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Sample records for cells direct evidence

  1. Enantiopure titanocene complexes - direct evidence for paraptosis in cancer cells.

    Science.gov (United States)

    Cini, Melchior; Williams, Huw; Fay, Mike W; Searle, Mark S; Woodward, Simon; Bradshaw, Tracey D

    2016-03-16

    Tolerated by normal tissues, anti-cancer therapies based on titanium compounds are limited by low efficacy/selectivity and lack of understanding of their mode(s) of action. In vitro antitumour activity and mode of cell death incurred by enantiopure TiCl2{η-C5H4CHEt(2-MeOPh)}2 (abbreviated Cp(R)2TiCl2) has been investigated. The in vitro anti-tumour activity of Cp(R)2TiCl2 is selective for cancer cells; in clonogenic assays, (S,S)-Cp(R)2TiCl2 was twice as effective at inhibiting colony formation than other stereoisomers after 24 h exposure. HPLC, MS and NMR techniques determined hydrolysis of Cp(R)2TiCl2; data strongly correlate with soluble [Cp(R)2Ti(OH)(OH2)](+) being the biological trigger. Treatment of cells with Cp(R)2TiCl2 provoked extensive cytoplasmic vacuolization, endoplasmic reticulum (ER) swelling and activation of MAPKinase signal transduction, consistent with ligand-induced paraptosis, type III cell death, which is morphologically distinct from, and independent of apoptosis. Indeed, distinct from cisplatin, Cp(R)2TiCl2 failed to perturb cell cycle dynamics, induce γH2AX foci or evoke apoptosis in MDA-MB-468 and HCT-116 cells. PMID:26806372

  2. Multiple origins of spontaneously arising micronuclei in HeLa cells: Direct evidence from long-term live cell imaging

    International Nuclear Information System (INIS)

    Although micronuclei (MNi) are extensively used to evaluate genotoxic effects and chromosome instability, the most basic issue regarding their origins has not been completely addressed due to limitations of traditional methods. Recently, long-term live cell imaging was developed to monitor the dynamics of single cell in a real-time and high-throughput manner. In the present study, this state-of-the-art technique was employed to examine spontaneous micronucleus (MN) formation in untreated HeLa cells. We demonstrate that spontaneous MNi are derived from incorrectly aligned chromosomes in metaphase (displaced chromosomes, DCs), lagging chromosomes (LCs) and broken chromosome bridges (CBs) in later mitotic stages, but not nuclear buds in S phase. However, most of bipolar mitoses with DCs (91.29%), LCs (73.11%) and broken CBs (88.93%) did not give rise to MNi. Our data also show directly, for the first time, that MNi could originate spontaneously from (1) MNi already presented in the mother cells; (2) nuclear fragments that appeared during mitosis with CB; and (3) chromosomes being extruded into a minicell which fused with one of the daughter cells later. Quantitatively, most of MNi originated from LCs (63.66%), DCs (10.97%) and broken CBs (9.25%). Taken together, these direct evidences show that there are multiple origins for spontaneously arising MNi in HeLa cells and each mechanism contributes to overall MN formation to different extents

  3. Proton Beam Therapy for Non-Small Cell Lung Cancer: Current Clinical Evidence and Future Directions

    Energy Technology Data Exchange (ETDEWEB)

    Berman, Abigail T., E-mail: abigail.berman@uphs.upenn.edu [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104 (United States); James, Sara St.; Rengan, Ramesh [Department of Radiation Oncology, University of Washington Medical Center, Seattle, WA 98195 (United States)

    2015-07-02

    Lung cancer is the leading cancer cause of death in the United States. Radiotherapy is an essential component of the definitive treatment of early-stage and locally-advanced lung cancer, and the palliative treatment of metastatic lung cancer. Proton beam therapy (PBT), through its characteristic Bragg peak, has the potential to decrease the toxicity of radiotherapy, and, subsequently improve the therapeutic ratio. Herein, we provide a primer on the physics of proton beam therapy for lung cancer, present the existing data in early-stage and locally-advanced non-small cell lung cancer (NSCLC), as well as in special situations such as re-irradiation and post-operative radiation therapy. We then present the technical challenges, such as anatomic changes and motion management, and future directions for PBT in lung cancer, including pencil beam scanning.

  4. Proton Beam Therapy for Non-Small Cell Lung Cancer: Current Clinical Evidence and Future Directions

    International Nuclear Information System (INIS)

    Lung cancer is the leading cancer cause of death in the United States. Radiotherapy is an essential component of the definitive treatment of early-stage and locally-advanced lung cancer, and the palliative treatment of metastatic lung cancer. Proton beam therapy (PBT), through its characteristic Bragg peak, has the potential to decrease the toxicity of radiotherapy, and, subsequently improve the therapeutic ratio. Herein, we provide a primer on the physics of proton beam therapy for lung cancer, present the existing data in early-stage and locally-advanced non-small cell lung cancer (NSCLC), as well as in special situations such as re-irradiation and post-operative radiation therapy. We then present the technical challenges, such as anatomic changes and motion management, and future directions for PBT in lung cancer, including pencil beam scanning

  5. Proton Beam Therapy for Non-Small Cell Lung Cancer: Current Clinical Evidence and Future Directions

    Directory of Open Access Journals (Sweden)

    Abigail T. Berman

    2015-07-01

    Full Text Available Lung cancer is the leading cancer cause of death in the United States. Radiotherapy is an essential component of the definitive treatment of early-stage and locally-advanced lung cancer, and the palliative treatment of metastatic lung cancer. Proton beam therapy (PBT, through its characteristic Bragg peak, has the potential to decrease the toxicity of radiotherapy, and, subsequently improve the therapeutic ratio. Herein, we provide a primer on the physics of proton beam therapy for lung cancer, present the existing data in early-stage and locally-advanced non-small cell lung cancer (NSCLC, as well as in special situations such as re-irradiation and post-operative radiation therapy. We then present the technical challenges, such as anatomic changes and motion management, and future directions for PBT in lung cancer, including pencil beam scanning.

  6. Lack of direct evidence for a functional role of voltage-operated calcium channels in juxtaglomerular cells

    OpenAIRE

    Kurtz, Armin; Skott, O.; Chegini, S; Penner, R

    1990-01-01

    In this study we have examined the role of voltage-gated calcium channels in the regulation of calcium in juxtaglomerular cells. Using a combination of patch-clamp and single-cell calcium measurement we obtained evidence neither for voltage-operated calcium currents nor for changes of the intracellular calcium concentration upon acute depolarizations of the cell membrane. Increases of the extracellular concentration of potassium to 80 mmol/l depolarized the juxtaglomerular cells close to the ...

  7. Long-Term Fructose Intake Increases Adipogenic Potential: Evidence of Direct Effects of Fructose on Adipocyte Precursor Cells

    OpenAIRE

    Zubiría, María Guillermina; Alzamendi, Ana; Moreno, Griselda; Rey, María Amanda; Spinedi, Eduardo; Giovambattista, Andrés

    2016-01-01

    We have previously addressed that fructose rich diet (FRD) intake for three weeks increases the adipogenic potential of stromal vascular fraction cells from the retroperitoneal adipose tissue (RPAT). We have now evaluated the effect of prolonged FRD intake (eight weeks) on metabolic parameters, number of adipocyte precursor cells (APCs) and in vitro adipogenic potential from control (CTR) and FRD adult male rats. Additionally, we have examined the direct fructose effects on the adipogenic cap...

  8. Unidirectional fluxes of rhodamine 123 in multidrug-resistant cells: evidence against direct drug extrusion from the plasma membrane.

    OpenAIRE

    Altenberg, G A; Vanoye, C G; Horton, J K; Reuss, L

    1994-01-01

    P-glycoprotein (Pgp), a plasma membrane protein overexpressed in multidrug-resistant tumor cells, is an ATPase thought to actively export cytotoxic drugs. It has been proposed that Pgp transports drugs directly from the lipid bilayer to the external medium ("vacuum cleaner" hypothesis). A possible mechanism for this model is that the Pgp is a flippase--i.e., it catalyzes the translocation of hydrophobic substrates from the inner to the outer leaflet of the cell membrane. Two immediate predict...

  9. Long-Term Fructose Intake Increases Adipogenic Potential: Evidence of Direct Effects of Fructose on Adipocyte Precursor Cells.

    Science.gov (United States)

    Zubiría, María Guillermina; Alzamendi, Ana; Moreno, Griselda; Rey, María Amanda; Spinedi, Eduardo; Giovambattista, Andrés

    2016-01-01

    We have previously addressed that fructose rich diet (FRD) intake for three weeks increases the adipogenic potential of stromal vascular fraction cells from the retroperitoneal adipose tissue (RPAT). We have now evaluated the effect of prolonged FRD intake (eight weeks) on metabolic parameters, number of adipocyte precursor cells (APCs) and in vitro adipogenic potential from control (CTR) and FRD adult male rats. Additionally, we have examined the direct fructose effects on the adipogenic capacity of normal APCs. FRD fed rats had increased plasma levels of insulin, triglyceride and leptin, and RPAT mass and adipocyte size. FACS studies showed higher APCs number and adipogenic potential in FRD RPAT pads; data is supported by high mRNA levels of competency markers: PPARγ2 and Zfp423. Complementary in vitro experiments indicate that fructose-exposed normal APCs displayed an overall increased adipogenic capacity. We conclude that the RPAT mass expansion observed in eight week-FRD fed rats depends on combined accelerated adipogenesis and adipocyte hypertrophy, partially due to a direct effect of fructose on APCs. PMID:27049396

  10. Long-Term Fructose Intake Increases Adipogenic Potential: Evidence of Direct Effects of Fructose on Adipocyte Precursor Cells

    Directory of Open Access Journals (Sweden)

    María Guillermina Zubiría

    2016-04-01

    Full Text Available We have previously addressed that fructose rich diet (FRD intake for three weeks increases the adipogenic potential of stromal vascular fraction cells from the retroperitoneal adipose tissue (RPAT. We have now evaluated the effect of prolonged FRD intake (eight weeks on metabolic parameters, number of adipocyte precursor cells (APCs and in vitro adipogenic potential from control (CTR and FRD adult male rats. Additionally, we have examined the direct fructose effects on the adipogenic capacity of normal APCs. FRD fed rats had increased plasma levels of insulin, triglyceride and leptin, and RPAT mass and adipocyte size. FACS studies showed higher APCs number and adipogenic potential in FRD RPAT pads; data is supported by high mRNA levels of competency markers: PPARγ2 and Zfp423. Complementary in vitro experiments indicate that fructose-exposed normal APCs displayed an overall increased adipogenic capacity. We conclude that the RPAT mass expansion observed in eight week-FRD fed rats depends on combined accelerated adipogenesis and adipocyte hypertrophy, partially due to a direct effect of fructose on APCs.

  11. Lymphokine-activated killer cell phenomenon. III. Evidence that IL-2 is sufficient for direct activation of peripheral blood lymphocytes into lymphokine-activated killer cells

    OpenAIRE

    1983-01-01

    Purified interleukin 2 (IL-2) was found to be sufficient for direct activation of peripheral blood lymphocytes into lymphokine-activated killer (LAK) cells. The LAK activation factor was directly and consistently associated with IL-2 activity using classic protein purification techniques, adsorption to IL-2-dependent cell lines, and inhibition with anti-Tac antibody. As yet, no other cytokines have been found that perform the same role.

  12. Direct hydrocarbon fuel cells

    Science.gov (United States)

    Barnett, Scott A.; Lai, Tammy; Liu, Jiang

    2010-05-04

    The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

  13. S14 protein in breast cancer cells: Direct evidence of regulation by SREBP-1c, superinduction with progestin, and effects on cell growth

    International Nuclear Information System (INIS)

    Most breast cancers exhibit brisk lipogenesis, and require it for growth. S14 is a lipogenesis-related nuclear protein that is overexpressed in most breast cancers. Sterol response element-binding protein-1c (SREBP-1c) is required for induction of lipogenesis-related genes, including S14 and fatty acid synthase (FAS), in hepatocytes, and correlation of SREBP-1c and FAS expression suggested that SREBP-1c drives lipogenesis in tumors as well. We directly tested the hypothesis that SREBP-1c drives S14 expression and mediates lipogenic effects of progestin in T47D breast cancer cells. Dominant-negative SREBP-1c inhibited induction of S14 and FAS mRNAs by progestin, while active SREBP-1c induced without hormone and superinduced in its presence. Changes in S14 mRNA were reflected in protein levels. A lag time and lack of progestin response elements indicated that S14 and FAS gene activation by progestin is indirect. Knockdown of S14 reduced, whereas overexpression stimulated, T47D cell growth, while nonlipogenic MCF10a mammary epithelial cells were not growth-inhibited. These data directly demonstrate that SREBP-1c drives S14 gene expression in breast cancer cells, and progestin magnifies that effect via an indirect mechanism. This supports the prediction, based on S14 gene amplification and overexpression in breast tumors, that S14 augments breast cancer cell growth and survival

  14. Somatostatin receptors are expressed by immature cerebellar granule cells: evidence for a direct inhibitory effect of somatostatin on neuroblast activity.

    OpenAIRE

    Gonzalez, B; Leroux, P.; Lamacz, M; Bodenant, C; Balazs, R.; Vaudry, H.

    1992-01-01

    Somatostatin and somatostatin receptors are transiently expressed in the immature rat cerebellar cortex but virtually undetectable in the cerebellum of adults. Although somatostatin binding sites have been visualized during the postnatal period in the external granule cell layer, the type of cell that expresses somatostatin receptors has never been identified; thus, the potential function of somatostatin in the developing cerebellum remains unknown. In the present study, we have taken advanta...

  15. Targeted alpha therapy in vivo: direct evidence for single cancer cell kill using {sup 149}Tb-rituximab

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, G.J.; Soloviev, D.; Buchegger, F. [Division of Nuclear Medicine, University Hospital of Geneva, 24 Rue Micheli du Crest, 1211, Geneva 14 (Switzerland); Miederer, M. [Department of Molecular Pharmacology and Chemistry, Memorial Sloan-Kettering Cancer Center, New York (United States); Vranjes-Duric, S. [Laboratory of Radioisotopes, Vinca Institute of Nuclear Sciences, Belgrade (Czechoslovakia); Comor, J.J. [Laboratory of Physics, Vinca Institute of Nuclear Sciences, Belgrade (Czechoslovakia); Kuenzi, G.; Hartley, O. [Department of Medical Biochemistry, University Medical Center, Geneva (Switzerland); Senekowitsch-Schmidtke, R. [Clinic of Nuclear Medicine, Technical University of Munich, Munich (Germany)

    2004-04-01

    This study demonstrates high-efficiency sterilisation of single cancer cells in a SCID mouse model of leukaemia using rituximab, a monoclonal antibody that targets CD20, labelled with terbium-149, an alpha-emitting radionuclide. Radio-immunotherapy with 5.5 MBq labelled antibody conjugate (1.11 GBq/mg) 2 days after an intravenous graft of 5.10{sup 6} Daudi cells resulted in tumour-free survival for >120 days in 89% of treated animals. In contrast, all control mice (no treatment or treated with 5 or 300 {mu}g unlabelled rituximab) developed lymphoma disease. At the end of the study period, 28.4%{+-}4% of the long-lived daughter activity remained in the body, of which 91.1% was located in bone tissue and 6.3% in the liver. A relatively high daughter radioactivity concentration was found in the spleen (12%{+-}2%/g), suggesting that the killed cancer cells are mainly eliminated through the spleen. This promising preliminary in vivo study suggests that targeted alpha therapy with {sup 149}Tb is worthy of consideration as a new-generation radio-immunotherapeutic approach. (orig.)

  16. Direct Methanol Fuel Cell, DMFC

    Directory of Open Access Journals (Sweden)

    Amornpitoksuk, P.

    2003-09-01

    Full Text Available Direct Methanol Fuel Cell, DMFC is a kind of fuel cell using methanol as a fuel for electric producing. Methanol is low cost chemical substance and it is less harmful than that of hydrogen fuel. From these reasons it can be commercial product. The electrocatalytic reaction of methanol fuel uses Pt-Ru metals as the most efficient catalyst. In addition, the property of membrane and system designation are also effect to the fuel cell efficient. Because of low power of methanol fuel cell therefore, direct methanol fuel cell is proper to use for the energy source of small electrical devices and vehicles etc.

  17. A cell's sense of direction.

    Science.gov (United States)

    Parent, C A; Devreotes, P N

    1999-04-30

    In eukaryotic cells directional sensing is mediated by heterotrimeric guanine nucleotide-binding protein (G protein)-linked signaling pathways. In Dictyostelium discoideum amoebae and mammalian leukocytes, the receptors and G-protein subunits are uniformly distributed around the cell perimeter. Chemoattractants induce the transient appearance of binding sites for several pleckstrin homology domain-containing proteins on the inner face of the membrane. In gradients of attractant these sites are persistently present on the side of the cell facing the higher concentration, even in the absence of a functional actin cytoskeleton or cell movement. Thus, the cell senses direction by spatially regulating the activity of the signal transduction pathway. PMID:10221901

  18. Evidence for Vitamin D Receptor Expression and Direct Effects of 1α,25(OH)2D3 in Human Skeletal Muscle Precursor Cells.

    Science.gov (United States)

    Olsson, Karl; Saini, Amarjit; Strömberg, Anna; Alam, Seher; Lilja, Mats; Rullman, Eric; Gustafsson, Thomas

    2016-01-01

    Presence of the vitamin D receptor and direct effects of vitamin D on the proliferation and differentiation of muscle precursor cells have been demonstrated in animal models. However, the effects and mechanisms of vitamin D actions in human skeletal muscle, and the presence of the vitamin D receptor in human adult skeletal muscle, remain to be established. Here, we investigated the role of vitamin D in human muscle cells at various stages of differentiation. We demonstrate that the components of the vitamin D-endocrine system are readily detected in human muscle precursor cells but are low to nondetectable in adult skeletal muscle and that human muscle cells lack the ability to convert the inactive vitamin D-metabolite 25-hydroxy-vitamin D3 to the active 1α,25-dihydroxy-vitamin D3 (1α,25(OH)2D3). In addition, we show that 1α,25(OH)2D3 inhibits myoblast proliferation and differentiation by altering the expression of cell cycle regulators and myogenic regulatory factors, with associated changes in forkhead box O3 and Notch signaling pathways. The present data add novel information regarding the direct effects of vitamin D in human skeletal muscle and provide functional and mechanistic insight to the regulation of myoblast cell fate decisions by 1α,25(OH)2D3. PMID:26469137

  19. Direct evidence for a stem cell common to hematopoiesis and its in vitro microenvironment: studies on syngeneic (inbred) Wistar Furth rats

    International Nuclear Information System (INIS)

    When injected into a group of lethally irradiated syngeneic (inbred) Wistar Furth (WF) rats, suspensions of stromal cells grown in monolayer culture from the marrow of WF rats produced hemopoietic colonies in the spleen and rescued 50% of the rats, while 90% of the non-injected (control) rats died within 30 days and had no hemopoietic colonies in the spleens. Fifty percent of the injected (test) rats which died between days 6 and 22 showed hemopoietic regeneration in the bone marrow, while little or no evidence of hemopoietic regeneration was seen in the control animals. Our results suggest that the marrow stroma grown in vitro contain cells with hemopoietic potential and are transplantable

  20. Morphine alters astrocyte growth in primary cultures of mouse glial cells: evidence for a direct effect of opiates on neural maturation

    Science.gov (United States)

    Stiene-Martin, Anne; Gurwell, Julie A.; Hauser, Kurt F.

    2016-01-01

    SUMMARY To determine whether exogenous opiate drugs with abuse liability directly modify neural growth, the present study investigated the effects of morphine on astrocyte proliferation and differentiation in primary cultures of murine glial cells. The results indicate that morphine decreases glial cell production in a dose-dependent, naloxone reversible manner. Most notably, gliogenesis virtually ceased in the presence of 10−6 M morphine during the first week in culture, whereas 10−8 M or 10−10 M morphine caused an intermediate suppression of growth compared to control or 10−6 M morphine treated cultures. Moreover, morphine-treatment inhibited [3H]thymidine incorporation by glial fibrillary acidic protein (GFAP) immunoreactive, flat (type 1) astrocytes, suggesting that the decrease in glial cell production was due in part to an inhibition of astrocyte proliferation. Morphine also caused significant increases in both cytoplasmic area and process elaboration in flat (type 1) astrocytes indicating greater morphologic differentiation. In the above experiments, morphine-dependent alterations in astrocyte growth were antagonized by naloxone, indicating that morphine action was mediated by specific opioid receptors. These observations suggest that opiate drugs can directly modify neural growth by influencing two critical developmental events in astrocytes, i.e., inhibiting proliferation and inducing morphologic differentiation. PMID:1914143

  1. Direct Methanol Fuel Cell, DMFC

    OpenAIRE

    Amornpitoksuk, P.

    2003-01-01

    Direct Methanol Fuel Cell, DMFC is a kind of fuel cell using methanol as a fuel for electric producing. Methanol is low cost chemical substance and it is less harmful than that of hydrogen fuel. From these reasons it can be commercial product. The electrocatalytic reaction of methanol fuel uses Pt-Ru metals as the most efficient catalyst. In addition, the property of membrane and system designation are also effect to the fuel cell efficient. Because of low power of methanol fuel cell therefor...

  2. In Vitro Evidence for Immune-Modulatory Properties of Non-Digestible Oligosaccharides: Direct Effect on Human Monocyte Derived Dendritic Cells.

    Directory of Open Access Journals (Sweden)

    Sarah Lehmann

    Full Text Available Infant formulas containing non-digestible oligosaccharides (NDO similar to the composition in breast milk or a combination of lactic acid bacteria (LAB and NDO have been shown to harbor preventive effects towards immune-regulatory disorders. The aim of this study was to investigate the immune-modulatory potential of non-digestible short chain galacto- and long chain fructo-oligosaccharides (scGOS/lcFOS mimicking the natural distribution of oligosaccharides in human breast milk in presence or absence of certain LAB strains in human monocyte derived dendritic cells (MoDC. Immature human MoDC prepared from peripheral blood of healthy non-atopic volunteers were screened in vitro after stimulation with specific scGOS/lcFOS in presence or absence of LAB. IL-10 and IL-12p70 release was analyzed after 24 hours in cell-free supernatants by enzyme-linked immunosorbent assay (ELISA. A luminex-based assay was conducted to assess further cytokine and chemokine release by MoDC. To investigate the resulting T cell response, stimulated MoDC were co-incubated with naïve T cells in allogeneic stimulation assays and intracellular Foxp3 expression, as well as immune-suppressive capacity was determined. Oligosaccharides did not induce relevant amounts of IL-12p70 production, but did promote IL-10 release by MoDC. Furthermore, scGOS/lcFOS mixtures exerted a significant enhancing effect on LAB induced IL-10 secretion by MoDC while no increase in IL-12p70 production was observed. Blocking toll like receptor (TLR4 abrogated the increase in IL-10 in both the direct stimulation and the LAB stimulation of MoDC, suggesting that scGOS/lcFOS act via TLR4. Finally, scGOS/lcFOS-treated MoDC were shown to upregulate the number of functional suppressive Foxp3 positive T cells following allogeneic stimulation. Our results indicate anti-inflammatory and direct, microbiota independent, immune-modulatory properties of scGOS/lcFOS mixtures on human MoDC suggesting a possible

  3. The direct methanol fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Halpert, G.; Narayanan, S.R.; Frank, H. [Jet Propulsion Lab., Pasadena, CA (United States)

    1995-08-01

    This presentation describes the approach and progress in the ARPA-sponsored effort to develop a Direct Methanol, Liquid-Feed Fuel Cell (DMLFFC) with a solid Polymer Electrolyte Membrane (PEM) for battery replacement in small portable applications. Using Membrane Electrode Assemblies (MEAs) developed by JPL and Giner, significant voltage was demonstrated at relatively high current densities. The DMLFFC utilizes a 3 percent aqueous solution of methanol that is oxidized directly in the anode (fuel) chamber and oxygen (air) in the cathode chamber to produce water and significant power. The only products are water and CO{sub 2}. The ARPA effort is aimed at replacing the battery in the BA 5590 military radio.

  4. Directional summation in non-direction selective retinal ganglion cells.

    Directory of Open Access Journals (Sweden)

    Syed Y Abbas

    Full Text Available Retinal ganglion cells receive inputs from multiple bipolar cells which must be integrated before a decision to fire is made. Theoretical studies have provided clues about how this integration is accomplished but have not directly determined the rules regulating summation of closely timed inputs along single or multiple dendrites. Here we have examined dendritic summation of multiple inputs along On ganglion cell dendrites in whole mount rat retina. We activated inputs at targeted locations by uncaging glutamate sequentially to generate apparent motion along On ganglion cell dendrites in whole mount retina. Summation was directional and dependent13 on input sequence. Input moving away from the soma (centrifugal resulted in supralinear summation, while activation sequences moving toward the soma (centripetal were linear. Enhanced summation for centrifugal activation was robust as it was also observed in cultured retinal ganglion cells. This directional summation was dependent on hyperpolarization activated cyclic nucleotide-gated (HCN channels as blockade with ZD7288 eliminated directionality. A computational model confirms that activation of HCN channels can override a preference for centripetal summation expected from cell anatomy. This type of direction selectivity could play a role in coding movement similar to the axial selectivity seen in locust ganglion cells which detect looming stimuli. More generally, these results suggest that non-directional retinal ganglion cells can discriminate between input sequences independent of the retina network.

  5. Directional summation in non-direction selective retinal ganglion cells.

    Science.gov (United States)

    Abbas, Syed Y; Hamade, Khaldoun C; Yang, Ellen J; Nawy, Scott; Smith, Robert G; Pettit, Diana L

    2013-01-01

    Retinal ganglion cells receive inputs from multiple bipolar cells which must be integrated before a decision to fire is made. Theoretical studies have provided clues about how this integration is accomplished but have not directly determined the rules regulating summation of closely timed inputs along single or multiple dendrites. Here we have examined dendritic summation of multiple inputs along On ganglion cell dendrites in whole mount rat retina. We activated inputs at targeted locations by uncaging glutamate sequentially to generate apparent motion along On ganglion cell dendrites in whole mount retina. Summation was directional and dependent13 on input sequence. Input moving away from the soma (centrifugal) resulted in supralinear summation, while activation sequences moving toward the soma (centripetal) were linear. Enhanced summation for centrifugal activation was robust as it was also observed in cultured retinal ganglion cells. This directional summation was dependent on hyperpolarization activated cyclic nucleotide-gated (HCN) channels as blockade with ZD7288 eliminated directionality. A computational model confirms that activation of HCN channels can override a preference for centripetal summation expected from cell anatomy. This type of direction selectivity could play a role in coding movement similar to the axial selectivity seen in locust ganglion cells which detect looming stimuli. More generally, these results suggest that non-directional retinal ganglion cells can discriminate between input sequences independent of the retina network. PMID:23516351

  6. Direct evidence for positron annihilation from shallow traps

    DEFF Research Database (Denmark)

    Linderoth, Søren; Hidalgo, C.

    1987-01-01

    For deformed Ag the temperature dependence of the positron lifetime parameters is followed between 12 and 300 K. Clear direct evidence for positron trapping and annihilation at shallow traps, with a positron binding energy of 9±2 meV and annihilation characteristics very similar to those in the...

  7. Direct evidence of milk consumption from ancient human dental calculus

    DEFF Research Database (Denmark)

    Warinner, C.; Hendy, J.; Speller, C.; Cappellini, E.; Fischer, R.; Trachsel, C.; Arneborg, Jette; Lynnerup, Niels; Craig, O.E.; Swallow, D.M.; Fotakis, A.; Christensen, R.J.; Olsen, J.V.; Liebert, A.; Montalva, N.; Fiddyment, S.; Carlton, S.; Mackie, M.; Canci, A.; Bouwman, A.; Rühli, F.; Gilbert, M.T.P.; Collins, M.J.

    2015-01-01

    Milk is a major food of global economic importance, and its consumption is regarded as a classic example of gene-culture evolution. Humans have exploited animal milk as a food resource for at least 8500 years, but the origins, spread, and scale of dairying remain poorly understood. Indirect lines...... of evidence, such as lipid isotopic ratios of pottery residues, faunal mortality profiles, and lactase persistence allele frequencies, provide a partial picture of this process; however, in order to understand how, where, and when humans consumed milk products, it is necessary to link evidence of...... consumption directly to individuals and their dairy livestock. Here we report the first direct evidence of milk consumption, the whey protein b-lactoglobulin (BLG), preserved in human dental calculus from the Bronze Age (ca. 3000 BCE) to the present day. Using protein tandem mass spectrometry, we demonstrate...

  8. Direct evidence of milk consumption from ancient human dental calculus

    DEFF Research Database (Denmark)

    Warinner, C; Hendy, J; Speller, C; Cappellini, Enrico; Fischer, R; Trachsel, C; Arneborg, J; Lynnerup, N; Craig, O E; Swallow, D M; Fotakis, A; Christensen, R J; Olsen, Jesper Velgaard; Liebert, A; Montalva, N; Fiddyment, S; Charlton, S; Mackie, M; Canci, A; Bouwman, A; Rühli, F; Gilbert, M T P; Collins, M J

    2014-01-01

    Milk is a major food of global economic importance, and its consumption is regarded as a classic example of gene-culture evolution. Humans have exploited animal milk as a food resource for at least 8500 years, but the origins, spread, and scale of dairying remain poorly understood. Indirect lines...... of evidence, such as lipid isotopic ratios of pottery residues, faunal mortality profiles, and lactase persistence allele frequencies, provide a partial picture of this process; however, in order to understand how, where, and when humans consumed milk products, it is necessary to link evidence of...... consumption directly to individuals and their dairy livestock. Here we report the first direct evidence of milk consumption, the whey protein β-lactoglobulin (BLG), preserved in human dental calculus from the Bronze Age (ca. 3000 BCE) to the present day. Using protein tandem mass spectrometry, we demonstrate...

  9. Children mix direct and indirect speech: evidence from pronoun comprehension.

    Science.gov (United States)

    Köder, Franziska; Maier, Emar

    2016-07-01

    This study investigates children's acquisition of the distinction between direct speech (Elephant said, "I get the football") and indirect speech (Elephant said that he gets the football), by measuring children's interpretation of first, second, and third person pronouns. Based on evidence from various linguistic sources, we hypothesize that the direct-indirect distinction is acquired relatively late. We also predict more mistakes for third person pronouns compared to first and second person pronouns. We tested 136 Dutch-speaking children between four and twelve in a referent selection task and found that children interpret pronouns in direct speech predominantly as in indirect speech, supporting our hypothesis about a late acquisition of the direct-indirect distinction. In addition, we found differences between I, you, and he that deviate from a simple first and second vs. third person split. We discuss our results in the light of cross-linguistic findings of direct-indirect mixing. PMID:26121990

  10. Parallel-up structure evidences the molecular directionality during biosynthesis of bacterial cellulose

    OpenAIRE

    Koyama, Makiko; Helbert, William; Imai, Tomoya; Sugiyama, Junji; Henrissat, Bernard

    1997-01-01

    The “parallel-up” packing in cellulose Iα and Iβ unit cells was experimentally demonstrated by a combination of direct-staining the reducing ends of cellulose chains and microdiffraction-tilting electron crystallographic analysis. Microdiffraction investigation of nascent bacterial cellulose microfibrils showed that the reducing end of the growing cellulose chains points away from the bacterium, and this provides direct evidence that polymerization by the cellulose synthase takes place at the...

  11. Direct Evidence of Washing out of Nuclear Shell Effects

    CERN Document Server

    Chaudhuri, A; Banerjee, K; Bhattacharya, S; Sadhukhan, Jhilam; Bhattacharya, C; Kundu, S; Meena, J K; Mukherjee, G; Pandey, R; Rana, T K; Roy, P; Roy, T; Srivastava, V; Bhattacharya, P

    2015-01-01

    Constraining excitation energy at which nuclear shell effect washes out has important implications on the production of super heavy elements and many other fields of nuclear physics research. We report the fission fragment mass distribution in alpha induced reaction on an actinide target for wide excitation range in close energy interval and show direct evidence that nuclear shell effect washes out at excitation energy ~40 MeV. Calculation shows that second peak of the ?fission barrier also vanishes around similar excitation energy.

  12. Direct reprogramming of somatic cells: an update

    Directory of Open Access Journals (Sweden)

    Phuc Van Pham

    2015-03-01

    Full Text Available Direct epigenetic reprogramming is a technique that converts a differentiated adult cell into another differentiated cell and mdash;such fibroblasts to cardiomyocytes and mdash;without passage through an undifferentiated pluripotent stage. This novel technology is opening doors in biological research and regenerative medicine. Some preliminary studies about direct reprogramming started in the 1980s when differentiated adult cells could be converted into other differentiated cells by overexpressing transcription-factor genes. These studies also showed that differentiated cells have plasticity. Direct reprogramming can be a powerful tool in biological research and regenerative medicine, especially the new frontier of personalized medicine. This review aims to summarize all direct reprogramming studies of somatic cells by master control genes as well as potential applications of these techniques in research and treatment of selected human diseases. [Biomed Res Ther 2015; 2(3.000: 231-240

  13. Nestin(+) cells direct inflammatory cell migration in atherosclerosis.

    Science.gov (United States)

    Del Toro, Raquel; Chèvre, Raphael; Rodríguez, Cristina; Ordóñez, Antonio; Martínez-González, José; Andrés, Vicente; Méndez-Ferrer, Simón

    2016-01-01

    Atherosclerosis is a leading death cause. Endothelial and smooth muscle cells participate in atherogenesis, but it is unclear whether other mesenchymal cells contribute to this process. Bone marrow (BM) nestin(+) cells cooperate with endothelial cells in directing monocyte egress to bloodstream in response to infections. However, it remains unknown whether nestin(+) cells regulate inflammatory cells in chronic inflammatory diseases, such as atherosclerosis. Here, we show that nestin(+) cells direct inflammatory cell migration during chronic inflammation. In Apolipoprotein E (ApoE) knockout mice fed with high-fat diet, BM nestin(+) cells regulate the egress of inflammatory monocytes and neutrophils. In the aorta, nestin(+) stromal cells increase ∼30 times and contribute to the atheroma plaque. Mcp1 deletion in nestin(+) cells-but not in endothelial cells only- increases circulating inflammatory cells, but decreases their aortic infiltration, delaying atheroma plaque formation and aortic valve calcification. Therefore, nestin expression marks cells that regulate inflammatory cell migration during atherosclerosis. PMID:27586429

  14. Direct evidence of epithelial-mesenchymal interdependence in situ.

    OpenAIRE

    Adatia, A K

    1980-01-01

    In the basal odontogenic zone of the mandibular incisor of the rat the cytological evidence of the toxicity of 40 mg cyclophosphamide per kg, 24 hours following a single intraperitoneal injection, was confined to the proliferating mesenchyme. Localised loss of precursors of odontoblasts cessation of basal odontogenesis and acellularity of the related part of the pulp ensured. The cells of the internal enamel epithelium bordering this region did not differentiate into ameloblasts and appeared ...

  15. THE EXPLANATORY VARIABLES OF OUTWARD FOREIGN DIRECT INVESTMENT: PANEL EVIDENCE

    Directory of Open Access Journals (Sweden)

    Nicholas Apergis

    2012-01-01

    Full Text Available Along with the traditional macroeconomic determinants of FDI, additional explanatory variables, such as the exchange rates, should be encountered in undertaking physical investment decisions, as these variables affect several comparative costs and the cost of lending. The goal of this study is to examine for the first time panel data evidence of Greek outward FDI flows directed to 16 EU and non-EU countries over the period 1997-2008, focusing on the relative importance of emerging variables on the determination of the direction of FDI. The results clearly show that-under different specifications-increases in the level of exchange, affect FDI flows directed from Greece to the host economies. Moreover, significant determinants for the streaming of the Greek FDI are the minimum wage rate and the labour productivity in the host economies as well as the price of the Greek physical capital.

  16. Hepatitis C virus cell-cell transmission and resistance to direct-acting antiviral agents

    DEFF Research Database (Denmark)

    Xiao, Fei; Fofana, Isabel; Heydmann, Laura;

    2014-01-01

    -targeting entry inhibitors (HTEIs) was highly effective in inhibiting viral dissemination of resistant genotype 2 viruses. Combining HTEIs with DAAs prevented antiviral resistance and led to rapid elimination of the virus in cell culture model. In conclusion, our work provides evidence that cell-cell transmission......Hepatitis C virus (HCV) is transmitted between hepatocytes via classical cell entry but also uses direct cell-cell transfer to infect neighboring hepatocytes. Viral cell-cell transmission has been shown to play an important role in viral persistence allowing evasion from neutralizing antibodies. In...... contrast, the role of HCV cell-cell transmission for antiviral resistance is unknown. Aiming to address this question we investigated the phenotype of HCV strains exhibiting resistance to direct-acting antivirals (DAAs) in state-of-the-art model systems for cell-cell transmission and spread. Using HCV...

  17. Direct evidence of milk consumption from ancient human dental calculus.

    Science.gov (United States)

    Warinner, C; Hendy, J; Speller, C; Cappellini, E; Fischer, R; Trachsel, C; Arneborg, J; Lynnerup, N; Craig, O E; Swallow, D M; Fotakis, A; Christensen, R J; Olsen, J V; Liebert, A; Montalva, N; Fiddyment, S; Charlton, S; Mackie, M; Canci, A; Bouwman, A; Rühli, F; Gilbert, M T P; Collins, M J

    2014-01-01

    Milk is a major food of global economic importance, and its consumption is regarded as a classic example of gene-culture evolution. Humans have exploited animal milk as a food resource for at least 8500 years, but the origins, spread, and scale of dairying remain poorly understood. Indirect lines of evidence, such as lipid isotopic ratios of pottery residues, faunal mortality profiles, and lactase persistence allele frequencies, provide a partial picture of this process; however, in order to understand how, where, and when humans consumed milk products, it is necessary to link evidence of consumption directly to individuals and their dairy livestock. Here we report the first direct evidence of milk consumption, the whey protein β-lactoglobulin (BLG), preserved in human dental calculus from the Bronze Age (ca. 3000 BCE) to the present day. Using protein tandem mass spectrometry, we demonstrate that BLG is a species-specific biomarker of dairy consumption, and we identify individuals consuming cattle, sheep, and goat milk products in the archaeological record. We then apply this method to human dental calculus from Greenland's medieval Norse colonies, and report a decline of this biomarker leading up to the abandonment of the Norse Greenland colonies in the 15(th) century CE. PMID:25429530

  18. Methods of conditioning direct methanol fuel cells

    Science.gov (United States)

    Rice, Cynthia; Ren, Xiaoming; Gottesfeld, Shimshon

    2005-11-08

    Methods for conditioning the membrane electrode assembly of a direct methanol fuel cell ("DMFC") are disclosed. In a first method, an electrical current of polarity opposite to that used in a functioning direct methanol fuel cell is passed through the anode surface of the membrane electrode assembly. In a second method, methanol is supplied to an anode surface of the membrane electrode assembly, allowed to cross over the polymer electrolyte membrane of the membrane electrode assembly to a cathode surface of the membrane electrode assembly, and an electrical current of polarity opposite to that in a functioning direct methanol fuel cell is drawn through the membrane electrode assembly, wherein methanol is oxidized at the cathode surface of the membrane electrode assembly while the catalyst on the anode surface is reduced. Surface oxides on the direct methanol fuel cell anode catalyst of the membrane electrode assembly are thereby reduced.

  19. Direct evidence of milk consumption from ancient human dental calculus

    DEFF Research Database (Denmark)

    Warinner, C.; Hendy, J.; Speller, C.;

    2014-01-01

    Milk is a major food of global economic importance, and its consumption is regarded as a classic example of gene-culture evolution. Humans have exploited animal milk as a food resource for at least 8500 years, but the origins, spread, and scale of dairying remain poorly understood. Indirect lines...... consumption directly to individuals and their dairy livestock. Here we report the first direct evidence of milk consumption, the whey protein β-lactoglobulin (BLG), preserved in human dental calculus from the Bronze Age (ca. 3000 BCE) to the present day. Using protein tandem mass spectrometry, we demonstrate...... that BLG is a species-specific biomarker of dairy consumption, and we identify individuals consuming cattle, sheep, and goat milk products in the archaeological record. We then apply this method to human dental calculus from Greenland's medieval Norse colonies, and report a decline of this biomarker...

  20. Capnography during cardiopulmonary resuscitation: Current evidence and future directions

    Directory of Open Access Journals (Sweden)

    Bhavani Shankar Kodali

    2014-01-01

    Full Text Available Capnography continues to be an important tool in measuring expired carbon dioxide (CO 2 . Most recent Advanced Cardiac Life Support (ACLS guidelines now recommend using capnography to ascertain the effectiveness of chest compressions and duration of cardiopulmonary resuscitation (CPR. Based on an extensive review of available published literature, we selected all available peer-reviewed research investigations and case reports. Available evidence suggests that there is significant correlation between partial pressure of end-tidal CO 2 (PETCO 2 and cardiac output that can indicate the return of spontaneous circulation (ROSC. Additional evidence favoring the use of capnography during CPR includes definitive proof of correct placement of the endotracheal tube and possible prediction of patient survival following cardiac arrest, although the latter will require further investigations. There is emerging evidence that PETCO 2 values can guide the initiation of extracorporeal life support (ECLS in refractory cardiac arrest (RCA. There is also increasing recognition of the value of capnography in intensive care settings in intubated patients. Future directions include determining the outcomes based on capnography waveforms PETCO 2 values and determining a reasonable duration of CPR. In the future, given increasing use of capnography during CPR large databases can be analyzed to predict outcomes.

  1. Directed hepatic differentiation from embryonic stem cells

    OpenAIRE

    Chen, Xuesong; Zeng, Fanyi

    2011-01-01

    The liver is the largest internal organ in mammals, and is important for the maintenance of normal physiological functions of other tissues and organs. Hepatitis, cirrhosis, liver cancer and other chronic liver diseases are serious threats to human health, and these problems are compounded by a scarcity of liver donors for transplantation therapies. Directed differentiation of embryonic stem cells to liver cells is a promising strategy for obtaining hepatocytes that can be used for cell trans...

  2. Hepatitis C virus cell-cell transmission and resistance to direct-acting antiviral agents.

    Directory of Open Access Journals (Sweden)

    Fei Xiao

    2014-05-01

    Full Text Available Hepatitis C virus (HCV is transmitted between hepatocytes via classical cell entry but also uses direct cell-cell transfer to infect neighboring hepatocytes. Viral cell-cell transmission has been shown to play an important role in viral persistence allowing evasion from neutralizing antibodies. In contrast, the role of HCV cell-cell transmission for antiviral resistance is unknown. Aiming to address this question we investigated the phenotype of HCV strains exhibiting resistance to direct-acting antivirals (DAAs in state-of-the-art model systems for cell-cell transmission and spread. Using HCV genotype 2 as a model virus, we show that cell-cell transmission is the main route of viral spread of DAA-resistant HCV. Cell-cell transmission of DAA-resistant viruses results in viral persistence and thus hampers viral eradication. We also show that blocking cell-cell transmission using host-targeting entry inhibitors (HTEIs was highly effective in inhibiting viral dissemination of resistant genotype 2 viruses. Combining HTEIs with DAAs prevented antiviral resistance and led to rapid elimination of the virus in cell culture model. In conclusion, our work provides evidence that cell-cell transmission plays an important role in dissemination and maintenance of resistant variants in cell culture models. Blocking virus cell-cell transmission prevents emergence of drug resistance in persistent viral infection including resistance to HCV DAAs.

  3. Direct evidence for W exchange in charmed meson decay

    International Nuclear Information System (INIS)

    Using the ARGUS detector at DORIS II, we have observed a signal of 36.7+-8.0 events in the decay channel D0 -> Ksub(s)0PHI. In the same data sample, we have observed the well established decay D0 -> Ksub(s)0π+π-, and find the ratio, Br(D0 -> Ksub(s)0PHI)/Br(D0 -> Ksub(s)0π+π-), to be 0.186+-0.052. The substantial value of (0.99+-0.32+-0.17)% then derived for the branching ratio for D0 -> anti K0PHI gives direct evidence that W exchange contributes to D0 decay. (orig.)

  4. Direct Cytoskeleton Forces Cause Membrane Softening in Red Blood Cells

    Science.gov (United States)

    Rodríguez-García, Ruddi; López-Montero, Iván; Mell, Michael; Egea, Gustavo; Gov, Nir S.; Monroy, Francisco

    2015-01-01

    Erythrocytes are flexible cells specialized in the systemic transport of oxygen in vertebrates. This physiological function is connected to their outstanding ability to deform in passing through narrow capillaries. In recent years, there has been an influx of experimental evidence of enhanced cell-shape fluctuations related to metabolically driven activity of the erythroid membrane skeleton. However, no direct observation of the active cytoskeleton forces has yet been reported to our knowledge. Here, we show experimental evidence of the presence of temporally correlated forces superposed over the thermal fluctuations of the erythrocyte membrane. These forces are ATP-dependent and drive enhanced flickering motions in human erythrocytes. Theoretical analyses provide support for a direct force exerted on the membrane by the cytoskeleton nodes as pulses of well-defined average duration. In addition, such metabolically regulated active forces cause global membrane softening, a mechanical attribute related to the functional erythroid deformability. PMID:26083919

  5. Direct formate fuel cells: A review

    Science.gov (United States)

    An, L.; Chen, R.

    2016-07-01

    Direct formate fuel cells (DFFC), which convert the chemical energy stored in formate directly into electricity, are recently attracting more attention, primarily because of the use of the carbon-neutral fuel and the low-cost electrocatalytic and membrane materials. As an emerging energy technology, the DFFC has made a rapid progress in recent years (currently, the state-of-the-art power density is 591 mW cm-2 at 60 °C). This article provides a review of past research on the development of this type of fuel cell, including the working principle, mechanisms and materials of the electrocatalytic oxidation of formate, singe-cell designs and performance, as well as innovative system designs. In addition, future perspectives with regard to the development of this fuel cell system are also highlighted.

  6. Ruthenium dissolution in direct methanol fuel cells

    OpenAIRE

    Schökel, Alexander

    2015-01-01

    The lifetime of a direct methanol fuel cell (DMFC) is mostly determined by the degradation of its active component, the membrane electrode assembly (MEA). Besides degradation of the proton conducting membrane, the aging of the electrodes and especially the catalysts therein is the major limiting factor. One of the catalyst degradation mechanisms is ruthenium dissolution. This work is the first extensive study on the dissolution, migration and deposition of ruthenium in a DMFC single cell d...

  7. Alignment of cell division axes in directed epithelial cell migration

    International Nuclear Information System (INIS)

    Cell division is an essential dynamic event in tissue remodeling during wound healing, cancer and embryogenesis. In collective migration, tensile stresses affect cell shape and polarity, hence, the orientation of the cell division axis is expected to depend on cellular flow patterns. Here, we study the degree of orientation of cell division axes in migrating and resting epithelial cell sheets. We use microstructured channels to create a defined scenario of directed cell invasion and compare this situation to resting but proliferating cell monolayers. In experiments, we find a strong alignment of the axis due to directed flow while resting sheets show very weak global order, but local flow gradients still correlate strongly with the cell division axis. We compare experimental results with a previously published mesoscopic particle based simulation model. Most of the observed effects are reproduced by the simulations. (paper)

  8. Uterine stem cells: what is the evidence?

    Science.gov (United States)

    Gargett, C E

    2007-01-01

    The mucosal lining (endometrium) of the human uterus undergoes cyclical processes of regeneration, differentiation and shedding as part of the menstrual cycle. Endometrial regeneration also follows parturition, almost complete resection and in post-menopausal women taking estrogen replacement therapy. In non-menstruating species, there are cycles of endometrial growth and apoptosis rather than physical shedding. The concept that endometrial stem/progenitor cells are responsible for the remarkable regenerative capacity of endometrium was proposed many years ago. However, attempts to isolate, characterize and locate endometrial stem cells have only been undertaken in the last few years as experimental approaches to identify adult stem/progenitor cells in other tissues have been developed. Adult stem cells are defined by their functional properties rather than by marker expression. Evidence for the existence of adult stem/progenitor cells in human and mouse endometrium is now emerging because functional stem cell assays are being applied to uterine cells and tissues. These fundamental studies on endometrial stem/progenitor cells will provide new insights into the pathophysiology of various gynaecological disorders associated with abnormal endometrial proliferation, including endometrial cancer, endometrial hyperplasia, endometriosis and adenomyosis. PMID:16960017

  9. FIRST DIRECT EVIDENCE THAT BARIUM DWARFS HAVE WHITE DWARF COMPANIONS

    International Nuclear Information System (INIS)

    Barium II (Ba) stars are chemically peculiar F-, G-, and K-type objects that show enhanced abundances of s-process elements. Since s-process nucleosynthesis is unlikely to take place in stars prior to the advanced asymptotic giant branch (AGB) stage, the prevailing hypothesis is that each present Ba star was contaminated by an AGB companion which is now a white dwarf (WD). Unless the initial mass ratio of such a binary was fairly close to unity, the receiving star is thus at least as likely to be a dwarf as a giant. So although most known Ba stars appear to be giants, the hypothesis requires that Ba dwarfs be comparably plentiful and moreover that they should all have WD companions. However, despite dedicated searches with the IUE satellite, no WD companions have been directly detected to date among the classical Ba dwarfs, even though some 90% of those stars are spectroscopic binaries, so the contamination hypothesis is therefore presently in some jeopardy. In this paper, we analyze recent deep, near-UV and far-UV Galaxy Evolution Explorer (GALEX) exposures of four of the brightest of the class (HD 2454, 15360, 26367, and 221531), together with archived GALEX data for two newly recognized Ba dwarfs: HD 34654 and HD 114520 (which also prove to be spectroscopic binaries). The GALEX observations of the Ba dwarfs as a group show a significant far-UV excess compared to a control sample of normal F-type dwarfs. We suggest that this ensemble far-UV excess constitutes the first direct evidence that Ba dwarfs have WD companions.

  10. Chrysler Pentastar direct hydrogen fuel cell program

    Energy Technology Data Exchange (ETDEWEB)

    Kimble, M.; Deloney, D.

    1995-08-01

    The Chrysler Pentastar Electronics, Inc. Direct Hydrogen Fueled PEM Fuel Cell Hybrid Vehicle Program (DPHV) was initiated 1 July, 1994 with the following mission, {open_quotes}Design, fabricate, and test a Direct Hydrogen Fueled Proton Exchange Membrane (PEM) Fuel Cell System including onboard hydrogen storage, an efficient lightweight fuel cell, a gas management system, peak power augmentation and a complete system controls that can be economically mass produced and comply with all safety environmental and consumer requirements for vehicle applications for the 21st century.{close_quotes} The Conceptual Design for the entire system based upon the selection of an applicable vehicle and performance requirements that are consistent with the PNGV goals will be discussed. A Hydrogen Storage system that has been selected, packaged, and partially tested in accordance with perceived Hydrogen Safety and Infrastructure requirements will be discussed in addition to our Fuel Cell approach along with design of the {open_quotes}real{close_quotes} module. The Gas Management System and the Load Leveling System have been designed and the software programs have been developed and will be discussed along with a complete fuel cell test station that has the capability to test up to a 60 kW fuel cell system.

  11. Direct fuel cell product design improvement

    Energy Technology Data Exchange (ETDEWEB)

    Maru, H.C.; Farooque, M. [Energy Research Corp., Danbury, CT (United States)

    1996-12-31

    Significant milestones have been attained towards the technology development field testing and commercialization of direct fuel cell power plant since the 1994 Fuel Cell Seminar. Under a 5-year cooperative agreement with the Department of Energy signed in December 1994, Energy Research Corporation (ERC) has been developing the design for a MW-scale direct fuel cell power plant with input from previous technology efforts and the Santa Clara Demonstration Project. The effort encompasses product definition in consultation with the Fuel Cell Commercialization Group, potential customers, as well as extensive system design and packaging. Manufacturing process improvements, test facility construction, cell component scale up, performance and endurance improvements, stack engineering, and critical balance-of-plant development are also addressed. Major emphasis of this product design improvement project is on increased efficiency, compactness and cost reduction to establish a competitive place in the market. A 2.85 MW power plant with an efficiency of 58% and a footprint of 420 m{sup 2} has been designed. Component and subsystem testing is being conducted at various levels. Planning and preparation for verification of a full size prototype unit are in progress. This paper presents the results obtained since the last fuel cell seminar.

  12. Direct behavioral evidence for retronasal olfaction in rats.

    Directory of Open Access Journals (Sweden)

    Shree Hari Gautam

    Full Text Available The neuroscience of flavor perception is becoming increasingly important to understand abnormal feeding behaviors and associated chronic diseases such as obesity. Yet, flavor research has mainly depended on human subjects due to the lack of an animal model. A crucial step towards establishing an animal model of flavor research is to determine whether the animal uses the retronasal mode of olfaction, an essential element of flavor perception. We designed a go- no go behavioral task to test the rat's ability to detect and discriminate retronasal odorants. In this paradigm, tasteless aqueous solutions of odorants were licked by water-restricted head-fixed rats from a lick spout. Orthonasal contamination was avoided by employing a combination of a vacuum around the lick-spout and blowing clean air toward the nose. Flow models support the effectiveness of both approaches. The licked odorants were successfully discriminated by rats. Moreover, the tasteless odorant amyl acetate was reliably discriminated against pure distilled water in a concentration-dependent manner. The results from this retronasal odor discrimination task suggest that rats are capable of smelling retronasally. This direct behavioral evidence establishes the rat as a useful animal model for flavor research.

  13. Direct cell lysis for single-cell gene expression profiling

    Directory of Open Access Journals (Sweden)

    DavidSvec

    2013-11-01

    Full Text Available The interest to analyze single and few cell samples is rapidly increasing. Numerous extraction protocols to purify nucleic acids are available, but most of them compromise severely on yield to remove contaminants and are therefore not suitable for the analysis of samples containing small numbers of transcripts only. Here, we evaluate 17 direct cell lysis protocols for transcript yield and compatibility with downstream reverse transcription quantitative real-time PCR. Four endogenously expressed genes are assayed together with RNA and DNA spikes in the samples. We found bovine serum albumin (BSA to be the best lysis agent, resulting in efficient cell lysis, high RNA stability and enhanced reverse transcription efficiency. Furthermore, we found direct cell lysis with BSA superior to standard column based extraction methods, when analyzing from 1 up to 512 mammalian cells. In conclusion, direct cell lysis protocols based on BSA can be applied with most cell collection methods and are compatible with most analytical workflows to analyze single cells as well as samples composed of small numbers of cells.

  14. Silicon Based Direct Methanol Fuel Cells

    OpenAIRE

    Larsen, Jackie Vincent; Thomsen, Erik Vilain

    2013-01-01

    The purpose of this project has been to investigate and fabricate small scale Micro Direct Methanol Fuel Cells (μDMFC). They are investigated as a possible alternative for Zinc-air batteries in small size consumer devices such as hearing aids. In such devices the conventional rechargeable batteries such as lithium-ion batteries have insufficiently low energy density. Methanol is a promising fuel for such devices due to the high energy density and ease of refueling compared to charging batteri...

  15. Electrocatalysts for direct alcohol fuel cells

    OpenAIRE

    Celorrio, V.

    2013-01-01

    The properties of CNC as well as their surface chemistry can be tuned by an adequate choice of synthesis conditions, favouring the formation of surface oxygen groups. Platinum-based catalysts have been supported on CNCs through different synthesis methods and their catalytic activity has been proven. These results prove that CNCs are promising candidates as alternative to replace Vulcan in order to improve the performance of the direct alcohol fuel cells. In addition, it can be affirmed that ...

  16. Silicon Based Direct Methanol Fuel Cells

    DEFF Research Database (Denmark)

    Larsen, Jackie Vincent

    fabrication techniques where utilized to build μDMFCs with the purpose of engineering the structures, both on the micro and nano scales in order to realize a high level of control over the membrane and catalyst components. The work presents four different monolithic fuel cell designs. The primary design is......The purpose of this project has been to investigate and fabricate small scale Micro Direct Methanol Fuel Cells (μDMFC). They are investigated as a possible alternative for Zinc-air batteries in small size consumer devices such as hearing aids. In such devices the conventional rechargeable batteries...... into the current collector electrodes. This design is based on catalytic in situ growth of carbon nanotubes and atomic layer deposition of active catalyst particles. The additional two fuel cell designs utilize a porous silicon structure as the mechanical support, using respectively a spray coated...

  17. Direct Evidence Linking Soil Organic Matter Development to Microbial Communities

    Science.gov (United States)

    Kallenbach, C.; Grandy, S.

    2013-12-01

    Despite increasing recognition of microbial contributions to soil organic matter (SOM) formation there is little experimental evidence linking microbial processes to SOM development and the mechanisms responsible remain unclear. Specifically, if stable SOM is largely comprised of microbial products, we need to better understand the soil conditions that influence microbial biomass production and ultimately its stability. Microbial physiology, such as microbial growth efficiency (MGE) and rate (MGR) have direct influences on microbial biomass production and are highly sensitive to resource quality. Therefore, the importance of resource quality on SOM is not necessarily a function of resistance to decay but the degree to which it optimizes microbial biomass production. While resource quality may have an indirect effect on SOM abundance via its influence on microbial physiology, SOM stabilization of labile microbial products may rely heavily on a soil's capacity to form organo-mineral interactions. To examine the relative importance of soil microbial community function, resource quality and mineralogy on direct microbial contributions to SOM formation and stability, an ongoing 15-mo incubation experiment was set up using artificial, initially C- and microbial-free soils. Soil microcosms were constructed by mixing sand with either kaolinite or montmorillonite clays followed with a natural soil microbial inoculum. For both soil mineral treatments, weekly additions of glucose, cellobiose, or syringol are carried out, with an additional treatment of plant leachate to serve as a reference. This simplified system allows us to determine if, in the absence of plant-derived C, microbial products using simple substrates can result in chemically complex SOM similar to natural soils. Over the course of the incubation, MGE, MGR, microbial activity, and SOM accumulation rates are monitored. Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) is used to track the microbial

  18. Foreign Direct Investment and Economic Growth: Evidence from Sri Lanka

    OpenAIRE

    Thirunavukkarasu Velnampy; Sivapalan Achchuthan; Rajendran Kajananthan

    2013-01-01

    Various international organizations and foreign advisors suggested that developing countries should focusprimarily on foreign direct investment (FDI) as a source of external finance. In this context, the main purpose ofthe study is to find out the impact of foreign direct investment on economic growth in the Sri LankanPerspective. Data on the foreign direct investment and economic growth from the year 1990 to 2011 werecollected for the study purpose. Further, the results revealed that, there ...

  19. Direct FuelCell/Turbine Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Hossein Ghezel-Ayagh

    2008-09-30

    This report summarizes the progress made in development of Direct FuelCell/Turbine (DFC/T{reg_sign}) power plants for generation of clean power at very high efficiencies. The DFC/T system employs an indirectly heated Turbine Generator to supplement fuel cell generated power. The concept extends the high efficiency of the fuel cell by utilizing the fuel cell's byproduct heat in a Brayton cycle. Features of the DFC/T system include: electrical efficiencies of up to 75% on natural gas, minimal emissions, reduced carbon dioxide release to the environment, simplicity in design, direct reforming internal to the fuel cell, and potential cost competitiveness with existing combined cycle power plants. Proof-of-concept tests using a sub-MW-class DFC/T power plant at FuelCell Energy's (FCE) Danbury facility were conducted to validate the feasibility of the concept and to measure its potential for electric power production. A 400 kW-class power plant test facility was designed and retrofitted to conduct the tests. The initial series of tests involved integration of a full-size (250 kW) Direct FuelCell stack with a 30 kW Capstone microturbine. The operational aspects of the hybrid system in relation to the integration of the microturbine with the fuel cell, process flow and thermal balances, and control strategies for power cycling of the system, were investigated. A subsequent series of tests included operation of the sub-MW Direct FuelCell/Turbine power plant with a Capstone C60 microturbine. The C60 microturbine extended the range of operation of the hybrid power plant to higher current densities (higher power) than achieved in initial tests using the 30kW microturbine. The proof-of-concept test results confirmed the stability and controllability of operating a fullsize (250 kW) fuel cell stack in combination with a microturbine. Thermal management of the system was confirmed and power plant operation, using the microturbine as the only source of fresh air supply

  20. Direct FuelCell/Turbine Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Hossein Ghezel-Ayagh

    2008-09-30

    This report summarizes the progress made in development of Direct FuelCell/Turbine (DFC/T{reg_sign}) power plants for generation of clean power at very high efficiencies. The DFC/T system employs an indirectly heated Turbine Generator to supplement fuel cell generated power. The concept extends the high efficiency of the fuel cell by utilizing the fuel cell's byproduct heat in a Brayton cycle. Features of the DFC/T system include: electrical efficiencies of up to 75% on natural gas, minimal emissions, reduced carbon dioxide release to the environment, simplicity in design, direct reforming internal to the fuel cell, and potential cost competitiveness with existing combined cycle power plants. Proof-of-concept tests using a sub-MW-class DFC/T power plant at FuelCell Energy's (FCE) Danbury facility were conducted to validate the feasibility of the concept and to measure its potential for electric power production. A 400 kW-class power plant test facility was designed and retrofitted to conduct the tests. The initial series of tests involved integration of a full-size (250 kW) Direct FuelCell stack with a 30 kW Capstone microturbine. The operational aspects of the hybrid system in relation to the integration of the microturbine with the fuel cell, process flow and thermal balances, and control strategies for power cycling of the system, were investigated. A subsequent series of tests included operation of the sub-MW Direct FuelCell/Turbine power plant with a Capstone C60 microturbine. The C60 microturbine extended the range of operation of the hybrid power plant to higher current densities (higher power) than achieved in initial tests using the 30kW microturbine. The proof-of-concept test results confirmed the stability and controllability of operating a fullsize (250 kW) fuel cell stack in combination with a microturbine. Thermal management of the system was confirmed and power plant operation, using the microturbine as the only source of fresh air supply

  1. Selectivity of Direct Methanol Fuel Cell Membranes

    Directory of Open Access Journals (Sweden)

    Antonino S. Aricò

    2015-11-01

    Full Text Available Sulfonic acid-functionalized polymer electrolyte membranes alternative to Nafion® were developed. These were hydrocarbon systems, such as blend sulfonated polyetheretherketone (s-PEEK, new generation perfluorosulfonic acid (PFSA systems, and composite zirconium phosphate–PFSA polymers. The membranes varied in terms of composition, equivalent weight, thickness, and filler and were investigated with regard to their methanol permeation characteristics and proton conductivity for application in direct methanol fuel cells. The behavior of the membrane electrode assemblies (MEA was investigated in fuel cell with the aim to individuate a correlation between membrane characteristics and their performance in a direct methanol fuel cell (DMFC. The power density of the DMFC at 60 °C increased according to a square root-like function of the membrane selectivity. This was defined as the reciprocal of the product between area specific resistance and crossover. The power density achieved at 60 °C for the most promising s-PEEK-based membrane-electrode assembly (MEA was higher than the benchmark Nafion® 115-based MEA (77 mW·cm−2 vs. 64 mW·cm−2. This result was due to a lower methanol crossover (47 mA·cm−2 equivalent current density for s-PEEK vs. 120 mA·cm−2 for Nafion® 115 at 60 °C as recorded at OCV with 2 M methanol and a suitable area specific resistance (0.15 Ohm cm2 for s-PEEK vs. 0.22 Ohm cm2 for Nafion® 115.

