjugate pair (E, F) with the ground-state energy E via the Hohenberg–Kohn and Lieb variation principles, F is nondifferentiable and subdifferentiable only on a small (but dense) subset of its domain. In this article, we apply a tool from convex analysis, Moreau–Yosida regularization, to construct, for any ? > 0, pairs of conjugate functionals ({sup ?}E, {sup ?}F) that converge to (E, F) pointwise everywhere as ? ? 0{sup +}, and such that {sup ?}F is (Fréchet) differentiable. For technical reasons, we limit our attention to molecular electronic systems in a finite but large box. It is noteworthy that no information is lost in the Moreau–Yosida regularization: the physical ground-state energy E(v) is exactly recoverable from the regularized ground-state energy {sup ?}E(v) in a simple way. All concepts and results pertaining to the original (E, F) pair have direct counterparts in results for ({sup ?}E, {sup ?}F). The Moreau–Yosida regularization therefore allows for an exact, differentiable formulation of density-functional theory. In particular, taking advantage of the differentiability of {sup ?}F, a rigorous formulation of Kohn–Sham theory is presented that does not suffer from the noninteracting representability problem in standard Kohn–Sham theory.

  10. Rax regulates hypothalamic tanycyte differentiation and barrier function in mice.

    PubMed

    Miranda-Angulo, Ana L; Byerly, Mardi S; Mesa, Janny; Wang, Hong; Blackshaw, Seth

    2014-03-01

    The wall of the ventral third ventricle is composed of two distinct cell populations: tanycytes and ependymal cells. Tanycytes regulate many aspects of hypothalamic physiology, but little is known about the transcriptional network that regulates their development and function. We observed that the retina and anterior neural fold homeobox transcription factor (Rax) is selectively expressed in hypothalamic tanycytes, and showed a complementary pattern of expression to markers of hypothalamic ependymal cells, such as Rarres2 (retinoic acid receptor responder [tazarotene induced] 2). To determine whether Rax controls tanycyte differentiation and function, we generated Rax haploinsufficient mice and examined their cellular and molecular phenotype in adulthood. These mice appeared grossly normal, but careful examination revealed a thinning of the third ventricular wall and reduction of both tanycyte and ependymal markers. These experiments show that Rax is required for hypothalamic tanycyte and ependymal cell differentiation. Rax haploinsufficiency also resulted in the ectopic presence of ependymal cells in the ?2 tanycytic zone, where few ependymal cells are normally found, suggesting that Rax is selectively required for ?2 tanycyte differentiation. These changes in the ventricular wall were associated with reduced diffusion of Evans Blue tracer from the ventricle to the hypothalamic parenchyma, with no apparent repercussion on the gross anatomical or behavioral phenotype of these mice. In conclusion, we have provided evidence that Rax is required for the normal differentiation and patterning of hypothalamic tanycytes and ependymal cells, as well as for maintenance of the cerebrospinal fluid-hypothalamus barrier. PMID:23939786

  11. Application of New Triangular Functions to Nonlinear Partial Differential Equations

    NASA Astrophysics Data System (ADS)

    Abdel-Salam, Emad A.-B.; Kaya, Dogan

    2009-02-01

    The results of some new research on a new class of triangular functions that unite the characteristics of the classical triangular functions are presented. Taking into consideration the great role played by triangular functions in geometry and physics, it is possible to expect that the new theory of the triangular functions will bring new results and interpretations in mathematics, biology, physics and cosmology. New traveling wave solutions of some nonlinear partial differential equations are obtained in a unified way. The main idea of this method is to express the solutions of these equations as a polynomial in the solution of the Riccati equation that satisfy the symmetrical triangular Fibonacci functions. We apply this method to the combined Korteweg-de Vries (KdV) and modified KdV (mKdV) equations, the generalized Kawahara equation, Ito's 5th-order mKdV equation and Ito's 7th-order mKdV equation.

  12. 21 CFR 890.3910 - Wheelchair accessory.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3910 Wheelchair accessory. (a) Identification. A...

  13. 21 CFR 890.3910 - Wheelchair accessory.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3910 Wheelchair accessory. (a) Identification. A...

  14. 21 CFR 890.3910 - Wheelchair accessory.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3910 Wheelchair accessory. (a) Identification....

  15. 21 CFR 890.3910 - Wheelchair accessory.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3910 Wheelchair accessory. (a) Identification....

  16. 21 CFR 890.3910 - Wheelchair accessory.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3910 Wheelchair accessory. (a) Identification....

  17. Inorganic arsenic impairs differentiation and functions of human dendritic cells

    SciTech Connect

    Macoch, Mélinda; Morzadec, Claudie [UMR INSERM U1085, Institut de Recherche sur la Santé, l'Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France)] [UMR INSERM U1085, Institut de Recherche sur la Santé, l'Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France); Fardel, Olivier [UMR INSERM U1085, Institut de Recherche sur la Santé, l'Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France) [UMR INSERM U1085, Institut de Recherche sur la Santé, l'Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France); Pôle Biologie, Centre Hospitalier Universitaire (CHU) Rennes, 2 rue Henri Le Guilloux, 35033 Rennes (France); Vernhet, Laurent, E-mail: laurent.vernhet@univ-rennes1.fr [UMR INSERM U1085, Institut de Recherche sur la Santé, l'Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France)] [UMR INSERM U1085, Institut de Recherche sur la Santé, l'Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France)

    2013-01-15

    Experimental studies have demonstrated that the antileukemic trivalent inorganic arsenic prevents the development of severe pro-inflammatory diseases mediated by excessive Th1 and Th17 cell responses. Differentiation of Th1 and Th17 subsets is mainly regulated by interleukins (ILs) secreted from dendritic cells (DCs) and the ability of inorganic arsenic to impair interferon-? and IL-17 secretion by interfering with the physiology of DCs is unknown. In the present study, we demonstrate that high concentrations of sodium arsenite (As(III), 1–2 ?M) clinically achievable in plasma of arsenic-treated patients, block differentiation of human peripheral blood monocytes into immature DCs (iDCs) by inducing their necrosis. Differentiation of monocytes in the presence of non-cytotoxic concentrations of As(III) (0.1 to 0.5 ?M) only slightly impacts endocytotic activity of iDCs or expression of co-stimulatory molecules in cells activated with lipopolysaccharide. However, this differentiation in the presence of As(III) strongly represses secretion of IL-12p70 and IL-23, two major regulators of Th1 and Th17 activities, from iDCs stimulated with different toll-like receptor (TLR) agonists in metalloid-free medium. Such As(III)-exposed DCs also exhibit reduced mRNA levels of IL12A and/or IL12B genes when activated with TLR agonists. Finally, differentiation of monocytes with non-cytotoxic concentrations of As(III) subsequently reduces the ability of activated DCs to stimulate the release of interferon-? and IL-17 from Th cells. In conclusion, our results demonstrate that clinically relevant concentrations of inorganic arsenic markedly impair in vitro differentiation and functions of DCs, which may contribute to the putative beneficial effects of the metalloid towards inflammatory autoimmune diseases. Highlights: ? Inorganic arsenic impairs differentiation and functions of human dendritic cells (DCs) ? Arsenite (> 1 ?M) blocks differentiation of dendritic cells by inducing necrosis ? Arsenite (0.1 to 0.5 ?M) slightly reduces endocytotic activity of immature DCs ? Arsenite (0.1 to 0.5 ?M) represses expression of IL-12p70 and IL-23 in activated DCs ? Arsenite (0.1 to 0.5 ?M) reduces the ability of DCs to activate human T lymphocytes.

  18. Advanced Accessory Power Supply Topologies

    SciTech Connect

    Marlino, L.D.

    2010-06-15

    This Cooperative Research and Development Agreement (CRADA) began December 8, 2000 and ended September 30, 2009. The total funding provided by the Participant (General Motors Advanced Technology Vehicles [GM]) during the course of the CRADA totaled $1.2M enabling the Contractor (UT-Battelle, LLC [Oak Ridge National Laboratory, a.k.a. ORNL]) to contribute significantly to the joint project. The initial task was to work with GM on the feasibility of developing their conceptual approach of modifying major components of the existing traction inverter/drive to develop low cost, robust, accessory power. Two alternate methods for implementation were suggested by ORNL and both were proven successful through simulations and then extensive testing of prototypes designed and fabricated during the project. This validated the GM overall concept. Moreover, three joint U.S. patents were issued and subsequently licensed by GM. After successfully fulfilling the initial objective, the direction and duration of the CRADA was modified and GM provided funding for two additional tasks. The first new task was to provide the basic development for implementing a cascaded inverter technology into hybrid vehicles (including plug-in hybrid, fuel cell, and electric). The second new task was to continue the basic development for implementing inverter and converter topologies and new technology assessments for hybrid vehicle applications. Additionally, this task was to address the use of high temperature components in drive systems. Under this CRADA, ORNL conducted further research based on GM’s idea of using the motor magnetic core and windings to produce bidirectional accessory power supply that is nongalvanically coupled to the terminals of the high voltage dc-link battery of hybrid vehicles. In order not to interfere with the motor’s torque, ORNL suggested to use the zero-sequence, highfrequency harmonics carried by the main fundamental motor current for producing the accessory power. Two studies were conducted at ORNL. One was to put an additional winding in the motor slots to magnetically link with the high frequency of the controllable zero-sequence stator currents that do not produce any zero-sequence harmonic torques. The second approach was to utilize the corners of the square stator punching for the high-frequency transformers of the dc/dc inverter. Both approaches were successful. This CRADA validated the feasibility of GM’s desire to use the motor’s magnetic core and windings to produce bidirectional accessory power supply. Three joint U.S. patents with GM were issued to ORNL and GM by the U.S. Patent Office for the research results produced by this CRADA.

  19. Glucose Metabolism Regulates T Cell Activation, Differentiation, and Functions

    PubMed Central

    Palmer, Clovis S.; Ostrowski, Matias; Balderson, Brad; Christian, Nicole; Crowe, Suzanne M.

    2014-01-01

    The adaptive immune system is equipped to eliminate both tumors and pathogenic microorganisms. It requires a series of complex and coordinated signals to drive the activation, proliferation, and differentiation of appropriate T cell subsets. It is now established that changes in cellular activation are coupled to profound changes in cellular metabolism. In addition, emerging evidence now suggest that specific metabolic alterations associated with distinct T cell subsets may be ancillary to their differentiation and influential in their immune functions. The “Warburg effect” originally used to describe a phenomenon in which most cancer cells relied on aerobic glycolysis for their growth is a key process that sustain T cell activation and differentiation. Here, we review how different aspects of metabolism in T cells influence their functions, focusing on the emerging role of key regulators of glucose metabolism such as HIF-1?. A thorough understanding of the role of metabolism in T cell function could provide insights into mechanisms involved in inflammatory-mediated conditions, with the potential for developing novel therapeutic approaches to treat these diseases. PMID:25657648

  20. Hunting for eruption ages in accessory minerals

    NASA Astrophysics Data System (ADS)

    Vazquez, J. A.

    2012-12-01

    A primary goal in geochronology is to provide precise and accurate ages for tephras that serve as chronostratigraphic markers for constraining the timing and rates of volcanism, sedimentation, climate change, and catastrophic events in Earth history. Zircon remains the most versatile accessory mineral for dating silicic tephras due to its common preservation in distal pyroclastic deposits, as well as the robustness of its U-Pb and U-series systems even after host materials have been hydrothermally altered or weathered. Countless studies document that zircon may be complexly zoned in age due to inheritance, contamination, recycling of antecrysts, protracted crystallization in long-lived magma reservoirs, or any combination of these. Other accessory minerals such as allanite or chevkinite can retain similar records of protracted crystallization. If the goal is to date the durations of magmatic crystallization, differentiation, and/or magma residence, then these protracted chronologies within and between accessory minerals are a blessing. However, if the goal is to date the timing of eruption with high precision, i.e., absolute ages with millennial-scale uncertainties, then this age zoning is a curse. Observations from ion microprobe 238U-230Th dating of Pleistocene zircon and allanite provide insight into the record of near-eruption crystallization in accessory minerals and serve as a guide for high-precision whole-crystal dating. Although imprecise relative to conventional techniques, ion probe analysis allows high-spatial resolution 238U-230Th dating that can document multi-millennial age distributions at the crystal scale. Analysis of unpolished rims and continuous depth profiling of zircon from small and large volume eruptions (e.g., Coso, Mono Craters, Yellowstone) reveals that the final several micrometers of crystallization often yield ages that are indistinguishable from associated eruption ages from the 40Ar/39Ar or (U-Th)/He methods. Using this approach, we have derived relatively precise (± ~ 5%, 2?) U-Th isochron ages from the unpolished rims of pumice-derived allanite and zircon from late Pleistocene Wilson Creek Formation tephras in eastern California, whose ages are controversial and have been difficult to resolve via 40Ar/39Ar and radiocarbon dating. Allanite and zircon rims from Ashes 7-19 in the lower portion of Wilson Creek sediments yield stratigraphically consistent ages of ca. 27 ka to ca. 62 ka, with a minority of crystals identifiable as xenocrysts from early Mono Craters rhyolites. Model ages for the interiors of allanite crystals are mostly < 10 k.y. older than their rims. Tephra deposited during the geomagnetic excursion debated to be either the Mono Lake or Laschamp event yields a rim isochron age of ca. 41 ka. This age is indistinguishable from an independent age of 41 ka derived at the latter excursion's type locality in France (Singer et al., 2009) as well as from age-models for deep-sea sediments. The results are in excellent agreement with a previously determined chronology derived from magnetostratigraphy (Zimmerman et al., 2006). Refs: Singer et al., 2009, EPSL 286: 80-88; Zimmerman et al., 2006, EPSL 252: 94-106

  1. 19 CFR 10.920 - Accessories, spare parts, or tools.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... false Accessories, spare parts, or tools. 10.920 Section 10.920 Customs...10.920 Accessories, spare parts, or tools. (a) General. Accessories, spare parts, or tools that are delivered with a good and...

  2. 19 CFR 10.537 - Accessories, spare parts, or tools.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Accessories, spare parts, or tools. 10.537 Section 10.537 Customs Duties... § 10.537 Accessories, spare parts, or tools. Accessories, spare parts, or tools that are delivered with a good and that...

  3. 19 CFR 10.920 - Accessories, spare parts, or tools.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... false Accessories, spare parts, or tools. 10.920 Section 10.920 Customs...10.920 Accessories, spare parts, or tools. (a) General. Accessories, spare parts, or tools that are delivered with a good and...

  4. 19 CFR 10.537 - Accessories, spare parts, or tools.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 false Accessories, spare parts, or tools. 10.537 Section 10.537 Customs Duties... § 10.537 Accessories, spare parts, or tools. Accessories, spare parts, or tools that are delivered with a good and that...

  5. 19 CFR 10.1020 - Accessories, spare parts, or tools.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... false Accessories, spare parts, or tools. 10.1020 Section 10.1020 Customs...10.1020 Accessories, spare parts, or tools. (a) General. Accessories, spare parts, or tools that are delivered with a good and...

  6. 19 CFR 10.537 - Accessories, spare parts, or tools.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Accessories, spare parts, or tools. 10.537 Section 10.537 Customs Duties... § 10.537 Accessories, spare parts, or tools. Accessories, spare parts, or tools that are delivered with a good and that...

  7. 19 CFR 10.1020 - Accessories, spare parts, or tools.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... false Accessories, spare parts, or tools. 10.1020 Section 10.1020 Customs...10.1020 Accessories, spare parts, or tools. (a) General. Accessories, spare parts, or tools that are delivered with a good and...

  8. 19 CFR 10.537 - Accessories, spare parts, or tools.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Accessories, spare parts, or tools. 10.537 Section 10.537 Customs Duties... § 10.537 Accessories, spare parts, or tools. Accessories, spare parts, or tools that are delivered with a good and that...

  9. 19 CFR 10.920 - Accessories, spare parts, or tools.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... false Accessories, spare parts, or tools. 10.920 Section 10.920 Customs...10.920 Accessories, spare parts, or tools. (a) General. Accessories, spare parts, or tools that are delivered with a good and...

  10. 14 CFR 23.1192 - Engine accessory compartment diaphragm.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...false Engine accessory compartment diaphragm. 23.1192...Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For...from the engine accessory compartment by a diaphragm that...

  11. 14 CFR 23.1192 - Engine accessory compartment diaphragm.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...false Engine accessory compartment diaphragm. 23.1192...Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For...from the engine accessory compartment by a diaphragm that...

  12. 14 CFR 23.1192 - Engine accessory compartment diaphragm.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...false Engine accessory compartment diaphragm. 23.1192...Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For...from the engine accessory compartment by a diaphragm that...

  13. 14 CFR 23.1192 - Engine accessory compartment diaphragm.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...false Engine accessory compartment diaphragm. 23.1192...Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For...from the engine accessory compartment by a diaphragm that...

  14. 14 CFR 23.1192 - Engine accessory compartment diaphragm.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...false Engine accessory compartment diaphragm. 23.1192...Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For...from the engine accessory compartment by a diaphragm that...

  15. Control of functional differential equations to target sets in function space

    NASA Technical Reports Server (NTRS)

    Banks, H. T.; Kent, G. A.

    1971-01-01

    Optimal control of systems governed by functional differential equations of retarded and neutral type is considered. Problems with function space initial and terminal manifolds are investigated. Existence of optimal controls, regularity, and bang-bang properties are discussed. Necessary and sufficient conditions are derived, and several solved examples which illustrate the theory are presented.

  16. Characterization of a Lolium multiflorum Accessory Chromosome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accessory chromosomes, also called B-chromosomes, have been reported in more than 1300 species of plants. Accessory chromosomes show numerical polymorphism and when present in high number, are known to negatively affect the growth and vigor of the plants, while in low numbers they may be beneficial...

  17. Neutrophil extracellular traps promote differentiation and function of fibroblasts.

    PubMed

    Chrysanthopoulou, Akrivi; Mitroulis, Ioannis; Apostolidou, Eirini; Arelaki, Stella; Mikroulis, Dimitrios; Konstantinidis, Theocharis; Sivridis, Efthimios; Koffa, Maria; Giatromanolaki, Alexandra; Boumpas, Dimitrios T; Ritis, Konstantinos; Kambas, Konstantinos

    2014-07-01

    Neutrophil activation by inflammatory stimuli and the release of extracellular chromatin structures (neutrophil extracellular traps - NETs) have been implicated in inflammatory disorders. Herein, we demonstrate that NETs released by neutrophils treated either with fibrosis-related agents, such as cigarette smoke, magnesium silicate, bleomycin, or with generic NET inducers, such as phorbol 12-myristate 13-acetate, induced activation of lung fibroblasts (LFs) and differentiation into myofibroblast (MF) phenotype. Interestingly, the aforementioned agents or IL-17 (a primary initiator of inflammation/fibrosis) had no direct effect on LF activation and differentiation. MFs treated with NETs demonstrated increased connective tissue growth factor expression, collagen production, and proliferation/migration. These fibrotic effects were significantly decreased after degradation of NETs with DNase1, heparin or myeloperoxidase inhibitor, indicating the key role of NET-derived components in LF differentiation and function. Furthermore, IL-17 was expressed in NETs and promoted the fibrotic activity of differentiated LFs but not their differentiation, suggesting that priming by DNA and histones is essential for IL-17-driven fibrosis. Additionally, autophagy was identified as the orchestrator of NET formation, as shown by inhibition studies using bafilomycin A1 or wortmannin. The above findings were further supported by the detection of NETs in close proximity to alpha-smooth muscle actin (?-SMA)-expressing fibroblasts in biopsies from patients with fibrotic interstitial lung disease or from skin scar tissue. Together, these data suggest that both autophagy and NETs are involved not only in inflammation but also in the ensuing fibrosis and thus may represent potential therapeutic targets in human fibrotic diseases. PMID:24740698

  18. 21 CFR 864.3600 - Microscopes and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Pathology Instrumentation and Accessories § 864.3600 Microscopes and accessories. (a)...

  19. 21 CFR 864.3600 - Microscopes and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Pathology Instrumentation and Accessories § 864.3600 Microscopes and accessories. (a)...

  20. 21 CFR 864.3600 - Microscopes and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Pathology Instrumentation and Accessories § 864.3600 Microscopes and accessories. (a)...

  1. 21 CFR 864.3600 - Microscopes and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Pathology Instrumentation and Accessories § 864.3600 Microscopes and accessories. (a)...

  2. An Effect Size Measure for Raju's Differential Functioning for Items and Tests

    ERIC Educational Resources Information Center

    Wright, Keith D.; Oshima, T. C.

    2015-01-01

    This study established an effect size measure for differential functioning for items and tests' noncompensatory differential item functioning (NCDIF). The Mantel-Haenszel parameter served as the benchmark for developing NCDIF's effect size measure for reporting moderate and large differential item functioning in test items. The effect size of…

  3. Role of PPAR? in the Differentiation and Function of Neurons

    PubMed Central

    Quintanilla, Rodrigo A.; Utreras, Elias; Cabezas-Opazo, Fabián A.

    2014-01-01

    Neuronal processes (neurites and axons) have an important role in brain cells communication and, generally, they are damaged in neurodegenerative diseases. Recent evidence has showed that the activation of PPAR? pathway promoted neuronal differentiation and axon polarity. In addition, activation of PPAR? using thiazolidinediones (TZDs) prevented neurodegeneration by reducing neuronal death, improving mitochondrial function, and decreasing neuroinflammation in neuropathic pain. In this review, we will discuss important evidence that supports a possible role of PPAR? in neuronal development, improvement of neuronal health, and pain signaling. Therefore, activation of PPAR? is a potential target with therapeutic applications against neurodegenerative disorders, brain injury, and pain regulation. PMID:25246934

  4. Accessory tragus: a dentist's perspective

    PubMed Central

    Khandelwal, Vishal; Banda, Naveen Reddy; Nayak, Ullal Anand; Banda, Vanaja Reddy

    2013-01-01

    Accessory tragus (AT) also referred as preauricular tag is a rudimentary tag of ear tissue This paper presents two specific cases: one hereditary and another sporadic case of AT. A general clinical description of AT, its associated syndromes, embryology aetiopathogenesis and management is discussed. A dentist can play an important role in spotting the AT during their head and neck examination. The presence of this defect can be correlated to other congenital defects of first branchial arch. On recognising its occurrence, the dentist can refer to a specialist for thorough investigation management. A dentist can play a vital role in encouraging and counselling the parents for the correction of such defects as it improves the aesthetics of the face. Usually, children with these defects are often targets of teasing by peers. PMID:23761605

  5. Preparation, Functional Characterization, and NMR Studies of Human KCNE1, a Voltage-Gated Potassium Channel Accessory Subunit Associated With Deafness and Long QT Syndrome†

    PubMed Central

    Tian, Changlin; Vanoye, Carlos G.; Kang, Congbao; Welch, Richard C.; Kim, Hak Jun; George, Alfred L.; Sanders, Charles R.

    2008-01-01

    KCNE1, also known as minK, is a member of the KCNE family of membrane proteins that modulate the function of KCNQ1 and certain other voltage-gated potassium channels (KV). Mutations in human KCNE1 cause congenital deafness and congenital long QT syndrome, an inherited predisposition to potentially life-threatening cardiac arrhythmias. Although its modulation of KCNQ1 function has been extensively characterized, many questions remain regarding KCNE1's structure and location within the channel complex. In this study KCNE1 was overexpressed in E. coli and purified. Micellar solutions of the protein were then microinjected into Xenopus oocytes expressing KCNQ1 channels, followed by electrophysiological recordings to test whether recombinant KCNE1 can co-assemble with the channel. Native-like modulation of channel properties was observed following injection of KCNE1 in lysomyristoylphosphatidylglycerol (LMPG) micelles, indicating that KCNE1 is not irreversibly misfolded and that LMPG is able to act as a vehicle for delivering membrane proteins into the membranes of viable cells. 1H,15N-TROSY NMR experiments indicated that LMPG micelles are well-suited for structural studies of KCNE1, leading to assignment of its backbone resonances and to relaxation studies. The chemical shift data confirmed that KCNE1's secondary structure includes several ?-helices and demonstrated that its distal C-terminus is disordered. Surprisingly, for KCNE1 in LMPG micelles there appears to be a break in ?-helicity at sites 59?61, near the middle of the transmembrane segment, a feature that is accompanied by increased local backbone mobility. Given that this segment overlaps with sites 57?59, which are known to play a critical role in modulating KCNQ1 channel activation kinetics, this unusual structural feature is likely of considerable functional relevance. PMID:17892302

  6. Reduced susceptibility of Staphylococcus aureus to vancomycin and platelet microbicidal protein correlates with defective autolysis and loss of accessory gene regulator (agr) function.

    PubMed

    Sakoulas, George; Eliopoulos, George M; Fowler, Vance G; Moellering, Robert C; Novick, Richard P; Lucindo, Natalie; Yeaman, Michael R; Bayer, Arnold S

    2005-07-01

    Loss of agr function, vancomycin exposure, and abnormal autolysis have been linked with both development of the GISA phenotype and low-level resistance in vitro to thrombin-induced platelet microbicidal proteins (tPMPs). We examined the potential in vitro interrelationships among these parameters in well-characterized, isogenic laboratory-derived and clinical Staphylococcus aureus isolates. The laboratory-derived S. aureus strains included RN6607 (agrII-positive parent) and RN6607V (vancomycin-passaged variant; hetero-GISA), RN9120 (RN6607 agr::tetM; agr II knockout parent), RN9120V (vancomycin-passaged variant), and RN9120-GISA (vancomycin passaged, GISA). Two serial isolates from a vancomycin-treated patient with recalcitrant, methicillin-resistant S. aureus (MRSA) endocarditis were also studied: A5937 (agrII-positive initial isolate) and A5940 (agrII-defective/hetero-GISA isolate obtained after prolonged vancomycin administration). In vitro tPMP susceptibility phenotypes were assessed after exposure of strains to either 1 or 2 mug/ml. Triton X-100- and vancomycin-induced lysis profiles were determined spectrophotometrically. For agrII-intact strain RN6607, vancomycin exposure in vitro was associated with modest increases in vancomycin MICs and reduced killing by tPMP, but no change in lysis profiles. In contrast, vancomycin exposure of agrII-negative RN9120 yielded a hetero-GISA phenotype and was associated with defects in lysis and reduced in vitro killing by tPMP. In the clinical isolates, loss of agrII function during prolonged vancomycin therapy was accompanied by emergence of the hetero-GISA phenotype and reduced tPMP killing, with no significant change in lysis profiles. An association was identified between loss of agrII function and the emergence of hetero-GISA phenotype during either in vitro or in vivo vancomycin exposure. In vitro, these events were associated with defective lysis and reduced susceptibility to tPMP. The precise mechanism(s) underlying these findings is the subject of current investigations. PMID:15980337

  7. Requirement for functional BK channels in maintaining oscillation in venomotor tone revealed by species differences in expression of the ?1 accessory subunits

    PubMed Central

    Xu, Hui; Kandlikar, Sachin S; Westcott, Erika B; Fink, Gregory D; Galligan, James J

    2011-01-01

    We determined the possible role of large-conductance Ca2+-activated K+ (BK) channels in regulation of venous tone in small capacitance veins and blood pressure. In rat mesenteric venous smooth muscle cells (MV SMC), BK channel ?- and ?1-subunits were co-expressed, unitary BK currents were detected, and single channel currents were sensitive to voltage and [Ca2+]i. Rat MV SMCs displayed Ca2+ sparks and iberiotoxin (IBTX)-sensitive spontaneous transient outward currents (STOCs). Under resting conditions in vitro, rat MV exhibited nifedipine-sensitive spontaneous oscillatory constrictions. Blockade of BK channels by paxilline and Ca2+ sparks by ryanodine constricted rat MV. Nifedipine caused venodilation and blocked paxilline-, KCl (20 mM) and BayK 8644-induced contraction. Acute inhibition of BK channels with IBTX in vivo increased blood pressure and reduced venous capacitance, measured as an increase in mean circulatory filling pressure in conscious rats. BK channel ?-subunits and L-type Ca2+ channel ?1-C subunits are expressed in murine MV. However, these channels are not functional as murine MV lacked nifedipine-sensitive basal tone and rhythmic constrictions. Murine MV were also insensitive to paxilline, ryanodine, KCl and BayK8644, consistent with our previous studies showing that murine MV do not have BK ?1-subunits. These data show that not only there are species-dependent properties in ion channel control of venomotor tone, but also that BK channels are required for rhythmic oscillations in venous tone. PMID:21885988

  8. Perioperative Identification of an Accessory Fissure of the Right Lung

    PubMed Central

    Taverne, Yannick; Kleinrensink, Gert-Jan; de Rooij, Peter

    2015-01-01

    Anatomical variations of lungs are common in clinical practice; however, they are sometimes overlooked in routine imaging. Surgical anatomy of the lung is complex and many variations are known to occur. A defective pulmonary development gives rise to variations in lobes and fissures. Morphological presentation is of clinical importance and profound knowledge of the organogenesis and functional anatomy is imperative for the interpretation and evaluation of lung pathophysiology and subsequent surgical intervention. However, appreciating them on radiographs and CT scans is difficult and they are therefore often either not identified or completely misinterpreted. As presented in this case report, an accessory fissure separating the superior segment of the right lower lobe from its native lobe was seen perioperatively and could only retrospectively be defined on X-rays and CT scan. It is imperative to keep in mind that accessory fissures can be missed on imaging studies and thus can make the surgical procedure more challenging. PMID:26185701

  9. Assessing Gender-Related Differential Item Functioning and Predictive Validity with the Institutional Integration Scale

    ERIC Educational Resources Information Center

    Baker, Becca A.; Caison, Amy L.; Meade, Adam W.

    2007-01-01

    This study examined the gender-related differential predictive validity of five subscales of the Institutional Integration Scale (IIS) with regard to college student withdrawal. Differential functioning of the IIS across genders was assessed using an item response theory (IRT)-based framework of differential item and test functioning. The results…

  10. Honokiol inhibits osteoclast differentiation and function in vitro.

    PubMed

    Hasegawa, Shin-Ichi; Yonezawa, Takayuki; Ahn, Jae-Yong; Cha, Byung-Yoon; Teruya, Toshiaki; Takami, Masamichi; Yagasaki, Kazumi; Nagai, Kazuo; Woo, Je-Tae

    2010-01-01

    Honokiol, a neolignan, is a physiologically active component of kouboku (Magnolia obovata), a herb used in traditional Chinese medicine. This study investigated the effects of honokiol on the differentiation and function of osteoclasts induced by receptor activator of nuclear factor-kappaB ligand (RANKL). Honokiol markedly inhibited RANKL-induced tartrate-resistant acid phosphatase (TRAP) activity and the formation of TRAP-positive multinucleated cells in both bone marrow-derived monocytes and RAW264 cells. In experiments to elucidate its mechanism of action, honokiol was found to suppress RANKL-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK). The RANKL-induced expressions of c-Fos and nuclear factor of activated T cells-c1 (NFATc1), which are crucial transcriptional factors for osteoclastogenesis, were also reduced by treatment with honokiol. Furthermore, honokiol induced disruption of the actin rings in mature osteoclasts (mOCs) without affecting the cell viability and suppressed osteoclastic pit formation on dentin slices. Taken together, these results suggest that honokiol inhibits osteoclast differentiation by suppressing the activation of MAPKs (p38 MAPK, ERK and JNK), decreasing the expressions of c-Fos and NFATc1, and attenuates bone resorption by disrupting the actin rings in mOCs. Therefore, honokiol could prove useful for the treatment of bone diseases associated with excessive bone resorption. PMID:20190414

  11. Modifying Measures Based on Differential Item Functioning (DIF) Impact Analyses

    PubMed Central

    Teresi, Jeanne A.; Ramirez, Mildred; Jones, Richard N.; Choi, Seung; Crane, Paul K.

    2014-01-01

    Objectives Measure modification can impact comparability of scores across groups and settings. Changes in items can affect the percent admitting to a symptom. Methods Using item response theory (IRT) methods, well-calibrated items can be used interchangeably, and the exact same item does not have to be administered to each respondent, theoretically permitting wider latitude in terms of modification. Results Recommendations regarding modifications vary, depending on the use of the measure. In the context of research, adjustments can be made at the analytic level by freeing and fixing parameters based on findings of differential item functioning (DIF). The consequences of DIF for clinical decision making depend on whether or not the patient’s performance level approaches the scale decision cutpoint. High-stakes testing may require item removal or separate calibrations to ensure accurate assessment. Discussion Guidelines for modification based on DIF analyses and illustrations of the impact of adjustments are presented. PMID:22422759

  12. A Statistical Test for Differential Item Pair Functioning.

    PubMed

    Bechger, Timo M; Maris, Gunter

    2015-06-01

    This paper presents an IRT-based statistical test for differential item functioning (DIF). The test is developed for items conforming to the Rasch (Probabilistic models for some intelligence and attainment tests, The Danish Institute of Educational Research, Copenhagen, 1960) model but we will outline its extension to more complex IRT models. Its difference from the existing procedures is that DIF is defined in terms of the relative difficulties of pairs of items and not in terms of the difficulties of individual items. The argument is that the difficulty of an item is not identified from the observations, whereas the relative difficulties are. This leads to a test that is closely related to Lord's (Applications of item response theory to practical testing problems, Erlbaum, Hillsdale, 1980) test for item DIF albeit with a different and more correct interpretation. Illustrations with real and simulated data are provided. PMID:25223228

  13. Differential regulation of cell functions by CSD peptide subdomains

    PubMed Central

    2013-01-01

    Background In fibrotic lung diseases, expression of caveolin-1 is decreased in fibroblasts and monocytes. The effects of this deficiency are reversed by treating cells or animals with the caveolin-1 scaffolding domain peptide (CSD, amino acids 82–101 of caveolin-1) which compensates for the lack of caveolin-1. Here we compare the function of CSD subdomains (Cav-A, Cav-B, Cav-C, Cav-AB, and Cav-BC) and mutated versions of CSD (F92A and T90A/T91A/F92A). Methods Migration toward the chemokine CXCL12 and the associated expression of F-actin, CXCR4, and pSmad 2/3 were studied in monocytes from healthy donors and SSc patients. Fibrocyte differentiation was studied using PBMC from healthy donors and SSc patients. Collagen I secretion and signaling were studied in fibroblasts derived from the lung tissue of healthy subjects and SSc patients. Results Cav-BC and CSD at concentrations as low as 0.01 ?M inhibited the hypermigration of SSc monocytes and TGF?-activated Normal monocytes and the differentiation into fibrocytes of SSc and Normal monocytes. While CSD also inhibited the migration of poorly migrating Normal monocytes, Cav-A (and other subdomains to a lesser extent) promoted the migration of Normal monocytes while inhibiting the hypermigration of TGF?-activated Normal monocytes. The effects of versions of CSD on migration may be mediated in part via their effects on CXCR4, F-actin, and pSmad 2/3 expression. Cav-BC was as effective as CSD in inhibiting fibroblast collagen I and ASMA expression and MEK/ERK signaling. Cav-C and Cav-AB also inhibited collagen I expression, but in many cases did not affect ASMA or MEK/ERK. Cav-A increased collagen I expression in scleroderma lung fibroblasts. Full effects on fibroblasts of versions of CSD required 5 ?M peptide. Conclusions Cav-BC retains most of the anti-fibrotic functions of CSD; Cav-A exhibits certain pro-fibrotic functions. Results obtained with subdomains and mutated versions of CSD further suggest that the critical functional residues in CSD depend on the cell type and readout being studied. Monocytes may be more sensitive to versions of CSD than fibroblasts and endothelial cells because the baseline level of caveolin-1 in monocytes is much lower than in these other cell types. PMID:24011378

  14. Melanocortin receptor accessory proteins in adrenal disease and obesity

    PubMed Central

    Jackson, David S.; Ramachandrappa, Shwetha; Clark, Adrian J.; Chan, Li F.