  2. Experimental evidence for directed percolation in spatiotemporal intermittency

    OpenAIRE

    Rupp, Peter; Richter, Reinhard; Rehberg, Ingo

    2002-01-01

    A new experimental system showing a transition to spatiotemporal intermittency is presented. It consists of a ring of hundred oscillating ferrofluidic spikes. The measured critical exponents of the system agree with those obtained from a theoretical model of directed percolation.

  3. Direct evidence for T violation in the neutral kaon system

    International Nuclear Information System (INIS)

    The first direct observation of T violation in the neutral kaon system, is presented showing a positive signal with a significance of more than two standard deviations. The results does not rely on the validity of the CPT theorem. (author)

  4. Directing the public to evidence-based online content

    OpenAIRE

    Cooper, Crystale Purvis; Gelb, Cynthia A; Vaughn, Alexandra N; Smuland, Jenny; Hughes, Alexandra G; Hawkins, Nikki A.

    2014-01-01

    To direct online users searching for gynecologic cancer information to accurate content, the Centers for Disease Control and Prevention’s (CDC) ‘Inside Knowledge: Get the Facts About Gynecologic Cancer’ campaign sponsored search engine advertisements in English and Spanish. From June 2012 to August 2013, advertisements appeared when US Google users entered search terms related to gynecologic cancer. Users who clicked on the advertisements were directed to relevant content on the CDC website. ...

  5. Direct evidence of milk consumption from ancient human dental calculus

    OpenAIRE

    Warinner, Christina; Hendy, Jessica Ruth; Speller, Camilla Filomena; Cappellini, Enrico; Fischer, Roman; Trachsel, Christian; Arneborg, J; Lynnerup, N; Craig, Oliver Edward; Swallow, DM; Fotakis, Anna; Christensen, RJ; Olsen, JV; Liebert, A.; Montalva, N

    2014-01-01

    Milk is a major food of global economic importance, and its consumption is regarded as a classic example of gene-culture evolution. Humans have exploited animal milk as a food resource for at least 8500 years, but the origins, spread, and scale of dairying remain poorly understood. Indirect lines of evidence, such as lipid isotopic ratios of pottery residues, faunal mortality profiles, and lactase persistence allele frequencies, provide a partial picture of this process; however, in order to ...

  6. Capnography during cardiopulmonary resuscitation: Current evidence and future directions

    OpenAIRE

    Bhavani Shankar Kodali; Urman, Richard D.

    2014-01-01

    Capnography continues to be an important tool in measuring expired carbon dioxide (CO 2 ). Most recent Advanced Cardiac Life Support (ACLS) guidelines now recommend using capnography to ascertain the effectiveness of chest compressions and duration of cardiopulmonary resuscitation (CPR). Based on an extensive review of available published literature, we selected all available peer-reviewed research investigations and case reports. Available evidence suggests that there is significant correlat...

  7. Cost Sharing in Medicaid: Assumptions, Evidence, and Future Directions.

    Science.gov (United States)

    Powell, Victoria; Saloner, Brendan; Sabik, Lindsay M

    2016-08-01

    Several states have received waivers to expand Medicaid to poor adults under the Affordable Care Act using more cost sharing than the program traditionally allows. We synthesize literature on the effects of cost sharing, focusing on studies of low-income U.S. populations from 1995 to 2014. Literature suggests that cost sharing has a deterrent effect on initiation of treatments, and can reduce utilization of ongoing treatments. Furthermore, cost sharing may be difficult for low-income populations to understand, patients often lack sufficient information to choose medical treatment, and cost sharing may be difficult to balance within the budgets of poor adults. Gaps in the literature include evidence of long-term effects of cost sharing on health and financial well-being, evidence related to effectiveness of cost sharing combined with patient education, and evidence related to targeted programs that use financial incentives for wellness. Literature underscores the need for evaluation of the effects of cost sharing on health status and spending, particularly among the poorest adults. PMID:26602175

  8. Electrocatalysts for direct alcohol fuel cells

    Directory of Open Access Journals (Sweden)

    V. Celorrio

    2013-01-01

    Full Text Available The properties of CNC as well as their surface chemistry can be tuned by an adequate choice of synthesis conditions, favouring the formation of surface oxygen groups. Platinum-based catalysts have been supported on CNCs through different synthesis methods and their catalytic activity has been proven. These results prove that CNCs are promising candidates as alternative to replace Vulcan in order to improve the performance of the direct alcohol fuel cells. In addition, it can be affirmed that the reactivity of Au-Pd core-shell nanostructures toward CO and HCOOH electro-oxidation is not only determined by the composition and structure of Pd overlayer but also by interaction with the support.

  9. Self Directed Support and People with Learning Disabilities: A Review of the Published Research Evidence

    Science.gov (United States)

    Harkes, Mary Anne; Brown, Michael; Horsburgh, Dorothy

    2014-01-01

    A systematic literature review was undertaken to determine the evidence base underpinning the strategy of Self Directed Support and whether evidence demonstrates that this policy is accessible to everyone with a learning disability. It also sought to identify whether there were any barriers to Self Directed Support for people with severe or…

  10. Foreign Direct Investment Location Choice Factors: Some Evidence for Brazil

    Directory of Open Access Journals (Sweden)

    Romana KOREZ-VIDE

    2014-12-01

    Full Text Available Due to the liberalization and transformation of emerging markets economies, the attractiveness of these countries for foreign direct investors has been rising in the last decades. This paper explores foreign direct investment (FDI location choice factors of German and Austrian companies in Brazilian regions. We perform a quantitative analysis, based on the Multinomial Nested Logit Model and supplement its findings by the qualitative analysis, based on the semi-structured experts’ interview. The analyses show that investor-nation specific agglomeration, industry specialization, workforce qualification and physical infrastructure were important FDI location choice factors for German and Austrian companies in Brazil. Suggestions for future research of the FDI location choice factors are discussed.

  11. Recognizing intentions in infant-directed speech: evidence for universals.

    Science.gov (United States)

    Bryant, Gregory A; Barrett, H Clark

    2007-08-01

    In all languages studied to date, distinct prosodic contours characterize different intention categories of infant-directed (ID) speech. This vocal behavior likely exists universally as a species-typical trait, but little research has examined whether listeners can accurately recognize intentions in ID speech using only vocal cues, without access to semantic information. We recorded native-English-speaking mothers producing four intention categories of utterances (prohibition, approval, comfort, and attention) as both ID and adult-directed (AD) speech, and we then presented the utterances to Shuar adults (South American hunter-horticulturalists). Shuar subjects were able to reliably distinguish ID from AD speech and were able to reliably recognize the intention categories in both types of speech, although performance was significantly better with ID speech. This is the first demonstration that adult listeners in an indigenous, nonindustrialized, and nonliterate culture can accurately infer intentions from both ID speech and AD speech in a language they do not speak. PMID:17680948

  12. Determinants of direct foreign investment: Evidence from Jordan

    Directory of Open Access Journals (Sweden)

    Walid Zakaria Siam

    2010-04-01

    Full Text Available In order to show the effect of direct foreign investment flows on the economy of Jordan, this studycomes to examine the economic and financial risks on FDI on the macro level over the period (1997-2007. This study applies a version of the model developed by Chan and Gemayel (2004 by usingMultiple Linear Regression Model. The analysis revealed that there exists significant and positiverelationship between foreign direct investment flows into the economy of Jordan and economic andfinancial variables. The study claims for further FDI promotion through incentives to attract newinvestments. These factors are: providing targeted fiscal incentives, such as tax concessions, cash grants,and specific subsidies; improving domestic infrastructure; promoting local skills development to meetinvestor needs and expectations; establishing broad-reaching FDI promotion agencies and improvingthe regulatory environment and decreasing red tape.

  13. Determinants of Foreign Direct Investment : Evidence from Malaysia

    OpenAIRE

    Tan, Kah Chun

    2011-01-01

    The aim of this paper is to examine and explore the determinants influencing Foreign Direct Investment (FDI) inflows into Malaysia. The period under study is 40 years, covering from year 1970 to 2009. Drawing upon existing literature on FDI, some findings on both developed and developing countries in earlier empirical works are investigated for Malaysia. From a host country‟s policy point of view, the study suggests that increase in GDP per capita (market size), infrastructure development, tr...

  14. Recognizing intentions in infant-directed speech: Evidence for universals

    OpenAIRE

    Bryant, GA; Barrett, HC

    2007-01-01

    In all languages studied to date, distinct prosodic contours characterize different intention categories of infant-directed (ID) speech. This vocal behavior likely exists universally as a species-typical trait, but little research has examined whether listeners can accurately recognize intentions in ID speech using only vocal cues, without access to semantic information. We recorded native-English-speaking mothers producing four intention categories of utterances (prohibition, approval, comfo...

  15. Direct Evidence of Egestion and Salivation of Xylella fastidiosa Suggests Sharpshooters Can Be "Flying Syringes".

    Science.gov (United States)

    Backus, Elaine A; Shugart, Holly J; Rogers, Elizabeth E; Morgan, J Kent; Shatters, Robert

    2015-05-01

    Xylella fastidiosa is unique among insect-transmitted plant pathogens because it is propagative but noncirculative, adhering to and multiplying on the cuticular lining of the anterior foregut. Any inoculation mechanism for X. fastidiosa must explain how bacterial cells exit the vector's stylets via the food canal and directly enter the plant. A combined egestion-salivation mechanism has been proposed to explain these unique features. Egestion is the putative outward flow of fluid from the foregut via hypothesized bidirectional pumping of the cibarium. The present study traced green fluorescent protein-expressing X. fastidiosa or fluorescent nanoparticles acquired from artificial diets by glassy-winged sharpshooters, Homalodisca vitripennis, as they were egested into simultaneously secreted saliva. X. fastidiosa or nanoparticles were shown to mix with gelling saliva to form fluorescent deposits and salivary sheaths on artificial diets, providing the first direct, conclusive evidence of egestion by any hemipteran insect. Therefore, the present results strongly support an egestion-salivation mechanism of X. fastidiosa inoculation. Results also support that a column of fluid is transiently held in the foregut without being swallowed. Evidence also supports (but does not definitively prove) that bacteria were suspended in the column of fluid during the vector's transit from diet to diet, and were egested with the held fluid. Thus, we hypothesize that sharpshooters could be true "flying syringes," especially when inoculation occurs very soon after uptake of bacteria, suggesting the new paradigm of a nonpersistent X. fastidiosa transmission mechanism. PMID:26020829

  16. Direct evidence of void passivation in Cu(InGa)(SSe)2 absorber layers

    International Nuclear Information System (INIS)

    We have investigated the charge collection condition around voids in copper indium gallium sulfur selenide (CIGSSe) solar cells fabricated by sputter and a sequential process of selenization/sulfurization. In this study, we found direct evidence of void passivation by using the junction electron beam induced current method, transmission electron microscopy, and energy dispersive X-ray spectroscopy. The high sulfur concentration at the void surface plays an important role in the performance enhancement of the device. The recombination around voids is effectively suppressed by field-assisted void passivation. Hence, the generated carriers are easily collected by the electrodes. Therefore, when the S/(S + Se) ratio at the void surface is over 8% at room temperature, the device performance degradation caused by the recombination at the voids is negligible at the CIGSSe layer

  17. Laser-based direct-write techniques for cell printing

    Science.gov (United States)

    Schiele, Nathan R; Corr, David T; Huang, Yong; Raof, Nurazhani Abdul; Xie, Yubing; Chrisey, Douglas B

    2016-01-01

    Fabrication of cellular constructs with spatial control of cell location (±5 μm) is essential to the advancement of a wide range of applications including tissue engineering, stem cell and cancer research. Precise cell placement, especially of multiple cell types in co- or multi-cultures and in three dimensions, can enable research possibilities otherwise impossible, such as the cell-by-cell assembly of complex cellular constructs. Laser-based direct writing, a printing technique first utilized in electronics applications, has been adapted to transfer living cells and other biological materials (e.g., enzymes, proteins and bioceramics). Many different cell types have been printed using laser-based direct writing, and this technique offers significant improvements when compared to conventional cell patterning techniques. The predominance of work to date has not been in application of the technique, but rather focused on demonstrating the ability of direct writing to pattern living cells, in a spatially precise manner, while maintaining cellular viability. This paper reviews laser-based additive direct-write techniques for cell printing, and the various cell types successfully laser direct-written that have applications in tissue engineering, stem cell and cancer research are highlighted. A particular focus is paid to process dynamics modeling and process-induced cell injury during laser-based cell direct writing. PMID:20814088

  18. Direct methanol feed fuel cell and system

    Science.gov (United States)

    Surampudi, Subbarao (Inventor); Frank, Harvey A. (Inventor); Narayanan, Sekharipuram R. (Inventor); Chun, William (Inventor); Jeffries-Nakamura, Barbara (Inventor); Kindler, Andrew (Inventor); Halpert, Gerald (Inventor)

    2009-01-01

    Improvements to non acid methanol fuel cells include new formulations for materials. The platinum and ruthenium are more exactly mixed together. Different materials are substituted for these materials. The backing material for the fuel cell electrode is specially treated to improve its characteristics. A special sputtered electrode is formed which is extremely porous. The fuel cell system also comprises a fuel supplying part including a meter which meters an amount of fuel which is used by the fuel cell, and controls the supply of fuel based on said metering.

  19. Direction-Setting School Leadership Practices: A Meta-Analytical Review of Evidence about Their Influence

    Science.gov (United States)

    Sun, Jingping; Leithwood, Kenneth

    2015-01-01

    This study reviews evidence about the overall influence of direction-setting leadership practices (DSLPs), 1 of 4 major categories of practices included in a widely known conception of effective leadership (e.g., Leithwood & Louis, 2011) and a focus of many other such conceptions, as well. This study also inquires about how direction-setting…

  20. Direct Evidence that RNA Inhibits APOBEC3G ssDNA Cytidine Deaminase Activity

    Science.gov (United States)

    McDougall, William M.; Smith, Harold C.

    2011-01-01

    APOBEC3G (A3G) is a deoxycytidine deaminase active on ssDNA substrates. In HIV infected cells A3G interacted with reverse transcription complexes where its activity as a deoxycytidine deaminase led to mutation of the viral genome. A3G not only bound ssDNA, but it also had an intrinsic ability to bind RNA. In many cell types that can support HIV replication, A3G ssDNA deaminase activity was suppressed and the enzyme resided in high molecular mass, ribonucleoprotein complexes associated with cytoplasmic P-bodies and stress granules. Using a defined in vitro system, we show that RNA alone was sufficient to suppress A3G deaminase activity and did so in an RNA concentration-dependent manner. RNAs of diverse sequences and as short as 25 nucleotides were effective inhibitors. Native PAGE analyses showed that RNA formed ribonucleoprotein complexes with A3G and in so doing prevented ssDNA substrates from binding to A3G. The data provided direct evidence that A3G binding to cellular RNAs constituted a substantial impediment to the enzyme’s ability to interact with ssDNA. PMID:21856286

  1. Leader Cells Define Directionality of Trunk, but Not Cranial, Neural Crest Cell Migration.

    Science.gov (United States)

    Richardson, Jo; Gauert, Anton; Briones Montecinos, Luis; Fanlo, Lucía; Alhashem, Zainalabdeen Mohmammed; Assar, Rodrigo; Marti, Elisa; Kabla, Alexandre; Härtel, Steffen; Linker, Claudia

    2016-05-31

    Collective cell migration is fundamental for life and a hallmark of cancer. Neural crest (NC) cells migrate collectively, but the mechanisms governing this process remain controversial. Previous analyses in Xenopus indicate that cranial NC (CNC) cells are a homogeneous population relying on cell-cell interactions for directional migration, while chick embryo analyses suggest a heterogeneous population with leader cells instructing directionality. Our data in chick and zebrafish embryos show that CNC cells do not require leader cells for migration and all cells present similar migratory capacities. In contrast, laser ablation of trunk NC (TNC) cells shows that leader cells direct movement and cell-cell contacts are required for migration. Moreover, leader and follower identities are acquired before the initiation of migration and remain fixed thereafter. Thus, two distinct mechanisms establish the directionality of CNC cells and TNC cells. This implies the existence of multiple molecular mechanisms for collective cell migration. PMID:27210753

  2. Single cell activity reveals direct electron transfer in methanotrophic consortia

    Science.gov (United States)

    McGlynn, Shawn E.; Chadwick, Grayson L.; Kempes, Christopher P.; Orphan, Victoria J.

    2015-10-01

    Multicellular assemblages of microorganisms are ubiquitous in nature, and the proximity afforded by aggregation is thought to permit intercellular metabolic coupling that can accommodate otherwise unfavourable reactions. Consortia of methane-oxidizing archaea and sulphate-reducing bacteria are a well-known environmental example of microbial co-aggregation; however, the coupling mechanisms between these paired organisms is not well understood, despite the attention given them because of the global significance of anaerobic methane oxidation. Here we examined the influence of interspecies spatial positioning as it relates to biosynthetic activity within structurally diverse uncultured methane-oxidizing consortia by measuring stable isotope incorporation for individual archaeal and bacterial cells to constrain their potential metabolic interactions. In contrast to conventional models of syntrophy based on the passage of molecular intermediates, cellular activities were found to be independent of both species intermixing and distance between syntrophic partners within consortia. A generalized model of electric conductivity between co-associated archaea and bacteria best fit the empirical data. Combined with the detection of large multi-haem cytochromes in the genomes of methanotrophic archaea and the demonstration of redox-dependent staining of the matrix between cells in consortia, these results provide evidence for syntrophic coupling through direct electron transfer.

  3. Wdpcp, a PCP protein required for ciliogenesis, regulates directional cell migration and cell polarity by direct modulation of the actin cytoskeleton.

    Directory of Open Access Journals (Sweden)

    Cheng Cui

    2013-11-01

    Full Text Available Planar cell polarity (PCP regulates cell alignment required for collective cell movement during embryonic development. This requires PCP/PCP effector proteins, some of which also play essential roles in ciliogenesis, highlighting the long-standing question of the role of the cilium in PCP. Wdpcp, a PCP effector, was recently shown to regulate both ciliogenesis and collective cell movement, but the underlying mechanism is unknown. Here we show Wdpcp can regulate PCP by direct modulation of the actin cytoskeleton. These studies were made possible by recovery of a Wdpcp mutant mouse model. Wdpcp-deficient mice exhibit phenotypes reminiscent of Bardet-Biedl/Meckel-Gruber ciliopathy syndromes, including cardiac outflow tract and cochlea defects associated with PCP perturbation. We observed Wdpcp is localized to the transition zone, and in Wdpcp-deficient cells, Sept2, Nphp1, and Mks1 were lost from the transition zone, indicating Wdpcp is required for recruitment of proteins essential for ciliogenesis. Wdpcp is also found in the cytoplasm, where it is localized in the actin cytoskeleton and in focal adhesions. Wdpcp interacts with Sept2 and is colocalized with Sept2 in actin filaments, but in Wdpcp-deficient cells, Sept2 was lost from the actin cytoskeleton, suggesting Wdpcp is required for Sept2 recruitment to actin filaments. Significantly, organization of the actin filaments and focal contacts were markedly changed in Wdpcp-deficient cells. This was associated with decreased membrane ruffling, failure to establish cell polarity, and loss of directional cell migration. These results suggest the PCP defects in Wdpcp mutants are not caused by loss of cilia, but by direct disruption of the actin cytoskeleton. Consistent with this, Wdpcp mutant cochlea has normal kinocilia and yet exhibits PCP defects. Together, these findings provide the first evidence, to our knowledge, that a PCP component required for ciliogenesis can directly modulate the actin

  4. Nano-gold Catalyst for Direct Alcohol Fuel Cells

    Institute of Scientific and Technical Information of China (English)

    Z.Ogumi; K.Miyazaki; Y.Iriyama; T.Abe

    2007-01-01

    1 Results Direct alcohol fuel cells have been regarded as attractive power sources for portable electric devices. One of the major roadblocks to the implementation of direct alcohol fuel cells is the exploration of the anode catalyst that can electrochemically oxidize alcohols at lower potentials. Carbon-monoxide (CO) produced through alcohol oxidation deteriorates catalytic activity of Pt, and therefore, the high tolerance for CO poisoning is an important issue to attain high voltage from direct alcoho...

  5. Alpha scintillation cell for direct measurement of indoor radon

    International Nuclear Information System (INIS)

    A large volume (1500 cm3) alpha scintillation cell to measure indoor radon is described. Air is sampled directly into the cell and gross alpha activity is measured after three hours. The cells are suitable for concentrations higher than 10-20 Bq/m3. They were successfully used for randon measurements in kindergartens in Nova Gorica. 7 refs., 2 figs., 1 tab

  6. Influence of engineered surface on cell directionality and motility

    International Nuclear Information System (INIS)

    Control of cell migration is important in numerous key biological processes, and is implicated in pathological conditions such as cancer metastasis and inflammatory diseases. Many previous studies indicated that cell migration could be guided by micropatterns fabricated on cell culture surfaces. In this study, we designed a polydimethylsiloxane cell culture substrate with gratings punctuated by corners and ends, and studied its effects on the behavior of MC3T3-E1 osteoblast cells. MC3T3-E1 cells elongated and aligned with the gratings, and the migration paths of the cells appeared to be guided by the grating pattern. Interestingly, more than 88% of the cells cultured on these patterns were observed to reverse their migration directions at least once during the 16 h examination period. Most of the reversal events occurred at the corners and the ends of the pattern, suggesting these localized topographical features induce an abrupt loss in directional persistence. Moreover, the cell speed was observed to increase temporarily right after each directional reversal. Focal adhesion complexes were more well-established in cells on the angular gratings than on flat surfaces, but the formation of filipodia appeared to be imbalanced at the corners and the ends, possibly leading to the loss of directional persistence. This study describes the first engineered cell culture surface that consistently induces changes in the directional persistence of adherent cells. This will provide an experimental model for the study of this phenomenon and a valuable platform to control the cell motility and directionality, which can be used for cell screening and selection. (paper)

  7. Synergy between chemotherapy and alpha particles: effects in cells directly hit and in bystander cells

    International Nuclear Information System (INIS)

    Full text: Radioimmunotherapy with alpha-emitting nuclides offers the potential for selective targeting of micrometastatic sites. The short range of alpha particles and limited penetration of the labeled antibody into the tumor make it difficult to deliver a lethal dose to all tumor cells. In an effort to improve the extent and uniformity of tumor cell kill, experiments are underway to evaluate the ability of chemotherapy agents to produce synergistic effects in cells directly hit by alpha particles and in bystander cells. An alpha particle cell irradiation system comprised of planar americium-241 alpha particle sources together with custom-made cell culture dishes with replaceable mylar bottoms has been constructed and characterized. By changing the alpha particle source, the dose rate to cells on the mylar membrane can be varied from 0.0013 Gy/min to 13 Gy/min. The residual range of the alpha particles after exiting the mylar membrane is approximately 30 ∝/m. Preliminary results with alpha particle exposure in the presence or absence of low concentrations of either taxol or oxaliplatin show evidence of synergistic effects. A series of plastic grids have been designed and constructed that can be interposed between the alpha particle source and the cells to partially block the alpha particles. The ratio of open area to shielded area is kept constant at 50% but the diameter and total number of circular openings in the grid is varied, thus changing the proportion of bystander cells present close to the edge between the open and shielded zones. This approach creates a two-dimensional model system for micrometastatic tumors of various sizes where the shielded areas represent the deeper portions of a tumor beyond the range of surface-bound alpha particles. Experiments are underway to determine whether there are synergistic effects between the chemotherapy agents and the bystander cells

  8. Femto Cells: Current Status and Future Directions

    Directory of Open Access Journals (Sweden)

    Khaled Elleithy

    2011-03-01

    Full Text Available This is a survey paper on the recently developed and rapidly evolving field of femtocells. Quite often, it isnoticed that cell-phone signals are strongly attenuated, when indoors, leading to call dropping or poor callquality. Femtocells are mini base stations that are deployed in users’ homes so that the user can directlyconnect to the cellular network through the femtocell instead of the outdoor macrocell, thereby increasingcall quality. In the later stages of the paper, we also discuss the integration of the femtocell into the 3Garchitecture, as well as the various interference issues that the femtocell faces.

  9. Astrocytes Directly Influence Tumor Cell Invasion and Metastasis In Vivo

    OpenAIRE

    Wang, Ling; Cossette, Stephanie M.; Rarick, Kevin R.; Gershan, Jill; Michael B Dwinell; Harder, David R.; Ramchandran, Ramani

    2013-01-01

    Brain metastasis is a defining component of tumor pathophysiology, and the underlying mechanisms responsible for this phenomenon are not well understood. Current dogma is that tumor cells stimulate and activate astrocytes, and this mutual relationship is critical for tumor cell sustenance in the brain. Here, we provide evidence that primary rat neonatal and adult astrocytes secrete factors that proactively induced human lung and breast tumor cell invasion and metastasis capabilities. Among wh...

  10. Direct methanol fuel cell and system

    Science.gov (United States)

    Wilson, Mahlon S.

    2004-10-26

    A fuel cell having an anode and a cathode and a polymer electrolyte membrane located between anode and cathode gas diffusion backings uses a methanol vapor fuel supply. A permeable polymer electrolyte membrane having a permeability effective to sustain a carbon dioxide flux equivalent to at least 10 mA/cm.sup.2 provides for removal of carbon dioxide produced at the anode by reaction of methanol with water. Another aspect of the present invention includes a superabsorpent polymer material placed in proximity to the anode gas diffusion backing to hold liquid methanol or liquid methanol solution without wetting the anode gas diffusion backing so that methanol vapor from the liquid methanol or liquid methanol-water solution is supplied to the membrane.

  11. Naive Pluripotent Stem Cells Derived Directly from Isolated Cells of the Human Inner Cell Mass.

    Science.gov (United States)

    Guo, Ge; von Meyenn, Ferdinand; Santos, Fatima; Chen, Yaoyao; Reik, Wolf; Bertone, Paul; Smith, Austin; Nichols, Jennifer

    2016-04-12

    Conventional generation of stem cells from human blastocysts produces a developmentally advanced, or primed, stage of pluripotency. In vitro resetting to a more naive phenotype has been reported. However, whether the reset culture conditions of selective kinase inhibition can enable capture of naive epiblast cells directly from the embryo has not been determined. Here, we show that in these specific conditions individual inner cell mass cells grow into colonies that may then be expanded over multiple passages while retaining a diploid karyotype and naive properties. The cells express hallmark naive pluripotency factors and additionally display features of mitochondrial respiration, global gene expression, and genome-wide hypomethylation distinct from primed cells. They transition through primed pluripotency into somatic lineage differentiation. Collectively these attributes suggest classification as human naive embryonic stem cells. Human counterparts of canonical mouse embryonic stem cells would argue for conservation in the phased progression of pluripotency in mammals. PMID:26947977

  12. Naive Pluripotent Stem Cells Derived Directly from Isolated Cells of the Human Inner Cell Mass

    Directory of Open Access Journals (Sweden)

    Ge Guo

    2016-04-01

    Full Text Available Conventional generation of stem cells from human blastocysts produces a developmentally advanced, or primed, stage of pluripotency. In vitro resetting to a more naive phenotype has been reported. However, whether the reset culture conditions of selective kinase inhibition can enable capture of naive epiblast cells directly from the embryo has not been determined. Here, we show that in these specific conditions individual inner cell mass cells grow into colonies that may then be expanded over multiple passages while retaining a diploid karyotype and naive properties. The cells express hallmark naive pluripotency factors and additionally display features of mitochondrial respiration, global gene expression, and genome-wide hypomethylation distinct from primed cells. They transition through primed pluripotency into somatic lineage differentiation. Collectively these attributes suggest classification as human naive embryonic stem cells. Human counterparts of canonical mouse embryonic stem cells would argue for conservation in the phased progression of pluripotency in mammals.

  13. On computational and behavioral evidence regarding Hebbian transcortical cell assemblies.

    OpenAIRE

    Spivey, M. J.; Andrews, M. W.; Richardson, D. C.

    1999-01-01

    Pulvermuller restricts himself to an unnecessarily narrow range of evidence to support his claims. Evidence from neural modeling and behavioral experiments provides further support for an account of words encoded as transcortical cell assemblies. A cognitive neuroscience of language must include a range of methodologies (e.g., neural, computational, and behavioral) and will need to focus on the on-line processes of real-time language processing in more natural contexts.

  14. New directions in evidence-based policy research: a critical analysis of the literature.

    Science.gov (United States)

    Oliver, Kathryn; Lorenc, Theo; Innvær, Simon

    2014-01-01

    Despite 40 years of research into evidence-based policy (EBP) and a continued drive from both policymakers and researchers to increase research uptake in policy, barriers to the use of evidence are persistently identified in the literature. However, it is not clear what explains this persistence - whether they represent real factors, or if they are artefacts of approaches used to study EBP. Based on an updated review, this paper analyses this literature to explain persistent barriers and facilitators. We critically describe the literature in terms of its theoretical underpinnings, definitions of 'evidence', methods, and underlying assumptions of research in the field, and aim to illuminate the EBP discourse by comparison with approaches from other fields. Much of the research in this area is theoretically naive, focusing primarily on the uptake of research evidence as opposed to evidence defined more broadly, and privileging academics' research priorities over those of policymakers. Little empirical data analysing the processes or impact of evidence use in policy is available to inform researchers or decision-makers. EBP research often assumes that policymakers do not use evidence and that more evidence - meaning research evidence - use would benefit policymakers and populations. We argue that these assumptions are unsupported, biasing much of EBP research. The agenda of 'getting evidence into policy' has side-lined the empirical description and analysis of how research and policy actually interact in vivo. Rather than asking how research evidence can be made more influential, academics should aim to understand what influences and constitutes policy, and produce more critically and theoretically informed studies of decision-making. We question the main assumptions made by EBP researchers, explore the implications of doing so, and propose new directions for EBP research, and health policy. PMID:25023520

  15. Ratchetaxis: Long-Range Directed Cell Migration by Local Cues.

    Science.gov (United States)

    Caballero, David; Comelles, Jordi; Piel, Matthieu; Voituriez, Raphaël; Riveline, Daniel

    2015-12-01

    Directed cell migration is usually thought to depend on the presence of long-range gradients of either chemoattractants or physical properties such as stiffness or adhesion. However, in vivo, chemical or mechanical gradients have not systematically been observed. Here we review recent in vitro experiments, which show that other types of spatial guidance cues can bias cell motility. Introducing local geometrical or mechanical anisotropy in the cell environment, such as adhesive/topographical microratchets or tilted micropillars, show that local and periodic external cues can direct cell motion. Together with modeling, these experiments suggest that cell motility can be viewed as a stochastic phenomenon, which can be biased by various types of local cues, leading to directional migration. PMID:26615123

  16. On direct and indirect methanol fuel cells for transportation applications

    Energy Technology Data Exchange (ETDEWEB)

    Gottesfield, S.

    1996-04-01

    Research on direct oxidation methanol fuel cells (DMFCs) and polymer electrolyte fuel cells (PEFCs) is discussed. Systems considered for transportation applications are addressed. The use of platinum/ruthenium anode electrocatalysts and platinum cathode electrocatalysts in polymer electrolyte DMFCs has resulted in significant performance enhancements.

  17. On direct hydrogen fuel cell vehicles : modelling and demonstration

    OpenAIRE

    Haraldsson, Kristina

    2005-01-01

    In this thesis, direct hydrogen Proton Exchange Membrane (PEM) fuel cell systems in vehicles are investigated through modelling, field tests and public acceptance surveys. A computer model of a 50 kW PEM fuel cell system was developed. The fuel cell system efficiency is approximately 50% between 10 and 45% of the rated power. The fuel cell auxiliary system, e.g. compressor and pumps, was shown to clearly affect the overall fuel cell system electrical efficiency. Two hydrogen on-board storage ...

  18. An innovative method of modeling direct methanol fuel cells

    OpenAIRE

    Anna Trendewicz; Jaroslaw Milewski

    2012-01-01

    In this paper a computer model of a direct methanol fuel cell (DMFC) developed with the use of HYSYS software was presented. Chemical reactions of methanol oxidation and oxygen reduction were executed in HYSYS software which eliminated the need of creating a complex electrochemical model of these reactions. Obtained resutls were used for determining maximum cell voltage and limiting current density of the investigated fuel cell. An equivalent electrical circuit ...

  19. Direct and indirect evidence for earthquakes; an example from the Lake Tahoe Basin, California-Nevada

    Science.gov (United States)

    Maloney, J. M.; Noble, P. J.; Driscoll, N. W.; Kent, G.; Schmauder, G. C.

    2012-12-01

    High-resolution seismic CHIRP data can image direct evidence of earthquakes (i.e., offset strata) beneath lakes and the ocean. Nevertheless, direct evidence often is not imaged due to conditions such as gas in the sediments, or steep basement topography. In these cases, indirect evidence for earthquakes (i.e., debris flows) may provide insight into the paleoseismic record. The four sub-basins of the tectonically active Lake Tahoe Basin provide an ideal opportunity to image direct evidence for earthquake deformation and compare it to indirect earthquake proxies. We present results from high-resolution seismic CHIRP surveys in Emerald Bay, Fallen Leaf Lake, and Cascade Lake to constrain the recurrence interval on the West Tahoe Dollar Point Fault (WTDPF), which was previously identified as potentially the most hazardous fault in the Lake Tahoe Basin. Recently collected CHIRP profiles beneath Fallen Leaf Lake image slide deposits that appear synchronous with slides in other sub-basins. The temporal correlation of slides between multiple basins suggests triggering by events on the WTDPF. If correct, we postulate a recurrence interval for the WTDPF of ~3-4 k.y., indicating that the WTDPF is near its seismic recurrence cycle. In addition, CHIRP data beneath Cascade Lake image strands of the WTDPF that offset the lakefloor as much as ~7 m. The Cascade Lake data combined with onshore LiDAR allowed us to map the geometry of the WTDPF continuously across the southern Lake Tahoe Basin and yielded an improved geohazard assessment.

  20. Macroscopic Modeling of Transport Phenomena in Direct Methanol Fuel Cells

    DEFF Research Database (Denmark)

    Olesen, Anders Christian

    An increasing need for energy efficiency and high energy density has sparked a growing interest in direct methanol fuel cells for portable power applications. This type of fuel cell directly generates electricity from a fuel mixture consisting of methanol and water. Although this technology...... surpasses batteries in important areas, fundamental research is still required to improve durability and performance. Particularly the transport of methanol and water within the cell structure is difficult to study in-situ. A demand therefore exist for the fundamental development of mathematical models for...... studying their transport. In this PhD dissertation the macroscopic transport phenomena governing direct methanol fuel cell operation are analyzed, discussed and modeled using the two-fluid approach in the computational fluid dynamics framework of CFX 14. The overall objective of this work is to extend the...

  1. Extracellular matrix components direct porcine muscle stem cell behavior

    International Nuclear Information System (INIS)

    In muscle tissue, extracellular matrix proteins, together with the vasculature system, muscle-residence cells and muscle fibers, create the niche for muscle stem cells. The niche is important in controlling proliferation and directing differentiation of muscle stem cells to sustain muscle tissue. Mimicking the extracellular muscle environment improves tools exploring the behavior of primary muscle cells. Optimizing cell culture conditions to maintain muscle commitment is important in stem cell-based studies concerning toxicology screening, ex vivo skeletal muscle tissue engineering and in the enhancement of clinical efficiency. We used the muscle extracellular matrix proteins collagen type I, fibronectin, laminin, and also gelatin and Matrigel as surface coatings of tissue culture plastic to resemble the muscle extracellular matrix. Several important factors that determine myogenic commitment of the primary muscle cells were characterized by quantitative real-time RT-PCR and immunofluorescence. Adhesion of high PAX7 expressing satellite cells was improved if the cells were cultured on fibronectin or laminin coatings. Cells cultured on Matrigel and laminin coatings showed dominant integrin expression levels and exhibited an activated Wnt pathway. Under these conditions both stem cell proliferation and myogenic differentiation capacity were superior if compared to cells cultured on collagen type I, fibronectin and gelatin. In conclusion, Matrigel and laminin are the preferred coatings to sustain the proliferation and myogenic differentiation capacity of the primary porcine muscle stem cells, when cells are removed from their natural environment for in vitro culture.

  2. Extracellular matrix components direct porcine muscle stem cell behavior

    Energy Technology Data Exchange (ETDEWEB)

    Wilschut, Karlijn J. [Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM, Utrecht (Netherlands); Haagsman, Henk P. [Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584 CL, Utrecht (Netherlands); Roelen, Bernard A.J., E-mail: b.a.j.roelen@uu.nl [Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM, Utrecht (Netherlands)

    2010-02-01

    In muscle tissue, extracellular matrix proteins, together with the vasculature system, muscle-residence cells and muscle fibers, create the niche for muscle stem cells. The niche is important in controlling proliferation and directing differentiation of muscle stem cells to sustain muscle tissue. Mimicking the extracellular muscle environment improves tools exploring the behavior of primary muscle cells. Optimizing cell culture conditions to maintain muscle commitment is important in stem cell-based studies concerning toxicology screening, ex vivo skeletal muscle tissue engineering and in the enhancement of clinical efficiency. We used the muscle extracellular matrix proteins collagen type I, fibronectin, laminin, and also gelatin and Matrigel as surface coatings of tissue culture plastic to resemble the muscle extracellular matrix. Several important factors that determine myogenic commitment of the primary muscle cells were characterized by quantitative real-time RT-PCR and immunofluorescence. Adhesion of high PAX7 expressing satellite cells was improved if the cells were cultured on fibronectin or laminin coatings. Cells cultured on Matrigel and laminin coatings showed dominant integrin expression levels and exhibited an activated Wnt pathway. Under these conditions both stem cell proliferation and myogenic differentiation capacity were superior if compared to cells cultured on collagen type I, fibronectin and gelatin. In conclusion, Matrigel and laminin are the preferred coatings to sustain the proliferation and myogenic differentiation capacity of the primary porcine muscle stem cells, when cells are removed from their natural environment for in vitro culture.

  3. Apoptosis by Direct Current Treatment in Tumor Cells and Tissues

    Science.gov (United States)

    Kim, Hongbae; Sim, Sungbo; Ahn, Saeyoung

    2003-10-01

    Electric field induces cell fusion, electroporation on biological cells, including apoptosis. Apoptosis is expressed in a series of natural enzymatic reactions for the natural elimination of unhealthy, genetically damaged, or otherwise aberrant cells that are not needed or not advantageous to the well-being of the organism. Its markers involve cell shrinkage, activation of intracellular caspase proteases, externalization of phosphatidylserine at the plasma membrane, and fragmentation of DNA. Direct electric fields using direct current have been exploited recently to investigate its effects on tumor cells and tissues, but the mechanism of direct electric fields has not been exhibited clearly other than by electroosmosis or pH changes. Direct electric field induces apoptosis in tumor cells cultured and tumor tissues as indicated by cell shrinkage, DNA fragmentation and tumor suppression. In our experiment that direct electric field was applied to tumor tissues via two needle electrodes inserted into tumor tissue 5mm at distance in parallel, pH changes resulted from electrochemical reaction, exhibiting about pH 9.0, 1.83, 2.0 in the vicinity of cathodic and anodic electrode, and at their mid-point, respectively. DNA fragmentation of tumor tissues destructed by direct electric field was analyzed by Tunel assay by ApopTag technology. As a result of this analysis, it showed that apoptosis in tumor tissue destructed was increased up to 59.1normal(control) tissues, showing 41.1, 31.1cathodic tissues. In vitro cell survival was exhibited that it was decreased with enhancing electric current intensity in the same condition of electrical charge 5C having different time applied. We will show results of apoptosis analyzed by flow cytometry in vitro.

  4. Footprints reveal direct evidence of group behavior and locomotion in Homo erectus.

    Science.gov (United States)

    Hatala, Kevin G; Roach, Neil T; Ostrofsky, Kelly R; Wunderlich, Roshna E; Dingwall, Heather L; Villmoare, Brian A; Green, David J; Harris, John W K; Braun, David R; Richmond, Brian G

    2016-01-01

    Bipedalism is a defining feature of the human lineage. Despite evidence that walking on two feet dates back 6-7 Ma, reconstructing hominin gait evolution is complicated by a sparse fossil record and challenges in inferring biomechanical patterns from isolated and fragmentary bones. Similarly, patterns of social behavior that distinguish modern humans from other living primates likely played significant roles in our evolution, but it is exceedingly difficult to understand the social behaviors of fossil hominins directly from fossil data. Footprints preserve direct records of gait biomechanics and behavior but they have been rare in the early human fossil record. Here we present analyses of an unprecedented discovery of 1.5-million-year-old footprint assemblages, produced by 20+ Homo erectus individuals. These footprints provide the oldest direct evidence for modern human-like weight transfer and confirm the presence of an energy-saving longitudinally arched foot in H. erectus. Further, print size analyses suggest that these H. erectus individuals lived and moved in cooperative multi-male groups, offering direct evidence consistent with human-like social behaviors in H. erectus. PMID:27403790

  5. Manipulation of Neutrophil-Like HL-60 Cells for the Study of Directed Cell Migration

    OpenAIRE

    Millius, Arthur; Weiner, Orion D

    2010-01-01

    Many cells undergo directed cell migration in response to external cues in a process known as chemotaxis. This ability is essential for many single-celled organisms to hunt and mate, the development of multicellular organisms, and the functioning of the immune system. Because of their relative ease of manipulation and their robust chemotactic abilities, the neutrophil-like cell line (HL-60) has been a powerful system to analyze directed cell migration. In this chapter, we describe the mainten...

  6. Excitatory Synaptic Inputs to Mouse On-Off Direction-Selective Retinal Ganglion Cells Lack Direction Tuning

    OpenAIRE

    Park, Silvia J.H.; Kim, In-Jung; Loren L Looger; Demb, Jonathan B; Borghuis, Bart G.

    2014-01-01

    Direction selectivity represents a fundamental visual computation. In mammalian retina, On-Off direction-selective ganglion cells (DSGCs) respond strongly to motion in a preferred direction and weakly to motion in the opposite, null direction. Electrical recordings suggested three direction-selective (DS) synaptic mechanisms: DS GABA release during null-direction motion from starburst amacrine cells (SACs) and DS acetylcholine and glutamate release during preferred direction motion from SACs ...

  7. High specific power, direct methanol fuel cell stack

    Science.gov (United States)

    Ramsey, John C.; Wilson, Mahlon S.

    2007-05-08

    The present invention is a fuel cell stack including at least one direct methanol fuel cell. A cathode manifold is used to convey ambient air to each fuel cell, and an anode manifold is used to convey liquid methanol fuel to each fuel cell. Tie-bolt penetrations and tie-bolts are spaced evenly around the perimeter to hold the fuel cell stack together. Each fuel cell uses two graphite-based plates. One plate includes a cathode active area that is defined by serpentine channels connecting the inlet manifold with an integral flow restrictor to the outlet manifold. The other plate includes an anode active area defined by serpentine channels connecting the inlet and outlet of the anode manifold. Located between the two plates is the fuel cell active region.

  8. Direct and Indirect Evidence of Size-Selective Grazing on Pelagic Bacteria by Freshwater Nanoflagellates

    OpenAIRE

    Šimek, Karel; Chrzanowski, Thomas H.

    1992-01-01

    Size-selective grazing of three heterotrophic nanoflagellates (with cell sizes of 21, 44, and 66 μm3) isolated from Lake Arlington, Texas was examined by using a natural mixture of fluorescence labelled lake bacteria. Sizes of ingested bacteria in food vacuoles were directly measured. Larger bacterial cells were ingested at a frequency much higher than that at which they occurred in the assemblage, indicating preferential flagellate grazing on the larger size classes within the lake bacteriop...

  9. Evidence for Direct Geographic Influences on Linguistic Sounds: The Case of Ejectives

    OpenAIRE

    Caleb Everett

    2013-01-01

    We present evidence that the geographic context in which a language is spoken may directly impact its phonological form. We examined the geographic coordinates and elevations of 567 language locations represented in a worldwide phonetic database. Languages with phonemic ejective consonants were found to occur closer to inhabitable regions of high elevation, when contrasted to languages without this class of sounds. In addition, the mean and median elevations of the locations of languages with...

  10. No evidence for directional evolution of body mass in herbivorous theropod dinosaurs

    OpenAIRE

    Zanno, Lindsay E.; Peter J Makovicky

    2013-01-01

    The correlation between large body size and digestive efficiency has been hypothesized to have driven trends of increasing mass in herbivorous clades by means of directional selection. Yet, to date, few studies have investigated this relationship from a phylogenetic perspective, and none, to our knowledge, with regard to trophic shifts. Here, we reconstruct body mass in the three major subclades of non-avian theropod dinosaurs whose ecomorphology is correlated with extrinsic evidence of at le...

  11. First direct evidence of a vertebrate three-level trophic chain in the fossil record

    OpenAIRE

    Kriwet, Jürgen; Witzmann, Florian; Klug, Stefanie; Heidtke, Ulrich H.J

    2007-01-01

    We describe the first known occurrence of a Permian shark specimen preserving two temnospondyl amphibians in its digestive tract as well as the remains of an acanthodian fish, which was ingested by one of the temnospondyls. This exceptional find provides for the first time direct evidence of a vertebrate three-level food chain in the fossil record with the simultaneous preservation of three trophic levels. Our analysis shows that small-sized Lower Permian xenacanthid sharks of the genus Triod...

  12. Economics of Direct Hydrogen Polymer Electrolyte Membrane Fuel Cell Systems

    Energy Technology Data Exchange (ETDEWEB)

    Mahadevan, Kathyayani

    2011-10-04

    Battelle's Economic Analysis of PEM Fuel Cell Systems project was initiated in 2003 to evaluate the technology and markets that are near-term and potentially could support the transition to fuel cells in automotive markets. The objective of Battelle?s project was to assist the DOE in developing fuel cell systems for pre-automotive applications by analyzing the technical, economic, and market drivers of direct hydrogen PEM fuel cell adoption. The project was executed over a 6-year period (2003 to 2010) and a variety of analyses were completed in that period. The analyses presented in the final report include: Commercialization scenarios for stationary generation through 2015 (2004); Stakeholder feedback on technology status and performance status of fuel cell systems (2004); Development of manufacturing costs of stationary PEM fuel cell systems for backup power markets (2004); Identification of near-term and mid-term markets for PEM fuel cells (2006); Development of the value proposition and market opportunity of PEM fuel cells in near-term markets by assessing the lifecycle cost of PEM fuel cells as compared to conventional alternatives used in the marketplace and modeling market penetration (2006); Development of the value proposition of PEM fuel cells in government markets (2007); Development of the value proposition and opportunity for large fuel cell system application at data centers and wastewater treatment plants (2008); Update of the manufacturing costs of PEM fuel cells for backup power applications (2009).

  13. Astrophysical evidence shows no direct interaction between gravitation and electromagnetism in empty vacuum space

    Science.gov (United States)

    Dowdye, Edward H., Jr.

    2009-08-01

    Findings show that important fundamental principles of mathematical Physics are consistently misapplied to concepts of gravitational lensing or just simply ignored. The thin plasma atmosphere of the sun represents an indirect interaction involving an interfering plasma medium between the gravitational field of the sun and the rays of light from the stars. There is convincing observational evidence that a direct interaction between light and gravitation in empty vacuum space is yet to be observed. Historically, the observed evidence of light bending occurred predominantly near the plasma rim of the sun, not in the vacuum space far above the rim. An intense search of the star filled sky will reveal a clear lack of lensing exists among the countless numbers of stars, where the lens and the source are by good chance co-linearly aligned with the earth based observer. With this condition at hand and assuming the validity of the light bending rule of General Relativity, the sky should be filled with images of Einstein rings. Moreover, the events taking place at the center of our galaxy under intense observations by the astrophysicists since 1992, presents convincing evidence that a direct interaction between light and gravitation simply does not take place. This highly studied region, known as Sagittarius A*, is thought to contain a super massive black hole, a most likely candidate for gravitational lensing. The evidence is clearly revealed in the time resolved images of the rapidly moving stellar objects orbiting about Sagittarius A*.

  14. Spatial coordination of cell orientation directed by nanoribbon sheets.

    Science.gov (United States)

    Fujie, Toshinori; Shi, Xuetao; Ostrovidov, Serge; Liang, Xiaobin; Nakajima, Ken; Chen, Yin; Wu, Hongkai; Khademhosseini, Ali

    2015-06-01

    Spatial coordination of cell orientation is of central importance in tissue/organ construction. In this study, we developed microfabricated poly(lactic-co-glycolic acid) (PLGA) nanoribbon sheets with unique structures, using spin-coating and micropatterning techniques, in order to generate a hierarchically assembled cellular structure consisting of murine skeletal myoblasts (C2C12). The nanoribbon sheets were composed of aligned PLGA nanoribbons in the center, and strips on four sides which take a role as bridges to connect and immobilize the aligned nanoribbons. Such unique structures facilitated the alignment of C2C12 cells into bilayer cell sheets, and cellular alignment was directed by the aligned direction of nanoribbons. The nanoribbon sheets also facilitated the construction of multilayer cell sheets with anisotropic (orthogonal) and isotropic (parallel) orientations. The enhanced expression of myogenic genes of C2C12 cells on the bilayer cell sheets demonstrated that the nanoribbons induced C2C12 cell differentiation into mature myoblasts. The micropatterned nanoribbon sheets may be a useful tool for directing cellular organization with defined alignment for regenerative medicine and drug screening applications. PMID:25890709

  15. In vivo evidence for the fibrillar structures of Sup35 prions in yeast cells

    OpenAIRE

    Kawai-Noma, Shigeko; Pack, Chan-Gi; Kojidani, Tomoko; Asakawa, Haruhiko; Hiraoka, Yasushi; Kinjo, Masataka; Haraguchi, Tokuko; Taguchi, Hideki; Hirata, Aiko

    2010-01-01

    Yeast prion [PSI+ ] is caused by aggregated structures of the Sup35 protein. Although Sup35 forms typical amyloid fibrils in vitro, there is no direct evidence for the fibrillar structures of Sup35 in vivo. We analyzed [PSI+ ] cells in which Sup35 fused with green fluorescent protein (GFP) formed aggregates visible by fluorescence microscopy using thin-section electron microscopy (EM). Rapid-freeze EM combined with an immunogold-labeling technique as well as correlative light EM, which allows...

  16. Direct alcohol fuel cells materials, performance, durability and applications

    CERN Document Server

    Corti, Horacio R

    2013-01-01

    Direct Alcohol Fuel Cells: Materials, Performance, Durability and Applications begins with an introductory overview of direct alcohol fuel cells (DAFC); it focuses on the main goals and challenges in the areas of materials development, performance, and commercialization. The preparation and the properties of the anodic catalysts used for the oxidation of methanol, higher alcohols, and alcohol tolerant cathodes are then described. The membranes used as proton conductors in DAFC are examined, as well as alkaline membranes, focusing on the electrical conductivity and alcohol permeability. The use

  17. A Direct DME High Temperature PEM Fuel Cell

    DEFF Research Database (Denmark)

    Vassiliev, Anton; Jensen, Jens Oluf; Li, Qingfeng;

    2012-01-01

    Dimethyl ether (DME) has been identified as an alternative to methanol for use in direct fuel cells. It combines the advantages of hydrogen in terms of pumpless fuel delivery and high energy density like methanol, but without the toxicity of the latter. The performance of a direct dimethyl ether...... fuel cell suffers greatly from the very low DME-water miscibility. To cope with the problem polybenzimidazole (PBI) based membrane electrode assemblies (MEAs) have been made and tested in a vapor fed system. PtRu on carbon has been used as anode catalyst and air at ambient pressure was used as oxidant...

  18. Direct dimethyl ether high temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Vassiliev, Anton; Jensen, Jens Oluf; Li, Qingfeng;

    A high temperature polybenzimidazole (PBI) polymer fuel cell was fed with dimethyl ether (DME) and water vapour mixture on the anode at ambient pressure with air as oxidant. A peak power density of 79 mW/cm2 was achieved at 200°C. A conventional polymer based direct DME fuel cell is liquid fed and...... suffers from low DME solubility in water. When the DME - water mixture is fed as vapour miscibility is no longer a problem. The increased temperature is more beneficial for the kinetics of the direct oxidation of DME than of methanol. The Open Circuit Voltage (OCV) with DME operation was 50 to 100 m...

  19. Enhanced methanol utilization in direct methanol fuel cell

    Science.gov (United States)

    Ren, Xiaoming; Gottesfeld, Shimshon

    2001-10-02

    The fuel utilization of a direct methanol fuel cell is enhanced for improved cell efficiency. Distribution plates at the anode and cathode of the fuel cell are configured to distribute reactants vertically and laterally uniformly over a catalyzed membrane surface of the fuel cell. A conductive sheet between the anode distribution plate and the anodic membrane surface forms a mass transport barrier to the methanol fuel that is large relative to a mass transport barrier for a gaseous hydrogen fuel cell. In a preferred embodiment, the distribution plate is a perforated corrugated sheet. The mass transport barrier may be conveniently increased by increasing the thickness of an anode conductive sheet adjacent the membrane surface of the fuel cell.

  20. Power generation properties of Direct Flame Fuel Cell (DFFC)

    International Nuclear Information System (INIS)

    This paper investigated the effect of cell temperature and product species concentration induced by small-jet flame on the power generation performance of Direct Flame Fuel Cell (DFFC). The cell is placed above the small flame and heated product gas is impinged toward it and this system is the simplest and smallest unit of the power generation device to be developed. Equivalence ratio (φ) and the distance between the cell and the burner surface (d) are considered as main experimental parameters. It turns out that open circuit voltage (OCV) increases linearly with the increase of temperature in wide range of equivalence ratios. However, it increases drastically at which the equivalence ratio became small (φ ≤ 2.0) showing inner flame clearly. This result suggests that OCV depends on not only cell temperature but also the species concentration exposed to the cell. It is suggested that Nernst equation might work satisfactory to predict OCV of DFFC

  1. Dynamic simulation of a direct carbonate fuel cell power plant

    Energy Technology Data Exchange (ETDEWEB)

    Ernest, J.B. [Fluor Daniel, Inc., Irvine, CA (United States); Ghezel-Ayagh, H.; Kush, A.K. [Fuel Cell Engineering, Danbury, CT (United States)

    1996-12-31

    Fuel Cell Engineering Corporation (FCE) is commercializing a 2.85 MW Direct carbonate Fuel Cell (DFC) power plant. The commercialization sequence has already progressed through construction and operation of the first commercial-scale DFC power plant on a U.S. electric utility, the 2 MW Santa Clara Demonstration Project (SCDP), and the completion of the early phases of a Commercial Plant design. A 400 kW fuel cell stack Test Facility is being built at Energy Research Corporation (ERC), FCE`s parent company, which will be capable of testing commercial-sized fuel cell stacks in an integrated plant configuration. Fluor Daniel, Inc. provided engineering, procurement, and construction services for SCDP and has jointly developed the Commercial Plant design with FCE, focusing on the balance-of-plant (BOP) equipment outside of the fuel cell modules. This paper provides a brief orientation to the dynamic simulation of a fuel cell power plant and the benefits offered.

  2. Alkaline direct alcohol fuel cells using an anion exchange membrane

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, Koji; Iriyama, Yasutoshi; Abe, Takeshi; Ogumi, Zempachi [Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan); Matsuoka, Masao [Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577 (Japan)

    2005-10-04

    Alkaline direct alcohol fuel cells using an OH-form anion exchange membrane and polyhydric alcohols were studied. A high open circuit voltage of ca. 800mV was obtained for a cell using Pt-Ru/C (anode) and Pt/C (cathode) at 323K, which was about 100-200mV higher than that for a DMFC using Nafion{sup R}. The maximum power densities were in the order of ethylene glycol>glycerol>methanol>erythritol>xylitol. Silver catalysts were used as a cathode catalyst to fabricate alkaline fuel cells, since silver catalyst is almost inactive in the oxidation of polyhydric alcohols. Alkaline direct ethylene glycol fuel cells using silver as a cathode catalyst gave excellent performance because higher concentrations of fuel could be supplied to the anode. (author)

  3. Chicken pox infection (varicella zoster virus) and acute monoarthritis: evidence against a direct viral mechanism.

    OpenAIRE

    Fink, C G; Read, S J; Giddins, G.; Eglin, R. P.

    1992-01-01

    A 9 year old boy developed acute monoarthritis of the left knee concurrent with the appearance of a varicella zoster virus (VZV) rash. Repeated VZV DNA hybridisation of the cells within the synovial fluid and synovial membrane failed to show any evidence of intracellular virus. Virus was isolated from synovial fluid 24 hours after the start of clinical infection but not later. These findings suggest that the mechanism of the arthritis is not due to viral replication inside the swollen joint.

  4. Astrocytes directly influence tumor cell invasion and metastasis in vivo.

    Directory of Open Access Journals (Sweden)

    Ling Wang

    Full Text Available Brain metastasis is a defining component of tumor pathophysiology, and the underlying mechanisms responsible for this phenomenon are not well understood. Current dogma is that tumor cells stimulate and activate astrocytes, and this mutual relationship is critical for tumor cell sustenance in the brain. Here, we provide evidence that primary rat neonatal and adult astrocytes secrete factors that proactively induced human lung and breast tumor cell invasion and metastasis capabilities. Among which, tumor invasion factors namely matrix metalloprotease-2 (MMP-2 and MMP-9 were partly responsible for the astrocyte media-induced tumor cell invasion. Inhibiting MMPs reduced the ability of tumor cell to migrate and invade in vitro. Further, injection of astrocyte media-conditioned breast cancer cells in mice showed increased invasive activity to the brain and other distant sites. More importantly, blocking the preconditioned tumor cells with broad spectrum MMP inhibitor decreased the invasion and metastasis of the tumor cells, in particular to the brain in vivo. Collectively, our data implicate astrocyte-derived MMP-2 and MMP-9 as critical players that facilitate tumor cell migration and invasion leading to brain metastasis.