    2015-01-01

    Melanocortin receptor accessory proteins (MRAPs) are regulators of the melanocortin receptor family. MRAP is an essential accessory factor for the functional expression of the MC2R/ACTH receptor. The importance of MRAP in adrenal gland physiology is demonstrated by the clinical condition familial glucocorticoid deficiency type 2. The role of its paralog melanocortin-2-receptor accessory protein 2 (MRAP2), which is predominantly expressed in the hypothalamus including the paraventricular nucleus, has recently been linked to mammalian obesity. Whole body deletion and targeted brain specific deletion of the Mrap2 gene result in severe obesity in mice. Interestingly, Mrap2 complete knockout (KO) mice have increased body weight without detectable changes to food intake or energy expenditure. Rare heterozygous variants of MRAP2 have been found in humans with severe, early-onset obesity. In vitro data have shown that Mrap2 interaction with the melanocortin-4-receptor (Mc4r) affects receptor signaling. However, the mechanism by which Mrap2 regulates body weight in vivo is not fully understood and differences between the phenotypes of Mrap2 and Mc4r KO mice may point toward Mc4r independent mechanisms.

  15. Building the blocks of executive functioning: differentiating early developing processes contributing to executive functioning skills.

    PubMed

    Mandell, Dorothy J; Ward, Sarah E

    2011-12-01

    The neural processes that underlie executive function begin to develop in infancy. However, it is unclear how the behavior manifested by these processes are related or if they can be differentiated early in development. This study seeks to examine early emerging executive functioning skills in monkeys (Macaca fascicularis) by using an error analysis approach where traditional measures of the tasks, as well as identification of major error patterns are related. Results show that during the infancy and early juvenile period, two processes that help support set-maintenance could be differentiated: modulation of responses to novelty and persistence despite negative feedback. The results suggest that these two aspects of set-maintenance were largely independent. Modulation of responses to novelty was most prominent in the infancy and early juvenile period. The ability to persist with a response set despite negative feedback emerged in the early juvenile period and was related to task performance until the end of the study. PMID:21563178

  16. Generating differential equations satisfied by products of functions

    Microsoft Academic Search

    Kwok Chiu Chung

    2001-01-01

    Based on the coefficients of two homogeneous linear differential equations, a method is proposed to construct a third homogeneous linear differential equations which is satisfied by all products of the form uv, where u and v satisfy, respectively, the first and the second given differential equation. The method was used recently in the computation of rapidly oscillatory integrals with kernels

  17. Accessory spleen in the pelvis: A case report

    PubMed Central

    Taskin, Mine Islimye; Baser, Banu Guleç; Adali, Ertan; Bulbul, Erdo?an; Uzgoren, Engin

    2015-01-01

    Introduction Accessory Spleen (AS) is a very rare entity and usually near the spleen’s hilum and in the tail of the pancreas. Pelvis reported as an atypical and a rare localization. AS may be formed during embryonic life, they rise from the left side of the dorsal mesogastrium as a result of imperfect fusion of separate splenic masses. Presentation of case We report a case of an AS presenting as an left adnexal mass in a middle-aged woman. Transvaginal ultrasonography and magnetic resonance imaging (MRI) revealed a left adnexial mass. Laparatomy was performed, and histological examination revealed that resected mass was splenic tissue. Discussion An AS is an incidental finding of no clinical significance in most patients. AS are generally determined during radiological investigations or during open or laparoscopic surgeries. When, the AS settle in the adnexal area; the differential diagnosis could include the causes of adnexal masses like enlarged lymph nodes, subserous fibroid, ovarian tumors, organized hematoma, tuboovarian abscess. Conclusion Althought pelvic accessory spleen is a rare condition, should be considered in the differential diagnosis of adnexal masses. PMID:25985297

  18. Singularly perturbed nonlinear boundary value problem for a kind of Volterra type functional differential equation

    Microsoft Academic Search

    Lu Shi-pin

    2003-01-01

    By employing the theory of differential inequality and some analysis methods, a nonlinear boundary value problem subject to\\u000a a general kind of second-order Volterra functional differential equation was considered first. Then, by constructing the right-side\\u000a layer function and the outer solution, a nonlinear boundary value problem subject to a kind of second-order Volterra functional\\u000a differential equation with a small parameter

  19. Activation of muscarinic acetylcholine receptors elevates intracellular Ca(2+) concentrations in accessory lobe neurons of the chick.

    PubMed

    Takahashi, Keita; Kitamura, Naoki; Suzuki, Yuki; Yamanaka, Yuko; Shinohara, Hikaru; Shibuya, Izumi

    2015-04-01

    Accessory lobes are protrusions located at the lateral sides of the spinal cord of chicks and it has been proposed that they play a role as a sensory organ for equilibrium during walking. We have reported that functional neurons exist in the accessory lobe. As there is histological evidence that synaptic terminals of cholinergic nerves exist near the somata of accessory lobe neurons, we examined the effects of acetylcholine on changes in intracellular Ca2+ concentrations ([Ca2+]i), as an index of cellular activities. Acetylcholine (0.1-100 µM) caused a transient rise in the [Ca2+]i. Acetylcholine-evoked [Ca2+]i rises were observed in the absence of extracellular Ca2+, and they were abolished in the presence of cyclopiazonic acid, an inhibitor of Ca2+-ATPase of intracellular Ca2+ stores or atropine, a muscarinic receptor antagonist. mRNAs coding M3 and M5 isoforms of the muscarinic receptors were detected in accessory lobes by the RT-PCR. These results indicate that chick accessory lobe neurons express functional muscarinic acetylcholine receptors, and that acetylcholine stimulates Ca2+ mobilization from intracellular Ca2+ stores, which elevates the [Ca2+]i in the somata of accessory lobe neurons, through activation of these receptors. Cholinergic synaptic transmission to the accessory lobe neurons may regulate some cellular functions through muscarinic receptors. PMID:25481714

  20. HOXB gene expression and function in differentiating purified hematopoietic progenitors.

    PubMed

    Giampaolo, A; Pelosi, E; Valtieri, M; Montesoro, E; Sterpetti, P; Samoggia, P; Camagna, A; Mastroberardino, G; Gabbianelli, M; Testa, U

    1995-05-01

    Intensive efforts have led to the development of methods for stringent purification of adult hematopoietic progenitor cells (HPCs), particularly from peripheral blood (PB). The purification procedure previously reported by our group (Science, 1990) provided a high HPC frequency, but yielded a low HPC recovery (< or = 5-10%). We therefore developed an improved purification methodology based on "potentiated" negative immunobead selection (Step IIIP) by addition of anti-CD45, -11a and -71 monoclonal antibodies (mAbs) to the previously utilized panel of mAbs. This simplified procedure consistently allows not only high level purification but also abundant recovery of early HPCs: the final Step IIIP cell population (0.95 x 10(6) cells/4 PB donors, mean value) features an 81% HPC frequency and a recovery of 45% of the initial HPCs. The purified HPCs bear the primitive HPC phenotype, i.e., they are consistently CD34+, largely CD33-/45RA-, and in part HLA-DR-/low/CD38-/low/Thy-1+. In optimized semi-solid culture, the purified erythroid/multipotent HPCs give rise to macroscopic colonies (10,000-150,000 cells/clone, > 0.5 mm size colonies). This purification methodology compares favorably with previously reported procedures in terms of combined HPC frequency and recovery: availability of a large number of highly purified, early HPCs will provide an experimental tool for analysis of the molecular/cellular basis of early hematopoiesis. We have investigated by reverse transcription-polymerase chain reaction (RT-PCR) the mRNA expression of homeobox B (HOXB) cluster genes in purified HPCs induced in liquid suspension culture to gradual erythroid or granulopoietic (largely eosinophilic) differentiation and maturation by differential growth factor (GF) stimulus. Only B3 is expressed in quiescent HPCs. After GF treatment B3 expression is enhanced in the initial 24 h and then through erythroid and granulopoietic differentiation and maturation. HOXB4 and B5 are induced at slightly later times and expressed through maturation in both lineages, while B6 is selectively induced in granulocytic differentiation. B2 is transiently expressed at low level in the granulopoietic pathway, while it is detected only in advanced stages of erythropoiesis; B7, B8 and B9 are essentially not detected. Functional studies were performed with antisense phosphorothioate oligomers to HOX mRNAs including: 1) anti-B3 oligomer (alpha-B3) treatment of purified HPCs induces a striking blockade of both erythroid and granulomonocytic colony formation, 2) alpha-B6 selectively and markedly inhibits granulomonocytic colony formation, 3) alpha-B4 and alpha-B5 cause a significant, less pronounced decrease of both colony types and finally, 4) alpha-B2 and alpha-B7, alpha-B9 exert little and no effect respectively. PMID:7488973

  1. Post-splenectomy intrapancreatic accessory spleen mimicking endocrine tumor of the pancreas

    PubMed Central

    Zhu, Hong-xu; Lou, Wen-hui; Kuang, Tian-tao; Wang, Dan-song

    2014-01-01

    INTRODUCTION Intrapancreatic accessory spleen is an uncommon congenital abnormality of the spleen with no indication for surgical intervention. Among the few cases reported, IPAS coexisted with a normal spleen. We here report the first case of IPAS arising a couple years after splenectomy with the appearance of an endocrine tumor of the pancreas. PRESENTATION OF CASE A 62-year-old female presented with a one-week history of left upper quadrant discomfort. She had splenectomy for the treatment of hypersplenism caused by cirrhotic portal hypertension two years before this admission. Her physical examination was unremarkable and laboratory data was within the normal range. Both the ultrasonography and magnetic resonance image revealed a small oval-shaped mass in the tail of her pancreas with the diameter 2 cm or less. A distal pancreatectomy was performed for the suspection of malignant neuroendocrine tumor of the pancreas. An intrapancreatic accessory spleen was confirmed by the pathologic examination. DISCUSSION Intrapancreatic accessory spleen is one kind of congenital ectopic spleen without indication for operative intervention. We present the case to support that intrapancreatic accessory spleen may enlarge through a compensatory mechanism, and raise the awareness of this intrapacreatic entity to avoid unnecessary surgical operation. CONCLUSION IPAS should be highly considered as a differential diagnosis while the lesion is no more than 2.5 cm in diameter and/or other accessory spleens show around the splenic hilum. PMID:25437661

  2. The Relationships Between Motivations of Intergroup Differentiation as a Function of Different Dimensions of Social Identity

    Microsoft Academic Search

    Nagihan Ta?demir

    2011-01-01

    This article aims to classify social identity-based theories of intergroup differentiation in terms of different dimensions of social identity to understand further the motivational bases of intergroup differentiation. For this purpose, I attempt to incorporate three lines of research in social psychology: (a) theories examining intergroup differentiation as a function of social identity, namely social identity theory and SCT; (b)

  3. Numerical Calculation of Bessel Functions by Solving Differential Equations and Its Application

    Microsoft Academic Search

    Mohd ABDUR RASHID; Masao KODAMA

    1999-01-01

    SUMMARY The method solving Bessel's differential equa- tion for calculating numerical values of the Bessel function J? (x) is not usually used, but it is made clear here that the differential equation method can give very precise numerical values of J? (x), and is very effective if we do not mind computing time. Here we improved the differential equation method

  4. Differential connexin function enhances self-renewal in glioblastoma.

    PubMed

    Hitomi, Masahiro; Deleyrolle, Loic P; Mulkearns-Hubert, Erin E; Jarrar, Awad; Li, Meizhang; Sinyuk, Maksim; Otvos, Balint; Brunet, Sylvain; Flavahan, William A; Hubert, Christopher G; Goan, Winston; Hale, James S; Alvarado, Alvaro G; Zhang, Ao; Rohaus, Mark; Oli, Muna; Vedam-Mai, Vinata; Fortin, Jeff M; Futch, Hunter S; Griffith, Benjamin; Wu, Qiulian; Xia, Chun-Hong; Gong, Xiaohua; Ahluwalia, Manmeet S; Rich, Jeremy N; Reynolds, Brent A; Lathia, Justin D

    2015-05-19

    The coordination of complex tumor processes requires cells to rapidly modify their phenotype and is achieved by direct cell-cell communication through gap junction channels composed of connexins. Previous reports have suggested that gap junctions are tumor suppressive based on connexin 43 (Cx43), but this does not take into account differences in connexin-mediated ion selectivity and intercellular communication rate that drive gap junction diversity. We find that glioblastoma cancer stem cells (CSCs) possess functional gap junctions that can be targeted using clinically relevant compounds to reduce self-renewal and tumor growth. Our analysis reveals that CSCs express Cx46, while Cx43 is predominantly expressed in non-CSCs. During differentiation, Cx46 is reduced, while Cx43 is increased, and targeting Cx46 compromises CSC maintenance. The difference between Cx46 and Cx43 is reflected in elevated cell-cell communication and reduced resting membrane potential in CSCs. Our data demonstrate a pro-tumorigenic role for gap junctions that is dependent on connexin expression. PMID:25959821

  5. Differentiation of reprogrammed mouse cardiac fibroblasts into functional cardiomyocytes.

    PubMed

    Jiang, Bo; Dong, Hongyan; Li, Qingpeng; Yu, Yong; Zhang, Zhifeng; Zhang, Yazhou; Wang, Gang; Zhang, Zhongming

    2013-06-01

    Fibroblasts can be reprogrammed by ectopic expression of reprogramming factors to yield induced pluripotent stem (iPS) cells that are capable of transdifferentiating into diverse types of somatic cell lines. In this study, we examined if functional cardiomyocytes (CMs) can be produced from mouse cardiac fibroblasts (CFs), using iPS cell factor-based reprogramming. CFs were isolated from Oct4-GFP-C57 mice and infected with a retrovirus expressing the Yamanaka reprogramming factors, Oct4, Sox2, Klf4, and c-Myc to reprogram the CFs into a CF-iPS cell line. Primary mouse embryonic fibroblast cells (MEFs) were used as a control. We found that the dedifferentiated CF-iPS cells showed similar biological characteristics (morphology, pluripotent factor expression, and methylation level) as embryonic stem cells (ESs) and MEF-iPS cells. We used the classical embryoid bodies (EBs)-based method and a transwell CM co-culture system to simulate the myocardial paracrine microenvironment for performing CF-iPS cell cardiogenic differentiation. Under this simulated myocardial microenvironment, CF-iPS cells formed spontaneously beating EBs. The transdifferentiated self-beating cells expressed cardiac-specific transcription and structural factors and also displayed typical myocardial morphology and electrophysiological characteristics. CFs can be dedifferentiated into iPS cells and further transdifferentiated into CMs. CFs hold great promise for CM regeneration as an autologous cell source for functional CM in situ without the need for exogenous cell transplantation in ischemic heart disease. PMID:23212180

  6. Enumeration and Generating Functions of Differential Rota-Baxter Words

    Microsoft Academic Search

    Li Guo; William Y. Sit

    2010-01-01

    In this paper, the methods and results in enumeration and generation of Rota–Baxter words in Guo and Sit (Algebraic and Algorithmic\\u000a Aspects of Differential and Integral Operators (AADIOS), Math. Comp. Sci., vol. 4, Sp. Issue (2,3), 2011) are generalized and applied to a free, non-commutative, non-unitary, ordinary differential Rota–Baxter algebra with one\\u000a generator. A differential Rota–Baxter algebra is an associative

  7. Cell membrane is a major locus for ultraviolet B-induced alterations in accessory cells.

    PubMed Central

    Krutmann, J; Khan, I U; Wallis, R S; Zhang, F; Rich, E A; Ellner, J J; Elmets, C A

    1990-01-01

    In vitro ultraviolet B (UVB) irradiation of human blood monocytes inhibits their accessory cell function for antigen- and mitogen-induced T cell responses. These studies were designed to characterize the nature of the UVB-induced defect in human monocyte accessory cell function. Irradiated monocytes were deficient in their ability to serve as accessory cells for OKT3-induced T cell activation. In vitro exposure of monocytes to 100 J/m2 UVB completely inhibited the T cell proliferative response (51502 cpm, non-UVB-irradiated; 302 cpm, UVB-irradiated). Analysis of the accessory signals altered by UVB indicated that irradiated monocytes were incapable of binding to OKT3 molecules attached to the CD3 antigen on T cells. Provision of an alternative mechanism for binding of OKT3 molecules by attaching anti-mouse IgG to the bottom of microtiter wells completely restored accessory cell function. Further characterization of the defect demonstrated that UVB radiation did not deplete p72 Fc receptors from the surface of irradiated monocytes. However, UVB exposure did produce a dose-dependent decrease in monocyte membrane expression of ICAM-1. It is proposed that UVB radiation leads to changes within the cell membrane that inhibit the ability of monocytes to express selected molecules necessary for binding of T cells. Images PMID:1970582

  8. The MIMIC Model as a Tool for Differential Bundle Functioning Detection

    ERIC Educational Resources Information Center

    Finch, W. Holmes

    2012-01-01

    Increasingly, researchers interested in identifying potentially biased test items are encouraged to use a confirmatory, rather than exploratory, approach. One such method for confirmatory testing is rooted in differential bundle functioning (DBF), where hypotheses regarding potential differential item functioning (DIF) for sets of items (bundles)…

  9. The Item Parameter Replication Method for Detecting Differential Functioning in the Polytomous DFIT Framework

    ERIC Educational Resources Information Center

    Raju, Nambury S.; Fortmann-Johnson, Kristen A.; Kim, Wonsuk; Morris, Scott B.; Nering, Michael L.; Oshima, T. C.

    2009-01-01

    The recent study of Oshima, Raju, and Nanda proposes the item parameter replication (IPR) method for assessing statistical significance of the noncompensatory differential item functioning (NCDIF) index within the differential functioning of items and tests (DFIT) framework. Previous Monte Carlo simulations have found that the appropriate cutoff…

  10. Newborn society of fetal urology grade 3 hydronephrosis is equivalent to preserved percentage differential function

    Microsoft Academic Search

    Bradley A. Erickson; Max Maizels; Richard M. Shore; Joseph F. Pazona; Jennifer A. Hagerty; Elizabeth B. Yerkes; Antonio H. Chaviano; William E. Kaplan; Earl Y. Cheng

    2007-01-01

    PurposeIn newborn hydronephrosis (HN), the level of differential function (%df) measured by diuretic renography (DR) is used to judge the need for pyeloplasty. As DR testing is complex, we sought to determine if grading the level of HN (Society of Fetal Urology grade, SFU Gr) by a simple ultrasound correlates with percentage differential function (%df) and thereby obviates the need

  11. A Comparison of Function-Based Differential Reinforcement Interventions for Children Engaging in Disruptive Classroom Behavior

    ERIC Educational Resources Information Center

    LeGray, Matthew W.; Dufrene, Brad A.; Sterling-Turner, Heather; Olmi, D. Joe; Bellone, Katherine

    2010-01-01

    This study provides a direct comparison of differential reinforcement of other behavior (DRO) and differential reinforcement of alternative behavior (DRA). Participants included three children in center-based classrooms referred for functional assessments due to disruptive classroom behavior. Functional assessments included interviews and brief…

  12. Detecting Differential Item Functioning Using IRT and Mantel-Haenszel Techniques: Implementing Procedures and Comparing Results.

    ERIC Educational Resources Information Center

    Baghi, Heibatollah; Ferrara, Steven F.

    Two techniques for detecting differential item functioning (DIF) of test items are compared: (1) item response theory (IRT), using the three-parameter model; and (2) Mantel-Haenszel chi square techniques (MHCS). The steps necessary for identifying differentially functioning items are identified for both approaches. Using data from the 1988…

  13. A general adjoint relation for functional differential and Volterra integral equations with application to control

    Microsoft Academic Search

    N. H. McClamroch

    1971-01-01

    A general adjoint relation is developed between solutions of linear functional differential equations and linear Volterra integral equations. Several useful representations for solutions of such equations arise as a consequence of the adjoint relationship. These representations are then used to obtain directly several results for controlling systems described by either linear functional differential equations or linear Volterra integral equations.

  14. 21 CFR 872.6640 - Dental operative unit and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Dental operative unit and accessories. 872...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6640 Dental operative unit and accessories....

  15. 21 CFR 872.3980 - Endosseous dental implant accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Endosseous dental implant accessories. 872.3980...AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3980 Endosseous dental implant accessories. (a)...

  16. 21 CFR 872.4200 - Dental handpiece and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Dental handpiece and accessories. 872.4200...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4200 Dental handpiece and accessories. (a)...

  17. 21 CFR 872.6250 - Dental chair and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Dental chair and accessories. 872.6250...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6250 Dental chair and accessories. (a)...

  18. 21 CFR 872.4200 - Dental handpiece and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Dental handpiece and accessories. 872.4200...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4200 Dental handpiece and accessories. (a)...

  19. 21 CFR 872.4200 - Dental handpiece and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Dental handpiece and accessories. 872.4200...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4200 Dental handpiece and accessories. (a)...

  20. 21 CFR 872.6250 - Dental chair and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Dental chair and accessories. 872.6250...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6250 Dental chair and accessories. (a)...

  1. 21 CFR 872.3980 - Endosseous dental implant accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Endosseous dental implant accessories. 872.3980...AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3980 Endosseous dental implant accessories. (a)...

  2. 21 CFR 872.6640 - Dental operative unit and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Dental operative unit and accessories. 872...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6640 Dental operative unit and accessories....

  3. 21 CFR 872.6640 - Dental operative unit and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Dental operative unit and accessories. 872...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6640 Dental operative unit and accessories....

  4. 21 CFR 872.4200 - Dental handpiece and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Dental handpiece and accessories. 872.4200...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4200 Dental handpiece and accessories. (a)...

  5. 21 CFR 872.3980 - Endosseous dental implant accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 false Endosseous dental implant accessories. 872.3980...AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3980 Endosseous dental implant accessories. (a)...

  6. 21 CFR 872.4200 - Dental handpiece and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Dental handpiece and accessories. 872.4200...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4200 Dental handpiece and accessories. (a)...

  7. 21 CFR 872.3980 - Endosseous dental implant accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 false Endosseous dental implant accessories. 872.3980...AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3980 Endosseous dental implant accessories. (a)...

  8. 21 CFR 872.6640 - Dental operative unit and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Dental operative unit and accessories. 872...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6640 Dental operative unit and accessories....

  9. 21 CFR 872.3980 - Endosseous dental implant accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Endosseous dental implant accessories. 872.3980...AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3980 Endosseous dental implant accessories. (a)...

  10. 21 CFR 872.6250 - Dental chair and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Dental chair and accessories. 872.6250...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6250 Dental chair and accessories. (a)...

  11. 21 CFR 872.6640 - Dental operative unit and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Dental operative unit and accessories. 872...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6640 Dental operative unit and accessories....

  12. 21 CFR 872.6250 - Dental chair and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Dental chair and accessories. 872.6250...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6250 Dental chair and accessories. (a)...

  13. 21 CFR 872.6250 - Dental chair and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Dental chair and accessories. 872.6250...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6250 Dental chair and accessories. (a)...

  14. 19 CFR 10.537 - Accessories, spare parts, or tools.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Singapore Free Trade Agreement Rules of Origin § 10.537 Accessories, spare parts, or tools. Accessories, spare parts, or tools that are...

  15. 19 CFR 10.456 - Accessories, spare parts or tools.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Chile Free Trade Agreement Rules of Origin § 10.456 Accessories, spare parts or tools. Accessories, spare parts or tools that form part of the...

  16. Gene function in early mouse embryonic stem cell differentiation

    Microsoft Academic Search

    Kagnew Hailesellasse Sene; Christopher J Porter; Gareth Palidwor; Carolina Perez-Iratxeta; Enrique M Muro; Pearl A Campbell; Michael A Rudnicki; Miguel A Andrade-Navarro

    2007-01-01

    BACKGROUND: Little is known about the genes that drive embryonic stem cell differentiation. However, such knowledge is necessary if we are to exploit the therapeutic potential of stem cells. To uncover the genetic determinants of mouse embryonic stem cell (mESC) differentiation, we have generated and analyzed 11-point time-series of DNA microarray data for three biologically equivalent but genetically distinct mESC

  17. 19 CFR 10.456 - Accessories, spare parts or tools.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Accessories, spare parts or tools. 10.456 Section 10.456 Customs Duties...Origin § 10.456 Accessories, spare parts or tools. Accessories, spare parts or tools that form part of the good's standard...

  18. 19 CFR 10.456 - Accessories, spare parts or tools.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Accessories, spare parts or tools. 10.456 Section 10.456 Customs Duties...Origin § 10.456 Accessories, spare parts or tools. Accessories, spare parts or tools that form part of the good's standard...

  19. 19 CFR 10.456 - Accessories, spare parts or tools.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 false Accessories, spare parts or tools. 10.456 Section 10.456 Customs Duties...Origin § 10.456 Accessories, spare parts or tools. Accessories, spare parts or tools that form part of the good's standard...

  20. Detection of accessory spleens with indium 111-labeled autologous platelets

    Microsoft Academic Search

    Harmon H. Davis; Ajit Varki; W. A. Heaton; B. A. Siegel

    1980-01-01

    In two patients with recurrent immune thrombocytopenia, accessory splenic tissue was demonstrated by radionuclide imaging following administration of indium 111-labeled autologous platelets. In one of these patients, no accessory splenic tissue was seen on images obtained with technetium 99m sulfur colloid. This new technique provides a simple means for demonstrating accessory spleens and simultaneously evaluating the life-span of autologous platelets.

  1. Multiple ancient schwannoma of the accessory nerve: a case report.

    PubMed

    George, N A; Balagopal, P G; Somanath, T; Sebastian, P

    2012-01-01

    We are reporting a case of multiple ancient schwannoma of the accessory nerve in a 57 year old male. Accessory schwannomas are rare with only 19 cases reported in literature so far. Ancient schwannoma is even rarer in the head and neck region with no other cases associated with the accessory nerve being reported in literature so far. PMID:22227549

  2. Important Information ................................... 2 ~ 3 Supplied Accessories ......................................... 3

    E-print Network

    Kleinfeld, David

    Accessories ......................................... 3 · Before Operating Your Television includes basic operating instructions in Spanish and French. SPANISH is on page 6, 27. FRENCH is on page 7 TELEVISION MODELS 13N-M100 13N-M150 B #12;2 Welcome to the SHARP Family.We are pleased that you are now

  3. Electronic Position Sensor for Power Operated Accessory

    DOEpatents

    Haag, Ronald H.; Chia, Michael I.

    2005-05-31

    An electronic position sensor for use with a power operated vehicle accessory, such as a power liftgate. The position sensor includes an elongated resistive circuit that is mounted such that it is stationary and extends along the path of a track portion of the power operated accessory. The position sensor further includes a contact nub mounted to a link member that moves within the track portion such that the contact nub is slidingly biased against the elongated circuit. As the link member moves under the force of a motor-driven output gear, the contact nub slides along the surface of the resistive circuit, thereby affecting the overall resistance of the circuit. The position sensor uses the overall resistance to provide an electronic position signal to an ECU, wherein the signal is indicative of the absolute position of the power operated accessory. Accordingly, the electronic position sensor is capable of providing an electronic signal that enables the ECU to track the absolute position of the power operated accessory.

  4. Accessories to the crime: Recent advances in HIV accessory protein biology

    Microsoft Academic Search

    Thomas Gramberg; Nicole Sunseri; Nathaniel R. Landau

    2009-01-01

    Recent advances in understanding the roles of the lentiviral accessory proteins have provided fascinating insight into the\\u000a molecular biology of the virus and uncovered previously unappreciated innate immune mechanisms by which the host defends itself.\\u000a HIV-1 and other lentiviruses have developed accessory proteins that counterattack the antiviral defenses in a sort of evolutionary\\u000a battle. The virus is remarkably adept at

  5. Finding all bessel type solutions for linear differential equations with rational function coefficients

    Microsoft Academic Search

    Mark van Hoeij; Quan Yuan

    2010-01-01

    A linear differential equation with rational function coefficients has a Bessel type solution when it is solvable in terms of Bv(f), Bv+1(f). For second order equations, with rational function coefficients, f must be a rational function or the square root of a rational function. An algorithm was given by Debeerst, van Hoeij, and Koepf, that can compute Bessel type solutions

  6. Dynamic Network-Based Relevance Score Reveals Essential Proteins and Functional Modules in Directed Differentiation

    PubMed Central

    Wu, Chia-Chou; Lin, Che

    2015-01-01

    The induction of stem cells toward a desired differentiation direction is required for the advancement of stem cell-based therapies. Despite successful demonstrations of the control of differentiation direction, the effective use of stem cell-based therapies suffers from a lack of systematic knowledge regarding the mechanisms underlying directed differentiation. Using dynamic modeling and the temporal microarray data of three differentiation stages, three dynamic protein-protein interaction networks were constructed. The interaction difference networks derived from the constructed networks systematically delineated the evolution of interaction variations and the underlying mechanisms. A proposed relevance score identified the essential components in the directed differentiation. Inspection of well-known proteins and functional modules in the directed differentiation showed the plausibility of the proposed relevance score, with the higher scores of several proteins and function modules indicating their essential roles in the directed differentiation. During the differentiation process, the proteins and functional modules with higher relevance scores also became more specific to the neuronal identity. Ultimately, the essential components revealed by the relevance scores may play a role in controlling the direction of differentiation. In addition, these components may serve as a starting point for understanding the systematic mechanisms of directed differentiation and for increasing the efficiency of stem cell-based therapies. PMID:25977693

  7. In vitro multipotent differentiation and barrier function of a human mammary epithelium

    Microsoft Academic Search

    Aaron M. Marshall; Vaibhav P. Pai; Maureen A. Sartor; Nelson D. Horseman

    2009-01-01

    As demonstrated by a variety of animal studies, barrier function in the mammary epithelium is essential for a fully functioning\\u000a and differentiated gland. However, there is a paucity of information on barrier function in human mammary epithelium. Here,\\u000a we have established characteristics of a polarizing differentiating model of human mammary epithelial cells capable of forming\\u000a a high-resistance\\/low-conductance barrier in a

  8. Solutions of linear ordinary differential equations in terms of special functions

    Microsoft Academic Search

    Manuel Bronstein; Sébastien Lafaille

    2002-01-01

    We describe a new algorithm for computing special function solutions of the form y(x) = m(x)F(?(x)) of second order linear ordinary differential equations, where m(x) is an arbitrary Liouvillian function, ?(x) is an arbitrary rational function, and F satisfies a given second order linear ordinary differential equation. Our algorithm, which is based on finding an appropriate point transformation between the

  9. Atrioventricular accessory pathway with anterograde decremental conduction property

    PubMed Central

    Fujita, Satoshi; Fujii, Eitaro; Sugiura, Shinya; Ito, Masaaki

    2013-01-01

    We report a case of atrioventricular (AV) accessory pathway with anterograde decremental conduction property. The ? wave polarity suggested the presence of a right posteroseptal accessory AV pathway. During atrial pacing, Wenckebach-type AV block over the accessory pathway was observed with prolongation of the local AV conduction time without the change in QRS morphology. No retrograde ventriculoatrial conduction was observed. During mapping of the right midseptal area, mechanical conduction block at the level of the proximal input to the accessory pathway was induced repeatedly by catheter manipulation. Radiofrequency energy delivery eliminated the accessory pathway. In this case only the bump phenomenon was the best marker of successful ablation. PMID:23780770

  10. ESF GROUND SUPPORT - MATERIAL DEDICATION ANALYSIS FOR STRUCTURAL STEEL AND ACCESSORIES FROM A COMMERCIAL GRADE SOURCE

    SciTech Connect

    M.D. Stine

    1996-01-23

    The purpose of this analysis is to select the critical characteristics to be verified for steel sets and accessories and the verification methods to be implemented through a material dedication process for the procurement and use of commercial grade structural steel sets and accessories (which have a nuclear safety function) to be used in ground support (with the exception of alcove ground support and alcove opening framing, which are not addressed in this analysis) for the Exploratory Studies Facility (ESF) Topopah Spring (TS) Loop. The ESF TS Loop includes the North Ramp, Main Drift, and South Ramp underground openings.

  11. Description of all conformally invariant differential operators, acting on scalar functions

    E-print Network

    Petko Nikolov; Tihomir Valchev

    2006-01-19

    We give an algorithm to write down all conformally invariant differential operators acting between scalar functions on Minkowski space. All operators of order k are nonlinear and are functions on a finite family of functionally independent invariant operators of order up to k. The independent differential operators of second order are three and we give an explicit realization of them. The applied technique is based on the jet bundle formalism, algebraization of the the differential operators, group action and dimensional reduction. As an illustration of this method we consider the simpler case of differential operators between analytic functions invariant under the modular group. We give a power series generating explicitly all the functionally independent invariant operators of an arbitrary order.

  12. Forming functional fat: a growing understanding of adipocyte differentiation

    Microsoft Academic Search

    Ana G. Cristancho; Mitchell A. Lazar

    2011-01-01

    Adipose tissue, which is primarily composed of adipocytes, is crucial for maintaining energy and metabolic homeostasis. Adipogenesis is thought to occur in two stages: commitment of mesenchymal stem cells to a preadipocyte fate and terminal differentiation. Cell shape and extracellular matrix remodelling have recently been found to regulate preadipocyte commitment and competency by modulating WNT and RHO-family GTPase signalling cascades.

  13. Redundancy of myostatin and growth\\/differentiation factor 11 function

    Microsoft Academic Search

    Alexandra C McPherron; Thanh V Huynh; Se-Jin Lee

    2009-01-01

    BACKGROUND: Myostatin (Mstn) and growth\\/differentiation factor 11 (Gdf11) are highly related transforming growth factor ? (TGF?) family members that play important roles in regulating embryonic development and adult tissue homeostasis. Despite their high degree of sequence identity, targeted mutations in these genes result in non-overlapping phenotypes affecting distinct biological processes. Loss of Mstn in mice causes a doubling of skeletal

  14. MTH5105 Differential and Integral Analysis 2009-2010 1. Differentiable functions: Definition of differentiability. Algebra of derivatives, chain rule. Derivative of inverse

    E-print Network

    Prellberg, Thomas

    . state and use key theorems concerning differentiable functions, such as Rolle's Theorem, the Mean Value's Theorem, Mean Value Theorem and applications. Taylor's Theorem. 2. Integration: Darboux definition). Fundamental Theorem of the calculus, integral form of the Mean Value Theorem and of the remainder in Taylor

  15. MTH5105 Differential and Integral Analysis 2008-2009 1. Differentiable functions: Definition of differentiability. Algebra of derivatives, chain rule. Derivative of inverse

    E-print Network

    Prellberg, Thomas

    . state and use key theorems concerning differentiable functions, such as Rolle's Theorem, the Mean Value's Theorem, Mean Value Theorem and applications. Taylor's Theorem. 2. Integration: Darboux definition). Fundamental Theorem of the calculus, integral form of the Mean Value Theorem and of the remainder in Taylor

  16. MTH5105 Differential and Integral Analysis 2010-2011 1. Differentiable functions: Definition of differentiability. Algebra of derivatives, chain rule. Derivative of inverse

    E-print Network

    Prellberg, Thomas

    . state and use key theorems concerning differentiable functions, such as Rolle's Theorem, the Mean Value's Theorem, Mean Value Theorem and applications. Taylor's Theorem. 2. Integration: Darboux definition). Fundamental Theorem of the calculus, integral form of the Mean Value Theorem and of the remainder in Taylor

  17. Mycophenolic Acid Differentially Impacts B Cell Function Depending on the Stage of Differentiation

    PubMed Central

    Karnell, Jodi L.; Karnell, Fredrick G.; Stephens, Geoffrey L.; Rajan, Bhargavi; Morehouse, Chris; Li, Ying; Swerdlow, Bonnie; Wilson, Mildred; Goldbach-Mansky, Raphaela; Groves, Christopher; Coyle, Anthony J.; Herbst, Ronald; Ettinger, Rachel

    2014-01-01

    Production of pathogenic Abs contributes to disease progression in many autoimmune disorders. The immunosuppressant agent mycophenolic acid (MPA) has shown clinical efficacy for patients with autoimmunity. The goal of these studies was to elucidate the mechanisms of action of MPA on B cells isolated from healthy individuals and autoimmune patients. In this study, we show that MPA significantly inhibited both proliferation and differentiation of primary human B cells stimulated under various conditions. Importantly, MPA did not globally suppress B cell responsiveness or simply induce cell death, but rather selectively inhibited early activation events and arrested cells in the G0/G1 phase of the cell cycle. Furthermore, MPA blocked expansion of both naive and memory B cells and prevented plasma cell (PC) differentiation and Ab production from healthy controls and individuals with rheumatoid arthritis. Finally, whereas MPA potently suppressed Ig secretion from activated primary B cells, terminally differentiated PCs were not susceptible to inhibition by MPA. The target of MPA, IMPDH2, was found to be downregulated in PCs, likely explaining the resistance of these cells to MPA. These results suggest that MPA provides benefit in settings of autoimmunity by directly preventing activation and PC differentiation of B cells; however, MPA is unlikely to impact autoantibody production by preexisting, long-lived PCs. PMID:21873529

  18. Functional gene screening in embryonic stem cells implicates Wnt antagonism in neural differentiation

    Microsoft Academic Search

    Jerôme Aubert; Hannah Dunstan; Ian Chambers; Austin Smith

    2002-01-01

    The multilineage differentiation capacity of mouse embryonic stem (ES) cells offers a potential testing platform for gene products that mediate mammalian lineage determination and cellular specialization. Identification of such differentiation regulators is crucial to harnessing ES cells for pharmaceutical discovery and cell therapy. Here we describe the use of episomal expression technology for functional evaluation of cDNA clones during ES-cell

  19. Some Properties of Solutions of a Functional-Differential Equation of Second Order with Delay

    PubMed Central

    Ana Ilea, Veronica

    2014-01-01

    Existence, uniqueness, data dependence (monotony, continuity, and differentiability with respect to parameter), and Ulam-Hyers stability results for the solutions of a system of functional-differential equations with delays are proved. The techniques used are Perov's fixed point theorem and weakly Picard operator theory. PMID:24683363

  20. Some properties of solutions of a functional-differential equation of second order with delay.

    PubMed

    Ilea, Veronica Ana; Otrocol, Diana

    2014-01-01

    Existence, uniqueness, data dependence (monotony, continuity, and differentiability with respect to parameter), and Ulam-Hyers stability results for the solutions of a system of functional-differential equations with delays are proved. The techniques used are Perov's fixed point theorem and weakly Picard operator theory. PMID:24683363

  1. Achievement Motivation as a Function of Assimilation and Differentiation Needs

    Microsoft Academic Search

    DeLeon L. Gray; Kimberly Rios

    2012-01-01

    Building upon Optimal Distinctiveness Theory (Brewer, 1991), we propose that students will exhibit increased self-regulatory persistence and performance to satisfy their needs for assimilation and differentiation. In Study 1, undergraduates rated the importance of 16 achievement-related tasks (e.g., studying for examinations, class participation). A within-persons hierarchical linear model revealed that the more students perceived enacting these behaviors as satisfying their

  2. Stability in functional differential equations established using fixed point theory

    Microsoft Academic Search

    Chuhua Jin; Jiaowan Luo

    2008-01-01

    In this paper we consider a nonlinear scalar delay differential equation with variable delays and give some new conditions for the boundedness and stability by means of Krasnoselskii’s fixed point theory. A stability theorem with a necessary and sufficient condition is proved. The results in [T.A. Burton, Stability by fixed point theory or Liapunov’s theory: A comparison, Fixed Point Theory

  3. Differential improvement of cognitive functions in recovering alcoholic women

    Microsoft Academic Search

    Marjorie S. Fabian; Oscar A. Parsons

    1983-01-01

    In Study 1, 40 long-term sober alcoholics (mean age 42.15 yrs) performed at or near the level of 40 age-matched short-term sober alcoholics on several perceptuomotor speed tasks, at the level of 70 age-matched nonalcoholic controls on several complex problem-solving measures, and intermediate to the 2 groups on most measures, suggesting a differential improvement in cognitive abilities. In Study 2,

  4. [Accessory renal arteries in human fetuses].