  5. Direct evidence of strain transfer for InAs island growth on compliant Si substrates

    Energy Technology Data Exchange (ETDEWEB)

    Marçal, L. A. B.; Magalhães-Paniago, R.; Malachias, Angelo, E-mail: angeloms@fisica.ufmg.br [Universidade Federal de Minas Gerais, Av. Antonio Carlos 6627, CEP 31270-901, Belo Horizonte (Brazil); Richard, M.-I. [European Synchrotron (ESRF), ID01 beamline, CS 40220, 38043 Grenoble Cedex 9 (France); Aix-Marseille University, IM2NP-CNRS, Faculté des Sciences de St Jérôme, 13397 Marseille (France); Cavallo, F. [Center for High Technology Materials, University of New Mexico, 1313 Goddard St., Albuquerque, New Mexico 87106 (United States); University of Wisconsin-Madison, 1500 Engineering Drive, Madison, Wisconsin 53706 (United States); Lagally, M. G. [University of Wisconsin-Madison, 1500 Engineering Drive, Madison, Wisconsin 53706 (United States); Schmidt, O. G. [Institute for Integrative Nanosciences, IFW-Dresden, D-01171 Dresden (Germany); Schülli, T. Ü. [European Synchrotron (ESRF), ID01 beamline, CS 40220, 38043 Grenoble Cedex 9 (France); Deneke, Ch. [Laboratório Nacional de Nanotecnologia (LNNano/CNPEM), C.P. 6192, CEP 13083-970, Campinas (Brazil)

    2015-04-13

    Semiconductor heteroepitaxy on top of thin compliant layers has been explored as a path to make inorganic electronics mechanically flexible as well as to integrate materials that cannot be grown directly on rigid substrates. Here, we show direct evidences of strain transfer for InAs islands on freestanding Si thin films (7 nm). Synchrotron X-ray diffraction measurements using a beam size of 300 × 700 nm{sup 2} can directly probe the strain status of the compliant substrate underneath deposited islands. Using a recently developed diffraction mapping technique, three-dimensional reciprocal space maps were reconstructed around the Si (004) peak for specific illuminated positions of the sample. The strain retrieved was analyzed using continuous elasticity theory via Finite-element simulations. The comparison of experiment and simulations yields the amount of strain from the InAs islands, which is transferred to the compliant Si thin film.

  6. Direct evidence of strain transfer for InAs island growth on compliant Si substrates

    International Nuclear Information System (INIS)

    Semiconductor heteroepitaxy on top of thin compliant layers has been explored as a path to make inorganic electronics mechanically flexible as well as to integrate materials that cannot be grown directly on rigid substrates. Here, we show direct evidences of strain transfer for InAs islands on freestanding Si thin films (7 nm). Synchrotron X-ray diffraction measurements using a beam size of 300 × 700 nm2 can directly probe the strain status of the compliant substrate underneath deposited islands. Using a recently developed diffraction mapping technique, three-dimensional reciprocal space maps were reconstructed around the Si (004) peak for specific illuminated positions of the sample. The strain retrieved was analyzed using continuous elasticity theory via Finite-element simulations. The comparison of experiment and simulations yields the amount of strain from the InAs islands, which is transferred to the compliant Si thin film

  7. Direct evidence for the atovaquone action on the Plasmodium cytochrome bc1 complex.

    Science.gov (United States)

    Siregar, Josephine E; Kurisu, Genji; Kobayashi, Tamaki; Matsuzaki, Motomichi; Sakamoto, Kimitoshi; Mi-ichi, Fumika; Watanabe, Yoh-ichi; Hirai, Makoto; Matsuoka, Hiroyuki; Syafruddin, Din; Marzuki, Sangkot; Kita, Kiyoshi

    2015-06-01

    Atovaquone, a coenzyme Q analogue has been indicated to specifically target the cytochrome bc1 complex of the mitochondrial respiratory chain in the malarial parasite and other protozoan. Various mutations in the quinone binding site of the cytochrome b gene of Plasmodium spp. such as M133I, L144S, L271V, K272R, Y268C, Y268S, Y268N, and V284F are suggesting to associate with resistance to atovaquone. There is no direct evidence of relation between the mutations and resistance to atovaquone in Plasmodium parasite that has been available. Technical difficulties in isolating active assayable mitochondria in the malarial parasite hinder us to obtain direct biochemical evidence to support the relation between the mutations and drug resistance. The establishment of a mitochondrial isolation method for the malaria parasite has allowed us to test the degree of resistance of Plasmodium berghei isolates to atovaquone directly. We have tested the activity of dihydroorotate (DHO)-cytochrome c reductase in various P. berghei atovaquone resistant clones in the presence of a wide concentration range of atovaquone. Our results show the IC(50) of P. berghei atovaquone resistant clones is much higher (1.5 up to 40 nM) in comparison to the atovaquone sensitive clones (0.132-0.465 nM). The highest IC(50) was revealed in clones carrying Y268C and Y268N mutations (which play an important role in atovaquone resistance in Plasmodium falciparum), with an approximately 100-fold increase. The findings indicate the importance of the mutation in the quinone binding site of the cytochrome b gene and that provide a direct evidence for the atovaquone inhibitory mechanism in the cytochrome bc1 complex of the parasite. PMID:25264100

  8. Cell carriers for oncolytic viruses: current challenges and future directions.

    Science.gov (United States)

    Roy, Dominic G; Bell, John C

    2013-01-01

    The optimal route for clinical delivery of oncolytic viruses is thought to be systemic intravenous injection; however, the immune system is armed with several highly efficient mechanisms to remove pathogens from the circulatory system. To overcome the challenges faced in trying to delivery oncolytic viruses specifically to tumors via the bloodstream, carrier cells have been investigated to determine their suitability as delivery vehicles for systemic administration of oncolytic viruses. Cell carriers protect viruses from neutralization, one of the most limiting aspects of oncolytic virus interaction with the immune system. Cell carriers can also possess inherent tumor tropism, thus directing the delivery of the virus more specifically to a tumor. With preclinical studies already demonstrating the success and feasibility of this approach with multiple oncolytic viruses, clinical evaluation of cell-mediated delivery of viruses is on the horizon. Meanwhile, ongoing preclinical studies are aimed at identifying new cellular vehicles for oncolytic viruses and improving current promising cell carrier platforms. PMID:27512657

  9. Directed neuronal differentiation of human embryonic stem cells

    Directory of Open Access Journals (Sweden)

    Noggle Scott A

    2003-10-01

    Full Text Available Abstract Background We have developed a culture system for the efficient and directed differentiation of human embryonic stem cells (HESCs to neural precursors and neurons. HESC were maintained by manual passaging and were differentiated to a morphologically distinct OCT-4+/SSEA-4- monolayer cell type prior to the derivation of embryoid bodies. Embryoid bodies were grown in suspension in serum free conditions, in the presence of 50% conditioned medium from the human hepatocarcinoma cell line HepG2 (MedII. Results A neural precursor population was observed within HESC derived serum free embryoid bodies cultured in MedII conditioned medium, around 7–10 days after derivation. The neural precursors were organized into rosettes comprised of a central cavity surrounded by ring of cells, 4 to 8 cells in width. The central cells within rosettes were proliferating, as indicated by the presence of condensed mitotic chromosomes and by phosphoHistone H3 immunostaining. When plated and maintained in adherent culture, the rosettes of neural precursors were surrounded by large interwoven networks of neurites. Immunostaining demonstrated the expression of nestin in rosettes and associated non-neuronal cell types, and a radial expression of Map-2 in rosettes. Differentiated neurons expressed the markers Map-2 and Neurofilament H, and a subpopulation of the neurons expressed tyrosine hydroxylase, a marker for dopaminergic neurons. Conclusion This novel directed differentiation approach led to the efficient derivation of neuronal cultures from HESCs, including the differentiation of tyrosine hydroxylase expressing neurons. HESC were morphologically differentiated to a monolayer OCT-4+ cell type, which was used to derive embryoid bodies directly into serum free conditions. Exposure to the MedII conditioned medium enhanced the derivation of neural precursors, the first example of the effect of this conditioned medium on HESC.

  10. Cell order in bacterial swarms arises from reversals of moving direction

    Science.gov (United States)

    Wu, Yilin; Jiang, Yi; Kaiser, Dale; Alber, Mark

    2010-03-01

    Bacterial swarms are a beautiful example of the emergent behavior of systems of self-propelled rods. In swarming rod-shaped bacteria cells move smoothly even though they are packed together in high density. Experimental evidence shows that long-distance signaling is not required for bacterial swarming. It naturally raises the question how a swarm develops its order. Using a biomechanical model, we show here that regular periodic reversals of gliding direction in general systems of self-propelled rod shaped bacteria can lead to the extensive ordering of cells. We also show that an optimal reversal period and an optimal cell shape exist for producing such order. Given the observations of reversing behavior in several bacterial species,we suggest that the capacity to swarm depends less on the motility engine employed by individual cells, but more on the behavioral algorithm that enhances the flow of densely packed cells near the swarming edge.

  11. IL-12 directs further maturation of ex vivo differentiated NK cells with improved therapeutic potential.

    Directory of Open Access Journals (Sweden)

    Dorit Lehmann

    Full Text Available The possibility to modulate ex vivo human NK cell differentiation towards specific phenotypes will contribute to a better understanding of NK cell differentiation and facilitate tailored production of NK cells for immunotherapy. In this study, we show that addition of a specific low dose of IL-12 to an ex vivo NK cell differentiation system from cord blood CD34(+ stem cells will result in significantly increased proportions of cells with expression of CD62L as well as KIRs and CD16 which are preferentially expressed on mature CD56(dim peripheral blood NK cells. In addition, the cells displayed decreased expression of receptors such as CCR6 and CXCR3, which are typically expressed to a lower extent by CD56(dim than CD56(bright peripheral blood NK cells. The increased number of CD62L and KIR positive cells prevailed in a population of CD33(+NKG2A(+ NK cells, supporting that maturation occurs via this subtype. Among a series of transcription factors tested we found Gata3 and TOX to be significantly downregulated, whereas ID3 was upregulated in the IL-12-modulated ex vivo NK cells, implicating these factors in the observed changes. Importantly, the cells differentiated in the presence of IL-12 showed enhanced cytokine production and cytolytic activity against MHC class I negative and positive targets. Moreover, in line with the enhanced CD16 expression, these cells exhibited improved antibody-dependent cellular cytotoxicity for B-cell leukemia target cells in the presence of the clinically applied antibody rituximab. Altogether, these data provide evidence that IL-12 directs human ex vivo NK cell differentiation towards more mature NK cells with improved properties for potential cancer therapies.

  12. Silencing of directional migration in roundabout4 knockdown endothelial cells

    Directory of Open Access Journals (Sweden)

    Roberts David D

    2008-11-01

    Full Text Available Abstract Background Roundabouts are axon guidance molecules that have recently been identified to play a role in vascular guidance as well. In this study, we have investigated gene knockdown analysis of endothelial Robos, in particular roundabout 4 (robo4, the predominant Robo in endothelial cells using small interfering RNA technology in vitro. Results Robo1 and Robo4 knockdown cells display distinct activity in endothelial cell migration assay. The knockdown of robo4 abrogated the chemotactic response of endothelial cells to serum but enhanced a chemokinetic response to Slit2, while robo1 knockdown cells do not display chemotactic response to serum or VEGF. Robo4 knockdown endothelial cells unexpectedly show up regulation of Rho GTPases. Zebrafish Robo4 rescues both Rho GTPase homeostasis and serum reduced chemotaxis in robo4 knockdown cells. Robo1 and Robo4 interact and share molecules such as Slit2, Mena and Vilse, a Cdc42-GAP. In addition, this study mechanistically implicates IRSp53 in the signaling nexus between activated Cdc42 and Mena, both of which have previously been shown to be involved with Robo4 signaling in endothelial cells. Conclusion This study identifies specific components of the Robo signaling apparatus that work together to guide directional migration of endothelial cells.

  13. Direct Visualization of De novo Lipogenesis in Single Living Cells

    Science.gov (United States)

    Li, Junjie; Cheng, Ji-Xin

    2014-10-01

    Increased de novo lipogenesis is being increasingly recognized as a hallmark of cancer. Despite recent advances in fluorescence microscopy, autoradiography and mass spectrometry, direct observation of de novo lipogenesis in living systems remains to be challenging. Here, by coupling stimulated Raman scattering (SRS) microscopy with isotope labeled glucose, we were able to trace the dynamic metabolism of glucose in single living cells with high spatial-temporal resolution. As the first direct visualization, we observed that glucose was largely utilized for lipid synthesis in pancreatic cancer cells, which occurs at a much lower rate in immortalized normal pancreatic epithelial cells. By inhibition of glycolysis and fatty acid synthase (FAS), the key enzyme for fatty acid synthesis, we confirmed the deuterium labeled lipids in cancer cells were from de novo lipid synthesis. Interestingly, we also found that prostate cancer cells exhibit relatively lower level of de novo lipogenesis, but higher fatty acid uptake compared to pancreatic cancer cells. Together, our results demonstrate a valuable tool to study dynamic lipid metabolism in cancer and other disorders.

  14. Direct effect of bevacizumab on glioblastoma cell lines in vitro.

    Science.gov (United States)

    Simon, Thomas; Coquerel, Bérénice; Petit, Alexandre; Kassim, Yusra; Demange, Elise; Le Cerf, Didier; Perrot, Valérie; Vannier, Jean-Pierre

    2014-12-01

    Bevacizumab is a humanized monoclonal antibody directed against the pro-angiogenic factor vascular and endothelial growth factor-A (VEGF-A) used in the treatment of glioblastomas. Although most patients respond initially to this treatment, studies have shown that glioblastomas eventually recur. Several non-mutually exclusive theories based on the anti-angiogenic effect of bevacizumab have been proposed to explain these mechanisms of resistance. In this report, we studied whether bevacizumab can act directly on malignant glioblastoma cells. We observe changes in the expression profiles of components of the VEGF/VEGF-R pathway and in the response to a VEGF-A stimulus following bevacizumab treatment. In addition, we show that bevacizumab itself acts on glioblastoma cells by activating the Akt and Erks survival signaling pathways. Bevacizumab also enhances proliferation and invasiveness of glioblastoma cells in hyaluronic acid hydrogel. We propose that the paradoxical effect of bevacizumab on glioblastoma cells could be due to changes in the VEGF-A-dependent autocrine loop as well as in the intracellular survival pathways, leading to the enhancement of tumor aggressiveness. Investigation of how bevacizumab interacts with glioblastoma cells and the resulting downstream signaling pathways will help targeting populations of resistant glioblastoma cells. PMID:25113866

  15. Evidence for breathing modes in direct current, pulsed, and high power impulse magnetron sputtering plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yuchen [State Key Lab for Materials Processing and Die & Mold Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Zhou, Xue [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Department of Electrical Engineering, Harbin Institute of Technology, Harbin 150000 (China); Liu, Jason X. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Department of Physics, University of California, Berkeley, Berkeley, California 94720 (United States); Anders, André, E-mail: aanders@lbl.gov [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)

    2016-01-18

    We present evidence for breathing modes in magnetron sputtering plasmas: periodic axial variations of plasma parameters with characteristic frequencies between 10 and 100 kHz. A set of azimuthally distributed probes shows synchronous oscillations of the floating potential. They appear most clearly when considering the intermediate current regime in which the direction of azimuthal spoke motion changes. Breathing oscillations were found to be superimposed on azimuthal spoke motion. Depending on pressure and current, one can also find a regime of chaotic fluctuations and one of stable discharges, the latter at high current. A pressure-current phase diagram for the different situations is proposed.

  16. Evidence for breathing modes in direct current, pulsed, and high power impulse magnetron sputtering plasmas

    International Nuclear Information System (INIS)

    We present evidence for breathing modes in magnetron sputtering plasmas: periodic axial variations of plasma parameters with characteristic frequencies between 10 and 100 kHz. A set of azimuthally distributed probes shows synchronous oscillations of the floating potential. They appear most clearly when considering the intermediate current regime in which the direction of azimuthal spoke motion changes. Breathing oscillations were found to be superimposed on azimuthal spoke motion. Depending on pressure and current, one can also find a regime of chaotic fluctuations and one of stable discharges, the latter at high current. A pressure-current phase diagram for the different situations is proposed

  17. Direct evidence for compressive elastic strain at ground surfaces of nanocomposite ceramics

    International Nuclear Information System (INIS)

    High-resolution grazing incidence x-ray powder diffraction has been used to provide direct evidence for the existence of a uniform compressive strain close to the surface of ground alumina/SiC nanocomposites. No such strain is found in ground surfaces of single-phase alumina or polished surfaces of nanocomposite. The strain in the ground nanocomposite is found to be perpendicular to the grinding direction and disappears on annealing at 1250 deg. C. Such a compressive stress provides a mechanism for enhancing the strength of the nanocomposite, by opposing any tensile loading tending to open surface flaws. The origin of the stresses probably lies in the enhanced grain boundary strength in the nanocomposite alumina-silicon carbide compared to alumina

  18. Direct evidence for compressive elastic strain at ground surfaces of nanocomposite ceramics

    Science.gov (United States)

    Tanner, B. K.; Wu, H. Z.; Roberts, S. G.

    2005-02-01

    High-resolution grazing incidence x-ray powder diffraction has been used to provide direct evidence for the existence of a uniform compressive strain close to the surface of ground alumina/SiC nanocomposites. No such strain is found in ground surfaces of single-phase alumina or polished surfaces of nanocomposite. The strain in the ground nanocomposite is found to be perpendicular to the grinding direction and disappears on annealing at 1250°C. Such a compressive stress provides a mechanism for enhancing the strength of the nanocomposite, by opposing any tensile loading tending to open surface flaws. The origin of the stresses probably lies in the enhanced grain boundary strength in the nanocomposite alumina-silicon carbide compared to alumina.

  19. Pt -based anode catalysts for direct ethanol fuel cells

    International Nuclear Information System (INIS)

    In this work it is studied the electro-catalytic behavior of pure platinum and platinum-based alloys with Ru, Sn, Ir, and Os supported on carbon to the ethanol electro-oxidation in aims to develop anodic catalysts for direct ethanol fuel cells, additionally, porous electrodes and membrane electrode assemblies were built for proton exchange membrane fuel cells in which the electrodes were tested. Catalysts characterization was made by cyclic voltammetry whereas the fuel cells behavior tests were made by current-potential polarization curves. in general, all alloys show a lower on-set reaction potential and a higher catalytic activity than pure platinum. However, in the high over potential zone, pure platinum has higher catalytic activity than the alloys. In agreement with these results, the alloys studied here could be useful in fuel cells operating on moderated and low current

  20. Chondromodulin-1 directly suppresses growth of human cancer cells

    International Nuclear Information System (INIS)

    Chondromodulin-1 (ChM1), an endogenous anti-angiogenic factor expressed in cartilage, has been suggested to inhibit invasion of endothelial cells into cartilage. In addition, the ectopic administration of ChM1 has been reported to suppress tumorigenesis in vivo. However, it is unclear whether the anti-tumor effect is due to not only the anti-vascularization effect of ChM1, but also its direct action against oncocytes. In the present study, we sought to determine whether ChM1 has a direct action on tumor cells. BrdU incorporation assay was performed on human umbilical vein endothelial cells (HUVECs), normal human dermal fibroblasts (NHDFs), HepG2 cells and HeLa cells in the presence or absence of recombinant human ChM1 (rhChM1). An adenovirus that expresses ChM1, Ad-ChM1, was established and applied to the tumor xenografted in vivo, and to in vitro tumor cells cultured on plates or in soft agar. Cell cycle-related proteins and the phosphorylation of Erk, Akt, and GSK3β, the downstream molecules of the extracellular matrix-integrin signaling pathways, in HepG2 cells treated with or without Ad-ChM1 were detected by western blot analysis. Luciferase reporter assays of STAT, GAS, and ISRE, which participate in another cytokine signaling pathway, ware performed in HepG2, HeLa, and HUVEC cells. ChM1 suppressed BrdU incorporation in HUVECs and in HepG2 cells dose-dependently, but did not suppress BrdU incorporation in NHDFs and HeLa cells cultured on plates. In soft agar, however, ChM1 suppressed the growth of HeLa cells, as well as HepG2 cells. Western blot analyses demonstrated that ChM1 decreased the levels of cyclin D1, cyclin D3, and cdk6 and increased those of p21cip1 without affecting the phosphorylation levels of Erk, Akt, and GSK3β in HepG2 cells. The luciferase reporter assay demonstrated that ChM1 suppressed the transcriptional activities of STAT and GAS but not of ISRE. ChM1 directly suppressed the proliferation of tumor cells in an anchorage

  1. Direct Coal Oxidation in Modified Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Gil, Vanesa; Ippolito, Davide;

    2015-01-01

    Hybrid direct carbon fuel cells employ a classical solid oxide fuel cell together with carbon dispersed in a carbonate melt on the anode side. In a European project, the utilization of various coals has been investigated with and without addition of an oxidation catalyst to the carbon......-carbonate slurry or anode layer. The nature of the coal affects both open circuit voltage and power output. Highest OCV and power densities were observed for bituminous coal and by adding manganese oxide or praseodymium-doped ceria to the carbon/carbonate mixture. Comparing the carbon black fueled performance of...

  2. Tunable directivity in metamaterials with reconfigurable cell symmetry

    Science.gov (United States)

    Celli, Paolo; Gonella, Stefano

    2015-03-01

    We introduce a strategy to attain reconfigurable, highly focused, subwavelength wave patterns in cellular metamaterials via electromechanical tuning of their microstructures. The metamaterial cells feature a population of auxiliary microstructural elements instrumented with piezoelectric patches connected to negative capacitance shunting circuits. By tuning the circuital characteristics of selected subsets of shunts, we relax the symmetry of the cell material property landscape, thus affecting the global directivity and enabling a plethora of wave manipulation capabilities. The acoustic reconfiguration is decoupled from other mechanical functions and is carried out without affecting the shape or the static properties of the host cellular structure.

  3. Social network analysis shows direct evidence for social transmission of tool use in wild chimpanzees.

    Directory of Open Access Journals (Sweden)

    Catherine Hobaiter

    2014-09-01

    Full Text Available Social network analysis methods have made it possible to test whether novel behaviors in animals spread through individual or social learning. To date, however, social network analysis of wild populations has been limited to static models that cannot precisely reflect the dynamics of learning, for instance, the impact of multiple observations across time. Here, we present a novel dynamic version of network analysis that is capable of capturing temporal aspects of acquisition--that is, how successive observations by an individual influence its acquisition of the novel behavior. We apply this model to studying the spread of two novel tool-use variants, "moss-sponging" and "leaf-sponge re-use," in the Sonso chimpanzee community of Budongo Forest, Uganda. Chimpanzees are widely considered the most "cultural" of all animal species, with 39 behaviors suspected as socially acquired, most of them in the domain of tool-use. The cultural hypothesis is supported by experimental data from captive chimpanzees and a range of observational data. However, for wild groups, there is still no direct experimental evidence for social learning, nor has there been any direct observation of social diffusion of behavioral innovations. Here, we tested both a static and a dynamic network model and found strong evidence that diffusion patterns of moss-sponging, but not leaf-sponge re-use, were significantly better explained by social than individual learning. The most conservative estimate of social transmission accounted for 85% of observed events, with an estimated 15-fold increase in learning rate for each time a novice observed an informed individual moss-sponging. We conclude that group-specific behavioral variants in wild chimpanzees can be socially learned, adding to the evidence that this prerequisite for culture originated in a common ancestor of great apes and humans, long before the advent of modern humans.

  4. Social network analysis shows direct evidence for social transmission of tool use in wild chimpanzees.

    Science.gov (United States)

    Hobaiter, Catherine; Poisot, Timothée; Zuberbühler, Klaus; Hoppitt, William; Gruber, Thibaud

    2014-09-01

    Social network analysis methods have made it possible to test whether novel behaviors in animals spread through individual or social learning. To date, however, social network analysis of wild populations has been limited to static models that cannot precisely reflect the dynamics of learning, for instance, the impact of multiple observations across time. Here, we present a novel dynamic version of network analysis that is capable of capturing temporal aspects of acquisition--that is, how successive observations by an individual influence its acquisition of the novel behavior. We apply this model to studying the spread of two novel tool-use variants, "moss-sponging" and "leaf-sponge re-use," in the Sonso chimpanzee community of Budongo Forest, Uganda. Chimpanzees are widely considered the most "cultural" of all animal species, with 39 behaviors suspected as socially acquired, most of them in the domain of tool-use. The cultural hypothesis is supported by experimental data from captive chimpanzees and a range of observational data. However, for wild groups, there is still no direct experimental evidence for social learning, nor has there been any direct observation of social diffusion of behavioral innovations. Here, we tested both a static and a dynamic network model and found strong evidence that diffusion patterns of moss-sponging, but not leaf-sponge re-use, were significantly better explained by social than individual learning. The most conservative estimate of social transmission accounted for 85% of observed events, with an estimated 15-fold increase in learning rate for each time a novice observed an informed individual moss-sponging. We conclude that group-specific behavioral variants in wild chimpanzees can be socially learned, adding to the evidence that this prerequisite for culture originated in a common ancestor of great apes and humans, long before the advent of modern humans. PMID:25268798

  5. Emerging Evidence for Platelets as Immune and Inflammatory Effector Cells

    Directory of Open Access Journals (Sweden)

    Matthew Thomas Rondina

    2014-12-01

    Full Text Available While traditionally recognized for their roles in hemostatic pathways, emerging evidence demonstrates that platelets have previously unrecognized, dynamic roles that span the immune continuum. These newly-recognized platelet functions, including the secretion of immune mediators, interactions with endothelial cells, monocytes, and neutrophils, toll-like receptor (TLR mediated responses, and induction of neutrophil extracellular trap (NET formation, bridge thrombotic and inflammatory pathways and contribute to host defense mechanisms against invading pathogens. In this focused review, we highlight several of these emerging aspects of platelet biology and their implications in clinical infectious syndromes.

  6. Evidence for a direct involvement of hMSH5 in promoting ionizing radiation induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Tompkins, Joshua D.; Wu, Xiling; Chu, Yen-Lin [School of Molecular Biosciences and Center for Reproductive Biology, PO Box 644660, Washington State University, Pullman, WA 99164-4660 (United States); Her, Chengtao, E-mail: cher@wsu.edu [School of Molecular Biosciences and Center for Reproductive Biology, PO Box 644660, Washington State University, Pullman, WA 99164-4660 (United States)

    2009-08-15

    Although increasing evidence has suggested that the hMSH5 protein plays an important role in meiotic and mitotic DNA recombinational repair, its precise functions in recombination and DNA damage response are presently elusive. Here we show that the interaction between hMSH5 and c-Abl confers ionizing radiation (IR)-induced apoptotic response by promoting c-Abl activation and p73 accumulation, and these effects are greatly enhanced in cells expressing hMSH5{sup P29S} (i.e. the hMSH5 variant possessing a proline to serine change within the N-terminal (Px){sub 5} dipeptide repeat). Our current study provides the first evidence that the (Px){sub 5} dipeptide repeat plays an important role in modulating the interaction between hMSH5 and c-Abl and alteration of this dipeptide repeat in hMSH5{sup P29S} leads to increased IR sensitivity owing to enhanced caspase-3-mediated apoptosis. In addition, RNAi-mediated hMSH5 silencing leads to the reduction of apoptosis in IR-treated cells. In short, this study implicates a role for hMSH5 in DNA damage response involving c-Abl and p73, and suggests that mutations impairing this process could significantly affect normal cellular responses to anti-cancer treatments.

  7. Directed cell migration in the presence of obstacles

    Directory of Open Access Journals (Sweden)

    Grima Ramon

    2007-01-01

    Full Text Available Abstract Background Chemotactic movement is a common feature of many cells and microscopic organisms. In vivo, chemotactic cells have to follow a chemotactic gradient and simultaneously avoid the numerous obstacles present in their migratory path towards the chemotactic source. It is not clear how cells detect and avoid obstacles, in particular whether they need a specialized biological mechanism to do so. Results We propose that cells can sense the presence of obstacles and avoid them because obstacles interfere with the chemical field. We build a model to test this hypothesis and find that this naturally enables efficient at-a-distance sensing to be achieved with no need for a specific and active obstacle-sensing mechanism. We find that (i the efficiency of obstacle avoidance depends strongly on whether the chemotactic chemical reacts or remains unabsorbed at the obstacle surface. In particular, it is found that chemotactic cells generally avoid absorbing barriers much more easily than non-absorbing ones. (ii The typically low noise in a cell's motion hinders the ability to avoid obstacles. We also derive an expression estimating the typical distance traveled by chemotactic cells in a 3D random distribution of obstacles before capture; this is a measure of the distance over which chemotaxis is viable as a means of directing cells from one point to another in vivo. Conclusion Chemotactic cells, in many cases, can avoid obstacles by simply following the spatially perturbed chemical gradients around obstacles. It is thus unlikely that they have developed specialized mechanisms to cope with environments having low to moderate concentrations of obstacles.

  8. Dkk-1 Inhibits Intestinal Epithelial Cell Migration by Attenuating Directional Polarization of Leading Edge Cells

    OpenAIRE

    Koch, Stefan; Capaldo, Christopher T.; Samarin, Stanislav; Nava, Porfirio; Neumaier, Irmgard; Skerra, Arne; Sacks, David B; Parkos, Charles A.; Nusrat, Asma

    2009-01-01

    Wnt signaling pathways regulate proliferation, motility, and survival in a variety of human cell types. Dickkopf-1 (Dkk-1) is a secreted Wnt antagonist that has been proposed to regulate tissue homeostasis in the intestine. In this report, we show that Dkk-1 is secreted by intestinal epithelial cells after wounding and that it inhibits cell migration by attenuating the directional orientation of migrating epithelial cells. Dkk-1 exposure induced mislocalized activation of Cdc42 in migrating c...

  9. Cell carriers for oncolytic viruses: current challenges and future directions

    Directory of Open Access Journals (Sweden)

    Roy DG

    2013-10-01

    Full Text Available Dominic G Roy,1,2 John C Bell1–31Centre for Innovative Cancer Therapeutics, Ottawa Hospital Research Institute, 2Department of Biochemistry, Immunology and Microbiology, 3Department of Medicine, University of Ottawa, Ottawa, ON, CanadaAbstract: The optimal route for clinical delivery of oncolytic viruses is thought to be systemic intravenous injection; however, the immune system is armed with several highly efficient mechanisms to remove pathogens from the circulatory system. To overcome the challenges faced in trying to delivery oncolytic viruses specifically to tumors via the bloodstream, carrier cells have been investigated to determine their suitability as delivery vehicles for systemic administration of oncolytic viruses. Cell carriers protect viruses from neutralization, one of the most limiting aspects of oncolytic virus interaction with the immune system. Cell carriers can also possess inherent tumor tropism, thus directing the delivery of the virus more specifically to a tumor. With preclinical studies already demonstrating the success and feasibility of this approach with multiple oncolytic viruses, clinical evaluation of cell-mediated delivery of viruses is on the horizon. Meanwhile, ongoing preclinical studies are aimed at identifying new cellular vehicles for oncolytic viruses and improving current promising cell carrier platforms.Keywords: oncolytic virus, cell carrier, systemic delivery, tumor targeting, cancer

  10. Biologically-directed modeling reflects cytolytic clearance of SIV-infected cells in vivo in macaques.

    Directory of Open Access Journals (Sweden)

    W David Wick

    Full Text Available The disappointing outcomes of cellular immune-based vaccines against HIV-1 despite strong evidence for the protective role of CD8⁺ T lymphocytes (CTLs has prompted revisiting the mechanisms of cellular immunity. Prior data from experiments examining the kinetics of Simian Immunodeficiency Virus (SIV clearance in infected macaques with or without in vivo CD8 depletion were interpreted as refuting the concept that CTLs suppress SIV/HIV by direct killing of infected cells. Here we briefly review the biological evidence for CTL cytolytic activity in viral infections, and utilize biologically-directed modeling to assess the possibility of a killing mechanism for the antiviral effect of CTLs, taking into account the generation, proliferation, and survival of activated CD4⁺ and CD8⁺ T lymphocytes, as well as the life cycle of the virus. Our analyses of the published macaque data using these models support a killing mechanism, when one considers T lymphocyte and HIV-1 lifecycles, and factors such as the eclipse period before release of virions by infected cells, an exponential pattern of virion production by infected cells, and a variable lifespan for acutely infected cells. We conclude that for SIV/HIV pathogenesis, CTLs deserve their reputation as being cytolytic.

  11. Low contaminant formic acid fuel for direct liquid fuel cell

    Science.gov (United States)

    Masel, Richard I.; Zhu, Yimin; Kahn, Zakia; Man, Malcolm

    2009-11-17

    A low contaminant formic acid fuel is especially suited toward use in a direct organic liquid fuel cell. A fuel of the invention provides high power output that is maintained for a substantial time and the fuel is substantially non-flammable. Specific contaminants and contaminant levels have been identified as being deleterious to the performance of a formic acid fuel in a fuel cell, and embodiments of the invention provide low contaminant fuels that have improved performance compared to known commercial bulk grade and commercial purified grade formic acid fuels. Preferred embodiment fuels (and fuel cells containing such fuels) including low levels of a combination of key contaminants, including acetic acid, methyl formate, and methanol.

  12. Catalytic polymeric electrodes for direct borohydride fuel cells

    Science.gov (United States)

    Bayatsarmadi, Bita; Peters, Alice; Talemi, Pejman

    2016-08-01

    The direct borohydride fuel cell (DBFC) is a new class of fuel cells that produces non-toxic by-products and has a potential for a high voltage and high energy density. A major challenge in developing efficient DBFCs is the development of an efficient, stable, and economic catalyst for the oxidation of borohydride. In this paper, we report the use of conducting polymer Poly(3,4-ethylenedioxythiophene) (PEDOT) as electrocatalysts in DBFC. PEDOT electrodes prepared by vacuum phase polymerization exhibited electrocatalytic behavior towards oxidation of borohydride and reduction of hydrogen peroxide. Spectroscopic analysis of samples showed that PEDOT can act as an interface for electron transfer from borohydride ions. Comparing the polarization curves of DBFCs with PEDOT coated on graphite electrodes and cells with bare graphite electrodes, demonstrated higher voltage, maximum power density, and stability.

  13. Liquid Tin Anode Direct Coal Fuel Cell Final Program Report

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Thomas

    2012-01-26

    This SBIR program will result in improved LTA cell technology which is the fundamental building block of the Direct Coal ECL concept. As described below, ECL can make enormous efficiency and cost contributions to utility scale coal power. This program will improve LTA cells for small scale power generation. As described in the Commercialization section, there are important intermediate military and commercial markets for LTA generators that will provide an important bridge to the coal power application. The specific technical information from this program relating to YSZ electrolyte durability will be broadly applicable SOFC developers working on coal based SOFC generally. This is an area about which very little is currently known and will be critical for successfully applying fuel cells to coal power generation.

  14. Evidence for a direct action of Tityus serrulatus scorpion venom on the cardiac muscle.

    Science.gov (United States)

    Teixeira, A L; Fontoura, B F; Freire-Maia, L; Machado, C R; Camargos, E R; Teixeira, M M

    2001-05-01

    The ability of toxins to activate the cardiovascular system plays an important role in the morbidity and lethality of the Tityus serrulatus scorpion envenoming. Most of the actions of the scorpion toxins are indirect and due to the release of adrenergic and cholinergic neurotransmitters. Accordingly, treatment following envenoming is targeted towards inhibition of adrenergic and cholinergic receptors. Here, we have sought evidence for a direct action of T. serrulatus venom on the isolated rat heart (Langendorff's method). We show that the bradycardia induced by T. serrulatus venom was completely blocked by atropine, a muscarinic receptor antagonist. Similarly, the increase in heart rate that follows the venom-induced bradycardia was totally inhibited by a beta(1)-adrenoceptor antagonist or by chemical sympathetic denervation with 6-hydroxydopamine. In contrast to these findings, the venom-induced increase in contractile force was not modified by beta(1)-adrenoceptor blockade or by chemical sympathetic denervation. The results clearly demonstrate that the chronotropic effects of T. serrulatus are dependent on neurotransmitter release, but the inotropic effects are not. The neurotransmitter-independent increase in contractility seems to be a direct action of the venom on cardiomyocytes. We suggest that this direct effect on cardiac fibers may play a role in the development of cardiac arrhythmias and contractility defects following envenoming with T. serrulatus scorpion. PMID:11072050

  15. The differentiation directions of the bone marrow stromal cells under modeling microgravity

    Science.gov (United States)

    Nesterenko, Olga; Rodionova, Natalia; Katkova, Olena

    Within experiments on rats simulating microgravity by base load remove from back limbs (duration of the experiment 1,5 months) on marrow stromal cells cultures (ex vivo, in vitro) comprising osteogenic cells-predecessors, extracted from femurs, studied their peculiarities of the colony formation ablity, the cell structure, some cytological and ultra-structural characteristics and differentiation direction. It was found that that under microgravity conditions there is a decline of the stromal cells colony formation intensity, decrease of the colonies size and cells mitotic activity that indicates decrease of their growth potential. Both in control and in experiment the colonies were presented by population of low-differentiated cells, differentiated cells and mature cells. The comparative cytological and morphometric analysis have shown that the studied stromal cells in colonies have the smaller sizes, more elongated shape, and higher nucleocytoplasmic ratio. Cells composition in the experiment colonies is reliably different by the ratio of the low-differentiating to being differentiated cells; a ratio of low-differentiated to already differentiated cells; ratio of differentiated cells to total number of all cells. In comparison with control group, amount of the cells passed trough a differentiation stage and mature cells in colonies is decreased by 3 to 4 times. Among the differentiated stromal cells in colonies increasing amount of adipocytes was revealed. The analysis of electron microscope microphotographs showed that in osteogenic cells differentiated under microgravity conditions, there is a reduction of the specific volume of a granular endoplasmic reticulum, Golgi's complex and quantity of nuclei reduction that indicates depression of the specific biosyntheses process intensity in cells. The increase of lysosomes and myelinic structures quantity is linked to organelles partial reduction. Consolidation of mitochondrias is an evidence of the cells’ energy

  16. Engineered microtopographies and surface chemistries direct cell attachment and function

    Science.gov (United States)

    Magin, Chelsea Marie

    topographically modified surface (R2=0.82). Functionalized PEGDMA hydrogels significantly reduced attachment and attachment strength of Navicula and C. marina. These hydrogels also reduced attachment of zoospores of Ulva compared to PDMSe. Attachment of Ulva to microtopographies in PDMSe and PEGDMA-co-HEMA negatively correlated with ERIII*Re (R2 = 0.94 and R2 = 0.99, respectively). Incorporating a surface energy term into this equation created a correlation between the attachment densities of cells from two evolutionarily diverse groups on substrates of two surface chemistries with an equation that describes the various microtopographies and surface chemistries in terms of surface energy (R2 = 0.80). The current Attachment Model can now be used to design engineered antifouling surface microtopographies and chemistries that inhibit the attachment of organisms from three evoluntionarily diverse groups. Hydrogels based on PEGDMA were also chosen as a substratum material for mammalian cell culture. Capturing endothelial progenitor cells (EPCs) and inducing differentiation into the endothelial cell (EC) phenotype is the ideal way to re-endothelialize a small-diameter vascular graft. Substratum elasticity has been reported to direct stem cell differentiation into specific lineages. Functionalized PEGDMA hydrogels provided good compliance, high fidelity of topographic features and sites for surface modification with biomolecules. Fibronectin grafting and topography both increased EC attachment. This combination of adjustable elasticity, surface chemistry and topography has the potential to promote the capture and differentiation of EPCs into a confluent EC monolayer. Engineered microtopographies replicated in PDMSe directed elongation and alignment of human coronary artery endothelial cells (HCAECs) and human coronary artery smooth muscle cells (HCASMCs) compared to smooth surfaces. Engineered cellular micro-environments were created with specific surface energies defined by chemistry

  17. RNA Directed Modulation of Phenotypic Plasticity in Human Cells.

    Science.gov (United States)

    Trakman, Laura; Hewson, Chris; Burdach, Jon; Morris, Kevin V

    2016-01-01

    Natural selective processes have been known to drive phenotypic plasticity, which is the emergence of different phenotypes from one genome following environmental stimulation. Long non-coding RNAs (lncRNAs) have been observed to modulate transcriptional and epigenetic states of genes in human cells. We surmised that lncRNAs are governors of phenotypic plasticity and drive natural selective processes through epigenetic modulation of gene expression. Using heat shocked human cells as a model we find several differentially expressed transcripts with the top candidates being lncRNAs derived from retro-elements. One particular retro-element derived transcripts, Retro-EIF2S2, was found to be abundantly over-expressed in heat shocked cells. Over-expression of Retro-EIF2S2 significantly enhanced cell viability and modulated a predisposition for an adherent cellular phenotype upon heat shock. Mechanistically, we find that this retro-element derived transcript interacts directly with a network of proteins including 40S ribosomal protein S30 (FAU), Eukaryotic translation initiation factor 5A (EIF5A), and Ubiquitin-60S ribosomal protein L40 (UBA52) to affect protein modulated cell adhesion pathways. We find one motif in Retro-EIF2S2 that exhibits binding to FAU and modulates phenotypic cell transitions from adherent to suspension states. The observations presented here suggest that retroviral derived transcripts actively modulate phenotypic plasticity in human cells in response to environmental selective pressures and suggest that natural selection may play out through the action of retro-elements in human cells. PMID:27082860

  18. Evidence for bystander signalling between human trophoblast cells and human embryonic stem cells

    OpenAIRE

    Anna J Jones; Gokhale, Paul J; Allison, Thomas F; Barry Sampson; Sharan Athwal; Simon Grant; Andrews, Peter W.; Allen, Nicholas D.; C Patrick Case

    2015-01-01

    Maternal exposure during pregnancy to toxins can occasionally lead to miscarriage and malformation. It is currently thought that toxins pass through the placental barrier, albeit bi-layered in the first trimester, and damage the fetus directly, albeit at low concentration. Here we examined the responses of human embryonic stem (hES) cells in tissue culture to two metals at low concentration. We compared direct exposures with indirect exposures across a bi-layered model of the placenta cell ba...

  19. Coordinated Switching of Bacterial Flagellar Motors: Evidence for Direct Motor-Motor Coupling?

    Science.gov (United States)

    Hu, Bo; Tu, Yuhai

    2013-04-01

    The swimming of Escherichia coli is powered by its multiple flagellar motors. Each motor spins either clockwise or counterclockwise, under the control of an intracellular regulator, CheY-P. There can be two mechanisms (extrinsic and intrinsic) to coordinate the switching of bacterial motors. The extrinsic one arises from the fact that different motors in the same cell sense a common input (CheY-P) which fluctuates near the motors’ response threshold. An alternative, intrinsic mechanism is direct motor-motor coupling which makes synchronized switching energetically favorable. Here, we develop simple models for both mechanisms and uncover their different hallmarks. A quantitative comparison to the recent experiments suggests that the direct coupling mechanism may be accountable for the observed sharp correlation between motors in a single Escherichia coli. Possible origins of this coupling (e.g., hydrodynamic interaction) are discussed.

  20. The directed differentiation of human iPS cells into kidney podocytes.

    Directory of Open Access Journals (Sweden)

    Bi Song

    Full Text Available The loss of glomerular podocytes is a key event in the progression of chronic kidney disease resulting in proteinuria and declining function. Podocytes are slow cycling cells that are considered terminally differentiated. Here we provide the first report of the directed differentiation of induced pluripotent stem (iPS cells to generate kidney cells with podocyte features. The iPS-derived podocytes share a morphological phenotype analogous with cultured human podocytes. Following 10 days of directed differentiation, iPS podocytes had an up-regulated expression of mRNA and protein localization for podocyte markers including synaptopodin, nephrin and Wilm's tumour protein (WT1, combined with a down-regulation of the stem cell marker OCT3/4. In contrast to human podocytes that become quiescent in culture, iPS-derived cells maintain a proliferative capacity suggestive of a more immature phenotype. The transduction of iPS podocytes with fluorescent labeled-talin that were immunostained with podocin showed a cytoplasmic contractile response to angiotensin II (AII. A permeability assay provided functional evidence of albumin uptake in the cytoplasm of iPS podocytes comparable to human podocytes. Moreover, labeled iPS-derived podocytes were found to integrate into reaggregated metanephric kidney explants where they incorporated into developing glomeruli and co-expressed WT1. This study establishes the differentiation of iPS cells to kidney podocytes that will be useful for screening new treatments, understanding podocyte pathogenesis, and offering possibilities for regenerative medicine.

  1. A development of direct hydrazine/hydrogen peroxide fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Lao, Shao Jiang; Qin, Hai Ying; Ye, Li Qiang; Li, Zhou Peng [Department of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027 (China); Liu, Bin Hong [Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China)

    2010-07-01

    A direct hydrazine fuel cell using H{sub 2}O{sub 2} as the oxidizer has been developed. The N{sub 2}H{sub 4}/H{sub 2}O{sub 2} fuel cell is assembled by using Ni-Pt/C composite catalyst as the anode catalyst, Au/C as the cathode catalyst, and Nafion membrane as the electrolyte. Both anolyte and catholyte show significant influences on cell voltage and cell performance. The open-circuit voltage of the N{sub 2}H{sub 4}/H{sub 2}O{sub 2} fuel cell reaches up to 1.75 V when using alkaline N{sub 2}H{sub 4} solution as the anolyte and acidic H{sub 2}O{sub 2} solution as the catholyte. A maximum power density of 1.02 W cm{sup -2} has been achieved at operation temperature of 80 C. The number of electrons exchanged in the H{sub 2}O{sub 2} reduction reaction on Au/C catalyst is 2. (author)

  2. Efficient direct ZnO/CIS solar cells

    Science.gov (United States)

    Olsen, Larry C.; William Addis, F.; Lei, Wenhua; Li, Jun

    1996-01-01

    This paper describes investigations of CIS solar cells with ZnO window layers deposited by MOCVD. These studies have been conducted with graded absorber CIS substrates obtained from Siemens Solar. Cell fabrication involves surface preparation of the Siemens substrate, growth of 200 to 400 Å of undoped ZnO by MOCVD, deposition of a highly conducting ZnO top contact layer and deposition of a Ni/Ag collector grid. MOCVD growth of ZnO is accomplished in a SPIRE 500XT reactor by reacting a zinc adduct and tetrahydrofuran. Processing development has been conducted by forming test cells on ZnO/CIS structures by depositing thin, transparent Al contacts 2.8 mm in diameter on top of the ZnO window layer to serve as contacts. Several cells have been completed with a total area efficiency ≥11.0%, with the best result being 11.3%. The best active area efficiency is approximately 12%. Other topics discussed include current-voltage characteristics of direct ZnO/CIS cells.

  3. Minimal second language exposure, SES, and early word comprehension: New evidence from a direct assessment*

    Science.gov (United States)

    Deanda, Stephanie; Arias-Trejo, Natalia; Poulin-Dubois, Diane; Zesiger, Pascal; Friend, Margaret

    2015-01-01

    Although the extant literature provides robust evidence of the influence of language exposure and socioeconomic status (SES) on language acquisition, it is unknown how sensitive the early receptive vocabulary system is to these factors. The current study investigates effects of minimal second language exposure and SES on the comprehension vocabulary of 16-month-old children in the language in which they receive the greatest exposure. Study 1 revealed minimal second language exposure and SES exert significant and independent effects on a direct measure of vocabulary comprehension in English-dominant and English monolingual children (N = 72). In Study 2, we replicated the effect of minimal second language exposure in Spanish-dominant and Spanish monolingual children (N = 86), however no effect of SES on vocabulary was obtained. Our results emphasize the sensitivity of the language system to minimal changes in the environment in early development. PMID:26957947

  4. Learning through EC directive based SEA in spatial planning? Evidence from the Brunswick Region in Germany

    International Nuclear Information System (INIS)

    This paper presents results of an international comparative research project, funded by the UK Economic and Social Research Council (ESRC) and the Academy for Sustainable Communities (ASC) on the 'learning potential of appraisal (strategic environmental assessment - SEA) in spatial planning'. In this context, aspects of 'single-loop' and 'double-loop' learning, as well as of individual, organisational and social learning are discussed for emerging post-EC Directive German practice in the planning region (Zweckverband) of Brunswick (Braunschweig), focusing on four spatial plan SEAs from various administrative levels in the region. It is found that whilst SEA is able to lead to plan SEA specific knowledge acquisition, comprehension, application and analysis ('single-loop learning'), it is currently resulting only occasionally in wider synthesis and evaluation ('double-loop learning'). Furthermore, whilst there is evidence that individual and occasionally organisational learning may be enhanced through SEA, most notably in small municipalities, social learning appears to be happening only sporadically.

  5. First direct evidence of a vertebrate three-level trophic chain in the fossil record.

    Science.gov (United States)

    Kriwet, Jürgen; Witzmann, Florian; Klug, Stefanie; Heidtke, Ulrich H J

    2008-01-22

    We describe the first known occurrence of a Permian shark specimen preserving two temnospondyl amphibians in its digestive tract as well as the remains of an acanthodian fish, which was ingested by one of the temnospondyls. This exceptional find provides for the first time direct evidence of a vertebrate three-level food chain in the fossil record with the simultaneous preservation of three trophic levels. Our analysis shows that small-sized Lower Permian xenacanthid sharks of the genus Triodus preyed on larval piscivorous amphibians. The recorded trophic interaction can be explained by the adaptation of certain xenacanthids to fully freshwater environments and the fact that in these same environments, large temnospondyls occupied the niche of modern crocodiles. This unique faunal association has not been documented after the Permian and Triassic. Therefore, this Palaeozoic three-level food chain provides strong and independent support for changes in aquatic trophic chain structures through time. PMID:17971323

  6. Direct Evidence of Cold Gas in DLA 0812+32B

    CERN Document Server

    Jorgenson, Regina A; Prochaska, J Xavier; Carswell, Robert F

    2009-01-01

    We present the first direct evidence for cold gas in a high redshift DLA galaxy. We measured several multiplets of weak neutral carbon (CI) transitions in order to perform a curve of growth analysis. A delta chi-squared test constrains the best fit Doppler parameter, b = 0.33_{-0.04}^{+0.05} km/s, and logN(CI) = 13.30 +- 0.2 cm^-2. This Doppler parameter constrains the kinetic temperature of the gas to T = 0.06) with an excitation temperature of T_{ex} = 46 K as determined by the rotational J = 0 and J = 1 states, is consistent with the presence of cold gas. We propose that this cloud may be gravitationally confined and may represent a transition gas-phase from primarily neutral atomic gas, to a colder, denser molecular phase that will eventually host star formation.

  7. Direct and Indirect Evidence of Size-Selective Grazing on Pelagic Bacteria by Freshwater Nanoflagellates

    Science.gov (United States)

    Šimek, Karel; Chrzanowski, Thomas H.

    1992-01-01

    Size-selective grazing of three heterotrophic nanoflagellates (with cell sizes of 21, 44, and 66 μm3) isolated from Lake Arlington, Texas was examined by using a natural mixture of fluorescence labelled lake bacteria. Sizes of ingested bacteria in food vacuoles were directly measured. Larger bacterial cells were ingested at a frequency much higher than that at which they occurred in the assemblage, indicating preferential flagellate grazing on the larger size classes within the lake bacterioplankton. Water samples were collected biweekly from June through September, 1989, fractionated by filtration, and incubated for 40 h at in situ temperatures. The average bacterial size was always larger in water which was passed through 1-μm-pore-size filters (1-μm-filtered water) (which was predator free) than in 5-μm-filtered water (which contained flagellates only) or in unfiltered water (in which all bacterivores were present). The increase of bacterial-cell size in 1-μm-filtered water was caused by a shift in the size structure of the bacterioplankton population. Larger cells became more abundant in the absence of flagellate grazing. PMID:16348811

  8. Direct Methanol Fuel Cell Prototype Demonstration for Consumer Electronics Applications

    Energy Technology Data Exchange (ETDEWEB)

    Carlstrom, Charles, M., Jr.

    2009-07-07

    This report is the final technical report for DOE Program DE-FC36-04GO14301 titled “Direct Methanol Fuel Cell Prototype Demonstration for Consumer Electronics Applications”. Due to the public nature of this report some of the content reported in confidential reports and meetings to the DOE is not covered in detail in this report and some of the content has been normalized to not show actual values. There is a comparison of the projects accomplishments with the objectives, an overview of some of the key subsystem work, and a review of the three levels of prototypes demonstrated during the program. There is also a description of the eventual commercial product and market this work is leading towards. The work completed under this program has significantly increased the understanding of how Direct Methanol Fuel Cells (DMFC) can be deployed successfully to power consumer electronic devices. The prototype testing has demonstrated the benefits a direct methanol fuel cell system has over batteries typically used for powering consumer electronic devices. Three generations of prototypes have been developed and tested for performance, robustness and life. The technologies researched and utilized in the fuel cell stack and related subsystems for these prototypes are leveraged from advances in other industries such as the hydrogen fueled PEM fuel cell industry. The work under this program advanced the state of the art of direct methanol fuel cells. The system developed by MTI micro fuel cells aided by this program differs significantly from conventional DMFC designs and offers compelling advantages in the areas of performance, life, size, and simplicity. The program has progressed as planned resulting in the completion of the scope of work and available funding in December 2008. All 18 of the final P3 prototypes builds have been tested and the results showed significant improvements over P2 prototypes in build yield, initial performance, and durability. The systems have

  9. The direction of word stress processing in German: Evidence from a working memory paradigm

    Directory of Open Access Journals (Sweden)

    Frank eDomahs

    2014-06-01

    Full Text Available There are contradicting assumptions and findings on the direction of word stress processing in German. To resolve this question, we asked participants to read tri-syllabic nonwords and stress ambiguous words aloud. Additionally, they also performed a working memory task (2-back task. In nonword reading, participants’ individual working memory capacity was positively correlated with assignment of main stress to the antepenultimate syllable, which is most distant to the word’s right edge, while a (complementary negative correlation was observed with assignment of stress to the ultimate syllable. There was no significant correlation between working memory capacity and stress assignment to the penultimate syllable, which has been claimed to be the default stress pattern in German. In reading stress ambiguous words a similar but non-significant pattern was observed as in nonword reading. In sum, our results provide first psycholinguistic evidence supporting leftward stress processing in German. Our results do not lend support to the assumption of penultimate default stress in German. A specification of the lemma model is proposed which seems able to reconcile our findings and apparently contradicting assumptions and evidence.

  10. The direction of word stress processing in German: evidence from a working memory paradigm.

    Science.gov (United States)

    Domahs, Frank; Grande, Marion; Huber, Walter; Domahs, Ulrike

    2014-01-01

    There are contradicting assumptions and findings on the direction of word stress processing in German. To resolve this question, we asked participants to read tri-syllabic non-words and stress ambiguous words aloud. Additionally, they also performed a working memory (WM) task (2-back task). In non-word reading, participants' individual WM capacity was positively correlated with assignment of main stress to the antepenultimate syllable, which is most distant to the word's right edge, while a (complementary) negative correlation was observed with assignment of stress to the ultimate syllable. There was no significant correlation between WM capacity and stress assignment to the penultimate syllable, which has been claimed to be the default stress pattern in German. In reading stress ambiguous words, a similar but non-significant pattern was observed as in non-word reading. In sum, our results provide first psycholinguistic evidence supporting leftward stress processing in German. Our results do not lend support to the assumption of penultimate default stress in German. A specification of the lemma model is proposed which seems able to reconcile our findings and apparently contradicting assumptions and evidence. PMID:24966845

  11. Direct measurement of helical cell motion of the spirochete leptospira.

    Science.gov (United States)

    Nakamura, Shuichi; Leshansky, Alexander; Magariyama, Yukio; Namba, Keiichi; Kudo, Seishi

    2014-01-01

    Leptospira are spirochete bacteria distinguished by a short-pitch coiled body and intracellular flagella. Leptospira cells swim in liquid with an asymmetric morphology of the cell body; the anterior end has a long-pitch spiral shape (S-end) and the posterior end is hook-shaped (H-end). Although the S-end and the coiled cell body called the protoplasmic cylinder are thought to be responsible for propulsion together, most observations on the motion mechanism have remained qualitative. In this study, we analyzed the swimming speed and rotation rate of the S-end, protoplasmic cylinder, and H-end of individual Leptospira cells by one-sided dark-field microscopy. At various viscosities of media containing different concentrations of Ficoll, the rotation rate of the S-end and protoplasmic cylinder showed a clear correlation with the swimming speed, suggesting that these two helical parts play a central role in the motion of Leptospira. In contrast, the H-end rotation rate was unstable and showed much less correlation with the swimming speed. Forces produced by the rotation of the S-end and protoplasmic cylinder showed that these two helical parts contribute to propulsion at nearly equal magnitude. Torque generated by each part, also obtained from experimental motion parameters, indicated that the flagellar motor can generate torque >4000 pN nm, twice as large as that of Escherichia coli. Furthermore, the S-end torque was found to show a markedly larger fluctuation than the protoplasmic cylinder torque, suggesting that the unstable H-end rotation might be mechanically related to changes in the S-end rotation rate for torque balance of the entire cell. Variations in torque at the anterior and posterior ends of the Leptospira cell body could be transmitted from one end to the other through the cell body to coordinate the morphological transformations of the two ends for a rapid change in the swimming direction. PMID:24411236

  12. Spatially patterned matrix elasticity directs stem cell fate

    Science.gov (United States)

    Yang, Chun; DelRio, Frank W.; Ma, Hao; Killaars, Anouk R.; Basta, Lena P.; Kyburz, Kyle A.; Anseth, Kristi S.

    2016-01-01

    There is a growing appreciation for the functional role of matrix mechanics in regulating stem cell self-renewal and differentiation processes. However, it is largely unknown how subcellular, spatial mechanical variations in the local extracellular environment mediate intracellular signal transduction and direct cell fate. Here, the effect of spatial distribution, magnitude, and organization of subcellular matrix mechanical properties on human mesenchymal stem cell (hMSCs) function was investigated. Exploiting a photodegradation reaction, a hydrogel cell culture substrate was fabricated with regions of spatially varied and distinct mechanical properties, which were subsequently mapped and quantified by atomic force microscopy (AFM). The variations in the underlying matrix mechanics were found to regulate cellular adhesion and transcriptional events. Highly spread, elongated morphologies and higher Yes-associated protein (YAP) activation were observed in hMSCs seeded on hydrogels with higher concentrations of stiff regions in a dose-dependent manner. However, when the spatial organization of the mechanically stiff regions was altered from a regular to randomized pattern, lower levels of YAP activation with smaller and more rounded cell morphologies were induced in hMSCs. We infer from these results that irregular, disorganized variations in matrix mechanics, compared with regular patterns, appear to disrupt actin organization, and lead to different cell fates; this was verified by observations of lower alkaline phosphatase (ALP) activity and higher expression of CD105, a stem cell marker, in hMSCs in random versus regular patterns of mechanical properties. Collectively, this material platform has allowed innovative experiments to elucidate a novel spatial mechanical dosing mechanism that correlates to both the magnitude and organization of spatial stiffness. PMID:27436901

  13. Chaos evidence in catecholamine secretion at chromaffin cells

    International Nuclear Information System (INIS)

    Highlights: ► Nonlinear behavior in protein secretion. ► Nonlinear characterization of complex behavior in catecholamine secretion. ► Chaos in chromaffin cells activity at the adrenaline secretion. ► Preliminary evidences on the chaotic behavior in catecholamine secretion. - Abstract: Chromaffin cells secrete catecholamine molecules via exocytosis process. Each exocytotic event is characterized by a current spike, which corresponds to the amount of released catecholamine from secretory vesicles after fusing to plasma membrane. The current spike might be measured by the oxidation of catecholamine molecules and can be experimentally detected through amperometry technique. In this contribution, the secretion of catecholamine, namely adrenaline, of a set of bovine chromaffin cells is measured individually at each single cell. The aim is to study quantitative results of chaotic behavior in catecholamine secretion. For analysis, time series were obtained from amperometric measurements of each single chromaffin cell. Three analysis techniques were exploited: (i) A low-order attractor was generated by means of phase space reconstruction, Average Mutual Information (AMI) and False Nearest Neighbors (FNN) were used to compute embedding lag and embedding dimension, respectively. (ii) The properties of power spectrum density of time series were studied by Fast Fourier Transform (FFT) looking for possible dominant frequencies in power spectrum. (iii) Maximun Lyapunov Exponent (MLE) analysis was done to study the divergence of trajectories of the time series. Nevertheless, in order to dismiss the possibility of positiveness of MLE are due to the inherent noise in experiments, seven surrogate data sets computed using the Amplitude Adjusted Fourier Transform (AAFT) algorithm was computed. The phase space reconstruction showed that, in all cases, the trajectories lie in an embedding subspace suggesting oscillatory nature. The FFT analysis showed high dispersion of the power

  14. Direct evidence of strong local ferroelectric ordering in a thermoelectric semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Aggarwal, Leena; Sekhon, Jagmeet S.; Arora, Ashima; Sheet, Goutam, E-mail: goutam@iisermohali.ac.in [Department of Physical Sciences, Indian Institute of Science Education and Research Mohali (IISER M), Sector 81, S. A. S. Nagar, Manauli PO-140306 (India); Guin, Satya N.; Negi, Devendra S.; Datta, Ranjan; Biswas, Kanishka, E-mail: kanishka@jncasr.ac.in [New Chemistry Unit and International Centre for Materials Science, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bangalore 560064 (India)

    2014-09-15

    It is thought that the proposed new family of multi-functional materials, namely, the ferroelectric thermoelectrics may exhibit enhanced functionalities due to the coupling of the thermoelectric parameters with ferroelectric polarization in solids. Therefore, the ferroelectric thermoelectrics are expected to be of immense technological and fundamental significance. As a first step towards this direction, it is most important to identify the existing high performance thermoelectric materials exhibiting ferroelectricity. Herein, through the direct measurement of local polarization switching, we show that the recently discovered thermoelectric semiconductor AgSbSe{sub 2} has local ferroelectric ordering. Using piezo-response force microscopy, we demonstrate the existence of nanometer scale ferroelectric domains that can be switched by external electric field. These observations are intriguing as AgSbSe{sub 2} crystalizes in cubic rock-salt structure with centro-symmetric space group (Fm–3m), and therefore, no ferroelectricity is expected. However, from high resolution transmission electron microscopy measurement, we found the evidence of local superstructure formation which, we believe, leads to local distortion of the centro-symmetric arrangement in AgSbSe{sub 2} and gives rise to the observed ferroelectricity. Stereochemically active 5S{sup 2} lone-pair of Sb may also give rise to local structural distortion thereby creating ferroelectricity in AgSbSe{sub 2}.