    PubMed

    Go?cicka, D; Szpinda, M; Kochan, J

    1996-12-01

    Using conventional anatomical methods, renal arteries of 140 human fetuses were studied. It was found (21.1%) that the accessory renal arteries occurred in a three-fold manner: 1. as single arteries (19.2%), 2. as double arteries (2.1%) and 3. as triplex arteries (0.7%). More often they originated from the right part of the circumference of the abdominal aorta, mainly in the female fetuses. These arteries penetrated the following segments of the kidney: the inferior (12.9%), the superior (2.3%), the anterior inferior (2.8%), the posterior (2.1%) and the anterior superior (1.5%). They crossed the renal pelvis more often in front (12.2%) than from behind of it (5%). The frequency of the occurrence of the accessory arteries depends not from the age of the fetus. PMID:9082875

  5. Differentiation of human neural progenitor cells in functionalized hydrogel matrices.

    PubMed

    Liedmann, Andrea; Frech, Stefanie; Morgan, Peter J; Rolfs, Arndt; Frech, Moritz J

    2012-01-01

    Hydrogel-based three-dimensional (3D) scaffolds are widely used in the field of regenerative medicine, translational medicine, and tissue engineering. Recently, we reported the effect of scaffold formation on the differentiation and survival of human neural progenitor cells (hNPCs) using PuraMatrix™ (RADA-16) scaffolds. Here, we were interested in the impact of PuraMatrix modified by the addition of short peptide sequences, based on a bone marrow homing factor and laminin. The culture and differentiation of the hNPCs in the modified matrices resulted in an approximately fivefold increase in neuronal cells. The examination of apoptotic and necrotic cells, as well as the level of the anti-apoptotic protein Bcl-2, indicates benefits for cells hosted in the modified formulations. In addition, we found a trend to lower proportions of apoptotic or necrotic neuronal cells in the modified matrices. Interestingly, the neural progenitor cell pool was increased in all the tested matrices in comparison to the standard 2D culture system, while no difference was found between the modified matrices. We conclude that a combination of elevated neuronal differentiation and a protective effect of the modified matrices underlies the increased proportion of neuronal cells. PMID:23515105

  6. Differentiation of Human Neural Progenitor Cells in Functionalized Hydrogel Matrices

    PubMed Central

    Liedmann, Andrea; Frech, Stefanie; Morgan, Peter J.; Rolfs, Arndt

    2012-01-01

    Abstract Hydrogel-based three-dimensional (3D) scaffolds are widely used in the field of regenerative medicine, translational medicine, and tissue engineering. Recently, we reported the effect of scaffold formation on the differentiation and survival of human neural progenitor cells (hNPCs) using PuraMatrix™ (RADA-16) scaffolds. Here, we were interested in the impact of PuraMatrix modified by the addition of short peptide sequences, based on a bone marrow homing factor and laminin. The culture and differentiation of the hNPCs in the modified matrices resulted in an approximately fivefold increase in neuronal cells. The examination of apoptotic and necrotic cells, as well as the level of the anti-apoptotic protein Bcl-2, indicates benefits for cells hosted in the modified formulations. In addition, we found a trend to lower proportions of apoptotic or necrotic neuronal cells in the modified matrices. Interestingly, the neural progenitor cell pool was increased in all the tested matrices in comparison to the standard 2D culture system, while no difference was found between the modified matrices. We conclude that a combination of elevated neuronal differentiation and a protective effect of the modified matrices underlies the increased proportion of neuronal cells. PMID:23515105

  7. Regulation of ES cell differentiation by functional and conformational modulation of p53.

    PubMed Central

    Sabapathy, K; Klemm, M; Jaenisch, R; Wagner, E F

    1997-01-01

    Embryonic stem (ES) cell lines were used to examine the role of p53 during in vitro differentiation. Undifferentiated ES cells express high levels of p53 exclusively in the wild-type conformation, immunoprecipitable by monoclonal antibody PAb246, and p53 was found to be functionally active as determined by its ability to bind DNA specifically and to activate transcription of target genes. Differentiation in vitro resulted in a decrease in the levels of p53 and in a shift in its conformational status to the mutant form, detectable by monoclonal antibody PAb240, with a concomitant loss of functional activity. The presence of functional p53 in the undifferentiated ES cells renders them hypersensitive to UV irradiation, whereas the differentiated cells were resistant to UV treatment. ES cells lacking p53 exhibit enhanced proliferation in both the undifferentiated and differentiated state, and apoptosis accompanying differentiation was found to be reduced. Furthermore, wild-type ES cells undergoing apoptosis expressed functional p53. Expression of the temperature-sensitive p53val135 mutant in wild-type ES cells resulted in a reduction of apoptosis accompanying differentiation when it adopted a mutant conformation at 39 degrees C. These data demonstrate that functional inactivation of p53 allows differentiating cells to escape from apoptosis, and suggest that the conformational switch could regulate the inactivation process. PMID:9321401

  8. A Comparison of Mantel-Haenszel Differential Item Functioning Parameters. LSAC Research Report Series.

    ERIC Educational Resources Information Center

    Schnipke, Deborah L.; Roussos, Louis A.; Pashley, Peter J.

    Differential item functioning (DIF) analyses are conducted to investigate how items function in various subgroups. The Mantel-Haenszel (MH) DIF statistic is used at the Law School Admission Council and other testing companies. When item functioning can be well-described in terms of a one- or two-parameter logistic item response theory (IRT) model…

  9. Towards functional phosphoproteomics by mapping differential phosphorylation events in signaling networks

    E-print Network

    Hirt, Heribert

    REVIEW Towards functional phosphoproteomics by mapping differential phosphorylation events screening for potential cancer therapies and in-depth analysis of phosphoproteomes. In this review, we aim to describe current progress in quantitative phosphoproteomics. This emerging field has changed numerous

  10. Functional gene screening in embryonic stem cell implicates Wnt antagonism in neural differentiation

    E-print Network

    Aubert, Jerome; Dunstan, Hannah; Chambers, Ian; Smith, Austin G

    2002-01-01

    regulators is crucial to harnessing ES cells for pharmaceutical discovery and cell therapy. Here we describe the use of episomal expression technology for functional evaluation of cDNA clones during ES-cell differentiation in vitro. Several candidate c...

  11. Development and Demonstration of Multidimensional IRT-Based Internal Measures of Differential Functioning of Items and Tests.

    ERIC Educational Resources Information Center

    Oshima, T. C.; Raju, Nambury S. Rajo; Flowers, Claudia P.

    1997-01-01

    Defines and demonstrates a framework for studying differential item functioning and differential test functioning for tests that are intended to be multidimensional. The procedure, which is illustrated with simulated data, is an extension of the unidimensional differential functioning of items and tests approach (N. Raju, W. van der Linden, and P.…

  12. Differential reactivity as a function of locus of control in active or passive coping situations

    E-print Network

    Bond, Terri Allison

    1981-01-01

    DIFFERENTIAL REACTIVITY AS A FUNCTION OF LOCUS OF CONTROL IN ACTIVE OR PASSIVE COPING SITUATIONS A Thesis by TERRI ALLISON BOND Submitted to the Graduate College of Texas ARM University i n partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE December 1981 Major Subject: Psychology DIFFERENTIAL REACTIVITY AS A FUNCTION OF LOCUS OF CONTROL IN ACTIVE OR PASSIVE COPING SITUATIONS A Thesis by TERRI ALLISON BOND Approved as to style and content by: hairman o...

  13. Bending analysis of thin functionally graded plates using generalized differential quadrature method

    Microsoft Academic Search

    A. Fereidoon; M. Asghardokht seyedmahalle; A. Mohyeddin

    2011-01-01

    In this paper, the differential quadrature (DQ) method is presented for easy and effective analysis of isotropic functionally\\u000a graded (FG) and functionally graded coated (FGC) thin plates with constant Poisson’s ratio and varying Young’s modulus in\\u000a the thickness direction. The bending of FG and FGC plates under transverse loading has been studied using the polynomial differential\\u000a quadrature (PDQ) and the

  14. On the Relationship between Differential Item Functioning and Item Difficulty: An Issue of Methods? Item Response Theory Approach to Differential Item Functioning

    ERIC Educational Resources Information Center

    Santelices, Maria Veronica; Wilson, Mark

    2012-01-01

    The relationship between differential item functioning (DIF) and item difficulty on the SAT is such that more difficult items tended to exhibit DIF in favor of the focal group (usually minority groups). These results were reported by Kulick and Hu, and Freedle and have been enthusiastically discussed by more recent literature. Examining the…

  15. Behavior near constant solutions of functional differential equations

    NASA Technical Reports Server (NTRS)

    Hale, J. K.

    1974-01-01

    Techniques have been developed to determine in a systematic way the local behavior near constant solutions. Local integral manifolds play a very important role in this development, as they have also for ordinary differential equations. An attempt is made to indicate a few more applications of these methods to some problems in bifurcation in the spirit of Sotomayor (to appear) and to a growth model of Cooke and Yorke (to appear). It is also shown how to prove a theorem on stability under constantly acting disturbances using these methods.

  16. Probabilistic Higher Order Differential Attack and Higher Order Bent Functions

    Microsoft Academic Search

    Tetsu Iwata; Kaoru Kurosawa

    1999-01-01

    . We first show that a Feistel type block cipher is broken ifthe round function is approximated by a low degree vectorial Booleanfunction. The proposed attack is a generalization of the higher orderdifferential attack to a probabilistic one. We next introduce a notion ofhigher order bent functions in order to prevent our attack. We then showtheir explicit constructions.1

  17. Baker-Akhiezer Spinor Kernel and Tau-functions on Moduli Spaces of Meromorphic Differentials

    NASA Astrophysics Data System (ADS)

    Kalla, C.; Korotkin, D.

    2014-08-01

    In this paper we study the Baker-Akhiezer spinor kernel on moduli spaces of meromorphic differentials on Riemann surfaces. We introduce the Baker-Akhiezer tau-function which is related to both the Bergman tau-function (which was studied before in the context of Hurwitz spaces and spaces of holomorphic Abelian and quadratic differentials) and the KP tau-function on such spaces. In particular, we derive variational formulas of Rauch-Ahlfors type on moduli spaces of meromorphic differentials with prescribed singularities: we use the system of homological coordinates, consisting of absolute and relative periods of the meromorphic differential, and show how to vary the fundamental objects associated to a Riemann surface (the matrix of b-periods, normalized Abelian differentials, the Bergman bidifferential, the Szegö kernel and the Baker-Akhiezer spinor kernel) with respect to these coordinates. The variational formulas encode dependence both on the moduli of the Riemann surface and on the choice of meromorphic differential (variation of the meromorphic differential while keeping the Riemann surface fixed corresponds to flows of KP type). Analyzing the global properties of the Bergman and Baker-Akhiezer tau-functions, we establish relationships between various divisor classes on the moduli spaces.

  18. Baker-Akhiezer Spinor Kernel and Tau-functions on Moduli Spaces of Meromorphic Differentials

    NASA Astrophysics Data System (ADS)

    Kalla, C.; Korotkin, D.

    2014-11-01

    In this paper we study the Baker-Akhiezer spinor kernel on moduli spaces of meromorphic differentials on Riemann surfaces. We introduce the Baker-Akhiezer tau-function which is related to both the Bergman tau-function (which was studied before in the context of Hurwitz spaces and spaces of holomorphic Abelian and quadratic differentials) and the KP tau-function on such spaces. In particular, we derive variational formulas of Rauch-Ahlfors type on moduli spaces of meromorphic differentials with prescribed singularities: we use the system of homological coordinates, consisting of absolute and relative periods of the meromorphic differential, and show how to vary the fundamental objects associated to a Riemann surface (the matrix of b-periods, normalized Abelian differentials, the Bergman bidifferential, the Szegö kernel and the Baker-Akhiezer spinor kernel) with respect to these coordinates. The variational formulas encode dependence both on the moduli of the Riemann surface and on the choice of meromorphic differential (variation of the meromorphic differential while keeping the Riemann surface fixed corresponds to flows of KP type). Analyzing the global properties of the Bergman and Baker-Akhiezer tau-functions, we establish relationships between various divisor classes on the moduli spaces.

  19. Dual functions of TAF7L in adipocyte differentiation

    PubMed Central

    Zhou, Haiying; Kaplan, Tommy; Li, Yan; Grubisic, Ivan; Zhang, Zhengjian; Wang, P Jeremy; Eisen, Michael B; Tjian, Robert

    2013-01-01

    The diverse transcriptional mechanisms governing cellular differentiation and development of mammalian tissue remains poorly understood. Here we report that TAF7L, a paralogue of TFIID subunit TAF7, is enriched in adipocytes and white fat tissue (WAT) in mouse. Depletion of TAF7L reduced adipocyte-specific gene expression, compromised adipocyte differentiation, and WAT development as well. Ectopic expression of TAF7L in myoblasts reprograms these muscle precursors into adipocytes upon induction. Genome-wide mRNA-seq expression profiling and ChIP-seq binding studies confirmed that TAF7L is required for activating adipocyte-specific genes via a dual mechanism wherein it interacts with PPAR? at enhancers and TBP/Pol II at core promoters. In vitro binding studies confirmed that TAF7L forms complexes with both TBP and PPAR?. These findings suggest that TAF7L plays an integral role in adipocyte gene expression by targeting enhancers as a cofactor for PPAR? and promoters as a component of the core transcriptional machinery. DOI: http://dx.doi.org/10.7554/eLife.00170.001 PMID:23326641

  20. Chondrocytic Atf4 regulates osteoblast differentiation and function via Ihh.

    PubMed

    Wang, Weiguang; Lian, Na; Ma, Yun; Li, Lingzhen; Gallant, Richard C; Elefteriou, Florent; Yang, Xiangli

    2012-02-01

    Atf4 is a leucine zipper-containing transcription factor that activates osteocalcin (Ocn) in osteoblasts and indian hedgehog (Ihh) in chondrocytes. The relative contribution of Atf4 in chondrocytes and osteoblasts to the regulation of skeletal development and bone formation is poorly understood. Investigations of the Atf4(-/-);Col2a1-Atf4 mouse model, in which Atf4 is selectively overexpressed in chondrocytes in an Atf4-null background, demonstrate that chondrocyte-derived Atf4 regulates osteogenesis during development and bone remodeling postnatally. Atf4 overexpression in chondrocytes of the Atf4(-/-);Col2a1-Atf4 double mutants corrects the reduction in stature and limb in Atf4(-/-) embryos and rectifies the decrease in Ihh expression, Hh signaling, proliferation and accelerated hypertrophy that characterize the Atf4(-/-) developing growth plate cartilages. Unexpectedly, this genetic manipulation also restores the expression of osteoblastic marker genes, namely Ocn and bone sialoprotein, in Atf4(-/-) developing bones. In Atf4(-/-);Col2a1-Atf4 adult mice, all the defective bone parameters found in Atf4(-/-) mice, including bone volume, trabecular number and thickness, and bone formation rate, are rescued. In addition, the conditioned media of ex vivo cultures from wild-type or Atf4(-/-);Col2a1-Atf4, but not Atf4(-/-) cartilage, corrects the differentiation defects of Atf4(-/-) bone marrow stromal cells and Ihh-blocking antibody eliminates this effect. Together, these data indicate that Atf4 in chondrocytes is required for normal Ihh expression and for its paracrine effect on osteoblast differentiation. Therefore, the cell-autonomous role of Atf4 in chondrocytes dominates the role of Atf4 in osteoblasts during development for the control of early osteogenesis and skeletal growth. PMID:22190639

  1. Regeneration niche differentiates functional strategies of desert woody plant species

    PubMed Central

    Briggs, John M.

    2010-01-01

    Plant communities vary dramatically in the number and relative abundance of species that exhibit facilitative interactions, which contributes substantially to variation in community structure and dynamics. Predicting species’ responses to neighbors based on readily measurable functional traits would provide important insight into the factors that structure plant communities. We measured a suite of functional traits on seedlings of 20 species and mature plants of 54 species of shrubs from three arid biogeographic regions. We hypothesized that species with different regeneration niches—those that require nurse plants for establishment (beneficiaries) versus those that do not (colonizers)—are functionally different. Indeed, seedlings of beneficiary species had lower relative growth rates, larger seeds and final biomass, allocated biomass toward roots and height at a cost to leaf mass fraction, and constructed costly, dense leaf and root tissues relative to colonizers. Likewise at maturity, beneficiaries had larger overall size and denser leaves coupled with greater water use efficiency than colonizers. In contrast to current hypotheses that suggest beneficiaries are less “stress-tolerant” than colonizers, beneficiaries exhibited conservative functional strategies suited to persistently dry, low light conditions beneath canopies, whereas colonizers exhibited opportunistic strategies that may be advantageous in fluctuating, open microenvironments. In addition, the signature of the regeneration niche at maturity indicates that facilitation expands the range of functional diversity within plant communities at all ontogenetic stages. This study demonstrates the utility of specific functional traits for predicting species’ regeneration niches in hot deserts, and provides a framework for studying facilitation in other severe environments. Electronic supplementary material The online version of this article (doi:10.1007/s00442-010-1741-y) contains supplementary material, which is available to authorized users. PMID:20686787

  2. 21 CFR 890.3025 - Prosthetic and orthotic accessory.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3025 Prosthetic and orthotic accessory. (a)...

  3. 21 CFR 876.1500 - Endoscope and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Diagnostic Devices § 876.1500 Endoscope and accessories. (a) Identification. An...

  4. 21 CFR 876.5980 - Gastrointestinal tube and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5980 Gastrointestinal tube and accessories. (a)...

  5. 21 CFR 876.5090 - Suprapubic urological catheter and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5090 Suprapubic urological catheter and accessories. (a)...

  6. 21 CFR 876.4300 - Endoscopic electrosurgical unit and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4300 Endoscopic electrosurgical unit and accessories. (a)...

  7. 21 CFR 876.5630 - Peritoneal dialysis system and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5630 Peritoneal dialysis system and accessories. (a)...

  8. 21 CFR 876.1500 - Endoscope and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Diagnostic Devices § 876.1500 Endoscope and accessories. (a) Identification. An...

  9. 21 CFR 876.5090 - Suprapubic urological catheter and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5090 Suprapubic urological catheter and accessories. (a)...

  10. 21 CFR 876.5130 - Urological catheter and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5130 Urological catheter and accessories. (a) Identification....

  11. 21 CFR 876.5090 - Suprapubic urological catheter and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5090 Suprapubic urological catheter and accessories. (a)...

  12. 21 CFR 876.5630 - Peritoneal dialysis system and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5630 Peritoneal dialysis system and accessories. (a)...

  13. 21 CFR 876.5820 - Hemodialysis system and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5820 Hemodialysis system and accessories. (a) Identification....

  14. 21 CFR 876.1500 - Endoscope and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Diagnostic Devices § 876.1500 Endoscope and accessories. (a) Identification. An...

  15. 21 CFR 876.5090 - Suprapubic urological catheter and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5090 Suprapubic urological catheter and accessories. (a)...

  16. 21 CFR 876.5980 - Gastrointestinal tube and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5980 Gastrointestinal tube and accessories. (a)...

  17. 21 CFR 876.5630 - Peritoneal dialysis system and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5630 Peritoneal dialysis system and accessories. (a)...

  18. 21 CFR 876.5820 - Hemodialysis system and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5820 Hemodialysis system and accessories. (a) Identification....

  19. 21 CFR 876.4300 - Endoscopic electrosurgical unit and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4300 Endoscopic electrosurgical unit and accessories. (a)...

  20. 21 CFR 876.1500 - Endoscope and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Diagnostic Devices § 876.1500 Endoscope and accessories. (a) Identification. An...

  1. 21 CFR 876.1500 - Endoscope and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Diagnostic Devices § 876.1500 Endoscope and accessories. (a) Identification. An...

  2. 21 CFR 876.4300 - Endoscopic electrosurgical unit and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4300 Endoscopic electrosurgical unit and accessories. (a)...

  3. 21 CFR 876.5630 - Peritoneal dialysis system and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5630 Peritoneal dialysis system and accessories. (a)...

  4. 21 CFR 876.5820 - Hemodialysis system and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5820 Hemodialysis system and accessories. (a) Identification....

  5. 21 CFR 876.5130 - Urological catheter and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5130 Urological catheter and accessories. (a) Identification....

  6. 21 CFR 876.5130 - Urological catheter and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5130 Urological catheter and accessories. (a) Identification....

  7. 21 CFR 876.5820 - Hemodialysis system and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5820 Hemodialysis system and accessories. (a) Identification....

  8. 21 CFR 876.5090 - Suprapubic urological catheter and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5090 Suprapubic urological catheter and accessories. (a)...

  9. 21 CFR 876.5980 - Gastrointestinal tube and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5980 Gastrointestinal tube and accessories. (a)...

  10. 21 CFR 876.5980 - Gastrointestinal tube and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5980 Gastrointestinal tube and accessories. (a)...

  11. 21 CFR 876.5980 - Gastrointestinal tube and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5980 Gastrointestinal tube and accessories. (a)...

  12. 21 CFR 876.5630 - Peritoneal dialysis system and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5630 Peritoneal dialysis system and accessories. (a)...

  13. 21 CFR 876.5130 - Urological catheter and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5130 Urological catheter and accessories. (a) Identification....

  14. 21 CFR 876.5130 - Urological catheter and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5130 Urological catheter and accessories. (a) Identification....

  15. 21 CFR 876.4300 - Endoscopic electrosurgical unit and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4300 Endoscopic electrosurgical unit and accessories. (a)...

  16. 21 CFR 876.4300 - Endoscopic electrosurgical unit and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4300 Endoscopic electrosurgical unit and accessories. (a)...

  17. 21 CFR 876.5820 - Hemodialysis system and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5820 Hemodialysis system and accessories. (a) Identification....

  18. 21 CFR 890.3025 - Prosthetic and orthotic accessory.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3025 Prosthetic and orthotic accessory. (a)...

  19. 21 CFR 890.3025 - Prosthetic and orthotic accessory.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3025 Prosthetic and orthotic accessory. (a)...

  20. 21 CFR 890.3025 - Prosthetic and orthotic accessory.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3025 Prosthetic and orthotic accessory. (a)...

  1. Non-Azygos Accessory Fissure in Right Upper Lobe Associated with Superior and Inferior Accessory Fissures in Right Lower Lobe

    PubMed Central

    Muttikkal, Thomas Jose Eluvathingal; Deng, Chunli

    2012-01-01

    Accessory fissures in the lungs are common congenital variations, usually detected as incidental findings in radiographs or CT scan. Accessory fissures can act as an anatomic barrier to the spread of inflammatory or neoplastic disease, as well as due to the variant anatomy, mimic lesions. It is important to recognize the presence of accessory fissures, as they affect surgical planning of pulmonary lobectomy and segmentectomy. Accessory fissure in the right upper lobe other than due to the anomalous course of azygos vein is very rare. We report a case of non-azygos accessory fissure, between the apical and the anterior segments of right upper lobe, along with superior and inferior accessory fissures in the right lower lobe. PMID:23393635

  2. Integral estimates for differentiable functions on irregular domains

    SciTech Connect

    Besov, Oleg V [Steklov Mathematical Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2011-02-11

    Integral representations for functions and their partial derivatives in terms of some fixed system of partial derivatives are constructed on irregular domains in a Euclidean space. Embedding theorems for Sobolev-type spaces into a Lebesgue space are established and the norms of the derivatives are estimated. Bibliography: 17 titles.

  3. Functional differential immune responses of Mytilus galloprovincialis to bacterial challenge

    Microsoft Academic Search

    Caterina Ciacci; Barbara Citterio; Michele Betti; Barbara Canonico; Philippe Roch; Laura Canesi

    2009-01-01

    Bivalves are filter-feeders that can accumulate large numbers of bacteria, in particular Vibrio species; these can persist within bivalve tissues largely depending on their sensitivity to the hemolymph bactericidal activity. In this work, functional parameters of the hemolymph of Mytilus galloprovincialis were evaluated in response to in vivo challenge with different bacteria (Gram(?) Vibrio anguillarum and V. splendidus, Gram(+) Micrococcus

  4. Differentiating High-Functioning Autism and Social Phobia

    ERIC Educational Resources Information Center

    Tyson, Katherine E.; Cruess, Dean G.

    2012-01-01

    Both high-functioning autism (HFA) and social phobia (SP) involve profound social interaction deficits. Although these disorders share some similar symptoms, they are conceptualized as distinct. Because both HFA and SP are defined behaviorally, the degree of overlap between the two disorders may result in misinterpretation of symptoms. However,…

  5. Generalization of spherical Bessel's differential equation to functions of order zero

    Microsoft Academic Search

    Isaac I. H. Chen; T. W. Barrett

    1982-01-01

    The generalization of Bessel's equation to functions of order zero was investigated by Sharpe and applied in the theory of the reflection of sound by a paraboloid. Here, a modification of Sharpe's differential equation to express both the spherical Bessel's equation and Bessel's (cylindrical) equation for functions of order zero is introduced. The generalization of the modified spherical Bessel's. equation

  6. Differential equation for SU(3) extension of Bessel function with two indices

    Microsoft Academic Search

    N. Tanimura; O. Tanimura

    1991-01-01

    For the coefficient function of the character expansion of the single-link action in the SU(3) lattice gauge theory, the linear differential equation of the sixth order, which is specified by two integer indices ? and ? of the SU(3) (?,?) representation of the Young tableau, is derived. The asymptotic behavior of the function is derived from the recursion relations. It

  7. On the derivation of asymptotic expansions for special functions from the corresponding differential equations

    Microsoft Academic Search

    L. M. B. C. Campos

    2001-01-01

    Asymptotic expansions of special functions are usually obtained from integral representations e.g. by Watson's lemma. In the present paper a method of derivation of asymptotic expansions is presented, which does not use integral representations, and relies on solutions of the differential equation satisfied by the special functions in question. The method is illustrated by the determination of the asymptotic expansions

  8. An Investigation of Differential Item Functioning in the MELAB Listening Test

    ERIC Educational Resources Information Center

    Aryadoust, Vahid; Goh, Christine C. M.; Kim, Lee Ong

    2011-01-01

    Differential item functioning (DIF) analysis is a way of determining whether test items function differently across subgroups of test takers after controlling for ability level. DIF results are used to evaluate tests' validity arguments. This study uses Rasch measurement to examine the Michigan English Language Assessment Battery listening test…

  9. Children with High-Functioning Autism and Asperger's Syndrome: Can We Differentiate Their Cognitive Profiles?

    ERIC Educational Resources Information Center

    Planche, Pascale; Lemonnier, Eric

    2012-01-01

    The aim of this study was to investigate whether children with high-functioning autism (HFA) and Asperger's syndrome (AS) can be differentiated from each other and from typically developing children on their cognitive profiles. The present study included a total of 45 participants: children with autism (high-functioning autism or Asperger's…

  10. Parental Divorce and Family Functioning: Effects on Differentiation Levels of Young Adults.

    ERIC Educational Resources Information Center

    Johnson, Patrick; Throngren, Jill M.; Smith, Adina J.

    2001-01-01

    Study examines the effect of parental divorce and various dimensions of functioning in the family of origin on young adult development. Results indicate that parental divorce and family functioning significantly affect differentiation levels of young adults. Implications of the results for counselors and future researchers are provided. (Contains…

  11. Connection Rules versus Differential Equations for Envelope Functions in Abrupt Heterostructures

    Microsoft Academic Search

    Bradley A. Foreman

    1998-01-01

    The controversial question of whether envelope functions are continuous or discontinuous at an abrupt heterojunction is addressed by developing a systematic procedure for obtaining interface connection rules from differential equations. The results show that even though modern envelope-function theories are smooth and continuous, their associated connection rules are discontinuous, in agreement with traditional concepts. This resolves the dispute in favor

  12. Solution of a system of linear delay differential equations using the matrix Lambert function

    Microsoft Academic Search

    Sun Yi; A. G. Ulsoy

    2006-01-01

    An approach for the analytical solution to systems of delay differential equations (DDEs) has been developed using the matrix Lambert function. To generalize the Lambert function method for scalar DDEs, we introduce a new matrix, Q when the coefficient matrices in a system of DDEs do not commute. The solution has the form of an infinite series of modes written

  13. Finding all Bessel type solutions for Linear Differential Equations with Rational Function Coefficients

    E-print Network

    Hoeij, Mark van

    Finding all Bessel type solutions for Linear Differential Equations with Rational Function a Bessel type solution when it is solvable in terms of B (f), B+1(f). For second order equations function. An algorithm was given by Debeerst, van Hoeij, and Koepf, that can compute Bessel type solutions

  14. Pedantic Speaking Style Differentiates Asperger Syndrome from High-Functioning Autism.

    ERIC Educational Resources Information Center

    Ghaziuddin, Mohammad; Gerstein, Leonore

    1996-01-01

    Seventeen patients with Asperger syndrome (AS) and a mean IQ of 97 were compared with a control group of 13 patients with normal intelligence or high-functioning autism. Results found that pedantic speech was common in the patients with AS and may help differentiate AS from high-functioning autism. (Author/CR)

  15. Functional cooperation between FACT and MCM is coordinated with cell cycle and differential complex formation

    Microsoft Academic Search

    Bertrand Chin-Ming Tan; Hsuan Liu; Chih-Li Lin; Sheng-Chung Lee

    2010-01-01

    BACKGROUND: Functional cooperation between FACT and the MCM helicase complex constitutes an integral step during DNA replication initiation. However, mode of regulation that underlies the proper functional interaction of FACT and MCM is poorly understood. METHODS & RESULTS: Here we present evidence indicating that such interaction is coordinated with cell cycle progression and differential complex formation. We first demonstrate the

  16. Systematically Differentiating Functions for Alternatively Spliced Isoforms through Integrating RNA-seq Data

    PubMed Central

    Menon, Rajasree; Wen, Yuchen; Omenn, Gilbert S.; Kretzler, Matthias; Guan, Yuanfang

    2013-01-01

    Integrating large-scale functional genomic data has significantly accelerated our understanding of gene functions. However, no algorithm has been developed to differentiate functions for isoforms of the same gene using high-throughput genomic data. This is because standard supervised learning requires ‘ground-truth’ functional annotations, which are lacking at the isoform level. To address this challenge, we developed a generic framework that interrogates public RNA-seq data at the transcript level to differentiate functions for alternatively spliced isoforms. For a specific function, our algorithm identifies the ‘responsible’ isoform(s) of a gene and generates classifying models at the isoform level instead of at the gene level. Through cross-validation, we demonstrated that our algorithm is effective in assigning functions to genes, especially the ones with multiple isoforms, and robust to gene expression levels and removal of homologous gene pairs. We identified genes in the mouse whose isoforms are predicted to have disparate functionalities and experimentally validated the ‘responsible’ isoforms using data from mammary tissue. With protein structure modeling and experimental evidence, we further validated the predicted isoform functional differences for the genes Cdkn2a and Anxa6. Our generic framework is the first to predict and differentiate functions for alternatively spliced isoforms, instead of genes, using genomic data. It is extendable to any base machine learner and other species with alternatively spliced isoforms, and shifts the current gene-centered function prediction to isoform-level predictions. PMID:24244129

  17. Decellularized tracheal extracellular matrix supports epithelial migration, differentiation, and function.

    PubMed

    Kutten, Johannes C; McGovern, David; Hobson, Christopher M; Luffy, Sarah A; Nieponice, Alejandro; Tobita, Kimimasa; Francis, Richard J; Reynolds, Susan D; Isenberg, Jeffrey S; Gilbert, Thomas W

    2015-01-01

    Tracheal loss is a source of significant morbidity for affected patients with no acceptable solution. Interest in engineering tracheal transplants has created a demand for small animal models of orthotopic tracheal transplantation. Here, we examine the use of a decellularized graft in a murine model of tracheal replacement. Fresh or decellularized tracheas harvested from age-matched female donor C57BL/6 mice were transplanted into syngeneic recipients. Tracheas were decellularized using repeated washes of water, 3% Triton X-100, and 3?M NaCl under cyclic pressure changes, followed by disinfection with 0.1% peracetic acid/4% ethanol, and terminal sterilization by gamma irradiation. Tracheas were explanted for immunolabeling at 1, 4, and 8 weeks following surgery. Video microscopy and computed tomography were performed to assess function and structure. Decellularized grafts supported complete reepithelialization by 8 weeks and motile cilia were observed. Cartilaginous portions of the trachea were maintained in mice receiving fresh transplants, but repopulation of the cartilage was not seen in mice receiving decellularized transplants. We observed superior postsurgical survival, weight gain, and ciliary function in mice receiving fresh transplants compared with those receiving decellularized transplants. The murine orthotopic tracheal transplant provides an appropriate model to assess the repopulation and functional regeneration of decellularized tracheal grafts. PMID:24980864

  18. Differential functional effects of biomaterials on dendritic cell maturation.

    PubMed

    Park, Jaehyung; Babensee, Julia E

    2012-10-01

    The immunological outcome of dendritic cell (DC) treatment with different biomaterials was assessed to demonstrate the range of DC phenotypes induced by biomaterials commonly used in combination products. Immature DCs (iDCs) were derived from human peripheral blood monocytes, and treated with different biomaterial films of alginate, agarose, chitosan, hyaluronic acid (HA), or 75:25 poly(lactic-co-glycolic acid) (PLGA) and a comprehensive battery of phenotypic functional outcomes was assessed. Different levels of functional changes in DC phenotype were observed depending on the type of biomaterial films used to treat the DCs. Treatment of DCs with PLGA or chitosan films supported DC maturation, with higher levels of DC allostimulatory capacity, pro-inflammatory cytokine release, and expression of CD80, CD86, CD83, HLA-DQ and CD44 compared with iDCs, and lower endocytic ability compared with iDCs. Alginate film induced pro-inflammatory cytokine release from DCs at levels higher than from iDCs. Dendritic cells treated with HA film expressed lower levels of CD40, CD80, CD86 and HLA-DR compared with iDCs. They also exhibited lower endocytic ability and CD44 expression than iDCs, possibly due to an insolubilized (cross-linked) form of high molecular weight HA. Interestingly, treatment of DCs with agarose film maintained the DC functional phenotype at levels similar to iDCs except for CD44 expression, which was lower than that of iDCs. Taken together, these results can provide selection criteria for biomaterials to be used in immunomodulating applications and can inform potential outcomes of biomaterials within combination products on associated immune responses as desired by the application. PMID:22705044

  19. Diverse Broad-Host-Range Plasmids from Freshwater Carry Few Accessory Genes

    PubMed Central

    Sen, Diya; Yano, Hirokazu; Bauer, Matthew L.; Rogers, Linda M.; Van der Auwera, Geraldine A.

    2013-01-01

    Broad-host-range self-transferable plasmids are known to facilitate bacterial adaptation by spreading genes between phylogenetically distinct hosts. These plasmids typically have a conserved backbone region and a variable accessory region that encodes host-beneficial traits. We do not know, however, how well plasmids that do not encode accessory functions can survive in nature. The goal of this study was to characterize the backbone and accessory gene content of plasmids that were captured from freshwater sources without selecting for a particular phenotype or cultivating their host. To do this, triparental matings were used such that the only required phenotype was the plasmid's ability to mobilize a nonconjugative plasmid. Based on complete genome sequences of 10 plasmids, only 5 carried identifiable accessory gene regions, and none carried antibiotic resistance genes. The plasmids belong to four known incompatibility groups (IncN, IncP-1, IncU, and IncW) and two potentially new groups. Eight of the plasmids were shown to have a broad host range, being able to transfer into alpha-, beta-, and gammaproteobacteria. Because of the absence of antibiotic resistance genes, we resampled one of the sites and compared the proportion of captured plasmids that conferred antibiotic resistance to their hosts with the proportion of such plasmids captured from the effluent of a local wastewater treatment plant. Few of the captured plasmids from either site encoded antibiotic resistance. A high diversity of plasmids that encode no or unknown accessory functions is thus readily found in freshwater habitats. The question remains how the plasmids persist in these microbial communities. PMID:24096417

  20. 21 CFR 878.4400 - Electrosurgical cutting and coagulation device and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... false Electrosurgical cutting and coagulation device and accessories. 878.4400...4400 Electrosurgical cutting and coagulation device and accessories. (a) Identification. An electrosurgical cutting and coagulation device and accessories is a...

  1. 21 CFR 878.4400 - Electrosurgical cutting and coagulation device and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... false Electrosurgical cutting and coagulation device and accessories. 878.4400...4400 Electrosurgical cutting and coagulation device and accessories. (a) Identification. An electrosurgical cutting and coagulation device and accessories is a...

  2. 21 CFR 878.4400 - Electrosurgical cutting and coagulation device and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... false Electrosurgical cutting and coagulation device and accessories. 878.4400...4400 Electrosurgical cutting and coagulation device and accessories. (a) Identification. An electrosurgical cutting and coagulation device and accessories is a...

  3. 21 CFR 878.4400 - Electrosurgical cutting and coagulation device and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... false Electrosurgical cutting and coagulation device and accessories. 878.4400...4400 Electrosurgical cutting and coagulation device and accessories. (a) Identification. An electrosurgical cutting and coagulation device and accessories is a...

  4. 21 CFR 878.4400 - Electrosurgical cutting and coagulation device and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... false Electrosurgical cutting and coagulation device and accessories. 878.4400...4400 Electrosurgical cutting and coagulation device and accessories. (a) Identification. An electrosurgical cutting and coagulation device and accessories is a...

  5. Simon Effect with and without Awareness of the Accessory Stimulus

    ERIC Educational Resources Information Center

    Treccani, Barbara; Umilta, Carlo; Tagliabue, Mariaelena

    2006-01-01

    The authors investigated whether a Simon effect could be observed in an accessory-stimulus Simon task when participants were unaware of the task-irrelevant accessory cue. In Experiment 1A a central visual target was accompanied by a suprathreshold visual lateral cue. A regular Simon effect (i.e., faster cue-response corresponding reaction times…

  6. Accessory bronchus in a patient with chronic cough.

    PubMed

    Rodríguez-Fuentes, Raúl; Esparza, Edgar A; Macías, Marco P; Quiroz-Castro, Oscar

    2013-04-01

    The accessory bronchus involving the trachea or main bronchi is very rare. In this report, we present images of an accessory bronchus, detected by computed tomography scan and flexible bronchoscopy. Our patient was suffering from persistent productive cough and had normal chest x-ray. We review the literature to establish relationship between our patient's symptoms and this congenital anomaly. PMID:23609250

  7. The subcellular distribution and function of MTA1 in cancer differentiation

    PubMed Central

    Zhang, Ying; Chang, Yanan; Zhang, Jinlong; Wang, Jia; Li, Chunxiao; Liu, Huan; Zhao, Mei; Lin, Chen; Zhan, Qimin; Huang, Changzhi; Qian, Haili

    2014-01-01

    The functions and mechanisms of metastasis-associated protein 1 (MTA1) in cancer progression are still unclear due to a lagged recognition of the subcellular localization. In the present study, using multiple molecular technologies we confirmed for the first time that MTA1 localizes to the nucleus, cytoplasm and nuclear envelope. MTA1 is primarily localized in the nucleus of normal adult tissues but in the cytoplasm of embryonic tissues. While in colon cancer, both distributions have been described. Further investigation revealed that MTA1 localizes on the nuclear envelope in a translocated promoter region (TPR)-dependent manner, while in the cytoplasm, MTA1 shows an obvious localization on microtubules. Both nuclear and cytoplasmic MTA1 are associated with cancer progression. However, these functions may be associated with different mechanisms because only nuclear MTA1 has been associated with cancer differentiation. Overexpression of MTA1 in HCT116 cells inhibited differentiation and promoted proliferation, whereas MTA1 knockdown resulted in cell differentiation and death. Theses results not only suggest that nuclear MTA1 is a good marker for cancer differentiation diagnosis and a potential target for the treatment of cancers but also reveal the necessity to differentially examine the functions of nuclear and cytoplasmic MTA1. PMID:24970816

  8. CD4+ T helper 2 cells – microbial triggers, differentiation requirements and effector functions

    PubMed Central

    Okoye, Isobel S; Wilson, Mark S

    2011-01-01

    Over the past 10 years we have made great strides in our understanding of T helper cell differentiation, expansion and effector functions. Within the context of T helper type 2 (Th2) cell development, novel innate-like cells with the capacity to secrete large amounts of interleukin-5 (IL-5), IL-13 and IL-9 as well as IL-4-producing and antigen-processing basophils have (re)-emerged onto the type 2 scene. To what extent these new players influence ??+ CD4+ Th2 cell differentiation is discussed throughout this appraisal of the current literature. We highlight the unique features of Th2 cell development, highlighting the three necessary signals, T-cell receptor ligation, co-stimulation and cytokine receptor ligation. Finally, putting these into context, microbial and allergenic properties that trigger Th2 cell differentiation and how these influence Th2 effector function are discussed and questioned. PMID:22043920

  9. Possibility of Undifferentiated Human Thigh Adipose Stem Cells Differentiating into Functional Hepatocytes

    PubMed Central

    Lee, Kuk Han; Kim, Min Ho; Kim, Jun Pyo; Lee, Seung Jae; Yoon, Jinah

    2012-01-01

    Background This study aimed to investigate the possibility of isolating mesenchymal stem cells (MSCs) from human thigh adipose tissue and the ability of human thigh adipose stem cells (HTASCs) to differentiate into hepatocytes. Methods The adipose-derived stem cells (ADSCs) were isolated from thigh adipose tissue. Growth factors, cytokines, and hormones were added to the collagen coated dishes to induce the undifferentiated HTASCs to differentiate into hepatocyte-like cells. To confirm the experimental results, the expression of hepatocyte-specific markers on undifferentiated and differentiated HTASCs was analyzed using reverse transcription polymerase chain reaction and immunocytochemical staining. Differentiation efficiency was evaluated using functional tests such as periodic acid schiff (PAS) staining and detection of the albumin secretion level using enzyme-linked immunosorbent assay (ELISA). Results The majority of the undifferentiated HTASCs were changed into a more polygonal shape showing tight interactions between the cells. The differentiated HTASCs up-regulated mRNA of hepatocyte markers. Immunocytochemical analysis showed that they were intensely stained with anti-albumin antibody compared with undifferentiated HTASCs. PAS staining showed that HTASCs submitted to the hepatocyte differentiation protocol were able to more specifically store glycogen than undifferentiated HTASCs, displaying a purple color in the cytoplasm of the differentiated HTASCs. ELISA analyses showed that differentiated HTASCs could secrete albumin, which is one of the hepatocyte markers. Conclusions MSCs were islolated from human thigh adipose tissue differentiate to heapatocytes. The source of ADSCs is not only abundant abdominal adipose tissue, but also thigh adipose tissue for cell therapy in liver regeneration and tissue regeneration. PMID:23233883

  10. G protein-coupled receptor accessory proteins and signaling: pharmacogenomic insights.

    PubMed

    Thompson, Miles D; Cole, David E C; Jose, Pedro A; Chidiac, Peter

    2014-01-01

    The identification and characterization of the genes encoding G protein-coupled receptors (GPCRs) and the proteins necessary for the processes of ligand binding, GPCR activation, inactivation, and receptor trafficking to the membrane are discussed in the context of human genetic disease. In addition to functional GPCR variants, the identification of genetic disruptions affecting proteins necessary to GPCR functions have provided insights into the function of these pathways. Gs? and G? subunit polymorphisms have been found to result in complex phenotypes. Disruptions in accessory proteins that normally modify or organize heterotrimeric G-protein coupling may also result in disease states. These include the contribution of variants of the regulator of G protein signaling (RGS) protein to hypertension; the role variants of the activator of G protein signaling (AGS) proteins to phenotypes (such as the type III AGS8 variant to hypoxia); the contribution of G protein-coupled receptor kinase (GRK) proteins, such as GRK4, in disorders such as hypertension. The role of accessory proteins in GPCR structure and function is discussed in the context of genetic disorders associated with disruption of the genes that encode them. An understanding of the pharmacogenomics of GPCR and accessory protein signaling provides the basis for examining both GPCR pharmacogenetics and the genetics of monogenic disorders that result from disruption of given receptor systems. PMID:25150869

  11. Linguistic Complexity, Schematic Representations, and Differential Item Functioning for English Language Learners in Math Tests

    ERIC Educational Resources Information Center

    Martiniello, Maria

    2009-01-01

    This article examines nonmathematical linguistic complexity as a source of differential item functioning (DIF) in math word problems for English language learners (ELLs). Specifically, this study investigates the relationship between item measures of linguistic complexity, nonlinguistic forms of representation and DIF measures based on item…

  12. An Odds Ratio Approach for Assessing Differential Distractor Functioning Effects under the Nominal Response Model

    ERIC Educational Resources Information Center

    Penfield, Randall D.

    2008-01-01

    Investigations of differential distractor functioning (DDF) can provide valuable information concerning the location and possible causes of measurement invariance within a multiple-choice item. In this article, I propose an odds ratio estimator of the DDF effect as modeled under the nominal response model. In addition, I propose a simultaneous…

  13. Assessment of Differential Item Functioning under Cognitive Diagnosis Models: The DINA Model Example

    ERIC Educational Resources Information Center

    Li, Xiaomin; Wang, Wen-Chung

    2015-01-01

    The assessment of differential item functioning (DIF) is routinely conducted to ensure test fairness and validity. Although many DIF assessment methods have been developed in the context of classical test theory and item response theory, they are not applicable for cognitive diagnosis models (CDMs), as the underlying latent attributes of CDMs are…

  14. A Robust Outlier Approach to Prevent Type I Error Inflation in Differential Item Functioning

    ERIC Educational Resources Information Center

    Magis, David; De Boeck, Paul

    2012-01-01

    The identification of differential item functioning (DIF) is often performed by means of statistical approaches that consider the raw scores as proxies for the ability trait level. One of the most popular approaches, the Mantel-Haenszel (MH) method, belongs to this category. However, replacing the ability level by the simple raw score is a source…

  15. Determinants of Differential Item Functioning in an Elementary Mathematics Test with Accommodations

    ERIC Educational Resources Information Center

    Chae, Soo Eun; Kim, Doyoung; Han, Jae-Ho

    2012-01-01

    Those items or test characteristics that are likely to result in differential item functioning (DIF) across accommodated test forms in statewide tests have received little attention. An examination of elementary-level student performance across accommodated test forms in a large-scale mathematics assessment revealed DIF variations by grades,…

  16. Detecting Native Language Group Differences at the Subskills Level of Reading: A Differential Skill Functioning Approach

    ERIC Educational Resources Information Center

    Li, Hongli; Suen, Hoi K.

    2013-01-01

    Differential skill functioning (DSF) exists when examinees from different groups have different probabilities of successful performance in a certain subskill underlying the measured construct, given that they have the same ability on the overall construct. Using a DSF approach, this study examined the differences between two native language…

  17. Correlates of Communalities as Matching Variables in Differential Item Functioning Analyses

    ERIC Educational Resources Information Center

    Yildirim, Huseyin H.; Yildirim, Selda

    2011-01-01

    Multivariate matching in Differential Item Functioning (DIF) analyses may contribute to understand the sources of DIF. In this context, detecting appropriate additional matching variables is a crucial issue. This present article argues that the variables which are correlated with communalities in item difficulties can be used as an additional…

  18. Geometric interplay between function subspaces and their rings of differential operators

    Microsoft Academic Search

    Rikard Bogvadand; Rolf Kallstrom

    We study, in the setting of algebraic varieties, finite-dimensional spaces of functions V that are invariant under a ring DV of differential operators, and give conditions under which DV acts irreducibly. We show how this problem, originally formulated in physics (20, 29), is related to the study of principal parts bundles and Weierstrass points (13, 22), including a detailed study

  19. Parent Ratings of ADHD Symptoms: Generalized Partial Credit Model Analysis of Differential Item Functioning across Gender

    ERIC Educational Resources Information Center

    Gomez, Rapson

    2012-01-01

    Objective: Generalized partial credit model, which is based on item response theory (IRT), was used to test differential item functioning (DIF) for the "Diagnostic and Statistical Manual of Mental Disorders" (4th ed.), inattention (IA), and hyperactivity/impulsivity (HI) symptoms across boys and girls. Method: To accomplish this, parents completed…

  20. Parent Ratings of ADHD Symptoms: Differential Symptom Functioning across Malaysian Malay and Chinese Children

    ERIC Educational Resources Information Center

    Gomez, Rapson; Vance, Alasdair

    2008-01-01

    This study examined differential symptom functioning (DSF) in ADHD symptoms across Malay and Chinese children in Malaysia. Malay (N = 571) and Chinese (N = 254) parents completed the Disruptive Behavior Rating Scale, which lists the DSM-IV ADHD symptoms. DSF was examined using the multiple indicators multiple causes (MIMIC) structural equation…

  1. A Comparison of Four Methods for Detecting Differential Item Functioning in Ordered Response Items

    ERIC Educational Resources Information Center

    Kristjansson, Elizabeth; Aylesworth, Richard; Mcdowell, Ian; Zumbo, Bruno D.

    2005-01-01

    Item bias is a major threat to measurement validity. Methods for detecting differential item functioning (DIF) are now commonly used to identify potentially biased items. DIF detection methods for dichotomous items are well developed, but those for ordinal items are less well developed. In this article, the authors compare four methods for…

  2. Envy: Functional specificity and sex-differentiated design features Danielle J. DelPriore a,

    E-print Network

    Cooper, Brenton G.

    Available online xxxx Keywords: Sex differences Envy Emotions Evolutionary psychology a b s t r a c t In twoEnvy: Functional specificity and sex-differentiated design features Danielle J. DelPriore a, , Sarah E. Hill a , David M. Buss b a Department of Psychology, Texas Christian University, United States

  3. Envy: Functional specificity and sex-differentiated design features Danielle J. DelPriore a,

    E-print Network

    Pillow, Jonathan

    Available online 25 April 2012 Keywords: Sex differences Envy Emotions Evolutionary psychology a b s t r a cEnvy: Functional specificity and sex-differentiated design features Danielle J. DelPriore a, , Sarah E. Hill a , David M. Buss b a Department of Psychology, Texas Christian University, United States

  4. Investigating Gender Differential Item Functioning across Countries and Test Languages for PISA Science Items

    ERIC Educational Resources Information Center

    Le, Luc T.

    2009-01-01

    This study uses PISA cycle 3 field trial data to investigate the relationships between gender differential item functioning (DIF) across countries and test languages for science items and their formats and the four other dimensions defined in PISA framework: focus, context, competency, and scientific knowledge. The data used were collected from 60…

  5. Identification of Differential Item Functioning in Multiple-Group Settings: A Multivariate Outlier Detection Approach

    ERIC Educational Resources Information Center

    Magis, David; De Boeck, Paul

    2011-01-01

    We focus on the identification of differential item functioning (DIF) when more than two groups of examinees are considered. We propose to consider items as elements of a multivariate space, where DIF items are outlying elements. Following this approach, the situation of multiple groups is a quite natural case. A robust statistics technique is…

  6. Group-Specific Effects of Matching Subtest Contamination on the Identification of Differential Item Functioning

    ERIC Educational Resources Information Center

    Keiffer, Elizabeth Ann

    2011-01-01

    A differential item functioning (DIF) simulation study was conducted to explore the type and level of impact that contamination had on type I error and power rates in DIF analyses when the suspect item favored the same or opposite group as the DIF items in the matching subtest. Type I error and power rates were displayed separately for the…

  7. Assessment of Differential Item Functioning in Testlet-Based Items Using the Rasch Testlet Model

    ERIC Educational Resources Information Center

    Wang, Wen-Chung; Wilson, Mark

    2005-01-01

    This study presents a procedure for detecting differential item functioning (DIF) for dichotomous and polytomous items in testlet-based tests, whereby DIF is taken into account by adding DIF parameters into the Rasch testlet model. Simulations were conducted to assess recovery of the DIF and other parameters. Two independent variables, test type…

  8. Lyapunov functions for quadratic differential equations with applications to adaptive control

    Microsoft Academic Search

    G. Luders; K. Narendra

    1972-01-01

    Conditions are derived for the existence of quadratic Lyapunov functions for vector differential equations with quadratic terms. These conditions are used to establish a set of nonlinear equations for which the null solution is asymptotically stable in the whole. Many of the recent results in the stability of model reference adaptive systems are particular cases of these general conditions.

  9. Differential Item Functioning with a Criterion-Referenced Test: Use of Limited Closed-Interval Measures.

    ERIC Educational Resources Information Center

    Oshima, T. C.; And Others

    The purpose of this study was to introduce a procedure to detect differential item functioning (DIF) particularly suitable for criterion-referenced tests and to demonstrate how this approach would affect the identification of DIF items using real data sets. The procedure based on item response theory (IRT) assesses DIF at a limited closed interval…

  10. The Effect of Differential Item Functioning in Anchor Items on Population Invariance of Equating

    ERIC Educational Resources Information Center

    Huggins, Anne Corinne

    2014-01-01

    Invariant relationships in the internal mechanisms of estimating achievement scores on educational tests serve as the basis for concluding that a particular test is fair with respect to statistical bias concerns. Equating invariance and differential item functioning are both concerned with invariant relationships yet are treated separately in the…

  11. Reduction principle and dynamic behaviors for a class of partial functional differential equations

    Microsoft Academic Search

    Mostafa Adimy; Abdelhai Elazzouzi; Khalil Ezzinbi

    2009-01-01

    We investigate the dynamic of solutions in the ?-norm for some nonhomogeneous linear partial functional differential equations. We suppose that the undelayed homogeneous part is the infinitesimal generator of an analytic semigroup, and the delayed part is continuous with respect to fractional powers of the generator. We establish a reduction principle for the infinite dimensional system in order to reduce

  12. Existence of solutions for semilinear neutral stochastic functional differential equations with nonlocal conditions

    Microsoft Academic Search

    P. Balasubramaniam; J. Y. Park; A. Vincent Antony Kumar

    2009-01-01

    In this paper, by using fractional power of operators and Sadovskii fixed point theorem, the existence of mild and strong solutions of semilinear neutral functional differential evolution equations with nonlocal conditions is studied. The results are a generalization and continuation of the recent results on this issue. An example is provided to illustrate the theory.

  13. Differential Selection on Carotenoid Biosynthesis Genes as a Function of Gene Position in the Metabolic Pathway

    E-print Network

    Paris-Sud XI, Université de

    Differential Selection on Carotenoid Biosynthesis Genes as a Function of Gene Position in controlling metabolic fluxes. This hypothesis was tested in the carotenoid biosynthesis pathway using distributed along the carotenoid biosynthesis pathway, IPI, PDS, CRTISO, LCYB, LCYE, CHXE and ZEP, were

  14. Differential Item Functioning Detection Using the Multiple Indicators, Multiple Causes Method with a Pure Short Anchor

    ERIC Educational Resources Information Center

    Shih, Ching-Lin; Wang, Wen-Chung

    2009-01-01

    The multiple indicators, multiple causes (MIMIC) method with a pure short anchor was proposed to detect differential item functioning (DIF). A simulation study showed that the MIMIC method with an anchor of 1, 2, 4, or 10 DIF-free items yielded a well-controlled Type I error rate even when such tests contained as many as 40% DIF items. In general,…

  15. Traffic Flows and Traffic Jams: From Kinetic Models to Functional-Differential Equations

    E-print Network

    Illner, Reinhard

    as a Fundamental Diagram! . . . and defines a scalar conservation law. Reinhard Illner, Victoria Traffic FlowsTraffic Flows and Traffic Jams: From Kinetic Models to Functional-Differential Equations Reinhard Illner, Victoria Austin Winter School, February 2013 Reinhard Illner, Victoria Traffic Flows and Traffic

  16. Assessing the Item Response Theory with Covariate (IRT-C) Procedure for Ascertaining Differential Item Functioning

    ERIC Educational Resources Information Center

    Tay, Louis; Vermunt, Jeroen K.; Wang, Chun

    2013-01-01

    We evaluate the item response theory with covariates (IRT-C) procedure for assessing differential item functioning (DIF) without preknowledge of anchor items (Tay, Newman, & Vermunt, 2011). This procedure begins with a fully constrained baseline model, and candidate items are tested for uniform and/or nonuniform DIF using the Wald statistic.…

  17. A Monte Carlo Study Investigating Missing Data, Differential Item Functioning, and Effect Size

    ERIC Educational Resources Information Center

    Garrett, Phyllis

    2009-01-01

    The use of polytomous items in assessments has increased over the years, and as a result, the validity of these assessments has been a concern. Differential item functioning (DIF) and missing data are two factors that may adversely affect assessment validity. Both factors have been studied separately, but DIF and missing data are likely to occur…

  18. The MIMIC Method with Scale Purification for Detecting Differential Item Functioning

    ERIC Educational Resources Information Center

    Wang, Wen-Chung; Shih, Ching-Lin; Yang, Chih-Chien

    2009-01-01

    This study implements a scale purification procedure onto the standard MIMIC method for differential item functioning (DIF) detection and assesses its performance through a series of simulations. It is found that the MIMIC method with scale purification (denoted as M-SP) outperforms the standard MIMIC method (denoted as M-ST) in controlling…

  19. An Investigation of the Likelihood Ratio Test for Detection of Differential Item Functioning.

    ERIC Educational Resources Information Center

    Cohen, Allan S.; And Others

    1996-01-01

    Type I error rates for the likelihood ratio test for detecting differential item functioning (DIF) were investigated using Monte Carlo simulations. Type I error rates for the two-parameter model were within theoretically expected values at each alpha level, but those for the three-parameter model were not. (SLD)

  20. An Introduction to Missing Data in the Context of Differential Item Functioning

    ERIC Educational Resources Information Center

    Banks, Kathleen

    2015-01-01

    This article introduces practitioners and researchers to the topic of missing data in the context of differential item functioning (DIF), reviews the current literature on the issue, discusses implications of the review, and offers suggestions for future research. A total of nine studies were reviewed. All of these studies determined what effect…

  1. Detection of Differential Item Functioning Using Lagrange Multiplier Tests. Research Report 96-02.

    ERIC Educational Resources Information Center

    Glas, Cees A. W.

    In this paper it is shown that differential item functioning can be evaluated using the Lagrange multiplier test or C. R. Rao's efficient score test. The test is presented in the framework of a number of item response theory (IRT) models such as the Rasch model, the one-parameter logistic model, the two-parameter logistic model, the generalized…

  2. Counting Snakes, Differentiating the Tangent Function, and Investigating the Bernoulli-Euler Triangle

    E-print Network

    Reiter, Harold

    Counting Snakes, Differentiating the Tangent Function, and Investigating the Bernoulli. One is a family of permutations of finite sets of integers, called snakes. The second is the tangent array of numbers called the Bernoulli-Euler triangle. Snakes and Up-Down Permutations. What are Snakes

  3. Counting Snakes, Differentiating the Tangent Function, and Investigating the Bernoulli-Euler Triangle

    E-print Network

    Reiter, Harold

    Counting Snakes, Differentiating the Tangent Function, and Investigating the Bernoulli is a family of permutations of finite sets of integers, called snakes. The second is the tangent and secant of numbers called the Bernoulli-Euler triangle. Snakes and Up-Down Permutations. What are Snakes and What

  4. A volumetric integral radial basis function method for time-dependent partial differential equations. I. Formulation

    Microsoft Academic Search

    E. J. Kansa; H. Power; G. E. Fasshauer; L. Ling

    2004-01-01

    A strictly conservative volume integral formulation of the time dependent conservation equations in terms of meshless radial basis functions (RBFs) is presented. Rotational and translational transformations are considered that simplify the partial differential equations (PDEs) to be solved. As a result, the solutions that are represented at a finite sample of knots, x??\\\\???Rd, are permitted to move as the system

  5. Evaluation of Two Types of Differential Item Functioning in Factor Mixture Models with Binary Outcomes

    ERIC Educational Resources Information Center

    Lee, HwaYoung; Beretvas, S. Natasha

    2014-01-01

    Conventional differential item functioning (DIF) detection methods (e.g., the Mantel-Haenszel test) can be used to detect DIF only across observed groups, such as gender or ethnicity. However, research has found that DIF is not typically fully explained by an observed variable. True sources of DIF may include unobserved, latent variables, such as…

  6. Icariin induces mouse embryonic stem cell differentiation into beating functional cardiomyocytes

    Microsoft Academic Search

    Xiaodong Sun; Xiuwei Sun; Xiudong Jin; Xiaoli Zhang; Chunling Liu; Lei Lei; Lianhong Jin; Huiwen Liu

    2011-01-01

    Icariin, the primary active component of Epimedium extracts, has recently been shown to induce cardiomyocyte differentiation\\u000a of murine embryonic stem (mES) cells in vitro. However, as these cardiomyocytes were not functionally characterized, the potential\\u000a application of icariin-induced cardiomyocytes in clinical practice remains unclear. Therefore, in this study, we characterized\\u000a the structure and function of icariin-induced cardiomyocytes to evaluate their potential

  7. Functional Role of Mst1/Mst2 in Embryonic Stem Cell Differentiation

    PubMed Central

    Li, Peng; Chen, Ying; Mak, Kinglun Kingston; Wong, Chun Kwok; Wang, Chi Chiu; Yuan, Ping

    2013-01-01

    The Hippo pathway is an evolutionary conserved pathway that involves cell proliferation, differentiation, apoptosis and organ size regulation. Mst1 and Mst2 are central components of this pathway that are essential for embryonic development, though their role in controlling embryonic stem cells (ES cells) has yet to be exploited. To further understand the Mst1/Mst2 function in ES cell pluripotency and differentiation, we derived Mst1/Mst2 double knockout (Mst-/-) ES cells to completely perturb Hippo signaling. We found that Mst-/- ES cells express higher level of Nanog than wild type ES cells and show differentiation resistance after LIF withdrawal. They also proliferate faster than wild type ES cells. Although Mst-/- ES cells can form embryoid bodies (EBs), their differentiation into tissues of three germ layers is distorted. Intriguingly, Mst-/- ES cells are unable to form teratoma. Mst-/- ES cells can differentiate into mesoderm lineage, but further differentiation to cardiac lineage cells is significantly affected. Microarray analysis revealed that ligands of non-canonical Wnt signaling, which is critical for cardiac progenitor specification, are significantly repressed in Mst-/- EBs. Taken together our results showed that Mst1/Mst2 are required for proper cardiac lineage cell development and teratoma formation. PMID:24224013

  8. Novel Functional Changes during Podocyte Differentiation: Increase of Oxidative Resistance and H-Ferritin Expression

    PubMed Central

    Balogh, Enik?; Arosio, Paolo; Király, Gábor; Nagy, Gábor; Tánczos, Bence; Balla, György; Balla, József; Bánfalvi, Gáspár

    2014-01-01

    Podocytes are highly specialized, arborized epithelial cells covering the outer surface of the glomerular tuft in the kidney. Terminally differentiated podocytes are unable to go through cell division and hereby they are lacking a key property for regeneration after a toxic injury. Podocytes are long-lived cells but, to date, little is known about the mechanisms that support their stress resistance. Our aim was to investigate whether the well-known morphological changes during podocyte differentiation are accompanied by changes in oxidative resistance in a manner that could support their long-term survival. We used a conditionally immortalized human podocyte cell line to study the morphological and functional changes during differentiation. We followed the differentiation process for 14 days by time-lapse microscopy. During this period nondifferentiated podocytes gradually transformed into large, nonproliferating, frequently multinucleated cells, with enlarged nuclei and opened chromatin structure. We observed that differentiated podocytes were highly resistant to oxidants such as H2O2 and heme when applied separately or in combination, whereas undifferentiated cells were prone to such challenges. Elevated oxidative resistance of differentiated podocytes was associated with increased activities of antioxidant enzymes and H-ferritin expression. Immunohistochemical analysis of normal human kidney specimens revealed that podocytes highly express H-ferritin in vivo as well. PMID:25097723

  9. Krüppel-like factor 4 is involved in functional differentiation of testicular Sertoli cells

    PubMed Central

    Godmann, Maren; Katz, Jonathan P.; Guillou, Florian; Simoni, Manuela; Kaestner, Klaus H.; Behr, Rüdiger

    2008-01-01

    Krüppel-like factor 4 (KLF4) is a pleiotropic zinc finger transcription factor that regulates genes being involved in differentiation and cell-cycle control. Knock out studies revealed a critical function for KLF4 in the terminal differentiation of many epithelial cells. In testicular Sertoli cells, Klf4 is strongly inducible by the glycoprotein Follicle stimulating hormone (FSH). Since KLF4 is essential for postnatal survival in mice, we deleted Klf4 specifically in Sertoli cells using the Cre/loxP system. Importantly, around postnatal day 18, a critical period of terminal Sertoli cell differentiation, mutant seminiferous tubules exhibited a disorganized germinal epithelium and delayed lumen formation. The ultrastructural finding of highly vacuolized Sertoli cell cytoplasm and the identification of differentially expressed genes, which are known to play roles during vesicle transport and fusion or for maintenance of the differentiated cell state, suggest impaired apical secretion of the Sertoli cell. Interestingly, a high proportion of all identified genes was localized in a small subregion of chromosome 7 suggesting coordinated regulation. Intriguingly, adult mutant mice are fertile and show normal testicular morphology, although the testosterone levels are decreased. In summary, KLF4 plays a significant role for proper and timely Sertoli cell differentiation in pubertal mice. PMID:18243172

  10. Lhx1 Controls Terminal Differentiation and Circadian Function of the Suprachiasmatic Nucleus

    PubMed Central

    Bedont, Joseph L.; LeGates, Tara A.; Slat, Emily A.; Byerly, Mardi S.; Wang, Hong; Hu, Jianfei; Rupp, Alan C.; Qian, Jiang; Wong, G. William; Herzog, Erik D.; Hattar, Samer; Blackshaw, Seth

    2014-01-01

    SUMMARY Vertebrate circadian rhythms are organized by the hypothalamic suprachiasmatic nucleus (SCN). Despite its physiological importance, SCN development is poorly understood. Here, we show that Lim homeodomain transcription factor 1 (Lhx1) is essential for terminal differentiation and function of the SCN. Deletion of Lhx1 in the developing SCN results in loss of SCN-enriched neuropeptides involved in synchronization and coupling to downstream oscillators, among other aspects of circadian function. Intact, albeit damped, clock gene expression rhythms persist in Lhx1-deficient SCN; however, circadian activity rhythms are highly disorganized and susceptible to surprising changes in period, phase, and consolidation following neuropeptide infusion. Our results identify a factor required for SCN terminal differentiation. In addition, our in vivo study of combinatorial SCN neuropeptide disruption uncovered synergies among SCN-enriched neuropeptides in regulating normal circadian function. These animals provide a platform for studying the central oscillator's role in physiology and cognition. PMID:24767996

  11. Functional maintenance of differentiated embryoid bodies in microfluidic systems: a platform for personalized medicine.

    PubMed

    Guven, Sinan; Lindsey, Jennifer S; Poudel, Ishwari; Chinthala, Sireesha; Nickerson, Michael D; Gerami-Naini, Behzad; Gurkan, Umut A; Anchan, Raymond M; Demirci, Utkan

    2015-03-01

    Hormone replacement therapies have become important for treating diseases such as premature ovarian failure or menopausal complications. The clinical use of bioidentical hormones might significantly reduce some of the potential risks reportedly associated with the use of synthetic hormones. In the present study, we demonstrate the utility and advantage of a microfluidic chip culture system to enhance the development of personalized, on-demand, treatment modules using embryoid bodies (EBs). Functional EBs cultured on microfluidic chips represent a platform for personalized, patient-specific treatment cassettes that can be cryopreserved until required for treatment. We assessed the viability, differentiation, and functionality of EBs cultured and cryopreserved in this system. During extended microfluidic culture, estradiol, progesterone, testosterone, and anti-müllerian hormone levels were measured, and the expression of differentiated steroidogenic cells was confirmed by immunocytochemistry assay for the ovarian tissue markers anti-müllerian hormone receptor type II, follicle-stimulating hormone receptor, and inhibin ?-A and the estrogen biosynthesis enzyme aromatase. Our studies showed that under microfluidic conditions, differentiated steroidogenic EBs continued to secrete estradiol and progesterone at physiologically relevant concentrations (30-120 pg/ml and 150-450 pg/ml, respectively) for up to 21 days. Collectively, we have demonstrated for the first time the feasibility of using a microfluidic chip system with continuous flow for the differentiation and extended culture of functional steroidogenic stem cell-derived EBs, the differentiation of EBs into cells expressing ovarian antigens in a microfluidic system, and the ability to cryopreserve this system with restoration of growth and functionality on thawing. These results present a platform for the development of a new therapeutic system for personalized medicine. PMID:25666845

  12. GATA3 and the T-cell lineage: essential functions before and after T-helper-2-cell differentiation

    Microsoft Academic Search

    Tzong-Shyuan Tai; Sung-Yun Pai; I-Cheng Ho

    2009-01-01

    Many advances in our understanding of the molecules that regulate the development, differentiation and function of T cells have been made over the past few years. One important regulator of T-cell differentiation is the transcription factor GATA-binding protein 3 (GATA3). Although the main function of GATA3 is to act as a master transcription factor for the differentiation of T helper

  13. Breakage-fusion-bridge Cycles and Large Insertions Contribute to the Rapid Evolution of Accessory Chromosomes in a Fungal Pathogen

    PubMed Central

    Croll, Daniel; Zala, Marcello; McDonald, Bruce A.