  15. Direct evidence of strong local ferroelectric ordering in a thermoelectric semiconductor

    International Nuclear Information System (INIS)

    It is thought that the proposed new family of multi-functional materials, namely, the ferroelectric thermoelectrics may exhibit enhanced functionalities due to the coupling of the thermoelectric parameters with ferroelectric polarization in solids. Therefore, the ferroelectric thermoelectrics are expected to be of immense technological and fundamental significance. As a first step towards this direction, it is most important to identify the existing high performance thermoelectric materials exhibiting ferroelectricity. Herein, through the direct measurement of local polarization switching, we show that the recently discovered thermoelectric semiconductor AgSbSe2 has local ferroelectric ordering. Using piezo-response force microscopy, we demonstrate the existence of nanometer scale ferroelectric domains that can be switched by external electric field. These observations are intriguing as AgSbSe2 crystalizes in cubic rock-salt structure with centro-symmetric space group (Fm–3m), and therefore, no ferroelectricity is expected. However, from high resolution transmission electron microscopy measurement, we found the evidence of local superstructure formation which, we believe, leads to local distortion of the centro-symmetric arrangement in AgSbSe2 and gives rise to the observed ferroelectricity. Stereochemically active 5S2 lone-pair of Sb may also give rise to local structural distortion thereby creating ferroelectricity in AgSbSe2.

  16. Direct evidence for impact winter following the Cretaceous-Paleogene bolide impact

    Science.gov (United States)

    Vellekoop, J.; Sluijs, A.; Smit, J.; Schouten, S.; Sinninghe Damsté, J. S.; Brinkhuis, H.

    2012-12-01

    The Cretaceous/Paleogene (K/Pg) boundary, ~65.5 Ma, marks a mass-extinction event related the impact of a large asteroid on the Yucatan peninsula, Mexico. Model scenarios predict that the explosive injection of dust and sulfate aerosols into the stratosphere blocked incoming solar radiation, resulting in a cooling pulse of months to several decades, a so-called 'impact winter', but thus far, proxy records lack sufficient resolution to evaluate this hypothesis. We report on a major, short-lived drop in sea surface temperatures (SSTs) recorded in an unusually well preserved and stratigraphically expanded K/Pg boundary site in Texas, USA, based on TEX86 paleothermometry. Critically, the cooling directly post-dates impact-related tsunami deposits, and coincides with the deposition of extraterrestrial iridium representing aerosol fall out, restricting the age of the cooling to the first months to decades after impact. We interpret this cooling to reflect the first direct evidence for the "impact winter" at the K/Pg boundary. The combination of darkness and cooling must have been a key contributory element in the extinctions of many biological clades, including the dinosaurs, flying reptiles and marine reptiles.

  17. Evidence of a Direct Evolutionary Selection for Strong Folding and Mutational Robustness Within HIV Coding Regions.

    Science.gov (United States)

    Goz, Eli; Tuller, Tamir

    2016-08-01

    A large number of studies demonstrated the importance of different HIV RNA structural elements at all stages of the viral life cycle. Nevertheless, the significance of many of these structures is unknown, and plausibly new regions containing RNA structure-mediated regulatory signals remain to be identified. An important characteristic of genomic regions carrying functionally significant secondary structures is their mutational robustness, that is, the extent to which a sequence remains constant in spite of despite mutations in terms of its underlying secondary structure. Structural robustness to mutations is expected to be important in the case of functional RNA structures in viruses with high mutation rate; it may prevent fitness loss due to disruption of possibly functional conformations, pointing to the specific significance of the corresponding genomic region. In the current work, we perform a genome-wide computational analysis to detect signals of a direct evolutionary selection for strong folding and RNA structure-based mutational robustness within HIV coding sequences. We provide evidence that specific regions of HIV structural genes undergo an evolutionary selection for strong folding; in addition, we demonstrate that HIV Rev responsive element seems to undergo a direct evolutionary selection for increased secondary structure robustness to point mutations. We believe that our analysis may enable a better understanding of viral evolutionary dynamics at the RNA structural level and may benefit to practical efforts of engineering antiviral vaccines and novel therapeutic approaches. PMID:27347769

  18. Evidence for direct geographic influences on linguistic sounds: the case of ejectives.

    Directory of Open Access Journals (Sweden)

    Caleb Everett

    Full Text Available We present evidence that the geographic context in which a language is spoken may directly impact its phonological form. We examined the geographic coordinates and elevations of 567 language locations represented in a worldwide phonetic database. Languages with phonemic ejective consonants were found to occur closer to inhabitable regions of high elevation, when contrasted to languages without this class of sounds. In addition, the mean and median elevations of the locations of languages with ejectives were found to be comparatively high. The patterns uncovered surface on all major world landmasses, and are not the result of the influence of particular language families. They reflect a significant and positive worldwide correlation between elevation and the likelihood that a language employs ejective phonemes. In addition to documenting this correlation in detail, we offer two plausible motivations for its existence. We suggest that ejective sounds might be facilitated at higher elevations due to the associated decrease in ambient air pressure, which reduces the physiological effort required for the compression of air in the pharyngeal cavity--a unique articulatory component of ejective sounds. In addition, we hypothesize that ejective sounds may help to mitigate rates of water vapor loss through exhaled air. These explications demonstrate how a reduction of ambient air density could promote the usage of ejective phonemes in a given language. Our results reveal the direct influence of a geographic factor on the basic sound inventories of human languages.

  19. Direct Evidence of the Transition from Weak to Strong MHD Turbulence

    CERN Document Server

    Meyrand, Romain; Kiyani, Khurom H

    2015-01-01

    One of the most important predictions in magnetohydrodynamics (MHD) is that in the presence of a uniform magnetic field $\\textbf{b}_{0}$ a transition from weak to strong wave turbulence should occur when going from large to small perpendicular scales. This transition is believed to be a universal property of several anisotropic turbulent systems. We present for the first time direct evidence of such a transition thanks to a three-dimensional direct numerical simulation of incompressible balanced MHD turbulence with a grid resolution of $3072^2 \\times 256$. From large to small-scales, the change of regime is characterized by i) a change of slope in the energy spectrum going from approximately $-2$ to $-3/2$; ii) an increase of the ratio between the wave and nonlinear times, with a critical ratio of $\\chi_{c}\\sim0.35$; iii) an absence followed by a dramatic increase of the communication between Alfv\\'en modes; and iv) a modification of the iso-contours of energy revealing a transition from a purely perpendicula...

  20. Alarm system management: evidence-based guidance encouraging direct measurement of informativeness to improve alarm response.

    Science.gov (United States)

    Rayo, Michael F; Moffatt-Bruce, Susan D

    2015-04-01

    Although there are powerful incentives for creating alarm management programmes to reduce 'alarm fatigue', they do not provide guidance on how to reduce the likelihood that clinicians will disregard critical alarms. The literature cites numerous phenomena that contribute to alarm fatigue, although many of these, including total rate of alarms, are not supported in the literature as factors that directly impact alarm response. The contributor that is most frequently associated with alarm response is informativeness, which is defined as the proportion of total alarms that successfully conveys a specific event, and the extent to which it is a hazard. Informativeness is low across all healthcare applications, consistently ranging from 1% to 20%. Because of its likelihood and strong evidential support, informativeness should be evaluated before other contributors are considered. Methods for measuring informativeness and alarm response are discussed. Design directions for potential interventions, as well as design alternatives to traditional alarms, are also discussed. With the increased attention and investment in alarm system management that alarm interventions are currently receiving, initiatives that focus on informativeness and the other evidence-based measures identified will allow us to more effectively, efficiently and reliably redirect clinician attention, ultimately improving alarm response. PMID:25734193

  1. No evidence for directional evolution of body mass in herbivorous theropod dinosaurs.

    Science.gov (United States)

    Zanno, Lindsay E; Makovicky, Peter J

    2013-01-22

    The correlation between large body size and digestive efficiency has been hypothesized to have driven trends of increasing mass in herbivorous clades by means of directional selection. Yet, to date, few studies have investigated this relationship from a phylogenetic perspective, and none, to our knowledge, with regard to trophic shifts. Here, we reconstruct body mass in the three major subclades of non-avian theropod dinosaurs whose ecomorphology is correlated with extrinsic evidence of at least facultative herbivory in the fossil record--all of which also achieve relative gigantism (more than 3000 kg). Ordinary least-squares regressions on natural log-transformed mean mass recover significant correlations between increasing mass and geological time. However, tests for directional evolution in body mass find no support for a phylogenetic trend, instead favouring passive models of trait evolution. Cross-correlation of sympatric taxa from five localities in Asia reveals that environmental influences such as differential habitat sampling and/or taphonomic filtering affect the preserved record of dinosaurian body mass in the Cretaceous. Our results are congruent with studies documenting that behavioural and/or ecological factors may mitigate the benefit of increasing mass in extant taxa, and suggest that the hypothesis can be extrapolated to herbivorous lineages across geological time scales. PMID:23193135

  2. Direct evidences for inner-shell electron-excitation by laser induced electron recollision

    CERN Document Server

    Deng, Yunpei; Jia, Zhengmao; Komm, Pavel; Zheng, Yinhui; Ge, Xiaochun; Li, Ruxin; Marcus, Gilad

    2015-01-01

    Extreme ultraviolet (XUV) attosecond pulses, generated by a process known as laser-induced electron recollision, are a key ingredient for attosecond metrology, providing a tool to precisely initiate and probe sub-femtosecond dynamics in the microcosms of atoms, molecules and solids[1]. However, with the current technology, extending attosecond metrology to scrutinize the dynamics of the inner-shell electrons is a challenge, that is because of the lower efficiency in generating the required soft x-ray \\hbar\\omega>300 eV attosecond bursts and the lower absorption cross-sections in this spectral range. A way around this problem is to use the recolliding electron to directly initiate the desired inner-shell process, instead of using the currently low flux x-ray attosecond sources.Such an excitation process occurs in a sub-femtosecond timescale, and may provide the necessary "pump" step in a pump-probe experiment[2]. Here we used a few cycle infrared \\lambda_{0}~1800nm source[3] and observed direct evidences for i...

  3. Direct Evidence of the Transition from Weak to Strong Magnetohydrodynamic Turbulence.

    Science.gov (United States)

    Meyrand, Romain; Galtier, Sébastien; Kiyani, Khurom H

    2016-03-11

    One of the most important predictions in magnetohydrodynamics is that in the presence of a uniform magnetic field b_{0}e[over ^]_{∥} a transition from weak to strong wave turbulence should occur when going from large to small perpendicular scales. This transition is believed to be a universal property of several anisotropic turbulent systems. We present, for the first time, direct evidence of such a transition using a decaying three-dimensional direct numerical simulation of incompressible balanced magnetohydrodynamic turbulence with a grid resolution of 3072^{2}×256. From large to small scales, the change of regime is characterized by (i) a change of slope in the energy spectrum going from approximately -2 to -3/2, (ii) an increase of the ratio between the wave and nonlinear times, with a critical ratio of χ_{c}∼1/3, (iii) a modification of the isocontours of energy revealing a transition from a purely perpendicular cascade to a cascade compatible with the critical-balance-type phenomenology, and (iv) an absence followed by a dramatic increase of the communication between Alfvén modes. The changes happen at approximately the same transition scale and can be seen as manifest signatures of the transition from weak to strong wave turbulence. Furthermore, we observe a significant nonlocal three-wave coupling between strongly and weakly nonlinear modes resulting in an inverse transfer of energy from small to large scales. PMID:27015486

  4. Direct Evidence of EMIC-Driven Electron Loss in Space: Evaluation of an Electron Dropout Event

    Science.gov (United States)

    Zhang, X.; Li, W.; Ma, Q.; Thorne, R. M.; Angelopoulos, V.

    2015-12-01

    Electromagnetic ion cyclotron (EMIC) waves have been proposed as a mechanism to cause efficient losses of highly relativistic (>MeV) electrons via gyroresonant interactions. However, simultaneous observations of EMIC waves and equatorial electron pitch angle distributions, which can be used to directly quantify the EMIC wave scattering effect, are still very limited. In the present study, we evaluate the effect of EMIC waves on the pitch angle scattering of relativistic and ultrarelativistic (0.5-5 MeV) electrons during the main phase of a geomagnetic storm, when intense EMIC wave activity was observed in situ (in the plasma plume region with high plasma density) on both the Van Allen Probes and one of the THEMIS probes. EMIC waves captured on the ground across the Canadian Array for Real-time Investigations of Magnetic Activity (CARISMA) and enhanced precipitation of >~0.7 MeV electrons captured by POES are used to infer the MLT coverage of EMIC waves. Based on the observed EMIC wave spectra, local fpe and fce, we estimate the wave diffusion rates and model the evolution of electron pitch angle distributions. By comparing the modeled results with local observations of pitch angle distributions, for the first time, we are able to show direct, quantitative evidence of EMIC wave-driven relativistic electron loss in the Earth's outer radiation belt.

  5. Direct Evidence of the Transition from Weak to Strong Magnetohydrodynamic Turbulence

    Science.gov (United States)

    Meyrand, Romain; Galtier, Sébastien; Kiyani, Khurom H.

    2016-03-01

    One of the most important predictions in magnetohydrodynamics is that in the presence of a uniform magnetic field b0e^∥ a transition from weak to strong wave turbulence should occur when going from large to small perpendicular scales. This transition is believed to be a universal property of several anisotropic turbulent systems. We present, for the first time, direct evidence of such a transition using a decaying three-dimensional direct numerical simulation of incompressible balanced magnetohydrodynamic turbulence with a grid resolution of 30722×256 . From large to small scales, the change of regime is characterized by (i) a change of slope in the energy spectrum going from approximately -2 to -3 /2 , (ii) an increase of the ratio between the wave and nonlinear times, with a critical ratio of χc˜1 /3 , (iii) a modification of the isocontours of energy revealing a transition from a purely perpendicular cascade to a cascade compatible with the critical-balance-type phenomenology, and (iv) an absence followed by a dramatic increase of the communication between Alfvén modes. The changes happen at approximately the same transition scale and can be seen as manifest signatures of the transition from weak to strong wave turbulence. Furthermore, we observe a significant nonlocal three-wave coupling between strongly and weakly nonlinear modes resulting in an inverse transfer of energy from small to large scales.

  6. Direct Evidence for Bottom-fishing in Archaeological Whelks (Buccinum undatum

    Directory of Open Access Journals (Sweden)

    Greg Campbell

    2014-09-01

    Full Text Available Bottom-fishing is a major step in the increase of exploitation of marine resources, requiring specialised craft, technology, and practitioners. However, the onset and development of bottom-fishing is almost impossible to observe directly in the archaeological record, and is usually reconstructed by implication. The shells of common whelk (Buccinum undatum from a kitchen midden at Carisbrooke Castle, Isle of Wight, southern England, showed a pattern of damage characteristic of harvesting by bottom-fishing, rather than the usual baited pots. Some whelks had survived being dredged several times. The very consistent size-shape relationship made it likely the whelks were all from a single habitat, probably in the fast tidal flows typical of the oyster-beds just north of the island. The whelks were harvested along with oysters: the whelks' shells were encrusted in a similar way to the oysters in the same midden, and the whelks even bore sub-adult oysters (spat, despite these being potential prey for whelks. This may be the first time whelks have been shown to have been harvested along with oysters and also seems the first direct evidence for a bottom-fishery for whelks.

  7. Novel Materials for High Efficiency Direct Methanol Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Carson, Stephen; Mountz, David; He, Wensheng; Zhang, Tao

    2013-12-31

    Direct methanol fuel cell membranes were developed using blends of different polyelectrolytes with PVDF. The membranes showed complex relationships between polyelectrolyte chemistry, morphology, and processing. Although the PVDF grade was found to have little effect on the membrane permselectivity, it does impact membrane conductivity and methanol permeation values. Other factors, such as varying the polyelectrolyte polarity, using varying crosslinking agents, and adjusting the equivalent weight of the membranes impacted methanol permeation, permselectivity, and areal resistance. We now understand, within the scope of the project work completed, how these inter-related performance properties can be tailored to achieve a balance of performance.

  8. Maximum power point tracking control of direct methanol fuel cells

    Science.gov (United States)

    Zhang, Mingbo; Yan, Ting; Gu, Jinguang

    2014-02-01

    The performance of a direct methanol fuel cell (DMFC) is closely related to its operating conditions, and there is a specific combination of operating conditions at which the DMFC produces maximum power. Working at the maximum power point (MPP) can lower the methanol crossover rate and ancillary power consumption, improving the global efficiency of the system. The fuzzy controller proposed in this paper provides a simple and robust way to keep the DMFC working at the MPP by adjusting the operating conditions followed by the variation of the driven load in real time. Simulation shows that the fuzzy control approach can yield satisfactory results.

  9. Progress toward cell-directed therapy for phenylketonuria.

    Science.gov (United States)

    Harding, Co

    2008-08-01

    Phenylketonuria (PKU) is one of the most common inborn errors of metabolism with an annual incidence of approximately 1:16,000 live births in North America. Contemporary therapy relies upon lifelong dietary protein restriction and supplementation with phenylalanine-free medical foods. This therapy is expensive and unpalatable; dietary compliance is difficult to maintain throughout life. Non-adherence to the diet is associated with learning disabilities, adult-onset neurodegenerative disease, and maternal PKU syndrome. The fervent dream of many individuals with PKU is a more permanent cure for this disease. This paper will review ongoing efforts to develop viable cell-directed therapies, in particular cell transplantation and gene therapy, for the treatment of PKU. PMID:18498375

  10. Micro-crack formation in direct methanol fuel cell electrodes

    Science.gov (United States)

    Li, Qing; Spernjak, Dusan; Zelenay, Piotr; Kim, Yu Seung

    2014-12-01

    This study focuses on the micro-crack formation of Nafion®-based membrane electrode assemblies (MEAs) after extended direct methanol fuel cell (DMFC) operation. All electrodes, both with metal-black and carbon-supported catalysts, contain some micro-cracks initially; the area covered by these cracks increases both in the anode and cathode after 100-hours of DMFC test. X-ray tomography shows an increase in the crack area in both anode and cathode that correlates with methanol feed concentration and methanol crossover. The MEAs with carbon-supported catalysts and thicker membrane are more resistant to the formation of micro-cracks compared to those with metal-black catalysts and thinner membrane, respectively. The impact of the micro-crack formation on cell performance and durability is limited over the 100-hour DMFC operation, with the long-term impact remaining unknown.

  11. Direct determination of phosphatase activity from physiological substrates in cells.

    Directory of Open Access Journals (Sweden)

    Zhongyuan Ren

    Full Text Available A direct and continuous approach to determine simultaneously protein and phosphate concentrations in cells and kinetics of phosphate release from physiological substrates by cells without any labeling has been developed. Among the enzymes having a phosphatase activity, tissue non-specific alkaline phosphatase (TNAP performs indispensable, multiple functions in humans. It is expressed in numerous tissues with high levels detected in bones, liver and neurons. It is absolutely required for bone mineralization and also necessary for neurotransmitter synthesis. We provided the proof of concept that infrared spectroscopy is a reliable assay to determine a phosphatase activity in the osteoblasts. For the first time, an overall specific phosphatase activity in cells was determined in a single step by measuring simultaneously protein and substrate concentrations. We found specific activities in osteoblast like cells amounting to 116 ± 13 nmol min(-1 mg(-1 for PPi, to 56 ± 11 nmol min(-1 mg(-1 for AMP, to 79 ± 23 nmol min(-1 mg(-1 for beta-glycerophosphate and to 73 ± 15 nmol min(-1 mg(-1 for 1-alpha-D glucose phosphate. The assay was also effective to monitor phosphatase activity in primary osteoblasts and in matrix vesicles. The use of levamisole--a TNAP inhibitor--served to demonstrate that a part of the phosphatase activity originated from this enzyme. An IC50 value of 1.16 ± 0.03 mM was obtained for the inhibition of phosphatase activity of levamisole in osteoblast like cells. The infrared assay could be extended to determine any type of phosphatase activity in other cells. It may serve as a metabolomic tool to monitor an overall phosphatase activity including acid phosphatases or other related enzymes.

  12. Tuning cell adhesion by direct nanostructuring silicon into cell repulsive/adhesive patterns

    International Nuclear Information System (INIS)

    Developing platforms that allow tuning cell functionality through incorporating physical, chemical, or mechanical cues onto the material surfaces is one of the key challenges in research in the field of biomaterials. In this respect, various approaches have been proposed and numerous structures have been developed on a variety of materials. Most of these approaches, however, demand a multistep process or post-chemical treatment. Therefore, a simple approach would be desirable to develop bio-functionalized platforms for effectively modulating cell adhesion and consequently programming cell functionality without requiring any chemical or biological surface treatment. This study introduces a versatile yet simple laser approach to structure silicon (Si) chips into cytophobic/cytophilic patterns in order to modulate cell adhesion and proliferation. These patterns are fabricated on platforms through direct laser processing of Si substrates, which renders a desired computer-generated configuration into patterns. We investigate the morphology, chemistry, and wettability of the platform surfaces. Subsequently, we study the functionality of the fabricated platforms on modulating cervical cancer cells (HeLa) behaviour. The results from in vitro studies suggest that the nanostructures efficiently repel HeLa cells and drive them to migrate onto untreated sites. The study of the morphology of the cells reveals that cells evade the cytophobic area by bending and changing direction. Additionally, cell patterning, cell directionality, cell channelling, and cell trapping are achieved by developing different platforms with specific patterns. The flexibility and controllability of this approach to effectively structure Si substrates to cell-repulsive and cell-adhesive patterns offer perceptible outlook for developing bio-functionalized platforms for a variety of biomedical devices. Moreover, this approach could pave the way for developing anti-cancer platforms that selectively repel

  13. Tuning cell adhesion by direct nanostructuring silicon into cell repulsive/adhesive patterns

    Energy Technology Data Exchange (ETDEWEB)

    Premnath, Priyatha, E-mail: priyatha.premnath@ryerson.ca [Micro/Nanofabrication Laboratory, Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, Canada M5B 2K3 (Canada); Tavangar, Amirhossein, E-mail: atavanga@ryerson.ca [Micro/Nanofabrication Laboratory, Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, Canada M5B 2K3 (Canada); Tan, Bo, E-mail: tanbo@ryerson.ca [Nanocharacterization Laboratory, Department of Aerospace Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, Canada M5B 2K3 (Canada); Venkatakrishnan, Krishnan, E-mail: venkat@ryerson.ca [Micro/Nanofabrication Laboratory, Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, Canada M5B 2K3 (Canada)

    2015-09-10

    Developing platforms that allow tuning cell functionality through incorporating physical, chemical, or mechanical cues onto the material surfaces is one of the key challenges in research in the field of biomaterials. In this respect, various approaches have been proposed and numerous structures have been developed on a variety of materials. Most of these approaches, however, demand a multistep process or post-chemical treatment. Therefore, a simple approach would be desirable to develop bio-functionalized platforms for effectively modulating cell adhesion and consequently programming cell functionality without requiring any chemical or biological surface treatment. This study introduces a versatile yet simple laser approach to structure silicon (Si) chips into cytophobic/cytophilic patterns in order to modulate cell adhesion and proliferation. These patterns are fabricated on platforms through direct laser processing of Si substrates, which renders a desired computer-generated configuration into patterns. We investigate the morphology, chemistry, and wettability of the platform surfaces. Subsequently, we study the functionality of the fabricated platforms on modulating cervical cancer cells (HeLa) behaviour. The results from in vitro studies suggest that the nanostructures efficiently repel HeLa cells and drive them to migrate onto untreated sites. The study of the morphology of the cells reveals that cells evade the cytophobic area by bending and changing direction. Additionally, cell patterning, cell directionality, cell channelling, and cell trapping are achieved by developing different platforms with specific patterns. The flexibility and controllability of this approach to effectively structure Si substrates to cell-repulsive and cell-adhesive patterns offer perceptible outlook for developing bio-functionalized platforms for a variety of biomedical devices. Moreover, this approach could pave the way for developing anti-cancer platforms that selectively repel

  14. Relating Direct Methanol Fuel Cell Performance to Measurements in a Liquid Half Cell

    DEFF Research Database (Denmark)

    Pedersen, Christoffer Mølleskov; Tynelius, Oskar; Lund-Olesen, Torsten;

    2015-01-01

    allow further miniaturization or powering more advanced and more power hungry devices. The activity of fuel cell catalysts is often probed in the form of thin films in liquid half cells. However, it is challenging to mimic the conditions in an actual DMFC. On the other hand, it can also be problematic...... to extract the catalyst activity from a fuel cell measurement. In this work, we attempt to narrow the gap between fuel cell testing and liquid half-cell measurements. First, by placing a custom reference electrode within the fuel cell, we can determine the potential at the anode and cathode under in......-operando conditions. This in turn, allows us to directly correlate our measurements to those performed in a liquid half-cell at the same potential. For our half-cell measurements, we have tested different catalysts (Pt/C, PtRu/C) for the methanol oxidation reaction (MOR) and the oxygen reduction reaction (ORR...

  15. Evident?

    DEFF Research Database (Denmark)

    Plant, Peter

    2012-01-01

    Quality assurance and evidence in career guidance in Europe are often seen as self-evident approaches, but particular interests lie behind......Quality assurance and evidence in career guidance in Europe are often seen as self-evident approaches, but particular interests lie behind...

  16. A Mathematical Model of a Direct Propane Fuel Cell

    Directory of Open Access Journals (Sweden)

    Hamidreza Khakdaman

    2015-01-01

    Full Text Available A rigorous mathematical model for direct propane fuel cells (DPFCs was developed. Compared to previous models, it provides better values for the current density and the propane concentration at the exit from the anode. This is the first DPFC model to correctly account for proton transport based on the combination of the chemical potential gradient and the electrical potential gradient. The force per unit charge from the chemical potential gradient (concentration gradient that pushes protons from the anode to the cathode is greater than that from the electrical potential gradient that pushes them in the opposite direction. By including the chemical potential gradient, we learn that the proton concentration gradient is really much different than that predicted using the previous models that neglected the chemical potential gradient. Also inclusion of the chemical potential gradient made this model the first one having an overpotential gradient (calculated from the electrical potential gradient with the correct slope. That is important because the overpotential is exponentially related to the reaction rate (current density. The model described here provides a relationship between the conditions inside the fuel cell (proton concentration, overpotential and its performance as measured externally by current density and propane concentration.

  17. Direct coupling of a laser ablation cell to an AMS

    International Nuclear Information System (INIS)

    In rare cases, cleaned samples can be directly inserted into a negative ion source of an AMS and still meet the requirements for long-term and stable measurements. We present the coupling of a laser ablation system to the gas ion source of an AMS system (MICADAS, ETH Zurich) for direct and continuous CO2 introduction. Solid carbonate samples like stalagmites or corals are suitable sample materials, which can be ablated and decomposed continuously using a pulsed laser focused onto the surface of a solid sample, which is placed in an airtight ablation cell. CO2 formed during the ablation of a CaCO3 sample is continually flushed with He into the gas ion source. The production rate of CO2 can be adjusted via the laser pulse repetition rate (1–20 Hz), the crater diameter (1–150 μm) and the energy density applied (0.2–3 mJ/pulse) of the laser (frequency quintupled Nd:YAG at 213 nm with 5 ns pulse duration). In our first test, measurements of one sample with known age were replicated within one sigma. Blanks showed 5% contamination of modern carbon of yet unknown origin. In order to develop LA-AMS into a routine sampling tool the ablation cell geometry and settings of the gas ion source have to be further optimized.

  18. Direct Carbon Fuel Cell System Utilizing Solid Carbonaceous Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Turgut Gur

    2010-04-30

    This 1-year project has achieved most of its objective and successfully demonstrated the viability of the fluidized bed direct carbon fuel cell (FB-DCFC) approach under development by Direct Carbon technologies, LLC, that utilizes solid carbonaceous fuels for power generation. This unique electrochemical technology offers high conversion efficiencies, produces proportionately less CO{sub 2} in capture-ready form, and does not consume or require water for gasification. FB-DCFC employs a specialized solid oxide fuel cell (SOFC) arrangement coupled to a Boudouard gasifier where the solid fuel particles are fluidized and reacted by the anode recycle gas CO{sub 2}. The resulting CO is electrochemically oxidized at the anode. Anode supported SOFC structures employed a porous Ni cermet anode layer, a dense yttria stabilized zirconia membrane, and a mixed conducting porous perovskite cathode film. Several kinds of untreated solid fuels (carbon and coal) were tested in bench scale FBDCFC prototypes for electrochemical performance and stability testing. Single cells of tubular geometry with active areas up to 24 cm{sup 2} were fabricated. The cells achieved high power densities up to 450 mW/cm{sup 2} at 850 C using a low sulfur Alaska coal char. This represents the highest power density reported in the open literature for coal based DCFC. Similarly, power densities up to 175 mW/cm{sup 2} at 850 C were demonstrated with carbon. Electrical conversion efficiencies for coal char were experimentally determined to be 48%. Long-term stability of cell performance was measured under galvanostatic conditions for 375 hours in CO with no degradation whatsoever, indicating that carbon deposition (or coking) does not pose any problems. Similar cell stability results were obtained in coal char tested for 24 hours under galvanostatic conditions with no sign of sulfur poisoning. Moreover, a 50-cell planar stack targeted for 1 kW output was fabricated and tested in 95% CO (balance CO{sub 2

  19. Directing cell migration and organization via nanocrater-patterned cell-repellent interfaces

    Science.gov (United States)

    Jeon, Hojeong; Koo, Sangmo; Reese, Willie Mae; Loskill, Peter; Grigoropoulos, Costas P.; Healy, Kevin E.

    2015-09-01

    Although adhesive interactions between cells and nanostructured interfaces have been studied extensively, there is a paucity of data on how nanostructured interfaces repel cells by directing cell migration and cell-colony organization. Here, by using multiphoton ablation lithography to pattern surfaces with nanoscale craters of various aspect ratios and pitches, we show that the surfaces altered the cells’ focal-adhesion size and distribution, thus affecting cell morphology, migration and ultimately localization. We also show that nanocrater pitch can disrupt the formation of mature focal adhesions to favour the migration of cells towards higher-pitched regions, which present increased planar area for the formation of stable focal adhesions. Moreover, by designing surfaces with variable pitch but constant nanocrater dimensions, we were able to create circular and striped cellular patterns. Our surface-patterning approach, which does not involve chemical treatments and can be applied to various materials, represents a simple method to control cell behaviour on surfaces.

  20. Passive direct methanol fuel cells for portable electronic devices

    International Nuclear Information System (INIS)

    Due to the increasing demand for electricity, clean, renewable energy resources must be developed. Thus, the objective of the present study was to develop a passive direct methanol fuel cell (DMFC) for portable electronic devices. The power output of six dual DMFCs connected in series with an active area of 4 cm2 was approximately 600 mW, and the power density of the DMFCs was 25 mW cm-2. The DMFCs were evaluated as a power source for mobile phone chargers and media players. The results indicated that the open circuit voltage of the DMFC was between 6.0 V and 6.5 V, and the voltage under operating conditions was 4.0 V. The fuel cell was tested on a variety of cell phone chargers, media players and PDAs. The cost of energy consumption by the proposed DMFC was estimated to be USD 20 W-1, and the cost of methanol is USD 4 kW h. Alternatively, the local conventional electricity tariff is USD 2 kW h. However, for the large-scale production of electronic devices, the cost of methanol will be significantly lower. Moreover, the electricity tariff is expected to increase due to the constraints of fossil fuel resources and pollution. As a result, DMFCs will become competitive with conventional power sources.

  1. Multiple parameter monitoring in a direct methanol fuel cell

    International Nuclear Information System (INIS)

    Direct methanol fuel cells (DMFCs) are promising candidates for energy supply based on renewable sources. They provide a high power density and the possibility of an easy recharge. Moreover, the fuel storage is significantly easier than it is for hydrogen fuel cells. However, in continuous operation, supplying the anode with a constant concentration of methanol is the key to achieving stable and optimal performance. Hence, developing a method for measuring the methanol content of the fuel online is desirable for advanced monitoring of the fuel cell. In this work, we report the combined application of Raman spectroscopy, chronoamperometry and gravimetry for the simultaneous determination of the methanol concentration and the Faradaic efficiency in a DMFC. Raman spectroscopy is used to measure the actual methanol concentration supplied to the anode. The chronoamperometric and gravimetric measurements allow the theoretical methanol concentration, i.e. assuming that methanol is only consumed by electro-oxidation, to be determined. The full set of data ultimately facilitates the calculation of the Faradaic efficiency. (paper)

  2. Ultrasonic radiation to enable improvement of direct methanol fuel cell.

    Science.gov (United States)

    Wu, Chaoqun; Wu, Jiang; Luo, Hao; Wang, Sanwu; Chen, Tao

    2016-03-01

    To improve DMFC (direct methanol fuel cell) performance, a new method using ultrasonic radiation is proposed and a novel DMFC structure is designed and fabricated in the present paper. Three ultrasonic transducers (piezoelectric transducer, PZT) are integrated in the flow field plate to form the ultrasonic field in the liquid fuel. Ultrasonic frequency, acoustic power, and methanol concentration have been considered as variables in the experiments. With the help of ultrasonic radiation, the maximum output power and limiting current of cell can be independently increased by 30.73% and 40.54%, respectively. The best performance of DMFC is obtained at the condition of ultrasonic radiation (30 kHz and 4 W) fed with 2M methanol solution, because both its limiting current and output power reach their maximum value simultaneously (222 mA and 33.6 mW, respectively) under this condition. These results conclude that ultrasonic can be an alternative choice for improving the cell performance, and can facilitate a guideline for the optimization of DMFC. PMID:26585016

  3. SHAPE SELECTIVE NANOCATALYSTS FOR DIRECT METHANOL FUEL CELL APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Murph, S.

    2012-09-12

    While gold and platinum have long been recognized for their beauty and value, researchers at the Savannah River National Laboratory (SRNL) are working on the nano-level to use these elements for creative solutions to our nation's energy and security needs. Multiinterdisciplinary teams consisting of chemists, materials scientists, physicists, computational scientists, and engineers are exploring unchartered territories with shape-selective nanocatalysts for the development of novel, cost effective and environmentally friendly energy solutions to meet global energy needs. This nanotechnology is vital, particularly as it relates to fuel cells.SRNL researchers have taken process, chemical, and materials discoveries and translated them for technological solution and deployment. The group has developed state-of-the art shape-selective core-shell-alloy-type gold-platinum nanostructures with outstanding catalytic capabilities that address many of the shortcomings of the Direct Methanol Fuel Cell (DMFC). The newly developed nanostructures not only busted the performance of the platinum catalyst, but also reduced the material cost and overall weight of the fuel cell.

  4. Evidence to Support the Anti-Cancer Effect of Olive Leaf Extract and Future Directions

    Science.gov (United States)

    Boss, Anna; Bishop, Karen S.; Marlow, Gareth; Barnett, Matthew P. G.; Ferguson, Lynnette R.

    2016-01-01

    The traditional Mediterranean diet (MD) is associated with long life and lower prevalence of cardiovascular disease and cancers. The main components of this diet include high intake of fruit, vegetables, red wine, extra virgin olive oil (EVOO) and fish, low intake of dairy and red meat. Olive oil has gained support as a key effector of health benefits and there is evidence that this relates to the polyphenol content. Olive leaf extract (OLE) contains a higher quantity and variety of polyphenols than those found in EVOO. There are also important structural differences between polyphenols from olive leaf and those from olive fruit that may improve the capacity of OLE to enhance health outcomes. Olive polyphenols have been claimed to play an important protective role in cancer and other inflammation-related diseases. Both inflammatory and cancer cell models have shown that olive leaf polyphenols are anti-inflammatory and protect against DNA damage initiated by free radicals. The various bioactive properties of olive leaf polyphenols are a plausible explanation for the inhibition of progression and development of cancers. The pathways and signaling cascades manipulated include the NF-κB inflammatory response and the oxidative stress response, but the effects of these bioactive components may also result from their action as a phytoestrogen. Due to the similar structure of the olive polyphenols to oestrogens, these have been hypothesized to interact with oestrogen receptors, thereby reducing the prevalence and progression of hormone related cancers. Evidence for the protective effect of olive polyphenols for cancer in humans remains anecdotal and clinical trials are required to substantiate these claims idea. This review aims to amalgamate the current literature regarding bioavailability and mechanisms involved in the potential anti-cancer action of olive leaf polyphenols. PMID:27548217

  5. Novel sex cells and evidence for sex pheromones in diatoms.

    Directory of Open Access Journals (Sweden)

    Shinya Sato

    Full Text Available BACKGROUND: Diatoms belong to the stramenopiles, one of the largest groups of eukaryotes, which are primarily characterized by a presence of an anterior flagellum with tubular mastigonemes and usually a second, smooth flagellum. Based on cell wall morphology, diatoms have historically been divided into centrics and pennates, of which only the former have flagella and only on the sperm. Molecular phylogenies show the pennates to have evolved from among the centrics. However, the timing of flagellum loss--whether before the evolution of the pennate lineage or after--is unknown, because sexual reproduction has been so little studied in the 'araphid' basal pennate lineages, to which Pseudostaurosira belongs. METHODS/PRINCIPAL FINDING: Sexual reproduction of an araphid pennate, Pseudostaurosira trainorii, was studied with light microscopy (including time lapse observations and immunofluorescence staining observed under confocal scanning laser microscopy and SEM. We show that the species produces motile male gametes. Motility is mostly associated with the extrusion and retrieval of microtubule-based 'threads', which are structures hitherto unknown in stramenopiles, their number varying from one to three per cell. We also report experimental evidence for sex pheromones that reciprocally stimulate sexualization of compatible clones and orientate motility of the male gametes after an initial 'random walk'. CONCLUSIONS/SIGNIFICANCE: The threads superficially resemble flagella, in that both are produced by male gametes and contain microtubules. However, one striking difference is that threads cannot beat or undulate and have no motility of their own, and they do not bear mastigonemes. Threads are sticky and catch and draw objects, including eggs. The motility conferred by the threads is probably crucial for sexual reproduction of P. trainorii, because this diatom is non-motile in its vegetative stage but obligately outbreeding. Our pheromone experiments

  6. Evidence of the direct adsorption of mercury in human hair during occupational exposure to mercury vapour.

    Science.gov (United States)

    Queipo Abad, Silvia; Rodríguez-González, Pablo; García Alonso, J Ignacio

    2016-07-01

    We have found clear evidence of direct adsorption of mercury in human hair after the occupational exposure to mercury vapour. We have performed both longitudinal analysis of human hair by laser ablation ICP-MS and speciation analysis by gas chromatography ICP-MS in single hair strands of 5 individuals which were occupationally exposed to high levels of mercury vapour and showed acute mercury poisoning symptoms. Hair samples, between 3.5 and 11cm long depending on the individual, were taken ca. three months after exposure. Single point laser ablation samples of 50μm diameter were taken at 1mm intervals starting from the root of the hairs. Sulfur-34 was used as internal standard. The ratio (202)Hg/(34)S showed a distinct pattern of mercury concentration with much lower levels of mercury near the root of the hair and high levels of mercury near the end of the hair. In all cases a big jump in the concentration of mercury in hair occurred at a given distance from the root, between 32 and 42mm depending on the individual, with a high and almost constant concentration of mercury for longer distances to the root. When we took into account the rate of hair growth in humans, 9-15mm/month, the jump in mercury concentration agreed approximately with the dates when the contamination occurred with the new growing hair showing much lower mercury concentration. In some cases the concentration of mercury at the tip of the hair was ca. 1000 times higher than that near the root. Additionally, speciation studies confirmed that mercury in all hair samples was present as inorganic mercury. The only explanation for these results was the direct adsorption of mercury vapour in hair at the time of exposure. PMID:27259347

  7. Concave Urinary Crystallines: Direct Evidence of Calcium Oxalate Crystals Dissolution by Citrate In Vivo

    Directory of Open Access Journals (Sweden)

    Yun-Feng Shang

    2013-01-01

    Full Text Available The changes in urinary crystal properties in patients with calcium oxalate (CaOx calculi after oral administration of potassium citrate (K3cit were investigated via atomic force microscopy (AFM, scanning electron microscopy (SEM, X-ray powder diffractometry (XRD, and zeta potential analyzer. The AFM and SEM results showed that the surface of urinary crystals became concave, the edges and corners of crystals became blunt, the average size of urinary crystallines decreased significantly, and aggregation of urinary crystals was reduced. These changes were attributed to the significant increase in concentration of excreted citrate to  mg/L after K3cit intake from  mg/L before K3cit intake. After the amount of urinary citrate was increased, it complexed with Ca2+ ions on urinary crystals, which dissolved these crystals. Thus, the appearance of concave urinary crystals was a direct evidence of CaOx dissolution by citrate in vivo. The XRD results showed that the quantities and species of urinary crystals decreased after K3cit intake. The mechanism of inhibition of formation of CaOx stones by K3cit was possibly due to the complexation of Ca2+ with citrate, increase in urine pH, concentration of urinary inhibitor glycosaminoglycans (GAGs, and the absolute value of zeta potential after K3cit intake.

  8. Direct Evidence of Octupole Deformation in Neutron-Rich $^{144}$Ba

    CERN Document Server

    Bucher, B; Wu, C Y; Janssens, R V F; Cline, D; Hayes, A B; Albers, M; Ayangeakaa, A D; Butler, P A; Campbell, C M; Carpenter, M P; Chiara, C J; Clark, J A; Crawford, H L; Cromaz, M; David, H M; Dickerson, C; Gregor, E T; Harker, J; Hoffman, C R; Kay, B P; Kondev, F G; Korichi, A; Lauritsen, T; Macchiavelli, A O; Pardo, R C; Richard, A; Riley, M A; Savard, G; Scheck, M; Seweryniak, D; Smith, M K; Vondrasek, R; Wiens, A

    2016-01-01

    The neutron-rich nucleus $^{144}$Ba ($t_{1/2}$=11.5 s) is expected to exhibit some of the strongest octupole correlations among nuclei with mass numbers $A$ less than 200. Until now, indirect evidence for such strong correlations has been inferred from observations such as enhanced $E1$ transitions and interleaving positive- and negative-parity levels in the ground-state band. In this experiment, the octupole strength was measured directly by sub-barrier, multi-step Coulomb excitation of a post-accelerated 650-MeV $^{144}$Ba beam on a 1.0-mg/cm$^2$ $^{208}$Pb target. The measured value of the matrix element, $\\langle 3_1^- \\| \\mathcal{M}(E3) \\| 0_1^+ \\rangle=0.65(^{+17}_{-23})$ $e$b$^{3/2}$, corresponds to a reduced $B(E3)$ transition probability of 48($^{+25}_{-34}$) W.u. This result represents an unambiguous determination of the octupole collectivity, is larger than any available theoretical prediction, and is consistent with octupole deformation.

  9. Direct evidence for a Coulombic phase in monopole-suppressed SU(2) lattice gauge theory

    CERN Document Server

    Grady, Michael

    2013-01-01

    Further evidence is presented for the existence of a non-confining phase at weak coupling in SU(2) lattice gauge theory. Using Monte Carlo simulations with the standard Wilson action, gauge-invariant SO(3)-Z2 monopoles, which are strong-coupling lattice artifacts, have been seen to undergo a percolation transition exactly at the phase transition previously seen using Coulomb-gauge methods, with an infinite lattice critical point near $\\beta = 3.2$. The theory with both Z2 vortices and monopoles and SO(3)-Z2 monopoles eliminated is simulated in the strong coupling ($\\beta = 0$) limit on lattices up to $60^4$. Here, as in the high-$\\beta$ phase of the Wilson action theory, finite size scaling shows it spontaneously breaks the remnant symmetry left over after Coulomb gauge fixing. Such a symmetry breaking precludes the potential from having a linear term. The monopole restriction appears to prevent the transition to a confining phase at any $\\beta$. Direct measurement of the instantaneous Coulomb potential shows...

  10. Specific disgust processing in the left insula: New evidence from direct electrical stimulation.

    Science.gov (United States)

    Papagno, Costanza; Pisoni, Alberto; Mattavelli, Giulia; Casarotti, Alessandra; Comi, Alessandro; Fumagalli, Francesca; Vernice, Mirta; Fava, Enrica; Riva, Marco; Bello, Lorenzo

    2016-04-01

    Neuropsychological and neuroimaging studies yielded controversial results concerning the specific role of the insula in recognizing the facial expression of disgust. To verify whether the insula has a selective role in facial disgust processing, emotion recognition was studied in thirteen patients during intraoperative stimulation of the insula in awake surgery performed for removal of a glioma close to this structure. Direct electrical stimulation of the left insula produced a general decrease in emotion recognition but only in the case of disgust there was a statistically significant detrimental effect (p=0.004). Happiness and anger were the best and the worst recognized emotion, respectively. The worst baseline performance with anger and, partly, fear could be explained with the involvement of the left temporal regions, striatum, and the connection between the striatum and the frontal lobe, as suggested in previous studies. Therefore, upon these intra-operative evidences, we argue for a selective role of the left insula in disgust recognition, although a (non significant) decrease in the recognition of other negative emotions was found. However, additional networks can develop, as demonstrated by the fact that disgust recognition was not impaired after surgery even in patients with insular resection in the current as in previous studies. PMID:26836143

  11. First evidence of pep solar neutrinos by direct detection in Borexino

    Science.gov (United States)

    Galbiati, C.; Bellini, G.; Benziger, J.; Bick, D.; Bonetti, S.; Bonfini, G.; Bravo, D.; Buizza Avanzini, M.; Caccianiga, B.; Cadonati, L.; Calaprice, F.; Carraro, C.; Cavalcante, P.; Chavarria, A.; Dangelo, D.; Davini, S.; Derbin, A.; Etenko, A.; Fomenko, K.; Franco, D.; Galbiati, C.; Gazzana, S.; Ghiano, C.; Giammarchi, M.; Goeger-Neff, M.; Goretti, A.; Grandi, L.; Guardincerri, E.; Hardy, S.; Ianni, Aldo; Ianni, Andrea; Korablev, D.; Korga, G.; Koshio, Y.; Kryn, D.; Laubenstein, M.; Lewke, T.; Litvinovich, E.; Loer, B.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Machulin, I.; Manecki, S.; Maneschg, W.; Manuzio, G.; Meindl, Q.; Meroni, E.; Miramonti, L.; Misiaszek, M.; Montanari, D.; Mosteiro, P.; Muratova, V.; Oberauer, L.; Obolensky, M.; Ortica, F.; Otis, K.; Pallavicini, M.; Papp, L.; Perasso, L.; Perasso, S.; Pocar, A.; Quirk, J.; Raghavan, R. S.; Ranucci, G.; Razeto, A.; Re, A.; Romani, A.; Sabelnikov, A.; Saldanha, R.; Salvo, C.; Schönert, S.; Simgen, H.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Vignaud, D.; Vogelaar, R. B.; von Feilitzsch, F.; Winter, J.; Wojcik, M.; Wright, A.; Wurm, M.; Xu, J.; Zaimidoroga, O.; Zavatarelli, S.; Zuzel, G.; Borexino Collaboration

    2012-07-01

    We observed, for the first time, solar neutrinos in the 1.0-1.5 MeV energy range. We determined the rate of pep solar neutrino interactions in Borexino to be 3.l±0.6stat±0.3syst counts/(day-100 ton). Assuming the pep neutrino flux predicted by the Standard Solar Model, we obtained a constraint on the CNO solar neutrino interaction rate of techniques for the rejection of cosmogenic 11C, the dominant background in the 1-2 MeV region. Assuming the MSW-LMA solution to solar neutrino oscillations, these values correspond to solar neutrino fluxes of (1.6±0.3)×l08cm-2s-1 and <7.7×l08 cm-2s-1 (95% C.L.), respectively, in agreement with both the High and Low Metallicity Standard Solar Models. These results represent the first direct evidence of the pep neutrino signal and the strongest constraint of the CNO solar neutrino flux to date.

  12. Direct evidence for an evolving dust cloud from the exoplanet KIC 12557548 b

    CERN Document Server

    Bochinski, Jakub J; Marsh, Tom R; Dhillon, Vikram S; Littlefair, Stuart P

    2015-01-01

    We present simultaneous multi-color optical photometry using ULTRACAM of the transiting exoplanet KIC 12557548 b (also known as KIC 1255 b). This reveals, for the first time, the color dependence of the transit depth. Our g and z transits are similar in shape to the average Kepler short-cadence profile, and constitute the highest-quality extant coverage of individual transits. Our Night 1 transit depths are 0.85 +/- 0.04% in z; 1.00 +/- 0.03% in g; and 1.1 +/- 0.3% in u. We employ a residual-permutation method to assess the impact of correlated noise on the depth difference between the z and g bands and calculate the significance of the color dependence at 3.2{\\sigma}. The Night 1 depths are consistent with dust extinction as observed in the ISM, but require grain sizes comparable to the largest found in the ISM: 0.25-1{\\mu}m. This provides direct evidence in favor of this object being a disrupting low-mass rocky planet, feeding a transiting dust cloud. On the remaining four nights of observations the object ...

  13. GATA-1 directly regulates Nanog in mouse embryonic stem cells

    International Nuclear Information System (INIS)

    Nanog safeguards pluripotency in mouse embryonic stem cells (mESCs). Insight into the regulation of Nanog is important for a better understanding of the molecular mechanisms that control pluripotency of mESCs. In a silico analysis, we identify four GATA-1 putative binding sites in Nanog proximal promoter. The Nanog promoter activity can be significantly repressed by ectopic expression of GATA-1 evidenced by a promoter reporter assay. Mutation studies reveal that one of the four putative binding sites counts for GATA-1 repressing Nanog promoter activity. Direct binding of GATA-1 on Nanog proximal promoter is confirmed by electrophoretic mobility shift assay and chromatin immunoprecipitation. Our data provide new insights into the expanded regulatory circuitry that coordinates Nanog expression. - Highlights: • The Nanog proximal promoter conceives functional element for GATA-1. • GATA-1 occupies the Nanog proximal promoter in vitro and in vivo. • GATA-1 transcriptionally suppresses Nanog

  14. GATA-1 directly regulates Nanog in mouse embryonic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wen-Zhong; Ai, Zhi-Ying [College of Life Sciences, Northwest A& F University, Yangling 712100 (China); Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A& F University, Yangling 712100 (China); Wang, Zhi-Wei [School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027 (China); Chen, Lin-Lin [College of Life Sciences, Northwest A& F University, Yangling 712100 (China); Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A& F University, Yangling 712100 (China); Guo, Ze-Kun, E-mail: gzknwaf@126.com [College of Veterinary Medicine, Northwest A& F University, Yangling 712100 (China); Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A& F University, Yangling 712100 (China); Zhang, Yong, E-mail: zylabnwaf@126.com [College of Veterinary Medicine, Northwest A& F University, Yangling 712100 (China); Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A& F University, Yangling 712100 (China)

    2015-09-25

    Nanog safeguards pluripotency in mouse embryonic stem cells (mESCs). Insight into the regulation of Nanog is important for a better understanding of the molecular mechanisms that control pluripotency of mESCs. In a silico analysis, we identify four GATA-1 putative binding sites in Nanog proximal promoter. The Nanog promoter activity can be significantly repressed by ectopic expression of GATA-1 evidenced by a promoter reporter assay. Mutation studies reveal that one of the four putative binding sites counts for GATA-1 repressing Nanog promoter activity. Direct binding of GATA-1 on Nanog proximal promoter is confirmed by electrophoretic mobility shift assay and chromatin immunoprecipitation. Our data provide new insights into the expanded regulatory circuitry that coordinates Nanog expression. - Highlights: • The Nanog proximal promoter conceives functional element for GATA-1. • GATA-1 occupies the Nanog proximal promoter in vitro and in vivo. • GATA-1 transcriptionally suppresses Nanog.

  15. Reactivity descriptors for direct methanol fuel cell anode catalysts

    DEFF Research Database (Denmark)

    Ferrin, Peter; Nilekar, Anand Udaykumar; Greeley, Jeff;

    2008-01-01

    We have investigated the anode reaction in direct methanol fuel cells using a database of adsorption free energies for 16 intermediates on 12 close-packed transition metal surfaces calculated with periodic, self-consistent, density functional theory (DFT-GGA). This database, combined with a simple...... electrokinetic model of the methanol electrooxidation reaction, yields mechanistic insights that are consistent with previous experimental and theoretical studies on Pt, and extends these insights to a broad spectrum of other transition metals. In addition, by using linear scaling relations between the...... adsorption free energies of various intermediates in the reaction network, we find that the results determined with the full database of adsorption energies can be estimated by knowing only two key descriptors for each metal surface: the free energies of OH and CO on the surface. Two mechanisms for methanol...

  16. Direct Adaptive Aircraft Control Using Dynamic Cell Structure Neural Networks

    Science.gov (United States)

    Jorgensen, Charles C.

    1997-01-01

    A Dynamic Cell Structure (DCS) Neural Network was developed which learns topology representing networks (TRNS) of F-15 aircraft aerodynamic stability and control derivatives. The network is integrated into a direct adaptive tracking controller. The combination produces a robust adaptive architecture capable of handling multiple accident and off- nominal flight scenarios. This paper describes the DCS network and modifications to the parameter estimation procedure. The work represents one step towards an integrated real-time reconfiguration control architecture for rapid prototyping of new aircraft designs. Performance was evaluated using three off-line benchmarks and on-line nonlinear Virtual Reality simulation. Flight control was evaluated under scenarios including differential stabilator lock, soft sensor failure, control and stability derivative variations, and air turbulence.

  17. Direct and Indirect Role of Toll-Like Receptors in T Cell Mediated Immunity

    Institute of Scientific and Technical Information of China (English)

    DamoXu; HaiyingLiu; MousaKomai-Koma

    2004-01-01

    Toll-like receptors (TLR) are pathogen-associated molecular patterns (PAMPs) recognition receptors that play an important role in protective immunity against infection and inflammation. They act as central integrators of a wide variety of signals, responding to diverse agonists of microbial products. Stimulation of Toll-like receptors by microbial products leads to signaling pathways that activate not only innate, but also adaptive immunity by APC dependent or independent mechanisms. Recent evidence revealed that TLR signals played a determining role in the skewing of naive T cells towards either Thl or Th2 responses. Activation of Toll-like receptors also directly or indirectly influences regulatory T cell functions. Therefore, TLRs are required in both immune activation and immune regulation. Study of TLRs has significantly enhanced our understanding of innate and adaptive immune responses and provides novel therapeutic approaches against infectious and inflammatory diseases. Cellular & Molecular Immunology.

  18. Direct and Indirect Role of Toll-Like Receptors in T Cell Mediated Immunity

    Institute of Scientific and Technical Information of China (English)

    Damo Xu; Haiying Liu; Mousa Komai-Koma

    2004-01-01

    Toll-like receptors (TLR) are pathogen-associated molecular patterns (PAMPs) recognition receptors that play an important role in protective immunity against infection and inflammation. They act as central integrators of a wide variety of signals, responding to diverse agonists of microbial products. Stimulation of Toll-like receptors by microbial products leads to signaling pathways that activate not only innate, but also adaptive immunity by APC dependent or independent mechanisms. Recent evidence revealed that TLR signals played a determining role in the skewing of na(i)ve T cells towards either Th1 or Th2 responses. Activation of Toll-like receptors also directly or indirectly influences regulatory T cell functions. Therefore, TLRs are required in both immune activation and immune regulation. Study of TLRs has significantly enhanced our understanding of innate and adaptive immune responses and provides novel therapeutic approaches against infectious and inflammatory diseases.

  19. Infectious rotavirus enters cells by direct cell membrane penetration, not by endocytosis

    Energy Technology Data Exchange (ETDEWEB)

    Kaljot, K.T.; Shaw, R.D.; Greenberg, H.B. (Stanford Univ. School of Medicine, CA (USA) Palo Alto Veterans Administration Medical Center, CA (USA)); Rubin, D.H. (Univ. of Pennsylvania, Philadelphia (USA))

    1988-04-01

    Rotaviruses are icosahedral viruses with a segmented, double-stranded RNA genome. They are the major cause of severe infantile infectious diarrhea. Rotavirus growth in tissue culture is markedly enhanced by pretreatment of virus with trypsin. Trypsin activation is associated with cleavage of the viral hemagglutinin (viral protein 3 (VP3); 88 kilodaltons) into two fragments (60 and 28 kilodaltons). The mechanism by which proteolytic cleavage leads to enhanced growth is unknown. To determine whether trypsin treatment affected rotavirus internalization, the authors studied the kinetics of entry of infectious rhesus rotavirus (RRV) into MA104 cells. Trypsin-activated RRV was internalized with a half-time of 3 to 5 min, while nonactivated virus disappeared from the cell surface with a half-time of 30 to 50 min. In contrast to trypsin-activated RRV, loss of nonactivated RRV from the cell surface did not result in the appearance of infection, as measured by plaque formation. Purified trypsin-activated RRV added to cell monolayers at pH 7.4 mediated {sup 51}Cr, ({sup 14}C)choline, and ({sup 3}H)inositol released from prelabeled MA104 cells. This release could be specifically blocked by neutralizing antibodies to VP3. These results suggest that MA104 cell infection follows the rapid entry of trypsin-activated RRV by direct cell membrane penetration. Cell membrane penetration of infectious RRV is initiated by trypsin cleavage of VP3. Neutralizing antibodies can inhibit this direct membrane penetration.

  20. Recovery Act: Advanced Direct Methanol Fuel Cell for Mobile Computing

    Energy Technology Data Exchange (ETDEWEB)

    Fletcher, James H. [University of North Florida; Cox, Philip [University of North Florida; Harrington, William J [University of North Florida; Campbell, Joseph L [University of North Florida

    2013-09-03

    ABSTRACT Project Title: Recovery Act: Advanced Direct Methanol Fuel Cell for Mobile Computing PROJECT OBJECTIVE The objective of the project was to advance portable fuel cell system technology towards the commercial targets of power density, energy density and lifetime. These targets were laid out in the DOE’s R&D roadmap to develop an advanced direct methanol fuel cell power supply that meets commercial entry requirements. Such a power supply will enable mobile computers to operate non-stop, unplugged from the wall power outlet, by using the high energy density of methanol fuel contained in a replaceable fuel cartridge. Specifically this project focused on balance-of-plant component integration and miniaturization, as well as extensive component, subassembly and integrated system durability and validation testing. This design has resulted in a pre-production power supply design and a prototype that meet the rigorous demands of consumer electronic applications. PROJECT TASKS The proposed work plan was designed to meet the project objectives, which corresponded directly with the objectives outlined in the Funding Opportunity Announcement: To engineer the fuel cell balance-of-plant and packaging to meet the needs of consumer electronic systems, specifically at power levels required for mobile computing. UNF used existing balance-of-plant component technologies developed under its current US Army CERDEC project, as well as a previous DOE project completed by PolyFuel, to further refine them to both miniaturize and integrate their functionality to increase the system power density and energy density. Benefits of UNF’s novel passive water recycling MEA (membrane electrode assembly) and the simplified system architecture it enabled formed the foundation of the design approach. The package design was hardened to address orientation independence, shock, vibration, and environmental requirements. Fuel cartridge and fuel subsystems were improved to ensure effective fuel

  1. Dkk-1 Inhibits Intestinal Epithelial Cell Migration by Attenuating Directional Polarization of Leading Edge Cells

    Science.gov (United States)

    Koch, Stefan; Capaldo, Christopher T.; Samarin, Stanislav; Nava, Porfirio; Neumaier, Irmgard; Skerra, Arne; Sacks, David B.; Parkos, Charles A.

    2009-01-01

    Wnt signaling pathways regulate proliferation, motility, and survival in a variety of human cell types. Dickkopf-1 (Dkk-1) is a secreted Wnt antagonist that has been proposed to regulate tissue homeostasis in the intestine. In this report, we show that Dkk-1 is secreted by intestinal epithelial cells after wounding and that it inhibits cell migration by attenuating the directional orientation of migrating epithelial cells. Dkk-1 exposure induced mislocalized activation of Cdc42 in migrating cells, which coincided with a displacement of the polarity protein Par6 from the leading edge. Consequently, the relocation of the microtubule organizing center and the Golgi apparatus in the direction of migration was significantly and persistently inhibited in the presence of Dkk-1. Small interfering RNA-induced down-regulation of Dkk-1 confirmed that extracellular exposure to Dkk-1 was required for this effect. Together, these data demonstrate a novel role of Dkk-1 in the regulation of directional polarization of migrating intestinal epithelial cells, which contributes to the effect of Dkk-1 on wound closure in vivo. PMID:19776352

  2. Experimental investigation two phase flow in direct methanol fuel cells

    International Nuclear Information System (INIS)

    Direct methanol fuel cells (DMFC) have received many attentions specifically for portable electronic applications since it utilize methanol which is in liquid form in atmospheric condition and high energy density of the methanol. Thus it eliminates the storage problem of hydrogen. It also eliminates humidification requirement of polymeric membrane which is a problem in PEM fuel cells. Some electronic companies introduced DMFC prototypes for portable electronic applications. Presence of carbon dioxide gases due to electrochemical reactions in anode makes the problem a two phase problem. A two phase flow may occur at cathode specifically at high current densities due to the excess water. Presence of gas phase in anode region and liquid phase in cathode region prevents diffusion of fuel and oxygen to the reaction sites thus reduces the performance of the system. Uncontrolled pressure buildup in anode region increases methanol crossover through membrane and adversely effect the performance. Two phase flow in both anode and cathode region is very effective in the performance of DMYC system and a detailed understanding of two phase flow for high performance DMFC systems. Although there are many theoretical and experimental studies available on the DMFC systems in the literature, only few studies consider problem as a two-phase flow problem. In this study, an experimental set up is developed and species distributions on system are measured with a gas chromatograph. System performance characteristics (V-I curves) is measured depending on the process parameters (temperature, fuel ad oxidant flow rates, methanol concentration etc)

  3. Improved Flow-Field Structures for Direct Methanol Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Gurau, Bogdan

    2013-05-31

    The direct methanol fuel cell (DMFC) is ideal if high energy-density liquid fuels are required. Liquid fuels have advantages over compressed hydrogen including higher energy density and ease of handling. Although state-of-the-art DMFCs exhibit manageable degradation rates, excessive fuel crossover diminishes system energy and power density. Although use of dilute methanol mitigates crossover, the concomitant lowering of the gross fuel energy density (GFED) demands a complex balance-of-plant (BOP) that includes higher flow rates, external exhaust recirculation, etc. An alternative approach is redesign of the fuel delivery system to accommodate concentrated methanol. NuVant Systems Inc. (NuVant) will maximize the GFED by design and assembly of a DMFC that uses near neat methanol. The approach is to tune the diffusion of highly concentrated methanol (to the anode catalytic layer) to the back-diffusion of water formed at the cathode (i.e. in situ generation of dilute methanol at the anode layer). Crossover will be minimized without compromising the GFED by innovative integration of the anode flow-field and the diffusion layer. The integrated flow-field-diffusion-layers (IFDLs) will widen the current and potential DMFC operating ranges and enable the use of cathodes optimized for hydrogen-air fuel cells.

  4. New ETFE-based membrane for direct methanol fuel cell

    International Nuclear Information System (INIS)

    The investigated membranes are based on 35-bar μ m thick commercial poly(ethylene-alt-tetrafluoroethylene) (ETFE) films. The films were made proton conductive by means of irradiation treatment followed by sulfonation. These membranes have exceptionally low water uptake and excellent dimensional stability. The new membranes are investigated widely in a laboratory-scale direct methanol fuel cell (DMFC). The temperature range used in the fuel cell tests was 30-85-bar o C and the measurement results were compared to those of the Nafion(R)115 membrane. Also methanol permeability through the ETFE-based membrane was measured as a function of temperature, resulting in values less than 10% of the corresponding values for Nafion(R)115, which was considerably thicker than the experimental membrane. Methanol crossover was reported to decrease when the thickness of the membrane increases, so the ETFE-based membrane compares favourably to Nafion(R) membranes. The maximum power densities achieved with the experimental ETFE-based membrane were about 40-65% lower than the corresponding values of the Nafion(R)115 membrane, because of the lower conductivity and noticeably higher IR-losses. Chemical and mechanical stability of the ETFE-based membrane appeared to be promising since it was tested over 2000-bar h in the DMFC without any performance loss

  5. Improved Cathode Structure for a Direct Methanol Fuel Cell

    Science.gov (United States)

    Valdez, Thomas; Narayanan, Sekharipuram

    2005-01-01

    An improved cathode structure on a membrane/electrode assembly has been developed for a direct methanol fuel cell, in a continuing effort to realize practical power systems containing such fuel cells. This cathode structure is intended particularly to afford better cell performance at a low airflow rate. A membrane/electrode assembly of the type for which the improved cathode structure was developed (see Figure 1) is fabricated in a process that includes brush painting and spray coating of catalyst layers onto a polymer-electrolyte membrane and onto gas-diffusion backings that also act as current collectors. The aforementioned layers are then dried and hot-pressed together. When completed, the membrane/electrode assembly contains (1) an anode containing a fine metal black of Pt/Ru alloy, (2) a membrane made of Nafion 117 or equivalent (a perfluorosulfonic acid-based hydrophilic, proton-conducting ion-exchange polymer), (3) a cathode structure (in the present case, the improved cathode structure described below), and (4) the electrically conductive gas-diffusion backing layers, which are made of Toray 060(TradeMark)(or equivalent) carbon paper containing between 5 and 6 weight percent of poly(tetrafluoroethylene). The need for an improved cathode structure arises for the following reasons: In the design and operation of a fuel-cell power system, the airflow rate is a critical parameter that determines the overall efficiency, cell voltage, and power density. It is desirable to operate at a low airflow rate in order to obtain thermal and water balance and to minimize the size and mass of the system. The performances of membrane/electrode assemblies of prior design are limited at low airflow rates. Methanol crossover increases the required airflow rate. Hence, one way to reduce the required airflow rate is to reduce the effect of methanol crossover. Improvement of the cathode structure - in particular, addition of hydrophobic particles to the cathode - has been

  6. Turgor Regulation in Osmotically Stressed Arabidopsis Epidermal Root Cells. Direct Support for the Role of Inorganic Ion Uptake as Revealed by Concurrent Flux and Cell Turgor Measurements1

    Science.gov (United States)

    Shabala, Sergey N.; Lew, Roger R.

    2002-01-01

    Hyperosmotic stress is known to significantly enhance net uptake of inorganic ions into plant cells. Direct evidence for cell turgor recovery via such a mechanism, however, is still lacking. In the present study, we performed concurrent measurements of net ion fluxes (with the noninvasive microelectrode ion flux estimation technique) and cell turgor changes (with the pressure-probe technique) to provide direct evidence that inorganic ion uptake regulates turgor in osmotically stressed Arabidopsis epidermal root cells. Immediately after onset of hyperosmotic stress (100/100 mm mannitol/sorbitol treatment), the cell turgor dropped from 0.65 to about 0.25 MPa. Turgor recovery started within 2 to 10 min after the treatment and was accompanied by a significant (30–80 nmol m−2 s−1) increase in uptake of K+, Cl−, and Na+ by root cells. In most cells, almost complete (>90% of initial values) recovery of the cell turgor was observed within 40 to 50 min after stress onset. In another set of experiments, we combined the voltage-clamp and the microelectrode ion flux estimation techniques to show that this process is, in part, mediated by voltage-gated K+ transporters at the cell plasma membrane. The possible physiological significance of these findings is discussed. PMID:12011359

  7. Evidences Suggesting Involvement of Viruses in Oral Squamous Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Kanupriya Gupta

    2013-01-01

    Full Text Available Oral cancer is one of the most common cancers and it constitutes a major health problem particularly in developing countries. Oral squamous cell carcinoma (OSCC represents the most frequent of all oral neoplasms. Several risk factors have been well characterized to be associated with OSCC with substantial evidences. The etiology of OSCC is complex and involves many factors. The most clearly defined potential factors are smoking and alcohol, which substantially increase the risk of OSCC. However, despite this clear association, a substantial proportion of patients develop OSCC without exposure to them, emphasizing the role of other risk factors such as genetic susceptibility and oncogenic viruses. Some viruses are strongly associated with OSCC while the association of others is less frequent and may depend on cofactors for their carcinogenic effects. Therefore, the exact role of viruses must be evaluated with care in order to improve the diagnosis and treatment of OSCC. Although a viral association within a subset of OSCC has been shown, the molecular and histopathological characteristics of these tumors have yet to be clearly defined.

  8. Direct effects of music in non-auditory cells in culture

    Directory of Open Access Journals (Sweden)

    Nathalia dos Reis Lestard

    2013-01-01

    Full Text Available The biological effects of electromagnetic waves are widely studied, especially due to their harmful effects, such as radiation-induced cancer and to their application in diagnosis and therapy. However, the biological effects of sound, another physical agent to which we are frequently exposed have been considerably disregarded by the scientific community. Although a number of studies suggest that emotions evoked by music may be useful in medical care, alleviating stress and nociception in patients undergoing surgical procedures as well as in cancer and burned patients, little is known about the mechanisms by which these effects occur. It is generally accepted that the mechanosensory hair cells in the ear transduce the sound-induced mechanical vibrations into neural impulses, which are interpreted by the brain and evoke the emotional effects. In the last decade; however, several studies suggest that the response to music is even more complex. Moreover, recent evidence comes out that cell types other than auditory hair cells could response to audible sound. However, what is actually sensed by the hair cells, and possible by other cells in our organism, are physical differences in fluid pressure induced by the sound waves. Therefore, there is no reasonable impediment for any cell type of our body to respond to a pure sound or to music. Hence, the aim of the present study was to evaluate the response of a human breast cancer cell line, MCF7, to music. The results′ obtained suggest that music can alter cellular morpho-functional parameters, such as cell size and granularity in cultured cells. Moreover, our results suggest for the 1 st time that music can directly interfere with hormone binding to their targets, suggesting that music or audible sounds could modulate physiological and pathophysiological processes.

  9. Direct effects of music in non-auditory cells in culture.

    Science.gov (United States)

    Lestard, Nathalia Dos Reis; Valente, Raphael C; Lopes, Anibal G; Capella, Márcia A M

    2013-01-01

    The biological effects of electromagnetic waves are widely studied, especially due to their harmful effects, such as radiation-induced cancer and to their application in diagnosis and therapy. However, the biological effects of sound, another physical agent to which we are frequently exposed have been considerably disregarded by the scientific community. Although a number of studies suggest that emotions evoked by music may be useful in medical care, alleviating stress and nociception in patients undergoing surgical procedures as well as in cancer and burned patients, little is known about the mechanisms by which these effects occur. It is generally accepted that the mechanosensory hair cells in the ear transduce the sound-induced mechanical vibrations into neural impulses, which are interpreted by the brain and evoke the emotional effects. In the last decade; however, several studies suggest that the response to music is even more complex. Moreover, recent evidence comes out that cell types other than auditory hair cells could response to audible sound. However, what is actually sensed by the hair cells, and possible by other cells in our organism, are physical differences in fluid pressure induced by the sound waves. Therefore, there is no reasonable impediment for any cell type of our body to respond to a pure sound or to music. Hence, the aim of the present study was to evaluate the response of a human breast cancer cell line, MCF7, to music. The results' obtained suggest that music can alter cellular morpho-functional parameters, such as cell size and granularity in cultured cells. Moreover, our results suggest for the 1 st time that music can directly interfere with hormone binding to their targets, suggesting that music or audible sounds could modulate physiological and pathophysiological processes. PMID:23955127

  10. Direct evidence of histopathological impacts of wastewater discharge on resident Antarctic fish (Trematomus bernacchii) at Davis Station, East Antarctica

    International Nuclear Information System (INIS)

    Highlights: • Histological alteration in Antarctic cod exposed to wastewater from Davis Station. • Severity of gill and liver pathologies directly related to proximity to outfall. • Prevalence and severity of alteration decreased with distance from the outfall. • Higher level of treatment required to minimise impacts to marine environment. - Abstract: During the 2009/2010 summer, a comprehensive environmental impact assessment (EIA) of the wastewater discharge at Davis Station, East Antarctica was completed. As part of this, histological alteration of gill and liver tissue in Antarctic Rock-cod (Trematomus bernacchii) from four sites along a spatial gradient from the wastewater outfall were assessed. All fish within 800 m of the outfall exhibited significant histological changes in both tissues. Common pathologies observed in fish closest to the outfall include proliferation of epithelial cells with associated secondary lamellar fusion in the gills and multifocal granulomata with inflammation and necrosis as well as cysts in the liver. Fish from sites >800 m from the outfall also exhibited alterations but to a lesser degree, with prevalence and severity decreasing with increasing distance from the outfall. This study highlights the value of histopathological investigations as part of EIAs and provides the first evidence of sub-lethal alteration associated with wastewater discharge in East Antarctica

  11. Development of a Direct Carbon Fuel Cell for Power and Fuels Cogeneration Directly from Plastic Trash Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This small business innovation research is intended to develop a simple processing concept based-on an advanced direct carbon fuel cell (DCFC) technology enabling...

  12. Direct evidence for a Coulombic phase in monopole-suppressed SU(2) lattice gauge theory

    International Nuclear Information System (INIS)

    Further evidence is presented for the existence of a non-confining phase at weak coupling in SU(2) lattice gauge theory. Using Monte Carlo simulations with the standard Wilson action, gauge-invariant SO(3)–Z2 monopoles, which are strong-coupling lattice artifacts, have been seen to undergo a percolation transition exactly at the phase transition previously seen using Coulomb gauge methods, with an infinite lattice critical point near β=3.2. The theory with both Z2 vortices and monopoles and SO(3)–Z2 monopoles eliminated is simulated in the strong-coupling (β=0) limit on lattices up to 604. Here, as in the high-β phase of the Wilson-action theory, finite size scaling shows it spontaneously breaks the remnant symmetry left over after Coulomb gauge fixing. Such a symmetry breaking precludes the potential from having a linear term. The monopole restriction appears to prevent the transition to a confining phase at any β. Direct measurement of the instantaneous Coulomb potential shows a Coulombic form with moderately running coupling possibly approaching an infrared fixed point of α∼1.4. The Coulomb potential is measured to 50 lattice spacings and 2 fm. A short-distance fit to the 2-loop perturbative potential is used to set the scale. High precision at such long distances is made possible through the use of open boundary conditions, which was previously found to cut random and systematic errors of the Coulomb gauge fixing procedure dramatically. The Coulomb potential agrees with the gauge-invariant interquark potential measured with smeared Wilson loops on periodic lattices as far as the latter can be practically measured with similar statistics data

  13. Population-Level Impact of Ontario's Infant Rotavirus Immunization Program: Evidence of Direct and Indirect Effects.

    Directory of Open Access Journals (Sweden)

    Sarah E Wilson

    Full Text Available To evaluate the direct and indirect population impact of rotavirus (RV immunization on hospitalizations and emergency department (ED visits for acute gastroenteritis (AGE in Ontario before and after the publicly-funded RV immunization program.Administrative data was used to identify ED visits and hospitalizations for all Ontarians using ICD-10 codes. We used two outcome definitions: RV-specific AGE (RV-AGE and codes representing RV-, other viral and cause unspecified AGE ("overall AGE". The pre-program and public program periods were August 1, 2005 to July 31, 2011; and August 1, 2011 to March 31, 2013, respectively. A negative binominal regression model that included the effect of time was used to calculate rates and rate ratios (RRs and 95% confidence intervals (CIs for RV-AGE and overall AGE between periods, after adjusting for age, seasonality and secular trends. Analyses were conducted for all ages combined and age stratified.Relative to the pre-program period, the adjusted RRs for RV-AGE and overall AGE hospitalizations in the public program period were 0.29 (95%CI: 0.22-0.39 and 0.68 (95%CI: 0.62-0.75, respectively. Significant reductions in RV-AGE hospitalizations were noted overall and for the following age bands: = 65 years (RR 0.80, 95%CI: 0.72-0.90. The program was associated with adjusted RRs of 0.32 (95% CI: 0.20-0.52 for RV-AGE ED visits and 0.90 (95% CI: 0.85-0.96 for overall AGE ED visits.This large, population-based study provides evidence of the impact of RV vaccine in preventing hospitalizations and ED visits for RV-AGE and overall AGE, including herd effects.

  14. PLASMA OXYTOCIN CONCENTRATION AND DEPRESSIVE SYMPTOMS: A REVIEW OF CURRENT EVIDENCE AND DIRECTIONS FOR FUTURE RESEARCH.

    Science.gov (United States)

    Massey, Suena H; Backes, Katherine A; Schuette, Stephanie A

    2016-04-01

    There is substantial recent interest in the role of oxytocin in social and affiliative behaviors-animal models of depression have suggested a link between oxytocin and mood. We reviewed literature to date for evidence of a potential relationship between peripheral oxytocin concentration and depressive symptoms in humans. Pubmed(®) and PsychINFO(®) were searched for biomedical and social sciences literature from 1960 to May 19, 2015 for empirical articles in English involving human subjects focused on the relationship between peripheral oxytocin concentration and depressive symptoms, excluding articles on the oxytocin receptor gene, or involving exogenous (i.e. intranasal) administration of oxytocin. Eight studies meeting criteria were identified and formally reviewed. Studies of pregnant women suggested an inverse relationship between oxytocin level and depressive symptom severity. Findings in nonpregnant women were broadly consistent with the role of oxytocin release in response to stress supported by animal studies. The relationship between oxytocin and depression in men appeared to be in the opposite direction, possibly reflecting the influence of gonadal hormones on oxytocinergic functioning found in other mammalian species. Overall, small sample sizes, heterogeneity in study designs, and other methodological limitations may account for inconsistent findings. Future research utilizing reliable oxytocin measurement protocols including measurements across time, larger sample sizes, and sample homogeneity with respect to multiple possible confounders (age, gender, race and ethnicity, ovarian status among women, and psychosocial context) are needed to elucidate the role of oxytocin in the pathogenesis of depression, and could guide the design of novel pharmacologic agents. PMID:26756305

  15. Evidence for a retinal velocity memory underlying the direction of anticipatory smooth pursuit eye movements.

    Science.gov (United States)

    Murdison, T Scott; Paré-Bingley, Chanel A; Blohm, Gunnar

    2013-08-01

    To compute spatially correct smooth pursuit eye movements, the brain uses both retinal motion and extraretinal signals about the eyes and head in space (Blohm and Lefèvre 2010). However, when smooth eye movements rely solely on memorized target velocity, such as during anticipatory pursuit, it is unknown if this velocity memory also accounts for extraretinal information, such as head roll and ocular torsion. To answer this question, we used a novel behavioral updating paradigm in which participants pursued a repetitive, spatially constant fixation-gap-ramp stimulus in series of five trials. During the first four trials, participants' heads were rolled toward one shoulder, inducing ocular counterroll (OCR). With each repetition, participants increased their anticipatory pursuit gain, indicating a robust encoding of velocity memory. On the fifth trial, they rolled their heads to the opposite shoulder before pursuit, also inducing changes in ocular torsion. Consequently, for spatially accurate anticipatory pursuit, the velocity memory had to be updated across changes in head roll and ocular torsion. We tested how the velocity memory accounted for head roll and OCR by observing the effects of changes to these signals on anticipatory trajectories of the memory decoding (fifth) trials. We found that anticipatory pursuit was updated for changes in head roll; however, we observed no evidence of compensation for OCR, representing the absence of ocular torsion signals within the velocity memory. This indicated that the directional component of the memory must be coded retinally and updated to account for changes in head roll, but not OCR. PMID:23678014

  16. Direct Evidence of Cold Gas in DLA 0812+32B

    Science.gov (United States)

    Jorgenson, Regina A.; Wolfe, Arthur M.; Prochaska, J. Xavier; Carswell, Robert F.

    2009-10-01

    We present the first direct evidence for cold gas in a high redshift DLA galaxy. We measured several multiplets of weak neutral carbon (C I) transitions in order to perform a curve of growth analysis. A Δ χ2 test constrains the best-fit Doppler parameter, b = 0.33+0.05 -0.04 km s-1 and log N(C I) = 13.30 ± 0.2 cm-2. This Doppler parameter constrains the kinetic temperature of the gas to T <= 78 K (T <= 115 K, 2σ). We used the associated C I fine structure lines to constrain the volume density of the gas, n(H I) ~40-200 cm-3 (2σ), resulting in a lower limit on the cloud size of approximately 0.1-1 parsec. While it is difficult to determine the metallicity of the cold component, the absence of Cr II indicates that the cold cloud suffers a high level of dust depletion. Additionally, the large amount of Lyman and Werner-band molecular hydrogen absorption (log N(H2)total = 19.88 cm-2, f _H_2 ≥ 0.06) with an excitation temperature of T ex = 46 K as determined by the rotational J = 0 and J = 1 states, is consistent with the presence of cold gas. We propose that this cloud may be gravitationally confined and may represent a transition gas phase from primarily neutral atomic gas, to a colder, denser molecular phase that will eventually host star formation.

  17. No Evidence Linking Cell Phone Use to Risk of Brain Tumors

    Science.gov (United States)

    ... Blood & Biologics Articulos en Espanol No Evidence Linking Cell Phone Use to Risk of Brain Tumors Printer-friendly ... Minimizing RF Exposure Do the radio waves that cell phones emit pose a threat to health? Although research ...

  18. Direct fuel cell power plants: the final steps to commercialization

    Science.gov (United States)

    Glenn, Donald R.

    Since the last paper presented at the Second Grove Fuel Cell Symposium, the Energy Research Corporation (ERC) has established two commercial subsidiaries, become a publically-held firm, expanded its facilities and has moved the direct fuel cell (DFC) technology and systems significantly closer to commercial readiness. The subsidiaries, the Fuel Cell Engineering Corporation (FCE) and Fuel Cell Manufacturing Corporation (FCMC) are perfecting their respective roles in the company's strategy to commercialize its DFC technology. FCE is the prime contractor for the Santa Clara Demonstration and is establishing the needed marketing, sales, engineering, and servicing functions. FCMC in addition to producing the stacks and stack modules for the Santa Clara demonstration plant is now upgrading its production capability and product yields, and retooling for the final stack scale-up for the commercial unit. ERC has built and operated the tallest and largest capacities-to-date carbonate fuel cell stacks as well as numerous short stacks. While most of these units were tested at ERC's Danbury, Connecticut (USA) R&D Center, others have been evaluated at other domestic and overseas facilities using a variety of fuels. ERC has supplied stacks to Elkraft and MTU for tests with natural gas, and RWE in Germany where coal-derived gas were used. Additional stack test activities have been performed by MELCO and Sanyo in Japan. Information from some of these activities is protected by ERC's license arrangements with these firms. However, permission for limited data releases will be requested to provide the Grove Conference with up-to-date results. Arguably the most dramatic demonstration of carbonate fuel cells in the utility-scale, 2 MW power plant demonstration unit, located in the City of Santa Clara, California. Construction of the unit's balance-of-plant (BOP) has been completed and the installed equipment has been operationally checked. Two of the four DFC stack sub-modules, each

  19. TGF-β-Induced Regulatory T Cells Directly Suppress B Cell Responses through a Noncytotoxic Mechanism.

    Science.gov (United States)

    Xu, Anping; Liu, Ya; Chen, Weiqian; Wang, Julie; Xue, Youqiu; Huang, Feng; Rong, Liming; Lin, Jin; Liu, Dahai; Yan, Mei; Li, Quan-Zhen; Li, Bin; Song, Jianxun; Olsen, Nancy; Zheng, Song Guo

    2016-05-01

    Foxp3(+) regulatory T cells (Treg) playing a crucial role in the maintenance of immune tolerance and prevention of autoimmune diseases consist of thymus-derived naturally occurring CD4(+)Foxp3(+) Treg cells (nTreg) and those that can be induced ex vivo with TGF-β (iTreg). Although both Treg subsets share similar phenotypes and functional characteristics, they also have potential biologic differences on their biology. The role of iTreg in regulating B cells remains unclear so far. The suppression assays of Treg subsets on activation, proliferation, and Abs production of B cells were measured using a Treg and B cell coculture system in vitro. Transwell and Ab blockade experiments were performed to assess the roles of cell contact and soluble cytokines. Treg were adoptively transferred to lupus mice to assess in vivo effects on B cells. Like nTreg, iTreg subset also directly suppressed activation and proliferation of B cells. nTreg subset suppressed B cell responses through cytotoxic manner related to expression of granzyme A, granzyme B, and perforin, whereas the role of iTreg subset on B cells did not involve in cytotoxic action but depending on TGF-β signaling. Furthermore, iTreg subset can significantly suppress Ab produced by lupus B cells in vitro. Comparison experiments using autoantibodies microarrays demonstrated that adoptive transfer of iTreg had a superior effect than nTreg subset on suppressing lupus B cell responses in vivo. Our data implicate a role and advantage of iTreg subset in treating B cell-mediated autoimmune diseases, boosting the translational potential of these findings. PMID:27001954

  20. Nano-Engineered Catalysts for Direct Methanol Fuel Cells

    Science.gov (United States)

    Myung, Nosang; Narayanan, Sekharipuram; Wiberg, Dean

    2008-01-01

    Nano-engineered catalysts, and a method of fabricating them, have been developed in a continuing effort to improve the performances of direct methanol fuel cells as candidate power sources to supplant primary and secondary batteries in a variety of portable electronic products. In order to realize the potential for high energy densities (as much as 1.5 W h/g) of direct methanol fuel cells, it will be necessary to optimize the chemical compositions and geometric configurations of catalyst layers and electrode structures. High performance can be achieved when catalyst particles and electrode structures have the necessary small feature sizes (typically of the order of nanometers), large surface areas, optimal metal compositions, high porosity, and hydrophobicity. The present method involves electrodeposition of one or more catalytic metal(s) or a catalytic-metal/polytetrafluoroethylene nanocomposite on an alumina nanotemplate. The alumina nanotemplate is then dissolved, leaving the desired metal or metal/polytetrafluoroethylene-composite catalyst layer. Unlike some prior methods of making fine metal catalysts, this method does not involve processing at elevated temperature; all processing can be done at room temperature. In addition, this method involves fewer steps and is more amenable to scaling up for mass production. Alumina nanotemplates are porous alumina membranes that have been fabricated, variously, by anodizing either pure aluminum or aluminum that has been deposited on silicon by electronbeam evaporation. The diameters of the pores (7 to 300 nm), areal densities of pores (as much as 7 x 10(exp 10)sq cm), and lengths of pores (up to about 100 nm) can be tailored by selection of fabrication conditions. In a given case, the catalytic metal, catalytic metal alloy, or catalytic metal/ polytetrafluoroethylene composite is electrodeposited in the pores of the alumina nanotemplate. The dimensions of the pores, together with the electrodeposition conditions

  1. 7 CFR 1412.34 - Submitting production evidence for establishing direct payment yields for oilseeds and pulse crops.

    Science.gov (United States)

    2010-01-01

    ... direct payment yields for oilseeds and pulse crops. 1412.34 Section 1412.34 Agriculture Regulations of... oilseeds and pulse crops. (a)(1) Reports of production evidence must be submitted when the owner elects to... 30, 2007, and pulse crops for the farm in accordance with § 1412.32. (2) Producer or...

  2. X-ray Cavities in Galaxy Groups and Clusters: Central Gas Entropy Excess as Direct Evidence for AGN Feedback

    Indian Academy of Sciences (India)

    Yu Wang

    2011-03-01

    Observations of X-ray jets and cavities in clusters of galaxies observed by Chandra are briefly reviewed. A recent study on the excess of central gas entropy, which can be considered as direct evidence for AGN feedback in galaxy groups and clusters is presented. An expanded account of this study has been presented in RAA (Wang et al. 2010).

  3. Effectiveness of female controlled barrier methods in preventing sexually transmitted infections and HIV: current evidence and future research directions

    OpenAIRE

    Minnis, A; Padian, N

    2005-01-01

    Objectives: To evaluate evidence for the effectiveness of female controlled physical and chemical barrier methods in preventing STI/HIV transmission, to examine recent reviews on microbicide development, and to highlight promising research directions. To discuss challenges in conducting effectiveness research and in translating results to public health intervention.

  4. Computational modeling of a direct propane fuel cell

    Science.gov (United States)

    Khakdaman, H.; Bourgault, Y.; Ternan, M.

    2011-03-01

    The first two dimensional mathematical model of a complete direct propane fuel cell (DPFC) is described. The governing equations were solved using FreeFem software that uses finite element methods. Robin boundary conditions were used to couple the anode, membrane, and cathode sub-domains successfully. The model showed that a polytetrafluoroethylene membrane having its pores filled with zirconium phosphate (ZrP-PTFE), in a DPFC at 150 °C performed much the same as other electrolytes; Nafion, aqueous H3PO4, and H2SO4 doped polybenzimidazole, when they were used in DPFCs. One advantage of a ZrP-PTFE at 150 °C is that it operates without liquid phase water. As a result corrosion will be much less severe and it may be possible for non-precious metal catalysts to be used. Computational results showed that the thickness of the catalyst layer could be increased sufficiently so that the pressure drop between the reactant and product channels of the interdigitated flow fields is small. By increasing the width of the land and therefore the reactant's contact time with the catalyst it was possible to approach 100% propane conversion. Therefore fuel cell operation with a minimum concentration of propane in the product stream should be possible. Finally computations of the electrical potential in the ZrP phase, the electron flux in the Pt/C phase, and the overpotential in both the anode and cathode catalyst layers showed that serious errors in the model occurred because proton diffusion, caused by the proton concentration gradient, was neglected in the equation for the conservation of protons.

  5. Primary study on directed differentiation of embryonic stem cells into thyrocyte-like cells in vitro

    International Nuclear Information System (INIS)

    Objective: To investigate the feasibility of directed differentiation of embryonic stem cells (ESCs) into thyrocyte-like cells in vitro. Methods: Murine E14 ESCs were cultured in methylcellulose semisolid medium to form embryoid bodies (EBs). These EBs were transferred for further inductive culture with the stepwise addition of growth factors (TSH, insulin and KI) into the culture medium. During differentiation, cell morphology was observed through phase contrast microscopy and compared with the normal thyroid cells from mouse. The molecular markers of thyroid cells were performed by indirect immunofluorescent analysis under fluorescent microscopy. Gene expressions of thyroid specific mRNA were analyzed by RT-PCR for molecules TSH receptor (TSHR), paired box gene 8 (PAX8), sodium iodide symporter (NIS), thyroid peroxidase (TPO) and thyroglobulin (Tg). Results: After EBs formation, on day six of further culture added with inductive factors TSH, insulin and KI, ESCs-derived cells expressed thyroid-specific genes such as PAX8, NIS, TPO, Tg and TSHR. On the 8th day, these ESCs-derived thyrocyte-like cells overexpressed TSHR, thyroid transcription factor-1 (TTF-1) whereas PAX8, thyroid transcription factor-2 (TTF-2) remained in a housekeeping level. On the 10th day, all the molecular markers (including TSHR, PAX8, NIS, TPO and Tg) were overexpressed. Morphology of these markers positive differentiated cells was similar to those normal thyroid cells. Conclusions: ESCs can differentiate into thyrocyte-like cells under certain inductive conditions and is possibly related to growth factors in vitro. This study suggests that a renewable source of thyroid follicular cells derived from ESCs holds great therapeutic potential for future cell replacement therapy in clinic. (authors)

  6. Direct Monitoring of Nucleotide Turnover in Human Cell Extracts and Cells by Fluorogenic ATP Analogs.

    Science.gov (United States)

    Hacker, Stephan M; Buntz, Annette; Zumbusch, Andreas; Marx, Andreas

    2015-11-20

    Nucleotides containing adenosine play pivotal roles in every living cell. Adenosine triphosphate (ATP), for example, is the universal energy currency, and ATP-consuming processes also contribute to posttranslational protein modifications. Nevertheless, detecting the turnover of adenosine nucleotides in the complex setting of a cell remains challenging. Here, we demonstrate the use of fluorogenic analogs of ATP and adenosine tetraphosphate to study nucleotide hydrolysis in lysates of human cell lines and in intact human cells. We found that the adenosine triphosphate analog is completely stable in lysates of human cell lines, whereas the adenosine tetraphosphate analog is rapidly turned over. The observed activity in human cell lysates can be assigned to a single enzyme, namely, the human diadenosine tetraphosphate hydrolase NudT2. Since NudT2 has been shown to be a prognostic factor for breast cancer, the adenosine tetraphosphate analog might contribute to a better understanding of its involvement in cancerogenesis and allow the straightforward screening for inhibitors. Studying hydrolysis of the analogs in intact cells, we found that electroporation is a suitable method to deliver nucleotide analogs into the cytoplasm and show that high FRET efficiencies can be detected directly after internalization. Time-dependent experiments reveal that adenosine triphosphate and tetraphosphate analogs are both processed in the cellular environment. This study demonstrates that these nucleotide analogs indeed bear the potential to be powerful tools for the exploration of nucleotide turnover in the context of whole cells. PMID:26274552

  7. Life time test in direct borohydride fuel cell system

    Energy Technology Data Exchange (ETDEWEB)

    Jamard, Romain [Commissariat a l' Energie Atomique (CEA), LITEN-DTNM-LCH, 17 av. des martyrs, 38054 Grenoble Cedex 9 (France); Centre National de la Recherche Scientifique (CNRS), Laboratoire de Catalyse en Chimie Organique LACCO UMR6503, 40 av. du Recteur Pineau, 86022 Poitiers (France); Salomon, Jeremie; Martinent-Beaumont, Audrey [Commissariat a l' Energie Atomique (CEA), LITEN-DTNM-LCH, 17 av. des martyrs, 38054 Grenoble Cedex 9 (France); Coutanceau, Christophe [Centre National de la Recherche Scientifique (CNRS), Laboratoire de Catalyse en Chimie Organique LACCO UMR6503, 40 av. du Recteur Pineau, 86022 Poitiers (France)

    2009-09-05

    The electric performances of direct borohydride fuel cells (DBFCs) are evaluated in terms of power density and life time with respect to the NaBH{sub 4} concentration. A DBFC constituted of an anionic membrane, a 0.6 mg{sub Pt} cm{sup -2} anode and a commercial non-platinum based cathode led to performances as high as 200 mW cm{sup -2} at room temperature and with natural convection of air. Electrochemical life time test at 0.55 mA cm{sup -2} with a 5 M NaBH{sub 4}/1 M NaOH solution shows a voltage diminution of 1 mV h{sup -1} and a drastic drop of performances after 250 h. The life time is twice longer with 2 M NaBH{sub 4}/1 M NaOH solution (450 h) and the voltage decrease is 0.5 mV h{sup -1}. Analyses of the components after life time tests indicate that voltage loss is mainly due to the degradation of the cathode performance. Crystallisation of carbonate and borate is observed at the cathode side, although the anionic membrane displays low permeability to borohydride. (author)

  8. Modified SPEEK membranes for direct ethanol fuel cell

    KAUST Repository

    Maab, Husnul

    2010-07-01

    Membranes with low ethanol crossover were prepared aiming their application for direct ethanol fuel cell (DEFC). They were based on (1) sulfonated poly(ether ether ketone) (SPEEK) coated with carbon molecular sieves (CMS) and (2) on SPEEK/PI homogeneous blends. The membranes were characterized concerning their water and ethanol solution uptake, water and ethanol permeability in pervaporation experiments and their performance in DEFC tests. The ethanol permeabilities for the CMS-coated (180 nm and 400 nm thick layers) SPEEK were 8.5 and 3.1 x 10(-10) kg m s(-1) m(-2) and for the homogeneous SPEEK/PI blends membranes with 10, 20 and 30 wt.% of PI were 4.4, 1.0 and 0.4 x 10(-10) kg m s(-1) m(-2) respectively, which is 2- to 50-fold lower than that for plain SPEEK (19 x 10(-10) kg m s(-1) m(-2)). Particularly the SPEEK/PI membranes had substantially better performance than Nafion 117 membranes in DEFC tests at 60 degrees C and 90 degrees C. (C) 2010 Elsevier B.V. All rights reserved.

  9. New bimetallic EMF cell shows promise in direct energy conversion

    Science.gov (United States)

    Hesson, J. C.; Shimotake, H.

    1968-01-01

    Concentration cell, based upon a thermally regenerative cell principle, produces electrical energy from any large heat source. This experimental bimetallic EMF cell uses a sodium-bismuth alloy cathode and a pure liquid sodium anode. The cell exhibits reliability, corrosion resistance, and high current density performance.

  10. Optimum Performance of Direct Hydrogen Hybrid Fuel Cell Vehicles

    OpenAIRE

    Zhao, Hengbing; Burke, Andy

    2009-01-01

    Proton Exchange Membrane fuel cell (PEMFC) technology is one of the most attractive candidates for transportation applications due to its inherently high efficiency and high power density. However, the fuel cell system efficiency can suffer because of the need for forced air supply and water-cooling systems. Hence the operating strategy of the fuel cell system can have a significant impact on the fuel cell system efficiency and thus vehicle fuel economy. The key issues are how the fuel cell b...

  11. Direct reprogramming of Sertoli cells into multipotent neural stem cells by defined factors

    Institute of Scientific and Technical Information of China (English)

    Chao Sheng; Ziwei Wang; Changlong Guo; Hua-Jun Wu; Zhonghua Liu; Liu Wang; Shigang He; Xiu-Jie Wang; Zhiguo Chen; Qi Zhou; Qinyuan Zheng; Jianyu Wu; Zhen Xu; Libin Wang; Wei Li; Haijiang Zhang; Xiao-YangZhao; Lei Liu

    2012-01-01

    Multipotent neural stem/progenitor cells hold great promise for cell therapy.The reprogramming of fibroblasts to induced pluripotent stem cells as well as mature neurons suggests a possibility to convert a terminally differentiated somatic cell into a muitipotent state without first establishing pluripotency.Here,we demonstrate that sertoli cells derived from mesoderm can be directly converted into a multipotent state that possesses neural stem/progenitor cell properties.The induced neural stem/progenitor cells (iNSCs) express multiple NSC-specific markers,exhibit a global gene-expression profile similar to normal NSCs,and are capable of self-renewal and differentiating into glia and electrophysiologically functional neurons,iNSC-derived neurons stain positive for tyrosine hydroxylase (TH),γ-aminobutyric acid,and choline acetyltransferase.In addition,iNSCs can survive and generate synapses following transplantation into the dentate gyrus.Generation of iNSCs may have important implications for disease modeling and regenerative medicine.

  12. A dedicated circuit links direction-selective retinal ganglion cells to the primary visual cortex

    Science.gov (United States)

    Cruz-Martín, Alberto; El-Danaf, Rana N.; Osakada, Fumitaka; Sriram, Balaji; Dhande, Onkar S.; Nguyen, Phong L.; Callaway, Edward M.; Ghosh, Anirvan; Huberman, Andrew D.

    2014-03-01

    How specific features in the environment are represented within the brain is an important unanswered question in neuroscience. A subset of retinal neurons, called direction-selective ganglion cells (DSGCs), are specialized for detecting motion along specific axes of the visual field. Despite extensive study of the retinal circuitry that endows DSGCs with their unique tuning properties, their downstream circuitry in the brain and thus their contribution to visual processing has remained unclear. In mice, several different types of DSGCs connect to the dorsal lateral geniculate nucleus (dLGN), the visual thalamic structure that harbours cortical relay neurons. Whether direction-selective information computed at the level of the retina is routed to cortical circuits and integrated with other visual channels, however, is unknown. Here we show that there is a di-synaptic circuit linking DSGCs with the superficial layers of the primary visual cortex (V1) by using viral trans-synaptic circuit mapping and functional imaging of visually driven calcium signals in thalamocortical axons. This circuit pools information from several types of DSGCs, converges in a specialized subdivision of the dLGN, and delivers direction-tuned and orientation-tuned signals to superficial V1. Notably, this circuit is anatomically segregated from the retino-geniculo-cortical pathway carrying non-direction-tuned visual information to deeper layers of V1, such as layer 4. Thus, the mouse harbours several functionally specialized, parallel retino-geniculo-cortical pathways, one of which originates with retinal DSGCs and delivers direction- and orientation-tuned information specifically to the superficial layers of the primary visual cortex. These data provide evidence that direction and orientation selectivity of some V1 neurons may be influenced by the activation of DSGCs.

  13. Persistent directional cell migration requires ion transport proteins as direction sensors and membrane potential differences in order to maintain directedness

    Directory of Open Access Journals (Sweden)

    Sharma Priyanka

    2011-01-01

    Full Text Available Abstract Background Ion transport proteins generate small electric fields that can induce directional cell motility; however, little is known about their mechanisms that lead to directedness. We investigated Na, K-ATPase (NaKA and Na+/H+ exchanger isoforms (NHE1 and 3 in SaOS-2 and Calvarial osteoblasts, which present anode- and cathode- directed motility, during electrotaxis. Results Significant colocalizations of NaKA with vinculin and pNHE3 with ß-actin were observed to occur at the leading edges of cells. The directedness were attenuated when NaKA or NHE3 was inhibited, confirming their implication in directional sensing. Depending on the perceived direction, a divergent regulation in PIP2 levels as a function of NHE3 and NaKA levels was observed, suggesting that PIP2 may act as a spatiotemporal regulator of the cell membrane during electrotaxis. Moreover, at the same places where pNHE3 accumulates, bubble-shaped H+ clouds were observed, suggesting a physio-mechanical role for NHE3. The cell membrane becomes hyperpolarized at the front and depolarized at the back, which confirms NaKA activity at the leading edge. Conclusion We suggest a novel role for both NaKA and NHE3 that extends beyond ion translocation and conclude that they can act as directional sensors and Vmem as a regulatory cue which maintain the persistent direction in electrotaxis.

  14. Direct targeting of cancer cells: a multiparameter approach.

    Science.gov (United States)

    Heinrich, Eileen L; Welty, Lily Anne Y; Banner, Lisa R; Oppenheimer, Steven B

    2005-01-01

    Lectins have been widely used in cell surface studies and in the development of potential anticancer drugs. Many past studies that have examined lectin toxicity have only evaluated the effects on cancer cells, not their non-cancer counterparts. In addition, few past studies have evaluated the relationship between lectin-cell binding and lectin toxicity on both cell types. Here we examine these parameters in one study: lectin-cell binding and lectin toxicity with both cancer cells and their normal counterparts. We found that the human colon cancer cell line CCL-220/Colo320DM bound to agarose beads derivatized with Phaseolus vulgaris agglutinin (PHA-L) and wheat germ agglutinin (WGA), while the non-cancer human colon cell line CRL-1459/CCD-18Co did not. When these lectins were tested for their effects on cell viability in culture, both cell lines were affected by the lectins but at 6, 48 and 72 h incubation times, PHA-L was most toxic to the cancer cell line in a concentration dependent manner. At 48 h incubation, WGA was more toxic to the cancer cell line. The results suggest that it may be possible to develop lectin protocols that selectively target cancer cells for death. In any case, examination of both malignant cells and their non-malignant counterparts, analysis of their binding characteristics to immobilized lectins, and examination of the toxicity of free lectins in culture, provides a multiparameter model for obtaining more comprehensive information than from more limited approaches. PMID:16181664

  15. Clonogenic growth of human breast cancer cells co-cultured in direct contact with serum-activated fibroblasts

    International Nuclear Information System (INIS)

    Accumulating evidence suggests that fibroblasts play a pivotal role in promoting the growth of breast cancer cells. The objective of the present study was to characterize and validate an in vitro model of the interaction between small numbers of human breast cancer cells and human fibroblasts. We measured the clonogenic growth of small numbers of human breast cancer cells co-cultured in direct contact with serum-activated, normal human fibroblasts. Using DNA microarrays, we also characterized the gene expression profile of the serum-activated fibroblasts. In order to validate the in vivo relevance of our experiments, we then analyzed clinical samples of metastatic breast cancer for the presence of myofibroblasts expressing α-smooth muscle actin. Clonogenic growth of human breast cancer cells obtained directly from in situ and invasive tumors was dramatically and consistently enhanced when the tumor cells were co-cultured in direct contact with serum-activated fibroblasts. This effect was abolished when the cells were co-cultured in transwells separated by permeable inserts. The fibroblasts in our experimental model exhibited a gene expression signature characteristic of 'serum response' (i.e. myofibroblasts). Immunostaining of human samples of metastatic breast cancer tissue confirmed that myofibroblasts are in direct contact with breast cancer cells. Serum-activated fibroblasts promote the clonogenic growth of human breast cancer cells in vitro through a mechanism that involves direct physical contact between the cells. This model shares many important molecular and phenotypic similarities with the fibroblasts that are naturally found in breast cancers

  16. Attentional shifts by gaze direction in voluntary orienting: evidence from a microsaccade study

    OpenAIRE

    Yokoyama, Takemasa; Noguchi, Yasuki; Kita, Shinichi

    2012-01-01

    Shifts in spatial attention can be induced by the gaze direction of another. However, it is unclear whether gaze direction influences the allocation of attention by reflexive or voluntary orienting. The present study was designed to examine which type of attentional orienting is elicited by gaze direction. We conducted two experiments to answer this question. In Experiment 1, we used a modified Posner paradigm with gaze cues and measured microsaccades to index the allocation of attention. We ...

  17. Evidence for a directional dependence of Bose-Einstein correlations at the CERN intersecting storage rings

    International Nuclear Information System (INIS)

    In pp and panti p collisions at the CERN Intersecting Storage Rings, a directional dependence of the size of the pion-emitting region is observed using Bose-Einstein interference between identical charged pions. The data reveal a substantially larger dimension in the direction parallel to the beam axis than in the transverse direction, indicating a prolate shape of the emission region. For αα interactions, the data are consistent with a spherical shape. (orig.)

  18. Immunocytochemical Evidence that Monkey Rod Bipolar Cells Use GABA

    OpenAIRE

    Lassová, Luisa; Fina, Marie; Sulaiman, Pyroja; Vard, Noga

    2010-01-01

    Certain bipolar cells in most species immunostain for GABA or its synthesizing enzyme, GAD. However it is unknown whether they actually release GABA, and if so, from which cellular compartment, and by what release mechanism. We investigated these questions in monkey retina where rod bipolar cells immunostain for GABA. We found that rod bipolar cells immunostain for one isoform of GAD, GAD65, in their somas, dendrites, and axon terminals. Near the fovea, the somatic stain of rod bipolar cells ...

  19. NK cell biology: An update and future directions

    OpenAIRE

    Campbell, Kerry S.; Hasegawa, Jun

    2013-01-01

    Natural killer (NK) cells constitute a minor subset of normal lymphocytes that initiate innate immune responses toward tumor and virus-infected cells. They can mediate spontaneous cytotoxicity toward these abnormal cells and rapidly secrete numerous cytokines and chemokines to promote subsequent adaptive immune responses. Significant progress has been made in the past two decades to improve our understanding of NK cell biology. Here we review recent discoveries, including a better comprehensi...

  20. Are Consumer-Directed Home Care Beneficiaries Satisfied? Evidence from Washington State

    Science.gov (United States)

    Wiener, Joshua M.; Anderson, Wayne L.; Khatutsky, Galina

    2007-01-01

    Purpose: This study analyzed the effect of consumer-directed versus agency-directed home care on satisfaction with paid personal assistance services among Medicaid beneficiaries in Washington State. Design and Methods: The study analyzed a survey of 513 Medicaid beneficiaries receiving home- and community-based services. As part of a larger study,…

  1. Neutralizing antibodies are unable to inhibit direct viral cell-to-cell spread of human cytomegalovirus.

    Science.gov (United States)

    Jacob, Christian L; Lamorte, Louie; Sepulveda, Eliud; Lorenz, Ivo C; Gauthier, Annick; Franti, Michael

    2013-09-01

    Infection with human cytomegalovirus (CMV) during pregnancy is the most common cause of congenital disorders, and can lead to severe life-long disabilities with associated high cost of care. Since there is no vaccine or effective treatment, current efforts are focused on identifying potent neutralizing antibodies. A panel of CMV monoclonal antibodies identified from patent applications, was synthesized and expressed in order to reproduce data from the literature showing that anti-glycoprotein B antibodies neutralized virus entry into all cell types and that anti-pentameric complex antibodies are highly potent in preventing virus entry into epithelial cells. It had not been established whether antibodies could prevent subsequent rounds of infection that are mediated primarily by direct cell-to-cell transmission. A thorough validation of a plaque reduction assay to monitor cell-to-cell spread led to the conclusion that neutralizing antibodies do not significantly inhibit plaque formation or reduce plaque size when they are added post-infection. PMID:23849792

  2. Stratification of alpha ganglion cells and ON/OFF directionally selective ganglion cells in the rabbit retina

    OpenAIRE

    Zhang, Jian; Li, Wei; HOSHI, HIDEO; Mills, Stephen L.; MASSEY, STEPHEN C.

    2005-01-01

    The correlation between cholinergic sensitivity and the level of stratification for ganglion cells was examined in the rabbit retina. As examples, we have used ON or OFF α ganglion cells and ON/OFF directionally selective (DS) ganglion cells. Nicotine, a cholinergic agonist, depolarized ON/OFF DS ganglion cells and greatly enhanced their firing rates but it had modest excitatory effects on ON or OFF α ganglion cells. As previously reported, we conclude that DS ganglion cells are the most sens...

  3. CORRUPTION AND FOREIGN DIRECT INVESTMENT. EVIDENCE FROM CENTRAL AND EASTERN EUROPEAN STATES

    Directory of Open Access Journals (Sweden)

    Cristina Mihaela Amarandei

    2013-09-01

    Full Text Available This paper examines the impact of corruption on foreign direct investment inflows for ten Central and Eastern European states. The paper attempts to answer the question: what is the role of corruption in attracting foreign direct investments? Using the data from UNCTAD for foreign direct investment and Corruption Perception Index from Transparency International, for a period of 12 years, 2000-2012, we evaluate the specific impact of corruptions on FDI using GDP as control variable. Our results confirm the majority of literature and show a negative significant relation between the variables analyzed, but at a lower intensity than expected.

  4. Burnout and Risk of Cardiovascular Disease: Evidence, Possible Causal Paths, and Promising Research Directions

    Science.gov (United States)

    Melamed, Samuel; Shirom, Arie; Toker, Sharon; Berliner, Shlomo; Shapira, Itzhak

    2006-01-01

    Burnout is characterized by emotional exhaustion, physical fatigue, and cognitive weariness, resulting from prolonged exposure to work-related stress. The authors review the accumulated evidence suggesting that burnout and the related concept of vital exhaustion are associated with increased risk of cardiovascular disease and…

  5. Management of Child and Adolescent Eating Disorders: The Current Evidence Base and Future Directions

    Science.gov (United States)

    Gowers, Simon; Bryant-Waugh, Rachel

    2004-01-01

    Although eating disorders in children and adolescents remain a serious cause of morbidity and mortality, the evidence base for effective interventions is surprisingly weak. The adult literature is growing steadily, but this is mainly with regard to psychological therapies for bulimia nervosa and to some extent in the field of pharmacotherapy. This…

  6. BARRIERS TO COMMERCIALIZATION OF PASSIVE DIRECT METHANOL FUEL CELLS: A REVEIW

    OpenAIRE

    N. K. Shrivastava; S. B. THOMBRE

    2011-01-01

    Fuel cells are electro-chemical reactors which realize the direct conversion of the chemical energy of reactants to electrical energy, with high efficiency and high environmental compatibility. This article is concerned with one of the most advance fuel cells- direct methanol fuel cells (DMFCs). We present a comprehensive review on the commercialization barriers of passive DMFCs. The paper also summarizes past research efforts and possible future directions towards these problems.

  7. Direct evidence for wake-related increases and sleep-related decreases in synaptic strength in rodent cortex

    OpenAIRE

    Liu, Zhong-Wu; Faraguna, Ugo; Cirelli, Chiara; Tononi, Giulio; Gao, Xiao-Bing

    2010-01-01

    Despite evidence that waking is associated with net synaptic potentiation and sleep with depression, direct proof for changes in synaptic currents is lacking in large brain areas such as the cerebral cortex. By recording miniature excitatory postsynaptic currents (mEPSCs) from frontal cortex slices of mice and rats that had been awake or asleep, we found that the frequency and amplitude of mEPSCs increased after wake and decreased after sleep. Recovery sleep after sleep deprivation also decre...

  8. A comparison of policy and direct practice stakeholder perceptions of factors affecting evidence-based practice implementation using concept mapping

    OpenAIRE

    Green Amy E; Aarons Gregory A

    2011-01-01

    Abstract Background The goal of this study was to assess potential differences between administrators/policymakers and those involved in direct practice regarding factors believed to be barriers or facilitating factors to evidence-based practice (EBP) implementation in a large public mental health service system in the United States. Methods Participants included mental health system county officials, agency directors, program managers, clinical staff, administrative staff, and consumers. As ...

  9. A comparison of policy and direct practice stakeholder perceptions of factors impacting evidence-based practice implementation using concept mapping

    OpenAIRE

    Green, Amy E.; Aarons, Gregory A.

    2011-01-01

    Abstract Background The goal of this study was to assess potential differences between administrators/policymakers and those involved in direct practice regarding factors believed to be barriers or facilitating factors to evidence-based practice (EBP) implementation in a large public mental health service system in the United States. Methods Participants included mental health system county officials, agency directors, program managers, clinical staff, administrative staff...

  10. EVIDENCE ON TWO-WAY RELATIONSHIPS BETWEEN FOREIGN DIRECT INVESTMENT INFLOWS AND COUNTRY-LEVEL INDIVIDUAL GOVERNANCE INDICATORS

    OpenAIRE

    OMAR AL FAROOQUE; SUBBA REDDY YARRAM

    2013-01-01

    This paper investigates the interactions between foreign direct investment (FDI) and country-level individual governance indicators for a sample of 173 countries from 1996 to 2007, and also the effect of legal origin, international financial reporting standards (IFRS) and ownership diffusion on them. We find evidence of positively significant two-way relationships between each of the six individual governance indicators and lagged FDI inflows scaled by lagged GDP to confirm that governance is...

  11. Cutaneous postirradiation sarcoma. Ultrastructural evidence of pluripotential mesenchymal cell derivation

    International Nuclear Information System (INIS)

    A 75-year-old man developed synchronous multicentric cutaneous sarcomas and basal cell carcinoma of the face 57 years after receiving irradiation for acne. During the previous 30 years he had been treated many times for actinic keratoses and basal cell carcinomas. Surgical treatment had included total nasectomy, excision, and replacement of the skin of the upper and lower lips and the chin. Due to the multiplicity of morphologic patterns, it was difficult to subtype the sarcomas. Ultrastructural studies showed histiocyte-like, fibroblast-like and vasoformative cells suggesting an origin from a pluripotential mesenchymal stem cells

  12. Foreign Direct Investment and Electronics Exports: Exploratory Empirical Evidence from Malaysia's Top Five Electronics Exports

    OpenAIRE

    Tuck Cheong Tang; Koi Nyen Wong

    2007-01-01

    The foreign direct investment (FDI) has contributed significantly to Malaysia's electronics exports as well as the growth and development of the electronics industry as a result of the export-oriented industrialization initiatives undertaken since 1970s. The aim of this study is to explore the causation between FDI and electronics exports by using Malaysia''s top five electronics exports by SITC (Standard International Trade Classification) product groups. The findings show a bi-directional c...

  13. Direct and indirect forms of non-suicidal self-injury: Evidence for a distinction

    OpenAIRE

    St. Germain, Sarah Ann; Hooley, Jill Miranda

    2012-01-01

    Non-suicidal self-injury (NSSI) involves deliberate acts (such as cutting) that directly damage the body but occur without suicidal intent. However, other non-suicidal behaviors that involve people mistreating or abusing themselves but that do not deliberately and directly damage bodily tissue may have much in common with NSSI. Such ‘indirect’ methods of self-injury might include involvement in abusive relationships, substance abuse, risky or reckless behavior, or eating disordered behavior. ...

  14. Effects of Physician-Directed Pharmaceutical Promotion on Prescription Behaviors: Longitudinal Evidence

    OpenAIRE

    Anusua Datta; Dhaval M. Dave

    2013-01-01

    Spending on prescription drugs (Rx) represents one of the fastest growing components of U.S. healthcare spending, and has coincided with an expansion of pharmaceutical promotional spending. Most (83%) of Rx promotion is directed at physicians in the form of visits by pharmaceutical representatives (known as detailing) and drug samples provided to physicians' offices. Such promotion has come under increased public scrutiny, with critics contending that physician-directed promotion may play a r...

  15. Directional cell migration, but not proliferation, drives hair placode morphogenesis.

    Science.gov (United States)

    Ahtiainen, Laura; Lefebvre, Sylvie; Lindfors, Päivi H; Renvoisé, Elodie; Shirokova, Vera; Vartiainen, Maria K; Thesleff, Irma; Mikkola, Marja L

    2014-03-10

    Epithelial reorganization involves coordinated changes in cell shapes and movements. This restructuring occurs during formation of placodes, ectodermal thickenings that initiate the morphogenesis of epithelial organs including hair, mammary gland, and tooth. Signaling pathways in ectodermal placode formation are well known, but the cellular mechanisms have remained ill defined. We established imaging methodology for live visualization of embryonic skin explants during the first wave of hair placode formation. We found that the vast majority of placodal cells were nonproliferative throughout morphogenesis. We show that cell compaction and centripetal migration are the main cellular mechanisms associated with hair placode morphogenesis and that inhibition of actin remodeling suppresses placode formation. Stimulation of both ectodysplasin/NF-κB and Wnt/β-catenin signaling increased cell motility and the number of cells committed to placodal fate. Thus, cell fate choices and morphogenetic events are controlled by the same molecular pathways, providing the framework for coordination of these two processes. PMID:24636260

  16. Amorphous silicon materials and solar cells - Progress and directions

    Science.gov (United States)

    Sabisky, E.; Mahan, H.; McMahon, T.

    In 1978, the U.S. Department of Energy initiated government sponsored research in amorphous materials and thin film solar cells. The program was subsequently transferred to the Solar Energy Research Institute for program management. The program grew into a major program for the development of high efficiency (greater than 10 percent), cost effective (15-40 cents per peak watt) thin film amorphous solar cells. The present international interest, the substantial progress made in the device area (2 percent PIN cell in 1976 to 10 percent PIN cell in 1982), and the marketing of the first consumer products using thin film solar cells are to a large ducts using thin film solar cells are to a large extent a consequence of this goal-oriented program.

  17. Quantifying the weight of fingerprint evidence through the spatial relationship, directions and types of minutiae observed on fingermarks.

    Science.gov (United States)

    Neumann, Cedric; Champod, Christophe; Yoo, Mina; Genessay, Thibault; Langenburg, Glenn

    2015-03-01

    This paper presents a statistical model for the quantification of the weight of fingerprint evidence. Contrarily to previous models (generative and score-based models), our model proposes to estimate the probability distributions of spatial relationships, directions and types of minutiae observed on fingerprints for any given fingermark. Our model is relying on an AFIS algorithm provided by 3M Cogent and on a dataset of more than 4,000,000 fingerprints to represent a sample from a relevant population of potential sources. The performance of our model was tested using several hundreds of minutiae configurations observed on a set of 565 fingermarks. In particular, the effects of various sub-populations of fingers (i.e., finger number, finger general pattern) on the expected evidential value of our test configurations were investigated. The performance of our model indicates that the spatial relationship between minutiae carries more evidential weight than their type or direction. Our results also indicate that the AFIS component of our model directly enables us to assign weight to fingerprint evidence without the need for the additional layer of complex statistical modeling involved by the estimation of the probability distributions of fingerprint features. In fact, it seems that the AFIS component is more sensitive to the sub-population effects than the other components of the model. Overall, the data generated during this research project contributes to support the idea that fingerprint evidence is a valuable forensic tool for the identification of individuals. PMID:25637956

  18. PD-1 as an emerging therapeutic target in renal cell carcinoma: current evidence

    Directory of Open Access Journals (Sweden)

    Tykodi SS

    2014-07-01

    Full Text Available Scott S Tykodi Department of Medicine, Division of Medical Oncology, University of Washington, Seattle, WA, USA Abstract: Renal cell carcinoma (RCC is the most common primary malignant tumor of the kidney in adults, representing approximately 4% of all adult cancers in the United States. Metastatic RCC is poorly responsive to conventional cytotoxic chemotherapies but can be sensitive to T-cell-directed immunotherapies such as interferon-α or interleukin-2. Despite recent progress in the application of antiangiogenic “targeted therapies” for metastatic RCC, high-dose interleukin-2 remains an appropriate first-line therapy for select patients and is associated with durable complete remissions in a small fraction of treated patients. Thus, advanced RCC provides a unique opportunity to investigate the requirements for effective antitumor immunotherapy. Accumulating evidence suggests that resistance mechanisms exploited by RCC and other tumor types may play a dominant role in limiting the effectiveness of tumor-reactive adaptive immune responses. Expression of the inhibitory coreceptor programmed cell death-1 (PD-1 on tumor-infiltrating lymphocytes within RCC tumors, as well as the expression of the PD-1 ligand (PD-L1 on RCC tumor cells, are strong negative prognostic markers for disease-specific death in RCC patients. Monoclonal antibodies targeting either PD-1 or PD-L1 have now entered clinic trials and have demonstrated promising antitumor effects for refractory metastatic RCC. This review summarizes the results of published and reported studies of PD-1- and PD-L1-targeted therapies enrolling patients with advanced RCC, focusing on key safety, toxicity, and efficacy end points. Prospects for advanced phase clinical testing and novel therapy combinations with PD-1- and PD-L1-targeted agents are discussed. Keywords: renal cell carcinoma, immune checkpoint, immunotherapy, T-lymphocyte, PD-1, PD-L1

  19. Glioma-associated endothelial cells show evidence of replicative senescence

    International Nuclear Information System (INIS)

    The innately programmed process of replicative senescence has been studied extensively with respect to cancer, but primarily from the perspective of tumor cells overcoming this stringent innate barrier and acquiring the capacity for unlimited proliferation. In this study, we focus on the potential role of replicative senescence affecting the non-transformed endothelial cells of the blood vessels within the tumor microenvironment. Based on the well-documented aberrant structural and functional features of blood vessels within solid tumors, we hypothesized that tumor-derived factors may lead to premature replicative senescence in tumor-associated brain endothelial cells (TuBEC). We show here that glioma tissue, but not normal brain tissue, contains cells that express the signature of replicative senescence, senescence-associated β-galactosidase (SA-β-gal), on CD31-positive endothelial cells. Primary cultures of human TuBEC stain for SA-β-gal and exhibit characteristics of replicative senescence, including increased levels of the cell cycle inhibitors p21 and p27, increased resistance to cytotoxic drugs, increased growth factor production, and inability to proliferate. These data provide the first demonstration that tumor-derived brain endothelial cells may have reached an end-stage of differentiation known as replicative senescence and underscore the need for anti-angiogenic therapies to target this unique tumor-associated endothelial cell population

  20. Evidence for an androgen receptor in porcine Leydig cells

    International Nuclear Information System (INIS)

    Cytosol and nuclear androgen receptor concentrations were measured in freshly prepared and cultured Leydig cells of immature pig testis with exchange assays using (3H)methyltrienolone as labelled ligand. Androgen receptors in Leydig cells had high affinity for (3H)methyltrienolone and sterios binding specificity typical of an androgen receptor. The mean receptor concentrations were 76 fmol/mg protein and 210 fmol/mg DNA for cytosol and nuclei, respectively. In sucrose gradients, cytosol androgen receptors sedimented in the 4 S region. The cells maintained androgen receptors under culture conditions. Exposure of cultured cells to (3H)methyltrienolone (10 nmol/l) resulted in accumulation of androgen receptors in the nuclei with maximal uptake by 1 h. We conclude that methyltrienolone binding sites with characteristics of androgen receptors were idenfified in both cytosol and nuclei of porcine Leydig cells. (author)

  1. Performance of miniaturized direct methanol fuel cell (DMFC) devices using micropump for fuel delivery

    Science.gov (United States)

    Zhang, Tao; Wang, Qing-Ming

    A fuel cell is a device that can convert chemical energy into electricity directly. Among various types of fuel cells, both polymer electrolyte membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs) can work at low temperature (mini pumps, the size of the piezoelectric micropump is much smaller and the energy consumption is much lower. Thus, it is very viable and effective to use a piezoelectric valveless micropump for fuel delivery in miniaturized DMFC power systems.