    2013-01-01

    Chromosomal rearrangements are a major driver of eukaryotic genome evolution, affecting speciation, pathogenicity and cancer progression. Changes in chromosome structure are often initiated by mis-repair of double-strand breaks in the DNA. Mis-repair is particularly likely when telomeres are lost or when dispersed repeats misalign during crossing-over. Fungi carry highly polymorphic chromosomal complements showing substantial variation in chromosome length and number. The mechanisms driving chromosome polymorphism in fungi are poorly understood. We aimed to identify mechanisms of chromosomal rearrangements in the fungal wheat pathogen Zymoseptoria tritici. We combined population genomic resequencing and chromosomal segment PCR assays with electrophoretic karyotyping and resequencing of parents and offspring from experimental crosses to show that this pathogen harbors a highly diverse complement of accessory chromosomes that exhibits strong global geographic differentiation in numbers and lengths of chromosomes. Homologous chromosomes carried highly differentiated gene contents due to numerous insertions and deletions. The largest accessory chromosome recently doubled in length through insertions totaling 380 kb. Based on comparative genomics, we identified the precise breakpoint locations of these insertions. Nondisjunction during meiosis led to chromosome losses in progeny of three different crosses. We showed that a new accessory chromosome emerged in two viable offspring through a fusion between sister chromatids. Such chromosome fusion is likely to initiate a breakage-fusion-bridge (BFB) cycle that can rapidly degenerate chromosomal structure. We suggest that the accessory chromosomes of Z. tritici originated mainly from ancient core chromosomes through a degeneration process that included BFB cycles, nondisjunction and mutational decay of duplicated sequences. The rapidly evolving accessory chromosome complement may serve as a cradle for adaptive evolution in this and other fungal pathogens. PMID:23785303

  14. Using Item Response Theory and Model-Data Fit to Conceptualize Differential Item and Person Functioning for Students with Disabilities

    ERIC Educational Resources Information Center

    Engelhard, George, Jr.

    2009-01-01

    The major purpose of this study is to describe a conceptual framework for examining differential item functioning (DIF) and differential person functioning (DPF) as types of model-data misfit within the context of assessing students with disabilities. Specifically, DIF and DPF can be viewed through the lens of residual analyses. Residual analyses…

  15. A New Method for Assessing the Statistical Significance in the Differential Functioning of Items and Tests (DFIT) Framework

    ERIC Educational Resources Information Center

    Oshima, T. C.; Raju, Nambury S.; Nanda, Alice O.

    2006-01-01

    A new item parameter replication method is proposed for assessing the statistical significance of the noncompensatory differential item functioning (NCDIF) index associated with the differential functioning of items and tests framework. In this new method, a cutoff score for each item is determined by obtaining a (1-alpha ) percentile rank score…

  16. Using a Taxonomy of Differential Step Functioning to Improve the Interpretation of DIF in Polytomous Items: An Illustration

    ERIC Educational Resources Information Center

    Penfield, Randall D.; Alvarez, Karina; Lee, Okhee

    2009-01-01

    The assessment of differential item functioning (DIF) in polytomous items addresses between-group differences in measurement properties at the item level, but typically does not inform which score levels may be involved in the DIF effect. The framework of differential step functioning (DSF) addresses this issue by examining between-group…

  17. Second Argonne theory institute on differentiation of computational approximations of functions.

    SciTech Connect

    Bischof, C.H.; Eberhard, P.; Hovland, P.D.

    1998-10-09

    A Theory Institute on ''Differentiation of Computational Approximations to Functions'' was held at Argonne National Laboratory on May 18--20, 1998. The institute was organized by Christian Bischof and Paul Hovland of the Mathematics and Computer Science Division at Argonne National Laboratory. The Theory Institute brought together 38 researchers from the US, Great Britain, France, and Germany. Mathematicians, computer scientists, physicists, and engineers from diverse disciplines discussed advances in automatic differentiation (AD) theory and software and described benefits from applying AD methods in application areas. These areas include fluid mechanics, structural engineering, optimization, meteorology, and computational mathematics for the solution of ordinary differential equations (ODEs) or differential algebraic equations (DAEs). This meeting was the fourth workshop dedicated to automatic differentiation. Earlier meetings were the 1991 SIAM conference in Breckenridge, Colorado; the first Argonne Theory Institute on computational differentiation in 1993; and the 1996 SIAM conference in Santa Fe, New Mexico. AD methods can be used whenever gradient information or higher-order derivative information must be computed. The problem is defined by a computer program (without gradient information) that is able to compute numerical values of some output variables for a given set of input variables. As a result of applying AD methods to this computer program, a new computer program is generated automatically to compute the derivatives of the output variables with respect to the input variables. This at first glance, astonishing fact can be easily understood by viewing the program from a compiler angle. A complicated computational sequence is split into a sequence of simple operations. Then, to compute the gradients, the chain rule of differentiation is applied successively to this sequence completely automatically. The resultant gradients are accurate up to roundoff errors (which are always present in numerical evaluations).

  18. 46 CFR 98.25-40 - Valves, fittings, and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...inches. Nonferrous materials, such as copper, copper alloys and aluminum alloys, shall not be used in the construction of valves, fittings or accessory equipment. Brazed joints are prohibited. (b) Each tank shall be provided...

  19. 21 CFR 884.4100 - Endoscopic electrocautery and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Sterility Review Guidance 2/12/90 (K-90),” and (iii) “Guidance (‘Guidelines’) for Evaluation of Laproscopic Bipolar and Thermal Coagulators (and Accessories),” (2) International Electrotechnical Commission's IEC 60601-1-AM2...

  20. 21 CFR 884.4100 - Endoscopic electrocautery and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Sterility Review Guidance 2/12/90 (K-90),” and (iii) “Guidance (‘Guidelines’) for Evaluation of Laproscopic Bipolar and Thermal Coagulators (and Accessories),” (2) International Electrotechnical Commission's IEC 60601-1-AM2...

  1. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...6010 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010 Abrasive device and accessories. (a)...

  2. 21 CFR 872.4920 - Dental electrosurgical unit and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Dental electrosurgical unit and accessories...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4920 Dental electrosurgical unit and...

  3. 21 CFR 872.4920 - Dental electrosurgical unit and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Dental electrosurgical unit and accessories...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4920 Dental electrosurgical unit and...

  4. 21 CFR 872.4920 - Dental electrosurgical unit and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Dental electrosurgical unit and accessories...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4920 Dental electrosurgical unit and...

  5. 21 CFR 872.4920 - Dental electrosurgical unit and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Dental electrosurgical unit and accessories...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4920 Dental electrosurgical unit and...

  6. 21 CFR 872.4920 - Dental electrosurgical unit and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Dental electrosurgical unit and accessories...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4920 Dental electrosurgical unit and...

  7. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...6010 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010 Abrasive device and accessories. (a)...

  8. 19 CFR 10.2020 - Accessories, spare parts, or tools.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Panama Trade Promotion Agreement Rules of Origin § 10.2020 Accessories, spare parts, or tools. (a)...

  9. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Abrasive device and accessories. 872.6010 Section 872.6010...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010...

  10. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Abrasive device and accessories. 872.6010 Section 872.6010...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010...

  11. 21 CFR 876.5010 - Biliary catheter and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5010 Biliary catheter and accessories. (a) Identification. A...

  12. 21 CFR 876.5900 - Ostomy pouch and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5900 Ostomy pouch and accessories. (a) Identification. An...

  13. 21 CFR 876.5900 - Ostomy pouch and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5900 Ostomy pouch and accessories. (a) Identification. An...

  14. 21 CFR 876.5900 - Ostomy pouch and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5900 Ostomy pouch and accessories. (a) Identification. An...

  15. 21 CFR 876.4890 - Urological table and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4890 Urological table and accessories. (a) Identification. A...

  16. 21 CFR 876.4890 - Urological table and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4890 Urological table and accessories. (a) Identification. A...

  17. 21 CFR 876.5010 - Biliary catheter and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5010 Biliary catheter and accessories. (a) Identification. A...

  18. 21 CFR 876.5010 - Biliary catheter and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5010 Biliary catheter and accessories. (a) Identification. A...

  19. 21 CFR 876.5540 - Blood access device and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5540 Blood access device and accessories. (a) Identification....

  20. 21 CFR 876.5540 - Blood access device and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5540 Blood access device and accessories. (a) Identification....

  1. 21 CFR 876.5540 - Blood access device and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5540 Blood access device and accessories. (a) Identification....

  2. 21 CFR 876.5540 - Blood access device and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5540 Blood access device and accessories. (a) Identification....

  3. 21 CFR 876.4890 - Urological table and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4890 Urological table and accessories. (a) Identification. A...

  4. 21 CFR 876.4890 - Urological table and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4890 Urological table and accessories. (a) Identification. A...

  5. 21 CFR 876.5900 - Ostomy pouch and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5900 Ostomy pouch and accessories. (a) Identification. An...

  6. 21 CFR 876.5010 - Biliary catheter and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5010 Biliary catheter and accessories. (a) Identification. A...

  7. 21 CFR 876.5900 - Ostomy pouch and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5900 Ostomy pouch and accessories. (a) Identification. An...

  8. 21 CFR 876.5010 - Biliary catheter and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5010 Biliary catheter and accessories. (a) Identification. A...

  9. 21 CFR 876.5540 - Blood access device and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5540 Blood access device and accessories. (a) Identification....

  10. 21 CFR 876.4890 - Urological table and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4890 Urological table and accessories. (a) Identification. A...

  11. 14 CFR 25.1192 - Engine accessory section diaphragm.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...and all portions of the exhaust system must be isolated from the engine accessory compartment by a diaphragm that complies with the firewall requirements of § 25.1191. [Amdt. 25-23, 35 FR 5678, Apr. 8,...

  12. 14 CFR 25.1192 - Engine accessory section diaphragm.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...and all portions of the exhaust system must be isolated from the engine accessory compartment by a diaphragm that complies with the firewall requirements of § 25.1191. [Amdt. 25-23, 35 FR 5678, Apr. 8,...

  13. 21 CFR 884.1600 - Transabdominal amnioscope (fetoscope) and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...system via abdominal entry. The device is used to ascertain fetal abnormalities, to obtain fetal blood samples, or to obtain fetal tissue. This generic type of device may include the following accessories: trocar and cannula, instruments used...

  14. 19 CFR 10.3020 - Accessories, spare parts, or tools.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Colombia Trade Promotion Agreement Rules of Origin § 10.3020 Accessories, spare parts, or tools. (a)...

  15. 19 CFR 10.3020 - Accessories, spare parts, or tools.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Colombia Trade Promotion Agreement Rules of Origin § 10.3020 Accessories, spare parts, or tools. (a)...

  16. 21 CFR 886.1930 - Tonometer and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...flat disk to the cornea). Accessories for the device may include a tonometer calibrator or a tonograph recording system. The device is intended for use in the diagnosis of glaucoma. (b) Classification. Class...

  17. 21 CFR 886.1930 - Tonometer and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...flat disk to the cornea). Accessories for the device may include a tonometer calibrator or a tonograph recording system. The device is intended for use in the diagnosis of glaucoma. (b) Classification. Class...

  18. 21 CFR 886.1930 - Tonometer and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...flat disk to the cornea). Accessories for the device may include a tonometer calibrator or a tonograph recording system. The device is intended for use in the diagnosis of glaucoma. (b) Classification. Class...

  19. Comparative morphology of the accessory olfactory bulb in bats.

    PubMed Central

    Frahm, H D; Bhatnagar, K P

    1980-01-01

    Bouin-perfused brains of 148 bats (76 species, 48 genera, 8 families) were examined in serial sections for the presence of an accessory olfactory bulb. A moderate to well developed AOB was identified in 26 species. However, absence of an AOB in a particular species does not preclude its presence in some other species of that genus. Descriptions and measurements of the AOBs of each species are reported. The unmyelinated vomeronasal nerve enters the bulb medially and posteriorly. The glomeruli, variable in diameter, appear better circumscribed than previously described. Mitral cells often form thick layers, up to five cells deep, which sometimes reach the dorsolateral surface of the bulb formation. Both external and internal plexiform layers are thin. The latter, however is seen only in a few species. The internal granular layer, reaching the ventricular ependyma in some species, is a prominent component of the bulb. The pars dorsalis of the lateral olfactory tract usually courses between the mitral and internal granular layers. The chiropteran AOB does not differ in significant detail from that of insectivores, primates and other mammals. The occurrence of a functional vomeronasal system in the frugivorous, nectarivorous, and sanguivorous Phyllosotomatidae points to a primary functional role of this system in feeding strategy, at least in bats. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 PMID:7400042

  20. Classical torus conformal block, = 2? twisted superpotential and the accessory parameter of Lamé equation

    NASA Astrophysics Data System (ADS)

    Piatek, Marcin

    2014-03-01

    In this work the correspondence between the semiclassical limit of the DOZZ quantum Liouville theory on the torus and the Nekrasov-Shatashvili limit of the = 2? (?-deformed) U(2) super-Yang-Mills theory is used to propose new formulae for the accessory parameter of the Lamé equation. This quantity is in particular crucial for solving the problem of uniformization of the one-punctured torus. The computation of the accessory parameters for torus and sphere is an open longstanding problem which can however be solved if one succeeds to derive an expression for the so-called classical Liouville action. The method of calculation of the latter has been proposed some time ago by Zamolod-chikov brothers. Studying the semiclassical limit of the four-point function of the quantum Liouville theory on the sphere they have derived the classical action for the Riemann sphere with four punctures. In the present work Zamolodchikovs idea is exploited in the case of the Liouville field theory on the torus. It is found that the Lamé accessory parameter is determined by the classical Liouville action on the one-punctured torus or more concretely by the torus classical block evaluated on the saddle point intermediate classical weight. Secondly, as an implication of the aforementioned correspondence it is obtained that the torus accessory parameter is related to the sum of all rescaled column lengths of the so-called "critical" Young diagrams extremizing the instanton "free energy" for the = 2? gauge theory. Finally, it is pointed out that thanks to the known relation the sum over the "critical" column lengths can be expressed in terms of a contour integral in which the integrand is built out of certain special functions.

  1. Radiofrequency catheter ablation of septal accessory atrioventricular pathways.

    PubMed Central

    Xie, B; Heald, S C; Bashir, Y; Camm, A J; Ward, D E

    1994-01-01

    OBJECTIVE--Septal accessory atrioventricular pathways are recognised as being more difficult to ablate than pathways in other locations. This paper describes an experience of 48 consecutive patients with septal accessory pathways who had catheter ablation with radiofrequency current. PATIENTS AND METHODS--There were 28 male and 20 female patients, mean (SD) age 35 (17). 43 patients had a single accessory pathway and 5 patients had multiple accessory pathways. Pre-excitation was present in 37 patients, and 11 patients had concealed accessory pathways. 21 patients had had a previous electrophysiological study. Catheter ablation was undertaken with radiofrequency current delivered by a standard unipolar technique or by delivery of current across the septum (the bipolar technique). RESULTS--The median total procedure time was 167 (83) minutes including a 30-40 minute observation period after the abolition of conduction by the accessory pathway. The median total fluoroscopic time was 56 (30) minutes. 42 (88%) out of 48 patients had successful ablation of the pathway during the first session. In the six patients in whom the procedure failed, five had a midseptal pathway and one had a right anteroseptal pathway. A second attempt at ablation was made in two patients and succeeded in both. In total, 49 accessory pathways were successfully ablated in 44 (92%) out of 48 patients. The bipolar technique was used in 11 patients and succeeded in 10 patients. Standard unipolar current delivery had previously failed in seven of the 11 patients. Complications developed in two patients with a mid septal pathway (one with complete atrioventricular block and the other with a small pericardial effusion). CONCLUSION--Radiofrequency catheter ablation of septal accessory pathways is efficacious and safe. The procedure time can be shortened and success rate can be increased after improvement of the technique--that is, consideration of a bipolar approach for energy delivery in difficult cases. PMID:7946782

  2. Review of accessory tragus with highlights of its associated syndromes.

    PubMed

    Bahrani, Bahar; Khachemoune, Amor

    2014-12-01

    Accessory tragus is a developmental defect involving malformation of part of the external ear. It is a moderately rare congenital condition reported in 1858 by Birkett for the first time. Histological features of accessory tragus include a thin layer of stratum corneum with a rugated epidermis, presence of eccrine glands, and irregular spatial positioning of vellus hair follicles accompanied by sebaceous glands. Accessory tragus is commonly a limited deformity; however, it can be a sign of associated congenital syndromes. It has been shown to be associated with Goldenhar syndrome, Townes-Brocks syndrome, Treacher-Collins syndrome, VACTERL syndrome, and Wolf-Hirschhron syndrome. Surgical excision, the most common form of management of accessory tragus lesions, typically leads to a positive outcome. An extensive search was performed using pubmed.gov, Embase, MedLine, and Googlescholar.com using key words: accessory tragus, congenital malformations of ear, first branchial arch, and embryology. In this paper, we review the clinical and histological presentation, associated syndromes, management, and outcome of accessory tragus. PMID:25266223

  3. On subnormal solutions of periodic non-homogeneous linear differential equations, special functions and special polynomials

    Microsoft Academic Search

    YIK-MAN CHIANG; KIT-WING YU

    2009-01-01

    This paper offers a new and complete description of subnormal solutions of\\u000acertain non-homogeneous second order periodic linear differential equations\\u000afirst studied by Gundersen and Steinbart in 1994. We have established a\\u000apreviously unknown relation that the general solutions (\\\\textit{i.e.}, whether\\u000asubnormal or not) of the DEs can be solved explicitly in terms of classical\\u000aspecial functions, namely the Bessel,

  4. On subnormal solutions of periodic non-homogeneous linear differential equations, special functions and special polynomials

    Microsoft Academic Search

    Y. M. Chiang; K. W. Yu

    2009-01-01

    This paper offers a new and complete description of subnormal solutions of certain non-homogeneous second order periodic linear differential equations first studied by Gundersen and Steinbart in 1994. We have established a previously unknown relation that the general solutions (\\\\textit{i.e.}, whether subnormal or not) of the DEs can be solved explicitly in terms of classical special functions, namely the Bessel,

  5. Geometric interplay between function subspaces and their rings of differential operators

    Microsoft Academic Search

    Rikard Bogvadand; Rolf Källström

    2004-01-01

    We study, in the setting of algebraic varieties, finite-dimensional spaces of functions V that are invariant under a ring D^V of differential operators, and give conditions under which D^V acts irreducibly. We show how this problem, originally formulated in physics (Kamran-Milson-Olver), is related to the study of principal parts bundles and Weierstrass points (Laksov-Thorup), including a detailed study of Taylor

  6. Small functional groups for controlled differentiation of hydrogel-encapsulated human mesenchymal stem cells

    Microsoft Academic Search

    Danielle S. W. Benoit; Michael P. Schwartz; Andrew R. Durney; Kristi S. Anseth

    2008-01-01

    Cell-matrix interactions have critical roles in regeneration, development and disease. The work presented here demonstrates that encapsulated human mesenchymal stem cells (hMSCs) can be induced to differentiate down osteogenic and adipogenic pathways by controlling their three-dimensional environment using tethered small-molecule chemical functional groups. Hydrogels were formed using sufficiently low concentrations of tether molecules to maintain constant physical characteristics, encapsulation of

  7. Small functional groups for controlled differentiation of hydrogel-encapsulated human mesenchymal stem cells

    Microsoft Academic Search

    Danielle S. W. Benoit; Michael P. Schwartz; Andrew R. Durney; Kristi S. Anseth

    2008-01-01

    Cell–matrix interactions have critical roles in regeneration, development and disease. The work presented here demonstrates that encapsulated human mesenchymal stem cells (hMSCs) can be induced to differentiate down osteogenic and adipogenic pathways by controlling their three-dimensional environment using tethered small-molecule chemical functional groups. Hydrogels were formed using sufficiently low concentrations of tether molecules to maintain constant physical characteristics, encapsulation of

  8. Monte carlo evaluation of functionals of solutions of stochastic differential equations. variance reduction and numerical examples

    Microsoft Academic Search

    Wolfgang Wagner

    1988-01-01

    Variance–reducing estimators are derived for functionals of the solution of the general Ito stochastic differential equation. These estimators allow to apply variance reduction techniques known from the Monte Carlo theory. In particular, variance–reducing Euler estimators are constructed as well as variance–reducing unbiased estimators. Numerical examples are given. They show that the variance reduction techniques cause an enormous gain in efficiency,

  9. Describing function based methods for predicting chaos in a class of fractional order differential equations

    Microsoft Academic Search

    Mohammad Saleh Tavazoei; Mohammad Haeri

    2009-01-01

    This paper deals with two different methods for predicting chaotic dynamics in fractional order differential equations. These\\u000a methods, which have been previously proposed for detecting chaos in classical integer order systems, are based on using the\\u000a describing function method. One of these methods is constructed based on Genesio–Tesi conjecture for existence of chaos, and\\u000a another method is introduced based on

  10. Retinoblastoma protein functions as a molecular switch determining white versus brown adipocyte differentiation

    Microsoft Academic Search

    Jacob B. Hansen; Claus Jørgensen; Rasmus K. Petersen; Philip Hallenborg; Rita de Matteis; Hans A. Bøye; Natasa Petrovic; Sven Enerbäck; Jan Nedergaard; Saverio Cinti; Hein Te Riele; Karsten Kristiansen

    2004-01-01

    Adipocyte precursor cells give raise to two major cell populations with different physiological roles: white and brown adipocytes. Here we demonstrate that the retinoblastoma protein (pRB) regulates white vs. brown adipocyte differentiation. Functional inactivation of pRB in wild-type mouse embryo fibroblasts (MEFs) and white preadipocytes by expression of simian virus 40 large T antigen results in the expression of the

  11. Full-length and truncated neurokinin-1 receptor expression and function during monocyte\\/macrophage differentiation

    Microsoft Academic Search

    J.-P. Lai; W. Z. Ho; L. E. Kilpatrick; X. Wang; F. Tuluc; H. M. Korchak; S. D. Douglas

    2006-01-01

    The substance P (SP)-preferring receptor neurokinin-1 receptor (NK-1R) has two forms: a full-length receptor consisting of 407 aa and a truncated receptor consisting of 311 aa. These two receptors differ in the length of the C terminus of NK-1R. We studied the undifferentiated and phorbol myristate acetate (PMA)-differentiated human monocyte\\/macrophage cell line THP-1 to investigate the expression and function of

  12. Transvenous Catheter Ablation of a Posteroseptal Accessory Pathway in a Patient with Coexistent Posteroseptal and Right-Sided Accessory Pathways

    PubMed Central

    Ding-Jiu, Huang; Run-Fen, Chen; Dao-Sheng, Zheng; Ming-Xin, Huang; Morady, Fred

    1988-01-01

    Transvenous catheter ablation techniques have recently been used successfully in blocking posteroseptal accessory pathways in patients with Wolff-Parkinson-White syndrome (WPWS). We report the case of a patient in the People's Republic of China who had WPWS and posteroseptal and right anterolateral accessory pathways, and who had failed to respond to conventional antiarrhythmic drug therapy. The posteroseptal accessory pathway was ablated successfully. During 23 months of follow-up there were no complications; this led us to conclude that this technique can be used to achieve successful long-term ablation of this accessory pathway. This technique obviates the need for drug therapy and direct surgical ablation; it offers, as well, the advantages of shorter hospitalization, lower cost, a much shorter convalescence, and less discomfort to the patient. (Texas Heart Institute Journal 1988;15:61-64) PMID:15227283

  13. From Monocytes to M1/M2 Macrophages: Phenotypical vs. Functional Differentiation

    PubMed Central

    Italiani, Paola; Boraschi, Diana

    2014-01-01

    Studies on monocyte and macrophage biology and differentiation have revealed the pleiotropic activities of these cells. Macrophages are tissue sentinels that maintain tissue integrity by eliminating/repairing damaged cells and matrices. In this M2-like mode, they can also promote tumor growth. Conversely, M1-like macrophages are key effector cells for the elimination of pathogens, virally infected, and cancer cells. Macrophage differentiation from monocytes occurs in the tissue in concomitance with the acquisition of a functional phenotype that depends on microenvironmental signals, thereby accounting for the many and apparently opposed macrophage functions. Many questions arise. When monocytes differentiate into macrophages in a tissue (concomitantly adopting a specific functional program, M1 or M2), do they all die during the inflammatory reaction, or do some of them survive? Do those that survive become quiescent tissue macrophages, able to react as naïve cells to a new challenge? Or, do monocyte-derived tissue macrophages conserve a “memory” of their past inflammatory activation? This review will address some of these important questions under the general framework of the role of monocytes and macrophages in the initiation, development, resolution, and chronicization of inflammation. PMID:25368618

  14. 6,4'-Dihydroxy-7-methoxyflavanone inhibits osteoclast differentiation and function.

    PubMed

    Im, Nam-Kyung; Choi, Je-Yong; Oh, Hyuncheol; Kim, Youn-Chul; Jeong, Gil-Saeng

    2013-01-01

    6,4'-Dihydroxy-7-methoxyflavanone (DMF) is a flavonoid isolated from Heartwood Dalbergia odorifera. It has been known that DMF has antioxidant, anti-inflammatory and neuroprotective effects. DMF, however, the efficacy of bone related diseases has not been reported. In this study, we determined DMF's efficacy on osteoclasts differentiation and function using in vitro bone marrow macrophage osteoclast differentiation culture system. DMF inhibited receptor activators of nuclear factor kappa-B ligand (RANKL) induced osteoclastogenesis dose dependently. In addition, DMF decreased osteoclast function through disruption of actin ring formation and consequently suppression of the pit-forming activity of mature osteoclasts. Mechanistically, DMF inhibited RANKL-induced expression of nuclear factor of activated T-cells, cytoplasmic, calcineurin-dependent 1 (NFATc1) and c-Fos via inhibition of mitogen activated protein kinases (MAPKs) pathway. Collectively, the inhibition of osteoclasts differentiation and function by DMF suggests that DMF can be a potential therapeutic molecule for osteoclastogenic bone diseases such osteoporosis, rheumatoid arthritis and periodontal diseases. PMID:23420617

  15. Spatial congregation of STAT binding directs selective nuclear architecture during T-cell functional differentiation

    PubMed Central

    Hakim, Ofir; Sung, Myong-Hee; Nakayamada, Shingo; Voss, Ty C.; Baek, Songjoon; Hager, Gordon L.

    2013-01-01

    Higher-order genome organization shows tissue-specific patterns. However, functional relevance and the mechanisms shaping the genome architecture are poorly understood. Here we report a profound shift from promiscuous to highly selective genome organization that accompanies the effector lineage choice of differentiating T cells. As multipotent naive cells receive antigenic signals and commit to a T helper (Th) pathway, the genome-wide contacts of a lineage-specific cytokine locus are preferentially enriched for functionally relevant genes. Despite the establishment of divergent interactomes and global reprogramming of transcription in Th1 versus Th2, the overall expression status of the contact genes is surprisingly similar between the two lineages. Importantly, during differentiation, the genomic contacts are retained and strengthened precisely at DNA binding sites of the specific lineage-determining STAT transcription factor. In cells from the specific STAT knock-out mouse, the signature cytokine locus is unable to shed the promiscuous contacts established in the naive T cells, indicating the importance of genomic STAT binding. Altogether, the global aggregation of STAT binding loci from genic and nongenic regions highlights a new role for differentiation-promoting transcription factors in direct specification of higher-order nuclear architecture through interacting with regulatory regions. Such subnuclear environments have significant implications for efficient functioning of the mature effector lymphocytes. PMID:23212947

  16. Isolating D" structure using ScS-S differential response functions

    NASA Astrophysics Data System (ADS)

    Fisher, J.; Wysession, M.

    2003-04-01

    Differential seismic phase studies are commonly used for isolating anomalies in a particular region of the Earth. We present a method called differential response functions, DRFs, which not only isolate a travel time or attenuation measurement, but also isolate the differential response of a region. While this technique may be used with any number of phases, we demonstrate its usefulness using ScS and S phases to examine D" seismic structure. The differential response function is simply the transfer function between the ScS and S phases. By deconvolving the S phase from the ScS phase we remove source, receiver, and upper mantle contributions to the ScS phase. The remaining signal is a function of the lower mantle response to the S and ScS. The DRF contains information regarding quality factor, velocity contrasts at interfaces, interface depths, and velocities. Variations in the D" quality factor, Q?(D"), and shear velocity, V?, produce significant changes to synthetic DRFs. Low velocity layers within D" produce DRFs with delayed phase corresponding to differential travel-time measurements. Attenuated ScS phases have measured attenuation values, t*, corresponding to the difference between S and ScS attenuation, ? t*(ScS-S). The shape of the DRF reflects ScS interaction with large interfaces, such as the entrance into and exit from a low velocity layer. The relative amplitude of the ScS to S phase is also maintained, allowing for improved estimates of velocity contrast at an interface. The major boon of DRF's is that they allow direct modeling of an isolated region within the earth such as D". Additional advantages of the DRF (over standard differential anomaly measurement techniques) include their ease of stacking, their dependence upon interfaces, and their simultaneous isolation of both elastic and anelastic measurements alike. Variations in the observed ScS-S DRF shape from region to region may indicate large differences between lower mantle structures. Preliminary comparison between synthetic and observed ScS-S DRFs indicates that the lower mantle varies in both V? and Q?(D"). Additionally, differences between SH and SV component DRF's may indicate anisotropic lower mantle structures.

  17. Differentially disrupted functional connectivity in posteromedial cortical subregions in Alzheimer's disease.

    PubMed

    Xia, Mingrui; Wang, Zhiqun; Dai, Zhengjia; Liang, Xia; Song, Haiqing; Shu, Ni; Li, Kuncheng; He, Yong

    2014-01-01

    Neuroimaging studies have demonstrated that patients with Alzheimer's disease (AD) have remarkable focal grey matter loss and hypometabolism in the posteromedial cortex (PMC), which is composed of the precuneus and posterior cingulate cortex, suggesting an important association of the PMC with AD pathophysiology. Studies have also shown that the PMC is a structurally and functionally heterogeneous structure containing various subregions with distinct connectivity profiles. However, whether these PMC subregions show differentially disrupted connectivity patterns in AD remains largely unknown. Here, we addressed this issue by collecting resting-state functional MRI data from 32 AD patients and 38 healthy controls. We automatically identified the PMC subregions using a graph-based module detection algorithm and then mapped the whole-brain functional connectivity pattern of each subregion. The functional connectivity analysis was followed by a hierarchical clustering analysis to classify each subregion. Three distinct spatial connectivity patterns were observed across the PMC subregions: the anterior dorsal zone was functionally connected with the sensorimotor cortex; the posterior dorsal zone was functionally connected with the frontoparietal cortex; and the central and ventral zones were functionally connected with the default-mode regions. Group comparison analysis revealed that all three functional systems were significantly disrupted in the AD patients compared to the controls and these disruptions were positively correlated with the patients' cognitive performance. Collectively, we showed that the subregions of the PMC exhibit differentially disrupted neuronal circuitry in AD patients, which provides new insight into the functional neuroanatomy of the human PMC and the alterations that may be relevant to disease. PMID:24217277

  18. Cellular Trafficking of Phospholamban and Formation of Functional Sarcoplasmic Reticulum During Myocyte DIfferentiation

    SciTech Connect

    Stenoien, David L.; Knyushko, Tatyana V.; Londono, Monica P.; Opresko, Lee; Mayer, M. Uljana; Brady, Scott T.; Squier, Thomas C.; Bigelow, Diana J.

    2007-06-01

    The sarco/endoplasmic reticulum Ca-ATPase (SERCA) family members are transmembrane proteins that play an essential role in regulating intracellular calcium levels. Phospholamban (PLB), a 52 amino acid phosphoprotein, regulates SERCA activity in adult heart and skeletal muscle. Using the C2C12 myocyte cell line, we find endogenous PLB constitutively expressed in both myoblasts and myotubes, whereas SERCA expression coincides with activation of the differentiation program. PLB has a punctuate distribution in myoblasts changing to a reticular distribution in myotubes where it colocalizes with SERCAs. To examine the distribution and dynamics of PLB and SERCA, we expressed fluorescent fusion proteins (GFP, CFP, and YFP) of PLB and SERCA in myoblasts. Coexpressed PLB and SERCA localize to distinct cellular compartments in myoblasts but begin to colocalize as cells differentiate. Fluorescence Recovery After Photobleaching (FRAP) studies show different recovery patterns for each protein in myoblasts confirming their localization to distinct compartments. To extend these studies, we created stable cell lines expressing O6-alkylguanine-DNA alkyltransferase (AGT) fusions with PLB or SERCA to track their localization as myocytes differentiate. These experiments demonstrate that PLB localizes to punctate vesicles in myoblasts and adopts a reticular distribution that coincides with SERCA distribution after differentiation. Colocalization experiments indicate that a subset of PLB in myoblasts colocalizes with endosomes, Golgi, and the plasma membrane however PLB also localizes to other, as yet unidentified vesicles. Our results indicate that differentiation plays a critical role in regulating PLB distribution to ensure its colocalization within the same cellular compartment as SERCA in differentiated cells. The presence and altered distribution of PLB in undifferentiated myoblasts raises the possibility that this protein has additional functions distinct from SERCA regulation.