  2. The Law of Aggregate Demand : Empirical Evidence From India Using Nonparametric Direct Average Derivative Estimation procedure

    OpenAIRE

    Chakrabarty, Manisha

    2001-01-01

    This paper attempts to provide empirical evidence of the positive definiteness of the mean income effect matrix, a sufficient condition for market demand to satisfy the {\\it law of demand} derived by H\\"{a}rdle, Hildenbrand and Jerison [HHJ(1991)]. Increasing heterogeneity in spending of populations of households leads to this sufficient condition which is falsifiable from cross-section data. Based on this framework we use the National Sample Survey (NSS) 50-th round data (1993-1994) for the ...

  3. Direct evidence of spin-split one-dimensional metallic surface state on Si(557)-Au

    OpenAIRE

    Okuda, Taichi; Miyamoto, Koji; Takeichi, Yasuo; Miyahara, Hirokazu; Ogawa, Manami; Harasawa, Ayumi; Kimura, Akio; Matsuda, Iwao; Kakizaki, Akito; Shishidou, Tatsuya; Oguchi, Tamio

    2010-01-01

    We report unprecedented evidence of a spin split one-dimensional metallic surface state for the system of Si(557)-Au obtained by means of high-resolution spin- and angle-resolved photoelectron spectroscopy combined with first principles calculations. The surface state shows double parabolic energy dispersions along the Au chain structure together with a reversal of the spin polarization with respect to the time-reversal symmetry point as is characteristic from the Rashba effect. Moreover, we ...

  4. Foreign Direct Investment and Pollution Havens: Evaluating the Evidence from China

    OpenAIRE

    Dean, Judith M.; Lovely, Mary E.; Wang, Hua

    2004-01-01

    One of the most contentious debates today is whether pollution-intensive industries seek locations with weak environmental standards, turning these locations into 'pollution havens." Empirical studies to date show little evidence to support the pollution haven hypothesis, but suffer potentially from omitted variable bias, specification, and measurement errors. This paper estimates the strength of pollution-haven behavior by examining the location choices of equity joint venture (EJV) projects...

  5. Direct sorbitol proton exchange membrane fuel cell using moderate catalyst loadings

    International Nuclear Information System (INIS)

    Highlights: •The performance of a direct sorbitol fuel cell was evaluated at different temperatures. •The performance was compared to the performance of a direct glucose fuel cell. •The mass specific peak power density of the direct sorbitol fuel cell was 3.6 mW mg−1totalcatalystloading at 80 °C. •Both sorbitol and glucose fuel cell suffer from deactivation. -- Abstract: Recent progress in biomass hydrolysis has made it interesting to study the use of sorbitol for electricity generation. In this study, sorbitol and glucose are used as fuels in proton exchange membrane fuel cells having 0.9 mg cm−2 PtRu/C at the anode and 0.3 mg cm−2 Pt/C at the cathode. The sorbitol oxidation was found to have slower kinetics than glucose oxidation. However, at low temperatures the direct sorbitol fuel cell shows higher performance than the direct glucose fuel cell, attributed to a lower degree of catalyst poisoning. The performance of both fuel cells is considerably improved at higher temperatures. High temperatures lower the poisoning, allowing the direct glucose fuel cell to reach a higher performance than the direct sorbitol fuel cell. The mass specific peak power densities of the direct sorbitol and direct glucose fuel cells at 65 °C was 3.2 mW mg−1catalyst and 3.5 mW mg−1catalyst, respectively. Both of these values are one order of magnitude larger than mass specific peak power densities of earlier reported direct glucose fuel cells using proton exchange membranes. Furthermore, both the fuel cells showed a considerably decrease in performance with time, which is partially attributed to sorbitol and glucose crossover poisoning the Pt/C cathode

  6. Establishment of a pig fibroblast-derived cell line for locus-directed transgene expression in cell cultures and blastocysts

    DEFF Research Database (Denmark)

    Jakobsen, Jannik E; Li, Juan; Moldt, Brian;

    2011-01-01

    We report the establishment of a spontaneously immortalized pig cell line designated Pig Flip-in Visualize (PFV) for locus-directed transgene expression in pig cells and blastocysts. The PFV cell line was isolated from pig ear fibroblasts transfected with a Sleeping Beauty DNA transposon-based do......We report the establishment of a spontaneously immortalized pig cell line designated Pig Flip-in Visualize (PFV) for locus-directed transgene expression in pig cells and blastocysts. The PFV cell line was isolated from pig ear fibroblasts transfected with a Sleeping Beauty DNA transposon...

  7. Method of operating a direct dme fuel cell system

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to a method of operating a fuel cell system comprising one or more fuel cells with a proton exchange membrane, wherein the membrane is composed of a polymeric material comprising acid-doped polybenzimidazole (PBI). The method comprises adjusting the operating...

  8. Angular velocity and head direction signals recorded from the dorsal tegmental nucleus of gudden in the rat: implications for path integration in the head direction cell circuit.

    Science.gov (United States)

    Sharp, P E; Tinkelman, A; Cho, J

    2001-06-01

    When a rat navigates through space, head direction (HD) cells provide an ongoing signal of the rat's directional heading. It is thought that these cells rely, in part, on angular path integration of the rat's head movements. This integration requires that the HD cell system receive information about angular head movements and that this information be combined with the current directional signal, to generate the next "predicted" direction. Recent data suggest that the dorsal tegmental nucleus (DTN) may play a critical role in helping to generate the HD cell signal. To test this, recordings were made from cells in the DTN in freely moving rats. The following cell types were found: (a) "classic" HD cells, (b) angular velocity cells, and (c) cells that fired as a function of both head direction and angular velocity. Thus, DTN cells exhibit firing characteristics that are critical to the neural circuit hypothesized for generation of the HD cell signal. PMID:11439447

  9. Direct toxicity of nonsteroidal antiinflammatory drugs for renal medullary cells

    OpenAIRE

    Rocha, Gerson M.; Michea, Luis F.; Peters, Eugenia M.; Kirby, Martha; Xu, Yuhui; Ferguson, Douglas R.; Burg, Maurice B.

    2001-01-01

    Antipyretic analgesics, taken in large doses over a prolonged period, cause a specific form of kidney disease, characterized by papillary necrosis and interstitial scarring. Epidemiological evidence incriminated mixtures of drugs including aspirin (ASA), phenacetin, and caffeine. The mechanism of toxicity is unclear. We tested the effects of ASA, acetaminophen (APAF, the active metabolite of phenacetin), caffeine, and other related drugs individually and in combination...

  10. Personal development plans and self‐directed learning for healthcare professionals: are they evidence based?

    OpenAIRE

    Jennings, Stephen F

    2007-01-01

    The UK chief medical officer's recommendations for the re‐licensing and performance management of doctors will mean a move from a formative towards a summative role for appraisal and its adjunct, the personal development plan. Where does this leave medical educators trying to promote reflective learning? It is taken for granted that self‐directed learning is the sine qua non of all adult learning. But is it? This review re‐evaluates self‐directed learning and its corollary, the personal devel...

  11. Foreign Direct Investment Effect on Economic Growth: Evidence from Guinea Republic in West Africa

    OpenAIRE

    Keita Mohamed Lamine; Dakai Yang

    2010-01-01

    The aim of this paper is to understand the contribution of Foreign Direct Investment on Guinea Republic¡¯s Economic growth. The Granger Causality Test is used to study the relationship between FDI and Economic Growth proxies. Our results show that the level of FDI is still low in order to promote economic growth for the Guinea Republic. Indeed, the Granger Causality Test demonstrated that the GDP can promote the level of foreign direct investment, which means that if the level of GDP increase...

  12. Hysteresis in the perception of motion direction as evidence for neural cooperativity.

    Science.gov (United States)

    Williams, D; Phillips, G; Sekuler, R

    When elements of a parallel network, such as the human brain, are extensively interconnected, the network can exhibit 'cooperative behaviour'. Such behaviour, which is characterized by order-disorder transitions, multi-stable states, and a form of memory called 'hysteresis', has been observed in human stereopsis and has motivated models of stereopsis that incorporate cooperative networks. More recently, cooperative phenomena have also been observed in human visual motion perception. This report strongly supports a cooperative interpretation of motion perception by demonstrating hysteresis in the perception of motion direction. The results agree quantitatively with a mathematical model incorporating nonlinear excitatory and inhibitory interactions among direction-selective elements. PMID:3785395

  13. Direct Connect Supersonic Combustion Facility (Research Cell 22)

    Data.gov (United States)

    Federal Laboratory Consortium — Description: RC22 is a continuous-flow, direct-connect supersonic-combustion research facility that is capable of simulating flight conditions from Mach 3.0 to Mach...

  14. Cdc42 is not essential for filopodium formation, directed migration, cell polarization, and mitosis in fibroblastoid cells

    DEFF Research Database (Denmark)

    Czuchra, Aleksandra; Wu, Xunwei; Meyer, Hannelore;

    2005-01-01

    of Cdc42 did not affect filopodium or lamellipodium formation and had no significant influence on the speed of directed migration nor on mitosis. Cdc42-deficient cells displayed a more elongated cell shape and had a reduced area. Furthermore, directionality during migration and reorientation of the...

  15. Recent preclinical evidence advancing cell therapy for Alzheimer's disease

    OpenAIRE

    Borlongan, Cesar V.

    2012-01-01

    Alzheimer's disease (AD) causes brain degeneration, primarily depleting cholinergic cells, and leading to cognitive and learning dysfunction. Logically, to augment the cholinergic cell loss, a viable treatment for AD has been via drugs boosting brain acetylcholine production. However, this is not a curative measure. To this end, nerve growth factor (NGF) has been examined as a possible preventative treatment against cholinergic neuronal death while enhancing memory capabilities; however, NGF ...

  16. Carbon fuel particles used in direct carbon conversion fuel cells

    Science.gov (United States)

    Cooper, John F.; Cherepy, Nerine

    2012-10-09

    A system for preparing particulate carbon fuel and using the particulate carbon fuel in a fuel cell. Carbon particles are finely divided. The finely dividing carbon particles are introduced into the fuel cell. A gas containing oxygen is introduced into the fuel cell. The finely divided carbon particles are exposed to carbonate salts, or to molten NaOH or KOH or LiOH or mixtures of NaOH or KOH or LiOH, or to mixed hydroxides, or to alkali and alkaline earth nitrates.

  17. Anxiety and Reading Difficulties in Early Elementary School: Evidence for Unidirectional- or Bi-Directional Relations?

    Science.gov (United States)

    Grills-Taquechel, Amie E.; Fletcher, Jack M.; Vaughn, Sharon R.; Stuebing, Karla K.

    2012-01-01

    The present study examined competing models of the bi-directional influences of anxiety and reading achievement. Participants were 153 ethnically-diverse children (84 male, 69 female) from general education classes evaluated in the winter and spring of their first-grade academic year. Children completed standardized measures of reading achievement…

  18. Intentional Forgetting Reduces Color-Naming Interference: Evidence from Item-Method Directed Forgetting

    Science.gov (United States)

    Lee, Yuh-shiow; Lee, Huang-mou; Fawcett, Jonathan M.

    2013-01-01

    In an item-method-directed forgetting task, Chinese words were presented individually, each followed by an instruction to remember or forget. Colored probe items were presented following each memory instruction requiring a speeded color-naming response. Half of the probe items were novel and unrelated to the preceding study item, whereas the…

  19. Direct Evidence that RNA Inhibits APOBEC3G ssDNA Cytidine Deaminase Activity

    OpenAIRE

    McDougall, William M.; Smith, Harold C.

    2011-01-01

    APOBEC3G (A3G) is a deoxycytidine deaminase active on ssDNA substrates. In HIV infected cells A3G interacted with reverse transcription complexes where its activity as a deoxycytidine deaminase led to mutation of the viral genome. A3G not only bound ssDNA, but it also had an intrinsic ability to bind RNA. In many cell types that can support HIV replication, A3G ssDNA deaminase activity was suppressed and the enzyme resided in high molecular mass, ribonucleoprotein complexes associated with cy...

  20. Evidence that RpoS (sigmaS) in Borrelia burgdorferi is controlled directly by RpoN (sigma54/sigmaN).

    Science.gov (United States)

    Smith, Alexandra H; Blevins, Jon S; Bachlani, Gulnaz N; Yang, Xiaofeng F; Norgard, Michael V

    2007-03-01

    The alternative sigma factor (RpoN-RpoS) pathway controls the expression of key virulence factors in Borrelia burgdorferi. However, evidence to support whether RpoN controls rpoS directly or, perhaps, indirectly via a transactivator has been lacking. Herein we provide biochemical and genetic evidence that RpoN directly controls rpoS in B. burgdorferi. PMID:17158681

  1. Direct evidence for terrace bending from He beam scattering on Pt(997)

    International Nuclear Information System (INIS)

    He-nozzle beams were scattered on a stepped Pt(997) surface. Diffraction peaks up to the 6th order are clearly resolved. For incident angles 0, the diffraction patterns are very similar to the patterns obtained by light scattering on echelette gratings. An elementary model based upon this analogy fits the results fairly well. The deviations observed for glancing angles of incidence are interpreted as an evidence for an upward bending of the interaction potential on the terrace in the vicinity of the downward step. (Auth.)

  2. Isolation of additional monoclonal antibodies directed against cell surface antigens of Myxococcus xanthus cells undergoing submerged development.

    OpenAIRE

    Gill, J.S.; Dworkin, M

    1988-01-01

    Thirteen additional monoclonal antibodies directed against cell surface antigens of Myxococcus xanthus cells undergoing submerged development were isolated and partially characterized. As measured by quantitative enzyme-linked immunosorbent assay, 10 of these antibodies recognized antigens common to both vegetatively growing cells and cells undergoing submerged development; 3 antibodies recognized antigens specific to developing cells. Five antigens were revealed as single bands on Western bl...

  3. Oct4 shuffles Sox partners to direct cell fate

    OpenAIRE

    AlFatah Mansour, Abed; Hanna, Jacob H.

    2013-01-01

    Early cell fate decisions demand rapid rewiring of transcriptional circuits. Stanton and colleagues report on enhancer-dependent partnering of Oct4 with either Sox2 or Sox17 to switch from pluripotency to differentiation.

  4. High Efficiency Direct Methane Solid Oxide Fuel Cell System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has a defined need for energy dense and highly efficient energy storage and power delivery systems for future space missions. Compared to other fuel cell...

  5. A direct computer control concept for mammalian cell fermentation processes

    OpenAIRE

    Büntemeyer, Heino; Marzahl, Rainer; Lehmann, Jürgen

    1994-01-01

    In the last 10 years, new assignments and the special demands of mammalian cells to the culture conditions caused the development of complex small scale fermentation setups. The use of continuous fermentation and cell retention devices requires appropriate process control systems. An arrangement for control and data-acquisition of complex laboratory-scale bioreactors is presented. The fundamental idea was the usage of a standard personal computer, which is connected to pumps, valves and senso...

  6. Advantages of RGD peptides for directing cell association with biomaterials

    OpenAIRE

    Bellis, Susan L.

    2011-01-01

    Despite many years of in vitro research confirming the effectiveness of RGD in promoting cell attachment to a wide variety of biomaterials, animal studies evaluating tissue responses to implanted RGD-functionalized substrates have yielded more variable results The goals of this report are to present some of the reasons why cell culture studies may not always reliably predict in vivo responses, and more importantly, to highlight potential applications that may benefit from the use of RGD pepti...

  7. Compact bipolar plate-free direct methanol fuel cell stacks.

    Science.gov (United States)

    Dong, Xue; Takahashi, Motohiro; Nagao, Masahiro; Hibino, Takashi

    2011-05-14

    Fuel cells with a PtAu/C anode and a Pr-doped Mn(2)O(3)/C cathode were stacked without using a bipolar plate, and their discharge properties were investigated in a methanol aqueous solution bubbled with air. A three-cell stack exhibited a stack voltage of 2330 mV and a power output of 21 mW. PMID:21451850

  8. Functional living biointerfaces to direct cell-material interaction

    OpenAIRE

    Rodrigo Navarro, Aleixandre

    2015-01-01

    [EN] This thesis deals with the development of a living biointerface between synthetic substrates and living cells to engineer cell-material interactions for tissue engineering purposes. This living biointerface is made of Lactococcus lactis, a non-pathogenic lactic bacteria widely used as starter in the dairy industry and, recently, in the expression of heterologous proteins in applications such as oral vaccine delivery or membrane-bound expression of proteins. L. lactis has been engine...

  9. Enhanced micronucleus formation in the descendants of γ-ray-irradiated tobacco cells: Evidence for radiation-induced genomic instability in plant cells

    International Nuclear Information System (INIS)

    Ionizing radiation-induced genomic instability has been documented in various end points such as chromosomal aberrations and mutations, which arises in the descendants of irradiated mammalian or yeast cells many generations after the initial insult. This study aimed at addressing radiation-induced genomic instability in higher plant tobacco cells. We thus investigated micronucleus (MN) formation and cell proliferation in tobacco cells irradiated with γ-rays and their descendants. In γ-irradiated cells, cell cycle was arrested at G2/M phase at around 24 h post-irradiation but released afterward. In contrast, MN frequency peaked at 48 h post-irradiation. Almost half of 40 Gy-irradiated cells had MN at 48 h post-irradiation, but proliferated as actively as sham-irradiated cells up to 120 h post-irradiation. Moreover, the descendants that have undergone at least 22 generations after irradiation still showed a two-fold MN frequency compared to sham-irradiated cells. This is the direct evidence for radiation-induced genomic instability in tobacco cells.

  10. Epigenetics of Posttraumatic Stress Disorder: Current Evidence, Challenges, and Future Directions.

    Science.gov (United States)

    Zannas, Anthony S; Provençal, Nadine; Binder, Elisabeth B

    2015-09-01

    Posttraumatic stress disorder (PTSD) is a stress-related psychiatric disorder that is thought to emerge from complex interactions among traumatic events and multiple genetic factors. Epigenetic regulation lies at the heart of these interactions and mediates the lasting effects of the environment on gene regulation. An increasing body of evidence in human subjects with PTSD supports a role for epigenetic regulation of distinct genes and pathways in the pathogenesis of PTSD. The role of epigenetic regulation is further supported by studies examining fear conditioning in rodent models. Although this line of research offers an exciting outlook for future epigenetic research in PTSD, important limitations include the tissue specificity of epigenetic modifications, the phenomenologic definition of the disorder, and the challenge of translating molecular evidence across species. These limitations call for studies that combine data from postmortem human brain tissue and animal models, assess longitudinal epigenetic changes in living subjects, and examine dimensional phenotypes in addition to diagnoses. Moreover, examining the environmental, genetic, and epigenetic factors that promote resilience to trauma may lead to important advances in the field. PMID:25979620

  11. Mantle cell lymphoma cell lines show no evident immunoglobulin heavy chain stereotypy but frequent light chain stereotypy.

    Science.gov (United States)

    Pighi, Chiara; Barbi, Stefano; Bertolaso, Anna; Zamò, Alberto

    2013-08-01

    Mantle cell lymphoma shows a peculiar immunogenetic profile, but the functional consequences of this fact are unknown. We have determined the precise sequences of rearranged heavy and light chain genes in several mantle cell lymphoma cell lines and investigated the presence of heavy and light chain stereotypy. These cell lines use IGHV and IGLV genes that are known to be preferentially rearranged in mantle cell lymphoma, but we found no evidence of heavy chain stereotypy. In contrast, one cell line (Mino) showed a nearly identical light chain complementarity-determining region 3 when compared to the only published light chain cluster. Two cell line couples (Jeko-1/UPN-2 and JVM-2/JVM-13) showed a highly similar light chain that satisfied the criteria for stereotypy. Our data show that mantle cell lymphoma cell lines resemble the IGHV and IGLV usage of mantle cell lymphoma, and foster the hypothesis that light chain stereotypy might be under-recognized. PMID:23245212

  12. Raman scattering evidence of hydrohalite formation on frozen yeast cells

    CERN Document Server

    Okotrub, K A

    2012-01-01

    We studied yeast cells in physiological solution during freezing by Raman microspectroscopy technique. The purpose was to find out the origin of a sharp peak near ~3430 cm^-1 in Raman spectrum of frozen mammalian cells, observed earlier (J. Dong et al, Biophys. J., 99 (2010) 2453), which presumably could be used as an indicator of intracellar ice appearance. We have shown that this line (actually doublet of 3408 and 3425 cm^-1) corresponds to Raman spectrum of hydrohalite (NaCl-2H2O), which is formed as the result of the eutectic crystallization of the liquid solution around the cells. We also show that the spatial distribution of hydrohalite in the sample significantly depends on the cooling rate. At lower cooling rate (1{\\deg}C/min), products of eutectic crystallization form layer on the cell surface which thickness varies for different cells and can reach ~1 {\\mu}m in thickness. At higher cooling rate (20{\\deg}C/min), the hydrohalite distribution appears more homogeneous, in the sample, and the eutectic cr...

  13. Infrared spectroscopic evidence of a direct addition reaction between palygorskite and pyromellitic dianhydride

    International Nuclear Information System (INIS)

    Highlights: ► A direct addition reaction between palygorskite and pyromellitic dianhydride. ► The graft of anhydride to the bound water on the external surface of palygorskite. ► Application of palygorskite without organo-modification. - Abstract: Palygorskite covalently grafted with pyromellitic dianhydride was investigated. Untreated and grafted samples were characterized by X-ray diffraction, thermogravimetry, and Fourier transform infrared spectroscopy. Infrared results showed the direct grafting of anhydride onto the bound water molecules on the external surfaces of the palygorskite. The grafting modification makes palygorskite more readily compatible with anhydride, resulting in substantial enhancements in the glass transition temperature and flexural strength of the anhydride-cured epoxy resin/palygorskite nanocomposites.

  14. Infrared spectroscopic evidence of a direct addition reaction between palygorskite and pyromellitic dianhydride

    Energy Technology Data Exchange (ETDEWEB)

    Yan Wenchang [CAS Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); School of Civil Engineering, Anhui University of Architecture, Hefei 230022 (China); Yuan Peng, E-mail: yuanpeng@gig.ac.cn [CAS Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen Ming [CAS Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Wang Linjiang [College of Materials Science and Engineering, Guilin University of Technology, Guangxi 541004 (China); Liu Dong [CAS Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer A direct addition reaction between palygorskite and pyromellitic dianhydride. Black-Right-Pointing-Pointer The graft of anhydride to the bound water on the external surface of palygorskite. Black-Right-Pointing-Pointer Application of palygorskite without organo-modification. - Abstract: Palygorskite covalently grafted with pyromellitic dianhydride was investigated. Untreated and grafted samples were characterized by X-ray diffraction, thermogravimetry, and Fourier transform infrared spectroscopy. Infrared results showed the direct grafting of anhydride onto the bound water molecules on the external surfaces of the palygorskite. The grafting modification makes palygorskite more readily compatible with anhydride, resulting in substantial enhancements in the glass transition temperature and flexural strength of the anhydride-cured epoxy resin/palygorskite nanocomposites.

  15. Transverse dynamics of dispersive Alfven waves. I. Direct numerical evidence of filamentation

    International Nuclear Information System (INIS)

    The three-dimensional dynamics of a small-amplitude monochromatic Alfven wave propagating along an ambient magnetic field is simulated by direct numerical integration of the Hall-magnetohydrodynamics equations. As predicted by the two-dimensional nonlinear Schroedinger equation or by more general amplitude equations retaining the coupling to low-frequency magnetosonic waves, the transverse instability of the pump leads to wave collapse and formation of intense magnetic filaments, in spite of the presence of competing, possibly linearly dominant, instabilities that in some instances distort the above structures. In computational boxes, including a large number of pump wavelengths, an early arrest of the collapse is possible under the effect of quasi-transverse instabilities that drive magnetosonic waves and also prescribe the directions of the filaments

  16. Patient Responses to Incentives in Consumer-directed Health Plans: Evidence from Pharmaceuticals

    OpenAIRE

    Huckfeldt, Peter J; Amelia Haviland; Ateev Mehrotra; Zachary Wagner; Neeraj Sood

    2015-01-01

    Prior studies suggest that consumer-directed health plans (CDHPs) -characterized by high deductibles and health care accounts- reduce health costs, but there is concern that enrollees indiscriminately reduce use of low-value services (e.g., unnecessary emergency department use) and high-value services (e.g., preventive care). We investigate how CDHP enrollees change use of pharmaceuticals for chronic diseases. We compare two large firms where nearly all employees were switched to CDHPs to fir...

  17. Evidence for transmission of bluetongue virus serotype 26 through direct contact.

    Directory of Open Access Journals (Sweden)

    Carrie Batten

    Full Text Available The aim of this study was to assess the mechanisms of transmission of bluetongue virus serotype 26 (BTV-26 in goats. A previous study, which investigated the pathogenicity and infection kinetics of BTV-26 in goats, unexpectedly revealed that one control goat may have been infected through a direct contact transmission route. To investigate the transmission mechanisms of BTV-26 in more detail an experimental infection study was carried out in which three goats were infected with BTV-26, three goats were kept uninfected, but were housed in direct contact with the infected goats, and an additional four goats were kept in indirect contact separated from infected goats by metal gates. This barrier allowed the goats to have occasional face-to-face contact in the same airspace, but feeding, watering, sampling and environmental cleaning was carried out separately. The three experimentally infected goats did not show clinical signs of BTV, however high levels of viral RNA were detected and virus was isolated from their blood. At 21 dpi viral RNA was detected in, and virus was isolated from the blood of the three direct contact goats, which also seroconverted. The four indirect barrier contact goats remained uninfected throughout the duration of the experiment. In order to assess replication in a laboratory model species of Culicoides biting midge, more than 300 Culicoides sonorensis were fed a BTV-26 spiked blood meal and incubated for 7 days. The dissemination of BTV-26 in individual C. sonorensis was inferred from the quantity of virus RNA and indicated that none of the insects processed at day 7 possessed transmissible infections. This study shows that BTV-26 is easily transmitted through direct contact transmission between goats, and the strain does not seem to replicate in C. sonorensis midges using standard incubation conditions.

  18. How important is Foreign Direct Investment to Economic Growth? New Evidence from Nigeria

    OpenAIRE

    Owolabi-Merus, Olasunkanmi

    2015-01-01

    This study investigates the impact that Foreign Direct Investment (FDI) has on economic growth in Nigeria through the use of annual secondary data from 1981 to 2013 collected from the World Bank’s Africa Development Indicators. The econometric methodologies used in this research are Ordinary Least Squares (OLS), ADF unit root and the Granger Causality tests. The OLS results shows that FDI positively contributes to economic growth in Nigeria, but not statistically significant at the 5% level o...

  19. THE EFFECT OF FOREIGN DIRECT INVESTMENT ON LABOUR PRODUCTIVITY: EVIDENCE FROM ESTONIA AND SLOVENIA

    OpenAIRE

    Priit Vahter

    2004-01-01

    This paper studies the effects of foreign direct investment on labour productivity in manufacturing industries of two transition countries, Estonia and Slovenia. The emphasis is on the dimension of export/local market orientation. The study is based on firm-level panel data. It is shown that in Estonia the export oriented foreign investment enterprises have on average much lower labour productivity level than the domestic market oriented foreign affiliates. In Slovenia, on the contrary, the e...

  20. Informal interactions between audit committees and internal audit functions: exploratory evidence and directions for future research

    OpenAIRE

    Mahbub Zaman

    2013-01-01

    Purpose:This paper recognises the importance of informal processes within corporate governance and complements existing research in this area by investigating factors associated with the existence of informal interactions between audit committees and internal audit functions and in providing directions for future research.Design/Methodology/Approach:To examine the existence and drivers of informal interactions between audit committees and internal audit functions, this paper relies on a quest...

  1. The impact of foreign direct investment on host country exports: Sector based evidence from Indonesian manufacturing

    OpenAIRE

    Rudy Rahmaddi; Masaru Ichihashi

    2012-01-01

    This study sought to elucidate the existence of a link between foreign direct investment (FDI) and exports in the manufacturing sectors of Indonesia. It contributes to the literature by investigating the sector-based impact of inward FDI on a host country's exports, using disaggregated data of manufacturing sectors categorized by factor intensity from 1990 to 2008. So doing enables one to test an FDI-substitute or FDI-complementary effect on sector-based export performance. The FDI theory pro...

  2. FOREIGN DIRECT INVESTMENT AND EMPLOYMENT IN MANUFACTURING AND SERVICES SECTORS: FRESH EMPIRICAL EVIDENCE FROM SINGAPORE

    OpenAIRE

    Koi Nyen Wong; Tuck Cheong Tang

    2008-01-01

    Manufacturing and services have been regarded as the ???twin engines' of growth for Singapore economy. As the economy is moving up the value chain from downstream to upstream activities, a significant proportion of FDI (foreign direct investment) has been attracted to the manufacturing and services sectors. This paper examines the causal relationships between inward FDI and the host country's employment in these two sectors using tri-variate VAR (vector autoregressive) framework. The main fin...

  3. Anxiety and Reading Difficulties in Early Elementary School: Evidence for Unidirectional- or Bi-Directional Relations?

    OpenAIRE

    Grills-Taquechel, Amie E.; Fletcher, Jack M.; Vaughn, Sharon R.; Stuebing, Karla K.

    2012-01-01

    The present study examined competing models of the bi-directional influences of anxiety and reading achievement. Participants were 153 ethnically-diverse children (84 male, 69 female) from general education classes evaluated in the winter and spring of their first-grade academic year. Children completed standardized measures of reading achievement involving decoding and fluency along with an anxiety rating scale. Hierarchical linear regression analyses revealed that separation anxiety symptom...

  4. Direct evidence of lymphatic function improvement after advanced pneumatic compression device treatment of lymphedema

    OpenAIRE

    Adams, Kristen E.; Rasmussen, John C.; Darne, Chinmay; Tan, I-Chih; Aldrich, Melissa B.; Marshall, Milton V.; Fife, Caroline E.; Maus, Erik A.; Smith, Latisha A.; Guilloid, Renie; Hoy, Sunday; Sevick-Muraca, Eva M.

    2010-01-01

    Lymphedema affects up to 50% of all breast cancer survivors. Management with pneumatic compression devices (PCDs) is controversial, owing to the lack of methods to directly assess benefit. This pilot study employed an investigational, near-infrared (NIR) fluorescence imaging technique to evaluate lymphatic response to PCD therapy in normal control and breast cancer-related lymphedema (BCRL) subjects. Lymphatic propulsion rate, apparent lymph velocity, and lymphatic vessel recruitment were mea...

  5. Preventing malaria in pregnancy through community-directed interventions: evidence from Akwa Ibom State, Nigeria

    Directory of Open Access Journals (Sweden)

    Ishola Gbenga

    2011-08-01

    Full Text Available Abstract Background Despite massive anti-malaria campaigns across the subcontinent, effective access to intermittent preventive treatment (IPTp and insecticide-treated nets (ITNs among pregnant women remain low in large parts of sub-Saharan Africa. The slow uptake of malaria prevention products appears to reflect lack of knowledge and resistance to behavioural change, as well as poor access to resources, and limited support of programmes by local communities and authorities. Methods A recent community-based programme in Akwa Ibom State, Nigeria, is analysed to determine the degree to which community-directed interventions can improve access to malaria prevention in pregnancy. Six local government areas in Southern Nigeria were selected for a malaria in pregnancy prevention intervention. Three of these local government areas were selected for a complementary community-directed intervention (CDI programme. Under the CDI programme, volunteer community-directed distributors (CDDs were appointed by each village and kindred in the treatment areas and trained to deliver ITNs and IPTp drugs as well as basic counseling services to pregnant women. Findings Relative to women in the control area, an additional 7.4 percent of women slept under a net during pregnancy in the treatment areas (95% CI [0.035, 0.115], p-value Conclusion The presented results suggest that the inclusion of community-based programmes can substantially increase effective access to malaria prevention, and also increase access to formal health care access in general, and antenatal care attendance in particular in combination with supply side interventions. Given the relatively modest financial commitments they require, community-directed programmes appear to be a cost-effective way to improve malaria prevention; the participatory approach underlying CDI programmes also promises to strengthen ties between the formal health sector and local communities.

  6. Direct Experimental Evidence of Exciton-Phonon Bound States in Carbon Nanotubes

    OpenAIRE

    Plentz, Flavio; Henrique B. Ribeiro; Jorio, Ado; Pimenta, Marcos A.; Strano, Michael S.

    2005-01-01

    We present direct experimental observation of exciton-phonon bound states in the photoluminescence excitation spectra of isolated single walled carbon nanotubes in aqueous suspension. The photoluminescence excitation spectra from several distinct single-walled carbon nanotubes show the presence of at least one sideband related to the tangential modes, lying {200 meV} above the main absorption/emission peak. Both the energy position and line shapes of the sidebands are in excellent agreement w...

  7. The timing of foreign direct investment under uncertainty: Evidence from the Spanish banking sector

    OpenAIRE

    Garcia Bland??n, Josep

    1999-01-01

    This paper investigates the timing of foreign direct investment (FDI) in the banking sector. The importance of this issue would arise from the existence of differential benefits associated to be the first entrant in a foreign location. Nevertheless, when uncertainty is considered, the existence of some Ownership-Location-Internalization (OLI) advantages can make FDI less reversible and/or more delayable and therefore it may be optimal for the firm to delay the investme...

  8. Evaluation of direct and indirect effects of the PPARγ agonist troglitazone on mouse endothelial cell proliferation.

    Science.gov (United States)

    Kakiuchi-Kiyota, Satoko; Arnold, Lora L; Yokohira, Masanao; Koza-Taylor, Petra; Suzuki, Shugo; Varney, Michelle; Pennington, Karen L; Cohen, Samuel M

    2011-12-01

    Peroxisome proliferator-activated receptor gamma (PPARγ) agonists and PPARγ/α dual agonists are used in the treatment of type 2 diabetes mellitus and hyperlipidemias. In carcinogenicity studies, some of these agonists induced hemangiomas/hemangiosarcomas in mice, but not in rats. We hypothesized that increased endothelial cell (EC) proliferation may be involved in the mechanism of PPAR agonist-induced vascular tumors in mice. We previously showed that the sarcomagenic PPARγ agonist troglitazone (TG) increased EC proliferation in brown and white adipose tissue and liver in mice at sarcomagenic doses (400 and 800 mg/kg) after four weeks of treatment. In vitro, TG had a mitogenic effect on mouse microvascular mouse ECs by increasing cell proliferation and survival. The current studies showed that treatment of mouse ECs in vitro induced alterations in proliferation pathway gene expression, especially the expression of insulin-like growth factor-1, but had no effect on mouse oxidative stress pathways. In vivo, treatment with vitamin E did not inhibit TG-induced EC proliferation in liver and adipose tissue. In addition, no hypoxic effect was detected in adipose tissue of TG-treated mice; however, TG had a minor effect on hepatocellular hypoxia. These results provide additional evidence supporting a direct mitogenic effect in the mode of action of TG-induced hemangiosarcomas in mice. PMID:21937740

  9. State of direct fuel cell/turbine systems development

    Science.gov (United States)

    Ghezel-Ayagh, Hossein; Walzak, Jim; Patel, Dilip; Daly, Joseph; Maru, Hans; Sanderson, Robert; Livingood, William

    FuelCell Energy Inc. (FCE) is actively developing fuel cell/gas turbine hybrid systems, DFC/T ®, for generation of clean electric power with very high efficiencies. The gas turbine extends the high efficiency of the fuel cell without the need for supplementary fuel. Key features of the DFC/T system include: electrical efficiencies of up to 75% on natural gas (60% on coal gas), minimal emissions, simple design, reduced carbon dioxide release to the environment, and potential cost competitiveness with existing combined cycle power plants. FCE successfully completed sub-MW scale proof-of-concept tests (pre-alpha DFC/T hybrid power plant). The tests demonstrated that the concept results in higher power plant efficiency. A small packaged natural gas fueled sub-MW unit is being developed for demonstrations (alpha and beta units). Also, the preliminary design of a 40 MW power plant including the key equipment layout and the site plan was completed.

  10. Direct Utilization of Coal Syngas in High Temperature Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Celik, Ismail B. [West Virginia University, Morgantown, WV (United States)

    2014-10-30

    This EPSCoR project had two primary goals: (i) to build infrastructure and work force at WVU to support long-term research in the area of fuel cells and related sciences; (ii) study effects of various impurities found in coal-syngas on performance of Solid Oxide Fuel Cells (SOFC). As detailed in this report the WVU research team has made significant accomplishments in both of these areas. What follows is a brief summary of these accomplishments: State-of-the-art test facilities and diagnostic tools have been built and put into use. These include cell manufacturing, half-cell and full-cell test benches, XPS, XRD, TEM, Raman, EDAX, SEM, EIS, and ESEM equipment, unique in-situ measurement techniques and test benches (Environmental EM, Transient Mass-Spectrometer-MS, and IR Optical Temperature measurements). In addition, computational capabilities have been developed culminating in a multi-scale multi-physics fuel cell simulation code, DREAM-SOFC, as well as a Beowulf cluster with 64 CPU units. We have trained 16 graduate students, 10 postdoctoral fellows, and recruited 4 new young faculty members who have actively participated in the EPSCoR project. All four of these faculty members have already been promoted to the tenured associate professor level. With the help of these faculty and students, we were able to secure 14 research awards/contracts amounting to a total of circa $5.0 Million external funding in closely related areas of research. Using the facilities mentioned above, the effects of PH3, HCl, Cl2, and H2S on cell performance have been studied in detail, mechanisms have been identified, and also remedies have been proposed and demonstrated in the laboratory. For example, it has been determined that PH3 reacts rapidly with Ni to from secondary compounds which may become softer or even melt at high temperature and then induce Ni migration to the surface of the cell changing the material and micro-structural properties of the cell drastically. It is found that

  11. Coordinated switching of bacterial flagellar motors: evidence for direct motor-motor coupling?

    OpenAIRE

    Hu, Bo; Tu, Yuhai

    2013-01-01

    The swimming of Escherichia coli is powered by its multiple flagellar motors. Each motor spins either clockwise (CW) or counterclockwise (CCW), under the control of an intracellular regulator, CheY-P. There can be two mechanisms (extrinsic and intrinsic) to coordinate the switching of bacterial motors. The extrinsic one arises from the fact that different motors in the same cell sense a common input (CheY-P) which fluctuates near the motors' response threshold. An alternative, intrinsic mecha...

  12. Further evidence against a direct genotoxic mode of action for arsenic-induced cancer

    International Nuclear Information System (INIS)

    Arsenic in drinking water, a mixture of arsenite and arsenate, is associated with increased skin and other cancers in Asia and Latin America, but not the United States. Arsenite alone in drinking water does not cause skin cancers in experimental animals; therefore, it is not a complete carcinogen in skin. We recently showed that low concentrations of arsenite enhanced the tumorigenicity of solar UV irradiation in hairless mice, suggesting arsenic cocarcinogenesis with sunlight in skin cancer and perhaps with different carcinogenic partners for lung and bladder tumors. Cocarcinogenic mechanisms could include blocking DNA repair, stimulating angiogenesis, altering DNA methylation patterns, dysregulating cell cycle control, induction of aneuploidy and blocking apoptosis. Arsenicals are documented clastogens but not strong mutagens, with weak mutagenic activity reported at highly toxic concentrations of inorganic arsenic. Previously, we showed that arsenite, but not monomethylarsonous acid (MMA[III]), induced delayed mutagenesis in HOS cells. Here, we report new data on the mutagenicity of the trivalent methylated arsenic metabolites MMA(III) and dimethylarsinous acid [DMA(III)] at the gpt locus in Chinese hamster G12 cells. Both methylated arsenicals seemed mutagenic with apparent sublinear dose responses. However, significant mutagenesis occurred only at highly toxic concentrations of MMA(III). Most mutants induced by MMA(III) and DMA(III) exhibited transgene deletions. Some non-deletion mutants exhibited altered DNA methylation. A critical discussion of cell survival leads us to conclude that clastogenesis occurs primarily at highly cytotoxic arsenic concentrations, casting further doubt as to whether a genotoxic mode of action (MOA) for arsenicals is supportable

  13. Vitamin B6 and colorectal cancer: Current evidence and future directions

    OpenAIRE

    Zhang, Xue-Hong; Ma, Jing; Smith-Warner, Stephanie A.; Lee, Jung Eun; Giovannucci, Edward

    2013-01-01

    Colorectal cancer remains the third most common cancer in both women and men worldwide. Identifying modifiable dietary factors is crucial in developing primary prevention strategies. Vitamin B6 is involved in more than 100 coenzyme reactions, and may influence colorectal cancer risk in multiple ways including through its role in one-carbon metabolism related DNA synthesis and methylation and by reducing inflammation, cell proliferation, and oxidative stress. Observational studies of dietary o...

  14. Prevention of Post-Traumatic Stress Disorder After Trauma: Current Evidence and Future Directions.

    Science.gov (United States)

    Qi, Wei; Gevonden, Martin; Shalev, Arieh

    2016-02-01

    Post-traumatic stress disorder (PTSD) is a frequent, tenacious, and disabling consequence of traumatic events. The disorder's identifiable onset and early symptoms provide opportunities for early detection and prevention. Empirical findings and theoretical models have outlined specific risk factors and pathogenic processes leading to PTSD. Controlled studies have shown that theory-driven preventive interventions, such as cognitive behavioral therapy (CBT), or stress hormone-targeted pharmacological interventions, are efficacious in selected samples of survivors. However, the effectiveness of early clinical interventions remains unknown, and results obtained in aggregates (large groups) overlook individual heterogeneity in PTSD pathogenesis. We review current evidence of PTSD prevention and outline the need to improve the disorder's early detection and intervention in individual-specific paths to chronic PTSD. PMID:26800995

  15. Have we found conclusive evidence for dark matter through direct detection experiments?

    CERN Document Server

    Yang, J

    2013-01-01

    We employ a SUSY-model-independent method to examine the remaining evidence for the low mass dark matter. Using the XENON100's recent result of 224.6 live days $\\times$ 34kg exposure and PICASSO's result published in 2009, we have obtained a constrain of couplings, $\\| {{a_n}} \\| < 0.6$ and $\\| {{a_p}} \\| < 1.0$, corresponding to the spin-dependent cross section of ${\\sigma_n} < 5.6 \\times {10^{- 38}}$cm$^{2}$ and ${\\sigma_p} < 1.6 \\times {10^{- 37}}$cm$^{2}$. Spin-independent isospin violating dark matter model also failed to reconcile the recent result from XENON100 with the positive results from DAMA and CoGeNT.

  16. Computational model of cell positioning: directed and collective migration in the intestinal crypt epithelium

    OpenAIRE

    Wong, Shek Yoon; Chiam, K.-H.; Lim, Chwee Teck; Matsudaira, Paul

    2010-01-01

    The epithelium of the intestinal crypt is a dynamic tissue undergoing constant regeneration through cell growth, cell division, cell differentiation and apoptosis. How the epithelial cells maintain correct positioning and how they migrate in a directed and collective fashion are still not well understood. In this paper, we developed a computational model to elucidate these processes. We show that differential adhesion between epithelial cells, caused by the differential activation of EphB rec...

  17. Evidence for a Melanin Cell Wall Component in Pneumocystis carinii

    OpenAIRE

    Icenhour, Crystal R.; Kottom, Theodore J.; Limper, Andrew H.

    2003-01-01

    Fluorescein isothiocyanate-labeled monoclonal antibodies specific for fungal melanin were used in this study to visualize melanin-like components of the Pneumocystis carinii cell wall. A colorimetric enzyme assay confirmed these findings. This is the first report of melanin-like pigments in Pneumocystis.

  18. Evidence for local dendritic cell activation in pulmonary sarcoidosis

    Directory of Open Access Journals (Sweden)

    Berge Bregje

    2012-04-01

    Full Text Available Abstract Background Sarcoidosis is a granulomatous disease characterized by a seemingly exaggerated immune response against a difficult to discern antigen. Dendritic cells (DCs are pivotal antigen presenting cells thought to play an important role in the pathogenesis. Paradoxically, decreased DC immune reactivity was reported in blood samples from pulmonary sarcoidosis patients. However, functional data on lung DCs in sarcoidosis are lacking. We hypothesized that at the site of disease DCs are mature, immunocompetent and involved in granuloma formation. Methods We analyzed myeloid DCs (mDCs and plasmacytoid DCs (pDCs in broncho-alveolar lavage (BAL and blood from newly diagnosed, untreated pulmonary sarcoidosis patients and healthy controls using 9-color flowcytometry. DCs, isolated from BAL using flowcytometric sorting (mDCs or cultured from monocytes (mo-DCs, were functionally assessed in a mixed leukocyte reaction with naïve allogeneic CD4+ T cells. Using Immunohistochemistry, location and activation status of CD11c+DCs was assessed in mucosal airway biopsies. Results mDCs in BAL, but not in blood, from sarcoidosis patients were increased in number when compared with mDCs from healthy controls. mDCs purified from BAL of sarcoidosis patients induced T cell proliferation and differentiation and did not show diminished immune reactivity. Mo-DCs from patients induced increased TNFα release in co-cultures with naïve allogeneic CD4+ T cells. Finally, immunohistochemical analyses revealed increased numbers of mature CD86+ DCs in granuloma-containing airway mucosal biopsies from sarcoidosis patients. Conclusion Taken together, these finding implicate increased local DC activation in granuloma formation or maintenance in pulmonary sarcoidosis.

  19. Mast cells are important modifiers of autoimmune disease: With so much evidence, why is there controversy?

    Directory of Open Access Journals (Sweden)

    Melissa Ann Brown

    2012-06-01

    Full Text Available There is abundant evidence that mast cells are active participants in events that mediate tissue damage in autoimmune disease. Disease-associated increases in mast cell numbers accompanied by mast cell degranulation and elaboration of numerous mast cell mediators at sites of inflammation are commonly observed in many human autoimmune diseases including multiple sclerosis, rheumatoid arthritis and bullous pemphigoid. In animal models, treatment with mast cell stabilizing drugs or mast cell ablation can result in diminished disease. A variety of receptors including those engaged by antibody, complement, pathogens and intrinsic danger signals are implicated in mast cell activation in disease. Similar to their role as first responders in infection settings, mast cells likely orchestrate early recruitment of immune cells, including neutrophils, to the sites of autoimmune destruction. This co-localization promotes cellular crosstalk and activation and results in the amplification of the local inflammatory response thereby promoting and sustaining tissue damage. Despite the evidence, there is still a debate regarding the relative role of mast cells in these processes. However, by definition, mast cells can only act as accessory cells to the self-reactive T and/or antibody driven autoimmune responses. Thus, when evaluating mast cell involvement using existing and somewhat imperfect animal models of disease, their importance is sometimes obscured. However, these potent immune cells are undoubtedly major contributors to autoimmunity and should be considered as important targets for therapeutic disease intervention.

  20. Trade costs and the pattern of Foreign Direct Investment: evidence from five EU countries

    OpenAIRE

    Cardamone, Paola; Scoppola, Margherita

    2012-01-01

    Abstract According to the theoretical models of the multinational enterprise, trade costs play a fundamental role in determining the pattern of foreign direct investment (FDI). The aim of this paper is to assess the impact of trade policies on the outward stocks of FDI of the EU. We estimate a model based on the knowledge-capital theory of the multinational enterprise over the period 1995-2008 by using a sample of five EU countries and 26 partner countries. We consider, first, manufacturing s...

  1. The determinants of foreign direct investment: what is the evidence for Africa?

    OpenAIRE

    Moreira, Sandrina Berthault

    2009-01-01

    Abstract: The main purpose of the present paper is to provide an overall analysis of recent studies that both focus on Africa and examine the various factors that attract or deter Foreign Direct Investment (FDI) in Africa, in order to find answers to the following question: What are the determinants / impediments of FDI to Africa? To that end I have based my research on the articles published in all the economic journals found in the Econlit database from January 1969 up to May 2007. The keyw...

  2. Foreign direct investment in Vietnam: Is there any evidence of technological spillover effects

    OpenAIRE

    Nguyen, Anh Ngoc; Nguyen, Thang; Le, Dang Trung; Pham, Quang Ngoc; Nguyen, Dinh Chuc; Nguyen, Duc Nhat

    2008-01-01

    In the context of integrating more deeply into the world economy the Vietnamese policy makers have undertaken several measures to attract foreign direct investment to the country, with the culmination of FDI inflows in 2007 reaching over USD 20 billion, an increase of 69% over 2006. The policy has been taken on the ground that the FDI inflows will create employment and bring along the much needed technological advances, which will spill over to domestic firms. In this paper, we use a firm-le...

  3. Evidences of Superconductivity without Direct Relation to Valence Electron Density in Metal Doped Y123 Cuprates

    OpenAIRE

    Wang, Xiao-Xia; Yu, Guo-Ru; Li, Jiang-Hui; Li, Ping-Lin

    2011-01-01

    We investigated systemically YBa2Cu3-x(Fe, Co, Al, Zn)xO7-{\\delta} (x=0.0\\sim0.5) cuprates through the XRD, the test of superconductivity, oxygen contents,positron annihilation technology and simulated calculations. The experimental results and theoretic calculations support such a conclusion that the Tc does not depend directly on the density of valence electron in the samples. Moreover, whether or not it may imply some correlations between Fe-oxide superconductors and cuprates that Fe doped...

  4. Direct evidence for Sb as a Zn site impurity in ZnO

    CERN Document Server

    Wahl, U; Mendonça, T; Decoster, S

    2009-01-01

    The lattice location of ion implanted antimony in zinc oxide has been determined by means of $\\beta^{-}$-emission channeling from the radioactive $^{124}$Sb isotope. Following 30 keV implantation of $^{124}$Sb into a single-crystalline ZnO sample to a fluence of $1 \\times 10^{14}$ cm$^{−2}$, the angular-dependent emission rate of $\\beta^{-}$−particles around several crystallographic directions was measured with a position-sensitive Si detector. The majority of Sb was found to occupy Zn sites, with the possible fraction on O sites being at maximum 5%–6%.

  5. Direct evidence for Sb as a Zn site impurity in ZnO

    CERN Document Server

    Wahl, U; Mendonça, T; Decoster, S

    2009-01-01

    The lattice location of ion implanted antimony in zinc oxide has been determined by means of β− emission channeling from the radioactive b isotope. Following 30 keV implantation of b into a single-crystalline ZnO sample to a fluence of 1×1014 cm−2, the angular-dependent emission rate of β− particles around several crystallographic directions was measured with a position-sensitive Si detector. The majority of Sb was found to occupy Zn sites, with the possible fraction on O sites being at maximum 5%–6%.

  6. Analysis of primary cilia in directional cell migration in fibroblasts

    DEFF Research Database (Denmark)

    Christensen, Søren Tvorup; Veland, Iben; Schwab, Albrecht;

    2013-01-01

    Early studies of migrating fibroblasts showed that primary cilia orient in front of the nucleus and point toward the leading edge. Recent work has shown that primary cilia coordinate a series of signaling pathways critical to fibroblast cell migration during development and in wound healing. In p...

  7. Investigation of in vitro bone cell adhesion and proliferation on Ti using direct current stimulation

    International Nuclear Information System (INIS)

    Our objective was to establish an in vitro cell culture protocol to improve bone cell attachment and proliferation on Ti substrate using direct current stimulation. For this purpose, a custom made electrical stimulator was developed and a varying range of direct currents, from 5 to 25 μA, was used to study the current stimulation effect on bone cells cultured on conducting Ti samples in vitro. Cell–material interaction was studied for a maximum of 5 days by culturing with human fetal osteoblast cells (hFOB). The direct current was applied in every 8 h time interval and the duration of electrical stimulation was kept constant at 15 min for all cases. In vitro results showed that direct current stimulation significantly favored bone cell attachment and proliferation in comparison to nonstimulated Ti surface. Immunochemistry and confocal microscopy results confirmed that the cell adhesion was most pronounced on 25 μA direct current stimulated Ti surfaces as hFOB cells expressed higher vinculin protein with increasing amount of direct current. Furthermore, MTT assay results established that cells grew 30% higher in number under 25 μA electrical stimulation as compared to nonstimulated Ti surface after 5 days of culture period. In this work we have successfully established a simple and cost effective in vitro protocol offering easy and rapid analysis of bone cell–material interaction which can be used in promotion of bone cell attachment and growth on Ti substrate using direct current electrical stimulation in an in vitro model. - Highlights: ► D.C. stimulation was used to enhance in vitro bone cell adhesion and proliferation. ► Cells cultured on Ti were stimulated by using a custom made electrical stimulator. ► Optimization was performed by using a varying range of direct currents ∼ 5 to 25 μA. ► 25 μA stimulation was found most beneficial for promotion of cell adhesion/growth.

  8. Does Foreign Direct Investment Affect Green Growth? Evidence from China’s Experience

    Directory of Open Access Journals (Sweden)

    Shujing Yue

    2016-02-01

    Full Text Available Foreign Direct Investment (FDI not only affects the economic growth but also affects the environmental protection of the host country. With China’s background of pursuing green growth, we need to consider the performance of FDI from the economic and environmental benefit aspects. On this basis, using slacks-based measure directional distance function (SBMDDF to build up green growth efficiency, economic efficiency and environmental efficiency indexes, empirical research on FDI in 104 Chinese cities from 2004 to 2011 has shown that: (1 Different cities have differences in their green growth efficiency. Shenzhen city is always efficient in green economic growth. (2 Overall, FDI is positive on Chinese cities’ green growth. (3 When the green growth efficiency is broken down into economic efficiency and environmental efficiency, FDI promotes China’s economic green growth through both environmental benefits and economic benefits. (4 The effect of FDI differs in different sectors. FDI in the emission-intensive sector promotes green efficiency mainly through the improvement of economic efficiency. FDI in the non-emission-intensive sector promotes economic efficiency, environmental efficiency and green efficiency.

  9. Direct Electrochemical Evidence of the Dissociation and Adsorption Behavior of Acetonitrile at Gold Electrodes by Ultrafast Voltammetry

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Ultrafast cyclic voltammetry was used to study the redox behavior of a gold electrode in acetonitrile. The direct electrochemical evidence of the dissociation and adsorption behavior of acetonitrile at gold electrodes was found. It could be stated that two consecutive redox paths are involved, each with a special adsorption state acting as the reaction intermediate. The mean value,obtained of the electron-transfer rate constant of the second path, was 1.3 × 105 s-1 with a standard deviation of 0.24 × 105 s-1.

  10. Direct evidence for fluid mixing processes during formation of post-Variscan, unconformity-related hydrothermal vein deposits

    OpenAIRE

    Fußwinkel, Tobias

    2013-01-01

    Post-Variscan hydrothermal vein deposits are widespread in central Europe and are associated with enrichments in Pb-Zn-Cu-(Ag), Mn-Fe or Co-Ni-Bi. Their formation is commonly explained by fluid mixing processes. However, direct evidence for the occurrence of such processes on the scale of individual ore veins is rare, and as a result their efficiency on these scales is still disputed. Using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICPMS), multi-element analyses of indiv...

  11. Starch and cellulose as fuel sources for low temperature direct mode fuel cells

    OpenAIRE

    Spets, J.-P; KIROS, YOHANNES; Kuosa, M. A.; Rantanen, J; Sallinen, J.; Lampinen, M. J.; Saari, K

    2008-01-01

    This paper is a study about a direct mode fuel cell with a near-neutral-state and alkaline electrolytes. The aim of study was to develop a fuel cell, which operates directly by mixing the fuel with the electrolyte. This arrangement helps to avoid inserting membranes and additional bacterial cultures in fuel cell. The target is also to create a fuel cell with a capacity of few mWcm-2 with the starch as a fuel. Also, glucose and sorbitol have been tested as fuel for the fuel cell. QC 20111124

  12. The 22-Year Hale Cycle in Cosmic Ray Flux - Evidence for Direct Heliospheric Modulation

    CERN Document Server

    Thomas, Simon R; Lockwood, Mike

    2013-01-01

    The ability to predict times of greater galactic cosmic ray (GCR) fluxes is important for reducing the hazards caused by these particles to satellite communications, aviation, or astronauts. The 11-year solar cycle variation in cosmic rays is highly correlated with the strength of the heliospheric magnetic field. Differences in GCR flux during alternate solar cycles yield a 22-year cycle, known as the Hale Cycle, which is thought to be due to different particle drift patterns when the northern solar pole has predominantly positive (denoted a qA>0 cycle) or negative (qA0 cycles than for qA0 and more sharply peaked for qA0 solar cycles, when the difference in GCR flux is most apparent. This suggests that particle drifts may not be the sole mechanism responsible for the Hale Cycle in GCR flux at Earth. However, it is also demonstrated that these polarity-dependent heliospheric differences are evident during the space-age but much less clear in earlier data: using geomagnetic reconstructions, it is shown that for...

  13. A Bidirectional Relationship between Executive Function and Health Behavior: Evidence, Implications, and Future Directions

    Science.gov (United States)

    Allan, Julia L.; McMinn, David; Daly, Michael

    2016-01-01

    Physically active lifestyles and other health-enhancing behaviors play an important role in preserving executive function into old age. Conversely, emerging research suggests that executive functions facilitate participation in a broad range of healthy behaviors including physical activity and reduced fatty food, tobacco, and alcohol consumption. They do this by supporting the volition, planning, performance monitoring, and inhibition necessary to enact intentions and override urges to engage in health damaging behavior. Here, we focus firstly on evidence suggesting that health-enhancing behaviors can induce improvements in executive function. We then switch our focus to findings linking executive function to the consistent performance of health-promoting behaviors and the avoidance of health risk behaviors. We suggest that executive function, health behavior, and disease processes are interdependent. In particular, we argue that a positive feedback loop may exist whereby health behavior-induced changes in executive function foster subsequent health-enhancing behaviors, which in turn help sustain efficient executive functions and good health. We conclude by outlining the implications of this reciprocal relationship for intervention strategies, the design of research studies, and the study of healthy aging. PMID:27601977

  14. First direct evidence of sedimentary carbonate recycling in subduction-related xenoliths.

    Science.gov (United States)

    Liu, Yongsheng; He, Detao; Gao, Changgui; Foley, Stephen; Gao, Shan; Hu, Zhaochu; Zong, Keqing; Chen, Haihong

    2015-01-01

    Carbon in rocks and its rate of exchange with the exosphere is the least understood part of the carbon cycle. The amount of carbonate subducted as sediments and ocean crust is poorly known, but essential to mass balance the cycle. We describe carbonatite melt pockets in mantle peridotite xenoliths from Dalihu (northern China), which provide firsthand evidence for the recycling of carbonate sediments within the subduction system. These pockets retain the low trace element contents and δ(18)OSMOW = 21.1 ± 0.3 of argillaceous carbonate sediments, representing wholesale melting of carbonates instead of filtered recycling of carbon by redox freezing and melting. They also contain microscopic diamonds, partly transformed to graphite, indicating that depths >120 km were reached, as well as a bizarre mixture of carbides and metal alloys indicative of extremely reducing conditions. Subducted carbonates form diapirs that move rapidly upwards through the mantle wedge, reacting with peridotite, assimilating silicate minerals and releasing CO2, thus promoting their rapid emplacement. The assimilation process produces very local disequilibrium and divergent redox conditions that result in carbides and metal alloys, which help to interpret other occurrences of rock exhumed from ultra-deep conditions. PMID:26100577

  15. Direct Evidence for Outflow of Metal-enriched Gas Along the Radio Jets of Hydra A

    CERN Document Server

    Kirkpatrick, C C; Cavagnolo, K W; McNamara, B R; David, L P; Nulsen, P E J; Wise, M W

    2009-01-01

    Using deep Chandra observations of the Hydra A galaxy cluster, we examine the metallicity structure near the central galaxy and along its powerful radio source. We show that the metallicity of the intracluster medium is enhanced by up to 0.2 dex along the radio jets and lobes compared to the metallicity of the undisturbed gas. The enhancements extend from a radius of 20 kpc from the central galaxy to a distance of ~ 120 kpc. We estimate the total iron mass that has been transported out of the central galaxy to be between 2 x 10^7 M_sun and 7 x 10^7 M_sun which represents 10% - 20% of the iron mass within the central galaxy. The energy required to lift this gas is roughly 1% to 5% of the total energetic output of the AGN. Evidently, Hydra A's powerful radio source is able to redistribute metal-enriched, low entropy gas throughout the core of the galaxy cluster. The short re-enrichment time scale < 10^9 yr implies that the metals lost from the central galaxy will be quickly replenished.

  16. DIRECT EVIDENCE FOR OUTFLOW OF METAL-ENRICHED GAS ALONG THE RADIO JETS OF HYDRA A

    International Nuclear Information System (INIS)

    Using deep Chandra observations of the Hydra A galaxy cluster, we examine the metallicity structure near the central galaxy and along its powerful radio source. We show that the metallicity of the intracluster medium is enhanced by up to 0.2 dex along the radio jets and lobes compared to the metallicity of the undisturbed gas. The enhancements extend from a radius of 20 kpc from the central galaxy to a distance of ∼120 kpc. We estimate the total iron mass that has been transported out of the central galaxy to be between 2 x 107 M sun and 7 x 107 M sun, which represents 10%-30% of the iron mass within the central galaxy. The energy required to lift this gas is roughly 1% to 5% of the total energetic output of the active galactic nuclei. Evidently, Hydra A's powerful radio source is able to redistribute metal-enriched, low entropy gas throughout the core of the galaxy cluster. The short re-enrichment timescale 9 yr implies that the metals lost from the central galaxy will be quickly replenished.

  17. Catalytic Enhancement of Carbon Black and Coal-Fueled Hybrid Direct Carbon Fuel Cells

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Ippolito, Davide; Kammer Hansen, Kent

    2015-01-01

    Hybrid direct carbon fuel cells (HDCFCs) consisting of a solid carbon (carbon black)-molten carbonate ((62–38 wt% Li-K)2CO3) mixtures in the anode chamber of an anode-supported solid oxide fuel cell type full-cell are tested for their electrochemical performance between 700 and 800°C. Performance...

  18. EXPORTS, FOREIGN DIRECT INVESTMENT AND ECONOMIC GROWTH: EMPIRICAL EVIDENCE FROM MALAYSIA (1971-2013

    Directory of Open Access Journals (Sweden)

    Muhammad Haseeb

    2014-01-01

    Full Text Available The main objective of this study is to empirically investigate the relationship between exports, Foreign Direct Investment (FDI and the economic growth in Malaysia. Records of annual time series data from the year 1971 till 2013 have been utilized for this purpose. Upon testing the data for stationarity, the Auto Regressive Distributed Lag (ARDL model has been applied for the purpose of empirical investigation. The empirical results indicate that the productivity factor and externality effect of exports on the non-export sector are found to be statistically, positively significant, with the exports also having a positive impact on the economic growth and FDI of the country. The results support Exports Led Growth (ELG and FDI-Led economic Growth (FLG in Malaysia. The finding further suggests that Malaysia should continuous pursue exports promotion and a liberal investment economic policy in order to maintain and bolster overall economic growth.

  19. Measurement of direct CP violation in the NA48 experiment; Mise en evidence de la violation directe de CP par l'experience NA48

    Energy Technology Data Exchange (ETDEWEB)

    Formica, A

    2001-10-01

    The 2 first chapters of this thesis are dedicated to the theoretical and experimental aspects of CP violation. The NA48 experiment is a third generation experiment like KTeV, NA48 has been designed to collect data concerning the simultaneous detection of the 4 decay modes: K{sub L,S} {yields} {pi}{pi} and to provide the measurement of the parameter of direct CP violation with an uncertainty nearing 2*10{sup -4}. The third chapter describes the experimental equipment of NA48 in CERN: the production of K{sub L} and K{sub S} beams, the tagging system, the detection system for K {yields} {pi}{sup +}{pi}{sup -}, the detection system for K {yields} {pi}{sup 0}{pi}{sup 0}, the data acquisition system, and the trigger system. Chapter 4 is dedicated to the selection and identification of events. Chapter 5 deals with specific problems concerning the detection of {pi}{sup +}{pi}{sup -}, it means: the dead time in the triggering system, the overflow of the chamber reading system and the inefficiency of shift chambers. Chapter 6 lists the different corrections and systematic errors concerning the double ratio R, and gives the following result: Re({epsilon}'/{epsilon}=(14.4{+-}2.6)*10{sup -4}) which is by itself, for the first time, an evidence of direct violation. (A.C.)

  20. Direct Induction of Trophoblast Stem Cells from Murine Fibroblasts.

    Science.gov (United States)

    Kubaczka, Caroline; Senner, Claire E; Cierlitza, Monika; Araúzo-Bravo, Marcos J; Kuckenberg, Peter; Peitz, Michael; Hemberger, Myriam; Schorle, Hubert

    2015-11-01

    Trophoblast stem cells (TSCs) arise from the first cell fate decision in the developing embryo and generate extra-embryonic lineages, giving rise to the fetal portion of the placenta. Mouse embryonic and extra-embryonic lineages are strictly separated by a distinct epigenetic barrier, which is not fully overcome following expression of TSC-determining factors in embryonic stem cells. Here, we show that transient expression of Tfap2c, Gata3, Eomes, and Ets2 is sufficient to reprogram mouse embryonic fibroblasts and post-natal tail-tip-derived fibroblasts into induced TSCs (iTSCs) and surmount the epigenetic barrier separating somatic from extra-embryonic lineages. iTSCs share nearly identical morphological characteristics, gene expression profiles, and DNA methylation patterns with blastocyst-derived TSCs. Furthermore, iTSCs display transgene-independent self-renewal, differentiate along extra-embryonic lineages, and chimerize host placentas following blastocyst injection. These findings provide insights into the transcription factor networks governing TSC identity and opportunities for studying the epigenetic barriers underlying embryonic and extra-embryonic lineage segregation. PMID:26412560

  1. Type I interferons directly inhibit regulatory T cells to allow optimal antiviral T cell responses during acute LCMV infection

    OpenAIRE

    Srivastava, Shivani; Koch, Meghan A.; Pepper, Marion; Campbell, Daniel J.

    2014-01-01

    Regulatory T (T reg) cells play an essential role in preventing autoimmunity but can also impair clearance of foreign pathogens. Paradoxically, signals known to promote T reg cell function are abundant during infection and could inappropriately enhance T reg cell activity. How T reg cell function is restrained during infection to allow the generation of effective antiviral responses remains largely unclear. We demonstrate that the potent antiviral type I interferons (IFNs) directly inhibit co...

  2. Direct evidence for maternal inheritance of bacterial symbionts in small deep-sea clams (Bivalvia: Vesicomyidae)

    Science.gov (United States)

    Szafranski, Kamil M.; Gaudron, Sylvie M.; Duperron, Sébastien

    2014-05-01

    Bacterial symbiont transmission is a key step in the renewal of the symbiotic interaction at each host generation, and different modes of transmission can be distinguished. Vesicomyidae are chemosynthetic bivalves from reducing habitats that rely on symbiosis with sulfur-oxidizing bacteria, in which two studies suggesting vertical transmission of symbionts have been published, both limited by the imaging techniques used. Using fluorescence in situ hybridization and transmission electron microscopy, we demonstrate that bacterial symbionts of Isorropodon bigoti, a gonochoristic Vesicomyidae from the Guiness cold seep site, occur intracellularly within female gametes at all stages of gametogenesis from germ cells to mature oocytes and in early postlarval stage. Symbionts are completely absent from the male gonad and gametes. This study confirms the transovarial transmission of symbionts in Vesicomyidae and extends it to the smaller species for which no data were previously available.

  3. Direct evidence of advantage of using nanosized zeolite Beta for ISFET-based biosensor construction

    International Nuclear Information System (INIS)

    Analytical characteristics of urease- and butyrylcholinesterase (BuChE)- based ion sensitive field-effect transistor (ISFET) biosensors were investigated by the incorporation of zeolite Beta nanoparticles with varying Si/Al ratios. The results obtained by the zeolite-modified ISFET transducers suggested that the Si/Al ratio strongly influenced the biosensor performances due to the electrostatic interactions among enzyme, substrate, and zeolite surface as well as the nature of the enzymatic reaction. Using relatively small nanoparticles (62.7 ± 10, 76.2 ± 10, and 77.1 ± 10 nm) rather than larger particles, that are widely used in the literature, allow us to produce more homogenous products which will give more control over the quantity of materials used on the electrode surface and ability to change solely Si/Al ratio without changing other parameters such as particle size, pore volume, and surface area. This should enable the investigation of the individual effect of changing acidic and electronic nature of this material on the biosensor characteristics. According to our results, high biosensor sensitivity is evident on nanosize and submicron size particles, with the former resulting in higher performance. The sensitivity of biosensors modified by zeolite particles is higher than that to the protein for both types of biosensors. Most significantly, our results show that the performance of constructed ISFET-type biosensors strongly depends on Si/Al ratio of employed zeolite Beta nanoparticles as well as the type of enzymatic reaction employed. All fabricated biosensors demonstrated high signal reproducibility and stability for both BuChE and urease.

  4. Designing a light fabric metamaterial being highly macroscopically tough under directional extension: first experimental evidence

    Science.gov (United States)

    dell'Isola, Francesco; Lekszycki, Tomasz; Pawlikowski, Marek; Grygoruk, Roman; Greco, Leopoldo

    2015-12-01

    In this paper, we study a metamaterial constructed with an isotropic material organized following a geometric structure which we call pantographic lattice. This relatively complex fabric was studied using a continuous model (which we call pantographic sheet) by Rivlin and Pipkin and includes two families of flexible fibers connected by internal pivots which are, in the reference configuration, orthogonal. A rectangular specimen having one side three times longer than the other is cut at 45° with respect to the fibers in reference configuration, and it is subjected to large-deformation plane-extension bias tests imposing a relative displacement of shorter sides. The continuum model used, the presented numerical models and the extraordinary advancements of the technology of 3D printing allowed for the design of some first experiments, whose preliminary results are shown and seem to be rather promising. Experimental evidence shows three distinct deformation regimes. In the first regime, the equilibrium total deformation energy depends quadratically on the relative displacement of terminal specimen sides: Applied resultant force depends linearly on relative displacement. In the second regime, the applied force varies nonlinearly on relative displacement, but the behavior remains elastic. In the third regime, damage phenomena start to occur until total failure, but the exerted resultant force continues to be increasing and reaches a value up to several times larger than the maximum shown in the linear regime before failure actually occurs. Moreover, the total energy needed to reach structural failure is larger than the maximum stored elastic energy. Finally, the volume occupied by the material in the fabric is a small fraction of the total volume, so that the ratio weight/resistance to extension is very advantageous. The results seem to require a refinement of the used theoretical and numerical methods to transform the presented concept into a promising technological

  5. First direct evidence of chalcolithic footwear from the near eastern highlands.

    Directory of Open Access Journals (Sweden)

    Ron Pinhasi

    Full Text Available In 2008, a well preserved and complete shoe was recovered at the base of a Chalcolithic pit in the cave of Areni-1, Armenia. Here, we discuss the chronology of this find, its archaeological context and its relevance to the study of the evolution of footwear. Two leather samples and one grass sample from the shoe were dated at the Oxford Radiocarbon Accelerator Unit (ORAU. A third leather sample was dated at the University of California-Irvine Accelerator Mass Spectrometry Facility (UCIAMS. The R_Combine function for the three leather samples provides a date range of 3627-3377 Cal BC (95.4% confidence interval and the calibrated range for the straw is contemporaneous (3627-3377 Cal BC. The shoe was stuffed with loose, unfastened grass (Poaceae without clear orientation which was more than likely used to maintain the shape of the shoe and/or prepare it for storage. The shoe is 24.5 cm long (European size 37, 7.6 to 10 cm wide, and was made from a single piece of leather that wrapped around the foot. It was worn and shaped to the wearer's right foot, particularly around the heel and hallux where the highest pressure is exerted in normal gait. The Chalcolithic shoe provides solid evidence for the use of footwear among Old World populations at least since the Chalcolithic. Other 4th millennium discoveries of shoes (Italian and Swiss Alps, and sandals (Southern Israel indicate that more than one type of footwear existed during the 4th millennium BC, and that we should expect to discover more regional variations in the manufacturing and style of shoes where preservation conditions permit.

  6. First direct evidence of chalcolithic footwear from the near eastern highlands.

    Science.gov (United States)

    Pinhasi, Ron; Gasparian, Boris; Areshian, Gregory; Zardaryan, Diana; Smith, Alexia; Bar-Oz, Guy; Higham, Thomas

    2010-01-01

    In 2008, a well preserved and complete shoe was recovered at the base of a Chalcolithic pit in the cave of Areni-1, Armenia. Here, we discuss the chronology of this find, its archaeological context and its relevance to the study of the evolution of footwear. Two leather samples and one grass sample from the shoe were dated at the Oxford Radiocarbon Accelerator Unit (ORAU). A third leather sample was dated at the University of California-Irvine Accelerator Mass Spectrometry Facility (UCIAMS). The R_Combine function for the three leather samples provides a date range of 3627-3377 Cal BC (95.4% confidence interval) and the calibrated range for the straw is contemporaneous (3627-3377 Cal BC). The shoe was stuffed with loose, unfastened grass (Poaceae) without clear orientation which was more than likely used to maintain the shape of the shoe and/or prepare it for storage. The shoe is 24.5 cm long (European size 37), 7.6 to 10 cm wide, and was made from a single piece of leather that wrapped around the foot. It was worn and shaped to the wearer's right foot, particularly around the heel and hallux where the highest pressure is exerted in normal gait. The Chalcolithic shoe provides solid evidence for the use of footwear among Old World populations at least since the Chalcolithic. Other 4th millennium discoveries of shoes (Italian and Swiss Alps), and sandals (Southern Israel) indicate that more than one type of footwear existed during the 4th millennium BC, and that we should expect to discover more regional variations in the manufacturing and style of shoes where preservation conditions permit. PMID:20543959

  7. First direct evidence of chalcolithic footwear from the near eastern highlands.

    LENUS (Irish Health Repository)

    Pinhasi, Ron

    2010-01-01

    In 2008, a well preserved and complete shoe was recovered at the base of a Chalcolithic pit in the cave of Areni-1, Armenia. Here, we discuss the chronology of this find, its archaeological context and its relevance to the study of the evolution of footwear. Two leather samples and one grass sample from the shoe were dated at the Oxford Radiocarbon Accelerator Unit (ORAU). A third leather sample was dated at the University of California-Irvine Accelerator Mass Spectrometry Facility (UCIAMS). The R_Combine function for the three leather samples provides a date range of 3627-3377 Cal BC (95.4% confidence interval) and the calibrated range for the straw is contemporaneous (3627-3377 Cal BC). The shoe was stuffed with loose, unfastened grass (Poaceae) without clear orientation which was more than likely used to maintain the shape of the shoe and\\/or prepare it for storage. The shoe is 24.5 cm long (European size 37), 7.6 to 10 cm wide, and was made from a single piece of leather that wrapped around the foot. It was worn and shaped to the wearer\\'s right foot, particularly around the heel and hallux where the highest pressure is exerted in normal gait. The Chalcolithic shoe provides solid evidence for the use of footwear among Old World populations at least since the Chalcolithic. Other 4th millennium discoveries of shoes (Italian and Swiss Alps), and sandals (Southern Israel) indicate that more than one type of footwear existed during the 4th millennium BC, and that we should expect to discover more regional variations in the manufacturing and style of shoes where preservation conditions permit.

  8. Cytocompatibility of direct water synthesized cadmium selenide quantum dots in colo-205 cells

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Torres, Marcos R. [Universidad Metropolitana, Nanomaterials Science Laboratory, School of Science and Technology (United States); Velez, Christian; Zayas, Beatriz [Universidad Metropolitana, ChemTox Laboratory, School of Environmental Affairs (United States); Rivera, Osvaldo [Universidad Metropolitana, Nanomaterials Science Laboratory, School of Science and Technology (United States); Arslan, Zikri [Jackson State University, Department of Chemistry (United States); Gonzalez-Vega, Maxine N. [Universidad Metropolitana, Nanomaterials Science Laboratory, School of Science and Technology (United States); Diaz-Diestra, Daysi; Beltran-Huarac, Juan; Morell, Gerardo [University of Puerto Rico, Molecular Science Research Center (United States); Primera-Pedrozo, Oliva M., E-mail: oprimera1@suagm.edu [Universidad Metropolitana, Nanomaterials Science Laboratory, School of Science and Technology (United States)

    2015-06-15

    Cadmium selenide quantum dots (CdSe QDs), inorganic semiconducting nanocrystals, are alluring increased attraction due to their highly refined chemistry, availability, and super tunable optical properties suitable for many applications in different research areas, such as photovoltaics, light-emitting devices, environmental sciences, and nanomedicine. Specifically, they are being widely used in bio-imaging in contrast to organic dyes due to their high brightness and improved photo-stability, and their ability to tune their absorption and emission spectra upon changing the crystal size. The production of CdSe QDs is mostly assisted by trioctylphosphine oxide compound, which acts as solvent or solubilizing agent and renders the QDs soluble in organic compounds (such as toluene, chloroform, and hexane) that are highly toxic. To circumvent the toxicity-related factor in CdSe QDs, we report the synthesis of CdSe QDs capped with thioglycolic acid (TGA) in an aqueous medium, and their biocompatibility in colo-205 cancer cells. In this study, the [Cd{sup 2+}]/[TGA] ratio was adjusted to 11:1 and the Se concentration (10 and 15 mM) was monitored in order to evaluate its influence on the optical properties and cytocompatibility. QDs resulted to be quite stable in water (after purification) and RPMI cell medium and no precipitation was observed for long contact times, making them appealing for in vitro experiments. The spectroscopy analysis, advanced electron microscopy, and X-ray diffractometry studies indicate that the final products were successfully formed exhibiting an improved optical response. Colo-205 cells being exposed to different concentrations of TGA-capped CdSe QDs for 12, 24, and 48 h with doses ranging from 0.5 to 2.0 mM show high tolerance reaching cell viabilities as high as 93 %. No evidence of cellular apoptotic pathways was observed as pointed out by our Annexin V assays at higher concentrations. Moreover, confocal microscopy analysis conducted to

  9. Cytocompatibility of direct water synthesized cadmium selenide quantum dots in colo-205 cells

    International Nuclear Information System (INIS)

    Cadmium selenide quantum dots (CdSe QDs), inorganic semiconducting nanocrystals, are alluring increased attraction due to their highly refined chemistry, availability, and super tunable optical properties suitable for many applications in different research areas, such as photovoltaics, light-emitting devices, environmental sciences, and nanomedicine. Specifically, they are being widely used in bio-imaging in contrast to organic dyes due to their high brightness and improved photo-stability, and their ability to tune their absorption and emission spectra upon changing the crystal size. The production of CdSe QDs is mostly assisted by trioctylphosphine oxide compound, which acts as solvent or solubilizing agent and renders the QDs soluble in organic compounds (such as toluene, chloroform, and hexane) that are highly toxic. To circumvent the toxicity-related factor in CdSe QDs, we report the synthesis of CdSe QDs capped with thioglycolic acid (TGA) in an aqueous medium, and their biocompatibility in colo-205 cancer cells. In this study, the [Cd2+]/[TGA] ratio was adjusted to 11:1 and the Se concentration (10 and 15 mM) was monitored in order to evaluate its influence on the optical properties and cytocompatibility. QDs resulted to be quite stable in water (after purification) and RPMI cell medium and no precipitation was observed for long contact times, making them appealing for in vitro experiments. The spectroscopy analysis, advanced electron microscopy, and X-ray diffractometry studies indicate that the final products were successfully formed exhibiting an improved optical response. Colo-205 cells being exposed to different concentrations of TGA-capped CdSe QDs for 12, 24, and 48 h with doses ranging from 0.5 to 2.0 mM show high tolerance reaching cell viabilities as high as 93 %. No evidence of cellular apoptotic pathways was observed as pointed out by our Annexin V assays at higher concentrations. Moreover, confocal microscopy analysis conducted to evaluate

  10. Theory of direct sunlight transmission through orthogonal screen cells

    International Nuclear Information System (INIS)

    The Purpose of this paper is to investigate the feasibility of using the Rawshan screens to control high light intensity and to avoid excessive solar radiation penetrating inside the building interior. The exploration of the environmental characteristics of this device indicates an ideal solution to utilize available daylight in the arid atmosphere, reduces energy consumption due to the us of artificial light and ensures the continuity of the traditional architecture and the country heritage. A systematic analysis of direct sunlight transmission has been explored using a mathematical approach. The study intends to construct a predictive tool for the architects through which different specifications of the Rawshan screens were identified as far as direct beam of light concerned. The predictive tool was set-up to investigate various parameters of the screen such as the screen configurations, the aperture configurations, the change in orientation and the effect of the sky condition. The analysis of light transmission through the screen were set-up for orthogonal shapes

  11. Biochemical and microscopic evidence for the internalization and degradation of heparin-containing mast cell granules by bovine endothelial cells

    International Nuclear Information System (INIS)

    Incubation of [35S]heparin-containing mast cell granules with cultured bovine endothelial cells was followed by the appearance of 35S-granule-associated radioactivity within the endothelial cells and a decrease in radioactivity in the extracellular fluid. These changes occurred during the first 24 hours of incubation and suggested ingestion of the mast cell granules by the endothelial cells. Periodic electron microscopic examination of the monolayers confirmed this hypothesis by demonstrating apposition of the granules to the plasmalemma of endothelial cells, which was followed by the engulfment of the granules by cytoplasmic projections. Under light microscopic examination, mast cell granules within endothelial cells then appeared to undergo degradation. The degradation of [35S]heparin in mast cell granules was demonstrated by a decrease in the amount of intracellular [35S]heparin proteoglycan after 24 hours and the appearance of free [35S]sulfate in the extracellular compartment. Intact endothelial cells were more efficient at degrading [35S]heparin than were cell lysates or cell supernatants. These data provide evidence of the ability of endothelial cells to ingest mast cell granules and degrade native heparin that is presented as a part of the mast cell granule

  12. Examination of Cell Shape in Wall Thickness Direction for Foamed Polyurethane Resin

    Science.gov (United States)

    Kono, Tsutomu; Matsuoka, Shin-Ichi; Araki, Kuninari; Iseki, Takashi

    The foaming flow process of polyurethane resin is difficult because temperature, density and thermal conductivity are changed greatly by heat generation resulting from the mixing reaction of polyol and polyisocyanate resin. It is thought that thermal conductivity and strength are influenced by cell shape after the foaming process. In this study, we evaluate three-dimensional cell shapes by quantitatively observation of the ratio of the diameter of the parallel and the perpendicular section to flow direction, the ratio of the major axis and the minor axis, and direction of the major axis of cells for closed cell shapes in foamed polyurethane resin. It is thought that cell shapes are mainly deformed by shear stress and pressure of adjacent cells. It becomes obvious by cell shape evaluation that cells in the skin layer are compressed in the thickness direction by pressure of adjacent cells, cells between the skin layer and the core layer are stretched perpendicular to the flow direction by shear stress, and cells in the core layer are similar to the sphere shape.

  13. µc-Si solar cells by direct deposition with APCVD

    Czech Academy of Sciences Publication Activity Database

    Rachow, T.; Ledinský, Martin; Janz, S.; Reber, S.; Fejfar, Antonín

    München: WIP Wirtschaft und Infrastruktur GmbH & Co Planungs KG, 2012 - (Nowak, S.), s. 2386-2392 ISBN 3-936338-28-0. [European Photovoltaic Solar Energy Conference and Exhibition (PVSEC) /17./. Frankfurt (DE), 24.09.2012-28.09.2012] R&D Projects: GA MŠk 7E10061; GA MŠk(CZ) LM2011026 EU Projects: European Commission(XE) 240826 - POLYSIMODE Institutional research plan: CEZ:AV0Z10100521 Keywords : epitaxy * thin film solar cell * a-Si/µ-Si * microcrystalline silicon * Si film Subject RIV: BM - Solid Matter Physics ; Magnetism

  14. Evidence for a direct collapse black hole in the Lyman α source CR7

    Science.gov (United States)

    Smith, Aaron; Bromm, Volker; Loeb, Abraham

    2016-08-01

    Throughout the epoch of reionization, the most luminous Lyα emitters are capable of ionizing their own local bubbles. The CR7 galaxy at z ≈ 6.6 stands out for its combination of exceptionally bright Lyα and He II 1640 Å line emission but absence of metal lines. As a result CR7 may be the first viable candidate host of a young primordial starburst or direct collapse black hole. High-resolution spectroscopy reveals a +160 km s-1 velocity offset between the Lyα and He II line peaks while the spatial extent of the Lyα emitting region is ˜16 kpc. The observables are indicative of an outflow signature produced by a strong central source. We present one-dimensional radiation-hydrodynamics simulations incorporating accurate Lyα feedback and ionizing radiation to investigate the nature of the CR7 source. We find that a Population III star cluster with 105 K blackbody emission ionizes its environment too efficiently to generate a significant velocity offset. However, a massive black hole with a non-thermal Compton-thick spectrum is able to reproduce the Lyα signatures as a result of higher photon trapping and longer potential lifetime. For both sources, Lyα radiation pressure turns out to be dynamically important.

  15. Evidence for a direct collapse black hole in the Lyman-alpha source CR7

    CERN Document Server

    Smith, Aaron; Loeb, Abraham

    2016-01-01

    Throughout the epoch of reionization the most luminous Ly{\\alpha} emitters are capable of ionizing their own local bubbles. The CR7 galaxy at $z \\approx 6.6$ stands out for its combination of exceptionally bright Ly{\\alpha} and HeII 1640 Angstrom line emission but absence of metal lines. As a result CR7 may be the first viable candidate host of a young primordial starburst or direct collapse black hole. High-resolution spectroscopy reveals a +160 km s$^{-1}$ velocity offset between the Ly{\\alpha} and HeII line peaks while the spatial extent of the Ly{\\alpha} emitting region is $\\sim 16$ kpc. The observables are indicative of an outflow signature produced by a strong central source. We present one-dimensional radiation-hydrodynamics simulations incorporating accurate Ly{\\alpha} feedback and ionizing radiation to investigate the nature of the CR7 source. We find that a Population III star cluster with $10^5$ K blackbody emission ionizes its environment too efficiently to generate a significant velocity offset. ...

  16. Direct evidence for sequence-dependent attraction between double-stranded DNA controlled by methylation

    Science.gov (United States)

    Yoo, Jejoong; Kim, Hajin; Aksimentiev, Aleksei; Ha, Taekjip

    2016-03-01

    Although proteins mediate highly ordered DNA organization in vivo, theoretical studies suggest that homologous DNA duplexes can preferentially associate with one another even in the absence of proteins. Here we combine molecular dynamics simulations with single-molecule fluorescence resonance energy transfer experiments to examine the interactions between duplex DNA in the presence of spermine, a biological polycation. We find that AT-rich DNA duplexes associate more strongly than GC-rich duplexes, regardless of the sequence homology. Methyl groups of thymine acts as a steric block, relocating spermine from major grooves to interhelical regions, thereby increasing DNA-DNA attraction. Indeed, methylation of cytosines makes attraction between GC-rich DNA as strong as that between AT-rich DNA. Recent genome-wide chromosome organization studies showed that remote contact frequencies are higher for AT-rich and methylated DNA, suggesting that direct DNA-DNA interactions that we report here may play a role in the chromosome organization and gene regulation.

  17. Dopaminergic modulation of positive expectations for goal-directed action: evidence from Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    Noham eWolpe

    2015-10-01

    Full Text Available Parkinson’s disease (PD impairs the control of movement and cognition, including the planning of action and its consequences. This provides the opportunity to study the dopaminergic influences on the perception and awareness of action. Here we examined the perception of the outcome of a goal-directed action made by medicated patients with PD. A visuomotor task probed the integration of sensorimotor signals with the positive expectations of outcomes (Self priors, which in healthy adults bias perception towards success in proportion to trait optimism. We tested the hypotheses that (i the priors on the perception of the consequences of one’s own actions differ between patients and age- and sex-matched controls, and (ii that these priors are modulated by the levodopa dose equivalent in patients. There was no overall difference between patients and controls in the perceptual priors used. However, the precision of patient priors was inversely related to their levodopa dose equivalent. Patients with high levodopa dose equivalent showed more accurate priors, representing predictions that were closer to the true distribution of performance. Such accuracy has previously been demonstrated when observing the actions of others, suggesting abnormal awareness of action in these patients. These results confirm a link between dopamine and the positive expectation of the outcome of one’s own actions, and may have implications for the management of PD.

  18. Evidence for the direct decay of the 125 GeV Higgs boson to fermions

    CERN Document Server

    Chatrchyan, Serguei; Sirunyan, Albert M; Tumasyan, Armen; Adam, Wolfgang; Bergauer, Thomas; Dragicevic, Marko; Erö, Janos; Fabjan, Christian; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hartl, Christian; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Kiesenhofer, Wolfgang; Knünz, Valentin; Krammer, Manfred; Krätschmer, Ilse; Liko, Dietrich; Mikulec, Ivan; Rabady, Dinyar; Rahbaran, Babak; Rohringer, Herbert; Schöfbeck, Robert; Strauss, Josef; Taurok, Anton; Treberer-Treberspurg, Wolfgang; Waltenberger, Wolfgang; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Alderweireldt, Sara; Bansal, Monika; Bansal, Sunil; Cornelis, Tom; De Wolf, Eddi A; Janssen, Xavier; Knutsson, Albert; Luyckx, Sten; Ochesanu, Silvia; Roland, Benoit; Rougny, Romain; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Blekman, Freya; Blyweert, Stijn; D'Hondt, Jorgen; Heracleous, Natalie; Kalogeropoulos, Alexis; Keaveney, James; Kim, Tae Jeong; Lowette, Steven; Maes, Michael; Olbrechts, Annik; Python, Quentin; Strom, Derek; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Villella, Ilaria; Caillol, Cécile; Clerbaux, Barbara; De Lentdecker, Gilles; Favart, Laurent; Gay, Arnaud; Léonard, Alexandre; Marage, Pierre Edouard; Mohammadi, Abdollah; Perniè, Luca; Reis, Thomas; Seva, Tomislav; Thomas, Laurent; Vander Velde, Catherine; Vanlaer, Pascal; Wang, Jian; Adler, Volker; Beernaert, Kelly; Benucci, Leonardo; Cimmino, Anna; Costantini, Silvia; Crucy, Shannon; Dildick, Sven; Garcia, Guillaume; Klein, Benjamin; Lellouch, Jérémie; Mccartin, Joseph; Ocampo Rios, Alberto Andres; Ryckbosch, Dirk; Salva Diblen, Sinem; Sigamani, Michael; Strobbe, Nadja; Thyssen, Filip; Tytgat, Michael; Walsh, Sinead; Yazgan, Efe; Zaganidis, Nicolas; Basegmez, Suzan; Beluffi, Camille; Bruno, Giacomo; Castello, Roberto; Caudron, Adrien; Ceard, Ludivine; Da Silveira, Gustavo Gil; Delaere, Christophe; Du Pree, Tristan; Favart, Denis; Forthomme, Laurent; Giammanco, Andrea; Hollar, Jonathan; Jez, Pavel; Komm, Matthias; Lemaitre, Vincent; Liao, Junhui; Militaru, Otilia; Nuttens, Claude; Pagano, Davide; Pin, Arnaud; Piotrzkowski, Krzysztof; Popov, Andrey; Quertenmont, Loic; Selvaggi, Michele; Vidal Marono, Miguel; Vizan Garcia, Jesus Manuel; Beliy, Nikita; Caebergs, Thierry; Daubie, Evelyne; Hammad, Gregory Habib; Alves, Gilvan; Correa Martins Junior, Marcos; Dos Reis Martins, Thiago; Pol, Maria Elena; Henrique Gomes E Souza, Moacyr; Aldá Júnior, Walter Luiz; Carvalho, Wagner; Chinellato, Jose; Custódio, Analu; Da Costa, Eliza Melo; De Jesus Damiao, Dilson; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Malbouisson, Helena; Malek, Magdalena; Matos Figueiredo, Diego; Mundim, Luiz; Nogima, Helio; Prado Da Silva, Wanda Lucia; Santaolalla, Javier; Santoro, Alberto; Sznajder, Andre; Tonelli Manganote, Edmilson José; Vilela Pereira, Antonio; Bernardes, Cesar Augusto; De Almeida Dias, Flavia; Tomei, Thiago; De Moraes Gregores, Eduardo; Mercadante, Pedro G; Novaes, Sergio F; Padula, Sandra; Genchev, Vladimir; Iaydjiev, Plamen; Marinov, Andrey; Piperov, Stefan; Rodozov, Mircho; Sultanov, Georgi; Vutova, Mariana; Dimitrov, Anton; Glushkov, Ivan; Hadjiiska, Roumyana; Kozhuharov, Venelin; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Chen, Mingshui; Du, Ran; Jiang, Chun-Hua; Liang, Dong; Liang, Song; Meng, Xiangwei; Plestina, Roko; Tao, Junquan; Wang, Xianyou; Wang, Zheng; Asawatangtrakuldee, Chayanit; Ban, Yong; Guo, Yifei; Li, Qiang; Li, Wenbo; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Wang, Dayong; Zhang, Linlin; Zou, Wei; Avila, Carlos; Chaparro Sierra, Luisa Fernanda; Florez, Carlos; Gomez, Juan Pablo; Gomez Moreno, Bernardo; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Polic, Dunja; Puljak, Ivica; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Kadija, Kreso; Luetic, Jelena; Mekterovic, Darko; Morovic, Srecko; Sudic, Lucija; Attikis, Alexandros; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Bodlak, Martin; Finger, Miroslav; Finger Jr, Michael; Assran, Yasser; Elgammal, Sherif; Ellithi Kamel, Ali; Mahmoud, Mohammed; Mahrous, Ayman; Radi, Amr; Kadastik, Mario; Müntel, Mait; Murumaa, Marion; Raidal, Martti; Tiko, Andres; Eerola, Paula; Fedi, Giacomo; Voutilainen, Mikko; Härkönen, Jaakko; Karimäki, Veikko; Kinnunen, Ritva; Kortelainen, Matti J; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Peltola, Timo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Wendland, Lauri; Tuuva, Tuure; Besancon, Marc; Couderc, Fabrice; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Favaro, Carlotta; Ferri, Federico; Ganjour, Serguei; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Locci, Elizabeth; Malcles, Julie; Nayak, Aruna; Rander, John; Rosowsky, André; Titov, Maksym; Baffioni, Stephanie; Beaudette, Florian; Busson, Philippe; Charlot, Claude; Daci, Nadir; Dahms, Torsten; Dalchenko, Mykhailo; Dobrzynski, Ludwik; Filipovic, Nicolas; Florent, Alice; Granier de Cassagnac, Raphael; Mastrolorenzo, Luca; Miné, Philippe; Mironov, Camelia; Naranjo, Ivo Nicolas; Nguyen, Matthew; Ochando, Christophe; Paganini, Pascal; Sabes, David; Salerno, Roberto; Sauvan, Jean-baptiste; Sirois, Yves; Veelken, Christian; Yilmaz, Yetkin; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Bloch, Daniel; Brom, Jean-Marie; Chabert, Eric Christian; Collard, Caroline; Conte, Eric; Drouhin, Frédéric; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Goetzmann, Christophe; Juillot, Pierre; Le Bihan, Anne-Catherine; Van Hove, Pierre; Gadrat, Sébastien; Beauceron, Stephanie; Beaupere, Nicolas; Boudoul, Gaelle; Brochet, Sébastien; Carrillo Montoya, Camilo Andres; Chasserat, Julien; Chierici, Roberto; Contardo, Didier; Depasse, Pierre; El Mamouni, Houmani; Fan, Jiawei; Fay, Jean; Gascon, Susan; Gouzevitch, Maxime; Ille, Bernard; Kurca, Tibor; Lethuillier, Morgan; Mirabito, Laurent; Perries, Stephane; Ruiz Alvarez, José David; Sgandurra, Louis; Sordini, Viola; Vander Donckt, Muriel; Verdier, Patrice; Viret, Sébastien; Xiao, Hong; Tsamalaidze, Zviad; Autermann, Christian; Beranek, Sarah; Bontenackels, Michael; Calpas, Betty; Edelhoff, Matthias; Feld, Lutz; Hindrichs, Otto; Klein, Katja; Ostapchuk, Andrey; Perieanu, Adrian; Raupach, Frank; Sammet, Jan; Schael, Stefan; Sprenger, Daniel; Weber, Hendrik; Wittmer, Bruno; Zhukov, Valery; Ata, Metin; Caudron, Julien; Dietz-Laursonn, Erik; Duchardt, Deborah; Erdmann, Martin; Fischer, Robert; Güth, Andreas; Hebbeker, Thomas; Heidemann, Carsten; Hoepfner, Kerstin; Klingebiel, Dennis; Knutzen, Simon; Kreuzer, Peter; Merschmeyer, Markus; Meyer, Arnd; Olschewski, Mark; Padeken, Klaas; Papacz, Paul; Reithler, Hans; Schmitz, Stefan Antonius; Sonnenschein, Lars; Teyssier, Daniel; Thüer, Sebastian; Weber, Martin; Cherepanov, Vladimir; Erdogan, Yusuf; Flügge, Günter; Geenen, Heiko; Geisler, Matthias; Haj Ahmad, Wael; Hoehle, Felix; Kargoll, Bastian; Kress, Thomas; Kuessel, Yvonne; Lingemann, Joschka; Nowack, Andreas; Nugent, Ian Michael; Perchalla, Lars; Pooth, Oliver; Stahl, Achim; Asin, Ivan; Bartosik, Nazar; Behr, Joerg; Behrenhoff, Wolf; Behrens, Ulf; Bell, Alan James; Bergholz, Matthias; Bethani, Agni; Borras, Kerstin; Burgmeier, Armin; Cakir, Altan; Calligaris, Luigi; Campbell, Alan; Choudhury, Somnath; Costanza, Francesco; Diez Pardos, Carmen; Dooling, Samantha; Dorland, Tyler; Eckerlin, Guenter; Eckstein, Doris; Eichhorn, Thomas; Flucke, Gero; Geiser, Achim; Grebenyuk, Anastasia; Gunnellini, Paolo; Habib, Shiraz; Hauk, Johannes; Hellwig, Gregor; Hempel, Maria; Horton, Dean; Jung, Hannes; Kasemann, Matthias; Katsas, Panagiotis; Kieseler, Jan; Kleinwort, Claus; Krämer, Mira; Krücker, Dirk; Lange, Wolfgang; Leonard, Jessica; Lipka, Katerina; Lohmann, Wolfgang; Lutz, Benjamin; Mankel, Rainer; Marfin, Ihar; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mnich, Joachim; Mussgiller, Andreas; Naumann-Emme, Sebastian; Novgorodova, Olga; Nowak, Friederike; Ntomari, Eleni; Perrey, Hanno; Petrukhin, Alexey; Pitzl, Daniel; Placakyte, Ringaile; Raspereza, Alexei; Ribeiro Cipriano, Pedro M; Riedl, Caroline; Ron, Elias; Sahin, Mehmet Özgür; Salfeld-Nebgen, Jakob; Saxena, Pooja; Schmidt, Ringo; Schoerner-Sadenius, Thomas; Schröder, Matthias; Stein, Matthias; Vargas Trevino, Andrea Del Rocio; Walsh, Roberval; Wissing, Christoph; Aldaya Martin, Maria; Blobel, Volker; Centis Vignali, Matteo; Enderle, Holger; Erfle, Joachim; Garutti, Erika; Goebel, Kristin; Görner, Martin; Gosselink, Martijn; Haller, Johannes; Höing, Rebekka Sophie; Kirschenmann, Henning; Klanner, Robert; Kogler, Roman; Lange, Jörn; Lapsien, Tobias; Lenz, Teresa; Marchesini, Ivan; Ott, Jochen; Peiffer, Thomas; Pietsch, Niklas; Rathjens, Denis; Sander, Christian; Schettler, Hannes; Schleper, Peter; Schlieckau, Eike; Schmidt, Alexander; Seidel, Markus; Sibille, Jennifer; Sola, Valentina; Stadie, Hartmut; Steinbrück, Georg; Troendle, Daniel; Usai, Emanuele; Vanelderen, Lukas; Barth, Christian; Baus, Colin; Berger, Joram; Böser, Christian; Butz, Erik; Chwalek, Thorsten; De Boer, Wim; Descroix, Alexis; Dierlamm, Alexander; Feindt, Michael; Guthoff, Moritz; Hartmann, Frank; Hauth, Thomas; Held, Hauke; Hoffmann, Karl-Heinz; Husemann, Ulrich; Katkov, Igor; Kornmayer, Andreas; Kuznetsova, Ekaterina; Lobelle Pardo, Patricia; Martschei, Daniel; Mozer, Matthias Ulrich; Müller, Thomas; Niegel, Martin; Nürnberg, Andreas; Oberst, Oliver; Quast, Gunter; Rabbertz, Klaus; Ratnikov, Fedor; Röcker, Steffen; Schilling, Frank-Peter; Schott, Gregory; Simonis, Hans-Jürgen; Stober, Fred-Markus Helmut; Ulrich, Ralf; Wagner-Kuhr, Jeannine; Wayand, Stefan; Weiler, Thomas; Wolf, Roger; Zeise, Manuel; Anagnostou, Georgios; Daskalakis, Georgios; Geralis, Theodoros; Giakoumopoulou, Viktoria Athina; Kesisoglou, Stilianos; Kyriakis, Aristotelis; Loukas, Demetrios; Markou, Athanasios; Markou, Christos; Psallidas, Andreas; Topsis-Giotis, Iasonas; Gouskos, Loukas; Panagiotou, Apostolos; Saoulidou, Niki; Stiliaris, Efstathios; Aslanoglou, Xenofon; Evangelou, Ioannis; Flouris, Giannis; Foudas, Costas; Jones, John; Kokkas, Panagiotis; Manthos, Nikolaos; Papadopoulos, Ioannis; Paradas, Evangelos; Bencze, Gyorgy; Hajdu, Csaba; Hidas, Pàl; Horvath, Dezso; Sikler, Ferenc; Veszpremi, Viktor; Vesztergombi, Gyorgy; Zsigmond, Anna Julia; Beni, Noemi; Czellar, Sandor; Molnar, Jozsef; Palinkas, Jozsef; Szillasi, Zoltan; Karancsi, János; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Swain, Sanjay Kumar; Beri, Suman Bala; Bhatnagar, Vipin; Dhingra, Nitish; Gupta, Ruchi; Kaur, Manjit; Mittal, Monika; Nishu, Nishu; Sharma, Archana; Singh, Jasbir; Kumar, Ashok; Kumar, Arun; Ahuja, Sudha; Bhardwaj, Ashutosh; Choudhary, Brajesh C; Kumar, Ajay; Malhotra, Shivali; Naimuddin, Md; Ranjan, Kirti; Sharma, Varun; Shivpuri, Ram Krishen; Banerjee, Sunanda; Bhattacharya, Satyaki; Chatterjee, Kalyanmoy; Dutta, Suchandra; Gomber, Bhawna; Jain, Sandhya; Jain, Shilpi; Khurana, Raman; Modak, Atanu; Mukherjee, Swagata; Roy, Debarati; Sarkar, Subir; Sharan, Manoj; Singh, Anil; Abdulsalam, Abdulla; Dutta, Dipanwita; Kailas, Swaminathan; Kumar, Vineet; Mohanty, Ajit Kumar; Pant, Lalit Mohan; Shukla, Prashant; Topkar, Anita; Aziz, Tariq; Chatterjee, Rajdeep Mohan; Ganguly, Sanmay; Ghosh, Saranya; Guchait, Monoranjan; Gurtu, Atul; Kole, Gouranga; Kumar, Sanjeev; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Mohanty, Gagan Bihari; Parida, Bibhuti; Sudhakar, Katta; Wickramage, Nadeesha; Banerjee, Sudeshna; Dewanjee, Ram Krishna; Dugad, Shashikant; Arfaei, Hessamaddin; Bakhshiansohi, Hamed; Behnamian, Hadi; Etesami, Seyed Mohsen; Fahim, Ali; Jafari, Abideh; Khakzad, Mohsen; Mohammadi Najafabadi, Mojtaba; Naseri, Mohsen; Paktinat Mehdiabadi, Saeid; Safarzadeh, Batool; Zeinali, Maryam; Grunewald, Martin; Abbrescia, Marcello; Barbone, Lucia; Calabria, Cesare; Chhibra, Simranjit Singh; Colaleo, Anna; Creanza, Donato; De Filippis, Nicola; De Palma, Mauro; Fiore, Luigi; Iaselli, Giuseppe; Maggi, Giorgio; Maggi, Marcello; My, Salvatore; Nuzzo, Salvatore; Pacifico, Nicola; Pompili, Alexis; Pugliese, Gabriella; Radogna, Raffaella; Selvaggi, Giovanna; Silvestris, Lucia; Singh, Gurpreet; Venditti, Rosamaria; Verwilligen, Piet; Zito, Giuseppe; Abbiendi, Giovanni; Benvenuti, Alberto; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Campanini, Renato; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Codispoti, Giuseppe; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Grandi, Claudio; Guiducci, Luigi; Marcellini, Stefano; Masetti, Gianni; Meneghelli, Marco; Montanari, Alessandro; Navarria, Francesco; Odorici, Fabrizio; Perrotta, Andrea; Primavera, Federica; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gian Piero; Tosi, Nicolò; Travaglini, Riccardo; Albergo, Sebastiano; Cappello, Gigi; Chiorboli, Massimiliano; Costa, Salvatore; Giordano, Ferdinando; Potenza, Renato; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Gallo, Elisabetta; Gonzi, Sandro; Gori, Valentina; Lenzi, Piergiulio; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Tropiano, Antonio; Benussi, Luigi; Bianco, Stefano; Fabbri, Franco; Piccolo, Davide; Fabbricatore, Pasquale; Ferro, Fabrizio; Lo Vetere, Maurizio; Musenich, Riccardo; Robutti, Enrico; Tosi, Silvano; Dinardo, Mauro Emanuele; Fiorendi, Sara; Gennai, Simone; Gerosa, Raffaele; Ghezzi, Alessio; Govoni, Pietro; Lucchini, Marco Toliman; Malvezzi, Sandra; Manzoni, Riccardo Andrea; Martelli, Arabella; Marzocchi, Badder; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Ragazzi, Stefano; Redaelli, Nicola; Tabarelli de Fatis, Tommaso; Buontempo, Salvatore; Cavallo, Nicola; Di Guida, Salvatore; Fabozzi, Francesco; Iorio, Alberto Orso Maria; Lista, Luca; Meola, Sabino; Merola, Mario; Paolucci, Pierluigi; Azzi, Patrizia; Bacchetta, Nicola; Bisello, Dario; Branca, Antonio; Carlin, Roberto; Checchia, Paolo; Dorigo, Tommaso; Galanti, Mario; Gasparini, Fabrizio; Gasparini, Ugo; Giubilato, Piero; Gonella, Franco; Gozzelino, Andrea; Kanishchev, Konstantin; Lacaprara, Stefano; Lazzizzera, Ignazio; Margoni, Martino; Meneguzzo, Anna Teresa; Montecassiano, Fabio; Pazzini, Jacopo; Pozzobon, Nicola; Ronchese, Paolo; Simonetto, Franco; Torassa, Ezio; Tosi, Mia; Vanini, Sara; Zotto, Pierluigi; Zucchetta, Alberto; Zumerle, Gianni; Gabusi, Michele; Ratti, Sergio P; Riccardi, Cristina; Salvini, Paola; Vitulo, Paolo; Biasini, Maurizio; Bilei, Gian Mario; Fanò, Livio; Lariccia, Paolo; Mantovani, Giancarlo; Menichelli, Mauro; Romeo, Francesco; Saha, Anirban; Santocchia, Attilio; Spiezia, Aniello; Androsov, Konstantin; Azzurri, Paolo; Bagliesi, Giuseppe; Bernardini, Jacopo; Boccali, Tommaso; Broccolo, Giuseppe; Castaldi, Rino; Ciocci, Maria Agnese; Dell'Orso, Roberto; Donato, Silvio; Fiori, Francesco; Foà, Lorenzo; Giassi, Alessandro; Grippo, Maria Teresa; Kraan, Aafke; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Moon, Chang-Seong; Palla, Fabrizio; Rizzi, Andrea; Savoy-Navarro, Aurore; Serban, Alin Titus; Spagnolo, Paolo; Squillacioti, Paola; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Vernieri, Caterina; Barone, Luciano; Cavallari, Francesca; Del Re, Daniele; Diemoz, Marcella; Grassi, Marco; Jorda, Clara; Longo, Egidio; Margaroli, Fabrizio; Meridiani, Paolo; Micheli, Francesco; Nourbakhsh, Shervin; Organtini, Giovanni; Paramatti, Riccardo; Rahatlou, Shahram; Rovelli, Chiara; Soffi, Livia; Traczyk, Piotr; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Bellan, Riccardo; Biino, Cristina; Cartiglia, Nicolo; Casasso, Stefano; Costa, Marco; Degano, Alessandro; Demaria, Natale; Finco, Linda; Mariotti, Chiara; Maselli, Silvia; Migliore, Ernesto; Monaco, Vincenzo; Musich, Marco; Obertino, Maria Margherita; Ortona, Giacomo; Pacher, Luca; Pastrone, Nadia; Pelliccioni, Mario; Pinna Angioni, Gian Luca; Potenza, Alberto; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Solano, Ada; Staiano, Amedeo; Tamponi, Umberto; Belforte, Stefano; Candelise, Vieri; Casarsa, Massimo; Cossutti, Fabio; Della Ricca, Giuseppe; Gobbo, Benigno; La Licata, Chiara; Marone, Matteo; Montanino, Damiana; Schizzi, Andrea; Umer, Tomo; Zanetti, Anna; Chang, Sunghyun; Kim, Tae Yeon; Nam, Soon-Kwon; Kim, Dong Hee; Kim, Gui Nyun; Kim, Ji Eun; Kim, Min Suk; Kong, Dae Jung; Lee, Sangeun; Oh, Young Do; Park, Hyangkyu; Sakharov, Alexandre; Son, Dong-Chul; Kim, Jae Yool; Kim, Zero Jaeho; Song, Sanghyeon; Choi, Suyong; Gyun, Dooyeon; Hong, Byung-Sik; Jo, Mihee; Kim, Hyunchul; Kim, Yongsun; Lee, Byounghoon; Lee, Kyong Sei; Park, Sung Keun; Roh, Youn; Choi, Minkyoo; Kim, Ji Hyun; Park, Chawon; Park, Inkyu; Park, Sangnam; Ryu, Geonmo; Choi, Young-Il; Choi, Young Kyu; Goh, Junghwan; Kwon, Eunhyang; Lee, Jongseok; Seo, Hyunkwan; Yu, Intae; Juodagalvis, Andrius; Komaragiri, Jyothsna Rani; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Heredia-de La Cruz, Ivan; Lopez-Fernandez, Ricardo; Martínez-Ortega, Jorge; Sánchez Hernández, Alberto; Villasenor-Cendejas, Luis Manuel; Carrillo Moreno, Salvador; Vazquez Valencia, Fabiola; Salazar Ibarguen, Humberto Antonio; Casimiro Linares, Edgar; Morelos Pineda, Antonio; Krofcheck, David; Butler, Philip H; Doesburg, Robert; Reucroft, Steve; Ahmad, Ashfaq; Ahmad, Muhammad; Asghar, Muhammad Irfan; Butt, Jamila; Hassan, Qamar; Hoorani, Hafeez R; Khan, Wajid Ali; Khurshid, Taimoor; Qazi, Shamona; Shah, Mehar Ali; Shoaib, Muhammad; Bialkowska, Helena; Bluj, Michal; Boimska, Bożena; Frueboes, Tomasz; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Wrochna, Grzegorz; Zalewski, Piotr; Brona, Grzegorz; Bunkowski, Karol; Cwiok, Mikolaj; Dominik, Wojciech; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Misiura, Maciej; Wolszczak, Weronika; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Nguyen, Federico; Rodrigues Antunes, Joao; Seixas, Joao; Varela, Joao; Vischia, Pietro; Golutvin, Igor; Gorbunov, Ilya; Karjavin, Vladimir; Konoplyanikov, Viktor; Korenkov, Vladimir; Kozlov, Guennady; Lanev, Alexander; Malakhov, Alexander; Matveev, Viktor; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Savina, Maria; Shmatov, Sergey; Shulha, Siarhei; Skatchkov, Nikolai; Smirnov, Vitaly; Zarubin, Anatoli; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Vorobyev, Andrey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Kirsanov, Mikhail; Krasnikov, Nikolai; Pashenkov, Anatoli; Tlisov, Danila; Toropin, Alexander; Epshteyn, Vladimir; Gavrilov, Vladimir; Lychkovskaya, Natalia; Popov, Vladimir; Safronov, Grigory; Semenov, Sergey; Spiridonov, Alexander; Stolin, Viatcheslav; Vlasov, Evgueni; Zhokin, Alexander; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Leonidov, Andrey; Mesyats, Gennady; Rusakov, Sergey V; Vinogradov, Alexey; Belyaev, Andrey; Boos, Edouard; Dubinin, Mikhail; Dudko, Lev; Ershov, Alexander; Gribushin, Andrey; Klyukhin, Vyacheslav; Kodolova, Olga; Lokhtin, Igor; Obraztsov, Stepan; Perfilov, Maxim; Petrushanko, Sergey; Savrin, Viktor; Azhgirey, Igor; Bayshev, Igor; Bitioukov, Sergei; Kachanov, Vassili; Kalinin, Alexey; Konstantinov, Dmitri; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Sobol, Andrei; Tourtchanovitch, Leonid; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Djordjevic, Milos; Ekmedzic, Marko; Milosevic, Jovan; Aguilar-Benitez, Manuel; Alcaraz Maestre, Juan; Battilana, Carlo; Calvo, Enrique; Cerrada, Marcos; Chamizo Llatas, Maria; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Domínguez Vázquez, Daniel; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Ferrando, Antonio; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Merino, Gonzalo; Navarro De Martino, Eduardo; Pérez Calero Yzquierdo, Antonio María; Puerta Pelayo, Jesus; Quintario Olmeda, Adrián; Redondo, Ignacio; Romero, Luciano; Soares, Mara Senghi; Willmott, Carlos; Albajar, Carmen; de Trocóniz, Jorge F; Missiroli, Marino; Brun, Hugues; Cuevas, Javier; Fernandez Menendez, Javier; Folgueras, Santiago; Gonzalez Caballero, Isidro; Lloret Iglesias, Lara; Brochero Cifuentes, Javier Andres; Cabrillo, Iban Jose; Calderon, Alicia; Duarte Campderros, Jordi; Fernandez, Marcos; Gomez, Gervasio; Gonzalez Sanchez, Javier; Graziano, Alberto; Lopez Virto, Amparo; Marco, Jesus; Marco, Rafael; Martinez Rivero, Celso; Matorras, Francisco; Munoz Sanchez, Francisca Javiela; Piedra Gomez, Jonatan; Rodrigo, Teresa; Rodríguez-Marrero, Ana Yaiza; Ruiz-Jimeno, Alberto; Scodellaro, Luca; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Auzinger, Georg; Bachtis, Michail; Baillon, Paul; Ball, Austin; Barney, David; Benaglia, Andrea; Bendavid, Joshua; Benhabib, Lamia; Benitez, Jose F; Bernet, Colin; Bianchi, Giovanni; Bloch, Philippe; Bocci, Andrea; Bonato, Alessio; Bondu, Olivier; Botta, Cristina; Breuker, Horst; Camporesi, Tiziano; Cerminara, Gianluca; Christiansen, Tim; Coarasa Perez, Jose Antonio; Colafranceschi, Stefano; D'Alfonso, Mariarosaria; D'Enterria, David; Dabrowski, Anne; David Tinoco Mendes, Andre; De Guio, Federico; De Roeck, Albert; De Visscher, Simon; Dobson, Marc; Dupont-Sagorin, Niels; Elliott-Peisert, Anna; Eugster, Jürg; Franzoni, Giovanni; Funk, Wolfgang; Giffels, Manuel; Gigi, Dominique; Gill, Karl; Girone, Maria; Giunta, Marina; Glege, Frank; Gomez-Reino Garrido, Robert; Gowdy, Stephen; Guida, Roberto; Hammer, Josef; Hansen, Magnus; Harris, Philip; Hegeman, Jeroen; Innocente, Vincenzo; Janot, Patrick; Karavakis, Edward; Kousouris, Konstantinos; Krajczar, Krisztian; Lecoq, Paul; Lourenco, Carlos; Magini, Nicolo; Malgeri, Luca; Mannelli, Marcello; Masetti, Lorenzo; Meijers, Frans; Mersi, Stefano; Meschi, Emilio; Moortgat, Filip; Mulders, Martijn; Musella, Pasquale; Orsini, Luciano; Palencia Cortezon, Enrique; Pape, Luc; Perez, Emmanuelle; Perrozzi, Luca; Petrilli, Achille; Petrucciani, Giovanni; Pfeiffer, Andreas; Pierini, Maurizio; Pimiä, Martti; Piparo, Danilo; Plagge, Michael; Racz, Attila; Reece, William; Rolandi, Gigi; Rovere, Marco; Sakulin, Hannes; Santanastasio, Francesco; Schäfer, Christoph; Schwick, Christoph; Sekmen, Sezen; Sharma, Archana; Siegrist, Patrice; Silva, Pedro; Simon, Michal; Sphicas, Paraskevas; Steggemann, Jan; Stieger, Benjamin; Stoye, Markus; Treille, Daniel; Tsirou, Andromachi; Veres, Gabor Istvan; Vlimant, Jean-Roch; Wöhri, Hermine Katharina; Zeuner, Wolfram Dietrich; Bertl, Willi; Deiters, Konrad; Erdmann, Wolfram; Horisberger, Roland; Ingram, Quentin; Kaestli, Hans-Christian; König, Stefan; Kotlinski, Danek; Langenegger, Urs; Renker, Dieter; Rohe, Tilman; Bachmair, Felix; Bäni, Lukas; Bianchini, Lorenzo; Bortignon, Pierluigi; Buchmann, Marco-Andrea; Casal, Bruno; Chanon, Nicolas; Deisher, Amanda; Dissertori, Günther; Dittmar, Michael; Donegà, Mauro; Dünser, Marc; Eller, Philipp; Grab, Christoph; Hits, Dmitry; Lustermann, Werner; Mangano, Boris; Marini, Andrea Carlo; Martinez Ruiz del Arbol, Pablo; Meister, Daniel; Mohr, Niklas; Nägeli, Christoph; Nef, Pascal; Nessi-Tedaldi, Francesca; Pandolfi, Francesco; Pauss, Felicitas; Peruzzi, Marco; Quittnat, Milena; Rebane, Liis; Ronga, Frederic Jean; Rossini, Marco; Starodumov, Andrei; Takahashi, Maiko; Theofilatos, Konstantinos; Wallny, Rainer; Weber, Hannsjoerg Artur; Amsler, Claude; Canelli, Maria Florencia; Chiochia, Vincenzo; De Cosa, Annapaola; Hinzmann, Andreas; Hreus, Tomas; Ivova Rikova, Mirena; Kilminster, Benjamin; Millan Mejias, Barbara; Ngadiuba, Jennifer; Robmann, Peter; Snoek, Hella; 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Xie, Wei; Xu, Lingshan; Yoo, Hwi Dong; Zablocki, Jakub; Zheng, Yu; Parashar, Neeti; Adair, Antony; Akgun, Bora; Ecklund, Karl Matthew; Geurts, Frank JM; Li, Wei; Michlin, Benjamin; Padley, Brian Paul; Redjimi, Radia; Roberts, Jay; Zabel, James; Betchart, Burton; Bodek, Arie; Covarelli, Roberto; de Barbaro, Pawel; Demina, Regina; Eshaq, Yossof; Ferbel, Thomas; Garcia-Bellido, Aran; Goldenzweig, Pablo; Han, Jiyeon; Harel, Amnon; Miner, Daniel Carl; Petrillo, Gianluca; Vishnevskiy, Dmitry; Zielinski, Marek; Bhatti, Anwar; Ciesielski, Robert; Demortier, Luc; Goulianos, Konstantin; Lungu, Gheorghe; Malik, Sarah; Mesropian, Christina; Arora, Sanjay; Barker, Anthony; Chou, John Paul; Contreras-Campana, Christian; Contreras-Campana, Emmanuel; Duggan, Daniel; Ferencek, Dinko; Gershtein, Yuri; Gray, Richard; Halkiadakis, Eva; Hidas, Dean; Lath, Amitabh; Panwalkar, Shruti; Park, Michael; Patel, Rishi; Rekovic, Vladimir; Robles, Jorge; Salur, Sevil; Schnetzer, Steve; Seitz, Claudia; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Thomassen, Peter; Walker, Matthew; Rose, Keith; Spanier, Stefan; Yang, Zong-Chang; York, Andrew; Bouhali, Othmane; Eusebi, Ricardo; Flanagan, Will; Gilmore, Jason; Kamon, Teruki; Khotilovich, Vadim; Krutelyov, Vyacheslav; Montalvo, Roy; Osipenkov, Ilya; Pakhotin, Yuriy; Perloff, Alexx; Roe, Jeffrey; Rose, Anthony; Safonov, Alexei; Sakuma, Tai; Suarez, Indara; Tatarinov, Aysen; Toback, David; Akchurin, Nural; Cowden, Christopher; Damgov, Jordan; Dragoiu, Cosmin; Dudero, Phillip Russell; Faulkner, James; Kovitanggoon, Kittikul; Kunori, Shuichi; Lee, Sung Won; Libeiro, Terence; Volobouev, Igor; Appelt, Eric; Delannoy, Andrés G; Greene, Senta; Gurrola, Alfredo; Johns, Willard; Maguire, Charles; Mao, Yaxian; Melo, Andrew; Sharma, Monika; Sheldon, Paul; Snook, Benjamin; Tuo, Shengquan; Velkovska, Julia; Arenton, Michael Wayne; Boutle, Sarah; Cox, Bradley; Francis, Brian; Goodell, Joseph; Hirosky, Robert; Ledovskoy, Alexander; Li, Hengne; Lin, Chuanzhe; Neu, Christopher; Wood, John; Gollapinni, Sowjanya; Harr, Robert; Karchin, Paul Edmund; Kottachchi Kankanamge Don, Chamath; Lamichhane, Pramod; Belknap, Donald; Borrello, Laura; Carlsmith, Duncan; Cepeda, Maria; Dasu, Sridhara; Duric, Senka; Friis, Evan; Grothe, Monika; Hall-Wilton, Richard; Herndon, Matthew; Hervé, Alain; Klabbers, Pamela; Klukas, Jeffrey; Lanaro, Armando; Lazaridis, Christos; Levine, Aaron; Loveless, Richard; Mohapatra, Ajit; Ojalvo, Isabel; Perry, Thomas; Pierro, Giuseppe Antonio; Polese, Giovanni; Ross, Ian; Sarangi, Tapas; Savin, Alexander; Smith, Wesley H; Woods, Nathaniel

    2014-01-01

    The discovery of a new boson with a mass of approximately 125 GeV in 2012 at the LHC has heralded a new era in understanding the nature of electroweak symmetry breaking and possibly completing the standard model of particle physics. Since the first observation in decays to gamma-gamma, WW, and ZZ boson pairs, an extensive set of measurements of the mass and couplings to W and Z bosons, as well as multiple tests of the spin-parity quantum numbers, have revealed that the properties of the new boson are consistent with those of the long-sought agent responsible for electroweak symmetry breaking. An important open question is whether the new particle also couples to fermions, and in particular to down-type fermions, since the current measurements mainly constrain the couplings to the up-type top quark. Determination of the couplings to down-type fermions requires direct measurement of the corresponding Higgs boson decays, as recently reported by the CMS experiment in the study of Higgs decays to bottom quarks and...