  19. Boundary value problem of Schottky on a closed Riemann surface in spaces of generalized functions and differentials

    Microsoft Academic Search

    S. A. Yatsenko

    1971-01-01

    Definition 1. Identify every linear continuous functional defined on the fundamental spaces S(dh) and S(g) with the generalized function f and the generalized differential d~ respectively: [:dh(t)~.(~, dh(t)), d(p:g(t)=~,(d% g(t)). Let S~dh) and S~g) be the spaces of generalized functions and differentials, respectively. We shall solve the Schottky problem in the fundamental spaces according to the general scheme [3] of

  20. Differential diagnosis of adults with ADHD: the role of executive function and self-regulation.

    PubMed

    Barkley, Russell A

    2010-07-01

    Adult ADHD is conceptualized as a disorder of age-inappropriate behavior that occurs because of maldevelopment of 2 related neuropsychological domains. The neuropsychological symptoms seen in adults with ADHD may be explained by deficits in executive function, which can be broadly defined as a set of neurocognitive processes that allow for the organization of behavior across time so as to attain future goals. Executive function is comprised of 2 broad domains: inhibition and metacognition. Inhibition encompasses the ability to inhibit motor, verbal, cognitive, and emotional activities. In turn, deficits in inhibition contribute to deficits in the development of 4 aspects of executive function in the domain of metacognition, which include nonverbal working memory, verbal working memory, planning and problem-solving, and emotional self-regulation. Understanding the ways in which deficits in executive function contribute to the symptoms of ADHD can help in differentiating ADHD from disorders that share similar characteristics. PMID:20667287

  1. Age-related Differential Item Functioning for the Patient-Reported Outcomes Information System (PROMIS®) Physical Functioning Items

    PubMed Central

    Paz, Sylvia H; Spritzer, Karen L; Morales, Leo S; Hays, Ron D

    2013-01-01

    Purpose To evaluate the equivalence of the PROMIS® wave 1 physical functioning item bank, by age (50 years or older versus 18-49). Materials and methods A total of 114 physical functioning items with 5 response choices were administered to English- (n=1504) and Spanish-language (n=640) adults. Item frequencies, means and standard deviations, item-scale correlations, and internal consistency reliability were estimated. Differential Item Functioning (DIF) by age was evaluated. Results Thirty of the 114 items were fagged for DIF based on an R-squared of 0.02 or above criterion. The expected total score was higher for those respondents who were 18-49 than those who were 50 or older. Conclusions Those who were 50 years or older versus 18-49 years old with the same level of physical functioning responded differently to 30 of the 114 items in the PROMIS® physical functioning item bank. This study yields essential information about the equivalence of the physical functioning items in older versus younger individuals. PMID:24052925

  2. The core and accessory genomes of Burkholderia pseudomallei: implications for human melioidosis.

    PubMed

    Sim, Siew Hoon; Yu, Yiting; Lin, Chi Ho; Karuturi, R Krishna M; Wuthiekanun, Vanaporn; Tuanyok, Apichai; Chua, Hui Hoon; Ong, Catherine; Paramalingam, Sivalingam Suppiah; Tan, Gladys; Tang, Lynn; Lau, Gary; Ooi, Eng Eong; Woods, Donald; Feil, Edward; Peacock, Sharon J; Tan, Patrick

    2008-10-01

    Natural isolates of Burkholderia pseudomallei (Bp), the causative agent of melioidosis, can exhibit significant ecological flexibility that is likely reflective of a dynamic genome. Using whole-genome Bp microarrays, we examined patterns of gene presence and absence across 94 South East Asian strains isolated from a variety of clinical, environmental, or animal sources. 86% of the Bp K96243 reference genome was common to all the strains representing the Bp "core genome", comprising genes largely involved in essential functions (eg amino acid metabolism, protein translation). In contrast, 14% of the K96243 genome was variably present across the isolates. This Bp accessory genome encompassed multiple genomic islands (GIs), paralogous genes, and insertions/deletions, including three distinct lipopolysaccharide (LPS)-related gene clusters. Strikingly, strains recovered from cases of human melioidosis clustered on a tree based on accessory gene content, and were significantly more likely to harbor certain GIs compared to animal and environmental isolates. Consistent with the inference that the GIs may contribute to pathogenesis, experimental mutation of BPSS2053, a GI gene, reduced microbial adherence to human epithelial cells. Our results suggest that the Bp accessory genome is likely to play an important role in microbial adaptation and virulence. PMID:18927621

  3. The Core and Accessory Genomes of Burkholderia pseudomallei: Implications for Human Melioidosis

    PubMed Central

    Lin, Chi Ho; Karuturi, R. Krishna M.; Wuthiekanun, Vanaporn; Tuanyok, Apichai; Chua, Hui Hoon; Ong, Catherine; Paramalingam, Sivalingam Suppiah; Tan, Gladys; Tang, Lynn; Lau, Gary; Ooi, Eng Eong; Woods, Donald; Feil, Edward; Peacock, Sharon J.; Tan, Patrick

    2008-01-01

    Natural isolates of Burkholderia pseudomallei (Bp), the causative agent of melioidosis, can exhibit significant ecological flexibility that is likely reflective of a dynamic genome. Using whole-genome Bp microarrays, we examined patterns of gene presence and absence across 94 South East Asian strains isolated from a variety of clinical, environmental, or animal sources. 86% of the Bp K96243 reference genome was common to all the strains representing the Bp “core genome”, comprising genes largely involved in essential functions (eg amino acid metabolism, protein translation). In contrast, 14% of the K96243 genome was variably present across the isolates. This Bp accessory genome encompassed multiple genomic islands (GIs), paralogous genes, and insertions/deletions, including three distinct lipopolysaccharide (LPS)-related gene clusters. Strikingly, strains recovered from cases of human melioidosis clustered on a tree based on accessory gene content, and were significantly more likely to harbor certain GIs compared to animal and environmental isolates. Consistent with the inference that the GIs may contribute to pathogenesis, experimental mutation of BPSS2053, a GI gene, reduced microbial adherence to human epithelial cells. Our results suggest that the Bp accessory genome is likely to play an important role in microbial adaptation and virulence. PMID:18927621

  4. Female gametophytic cell specification and seed development require the function of the putative Arabidopsis INCENP ortholog WYRD.

    PubMed

    Kirioukhova, Olga; Johnston, Amal J; Kleen, Daniela; Kägi, Christina; Baskar, Ramamurthy; Moore, James M; Bäumlein, Helmut; Gross-Hardt, Rita; Grossniklaus, Ueli

    2011-08-01

    In plants, gametes, along with accessory cells, are formed by the haploid gametophytes through a series of mitotic divisions, cell specification and differentiation events. How the cells in the female gametophyte of flowering plants differentiate into gametes (the egg and central cell) and accessory cells remains largely unknown. In a screen for mutations that affect egg cell differentiation in Arabidopsis, we identified the wyrd (wyr) mutant, which produces additional egg cells at the expense of the accessory synergids. WYR not only restricts gametic fate in the egg apparatus, but is also necessary for central cell differentiation. In addition, wyr mutants impair mitotic divisions in the male gametophyte and endosperm, and have a parental effect on embryo cytokinesis, consistent with a function of WYR in cell cycle regulation. WYR is upregulated in gametic cells and encodes a putative plant ortholog of the inner centromere protein (INCENP), which is implicated in the control of chromosome segregation and cytokinesis in yeast and animals. Our data reveal a novel developmental function of the conserved cell cycle-associated INCENP protein in plant reproduction, in particular in the regulation of egg and central cell fate and differentiation. PMID:21752930

  5. Functional association of the morphogenic factors with the clusterin for the pancreatic beta-cell differentiation.

    PubMed

    Kim, So-Yoon; Lee, Song; Min, Bon-Hong; Park, In-Sun

    2007-09-01

    Several differentiation or morphogenic factors have known to be involved in the developmental process of endocrine pancreas. However, mechanism of action and functional relation of these molecules are not well elucidated particularly in beta-cell formation from adult pancreatic stem cells. We hypothesized that adult pancreatic stem cells could be activated by the functional resumption of the morphogenic factors that were involved in embryonic development of pancreas in the duct system under the specific conditions such as tissue injuries. Besides the well-established genes including Pdx-1 and Ngn-3, we propose the nestin and clusterin as the new morphogenic factors for beta-cell neogenesis and their functional associations. We found extensive in vivo formation of ductules showing a higher replicating ability following the experimental tissue injury. These neogenic ductules were lined with low epithelial cells positive for the nestin, which has been known as neuronal stem cell marker. In in vitro culture, the nestin-rich epithelial cells of the neogenic ductules also displayed extensive self-replication leading to monolayer of epithelial cell explants and transformed into the insulin secreting beta cells as well as duct cells. Thus, we depicted them as nestin-positive duct stem (NPDS) cells. We found a neogenesis specific protein 'clusterin' in the regenerating pancreatic tissues with concomitant increase of Pdx-1 and Ngn-3 expression. The protein is expressed predominantly in the neogenic pancreas undergoing differentiation. In vitro over-expression of the clusterin gene strongly induces beta-cell transformation from neogenic ductal cells. Insulin expression, both insulin mRNA and peptide levels, was increased and showed glucose dependent manner by ectopic expression of clusterin upon the culture of neogenic ductules when compared to the mock-transfected control, implying that the duct cells transformed functional beta cells. We observed that clusterin over-expression led to up-regulation of Pdx-1 and Ngn-3, and clusterin levels were increased upon the transfection of cDNAs of Pdx-1 or Ngn-3, suggesting a close functional association of these morphogenic factors. In conclusion, we suggest that adult pancreatic stem cells can be recapitulated for neogenesis of insulin secreting beta cells not only by reactivation Pdx-1 and Ngn-3, the classical differentiation factors for pancreas development, but also by the intervention of new morphogenic factors including nestin and clusterin. In particular, by modulation of Pdx-1 and Ngn-3, clusterin induces remarkable differentiation of the functional beta cells secreting insulin in response to glucose stimulation. PMID:17512083

  6. HIF-2? downregulation in the absence of functional VHL is not sufficient for renal cell differentiation

    PubMed Central

    Hughes, Michael D; Kapllani, Erilda; Alexander, Ashlynn E; Burk, Robert D; Schoenfeld, Alan R

    2007-01-01

    Background Mutational inactivation of the von Hippel-Lindau (VHL) tumor suppressor gene has been linked to hereditary as well as sporadic clear cell renal carcinomas. The product of the VHL gene, pVHL, acts to target hypoxia-inducible factor alpha (HIF-?) subunits for ubiquitination and subsequent degradation. Using an RNA interference approach to lower levels of HIF-2? in two different renal cell lines that lack functional pVHL, we have tested the contribution of HIF-2? toward cellular pVHL activities. Results Knockdown of HIF-2? resulted in cell cycle arrest of renal cells that were grown on collagen I, indicating that this pVHL function is dependent on HIF-2? regulation. However, cellular morphological changes and downregulation of integrins ?5 and ?1, which were seen upon pVHL replacement, were not faithfully phenocopied by HIF-2? reduction. Moreover, fibronectin deposition and expression of renal cell differentiation markers were observed in cells containing replaced pVHL, but not in HIF-2? knockdown cells, indicating that these pVHL functions may occur independently of HIF-2? downregulation. Conclusion These results indicate that HIF-2? regulation is not sufficient for pVHL-induced renal cell differentiation. We hypothesize that in addition to HIF-2? dysregulation, abrogation of additional pVHL functions is required for the initiation of renal carcinogenesis. PMID:17598890

  7. A note on order of convergence of numerical method for neutral stochastic functional differential equations

    NASA Astrophysics Data System (ADS)

    Jiang, Feng; Shen, Yi; Wu, Fuke

    2012-03-01

    In this paper, we study the order of convergence of the Euler-Maruyama (EM) method for neutral stochastic functional differential equations (NSFDEs). Under the global Lipschitz condition, we show that the pth moment convergence of the EM numerical solutions for NSFDEs has order p/2 - 1/ l for any p ? 2 and any integer l > 1. Moreover, we show the rate of the mean-square convergence of EM method under the local Lipschitz condition is 1 - ?/2 for any ? ? (0, 1), provided the local Lipschitz constants of the coefficients, valid on balls of radius j, are supposed not to grow faster than log j. This is significantly different from the case of stochastic differential equations where the order is 1/2.

  8. Mitochondrial biogenesis and energy production in differentiating murine stem cells: a functional metabolic study.

    PubMed

    Han, Sungwon; Auger, Christopher; Thomas, Sean C; Beites, Crestina L; Appanna, Vasu D

    2014-02-01

    The significance of metabolic networks in guiding the fate of the stem cell differentiation is only beginning to emerge. Oxidative metabolism has been suggested to play a major role during this process. Therefore, it is critical to understand the underlying mechanisms of metabolic alterations occurring in stem cells to manipulate the ultimate outcome of these pluripotent cells. Here, using P19 murine embryonal carcinoma cells as a model system, the role of mitochondrial biogenesis and the modulation of metabolic networks during dimethyl sulfoxide (DMSO)-induced differentiation are revealed. Blue native polyacrylamide gel electrophoresis (BN-PAGE) technology aided in profiling key enzymes, such as hexokinase (HK) [EC 2.7.1.1], glucose-6-phosphate isomerase (GPI) [EC 5.3.1.9], pyruvate kinase (PK) [EC 2.7.1.40], Complex I [EC 1.6.5.3], and Complex IV [EC 1.9.3.1], that are involved in the energy budget of the differentiated cells. Mitochondrial adenosine triphosphate (ATP) production was shown to be increased in DMSO-treated cells upon exposure to the tricarboxylic acid (TCA) cycle substrates, such as succinate and malate. The increased mitochondrial activity and biogenesis were further confirmed by immunofluorescence microscopy. Collectively, the results indicate that oxidative energy metabolism and mitochondrial biogenesis were sharply upregulated in DMSO-differentiated P19 cells. This functional metabolic and proteomic study provides further evidence that modulation of mitochondrial energy metabolism is a pivotal component of the cellular differentiation process and may dictate the final destiny of stem cells. PMID:24350892

  9. Menstrual blood-derived mesenchymal stem cells differentiate into functional hepatocyte-like cells*

    PubMed Central

    Mou, Xiao-zhou; Lin, Jian; Chen, Jin-yang; Li, Yi-fei; Wu, Xiao-xing; Xiang, Bing-yu; Li, Cai-yun; Ma, Ju-ming; Xiang, Charlie

    2013-01-01

    Orthotopic liver transplantation (OLT) is the only proven effective treatment for both end-stage and metabolic liver diseases. Hepatocyte transplantation is a promising alternative for OLT, but the lack of available donor livers has hampered its clinical application. Hepatocyte-like cells (HLCs) differentiated from many multi-potential stem cells can help repair damaged liver tissue. Yet almost suitable cells currently identified for human use are difficult to harvest and involve invasive procedures. Recently, a novel mesenchymal stem cell derived from human menstrual blood (MenSC) has been discovered and obtained easily and repeatedly. In this study, we examined whether the MenSCs are able to differentiate into functional HLCs in vitro. After three weeks of incubation in hepatogenic differentiation medium containing hepatocyte growth factor (HGF), fibroblast growth factor-4 (FGF-4), and oncostain M (OSM), cuboidal HLCs were observed, and cells also expressed hepatocyte-specific marker genes including albumin (ALB), ?-fetoprotein (AFP), cytokeratin 18/19 (CK18/19), and cytochrome P450 1A1/3A4 (CYP1A1/3A4). Differentiated cells further demonstrated in vitro mature hepatocyte functions such as urea synthesis, glycogen storage, and indocyanine green (ICG) uptake. After intrasplenic transplantation into mice with 2/3 partial hepatectomy, the MenSC-derived HLCs were detected in recipient livers and expressed human ALB protein. We also showed that MenSC-derived HLC transplantation could restore the serum ALB level and significantly suppressed transaminase activity of liver injury animals. In conclusion, MenSCs may serve as an ideal, easily accessible source of material for tissue engineering and cell therapy of liver tissues. PMID:24190442

  10. Main Goal Properties of Infinite Series Workshop #10 Uniform Convergence and Differentiability Series of Functions P Math 311: Advanced Calculus

    E-print Network

    Vasconcelos, Wolmer

    Main Goal Properties of Infinite Series Workshop #10 Uniform Convergence and Differentiability Vasconcelos Set 6 Advanced Calculus #12;Main Goal Properties of Infinite Series Workshop #10 Uniform Convergence and Differentiability Series of Functions P Outline 1 Main Goal 2 Properties of Infinite Series 3

  11. Symbolic computation of some new nonlinear partial differential equations of nanobiosciences using modified extended tanh-function method

    Microsoft Academic Search

    Dalibor L. Sekuli?; Miljko V. Satari?; Miloš B. Živanov

    2011-01-01

    By means of computerized symbolic computation and a modified extended tanh-function method the multiple travelling wave solutions of nonlinear partial differential equations is presented and implemented in a computer algebraic system. Applying this method, we consider some of nonlinear partial differential equations of special interest in nanobiosciences and biophysics namely, the transmission line models of microtubules for nano-ionic currents. The

  12. Differential Impact of Parent Functioning on Infant Social Emotional Functioning During the Transition to Parenthood

    E-print Network

    Carhart, Kathryn Patricia

    2012-07-16

    the ability to react pro-socially to a friend who is upset (Denham, 1998). The development of these competencies in early childhood can impact functioning in later childhood and adolescence. SED has even been deemed the ?foundation? of many areas of child... and adolescent adjustment (Deater-Deckard, 2008). SED in Infants and Toddlers The first several years of a child?s life are important in the development of social and emotional capacities. Within the first several days following birth, infants demonstrate...

  13. Incorporation of functionalized gold nanoparticles into nanofibers for enhanced attachment and differentiation of mammalian cells

    PubMed Central

    2012-01-01

    Background Electrospun nanofibers have been widely used as substrata for mammalian cell culture owing to their structural similarity to natural extracellular matrices. Structurally consistent electrospun nanofibers can be produced with synthetic polymers but require chemical modification to graft cell-adhesive molecules to make the nanofibers functional. Development of a facile method of grafting functional molecules on the nanofibers will contribute to the production of diverse cell type-specific nanofiber substrata. Results Small molecules, peptides, and functionalized gold nanoparticles were successfully incorporated with polymethylglutarimide (PMGI) nanofibers through electrospinning. The PMGI nanofibers functionalized by the grafted AuNPs, which were labeled with cell-adhesive peptides, enhanced HeLa cell attachment and potentiated cardiomyocyte differentiation of human pluripotent stem cells. Conclusions PMGI nanofibers can be functionalized simply by co-electrospinning with the grafting materials. In addition, grafting functionalized AuNPs enable high-density localization of the cell-adhesive peptides on the nanofiber. The results of the present study suggest that more cell type-specific synthetic substrata can be fabricated with molecule-doped nanofibers, in which diverse functional molecules are grafted alone or in combination with other molecules at different concentrations. PMID:22686683

  14. Function of the c-Myc antagonist Mad1 during a molecular switch from proliferation to differentiation.

    PubMed Central

    Cultraro, C M; Bino, T; Segal, S

    1997-01-01

    Mad-Max heterodimers have been shown to antagonize Myc transforming activity by a mechanism requiring multiple protein-protein and protein-DNA interactions. However, the mechanism by which Mad functions in differentiation is unknown. Here, we present evidence that Mad functions by an active repression mechanism to antagonize the growth-promoting function(s) of Myc and bring about a transition from cellular proliferation to differentiation. We demonstrate that exogenously expressed c-Myc blocks inducer-mediated differentiation of murine erythroleukemia cells without disrupting the induction of endogenous Mad; rather, high levels of c-Myc prevent a heterocomplex switch from growth-promoting Myc-Max to growth-inhibitory Mad-Max. Cotransfection of a constitutive c-myc with a zinc-inducible mad1 results in clones expressing both genes, whereby a switch from proliferation to differentiation can be modulated. Whereas cells grown in N'N'-hexamethylene bisacetamide in the absence of zinc fail to differentiate, addition of zinc up-regulates Mad expression by severalfold and differentiation proceeds normally. Coimmunoprecipitation analysis reveals that Mad-Max complexes are in excess of Myc-Max in these cotransfectants. Moreover, we show that the Sin-binding, basic region, and leucine zipper motifs are required for Mad to function during a molecular switch from proliferation to differentiation. PMID:9111304

  15. Differential Abundance of Microbial Functional Groups along the Elevation Gradient from the Coast to the Luquillo Mountains

    EPA Science Inventory

    Microbial communities respond to multiple abiotic and biotic factors that change along elevation gradients. We compare changes in microbial community composition in soil and review previous research on differential abundance of microbial functional groups along an elevation gradi...

  16. Interleukin-21 suppresses the differentiation and functions of T helper 2 cells.

    PubMed

    Lin, Pin-Yi; Jen, Hsiao-Yu; Chiang, Bor-Luen; Sheu, Fuu; Chuang, Ya-Hui

    2015-04-01

    T helper type 2 (Th2) cells, which produce interleukin-4 (IL-4), IL-5 and IL-13, control immunity to all forms of allergic inflammatory responses. Interleukin-21 (IL-21) reduces allergic symptoms in murine models and inhibits IL-4-induced IgE secretion by B cells. However, whether or not IL-21 directly affects Th2 cells, which leads to reduced allergic symptoms, is unclear. In this study, we investigated the effects of IL-21 on the differentiation and effector functions of Th2 cells. We found that IL-21 reduced the number of differentiated Th2 cells and these Th2 cells showed a diminished Th2 cytokine production. Interleukin-21 suppressed Th2 cytokine production of already polarized Th2 cells by down-regulation of transcription factor GATA-3. It also induced apoptosis of Th2 cells with decreased anti-apoptotic factor Bcl-2. Intranasal administration of IL-21 at the beginning of ovalbumin (OVA) sensitization or before OVA challenge decreased Th2 cytokines in the bronchoalveolar lavage fluid of OVA/alum-immunized allergic mice. In addition, the inhibitory effects of IL-21 on Th2 effector functions can also be found in allergic patients. Our results demonstrate that IL-21 suppresses the development of Th2 cells and functions of polarized Th2 cells. Hence, the administration of IL-21 may be considered for use as a preventive and therapeutic approach when dealing with Th2-mediated allergic diseases. PMID:25351608

  17. A special class of Painlevé differential systems that generalize the elliptic functions a)

    NASA Astrophysics Data System (ADS)

    Gaffet, B.

    2015-04-01

    The elliptic functions of order 2 may be viewed as the ratios Z2/Z1 of the solutions of a differential system of the general form: Zi 3 / 8 /d 2 (Z j / Z i) d u 2 = Z j R i i - Z i R ij (i ? j , i , j = 1 , … , n), where n = 2, u is the independent variable, and the Rij are the homogeneous quadratic functions of the n variables Zi. The general solution of systems of this form automatically consists, for all n, of purely meromorphic functions. For arbitrary values of n, the system consists of n (n - 1) equations for (n - 1) inhomogeneous variables Zi/Z1, and the question arises as to whether there may exist systems of the above form, with n > 2, which are equivalent to a non-over-determined differential system of p equations, when n-p-1 appropriately chosen algebraic constraints are imposed on the dependent variables. In the present work, we show that such systems do exist, with n = 4 and n = 8, and are in fact special cases of the Dyson model (1968) of a spinning cloud of ellipsoidal shape, expanding adiabatically into a vacuum.

  18. A Monte Carlo Examination of the Sensitivity of the Differential Functioning of Items and Tests Framework for Tests of Measurement Invariance with Likert Data

    ERIC Educational Resources Information Center

    Meade, Adam W.; Lautenschlager, Gary J.; Johnson, Emily C.

    2007-01-01

    This article highlights issues associated with the use of the differential functioning of items and tests (DFIT) methodology for assessing measurement invariance (or differential functioning) with Likert-type data. Monte Carlo analyses indicate relatively low sensitivity of the DFIT methodology for identifying differential item functioning (DIF)…

  19. Notch-regulated periphery B cell differentiation involves suppression of E protein function

    PubMed Central

    Zhang, Ping; Zhao, Ying; Sun, Xiao-Hong

    2013-01-01

    Notch signaling pathway plays important roles in promoting the generation of marginal zone (MZ) B cells at the expense of follicular (FO) B cells during periphery B cell maturation, but the underlying molecular mechanisms are not well understood. We hypothesize that Notch favors the generation of MZ B cells by down-regulating E protein activity. Here, we demonstrated that expression of Id2 and ankyrin-repeat SOCS box-containing protein 2 (Asb2) was elevated in MZ B cells and by Notch signaling. Id2 inhibits the DNA binding activity of E proteins whereas Asb2 facilitates E protein ubiquitination. Next, we examined the phenotypes of splenic B cells in mice expressing constitutively active Notch1 and/or two gain-of-function mutants of E proteins that counteract Id2-mediated inhibition or Notch-induced degradation. We found that up-regulation of E proteins promoted the formation of FO B cells while it suppressed the maturation of MZ B cells. In contrast, excessive amounts of Notch1 stimulated the differentiation of MZ B cells and inhibited the production of FO B cells. More interestingly, the effects of Notch1 were reversed by gain of E protein function. Furthermore, high levels of Bcl-6 expression in FO B cells was shown to be diminished by Notch signaling and restored by E proteins. In addition, E proteins facilitated and Notch hindered the differentiation of transitional B cells. Taken together, it appears that Notch regulates peripheral B cell differentiation, at least in part, through opposing E protein function. PMID:23752615

  20. Either Main or Accessory Olfactory System Signaling Can Mediate the Rewarding Effects of Estrous Female Chemosignals in Sexually Naïve Male Mice

    PubMed Central

    Korzan, Wayne J.; Freamat, Mihael; Johnson, Adam G.; Cherry, James A.; Baum, Michael J.

    2014-01-01

    A long-held view has been that interest of male mice in female body odors reflects an activation of reward circuits in the male brain following their detection by the vomeronasal organ (VNO) and processing via the accessory olfactory system. We found that adult, sexually naïve male mice acquired a conditioned place preference (CPP) after repeatedly receiving estrous female urine on the nose and being placed in an initially non-preferred chamber with soiled estrous bedding on the floor. CPP was not acquired in control mice that received saline on the nose before being placed in a non-preferred chamber with clean bedding. Robust acquisition of a CPP using estrous female odors as the reward persisted in separate groups of mice in which VNO-accessory olfactory function was disrupted by bilateral lesioning of the accessory olfactory bulb (AOB) or in which main olfactory function was disrupted by zinc sulfate lesions of the main olfactory epithelium (MOE). By contrast, no CPP was acquired for estrous odors in males that received combined AOB and MOE lesions. Either the main or the accessory olfactory system suffices to mediate the rewarding effects of estrous female odors in the male mouse, even in the absence of prior mating experience. The main olfactory system is part of the circuitry that responds to chemosignals involved in motivated behavior, a role that may be particularly important for humans which lack a functional accessory olfactory system. PMID:23978150

  1. Mutational Signatures of De-Differentiation in Functional Non-Coding Regions of Melanoma Genomes

    PubMed Central

    Parker, Stephen C. J.; Gartner, Jared; Cardenas-Navia, Isabel; Wei, Xiaomu; Ozel Abaan, Hatice; Ajay, Subramanian S.; Hansen, Nancy F.; Song, Lingyun; Bhanot, Umesh K.; Killian, J. Keith; Gindin, Yevgeniy; Walker, Robert L.; Meltzer, Paul S.; Mullikin, James C.; Furey, Terrence S.; Crawford, Gregory E.; Rosenberg, Steven A.; Samuels, Yardena; Margulies, Elliott H.

    2012-01-01

    Much emphasis has been placed on the identification, functional characterization, and therapeutic potential of somatic variants in tumor genomes. However, the majority of somatic variants lie outside coding regions and their role in cancer progression remains to be determined. In order to establish a system to test the functional importance of non-coding somatic variants in cancer, we created a low-passage cell culture of a metastatic melanoma tumor sample. As a foundation for interpreting functional assays, we performed whole-genome sequencing and analysis of this cell culture, the metastatic tumor from which it was derived, and the patient-matched normal genomes. When comparing somatic mutations identified in the cell culture and tissue genomes, we observe concordance at the majority of single nucleotide variants, whereas copy number changes are more variable. To understand the functional impact of non-coding somatic variation, we leveraged functional data generated by the ENCODE Project Consortium. We analyzed regulatory regions derived from multiple different cell types and found that melanocyte-specific regions are among the most depleted for somatic mutation accumulation. Significant depletion in other cell types suggests the metastatic melanoma cells de-differentiated to a more basal regulatory state. Experimental identification of genome-wide regulatory sites in two different melanoma samples supports this observation. Together, these results show that mutation accumulation in metastatic melanoma is nonrandom across the genome and that a de-differentiated regulatory architecture is common among different samples. Our findings enable identification of the underlying genetic components of melanoma and define the differences between a tissue-derived tumor sample and the cell culture created from it. Such information helps establish a broader mechanistic understanding of the linkage between non-coding genomic variations and the cellular evolution of cancer. PMID:22912592

  2. Expression of novel interleukin 2 binding molecules and their functional roles in human B cell differentiation.

    PubMed Central

    Tanaka, T; Saiki, O; Doi, S; Suemura, M; Negoro, S; Kishimoto, S

    1988-01-01

    Expressions and functional roles of novel IL-2 binding molecules (p70, 75) in the differentiation of B cells into Ig secreting cells were explored by using human several B cell lines and tonsillar B cells. Affinity-crosslinking studies revealed that five of nine B cell lines expressed p70 and p75 without detectable Tac antigen (p55) expression and the expression was associated with B cell maturation. In tonsillar B cells, small high-density B cells did not express p70 and p75, whereas large low-density B cells, which were thought to be activated in vivo, expressed them. Binding assays of radiolabeled IL-2 showed that the affinity of these molecules was intermediate (kD = 1-3 nM, 700-3,000 sites/cell). Furthermore, high concentrations of IL-2 (greater than 100 U/ml) induced Ig productions in large B cells and two of five cell lines. These results taken together suggest that B cells may express novel IL-2 binding molecules, associated with B cell differentiation and differentiate into Ig secreting cells by IL-2 through novel IL-2 binding molecules. Images PMID:2839549

  3. Differential PAX3 functions in normal skin melanocytes and melanoma cells

    SciTech Connect

    Medic, Sandra [School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Perth, WA (Australia)] [School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Perth, WA (Australia); Rizos, Helen [Westmead Institute for Cancer Research and Melanoma Institute of Australia, University of Sydney at Westmead Millennium Institute, Westmead, NSW (Australia)] [Westmead Institute for Cancer Research and Melanoma Institute of Australia, University of Sydney at Westmead Millennium Institute, Westmead, NSW (Australia); Ziman, Mel, E-mail: m.ziman@ecu.edu.au [School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Perth, WA (Australia) [School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Perth, WA (Australia); School of Pathology and Laboratory Medicine, University of Western Australia, Perth, WA (Australia)

    2011-08-12

    Highlights: {yields} PAX3 retains embryonic roles in adult melanocytes and melanoma cells. {yields} Promotes 'stem' cell-like phenotype via NES and SOX9 in both cells types. {yields} Regulates melanoma and melanocyte migration through MCAM and CSPG4. {yields} PAX3 regulates melanoma but not melanocyte proliferation via TPD52. {yields} Regulates melanoma cell (but not melanocyte) survival via BCL2L1 and PTEN. -- Abstract: The PAX3 transcription factor is the key regulator of melanocyte development during embryogenesis and is also frequently found in melanoma cells. While PAX3 is known to regulate melanocyte differentiation, survival, proliferation and migration during development, it is not clear if its function is maintained in adult melanocytes and melanoma cells. To clarify this we have assessed which genes are targeted by PAX3 in these cells. We show here that similar to its roles in development, PAX3 regulates complex differentiation networks in both melanoma cells and melanocytes, in order to maintain cells as 'stem' cell-like (via NES and SOX9). We show also that mediators of migration (MCAM and CSPG4) are common to both cell types but more so in melanoma cells. By contrast, PAX3-mediated regulation of melanoma cell proliferation (through TPD52) and survival (via BCL2L1 and PTEN) differs from that in melanocytes. These results suggest that by controlling cell proliferation, survival and migration as well as maintaining a less differentiated 'stem' cell like phenotype, PAX3 may contribute to melanoma development and progression.

  4. Tuft calcium spikes in accessory olfactory bulb mitral cells.

    PubMed

    Urban, Nathaniel N; Castro, Jason B

    2005-05-18

    The mammalian accessory olfactory system is critical for the detection and identification of pheromones and the representation of complex stimuli including sex, genetic relatedness, and individual identity. Mitral cells, the principal cells of the accessory olfactory bulb (AOB), receive monosynaptic input from the sensory periphery and already show highly specific response properties, firing selectively for combinations of genetic markers and gender-specific cues. Vomeronasal sensory neuron axons form synapses onto distal tuft-like branches of mitral cell primary dendrites. We have studied dendritic excitability and synaptic integration in AOB mitral cell dendrites, and we show that dendrites of accessory olfactory bulb mitral cells support action potential propagation and can fire regenerative spike-like events that are likely to contribute to the integration of inputs to these cells. These tuft spikes may be important for the specificity of AOB mitral cell responses. PMID:15901783

  5. Tuft Calcium Spikes in Accessory Olfactory Bulb Mitral Cells

    PubMed Central

    Urban, Nathaniel N.; Castro, Jason B.

    2005-01-01

    The mammalian accessory olfactory system is critical for the detection and identification of pheromones and the representation of complex stimuli including sex, genetic relatedness, and individual identity. Mitral cells, the principal cells of the accessory olfactory bulb (AOB), receive monosynaptic input from the sensory periphery and already show highly specific response properties, firing selectively for combinations of genetic markers and gender-specific cues. Vomeronasal sensory neuron axons form synapses onto distal tuft-like branches of mitral cell primary dendrites. We have studied dendritic excitability and synaptic integration in AOB mitral cell dendrites, and we show that dendrites of accessory olfactory bulb mitral cells support action potential propagation and can fire regenerative spike-like events that are likely to contribute to the integration of inputs to these cells. These tuft spikes may be important for the specificity of AOB mitral cell responses. PMID:15901783

  6. Identification of New Differentially Methylated Genes That Have Potential Functional Consequences in Prostate Cancer

    PubMed Central

    Kim, Jin W.; Kim, Seong-Tae; Turner, Aubrey R.; Young, Tracey; Smith, Shelly; Liu, Wennuan; Lindberg, Johan; Egevad, Lars; Gronberg, Henrik; Isaacs, William B.; Xu, Jianfeng

    2012-01-01

    Many differentially methylated genes have been identified in prostate cancer (PCa), primarily using candidate gene-based assays. Recently, several global DNA methylation profiles have been reported in PCa, however, each of these has weaknesses in terms of ability to observe global DNA methylation alterations in PCa. We hypothesize that there remains unidentified aberrant DNA methylation in PCa, which may be identified using higher resolution assay methods. We used the newly developed Illumina HumanMethylation450 BeadChip in PCa (n?=?19) and adjacent normal tissues (n?=?4) and combined these with gene expression data for identifying new DNA methylation that may have functional consequences in PCa development and progression. We also confirmed our methylation results in an independent data set. Two aberrant DNA methylation genes were validated among an additional 56 PCa samples and 55 adjacent normal tissues. A total 28,735 CpG sites showed significant differences in DNA methylation (FDR adjusted P<0.05), defined as a mean methylation difference of at least 20% between PCa and normal samples. Furthermore, a total of 122 genes had more than one differentially methylated CpG site in their promoter region and a gene expression pattern that was inverse to the direction of change in DNA methylation (e.g. decreased expression with increased methylation, and vice-versa). Aberrant DNA methylation of two genes, AOX1 and SPON2, were confirmed via bisulfate sequencing, with most of the respective CpG sites showing significant differences between tumor samples and normal tissues. The AOX1 promoter region showed hypermethylation in 92.6% of 54 tested PCa samples in contrast to only three out of 53 tested normal tissues. This study used a new BeadChip combined with gene expression data in PCa to identify novel differentially methylated CpG sites located within genes. The newly identified differentially methylated genes may be used as biomarkers for PCa diagnosis. PMID:23119026

  7. Functional Relationships between Genes Associated with Differentiation Potential of Aged Myogenic Progenitors

    PubMed Central

    Nagarajan, Radhakrishnan; Datta, Sujay; Scutari, Marco; Beggs, Marjorie L.; Nolen, Greg T.; Peterson, Charlotte A.

    2010-01-01

    Aging is accompanied by considerable heterogeneity with possible co-expression of differentiation pathways. The present study investigates the interplay between crucial myogenic, adipogenic, and Wnt-related genes orchestrating aged myogenic progenitor differentiation (AMPD) using clonal gene expression profiling in conjunction with Bayesian structure learning (BSL) techniques. The expression of three myogenic regulatory factor genes (Myogenin, Myf-5, MyoD1), four genes involved in regulating adipogenic potential (C/EBP?, DDIT3, FoxC2, PPAR?), and two genes in the Wnt signaling pathway (Lrp5, Wnt5a) known to influence both differentiation programs were determined across 34 clones by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Three control genes were used for normalization of the clonal expression data (18S, GAPDH, and B2M). Constraint-based BSL techniques, namely (a) PC Algorithm, (b) Grow-shrink (GS) algorithm, and (c) Incremental Association Markov Blanket (IAMB) were used to model the functional relationships (FRs) in the form of acyclic networks from the clonal expression profiles. A novel resampling approach that obviates the need for a user-defined confidence threshold is proposed to identify statistically significant FRs at small sample sizes. Interestingly, the resulting acyclic network consisted of FRs corresponding to myogenic, adipogenic, Wnt-related genes and their interaction. A significant number of these FRs were robust to normalization across the three house-keeping genes and the choice of the BSL technique. The results presented elucidate the delicate balance between differentiation pathways (i.e., myogenic as well as adipogenic) and possible cross-talk between pathways in AMPD. PMID:21423363

  8. Instrumented Functional Reach Test Differentiates Individuals at High Risk for Parkinson’s Disease from Controls

    PubMed Central

    Hasmann, Sandra E.; Berg, Daniela; Hobert, Markus A.; Weiss, David; Lindemann, Ulrich; Streffer, Johannes; Liepelt-Scarfone, Inga; Maetzler, Walter

    2014-01-01

    The functional reach (FR) test as a complex measure of balance including limits of stability has been proven to differentiate between patients with Parkinson’s disease (PD) and controls (CO). Recently, it has been shown that the instrumentation of the FR (iFR) with a wearable sensor may increase this diagnostic accuracy. This cross-sectional study aimed at investigating whether the iFR has the potential to differentiate individuals with high risk for PD (HRPD) from CO, as the delineation of such individuals would allow for, e.g., early neuromodulation. Thirteen PD patients, 13 CO, and 31 HRPD were investigated. HRPD was defined by presence of an enlarged area of hyperechogenicity in the mesencephalon on transcranial sonography and either one motor sign or two risk and prodromal markers of PD. All participants were asked to reach with their right arm forward as far as possible and hold this position for 10?s. During this period, sway parameters were assessed with an accelerometer (Dynaport, McRoberts) worn at the lower back. Extracted parameters that differed significantly between PD patients and CO in our cohort [FR distance (shorter in PD), anterior–posterior and mediolateral acceleration (both lower in PD)] as well as JERK, which has been shown to differentiate HRPD from CO and PD in a previous study, were included in a model, which was then used to differentiate HRPD from CO. The model yielded an area under the curve of 0.77, with a specificity of 85%, and a sensitivity of 74%. These results suggest that the iFR can contribute to an assessment panel focusing on the definition of HRPD individuals. PMID:25386137

  9. Instrumented functional reach test differentiates individuals at high risk for Parkinson's disease from controls.

    PubMed

    Hasmann, Sandra E; Berg, Daniela; Hobert, Markus A; Weiss, David; Lindemann, Ulrich; Streffer, Johannes; Liepelt-Scarfone, Inga; Maetzler, Walter

    2014-01-01

    The functional reach (FR) test as a complex measure of balance including limits of stability has been proven to differentiate between patients with Parkinson's disease (PD) and controls (CO). Recently, it has been shown that the instrumentation of the FR (iFR) with a wearable sensor may increase this diagnostic accuracy. This cross-sectional study aimed at investigating whether the iFR has the potential to differentiate individuals with high risk for PD (HRPD) from CO, as the delineation of such individuals would allow for, e.g., early neuromodulation. Thirteen PD patients, 13 CO, and 31 HRPD were investigated. HRPD was defined by presence of an enlarged area of hyperechogenicity in the mesencephalon on transcranial sonography and either one motor sign or two risk and prodromal markers of PD. All participants were asked to reach with their right arm forward as far as possible and hold this position for 10?s. During this period, sway parameters were assessed with an accelerometer (Dynaport, McRoberts) worn at the lower back. Extracted parameters that differed significantly between PD patients and CO in our cohort [FR distance (shorter in PD), anterior-posterior and mediolateral acceleration (both lower in PD)] as well as JERK, which has been shown to differentiate HRPD from CO and PD in a previous study, were included in a model, which was then used to differentiate HRPD from CO. The model yielded an area under the curve of 0.77, with a specificity of 85%, and a sensitivity of 74%. These results suggest that the iFR can contribute to an assessment panel focusing on the definition of HRPD individuals. PMID:25386137

  10. A giant serous cystadenoma developing in an accessory ovary

    Microsoft Academic Search

    Muhyittin Temiz; Ahmet Aslan; Arif Gungoren; Güvenç Diner; Sinem Karazincir

    2008-01-01

    Background  Accessory ovaries are rare anomalies and cysts arising from accessory ovaries are extremely rare. Their reported incidence\\u000a is 1\\/29,000–1\\/700,000. Establishing the diagnosis preoperatively is difficult. Radiologic methods are usually inadequate in\\u000a recognizing the origin of these tumors. Thus, they are usually confused with other intraabdominal tumors.\\u000a \\u000a \\u000a \\u000a Case  A 22-year-old nulliparous girl presented with abdominal pain and tumoral growth for 1.5 years. Abdominal

  11. Osteochondrosis of the accessory ossification centre of the medial malleolus.

    PubMed

    Farsetti, Pasquale; Dragoni, Massimiliano; Potenza, Vito; Caterini, Roberto

    2015-01-01

    We report a case of a painful accessory ossification centre of the medial malleolus in an 11-year-old girl who was not involved in sports activities. The patient was treated conservatively, with complete clinical and radiographic healing of the medial malleolus 6 months after the first presentation. We ruled out the uncommon pathological conditions causing chronic pain in the medial malleolus during skeletal growth, such as traction apophysitis of the medial malleolus, osteochondrosis, osteochondritis or avascular necrosis of the distal tibial epiphysis. We speculate that this painful condition may be classified as an osteochondrosis of the accessory ossification centre of the medial malleolus. PMID:25438106

  12. Chemocauterization of Congenital Fistula from the Accessory Parotid Gland

    PubMed Central

    Kim, Bong Jik; Sung, Myung-Whun; Kim, Kwang Hyun

    2008-01-01

    Congenital sialo-cutaneous fistula arising from the accessory parotid gland is extremely rare. Although the fistula tract can be successfully excised after making a skin incision along the skin tension line around the fistula opening, a facial scar inevitably remains. We here report a case of sialo-cutaneous fistula that was treated with chemocauterization with trichloroacetic acid (TCA). TCA cauterization is an easy and effective option for the treatment of congenital fistula from an accessory parotid gland, especially from the aesthetic point of view. PMID:19434283

  13. Transcription. CTCF establishes discrete functional chromatin domains at the Hox clusters during differentiation.

    PubMed

    Narendra, Varun; Rocha, Pedro P; An, Disi; Raviram, Ramya; Skok, Jane A; Mazzoni, Esteban O; Reinberg, Danny

    2015-02-27

    Polycomb and Trithorax group proteins encode the epigenetic memory of cellular positional identity by establishing inheritable domains of repressive and active chromatin within the Hox clusters. Here we demonstrate that the CCCTC-binding factor (CTCF) functions to insulate these adjacent yet antagonistic chromatin domains during embryonic stem cell differentiation into cervical motor neurons. Deletion of CTCF binding sites within the Hox clusters results in the expansion of active chromatin into the repressive domain. CTCF functions as an insulator by organizing Hox clusters into spatially disjoint domains. Ablation of CTCF binding disrupts topological boundaries such that caudal Hox genes leave the repressed domain and become subject to transcriptional activation. Hence, CTCF is required to insulate facultative heterochromatin from impinging euchromatin to produce discrete positional identities. PMID:25722416

  14. CTCF establishes discrete functional chromatin domains at the Hox clusters during differentiation

    PubMed Central

    Narendra, Varun; Rocha, Pedro P.; An, Disi; Raviram, Ramya; Skok, Jane A.; Mazzoni, Esteban O.; Reinberg, Danny

    2015-01-01

    Polycomb and trithorax group proteins encode the epigenetic memory of cellular positional identity by establishing inheritable domains of repressive and active chromatin within the Hox clusters. Here, we demonstrate that the CCCTC-binding factor (CTCF) functions to insulate these adjacent yet antagonistic chromatin domains during embryonic stem cell differentiation into cervical motor neurons. Deletion of CTCF binding sites within the Hox clusters results in the expansion of active chromatin into the repressive domain. CTCF functions as an insulator by organizing Hox clusters into spatially disjoint domains. Ablation of CTCF binding disrupts topological boundaries such that caudal Hox genes leave the repressed domain and become subject to transcriptional activation. Hence, CTCF is required to insulate facultative heterochromatin from impinging euchromatin to produce discrete positional identities. PMID:25722416

  15. Identification of a Novel Cryptochrome Differentiating Domain Required for Feedback Repression in Circadian Clock Function*

    PubMed Central

    Khan, Sanjoy K.; Xu, Haiyan; Ukai-Tadenuma, Maki; Burton, Brittany; Wang, Yongmei; Ueda, Hiroki R.; Liu, Andrew C.

    2012-01-01

    Circadian clocks in mammals are based on a negative feedback loop in which transcriptional repression by the cryptochromes, CRY1 and CRY2, lies at the heart of the mechanism. Despite similarities in sequence, domain structure, and biochemical activity, they play distinct roles in clock function. However, detailed biochemical studies have not been straightforward and Cry function has not been examined in real clock cells using kinetic measurements. In this study, we demonstrate, through cell-based genetic complementation and real-time molecular recording, that Cry1 alone is able to maintain cell-autonomous circadian rhythms, whereas Cry2 cannot. Using this novel functional assay, we identify a cryptochrome differentiating ?-helical domain within the photolyase homology region (PHR) of CRY1, designated as CRY1-PHR(313–426), that is required for clock function and distinguishes CRY1 from CRY2. Contrary to speculation, the divergent carboxyl-terminal tail domain (CTD) is dispensable, but serves to modulate rhythm amplitude and period length. Finally, we identify the biochemical basis of their distinct function; CRY1 is a much more potent transcriptional repressor than CRY2, and the strength of repression by various forms of CRY proteins significantly correlates with rhythm amplitude. Taken together, our results demonstrate that CRY1-PHR(313–426), not the divergent CTD, is critical for clock function. These findings provide novel insights into the evolution of the diverse functions of the photolyase/cryptochrome family of flavoproteins and offer new opportunities for mechanistic studies of CRY function. PMID:22692217

  16. HIV-1 Nef Sequence and Functional Compartmentalization in the Gut Is Not Due to Differential Cytotoxic T Lymphocyte Selective Pressure

    PubMed Central

    Lewis, Martha J.; Frohnen, Patricia; Ibarrondo, F. Javier; Reed, Diane; Iyer, Varun; Ng, Hwee L.; Elliott, Julie; Yang, Otto O.; Anton, Peter

    2013-01-01

    The gut is the largest lymphoid organ in the body and a site of active HIV-1 replication and immune surveillance. The gut is a reservoir of persistent infection in some individuals with fully suppressed plasma viremia on combination antiretroviral therapy (cART) although the cause of this persistence is unknown. The HIV-1 accessory protein Nef contributes to persistence through multiple functions including immune evasion and increasing infectivity. Previous studies showed that Nef’s function is shaped by cytotoxic T lymphocyte (CTL) responses and that there are distinct populations of Nef within tissue compartments. We asked whether Nef’s sequence and/or function are compartmentalized in the gut and how compartmentalization relates to local CTL immune responses. Primary nef quasispecies from paired plasma and sigmoid colon biopsies from chronically infected subjects not on therapy were sequenced and cloned into Env? Vpu? pseudotyped reporter viruses. CTL responses were mapped by IFN-? ELISpot using expanded CD8+ cells from blood and gut with pools of overlapping peptides covering the entire HIV proteome. CD4 and MHC Class I Nef-mediated downregulation was measured by flow cytometry. Multiple tests indicated compartmentalization of nef sequences in 5 of 8 subjects. There was also compartmentalization of function with MHC Class I downregulation relatively well preserved, but significant loss of CD4 downregulation specifically by gut quasispecies in 5 of 7 subjects. There was no compartmentalization of CTL responses in 6 of 8 subjects, and the selective pressure on quasispecies correlated with the magnitude CTL response regardless of location. These results demonstrate that Nef adapts via diverse pathways to local selective pressures within gut mucosa, which may be predominated by factors other than CTL responses such as target cell availability. The finding of a functionally distinct population within gut mucosa offers some insight into how HIV-1 may persist in the gut despite fully suppressed plasma viremia on cART. PMID:24058696

  17. An analysis of differential item functioning by gender in the Learning Disability Screening Questionnaire (LDSQ).

    PubMed

    Murray, Aja Louise; Booth, Tom; McKenzie, Karen

    2015-04-01

    The Learning Disability Screening Questionnaire (LDSQ; McKenzie & Paxton, 2006) was developed as a brief screen for intellectual disability. Although several previous studies have evaluated the LDSQ with respect to its utility as a clinical and research tool, no studies have considered the fairness of the test across males and females. In the current study we, therefore, used a multi-group item response theory approach to assess differential item functioning across gender in a sample of 211 males and 132 females assessed in clinical and forensic settings. Although the test did not show evidence of differential item functioning by gender, it was necessary to exclude one item due to estimation problems and to combine two very highly related items (concerning reading and writing ability) into a single literacy item Thus, in addition to being generally supportive of the utility of the LDSQ, our results also highlight possible areas of weakness in the tool and suggest possible amendments that could be made to test content to improve the test in future revisions. PMID:25677033

  18. Differential Item Functioning of Pathological Gambling Criteria: An Examination of Gender, Race/Ethnicity, and Age

    PubMed Central

    Torres, Luis R.; Cunningham-Williams, Renee M.; Woods, Carol; Unick, G. Jay

    2015-01-01

    This study tested for the presence of differential item functioning (DIF) in DSM-IV Pathological Gambling Disorder (PGD) criteria based on gender, race/ethnicity and age. Using a nationally representative sample of adults from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), indicating current gambling (n = 10,899), Multiple Indicator-Multiple Cause (MIMIC) models tested for DIF, controlling for income, education, and marital status. Compared to the reference groups (i.e., Male, Caucasian, and ages 25–59 years), women (OR = 0.62; P < .001) and Asian Americans (OR = 0.33; P < .001) were less likely to endorse preoccupation (Criterion 1). Women were more likely to endorse gambling to escape (Criterion 5) (OR = 2.22; P < .001) but young adults (OR = 0.62; P < .05) were less likely to endorse it. African Americans (OR = 2.50; P < .001) and Hispanics were more likely to endorse trying to cut back (Criterion 3) (OR = 2.01; P < .01). African Americans were more likely to endorse the suffering losses (OR = 2.27; P < .01) criterion. Young adults were more likely to endorse chasing losses (Criterion 9) (OR = 1.81; P < .01) while older adults were less likely to endorse this criterion (OR = 0.76; P < .05). Further research is needed to identify factors contributing to DIF, address criteria level bias, and examine differential test functioning. PMID:20623329

  19. Analyte species and concentration identification using differentially functionalized microcantilever arrays and artificial neural networks

    SciTech Connect

    Senesac, Larry R [ORNL; Datskos, Panos G [ORNL; Sepaniak, Michael J [ORNL

    2006-01-01

    In the present work, we have performed analyte species and concentration identification using an array of ten differentially functionalized microcantilevers coupled with a back-propagation artificial neural network pattern recognition algorithm. The array consists of ten nanostructured silicon microcantilevers functionalized by polymeric and gas chromatography phases and macrocyclic receptors as spatially dense, differentially responding sensing layers for identification and quantitation of individual analyte(s) and their binary mixtures. The array response (i.e. cantilever bending) to analyte vapor was measured by an optical readout scheme and the responses were recorded for a selection of individual analytes as well as several binary mixtures. An artificial neural network (ANN) was designed and trained to recognize not only the individual analytes and binary mixtures, but also to determine the concentration of individual components in a mixture. To the best of our knowledge, ANNs have not been applied to microcantilever array responses previously to determine concentrations of individual analytes. The trained ANN correctly identified the eleven test analyte(s) as individual components, most with probabilities greater than 97%, whereas it did not misidentify an unknown (untrained) analyte. Demonstrated unique aspects of this work include an ability to measure binary mixtures and provide both qualitative (identification) and quantitative (concentration) information with array-ANN-based sensor methodologies.

  20. Trichostatin A, a critical factor in maintaining the functional differentiation of primary cultured rat hepatocytes

    SciTech Connect

    Henkens, Tom [Department of Toxicology, Pharmaceutical Institute, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels (Belgium)]. E-mail: Tom.Henkens@vub.ac.be; Papeleu, Peggy [Department of Toxicology, Pharmaceutical Institute, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels (Belgium); Elaut, Greetje [Department of Toxicology, Pharmaceutical Institute, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels (Belgium); Vinken, Mathieu [Department of Toxicology, Pharmaceutical Institute, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels (Belgium); Rogiers, Vera [Department of Toxicology, Pharmaceutical Institute, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels (Belgium); Vanhaecke, Tamara [Department of Toxicology, Pharmaceutical Institute, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels (Belgium)

    2007-01-01

    Histone deacetylase inhibitors (HDI) have been shown to increase differentiation-related gene expression in several tumor-derived cell lines by hyperacetylating core histones. Effects of HDI on primary cultured cells, however, have hardly been investigated. In the present study, the ability of trichostatin A (TSA), a prototype hydroxamate HDI, to counteract the loss of liver-specific functions in primary rat hepatocyte cultures has been investigated. Upon exposure to TSA, it was found that the cell viability of the cultured hepatocytes and their albumin secretion as a function of culture time were increased. TSA-treated hepatocytes also better maintained cytochrome P450 (CYP)-mediated phase I biotransformation capacity, whereas the activity of phase II glutathione S-transferases (GST) was not affected. Western blot and qRT-PCR analysis of CYP1A1, CYP2B1 and CYP3A11 protein and mRNA levels, respectively, further revealed that TSA acts at the transcriptional level. In addition, protein expression levels of the liver-enriched transcription factors (LETFs) hepatic nuclear factor 4 alpha (HNF4{alpha}) and CCAAT/enhancer binding protein alpha (C/EBP{alpha}) were accordingly increased by TSA throughout culture time. In conclusion, these findings indicate that TSA plays a major role in the preservation of the differentiated hepatic phenotype in culture. It is suggested that the effects of TSA on CYP gene expression are mediated via controlling the expression of LETFs.

  1. Androgens induce sebaceous differentiation in sebocyte cells expressing a stable functional androgen receptor.

    PubMed

    Barrault, Christine; Garnier, Julien; Pedretti, Nathalie; Cordier-Dirikoc, Sevda; Ratineau, Emeline; Deguercy, Alain; Bernard, François-Xavier

    2015-08-01

    Androgens act through non-genomic and androgen receptor (AR)-dependent genomic mechanisms. AR is expressed in the sebaceous gland and the importance of androgens in the sebaceous function is well established. However, the in vitro models used to date have failed to evidence a clear genomic effect (e.g., modification of gene expression profile) of androgens on human sebocyte cells. In order to study the impact of active androgens in sebocytes, we constructed a stable human sebocyte cell line derived from SEBO662 [17] constitutively expressing a fully functional AR. In these SEBO662 AR+ cells, dihydrotestosterone (DHT) induced AR nuclear translocation and the strong modulation of a set of transcripts (RASD1, GREB1…) known to be androgen-sensitive in other androgenic cells and tissues. Moreover, we observed that DHT precociously down-regulated markers for immature follicular cells (KRT15, TNC) and for hair lineage (KRT75, FST) and up-regulated the expression of genes potentially related to sebocyte differentiation (MUC1/EMA, AQP3, FADS2). These effects were fully confirmed at the protein level. In addition, DHT-stimulated SEBO662 AR+, cultured in a low-calcium defined keratinocyte medium without serum or any complement, neosynthesize lipids, including sebum lipids, and store increased amounts of triglycerides in lipid droplets. DHT also induces morphological changes, increases cell size, and treatments over 7 days lead to a time-dependent increase in the population of apoptotic DNA-fragmented cells. Taken together, these results show for the first time that active androgens alone can engage immature sebocytes in a clear lipogenic differentiation process (Graphical abstract). These effects depend on the expression of a functional AR in these cells. This model should be of interest for revisiting the mechanisms of the sebaceous function in vitro and for the design of relevant pharmacological models for drug or compound testing. PMID:25864624

  2. Structural and Mutational Analysis of Functional Differentiation between Synaptotagmins-1 and -7

    SciTech Connect

    Xue, Mingshan; Craig, Timothy K.; Shin, Ok-Ho; Li, Liyi; Brautigam, Chad A.; Tomchick, Diana R.; Südhof, Thomas C.; Rosenmund, Christian; Rizo, Josep (Baylor); (UTSMC); (Texas)

    2012-01-20

    Synaptotagmins are known to mediate diverse forms of Ca{sup 2+}-triggered exocytosis through their C{sub 2} domains, but the principles underlying functional differentiation among them are unclear. Synaptotagmin-1 functions as a Ca{sup 2+} sensor in neurotransmitter release at central nervous system synapses, but synaptotagmin-7 does not, and yet both isoforms act as Ca{sup 2+} sensors in chromaffin cells. To shed light into this apparent paradox, we have performed rescue experiments in neurons from synaptotagmin-1 knockout mice using a chimera that contains the synaptotagmin-1 sequence with its C{sub 2}B domain replaced by the synaptotagmin-7 C{sub 2}B domain (Syt1/7). Rescue was not achieved either with the WT Syt1/7 chimera or with nine mutants where residues that are distinct in synaptotagmin-7 were restored to those present in synaptotagmin-1. To investigate whether these results arise because of unique conformational features of the synaptotagmin-7 C{sub 2}B domain, we determined its crystal structure at 1.44 {angstrom} resolution. The synaptotagmin-7 C{sub 2}B domain structure is very similar to that of the synaptotagmin-1 C{sub 2}B domain and contains three Ca{sup 2+}-binding sites. Two of the Ca{sup 2+}-binding sites of the synaptotagmin-7 C{sub 2}B domain are also present in the synaptotagmin-1 C{sub 2}B domain and have analogous ligands to those determined for the latter by NMR spectroscopy, suggesting that a discrepancy observed in a crystal structure of the synaptotagmin-1 C{sub 2}B domain arose from crystal contacts. Overall, our results suggest that functional differentiation in synaptotagmins arises in part from subtle sequence changes that yield dramatic functional differences.

  3. 6035 Hg(Ar) Lamp in 6058 Fiber Optic Accessory. Pencil Style Calibration Lamps

    E-print Network

    Woodall, Jerry M.

    6035 Hg(Ar) Lamp in 6058 Fiber Optic Accessory. Pencil Style Calibration Lamps Compact and simple, and spectral radiometers. We also offer a full range of accessories, from mounts and holders, to fiber optic

  4. 41 CFR 101-39.304 - Modification or installation of accessory equipment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...GSA Interagency Fleet Management System Vehicles § 101-39...installation of accessory equipment. The modification of a GSA Interagency Fleet Management System (IFMS) vehicle...installation of accessory equipment on these...

  5. 41 CFR 101-39.304 - Modification or installation of accessory equipment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...GSA Interagency Fleet Management System Vehicles § 101-39...installation of accessory equipment. The modification of a GSA Interagency Fleet Management System (IFMS) vehicle...installation of accessory equipment on these...

  6. 41 CFR 101-39.304 - Modification or installation of accessory equipment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...GSA Interagency Fleet Management System Vehicles § 101-39...installation of accessory equipment. The modification of a GSA Interagency Fleet Management System (IFMS) vehicle...installation of accessory equipment on these...

  7. 41 CFR 101-39.304 - Modification or installation of accessory equipment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...GSA Interagency Fleet Management System Vehicles § 101-39...installation of accessory equipment. The modification of a GSA Interagency Fleet Management System (IFMS) vehicle...installation of accessory equipment on these...

  8. 41 CFR 101-39.304 - Modification or installation of accessory equipment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...GSA Interagency Fleet Management System Vehicles § 101-39...installation of accessory equipment. The modification of a GSA Interagency Fleet Management System (IFMS) vehicle...installation of accessory equipment on these...

  9. 21 CFR 884.6190 - Assisted reproductive microscopes and microscope accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...which are classified under assisted reproduction accessories) are optical instruments used to enlarge images of gametes or embryos. Variations of microscopes and accessories used for these purposes would include phase contrast microscopes, dissecting...

  10. 21 CFR 884.6190 - Assisted reproductive microscopes and microscope accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...which are classified under assisted reproduction accessories) are optical instruments used to enlarge images of gametes or embryos. Variations of microscopes and accessories used for these purposes would include phase contrast microscopes, dissecting...

  11. 21 CFR 884.6190 - Assisted reproductive microscopes and microscope accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...which are classified under assisted reproduction accessories) are optical instruments used to enlarge images of gametes or embryos. Variations of microscopes and accessories used for these purposes would include phase contrast microscopes, dissecting...

  12. 21 CFR 884.4150 - Bipolar endoscopic coagulator-cutter and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Bipolar endoscopic coagulator-cutter and accessories...Gynecological Surgical Devices § 884.4150 Bipolar endoscopic coagulator-cutter and accessories. (a) Identification. A bipolar endoscopic...

  13. 21 CFR 884.4150 - Bipolar endoscopic coagulator-cutter and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Bipolar endoscopic coagulator-cutter and accessories...Gynecological Surgical Devices § 884.4150 Bipolar endoscopic coagulator-cutter and accessories. (a) Identification. A bipolar endoscopic...

  14. 77 FR 67261 - Airworthiness Directives; Aeronautical Accessories, Inc., High Landing Gear Forward Crosstube...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-09

    ...Directives; Aeronautical Accessories, Inc., High Landing Gear Forward Crosstube...directive (AD) for Aeronautical Accessories, Inc. (AAI) high landing gear forward crosstube...AB412EP; and Bell Helicopter Textron, Inc. (Bell) Model 205A, 205A-1,...

  15. 77 FR 37768 - Airworthiness Directives; Aeronautical Accessories, Inc., High Landing Gear Aft Crosstube Assembly

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-25

    ...Directives; Aeronautical Accessories, Inc., High Landing Gear Aft Crosstube Assembly...AD) for the Aeronautical Accessories, Inc. (AAI), High Landing Gear Aft Crosstube...installed on certain Bell Helicopter Textron, Inc. (Bell) and Agusta S.p.A....

  16. Small things considered: the small accessory subunits of RNA polymerase in Gram-positive bacteria.

    PubMed

    Weiss, Andy; Shaw, Lindsey N

    2015-07-01

    The DNA-dependent RNA polymerase core enzyme in Gram-positive bacteria consists of seven subunits. Whilst four of them (?2??(')) are essential, three smaller subunits, ?, ? and ? (?9-21.5 kDa), are considered accessory. Both ? and ? have been viewed as integral components of RNAP for several decades; however, ? has only recently been described. Functionally these three small subunits carry out a variety of tasks, imparting important, supportive effects on the transcriptional process of Gram-positive bacteria. While ? is thought to have a wide range of roles, reaching from maintaining structural integrity of RNAP to ? factor recruitment, the only suggested function for ? thus far is in protecting cells from phage infection. The third subunit, ?, has been shown to have distinct influences in maintaining transcriptional specificity, and thus has a key role in cellular fitness. Collectively, all three accessory subunits, although dispensable under laboratory conditions, are often thought to be crucial for proper RNAP function. Herein we provide an overview of the available literature on each subunit, summarizing landmark findings that have deepened our understanding of these proteins and their function, and outline future challenges in understanding the role of these small subunits in the transcriptional process. PMID:25878038

  17. Regulation of STREX BK channels by the ?4 Accessory Subunit

    PubMed Central

    Petrik, David; Brenner, Robert

    2007-01-01

    Large conductance (BK-type) calcium-activated potassium channels utilize alternative splicing and association with accessory ? subunits to tailor BK channel properties to diverse cell types. Two important modulators of BK channel gating are the neuronal-specific ?4 subunit and alternative splicing at the STREX exon. Individually, these modulators affect the gating properties of the BK channel as well as its response to phosphorylation. In this study, the combined functional consequences of STREX and the ?4 subunit on BK channel biophysical properties were investigated in transfected HEK293 cells. Surprisingly, we found that the combined effects of STREX and ?4 are non-additive and even opposite for some properties. At high calcium, ?4 or the STREX exon individually share properties that promote BK channel opening via slowing of deactivation. However, the combined effects are a speeding of deactivation and a decreased open probability. ?4 also inhibits BK channel opening by a slowing of activation. This effect occurs across calcium concentrations in the absence of STREX, but predominates only at low calcium for STREX containing channels. BK channel response to phosphorylation status are also altered by the combination of the ?4 subunit and the STREX exon. ?4/STREX channels show a slowing of activation kinetics following dephosphorylation whereas ?4 channels lacking STREX do not. In contrast, ?4 confers a speeding of activation in response to cAMP-dependent phosphorylation in channels lacking STREX, but not in channels containing the STREX exon. These results indicate that the combination of the ?4 subunit and STREX exon confer non-additive and unique properties to BK channels. Analysis of expression in brain slices suggests that STREX and ?4 mRNA overlap expression in the dentate gyrus of the hippocampus and the cerebellar purkinje cells, suggesting that these unique properties of BK channels may underlie BK channel gating in these cells. PMID:17945424

  18. Cells of a multicellular organism are functionally heterogeneous owing to the differential expression of genes. Historically, differential gene

    E-print Network

    Cai, Long

    demonstrated that adult cells are genetically equivalent to early embryonic cells, and that differential gene of this technology for custom-tailored cell therapy. However, although nuclear transfer remains the tool of choice. Cancer cells usually undergo both genetic and epigenetic changes that cause a block in terminal

  19. Walking versus breathing: mechanical differentiation of sea urchin podia corresponds to functional specialization.

    PubMed

    Leddy, H A; Johnson, A S

    2000-02-01

    The podia of sea urchins function in locomotion, adhesion, feeding, and respiration; but different podia on a single urchin are often specialized to one or more of these tasks. We examined the morphology and material properties of podia of the green sea urchin, Strongylocentrotus droebachiensis, to determine whether, despite apparent similarities, they achieve functional specialization along the oral-aboral axis through the differentiation of distinct mechanical properties. We found that oral podia, which are used primarily for locomotion and adhesion, are stronger and thicker than aboral podia, which are used primarily for capturing drift material and as a respiratory surface. The functional role of ambital podia is more ambiguous; however, they are longer and are extended at a lower strain rate than other podial types. They are also stronger and stiffer than aboral podia. In addition, all podia become stronger and stiffer when extended at faster strain rates, in some cases by nearly an order of magnitude for an order of magnitude change in strain rate. This strain-rate dependence implies that resistance to rapid loading such as that imposed by waves is high compared to resistance to slower, self-imposed loads. Thus, the serially arranged podia of S. droebachiensis are functionally specialized along an oral-aboral axis by differences in their morphology and mechanical properties. PMID:10707816

  20. On convergence of differential evolution over a class of continuous functions with unique global optimum.

    PubMed

    Ghosh, Sayan; Das, Swagatam; Vasilakos, Athanasios V; Suresh, Kaushik

    2012-02-01

    Differential evolution (DE) is arguably one of the most powerful stochastic real-parameter optimization algorithms of current interest. Since its inception in the mid 1990s, DE has been finding many successful applications in real-world optimization problems from diverse domains of science and engineering. This paper takes a first significant step toward the convergence analysis of a canonical DE (DE/rand/1/bin) algorithm. It first deduces a time-recursive relationship for the probability density function (PDF) of the trial solutions, taking into consideration the DE-type mutation, crossover, and selection mechanisms. Then, by applying the concepts of Lyapunov stability theorems, it shows that as time approaches infinity, the PDF of the trial solutions concentrates narrowly around the global optimum of the objective function, assuming the shape of a Dirac delta distribution. Asymptotic convergence behavior of the population PDF is established by constructing a Lyapunov functional based on the PDF and showing that it monotonically decreases with time. The analysis is applicable to a class of continuous and real-valued objective functions that possesses a unique global optimum (but may have multiple local optima). Theoretical results have been substantiated with relevant computer simulations. PMID:21791412

  1. Collagen functionalized bioactive nanofiber matrices for osteogenic differentiation of mesenchymal stem cells: bone tissue engineering.

    PubMed

    Cheng, Yixing; Ramos, Daisy; Lee, Paul; Liang, Danni; Yu, Xiaojun; Kumbar, Sangamesh G

    2014-02-01

    Scaffold architecture, surface topography, biochemical and mechanical cues have been shown to significantly improve cellular events and in vivo tissue regeneration. Specifically electrospun nanofiber matrices have gained tremendous interest due to their intrinsic structural resemblance to native tissue extracellular matrix (ECM). The present study reports on the electrospun nanofiber matrices of polycaprolactone (PCL)-chitosan (CS) blends and effect of type I collagen surface functionalization in regulating rat bone marrow derived stromal cells (rBMSCs) differentiation into osteogenic lineage. Collagen was covalently attached to blend nanofibers via carbodiimide (EDC) coupling. Bead-free smooth nanofibers (diameter-700-850 nm) obtained at the optimized conditions of polymer concentration and electrospinning parameters were used for the study. EDC collagen coupling resulted in 0.120+/-0.016 micro g of collagen immobilization onto a 1 cm2 area of the PCL/CS nanofibers, which was 2.6-folds higher than the amount of collagen that can be retained by physical adsorption. Significantly improved rBMSCs adhesion, spreading, proliferation and osteogenic differentiation was observed on the collagen functionalized COL-PCULCS nanofiber matrices as compared to control groups. Osteogenic phenotypic markers such as alkaline phosphatase (ALP) activity and mineralization were found to be significantly higher on COL-PCL/CS nanofiber matrices as compared to controls. Elevated gene expression profiles of osteogenic markers such as osteocalcin (0CN), osteopontin (OPN) and ALP further corroborate the osteoinductive nature of the collagen functionalized PCL/CS nanofiber matrices. These fiber matrices and modification techniques could be extended to other scaffold systems for tissue engineering applications. PMID:24738337

  2. Effectiveness of Combining Statistical Tests and Effect Sizes When Using Logistic Discriminant Function Regression to Detect Differential Item Functioning for Polytomous Items

    ERIC Educational Resources Information Center

    Gómez-Benito, Juana; Hidalgo, Maria Dolores; Zumbo, Bruno D.

    2013-01-01

    The objective of this article was to find an optimal decision rule for identifying polytomous items with large or moderate amounts of differential functioning. The effectiveness of combining statistical tests with effect size measures was assessed using logistic discriminant function analysis and two effect size measures: R[superscript 2] and…

  3. Efficiency of the Mantel, Generalized Mantel-Haenszel, and Logistic Discriminant Function Analysis Methods in Detecting Differential Item Functioning for Polytomous Items

    ERIC Educational Resources Information Center

    Su, Ya-Hui; Wang, Wen-Chung

    2005-01-01

    Simulations were conducted to investigate factors that influence the Mantel, generalized Mantel-Haenszel (GMH), and logistic discriminant function analysis (LDFA) methods in assessing differential item functioning (DIF) for polytomous items. The results show that the magnitude of DIF contamination in the matching score, as measured by the average…

  4. The accessory middle cerebral artery (AMCA). Diagnostic and therapeutic consequences

    Microsoft Academic Search

    A. Abanou; P. Lasjaunias; C. Manelfe; L. Lopez-Ibor

    1984-01-01

    Summary The existence of the accessory middle cerebral artery (AMCA) is a rare anatomical variation with an estimated incidence of 0.31%. The embryological development of this artery is unknown. Three anatomical subtypes are described: in the type 1 variety the AMCA arises from the internal carotid artery; in the type 2, the AMCA originates from the proximal part of the

  5. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 false Abrasive device and accessories. 872...SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous...in § 872.9. If the device is not labeled or otherwise...of the quality system regulation in part 820 of this...

  6. 21 CFR 872.4120 - Bone cutting instrument and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Identification. A bone cutting instrument and accessories is a metal device intended for use in reconstructive oral surgery to drill or cut into the upper or lower jaw and may be used to prepare bone to insert a wire, pin, or screw....

  7. 21 CFR 872.4120 - Bone cutting instrument and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Identification. A bone cutting instrument and accessories is a metal device intended for use in reconstructive oral surgery to drill or cut into the upper or lower jaw and may be used to prepare bone to insert a wire, pin, or screw....

  8. 21 CFR 872.4120 - Bone cutting instrument and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Identification. A bone cutting instrument and accessories is a metal device intended for use in reconstructive oral surgery to drill or cut into the upper or lower jaw and may be used to prepare bone to insert a wire, pin, or screw....

  9. Evolutionary Dynamics of the Accessory Genome of Listeria monocytogenes

    PubMed Central

    den Bakker, Henk C.; Desjardins, Christopher A.; Griggs, Allison D.; Peters, Joseph E.; Zeng, Qiandong; Young, Sarah K.; Kodira, Chinnappa D.; Yandava, Chandri; Hepburn, Theresa A.; Haas, Brian J.; Birren, Bruce W.; Wiedmann, Martin

    2013-01-01

    Listeria monocytogenes, a foodborne bacterial pathogen, is comprised of four phylogenetic lineages that vary with regard to their serotypes and distribution among sources. In order to characterize lineage-specific genomic diversity within L. monocytogenes, we sequenced the genomes of eight strains from several lineages and serotypes, and characterized the accessory genome, which was hypothesized to contribute to phenotypic differences across lineages. The eight L. monocytogenes genomes sequenced range in size from 2.85–3.14 Mb, encode 2,822–3,187 genes, and include the first publicly available sequenced representatives of serotypes 1/2c, 3a and 4c. Mapping of the distribution of accessory genes revealed two distinct regions of the L. monocytogenes chromosome: an accessory-rich region in the first 65° adjacent to the origin of replication and a more stable region in the remaining 295°. This pattern of genome organization is distinct from that of related bacteria Staphylococcus aureus and Bacillus cereus. The accessory genome of all lineages is enriched for cell surface-related genes and phosphotransferase systems, and transcriptional regulators, highlighting the selective pressures faced by contemporary strains from their hosts, other microbes, and their environment. Phylogenetic analysis of O-antigen genes and gene clusters predicts that serotype 4 was ancestral in L. monocytogenes and serotype 1/2 associated gene clusters were putatively introduced through horizontal gene transfer in the ancestral population of L. monocytogenes lineage I and II. PMID:23825666

  10. 49 CFR 192.147 - Flanges and flange accessories.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...a) Each flange or flange accessory (other than cast iron) must meet the minimum requirements of ASME/ANSI B16.5, MSS SP-44, or the equivalent. (b) Each flange assembly must be able to withstand the maximum pressure at which the...

  11. Oncocytic carcinoma of the accessory lobe of the parotid gland.

    PubMed

    Colella, Giuseppe; Apicella, Adolfo; Bove, Pierfrancesco; Rossiello, Luigi; Trodella, Michele; Rossiello, Raffaele

    2010-11-01

    Oncocytic carcinoma is a rare tumor of the parotid gland. An additional case, characterized by an exceptional localization in the accessory lobe of the parotid gland, never reported to date in the literature, is described. The clinical and histologic difficulties in relationship to the diagnosis of a midcheek mass consisting of an unusual tumor are emphasized. PMID:21119478

  12. Ductal Cysts of the Accessory Lacrimal Glands: CT Findings

    Microsoft Academic Search

    Nabil J. Khoury; Maurice C. Haddad; Ayman N. Tawil; Riad N. Ma' luf

    Summary: Benign ductal cysts of the accessory lacrimal glands are uncommon lesions of the orbit, arising from the glands of Wolfring and Krause. We report two patients with histopathologically proved cysts in whom CT scans revealed well-circumscribed extraconal cystic lesions ad- jacent to the globe, involving both eyelids. Radiologists should be aware of these rare lesions so as to include

  13. Local invertible analytic solution of a functional differential equation with deviating arguments depending on the state derivative

    NASA Astrophysics Data System (ADS)

    Si, Jianguo; Ma, Minghuan

    2007-03-01

    This paper is concerned with a functional differential equation of the formx'(z)=1/x(az+bx'(z)) with the distinctive feature that the argument of the unknown function depends on the state derivative, where a,b are two complex numbers. By reducing the equation with the Schroder transformation to another functional differential equation with proportional delay, we give existence of its local invertible analytic solutions. We discuss not only that the constant [alpha] given in Schroder transformation at resonance, i.e., at a root of the unity, but also those [alpha] near resonance (near a root of the unity) under the Brjuno condition.

  14. Differentiation of nonnegative measurable function Choquet integral over real fuzzy measure space and its application to financial option trading model

    Microsoft Academic Search

    Toshihiro Kaino; Kaoru Hirota

    1999-01-01

    Fuzzy measure shift differentiation of the Choquet integral for a nonnegative measurable function taken with respect to a fuzzy measure over a real fuzzy measure space is proposed. It is applied to financial engineering. First, a real interval limited Choquet integral for a nonnegative measurable function taken with respect to a fuzzy measure over a real fuzzy measure space is

  15. Math 3333: A Continuous But Nowhere Differentiable Function Consider a sequence of partial sums of the form sn(x) =

    E-print Network

    Glowinski, Roland

    inequality comes from the mean value theorem: Given a = b there is a c between a and b such that cos(a) - cosMath 3333: A Continuous But Nowhere Differentiable Function Consider a sequence of partial sums that N > 3 2 + 1. From the theorem given above it's easy to see W defines a continuous function on R

  16. Convergent expansions for solutions of linear ordinary differential equations having a simple pole, with an application to associated Legendre functions

    Microsoft Academic Search

    T. M. Dunster

    Second-order linear ordinary differential equations with a large parameter u are examined. Asymptotic expansions involving modified Bessel functions are applicable for the case where the coefficient function of the large parameter has a simple pole. In this paper, we examine such equations in the complex plane, and convert the asymptotic expansions into uniformly convergent series, where u appears in an

  17. Exam #3, Math 309, Dr. M. Bohner, Dec 11, 2002. Name: A function f : I R is called differentiable at x0 I provided lim .

    E-print Network

    Bohner, Martin

    satisfies . Rolle's Theorem states that . The two main mean value results on differentiable functions readExam #3, Math 309, Dr. M. Bohner, Dec 11, 2002. Name: A function f : I R is called differentiable at x0 I provided lim . The basic rules for differentiation (provided all occuring derivatives exist

  18. Differentiations and Functional State of Osteogenic Cells in Conditions of Microgravity

    NASA Astrophysics Data System (ADS)

    Onishchenko, Ganna; Rodionova, Natalia; Markevich, Ganna; Markevich, Ganna

    The space flight factors (space radiation, magnetic fields etc.) affect considerably the state of bone tissue, leading to the development of osteoporosis and osteopenia in the bone skeleton. Many aspects of reactions of bone tissue cells still remain unclear until now. With the use of electron microscopy and autoradiography with 3H-thymidine we studied the samples gathered from the femoral bone epiphyses and metaphyses of rats flown on board American Spacelab -2 and in experiments with modeling of microgravity ("tail suspension" method). In our work the main attention is focused on studying the ultrastructure and metabolism of osteogenetic cells. The degree of differentiation and functional state are evaluated according to the degree of development of organelles for specific biosynthesis: rough endoplasmic reticulum (RER), Golgy complex (GC), as well as the state of mitochondria and cell nucleus. As compared with a control, the population of osteogenetic cells from zones of bone reconstruction shows a decrease in the number of functionally active forms. We can judge of this from the reduction volume of RER, GC, mitochondria in osteoblasts. RER loses architectonics typical for osteoblasts and, as against the control, is represented by short narrow canaliculi distributed throughout the cy-toplasm; some canals disintegrate. GC is slightly pronounced, mitochondria become smaller in size and acquire an optically dark matrix. These phenomena are supposed to be associated with the desorganization of microtubules and microfilaments in the cells under microgravity condi-tions. The number of degrading and apoptotic cells increases in the population of osteoblasts. The dynamics of labeled cells following various intervals after 3H-thymidine injection testifies to a delay in the rates of osteoblasts' differentiation and their transformation to osteocytes in the experiment animals. A lower 3H-glycine uptake by the osteogenic cells and bone matrix as compared with a control is indicative of a decrease of the osteoplastic process under hypokinesia and modeling microgravity. We concluded that microgravity results in low differentiations and reduction specific functions of osteogenic cells.

  19. Differential uptake of functionalized polystyrene nanoparticles by human macrophages and a monocytic cell line.

    PubMed

    Lunov, Oleg; Syrovets, Tatiana; Loos, Cornelia; Beil, Johanna; Delacher, Michael; Tron, Kyrylo; Nienhaus, G Ulrich; Musyanovych, Anna; Mailänder, Volker; Landfester, Katharina; Simmet, Thomas

    2011-03-22

    Tumor cell lines are often used as models for the study of nanoparticle-cell interactions. Here we demonstrate that carboxy (PS-COOH) and amino functionalized (PS-NH2) polystyrene nanoparticles of ?100 nm in diameter are internalized by human macrophages, by undifferentiated and by PMA-differentiated monocytic THP-1 cells via diverse mechanisms. The uptake mechanisms also differed for all cell types and particles when analyzed either in buffer or in medium containing human serum. Macrophages internalized ?4 times more PS-COOH than THP-1 cells, when analyzed in serum-containing medium. By contrast, in either medium, THP-1 cells internalized PS-NH2 more rapidly than macrophages. Using pharmacological and antisense in vitro knockdown approaches, we showed that, in the presence of serum, the specific interaction between the CD64 receptor and the particles determines the macrophage uptake of particles by phagocytosis, whereas particle internalization in THP-1 cells occurred via dynamin II-dependent endocytosis. PMA-differentiated THP-1 cells differed in their uptake mechanism from macrophages and undifferentiated THP-1 cells by internalizing the particles via macropinocytosis. In line with our in vitro data, more intravenously applied PS-COOH particles accumulated in the liver, where macrophages of the reticuloendothelial system reside. By contrast, PS-NH2 particles were preferentially targeted to tumor xenografts grown on the chorioallantoic membrane of fertilized chicken eggs. Our data show that the amount of internalized nanoparticles, the uptake kinetics, and its mechanism may differ considerably between primary cells and a related tumor cell line, whether differentiated or not, and that particle uptake by these cells is critically dependent on particle opsonization by serum proteins. PMID:21344890

  20. Immune evasion activities of accessory proteins Vpu, Nef and Vif are conserved in acute and chronic HIV-1 infection.

    PubMed

    Mlcochova, Petra; Apolonia, Luis; Kluge, Silvia F; Sridharan, Aishwarya; Kirchhoff, Frank; Malim, Michael H; Sauter, Daniel; Gupta, Ravindra K

    2015-08-01

    Heterosexual HIV-1 transmission has been identified as a genetic bottleneck and a single transmitted/founder (T/F) variant with reduced sensitivity to type I interferon initiates productive infection in most cases. We hypothesized that particularly active accessory protein(s) may confer T/F viruses with a selective advantage in establishing HIV infection. Thus, we tested vpu, vif and nef alleles from six T/F and six chronic (CC) viruses in assays for 9 immune evasion activities involving the counteraction of interferon-stimulated genes and modulation of ligands known to activate innate immune cells. All functions were highly conserved with no significant differences between T/F and CC viruses, suggesting that these accessory protein functions are important throughout the course of infection. PMID:25827531

  1. Functional plasticity of the N-methyl-d-aspartate receptor in differentiating human erythroid precursor cells

    PubMed Central

    Hänggi, Pascal; Telezhkin, Vsevolod; Kemp, Paul J.; Schmugge, Markus; Gassmann, Max; Goede, Jeroen S.; Speer, Oliver

    2015-01-01

    Calcium signaling is essential to support erythroid proliferation and differentiation. Precise control of the intracellular Ca2+ levels in erythroid precursor cells (EPCs) is afforded by coordinated expression and function of several cation channels, including the recently identified N-methyl-d-aspartate receptor (NMDAR). Here, we characterized the changes in Ca2+ uptake and electric currents mediated by the NMDARs occurring during EPC differentiation using flow cytometry and patch clamp. During erythropoietic maturation, subunit composition and properties of the receptor changed; in proerythroblasts and basophilic erythroblasts, fast deactivating currents with high amplitudes were mediated by the GluN2A subunit-dominated receptors, while at the polychromatic and orthochromatic erythroblast stages, the GluN2C subunit was getting more abundant, overriding the expression of GluN2A. At these stages, the currents mediated by the NMDARs carried the features characteristic of the GluN2C-containing receptors, such as prolonged decay time and lower conductance. Kinetics of this switch in NMDAR properties and abundance varied markedly from donor to donor. Despite this variability, NMDARs were essential for survival of EPCs in any subject tested. Our findings indicate that NMDARs have a dual role during erythropoiesis, supporting survival of polychromatic erythroblasts and contributing to the Ca2+ homeostasis from the orthochromatic erythroblast stage to circulating red blood cells. PMID:25788577

  2. Acceleration of screened-exchange density-functional calculations with approximate differential overlap

    NASA Astrophysics Data System (ADS)

    Moussa, Jonathan; Schultz, Peter

    2014-03-01

    We implement the Heyd-Scuseria-Ernzerhof (HSE) screened-exchange density functional in the SEQQUEST electronic structure code. HSE calculations are accelerated by approximating differential overlap in the Fock exchange based on an atomic-orbital partitioning scheme. All one-center and two-center exchange integrals are calculated. A subset of three-center exchange integrals are calculated for one-center Fock exchange matrix elements and for exchange mediated by one-center density matrix elements. Four-center exchange integrals are not calculated. We test the validity of this approximation by examining the number and magnitude of these different classes of exchange integrals. Basis set and pseudopotential errors in HSE calculations are benchmarked on atoms. Differential overlap approximation errors are benchmarked on small molecules. Sandia National Labs is a multi-program laboratory managed and operated by Sandia Corp., a wholly owned subsidiary of Lockheed Martin Corp., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  3. Manganese superoxide dismutase is required to maintain osteoclast differentiation and function under static force.

    PubMed

    Guo, Tao; Zhang, Liqiang; Konermann, Anna; Zhou, Hong; Jin, Fang; Liu, Wenjia

    2015-01-01

    Bone homeostasis is maintained by the balance of osteoblasts (OBs) and osteoclasts (OCs). Increased activity of OCs not only contributes to pathological bone resorption, such as osteoporosis and periodontitis, but also is responsible for physiological conditions like orthodontic tooth movement (OTM). However, the detailed mechanism by which orthodontic force promotes the formation of OCs is still poorly understood. In this study, we confirmed that static force promoted the differentiation of human cord monocytes (HMNCs) into OCs depending on loading time and magnitude. Protein expression profiles among HMNCs, HMNCs subjected to static force and mature OCs were established via 2-DE and MALDI-TOF-MS analyses. Total respective protein spot numbers of 549 ± 13, 612 ± 19 and 634 ± 16 were detected in each of the gels by image analysis. The five proteins identified were plasminogen activator inhibitor 2 (PAI-2, Spot 1), peroxiredoxin-6 (PRD-6, Spot 3), manganese superoxide dismutase (SOD2, Spot 6), Rho GDP-dissociation inhibitor 2 (Rho-GDI2, Spot 11) and L-lactate dehydrogenase B chain (L-LDH, Spot 15). More importantly, we revealed that SOD2 was required to maintain monocyte differentiation into functional OCs and may become a potential target for regulating the efficiency of OTM in the future. PMID:25619900

  4. Functional plasticity of the N-methyl-d-aspartate receptor in differentiating human erythroid precursor cells.

    PubMed

    Hänggi, Pascal; Telezhkin, Vsevolod; Kemp, Paul J; Schmugge, Markus; Gassmann, Max; Goede, Jeroen S; Speer, Oliver; Bogdanova, Anna

    2015-06-15

    Calcium signaling is essential to support erythroid proliferation and differentiation. Precise control of the intracellular Ca(2+) levels in erythroid precursor cells (EPCs) is afforded by coordinated expression and function of several cation channels, including the recently identified N-methyl-d-aspartate receptor (NMDAR). Here, we characterized the changes in Ca(2+) uptake and electric currents mediated by the NMDARs occurring during EPC differentiation using flow cytometry and patch clamp. During erythropoietic maturation, subunit composition and properties of the receptor changed; in proerythroblasts and basophilic erythroblasts, fast deactivating currents with high amplitudes were mediated by the GluN2A subunit-dominated receptors, while at the polychromatic and orthochromatic erythroblast stages, the GluN2C subunit was getting more abundant, overriding the expression of GluN2A. At these stages, the currents mediated by the NMDARs carried the features characteristic of the GluN2C-containing receptors, such as prolonged decay time and lower conductance. Kinetics of this switch in NMDAR properties and abundance varied markedly from donor to donor. Despite this variability, NMDARs were essential for survival of EPCs in any subject tested. Our findings indicate that NMDARs have a dual role during erythropoiesis, supporting survival of polychromatic erythroblasts and contributing to the Ca(2+) homeostasis from the orthochromatic erythroblast stage to circulating red blood cells. PMID:25788577

  5. Manganese superoxide dismutase is required to maintain osteoclast differentiation and function under static force

    PubMed Central

    Guo, Tao; Zhang, Liqiang; Konermann, Anna; Zhou, Hong; Jin, Fang; Liu, Wenjia

    2015-01-01

    Bone homeostasis is maintained by the balance of osteoblasts (OBs) and osteoclasts (OCs). Increased activity of OCs not only contributes to pathological bone resorption, such as osteoporosis and periodontitis, but also is responsible for physiological conditions like orthodontic tooth movement (OTM). However, the detailed mechanism by which orthodontic force promotes the formation of OCs is still poorly understood. In this study, we confirmed that static force promoted the differentiation of human cord monocytes (HMNCs) into OCs depending on loading time and magnitude. Protein expression profiles among HMNCs, HMNCs subjected to static force and mature OCs were established via 2-DE and MALDI-TOF-MS analyses. Total respective protein spot numbers of 549 ± 13, 612 ± 19 and 634 ± 16 were detected in each of the gels by image analysis. The five proteins identified were plasminogen activator inhibitor 2 (PAI-2, Spot 1), peroxiredoxin-6 (PRD-6, Spot 3), manganese superoxide dismutase (SOD2, Spot 6), Rho GDP-dissociation inhibitor 2 (Rho-GDI2, Spot 11) and L-lactate dehydrogenase B chain (L-LDH, Spot 15). More importantly, we revealed that SOD2 was required to maintain monocyte differentiation into functional OCs and may become a potential target for regulating the efficiency of OTM in the future. PMID:25619900

  6. Comparing Two Intestinal Porcine Epithelial Cell Lines (IPECs): Morphological Differentiation, Function and Metabolism

    PubMed Central

    Nossol, Constanze; Barta-Böszörményi, Anicò; Kahlert, Stefan; Zuschratter, Werner; Faber-Zuschratter, Heidi; Reinhardt, Nicole; Ponsuksili, Siriluk; Wimmers, Klaus; Diesing, Anne-Kathrin; Rothkötter, Hermann-Josef

    2015-01-01

    The pig shows genetical and physiological resemblance to human, which predestines it as an experimental animal model especially for mucosal physiology. Therefore, the intestinal epithelial cell lines 1 and J2 (IPEC-1, IPEC-J2) - spontaneously immortalised cell lines from the porcine intestine - are important tools for studying intestinal function. A microarray (GeneChip Porcine Genome Array) was performed to compare the genome wide gene expression of IPECs. Different significantly up-regulated pathways were identified, like “lysosome”, “pathways in cancer”, “regulation of actin cytoskeleton” and “oxidative phosphorylation” in IPEC-J2 in comparison to IPEC-1. On the other hand, “spliceosome”, “ribosome”, “RNA-degradation” and “tight junction” are significantly down-regulated pathways in IPEC-J2 in comparison to IPEC-1. Examined pathways were followed up by functional analyses. ATP-, oxygen, glucose and lactate-measurement provide evidence for up-regulation of oxidative phosphorylation in IPEC-J2. These cells seem to be more active in their metabolism than IPEC-1 cells due to a significant higher ATP-content as well as a higher O2- and glucose-consumption. The down-regulated pathway “ribosome” was followed up by measurement of RNA- and protein content. In summary, IPEC-J2 is a morphologically and functionally more differentiated cell line in comparison to IPEC-1. In addition, IPEC-J2 cells are a preferential tool for in vitro studies with the focus on metabolism. PMID:26147118

  7. Stimulation of proliferation, differentiation, and function of human cells by primate interleukin 3

    SciTech Connect

    Lopez, A.F.; To, L.B.; Yang, Y.C.; Gamble, J.R.; Shannon, M.F.; Burns, G.F.; Dyson, P.G.; Juttner, C.A.; Clark, S.; Vadas, M.A.

    1987-05-01

    Cloned gibbon interleukin 3 (gIL-3) was found to stimulate the proliferation and differentiation of human bone marrow cells to produce day-14 granulocyte, macrophage, granulocyte-macrophage, and eosinophil colonies in semisolid agar. In the presence of normal human plasma, gIL-3 stimulated megakaryocytes. In methylcellulose cultures, it stimulated erythroid colonies in the presence, but not in the absence, of erythropoietin. When mature human leukocytes were used, gIL-3 stimulated the function of purified mature eosinophils as measured by the capacity to kill /sup 51/Cr-labeled antibody-coated target cells, to produce superoxide anions, and to phagocytize opsonized yeast particles in a manner similar to recombinant human granulocyte-macrophage colony-stimulating factor. In contrast, gIL-3 did not significantly stimulate any of the neutrophil functions tested, whereas human recombinant granulocyte-macrophage colony-stimulating factor was active in these assay. Among cytokines that are active on human hematopoietic cells, gIL-3 thus has a distinct set of functions and may predict the range of actions of the human molecule.

  8. Visualizing digestive organ morphology and function using differential fatty acid metabolism in live zebrafish

    PubMed Central

    Carten, Juliana Debrito; Bradford, Mary Katherine; Farber, Steven Arthur

    2012-01-01

    Lipids are essential for cellular function as sources of fuel, critical signaling molecules and membrane components. Deficiencies in lipid processing and transport underlie many metabolic diseases. To better understand metabolic function as it relates to disease etiology, a whole animal approach is advantageous, one in which multiple organs and cell types can be assessed simultaneously in vivo. Towards this end, we have developed an assay to visualize fatty acid (FA) metabolism in larval zebrafish (Danio rerio). The method utilizes egg yolk liposomes to deliver different chain length FA analogs (BODIPY-FL) to six day-old larvae. Following liposome incubation, larvae accumulate the analogs throughout their digestive organs, providing a comprehensive readout of organ structure and physiology. Using this assay we have observed that different chain length FAs are differentially transported and metabolized by the larval digestive system. We show that this assay can also reveal structural and metabolic defects in digestive mutants. Because this labeling technique can be used to investigate digestive organ morphology and function, we foresee its application in diverse studies of organ development and physiology. PMID:21968100

  9. Comparing Two Intestinal Porcine Epithelial Cell Lines (IPECs): Morphological Differentiation, Function and Metabolism.

    PubMed

    Nossol, Constanze; Barta-Böszörményi, Anicò; Kahlert, Stefan; Zuschratter, Werner; Faber-Zuschratter, Heidi; Reinhardt, Nicole; Ponsuksili, Siriluk; Wimmers, Klaus; Diesing, Anne-Kathrin; Rothkötter, Hermann-Josef

    2015-01-01

    The pig shows genetical and physiological resemblance to human, which predestines it as an experimental animal model especially for mucosal physiology. Therefore, the intestinal epithelial cell lines 1 and J2 (IPEC-1, IPEC-J2) - spontaneously immortalised cell lines from the porcine intestine - are important tools for studying intestinal function. A microarray (GeneChip Porcine Genome Array) was performed to compare the genome wide gene expression of IPECs. Different significantly up-regulated pathways were identified, like "lysosome", "pathways in cancer", "regulation of actin cytoskeleton" and "oxidative phosphorylation" in IPEC-J2 in comparison to IPEC-1. On the other hand, "spliceosome", "ribosome", "RNA-degradation" and "tight junction" are significantly down-regulated pathways in IPEC-J2 in comparison to IPEC-1. Examined pathways were followed up by functional analyses. ATP-, oxygen, glucose and lactate-measurement provide evidence for up-regulation of oxidative phosphorylation in IPEC-J2. These cells seem to be more active in their metabolism than IPEC-1 cells due to a significant higher ATP-content as well as a higher O2- and glucose-consumption. The down-regulated pathway "ribosome" was followed up by measurement of RNA- and protein content. In summary, IPEC-J2 is a morphologically and functionally more differentiated cell line in comparison to IPEC-1. In addition, IPEC-J2 cells are a preferential tool for in vitro studies with the focus on metabolism. PMID:26147118

  10. Differential Selection within the Drosophila Retinal Determination Network and Evidence for Functional Divergence between Paralog Pairs

    PubMed Central

    Datta, Rhea R.; Cruickshank, Tami; Kumar, Justin P.

    2011-01-01

    The retinal determination (RD) network in Drosophila comprises fourteen known nuclear proteins that include DNA binding proteins, transcriptional co-activators, kinases and phosphatases. The composition of the network varies considerably throughout the animal kingdom, with the network in several basal insects having fewer members and with vertebrates having potentially significantly higher numbers of retinal determination genes. One important contributing factor for the variation in gene number within the network is gene duplication. For example, ten members of the RD network in Drosophila are derived from duplication events. Here we present an analysis of the coding regions of the five pairs of duplicate genes from within the retinal determination network of several different Drosophila species. We demonstrate that there is differential selection across the coding regions of all RD genes. Additionally, some of the most significant differences in ratios of non-silent to silent site substitutions (dN/dS) between paralog pairs are found within regions that have no ascribed function. Previous structure/function analyses of several duplicate genes have identified areas within one gene that contain novel activities when compared to its paralog. The evolutionary analysis presented here identifies these same areas in the paralogs as being under high levels of relaxed selection. We suggest that sequence divergence between paralogs and selection signatures can be used as a reasonable predictor of functional changes in rapidly evolving motifs. PMID:21210943

  11. Activated NKT cells imprint NK-cell differentiation, functionality and education.

    PubMed

    Riese, Peggy; Trittel, Stephanie; May, Tobias; Cicin-Sain, Luka; Chambers, Benedict J; Guzmán, Carlos A

    2015-06-01

    NK cells represent a vital component of the innate immune system. The recent discoveries demonstrating that the functionality of NK cells depends on their differentiation and education status underscore their potential as targets for immune intervention. However, to exploit their full potential, a detailed understanding of the cellular interactions involved in these processes is required. In this regard, the cross-talk between NKT cells and NK cells needs to be better understood. Our results provide strong evidence for NKT cell-induced effects on key biological features of NK cells. NKT-cell activation results in the generation of highly active CD27(high) NK cells with improved functionality. In this context, degranulation activity and IFN? production were mainly detected in the educated subset. In a mCMV infection model, we also demonstrated that NKT-cell stimulation induced the generation of highly functional educated and uneducated NK cells, crucial players in viral control. Thus, our findings reveal new fundamental aspects of the NKT-NK cell axis that provide important hints for the manipulation of NK cells in clinical settings. PMID:25808315

  12. Structural Insights into Functional Overlapping and Differentiation among Myosin V Motors*

    PubMed Central

    Nascimento, Andrey F. Z.; Trindade, Daniel M.; Tonoli, Celisa C. C.; de Giuseppe, Priscila O.; Assis, Leandro H. P.; Honorato, Rodrigo V.; de Oliveira, Paulo S. L.; Mahajan, Pravin; Burgess-Brown, Nicola A.; von Delft, Frank; Larson, Roy E.; Murakami, Mario T.

    2013-01-01

    Myosin V (MyoV) motors have been implicated in the intracellular transport of diverse cargoes including vesicles, organelles, RNA-protein complexes, and regulatory proteins. Here, we have solved the cargo-binding domain (CBD) structures of the three human MyoV paralogs (Va, Vb, and Vc), revealing subtle structural changes that drive functional differentiation and a novel redox mechanism controlling the CBD dimerization process, which is unique for the MyoVc subclass. Moreover, the cargo- and motor-binding sites were structurally assigned, indicating the conservation of residues involved in the recognition of adaptors for peroxisome transport and providing high resolution insights into motor domain inhibition by CBD. These results contribute to understanding the structural requirements for cargo transport, autoinhibition, and regulatory mechanisms in myosin V motors. PMID:24097982

  13. Differential item functioning by sex and race in the Hogan Personality Inventory.

    PubMed

    Sheppard, Richard; Han, Kyunghee; Colarelli, Stephen M; Dai, Guangdong; King, Daniel W

    2006-12-01

    The authors examined measurement bias in the Hogan Personality Inventory by investigating differential item functioning (DIF) across sex and two racial groups (Caucasian and Black). The sample consisted of 1,579 Caucasians (1,023 men, 556 women) and 523 Blacks (321 men, 202 women) who were applying for entry-level, unskilled jobs in factories. Although the group mean differences were trivial, more than a third of the items showed DIF by sex (38.4%) and by race (37.3%). A content analysis of potentially biased items indicated that the themes of items displaying DIF were slightly more cohesive for sex than for race. The authors discuss possible explanations for differing clustering tendencies of items displaying DIF and some practical and theoretical implications of DIF in the development and interpretation of personality inventories. PMID:17050914

  14. Assessing T lymphocyte function and differentiation by genetically encoded reporter systems.

    PubMed

    Hoekstra, Mirjam E; Dijkgraaf, Feline E; Schumacher, Ton N; Rohr, Jan C

    2015-07-01

    Upon infection, antigen-specific T lymphocytes become activated, proliferate, differentiate, and acquire various effector functions. Much of our understanding of the molecular mechanisms underlying these processes derives from studies leveraging gene deletion, RNAi, and overexpression approaches. However, these perturbations do not inform on the regulation of gene activity under physiological conditions. Genetic reporter systems that couple biological events to detectable output signals are capable of providing this information. Here, we review the reporter approaches being currently used to investigate various aspects of T cell behavior, and discuss advantages and disadvantages inherent to different designs. We outline emerging applications based on recent advances in other fields, and highlight the potential of synthetic biology and genome engineering to address open questions in the field. PMID:26072285

  15. Differential forms in spaces without a norm. A theorem on the uniqueness of Boltzmann's H-function

    NASA Astrophysics Data System (ADS)

    Vedenyapin, V. V.

    1988-02-01

    CONTENTS Introduction § 1. Stokes' formula and differentiation in spaces without a norm § 2. Extensive functionals invariant under free motion § 3. The Kac-Moran conjecture and the McKean-Waldmann theorem. Generalization of the theorem on summator invariants § 4. A theorem on the uniqueness of Boltzmann's H-function § 5. Discrete models of the Boltzmann equation: a priori estimates and existence theorems § 6. Analogues of Boltzmann's H-function References

  16. The B. subtilis Accessory Helicase PcrA Facilitates DNA Replication through Transcription Units.

    PubMed

    Merrikh, Christopher N; Brewer, Bonita J; Merrikh, Houra

    2015-06-01

    In bacteria the concurrence of DNA replication and transcription leads to potentially deleterious encounters between the two machineries, which can occur in either the head-on (lagging strand genes) or co-directional (leading strand genes) orientations. These conflicts lead to replication fork stalling and can destabilize the genome. Both eukaryotic and prokaryotic cells possess resolution factors that reduce the severity of these encounters. Though Escherichia coli accessory helicases have been implicated in the mitigation of head-on conflicts, direct evidence of these proteins mitigating co-directional conflicts is lacking. Furthermore, the endogenous chromosomal regions where these helicases act, and the mechanism of recruitment, have not been identified. We show that the essential Bacillus subtilis accessory helicase PcrA aids replication progression through protein coding genes of both head-on and co-directional orientations, as well as rRNA and tRNA genes. ChIP-Seq experiments show that co-directional conflicts at highly transcribed rRNA, tRNA, and head-on protein coding genes are major targets of PcrA activity on the chromosome. Partial depletion of PcrA renders cells extremely sensitive to head-on conflicts, linking the essential function of PcrA to conflict resolution. Furthermore, ablating PcrA's ATPase/helicase activity simultaneously increases its association with conflict regions, while incapacitating its ability to mitigate conflicts, and leads to cell death. In contrast, disruption of PcrA's C-terminal RNA polymerase interaction domain does not impact its ability to mitigate conflicts between replication and transcription, its association with conflict regions, or cell survival. Altogether, this work establishes PcrA as an essential factor involved in mitigating transcription-replication conflicts and identifies chromosomal regions where it routinely acts. As both conflicts and accessory helicases are found in all domains of life, these results are broadly relevant. PMID:26070154

  17. The B. subtilis Accessory Helicase PcrA Facilitates DNA Replication through Transcription Units

    PubMed Central

    Merrikh, Christopher N.; Brewer, Bonita J.; Merrikh, Houra

    2015-01-01

    In bacteria the concurrence of DNA replication and transcription leads to potentially deleterious encounters between the two machineries, which can occur in either the head-on (lagging strand genes) or co-directional (leading strand genes) orientations. These conflicts lead to replication fork stalling and can destabilize the genome. Both eukaryotic and prokaryotic cells possess resolution factors that reduce the severity of these encounters. Though Escherichia coli accessory helicases have been implicated in the mitigation of head-on conflicts, direct evidence of these proteins mitigating co-directional conflicts is lacking. Furthermore, the endogenous chromosomal regions where these helicases act, and the mechanism of recruitment, have not been identified. We show that the essential Bacillus subtilis accessory helicase PcrA aids replication progression through protein coding genes of both head-on and co-directional orientations, as well as rRNA and tRNA genes. ChIP-Seq experiments show that co-directional conflicts at highly transcribed rRNA, tRNA, and head-on protein coding genes are major targets of PcrA activity on the chromosome. Partial depletion of PcrA renders cells extremely sensitive to head-on conflicts, linking the essential function of PcrA to conflict resolution. Furthermore, ablating PcrA’s ATPase/helicase activity simultaneously increases its association with conflict regions, while incapacitating its ability to mitigate conflicts, and leads to cell death. In contrast, disruption of PcrA’s C-terminal RNA polymerase interaction domain does not impact its ability to mitigate conflicts between replication and transcription, its association with conflict regions, or cell survival. Altogether, this work establishes PcrA as an essential factor involved in mitigating transcription-replication conflicts and identifies chromosomal regions where it routinely acts. As both conflicts and accessory helicases are found in all domains of life, these results are broadly relevant. PMID:26070154

  18. Burkholderia pseudomallei sequencing identifies genomic clades with distinct recombination, accessory, and epigenetic profiles

    PubMed Central

    Nandi, Tannistha; Holden, Matthew T.G.; Didelot, Xavier; Mehershahi, Kurosh; Boddey, Justin A.; Beacham, Ifor; Peak, Ian; Harting, John; Baybayan, Primo; Guo, Yan; Wang, Susana; How, Lee Chee; Sim, Bernice; Essex-Lopresti, Angela; Sarkar-Tyson, Mitali; Nelson, Michelle; Smither, Sophie; Ong, Catherine; Aw, Lay Tin; Hoon, Chua Hui; Michell, Stephen; Studholme, David J.; Titball, Richard; Chen, Swaine L.; Parkhill, Julian

    2015-01-01

    Burkholderia pseudomallei (Bp) is the causative agent of the infectious disease melioidosis. To investigate population diversity, recombination, and horizontal gene transfer in closely related Bp isolates, we performed whole-genome sequencing (WGS) on 106 clinical, animal, and environmental strains from a restricted Asian locale. Whole-genome phylogenies resolved multiple genomic clades of Bp, largely congruent with multilocus sequence typing (MLST). We discovered widespread recombination in the Bp core genome, involving hundreds of regions associated with multiple haplotypes. Highly recombinant regions exhibited functional enrichments that may contribute to virulence. We observed clade-specific patterns of recombination and accessory gene exchange, and provide evidence that this is likely due to ongoing recombination between clade members. Reciprocally, interclade exchanges were rarely observed, suggesting mechanisms restricting gene flow between clades. Interrogation of accessory elements revealed that each clade harbored a distinct complement of restriction-modification (RM) systems, predicted to cause clade-specific patterns of DNA methylation. Using methylome sequencing, we confirmed that representative strains from separate clades indeed exhibit distinct methylation profiles. Finally, using an E. coli system, we demonstrate that Bp RM systems can inhibit uptake of non-self DNA. Our data suggest that RM systems borne on mobile elements, besides preventing foreign DNA invasion, may also contribute to limiting exchanges of genetic material between individuals of the same species. Genomic clades may thus represent functional units of genetic isolation in Bp, modulating intraspecies genetic diversity. PMID:25236617

  19. Couple of the Variational Iteration Method and Fractional-Order Legendre Functions Method for Fractional Differential Equations

    PubMed Central

    Song, Junqiang; Leng, Hongze; Lu, Fengshun

    2014-01-01

    We present a new numerical method to get the approximate solutions of fractional differential equations. A new operational matrix of integration for fractional-order Legendre functions (FLFs) is first derived. Then a modified variational iteration formula which can avoid “noise terms” is constructed. Finally a numerical method based on variational iteration method (VIM) and FLFs is developed for fractional differential equations (FDEs). Block-pulse functions (BPFs) are used to calculate the FLFs coefficient matrices of the nonlinear terms. Five examples are discussed to demonstrate the validity and applicability of the technique. PMID:24511303

  20. An extracytoplasmic function sigma factor, ?(25), differentially regulates avermectin and oligomycin biosynthesis in Streptomyces avermitilis.

    PubMed

    Luo, Shuai; Sun, Di; Zhu, Jianya; Chen, Zhi; Wen, Ying; Li, Jilun

    2014-08-01

    ?(25) is an extracytoplasmic function (ECF) ? factor in the bacterium Streptomyces avermitilis that plays a differential regulatory role in avermectin and oligomycin biosynthesis. Gene deletion, complementation, and overexpression experiments showed that ?(25) inhibited avermectin production but promoted oligomycin production. ?(25) indirectly inhibited avermectin production by affecting the transcription of the pathway-specific activator gene aveR, whereas it directly activated oligomycin production by initiating transcription of the pathway-specific activator gene olmRI. The divergently transcribed genes smrAB are located upstream of sig25 and encode a putative two-component system (TCS). ?(25) was found to initiate its own transcription, and its expression was directly activated by SmrA. The precise SmrA-binding sites in the region upstream of sig25 were determined by DNase I footprinting assays and identified two direct repeat sequences CTGTGA-n5-CTGTGA, suggesting that SmrA regulates sig25 transcription by binding to these direct repeats. The deletion of smrAB had the similar effect on avermectin and oligomycin A production to the deletion of sig25, indicating that ?(25) and SmrAB function similarly in the regulation of antibiotic production. These findings helpfully clarify the regulation of antibiotic biosynthesis by an ECF ? factor-TCS signal transduction system in S. avermitilis. PMID:24811406