  19. Alpha 4 integrin directs virus-activated CD8+ T cells to sites of infection

    DEFF Research Database (Denmark)

    Christensen, Jan Pravsgaard; Andersson, E C; Scheynius, A; Marker, O; Thomsen, Allan Randrup

    1995-01-01

    response is induced, which is associated with marked CD8+ cell-mediated inflammation. Two expressions of LCMV-induced inflammation were studied: meningitis induced by intracerebral infection and adoptive transfer of virus-specific delayed-type hypersensitivity. Our previous studies have shown that LCMV...... infection results in the appearance of activated CD8+ cells with an increased expression of VLA-4. In this study we have compared various T cell high and low responder situations, and these experiments revealed that acute inflammation correlates directly with VLA-4 expression on splenic CD8+ cells. This...... ability to transfer virus-specific, delayed-type hypersensitivity when the donor cells were given i.v., but not when the cells were injected directly into the test site. Co-transfer of CD8-depleted cells with anti-VLA-4-blocked cells did not reveal any cooperation. Taken together, these results indicate...

  20. Young driver distraction: state of the evidence and directions for behavior change programs.

    Science.gov (United States)

    Buckley, Lisa; Chapman, Rebekah L; Sheehan, Mary

    2014-05-01

    Adolescent drivers are overrepresented in distraction-related motor vehicle crashes. A number of potential reasons for such an elevated risk include driving inexperience, high adoption of communication technology, increased peer involvement, and tendency to take risks, which render young drivers particularly vulnerable. Major legislative efforts in Graduated Licensing Systems that include passenger restrictions have shown positive effects. Restrictions on cell phone use are also being introduced; however, it is challenging to enforce such regulations. This article argues that such contextual, legislative interventions are an essential prevention strategy, but there is an unfilled need to introduce behavior change programs that may target adolescents, parents, and friends. A theoretical framework is applied in which risk and protective factors are identified from research within the contexts of community and jurisdiction. In the literature on distraction, social context and normative influences are key elements used to inform program design for adolescent drivers, with parental monitoring informing interventions targeting parents. Following from this assessment of the message content assessment, the design of strategies to deliver the messages is reviewed. In the current literature, school-based programs, simulations, and Web-delivered programs have been evaluated with supplementary strategies delivered by physicians and parents. Such developments are still at an early stage of development, and ultimately will need controlled implementation and evaluation studies. Of course, there is no likely single approach to prevent adolescent driver distraction. Complementary approaches such as the further development of technological interventions to manage phone use are needed. PMID:24759436

  1. Evidence for Differential Glycosylation of Trophoblast Cell Types.

    Science.gov (United States)

    Chen, Qiushi; Pang, Poh-Choo; Cohen, Marie E; Longtine, Mark S; Schust, Danny J; Haslam, Stuart M; Blois, Sandra M; Dell, Anne; Clark, Gary F

    2016-06-01

    Human placental villi are surfaced by the syncytiotrophoblast (STB), with a layer of cytotrophoblasts (CTB) positioned just beneath the STB. STB in normal term pregnancies is exposed to maternal immune cells in the placental intervillous space. Extravillous cytotrophoblasts (EVT) invade the decidua and spiral arteries, where they act in conjunction with natural killer (NK) cells to convert the spiral arteries into flaccid conduits for maternal blood that support a 3-4 fold increase in the rate of maternal blood flow into the placental intervillous space. The functional roles of these distinct trophoblast subtypes during pregnancy suggested that they could be differentially glycosylated. Glycomic analysis of these trophoblasts has revealed the expression of elevated levels of biantennary N-glycans in STB and CTB, with the majority of them bearing a bisecting GlcNAc. N-glycans terminated with polylactosamine extensions were also detected at low levels. A subset of the N-glycans linked to these trophoblasts were sialylated, primarily with terminal NeuAcα2-3Gal sequences. EVT were decorated with the same N-glycans as STB and CTB, except in different proportions. The level of bisecting type N-glycans was reduced, but the level of N-glycans decorated with polylactosamine sequences were substantially elevated compared with the other types of trophoblasts. The level of triantennary and tetraantennary N-glycans was also elevated in EVT. The sialylated N-glycans derived from EVT were completely susceptible to an α2-3 specific neuraminidase (sialidase S). The possibility exists that the N-glycans associated with these different trophoblast subpopulations could act as functional groups. These potential relationships will be considered. PMID:26929217

  2. Apathy in Frontotemporal Degeneration: Neuroanatomical Evidence of Impaired Goal-Directed Behavior

    Directory of Open Access Journals (Sweden)

    Lauren Massimo

    2015-11-01

    Full Text Available Background: Apathy, the major manifestation of impaired goal-directed behavior (GDB, is the most common neuropsychiatric syndrome associated with behavioral variant frontotemporal degeneration (bvFTD. The behavioral and biological mechanisms of apathy, however, are not well understood. We hypothesized that GDB has multiple components – including at least initiation, planning and motivation – and that GDB is supported by a network of multiple frontal brain regions. In this study, we examined this hypothesis by evaluating the selective breakdown of GDB in bvFTD, and relating these deficits to grey matter (GM atrophy and white matter (WM integrity. Methods: Eighteen apathetic bvFTD participants and 17 healthy controls completed the Philadelphia Apathy Computerized Test (PACT. This test quantifies each of three components of GDB hypothesized to contribute to apathy. We then used regression analyses to relate PACT scores to GM atrophy and reduced white matter (WM fractional anisotropy (FA in bvFTD. Results: Compared to controls, bvFTD participants demonstrated significant impairments in each of the three hypothesized components of GDB that contribute to apathy. Regression analyses related each component to disease in specific GM structures and associated WM tracts. Poor initiation thus was related to GM atrophy in anterior cingulate and reduced FA in the cingulum. Planning impairment was related to GM atrophy in dorsolateral prefrontal cortex and reduced FA in superior longitudinal fasciculus. Poor motivation was related to GM atrophy in orbitofrontal cortex and reduced FA in uncinate fasciculus. Conclusions: bvFTD patients have difficulty with initiation, planning and motivation components of GDB. These findings are consistent with the hypotheses that GDB encompasses at least three processes, that these are supported by a large-scale neural network within specific portions of the frontal lobe, and that degradation of any one of these prefrontal

  3. Direct evidence for coastal iodine particles from Laminaria macroalgae – linkage to emissions of molecular iodine

    Directory of Open Access Journals (Sweden)

    D. Wevill

    2004-02-01

    Full Text Available Renewal of ultrafine aerosols in the marine boundary layer may lead to repopulation of the marine distribution and ultimately determine the concentration of cloud condensation nuclei (CCN. Thus the formation of nanometre-scale particles can lead to enhanced scattering of incoming radiation and a net cooling of the atmosphere. The recent demonstration of the chamber formation of new particles from the photolytic production of condensable iodine-containing compounds from diiodomethane (CH2I2, (O'Dowd et al., 2002; Kolb, 2002; Jimenez et al., 2003a; Burkholder and Ravishankara, 2003, provides an additional mechanism to the gas-to-particle conversion of sulphuric acid formed in the photo-oxidation of dimethylsulphide for marine aerosol repopulation. CH2I2 is emitted from seaweeds (Carpenter et al., 1999, 2000 and has been suggested as an initiator of particle formation. We demonstrate here for the first time that ultrafine iodine-containing particles are produced by intertidal macroalgae exposed to ambient levels of ozone. The particle composition is very similar both to those formed in the chamber photo-oxidation of diiodomethane and in the oxidation of molecular iodine by ozone. The particles formed in all three systems are similarly aspherical and behave alike when exposed to increased humidity environments. Direct coastal boundary layer observations of molecular iodine, ultrafine particle production and iodocarbons are reported. Using a newly measured molecular iodine photolysis rate, it is shown that, if atomic iodine is involved in the observed particle bursts, it is of the order of at least 1000 times more likely to result from molecular iodine photolysis than diiodomethane photolysis. A hypothesis for molecular iodine release from intertidal macroalgae is presented and the potential importance of macroalgal iodine particles in their contribution to CCN and global radiative forcing are discussed.

  4. Hybrid direct carbon fuel cells and their reaction mechanisms - a review

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Kammer Hansen, Kent

    2014-01-01

    with carbon capture and storage (CCS) due to the high purity of CO2 emitted in the exhaust gas. Direct carbon (or coal) fuel cells (DCFCs) are directly fed with solid carbon to the anode chamber. The fuel cell converts the carbon at the anode and the oxygen at the cathode into electricity, heat and...... efforts is discussed on the fuel cell stack and system levels. The range of DCFC types can be roughly broken down into four fuel cell types: aqueous hydroxide, molten hydroxide, molten carbonate and solid oxide fuel cells. Emphasis is placed on the electrochemical reactions occurring at the anode and the...... proposed mechanism(s) of these reactions for molten carbonate, solid oxide and hybrid direct carbon fuel cells. Additionally, the criteria of choosing the ‘best’ DCFC technology is explored, including system design (continuous supply of solid fuel), performance (power density, efficiency), environmental...

  5. Human thymic epithelial cells directly induce activation of autologous immature thymocytes.

    OpenAIRE

    Denning, S M; Kurtzberg, J; Le, P. T.; Tuck, D T; Singer, K H; Haynes, B. F.

    1988-01-01

    To study the role that epithelial cells of the thymic microenvironment play in promoting activation of immature CD7+, CD2+, CD4-, CD8- (double-negative) human thymocytes, we have isolated thymocyte subsets from normal postnatal thymus and have cocultured autologous double-negative thymocytes with pure populations of thymic epithelial (TE) cells. We report that TE cells directly activate double-negative thymocytes to proliferate and that TE cells enhance the ability of double-negative thymocyt...

  6. Performance analysis for direct 2-propanol fuel-cell based on Pt containing anode electrocatalysts

    OpenAIRE

    TAPAN, Niyazi Alper; ÖZTÜRK, Ezgi

    2009-01-01

    Direct 2-propanol cell performance based on Pt containing anode electrocatalyst was evaluated. Cell performance, open circuit voltage, maximum current density, and maximum power density were measured at various alcohol concentrations and cell temperatures. 2-propanol fuel cell shows the highest performance at 1 M concentration and 80 °C operating temperature. The highest practical efficiency (at the maximum power density) was found at 2 M 2-propanol concentration and 60 °C operating ...

  7. Exploration of molecular pathways mediating electric field-directed Schwann cell migration by RNA-Seq

    OpenAIRE

    Yao, Li; Li, Yongchao; Knapp, Jennifer; Smith, Peter

    2015-01-01

    In peripheral nervous systems, Schwann cells wrap around axons of motor and sensory neurons to form the myelin sheath. Following spinal cord injury, Schwann cells regenerate and migrate to the lesion and are involved in the spinal cord regeneration process. Transplantation of Schwann cells into injured neural tissue results in enhanced spinal axonal regeneration. Effective directional migration of Schwann cells is critical in the neural regeneration process. In this study, we report that Schw...

  8. A direct evidence for high carbon dioxide and radon-222 discharge in Central Nepal

    Energy Technology Data Exchange (ETDEWEB)

    Perrier, F.; Byrdina, S. [Inst Phys Globe, UMR 7154, Equipe Geomagnetisme, F-75005 Paris (France); Univ Paris Diderot, F-75005 Paris (France); Richon, P.; Bollinger, L.; Bureau, S. [CEA Bruyeres le Chatel, DIF, Dept Anal Surveillance Environm, 91 (France); Richon, P. [Inst Phys Globe, UMR 7154, Equipe Geol Syst Volcan, F-75005 Paris (France); France-Lanord, Ch. [CNRS, Ctr Rech Petrog and Geochim, F-54501 Vandoeuvre Les Nancy (France); Rajaure, S.; Koirala, Bharat Prasad; Shrestha, Prithvi Lal; Gautam, Umesh Prasad; Tiwari, Dilli Ram; Sapkota, Soma Nath [Natl Seism Ctr, Dept Mines and Geol, Kathmandu (Nepal); Revil, A. [Colorado Sch Mines, Dept Geophys, Golden, CO 80401 (United States); Revil, A. [Univ Savoie, Equipe Volcans, CNRS, LGIT, UMR 5559, Chambery (France); Contraires, S. [Inst Phys Globe, Equipe Geomat and Environm, F-75005 Paris (France)

    2009-02-15

    Gas discharges have been identified at the Syabru-Bensi hot springs, located at the front of the High Himalaya in Central Nepal, in the Main Central Thrust zone. The hot spring waters are characterized by a temperature reaching 61 C, high salinity, high alkalinity and {delta}{sup 13}C varying from +0. 7 parts per thousand to +4. 8 parts per thousand. The gas is mainly dry carbon dioxide, with a {delta}{sup 13}C of -0. 8 parts per thousand. The diffuse carbon dioxide flux, mapped by the accumulation chamber method, reached a value of 19000 g m{sup -2}day{sup -1}, which is comparable with values measured on active volcanoes. Similar values have been observed over a two-year time interval and the integral around the main gas discharge amounts to 0. 25 {+-} 0. 07 mol s{sup -1}, or 350 {+-} 100 ton a{sup -1}. The mean radon-222 concentration in spring water did not exceed 2. 5 Bq L{sup -1}, exponentially decreasing with water temperature. In contrast, in gas bubbles collected in the water or in the dry gas discharges, the radon concentration varied from 16 000 to 41000 Bq m{sup -3}. In the soil, radon concentration varied from 25000 to more than 50000 Bq m{sup -3}. Radon flux, measured at more than fifty points, reached extreme values, larger than 2 Bq m{sup -2}s{sup -1}, correlated to the larger values of the carbon dioxide flux. Our direct observation confirms previous studies which indicated large degassing in the Himalaya. The proposed understanding is that carbon dioxide is released at mid-crustal depth by metamorphic reactions within the Indian basement, transported along pre-existing faults by meteoric hot water circulation, and degassed before reaching surface. This work, first, confirms that further studies should be undertaken to better constrain the carbon budget of the Himalaya, and, more generally, the contribution of mountain building to the global carbon balance. Furthermore, the evidenced gas discharges provide a unique natural laboratory for

  9. Direct evidence for coastal iodine particles from Laminaria macroalgae – linkage to emissions of molecular iodine

    Directory of Open Access Journals (Sweden)

    G. McFiggans

    2004-01-01

    Full Text Available Renewal of ultrafine aerosols in the marine boundary layer may lead to repopulation of the marine distribution and ultimately determine the concentration of cloud condensation nuclei (CCN. Thus the formation of nanometre-scale particles can lead to enhanced scattering of incoming radiation and a net cooling of the atmosphere. The recent demonstration of the chamber formation of new particles from the photolytic production of condensable iodine-containing compounds from diiodomethane (CH2I2, (O'Dowd et al., 2002; Kolb, 2002; Jimenez et al., 2003a; Burkholder and Ravishankara, 2003, provides an additional mechanism to the gas-to-particle conversion of sulphuric acid formed in the photo-oxidation of dimethylsulphide for marine aerosol repopulation. CH2I2 is emitted from seaweeds (Carpenter et al., 1999, 2000 and has been suggested as an initiator of particle formation. We demonstrate here for the first time that ultrafine iodine-containing particles are produced by intertidal macroalgae exposed to ambient levels of ozone. The particle composition is very similar both to those formed in the chamber photo-oxidation of diiodomethane and in the oxidation of molecular iodine by ozone. The particles formed in all three systems are similarly aspherical. When small, those formed in the molecular iodine system swell only moderately when exposed to increased humidity environments, and swell progressively less with increasing size; this behaviour occurs whether they are formed in dry or humid environments, in contrast to those in the CH2I2 system. Direct coastal boundary layer observations of molecular iodine, ultrafine particle production and iodocarbons are reported. Using a newly measured molecular iodine photolysis rate, it is shown that, if atomic iodine is involved in the observed particle bursts, it is of the order of at least 1000 times more likely to result from molecular iodine photolysis than diiodomethane photolysis. A hypothesis for molecular

  10. A direct evidence for high carbon dioxide and radon-222 discharge in Central Nepal

    International Nuclear Information System (INIS)

    Gas discharges have been identified at the Syabru-Bensi hot springs, located at the front of the High Himalaya in Central Nepal, in the Main Central Thrust zone. The hot spring waters are characterized by a temperature reaching 61 C, high salinity, high alkalinity and δ13C varying from +0. 7 parts per thousand to +4. 8 parts per thousand. The gas is mainly dry carbon dioxide, with a δ13C of -0. 8 parts per thousand. The diffuse carbon dioxide flux, mapped by the accumulation chamber method, reached a value of 19000 g m-2day-1, which is comparable with values measured on active volcanoes. Similar values have been observed over a two-year time interval and the integral around the main gas discharge amounts to 0. 25 ± 0. 07 mol s-1, or 350 ± 100 ton a-1. The mean radon-222 concentration in spring water did not exceed 2. 5 Bq L-1, exponentially decreasing with water temperature. In contrast, in gas bubbles collected in the water or in the dry gas discharges, the radon concentration varied from 16 000 to 41000 Bq m-3. In the soil, radon concentration varied from 25000 to more than 50000 Bq m-3. Radon flux, measured at more than fifty points, reached extreme values, larger than 2 Bq m-2s-1, correlated to the larger values of the carbon dioxide flux. Our direct observation confirms previous studies which indicated large degassing in the Himalaya. The proposed understanding is that carbon dioxide is released at mid-crustal depth by metamorphic reactions within the Indian basement, transported along pre-existing faults by meteoric hot water circulation, and degassed before reaching surface. This work, first, confirms that further studies should be undertaken to better constrain the carbon budget of the Himalaya, and, more generally, the contribution of mountain building to the global carbon balance. Furthermore, the evidenced gas discharges provide a unique natural laboratory for methodological studies, and appear particularly important to study as a function of time

  11. Acute shear stress direction dictates adherent cell remodeling and verifies shear profile of spinning disk assays

    International Nuclear Information System (INIS)

    Several methods have been developed to quantify population level changes in cell attachment strength given its large heterogeneity. One such method is the rotating disk chamber or ‘spinning disk’ in which a range of shear forces are applied to attached cells to quantify detachment force, i.e. attachment strength, which can be heterogeneous within cell populations. However, computing the exact force vectors that act upon cells is complicated by complex flow fields and variable cell morphologies. Recent observations suggest that cells may remodel their morphology and align during acute shear exposure, but contrary to intuition, shear is not orthogonal to the radial direction. Here we theoretically derive the magnitude and direction of applied shear and demonstrate that cells, under certain physiological conditions, align in this direction within minutes. Shear force magnitude is also experimentally verified which validates that for spread cells shear forces and not torque or drag dominate in this assay, and demonstrates that the applied force per cell area is largely independent of initial morphology. These findings suggest that direct quantified comparison of the effects of shear on a wide array of cell types and conditions can be made with confidence using this assay without the need for computational or numerical modeling. (paper)

  12. Calpain-Mediated Positional Information Directs Cell Wall Orientation to Sustain Plant Stem Cell Activity, Growth and Development.

    Science.gov (United States)

    Liang, Zhe; Brown, Roy C; Fletcher, Jennifer C; Opsahl-Sorteberg, Hilde-Gunn

    2015-09-01

    Eukaryotic development and stem cell control depend on the integration of cell positional sensing with cell cycle control and cell wall positioning, yet few factors that directly link these events are known. The DEFECTIVE KERNEL1 (DEK1) gene encoding the unique plant calpain protein is fundamental for development and growth, being essential to confer and maintain epidermal cell identity that allows development beyond the globular embryo stage. We show that DEK1 expression is highest in the actively dividing cells of seeds, meristems and vasculature. We further show that eliminating Arabidopsis DEK1 function leads to changes in developmental cues from the first zygotic division onward, altered microtubule patterns and misshapen cells, resulting in early embryo abortion. Expression of the embryonic marker genes WOX2, ATML1, PIN4, WUS and STM, related to axis organization, cell identity and meristem functions, is also altered in dek1 embryos. By monitoring cell layer-specific DEK1 down-regulation, we show that L1- and 35S-induced down-regulation mainly affects stem cell functions, causing severe shoot apical meristem phenotypes. These results are consistent with a requirement for DEK1 to direct layer-specific cellular activities and set downstream developmental cues. Our data suggest that DEK1 may anchor cell wall positions and control cell division and differentiation, thereby balancing the plant's requirement to maintain totipotent stem cell reservoirs while simultaneously directing growth and organ formation. A role for DEK1 in regulating microtubule-orchestrated cell wall orientation during cell division can explain its effects on embryonic development, and suggests a more general function for calpains in microtubule organization in eukaryotic cells. PMID:26220906

  13. HIV-host interactome revealed directly from infected cells.

    Science.gov (United States)

    Luo, Yang; Jacobs, Erica Y; Greco, Todd M; Mohammed, Kevin D; Tong, Tommy; Keegan, Sarah; Binley, James M; Cristea, Ileana M; Fenyö, David; Rout, Michael P; Chait, Brian T; Muesing, Mark A

    2016-01-01

    Although genetically compact, HIV-1 commandeers vast arrays of cellular machinery to sustain and protect it during cycles of viral outgrowth. Transposon-mediated saturation linker scanning mutagenesis was used to isolate fully replication-competent viruses harbouring a potent foreign epitope tag. Using these viral isolates, we performed differential isotopic labelling and affinity-capture mass spectrometric analyses on samples obtained from cultures of human lymphocytes to classify the vicinal interactomes of the viral Env and Vif proteins as they occur during natural infection. Importantly, interacting proteins were recovered without bias, regardless of their potential for positive, negative or neutral impact on viral replication. We identified specific host associations made with trimerized Env during its biosynthesis, at virological synapses, with innate immune effectors (such as HLA-E) and with certain cellular signalling pathways (for example, Notch1). We also defined Vif associations with host proteins involved in the control of nuclear transcription and nucleoside biosynthesis as well as those interacting stably or transiently with the cytoplasmic protein degradation apparatus. Our approach is broadly applicable to elucidating pathogen-host interactomes, providing high-certainty identification of interactors by their direct access during cycling infection. Understanding the pathophysiological consequences of these associations is likely to provide strategic targets for antiviral intervention. PMID:27572969

  14. Porous carbon as electrode material in direct ethanol fuel cells (DEFCs) synthesized by the direct carbonization of MOF-5

    KAUST Repository

    Khan, Inayatali

    2014-01-12

    Porous carbon (PC-900) was prepared by direct carbonization of porous metal-organic framework (MOF)-5 (Zn4O(bdc)3, bdc=1,4-benzenedicarboxylate) at 900 °C. The carbon material was deposited with PtM (M=Fe, Ni, Co, and Cu (20 %) metal loading) nanoparticles using the polyol reduction method, and catalysts PtM/PC-900 were designed for direct ethanol fuel cells (DEFCs). However, herein, we are reporting PtFe/PC-900 catalyst combination which has exhibited superior performance among other options. This catalyst was characterized by powder XRD, high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and selected area electron diffraction (SAED) technique. The electrocatalytic capability of the catalyst for ethanol electrooxidation was investigated using cyclic voltammetry and direct ethanol single cell testing. The results were compared with those of PtFe and Pt supported on Vulcan XC72 carbon catalysts (PFe/CX-72 and Pt/XC-72) prepared via the same method. It has been observed that the catalyst PtFe/PC-900 developed in this work showed an outstanding normalized activity per gram of Pt (6.8 mA/g Pt) and superior power density (121 mW/cm2 at 90 °C) compared to commercially available carbon-supported catalysts. © Springer-Verlag Berlin Heidelberg 2014.

  15. ERC product improvement activities for direct fuel cell power plants

    Energy Technology Data Exchange (ETDEWEB)

    Bentley, C.; Carlson, G.; Doyon, J. [and others

    1995-08-01

    This program is designed to advance the carbonate fuel cell technology from the current power plant demonstration status to the commercial design in an approximately five-year period. The specific objectives which will allow attainment of the overall program goal are: (1) Define market-responsive power plant requirements and specifications, (2) Establish the design for a multifuel, low-cost, modular, market-responsive power plant, (3) Resolve power plant manufacturing issues and define the design for the commercial manufacturing facility, (4) Define the stack and BOP equipment packaging arrangement and define module designs, (5) Acquire capability to support developmental testing of stacks and BOP equipment as required to prepare for commercial design, and (6) Resolve stack and BOP equipment technology issues and design, build, and field test a modular commercial prototype power plant to demonstrate readiness for commercial entry. A seven-task program, dedicated to attaining objective(s) in the areas noted above, was initiated in December 1994. Accomplishments of the first six months are discussed in this paper.

  16. Direct observation of catch bonds involving cell-adhesion molecules

    Science.gov (United States)

    Marshall, Bryan T.; Long, Mian; Piper, James W.; Yago, Tadayuki; McEver, Rodger P.; Zhu, Cheng

    2003-05-01

    Bonds between adhesion molecules are often mechanically stressed. A striking example is the tensile force applied to selectin-ligand bonds, which mediate the tethering and rolling of flowing leukocytes on vascular surfaces. It has been suggested that force could either shorten bond lifetimes, because work done by the force could lower the energy barrier between the bound and free states (`slip'), or prolong bond lifetimes by deforming the molecules such that they lock more tightly (`catch'). Whereas slip bonds have been widely observed, catch bonds have not been demonstrated experimentally. Here, using atomic force microscopy and flow-chamber experiments, we show that increasing force first prolonged and then shortened the lifetimes of P-selectin complexes with P-selectin glycoprotein ligand-1, revealing both catch and slip bond behaviour. Transitions between catch and slip bonds might explain why leukocyte rolling on selectins first increases and then decreases as wall shear stress increases. This dual response to force provides a mechanism for regulating cell adhesion under conditions of variable mechanical stress.

  17. Highly Durable Direct Methanol Fuel Cell with Double-Layered Catalyst Cathode

    Directory of Open Access Journals (Sweden)

    Jing Liu

    2015-01-01

    Full Text Available Polymer electrolyte membrane (PEM is one of the key components in direct methanol fuel cells. However, the PEM usually gets attacked by reactive oxygen species during the operation period, resulting in the loss of membrane integrity and formation of defects. Herein, a double-layered catalyst cathode electrode consisting of Pt/CeO2-C as inner catalyst and Pt/C as outer catalyst is fabricated to extend the lifetime and minimize the performance loss of DMFC. Although the maximum power density of membrane electrode assembly (MEA with catalyst cathode is slightly lower than that of the traditional one, its durability is significantly improved. No obvious degradation is evident in the MEA with double-layered catalyst cathode within durability testing. These results indicated that Pt/CeO2-C as inner cathode catalyst layer greatly improved the stability of MEA. The significant reason for the improved stability of MEA is the ability of CeO2 to act as free-radical scavengers.

  18. Micropump Fuel Mix Control for Novel Miniature Direct Methanol Fuel Cells Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Energies and Power Densities of Direct Methanol Fuel Cells (DMFCs) are limited by the size and weight associated with the liquid pump, which must circulate the...

  19. Pressure-assisted cell spinning: a direct protocol for spinning biologically viable cell-bearing fibres and scaffolds

    International Nuclear Information System (INIS)

    We recently pioneered the ability to directly electrospin living cells from which scaffolds to membranes were derived. This protocol, now widely referred to as 'cell electrospinning', is currently undergoing in-depth investigations where the post-treated cell's global gene expression to its sub-cellular components is being investigated for understanding any effects post-treating. Our motivation is to develop this method for the biomedical sciences, in particular for applications in regenerative and therapeutic medicine. In the current work, we unveil a direct cell spinning protocol which is non-electric field driven and which will compete directly with cell electrospinning. We referred to this processing method as 'pressure-assisted spinning' in our previous studies, where we demonstrated this route as an emerging micro/nanotechnology. In the current context, we refer to this processing protocol as 'pressure-assisted cell spinning' (PACS). Our developmental studies on PACS reported here show, for the first time, that this technique could be explored as an alternative approach to cell electrospinning. Pressure-assisted cell spinning now enters the direct biological scaffold to membrane formation league

  20. Pressure-assisted cell spinning: a direct protocol for spinning biologically viable cell-bearing fibres and scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Arumuganathar, Sumathy [Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom); Irvine, Scott [Royal Free and University College London Medical School, Rayne Institute, 5 University Street, London WC1E 6JJ (United Kingdom); McEwan, Jean R [Molecular Immunology Unit, Institute of Child Health, University College London, Guilford Street, London WC1N 1EH (United Kingdom); Jayasinghe, Suwan N [Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom)

    2007-12-15

    We recently pioneered the ability to directly electrospin living cells from which scaffolds to membranes were derived. This protocol, now widely referred to as 'cell electrospinning', is currently undergoing in-depth investigations where the post-treated cell's global gene expression to its sub-cellular components is being investigated for understanding any effects post-treating. Our motivation is to develop this method for the biomedical sciences, in particular for applications in regenerative and therapeutic medicine. In the current work, we unveil a direct cell spinning protocol which is non-electric field driven and which will compete directly with cell electrospinning. We referred to this processing method as 'pressure-assisted spinning' in our previous studies, where we demonstrated this route as an emerging micro/nanotechnology. In the current context, we refer to this processing protocol as 'pressure-assisted cell spinning' (PACS). Our developmental studies on PACS reported here show, for the first time, that this technique could be explored as an alternative approach to cell electrospinning. Pressure-assisted cell spinning now enters the direct biological scaffold to membrane formation league.

  1. Plasma treatment of biomaterials to direct the differentiation of embryonic stem cells

    Science.gov (United States)

    Hanley, Erik

    In this work, we explore how embryonic stem (ES) cell differentiation patterns are affected by surface interactions with plasma-processed materials. We hypothesize that mouse embryonic stem-cell exposure to certain plasma-polymerized tetraglyme surfaces will direct their differentiation into endothelial cells. R1 mouse embryonic stem (ES) cells were plated on surfaces onto which tetraglyme was deposited by plasma polymerization. In addition, tissue-treated polystyrene and control glass cover slips were also examined. Some samples were fixed three days after plating and immunofluorescence stained with platelet endothelial-cell adhesion molecule, while the others were fixed seven days after plating and immunofluorescence stained with von Willebrand Factor. Positive results seen by ES cell derivatives precociously expressing the vWF and PECAM genetic markers on the plasma-polymerized tetraglyme treated surfaces suggest that the plasma-polymerized surfaces direct differentiation of ES cells into endothelial cells. Research goals of this dissertation include: characterization of the material properties of the plasma-polymerized tetraglyme surfaces that induce directed differentiation of ES cells into endothelial cells, optimization of the plasma-polymerization process to maximize the number of endothelial cells derived from R1 ES cells, and biological experimentation to characterize properties of the mechanism of directed differentiation. A potential application of this work is in the design and construction of an artificial blood vessel. Current small-scale arterial substitutes have proved inadequate because of thrombogenicity and infection. Moreover, the lower blood flow velocities of smaller vessels pose a different set of design criteria and introduce new problems not encountered in large arterial substitutes. By utilizing a tissue engineering approach that incorporates embryonic stem cell-derived endothelial cells, the longevity of the prosthesis can be ensured.

  2. Directed differentiation of rhesus monkey ES cells into pancreatic cell phenotypes

    OpenAIRE

    Nauert Brian; Andrews Laura; Kuo Hung-Chih; Lester Linda B; Wolf Don P

    2004-01-01

    Abstract Embryonic stem cells (ES) can self-replicate and differentiate into all cell types including insulin-producing, beta-like cells and could, therefore, be used to treat diabetes mellitus. To date, results of stem cell differentiation into beta cells have been debated, largely due to difficulties in defining the identity of a beta cell. We have recently differentiated non-human primate (rhesus) embryonic stem (rES) cell lines into insulin producing, beta-like cells with the beta cell gr...

  3. Both visual and idiothetic cues contribute to head direction cell stability during navigation along complex routes

    OpenAIRE

    Yoder, Ryan M.; Clark, Benjamin J.; Brown, Joel E.; Lamia, Mignon V.; Valerio, Stephane; Shinder, Michael E.; Taube, Jeffrey S.

    2011-01-01

    Successful navigation requires a constantly updated neural representation of directional heading, which is conveyed by head direction (HD) cells. The HD signal is predominantly controlled by visual landmarks, but when familiar landmarks are unavailable, self-motion cues are able to control the HD signal via path integration. Previous studies of the relationship between HD cell activity and path integration have been limited to two or more arenas located in the same room, a drawback for interp...

  4. Ex situ and in situ characterization of Direct Alcohol Fuel Cell anode materials

    OpenAIRE

    Santasalo-Aarnio, Annukka

    2012-01-01

    With direct alcohol fuel cells (DAFC) the chemical energy of the reactants can be directly converted to electrical energy that can be used for instance in portable applications, independent of the electrical network. Liquid fuels such as organic alcohols are interesting for customer applications because they are more facile to use and relatively safe when compared with gaseous hydrogen. However, the obstacles to commercialization are the expensive cell components, catalysts and electrolyte me...

  5. Comparative exergy analysis of direct alcohol fuel cells using fuel mixtures

    OpenAIRE

    Leo Mena, Teresa de Jesus; Raso García, Miguel Ángel; Navarro Arevalo, Emilio; Sánchez de la Blanca, Emilia

    2011-01-01

    Within the last years there has been increasing interest in direct liquid fuel cells as power sources for portable devices and, in the future, power plants for electric vehicles and other transport media as ships will join those applications. Methanol is considerably more convenient and easy to use than gaseous hydrogen and a considerable work is devoted to the development of direct methanol fuel cells. But ethanol has much lower toxicity and from an ecological viewpoint ethanol is exceptiona...

  6. Direct conversion of C. elegans germ cells into specific neuron types

    OpenAIRE

    Tursun, Baris; Patel, Tulsi; Kratsios, Paschalis; Hobert, Oliver

    2010-01-01

    The ability of transcription factors to directly reprogram the identity of cell types is usually restricted and is defined by cellular context. We show here that through ectopic expression of single C. elegans transcription factors, the identity of mitotic germ cells can be directly converted into that of specific neuron types (glutamatergic, cholinergic or GABAergic). This reprogramming event requires the removal of the histone chaperone LIN-53/RbAp48, a component of several histone remodeli...

  7. Binary and ternary palladium based electrocatalysts for alkaline direct glycerol fuel cell

    Science.gov (United States)

    Geraldes, Adriana Napoleão; da Silva, Dionisio Furtunato; e Silva, Leonardo Gondim de Andrade; Spinacé, Estevam Vitório; Neto, Almir Oliveira; dos Santos, Mauro Coelho

    2015-10-01

    Pd/C, PdAu/C 50:50, PdSn/C 50:50, PdAuSn/C 50:40:10 and PdAuSn/C 50:10:40 electrocatalysts are prepared using an electron beam irradiation reduction method and tested for glycerol electro-oxidation in alkaline medium. X-Ray diffraction (XRD), Energy dispersive X-ray analysis (EDX), Transmission electron Microscopy (TEM) and Cyclic Voltammetry (CV) are used to characterize the resulting materials. The activity for glycerol electro-oxidation is tested in alkaline medium at room temperature using Cyclic Voltammetry and Chronoamperometry (CA) and in a single alkaline direct glycerol fuel cell (ADGFC) at temperature range of 60-90 °C. EDX analysis demonstrate that Pd:Au:Sn atomic ratios are very similar to the nominal ones. X-ray diffractograms of PdAuSn/C electrocatalysts evidence the presence of Pd (fcc), Au (fcc) and SnO2 phases. TEM analysis demonstrates a good dispersion of the nanoparticles on the carbon support with some agglomerates. Cyclic Voltammetry experiments suggest that PdAuSn/C electrocatalysts demonstrate better results. In single fuel cell tests, at 85 °C, using 2.0 mol L-1 glycerol in 2.0 mol L-1 KOH solutions, the electrocatalyst PdAuSn/C 50:40:10 demonstrate highest power density (51 mW cm-2) and the 120 h durability tests demonstrate a 210 μV h-1 degradation rate.

  8. Investigation of in vitro bone cell adhesion and proliferation on Ti using direct current stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Bodhak, Subhadip; Bose, Susmita [W. M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164-2920 (United States); Kinsel, William C. [Mechanical Engineering, Washington State University, Tri-Cities, WA (United States); Bandyopadhyay, Amit, E-mail: amitband@wsu.edu [W. M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164-2920 (United States)

    2012-12-01

    Our objective was to establish an in vitro cell culture protocol to improve bone cell attachment and proliferation on Ti substrate using direct current stimulation. For this purpose, a custom made electrical stimulator was developed and a varying range of direct currents, from 5 to 25 {mu}A, was used to study the current stimulation effect on bone cells cultured on conducting Ti samples in vitro. Cell-material interaction was studied for a maximum of 5 days by culturing with human fetal osteoblast cells (hFOB). The direct current was applied in every 8 h time interval and the duration of electrical stimulation was kept constant at 15 min for all cases. In vitro results showed that direct current stimulation significantly favored bone cell attachment and proliferation in comparison to nonstimulated Ti surface. Immunochemistry and confocal microscopy results confirmed that the cell adhesion was most pronounced on 25 {mu}A direct current stimulated Ti surfaces as hFOB cells expressed higher vinculin protein with increasing amount of direct current. Furthermore, MTT assay results established that cells grew 30% higher in number under 25 {mu}A electrical stimulation as compared to nonstimulated Ti surface after 5 days of culture period. In this work we have successfully established a simple and cost effective in vitro protocol offering easy and rapid analysis of bone cell-material interaction which can be used in promotion of bone cell attachment and growth on Ti substrate using direct current electrical stimulation in an in vitro model. - Highlights: Black-Right-Pointing-Pointer D.C. stimulation was used to enhance in vitro bone cell adhesion and proliferation. Black-Right-Pointing-Pointer Cells cultured on Ti were stimulated by using a custom made electrical stimulator. Black-Right-Pointing-Pointer Optimization was performed by using a varying range of direct currents {approx} 5 to 25 {mu}A. Black-Right-Pointing-Pointer 25 {mu}A stimulation was found most beneficial

  9. Computational model of cell positioning: directed and collective migration in the intestinal crypt epithelium

    Science.gov (United States)

    Wong, Shek Yoon; Chiam, K.-H.; Lim, Chwee Teck; Matsudaira, Paul

    2010-01-01

    The epithelium of the intestinal crypt is a dynamic tissue undergoing constant regeneration through cell growth, cell division, cell differentiation and apoptosis. How the epithelial cells maintain correct positioning and how they migrate in a directed and collective fashion are still not well understood. In this paper, we developed a computational model to elucidate these processes. We show that differential adhesion between epithelial cells, caused by the differential activation of EphB receptors and ephrinB ligands along the crypt axis, is necessary to regulate cell positioning. Differential cell adhesion has been proposed previously to guide cell movement and cause cell sorting in biological tissues. The proliferative cells and the differentiated post-mitotic cells do not intermingle as long as differential adhesion is maintained. We also show that, without differential adhesion, Paneth cells are randomly distributed throughout the intestinal crypt. In addition, our model suggests that, with differential adhesion, cells migrate more rapidly as they approach the top of the intestinal crypt. Finally, by calculating the spatial correlation function of the cell velocities, we observe that differential adhesion results in the differentiated epithelial cells moving in a coordinated manner, where correlated velocities are maintained at large distances, suggesting that differential adhesion regulates coordinated migration of cells in tissues. PMID:20356873

  10. DETECTION OF WHITE DWARF COMPANIONS TO BLUE STRAGGLERS IN THE OPEN CLUSTER NGC 188: DIRECT EVIDENCE FOR RECENT MASS TRANSFER

    International Nuclear Information System (INIS)

    Several possible formation pathways for blue straggler stars have been developed recently, but no one pathway has yet been observationally confirmed for a specific blue straggler. Here we report the first findings from a Hubble Space Telescope Advanced Camera for Surveys/Solar Blind Channel far-UV photometric program to search for white dwarf companions to blue straggler stars. We find three hot and young white dwarf companions to blue straggler stars in the 7 Gyr open cluster NGC 188, indicating that mass transfer in these systems ended less than 300 Myr ago. These companions are direct and secure observational evidence that these blue straggler stars were formed through mass transfer in binary stars. Their existence in a well-studied cluster environment allows for observational constraints of both the current binary system and the progenitor binary system, mapping the entire mass transfer history

  11. DETECTION OF WHITE DWARF COMPANIONS TO BLUE STRAGGLERS IN THE OPEN CLUSTER NGC 188: DIRECT EVIDENCE FOR RECENT MASS TRANSFER

    Energy Technology Data Exchange (ETDEWEB)

    Gosnell, Natalie M.; Mathieu, Robert D. [Department of Astronomy, University of Wisconsin - Madison, 475 N. Charter St., Madison, WI 53706 (United States); Geller, Aaron M. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Rd, Evanston, IL 60208 (United States); Sills, Alison [Department of Physics and Astronomy, McMaster University, 1280 Main St. W, Hamilton, ON L8S 4M1 (Canada); Leigh, Nathan [Department of Physics, University of Alberta, CCIS 4-183, Edmonton, AB T6G 2E1 (Canada); Knigge, Christian, E-mail: gosnell@astro.wisc.edu [School of Physics and Astronomy, University of Southampton, Highfield, Southampton, SO17 IBJ (United Kingdom)

    2014-03-01

    Several possible formation pathways for blue straggler stars have been developed recently, but no one pathway has yet been observationally confirmed for a specific blue straggler. Here we report the first findings from a Hubble Space Telescope Advanced Camera for Surveys/Solar Blind Channel far-UV photometric program to search for white dwarf companions to blue straggler stars. We find three hot and young white dwarf companions to blue straggler stars in the 7 Gyr open cluster NGC 188, indicating that mass transfer in these systems ended less than 300 Myr ago. These companions are direct and secure observational evidence that these blue straggler stars were formed through mass transfer in binary stars. Their existence in a well-studied cluster environment allows for observational constraints of both the current binary system and the progenitor binary system, mapping the entire mass transfer history.

  12. Recent progress in stem cell differentiation directed by material and mechanical cues.

    Science.gov (United States)

    Lin, Xunxun; Shi, Yuan; Cao, Yilin; Liu, Wei

    2016-02-01

    Stem cells play essential roles in tissue regeneration in vivo via specific lineage differentiation induced by environmental factors. In the past, biochemical signals were the focus of induced stem cell differentiation. As reported by Engler et al (2006 Cell 126 677-89), biophysical signal mediated stem cell differentiation could also serve as an important inducer. With the advancement of material science, it becomes a possible strategy to generate active biophysical signals for directing stem cell fate through specially designed material microstructures. In the past five years, significant progress has been made in this field, and these designed biophysical signals include material elasticity/rigidity, micropatterned structure, extracellular matrix (ECM) coated materials, material transmitted extracellular mechanical force etc. A large number of investigations involved material directed differentiation of mesenchymal stem cells, neural stem/progenitor cells, adipose derived stem cells, hematopoietic stem/progenitor cells, embryonic stem cells and other cells. Hydrogel based materials were commonly used to create varied mechanical properties via modifying the ratio of different components, crosslinking levels, matrix concentration and conjugation with other components. Among them, polyacrylamide (PAM) and polydimethylsiloxane (PDMS) hydrogels remained the major types of material. Specially designed micropatterning was not only able to create a unique topographical surface to control cell shape, alignment, cell-cell and cell-matrix contact for basic stem cell biology study, but also could be integrated with 3D bioprinting to generate micropattered 3D structure and thus to induce stem cell based tissue regeneration. ECM coating on a specific topographical structure was capable of inducing even more specific and potent stem cell differentiation along with soluble factors and mechanical force. The article overviews the progress of the past five years in this particular

  13. Epigenetic Priming Confers Direct Cell Trans-Differentiation From Adipocyte to Osteoblast in a Transgene-Free State.

    Science.gov (United States)

    Cho, Young-Dan; Bae, Han-Sol; Lee, Dong-Seol; Yoon, Won-Joon; Woo, Kyung-Mi; Baek, Jeong-Hwa; Lee, Gene; Park, Joo-Cheol; Ku, Young; Ryoo, Hyun-Mo

    2016-07-01

    The bone marrow of healthy individuals is primarily composed of osteoblasts and hematopoietic cells, while that of osteoporosis patients has a larger portion of adipocytes. There is evidence that the epigenetic landscape can strongly influence cell differentiation. We have shown that it is possible to direct the trans-differentiation of adipocytes to osteoblasts by modifying the epigenetic landscape with a DNA methyltransferase inhibitor (DNMTi), 5'-aza-dC, followed by Wnt3a treatment to signal osteogenesis. Treating 3T3-L1 adipocytes with 5'-aza-dC induced demethylation in the hypermethylated CpG regions of bone marker genes; subsequent Wnt3a treatment drove the cells to osteogenic differentiation. When old mice with predominantly adipose marrow were treated with both 5'-aza-dC and Wnt3a, decreased fatty tissue and increased bone volume were observed. Together, our results indicate that epigenetic modification permits direct programming of adipocytes into osteoblasts in a mouse model of osteoporosis, suggesting that this approach could be useful in bone tissue-engineering applications. J. Cell. Physiol. 231: 1484-1494, 2016. © 2015 Wiley Periodicals, Inc. PMID:26335354

  14. Direct evidence of an eruptive, filament-hosting magnetic flux rope leading to a fast solar coronal mass ejection

    International Nuclear Information System (INIS)

    Magnetic flux ropes (MFRs) are believed to be at the heart of solar coronal mass ejections (CMEs). A well-known example is the prominence cavity in the low corona that sometimes makes up a three-part white-light (WL) CME upon its eruption. Such a system, which is usually observed in quiet-Sun regions, has long been suggested to be the manifestation of an MFR with relatively cool filament material collecting near its bottom. However, observational evidence of eruptive, filament-hosting MFR systems has been elusive for those originating in active regions. By utilizing multi-passband extreme-ultraviolet (EUV) observations from Solar Dynamics Observatory/Atmospheric Imaging Assembly, we present direct evidence of an eruptive MFR in the low corona that exhibits a hot envelope and a cooler core; the latter is likely the upper part of a filament that undergoes a partial eruption, which is later observed in the upper corona as the coiled kernel of a fast, WL CME. This MFR-like structure exists more than 1 hr prior to its eruption, and displays successive stages of dynamical evolution, in which both ideal and non-ideal physical processes may be involved. The timing of the MFR kinematics is found to be well correlated with the energy release of the associated long-duration C1.9 flare. We suggest that the long-duration flare is the result of prolonged energy release associated with the vertical current sheet induced by the erupting MFR.

  15. Direct Evidence of an Eruptive, Filament-Hosting Magnetic Flux Rope Leading to a Fast Solar Coronal Mass Ejection

    CERN Document Server

    Chen, Bin; Gary, Dale E

    2014-01-01

    Magnetic flux ropes (MFRs) are believed to be at the heart of solar coronal mass ejections (CMEs). A well-known example is the prominence cavity in the low corona that sometimes makes up a three-part white-light CME upon its eruption. Such a system, which is usually observed in quiet-Sun regions, has long been suggested to be the manifestation of an MFR with relatively cool filament material collecting near its bottom. However, observational evidence of eruptive, filament-hosting MFR systems has been elusive for those originating in active regions. By utilizing multi-passband extreme-ultra-violet (EUV) observations from SDO/AIA, we present direct evidence of an eruptive MFR in the low corona that exhibits a hot envelope and a cooler core; the latter is likely the upper part of a filament that undergoes a partial eruption, which is later observed in the upper corona as the coiled kernel of a fast, white-light CME. This MFR-like structure exists more than one hour prior to its eruption, and displays successive ...

  16. Judging Normality and Attractiveness in Faces: Direct Evidence of a More Refined Representation for Own-Race, Young Adult Faces.

    Science.gov (United States)

    Zhou, Xiaomei; Short, Lindsey A; Chan, Harmonie S J; Mondloch, Catherine J

    2016-09-01

    Young and older adults are more sensitive to deviations from normality in young than older adult faces, suggesting that the dimensions of face space are optimized for young adult faces. Here, we extend these findings to own-race faces and provide converging evidence using an attractiveness rating task. In Experiment 1, Caucasian and Chinese adults were shown own- and other-race face pairs; one member was undistorted and the other had compressed or expanded features. Participants indicated which member of each pair was more normal (a task that requires referencing a norm) and which was more expanded (a task that simply requires discrimination). Participants showed an own-race advantage in the normality task but not the discrimination task. In Experiment 2, participants rated the facial attractiveness of own- and other-race faces (Experiment 2a) or young and older adult faces (Experiment 2b). Between-rater variability in ratings of individual faces was higher for other-race and older adult faces; reduced consensus in attractiveness judgments reflects a less refined face space. Collectively, these results provide direct evidence that the dimensions of face space are optimized for own-race and young adult faces, which may underlie face race- and age-based deficits in recognition. PMID:27335127

  17. Direct evidence of an eruptive, filament-hosting magnetic flux rope leading to a fast solar coronal mass ejection

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Bin; Gary, D. E. [Center for Solar-Terrestrial Research, New Jersey Institute of Technology, Newark, NJ 07102 (United States); Bastian, T. S., E-mail: bin.chen@cfa.harvard.edu [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States)

    2014-10-20

    Magnetic flux ropes (MFRs) are believed to be at the heart of solar coronal mass ejections (CMEs). A well-known example is the prominence cavity in the low corona that sometimes makes up a three-part white-light (WL) CME upon its eruption. Such a system, which is usually observed in quiet-Sun regions, has long been suggested to be the manifestation of an MFR with relatively cool filament material collecting near its bottom. However, observational evidence of eruptive, filament-hosting MFR systems has been elusive for those originating in active regions. By utilizing multi-passband extreme-ultraviolet (EUV) observations from Solar Dynamics Observatory/Atmospheric Imaging Assembly, we present direct evidence of an eruptive MFR in the low corona that exhibits a hot envelope and a cooler core; the latter is likely the upper part of a filament that undergoes a partial eruption, which is later observed in the upper corona as the coiled kernel of a fast, WL CME. This MFR-like structure exists more than 1 hr prior to its eruption, and displays successive stages of dynamical evolution, in which both ideal and non-ideal physical processes may be involved. The timing of the MFR kinematics is found to be well correlated with the energy release of the associated long-duration C1.9 flare. We suggest that the long-duration flare is the result of prolonged energy release associated with the vertical current sheet induced by the erupting MFR.

  18. Directed differentiation of rhesus monkey ES cells into pancreatic cell phenotypes

    Directory of Open Access Journals (Sweden)

    Nauert Brian

    2004-06-01

    Full Text Available Abstract Embryonic stem cells (ES can self-replicate and differentiate into all cell types including insulin-producing, beta-like cells and could, therefore, be used to treat diabetes mellitus. To date, results of stem cell differentiation into beta cells have been debated, largely due to difficulties in defining the identity of a beta cell. We have recently differentiated non-human primate (rhesus embryonic stem (rES cell lines into insulin producing, beta-like cells with the beta cell growth factor, Exendin-4 and using C-peptide as a phenotype marker. Cell development was characterized at each stage by gene and protein expression. Insulin, NKX6.1 and glucagon mRNA were expressed in stage 4 cells but not in early undifferentiated cells. We concluded that rES cells could be differentiated ex vivo to insulin producing cells. These differentiated rES cells could be used to develop a non-human primate model for evaluating cell therapy to treat diabetes. To facilitate the identification of beta-like cells and to track the cells post-transplantation, we have developed a marker gene construct: fusing the human insulin promoter (HIP to the green fluorescent protein (GFP gene. This construct was transfected into stage 3 rES derived cells and subsequent GFP expression was identified in C-peptide positive cells, thereby substantiating endogenous insulin production by rES derived cells. Using this GFP detection system, we will enrich our population of insulin producing rES derived cells and track these cells post-transplantation in the non-human primate model.

  19. Challenges in Design of an Orientation free Micro Direct Methanol Fuel Cell (µDMFC)

    DEFF Research Database (Denmark)

    Omidvarnia, Farzaneh; Hansen, Hans Nørgaard; Hales, Jan Harry

    2014-01-01

    challenges in design and manufacturing of a micro direct methanol fuel cell (μDMFC) as the power generator in hearing aid devices is investigated. Among the different challenges in design for μDMFC, the CO2 bubble management and orientation independency of the cell are addressed by proposing a spring loaded...

  20. Effect of CeO2 Infiltration on Hybrid Direct Carbon Fuel Cell Performance

    DEFF Research Database (Denmark)

    Ippolito, Davide; Deleebeeck, Lisa; Kammer Hansen, Kent

    2014-01-01

    The effect of CeO2 infiltration into the anode or CeO2 mixed with the carbon-fuel on the performance of a Hybrid Direct Carbon Fuel Cell (HDCFC) was studied through the use of polarization curves and electrochemical impedance spectroscopy. The use CeO2 in both ways helped to increase the cell...

  1. Superparamagnetic iron oxide nanoparticles for direct labeling of stem cells and in vivo MRI tracking.

    Science.gov (United States)

    Kim, Saejeong J; Lewis, Bobbi; Steiner, Mark-Steven; Bissa, Ursula V; Dose, Christian; Frank, Joseph A

    2016-01-01

    To develop effective stem cell therapies, it is important to track therapeutic cells non-invasively and monitor homing to areas of pathology. The purpose of this study was to design and evaluate the labeling efficiency of commercially available dextran-coated superparamagnetic iron oxide nanoparticles, FeraTrack Direct (FTD), in various stem and immune cells; assess the cytotoxicity and tolerability of the FTD in stem cells; and monitor stem cell homing using FTD-labeled bone-marrow-derived mesenchymal stromal cells (BMSCs) and neural stem cells (NSCs) in a tumor model by in vivo MRI. BMSCs, NSCs, hematopoietic stem cells (HSCs), T-lymphocytes, and monocytes were labeled effectively with FTD without the need for transfection agents, and Prussian blue (PB) staining and transmission electron microscopy (TEM) confirmed intracellular uptake of the agent. The viability, proliferation, and functionality of the labeled cells were minimally or not affected after labeling. When 10(6) FTD-labeled BMSCs or NSCs were injected into C6 glioma bearing nude mice, the cells homing to the tumors were detected as hypointense regions within the tumor using 3 T clinical MRI up to 10 days post injection. Histological analysis confirmed the homing of injected cells to the tumor by the presence of PB positive cells that are not macrophages. Labeling of stem cells or immune cells with FTD was non-toxic, and should facilitate the translation of this agent to clinical trials for evaluation of trafficking of cells by MRI. PMID:26234504

  2. New evidence for the origin of intracranial germ cell tumours from primordial germ cells

    DEFF Research Database (Denmark)

    Hoei-Hansen, C E; Sehested, A; Juhler, M;

    2006-01-01

    , suggesting that it is not required for the initiation of malignant germ cell transformation. The expression of genes associated with embryonic stem cell pluripotency in CNS germ cell tumours strongly suggests that these tumours are derived from cells that retain, at least partially, an embryonic stem cell...... germ cell tumours and analysed expression of a wide panel of stem cell-related proteins (C-KIT, OCT-3/4 (POU5F1), AP-2gamma (TFAP2C), and NANOG) and developmentally regulated germ cell-specific proteins (including MAGE-A4, NY-ESO-1, and TSPY). Expression at the protein level was analysed in 21 children...... and young adults with intracranial germinomas and non-germinomas, contributing to a careful description of these unusual tumours and adding to the understanding of pathogenesis. Stem cell related proteins were highly expressed in intracranial germ cell tumours, and many similarities were detected with...

  3. Stiff Load Cell With High Overload Capability and Direct Frequency Output

    OpenAIRE

    Yan, T.; Jones, B E; Rakowski, R.T.; Tudor, M J; Beeby, S. P.; White, N.M.

    2004-01-01

    This paper reports on the design, construction and characteristics of a novel load cell having stiffness and potential overload capability some 10 times that of a resistive strain gauge load cell. The experimental cell loaded up to 600 kg gives a direct output frequency change of 870 Hz (safety factor of 5). It uses recently developed metallic triple beam resonators with thick-film PZT drives and pickups.

  4. Increasing Fuel Efficiency of Direct Methanol Fuel Cell Systems with Feedforward Control of the Operating Concentration

    OpenAIRE

    Youngseung Na; Federico Zenith; Ulrike Krewer

    2015-01-01

    Most of the R&D on fuel cells for portable applications concentrates on increasing efficiencies and energy densities to compete with other energy storage devices, especially batteries. To improve the efficiency of direct methanol fuel cell (DMFC) systems, several modifications to system layouts and operating strategies are considered in this paper, rather than modifications to the fuel cell itself. Two modified DMFC systems are presented, one with an additional inline mixer and a further ...

  5. The spatial and time evidence for the excess of multihadron events in the direction of Cygnus X-3

    International Nuclear Information System (INIS)

    The results of the search for the signal of hadron groups correlated with Cygnus X-3 using data of the PION experiment from February to August 1985 have been reported. It has been revealed the enhancement in the statistical significance of the observed excess with increasing both the size of the cell centred in the direction of Cyg X-3 and the number of hadrons in the group. The statistical significance of the excess achieves a maximum value (≅7σ) in a 30 degx30 deg cell for groups with the number of hadrons n≥6. The phase analysis with the 4.8-h orbital period revealed the presence of a peak in the phase interval 0.3-0.4 for hadron groups with n≥6. The fluxes of multihadron events in the direction of Cygnus X-3 are comparable to the fluxes of high-energy muons detected in the two underground experiments, Soudan-1 and NUSEX. 31 refs.; 5 figs.; 1 tab

  6. Hybrid Direct Carbon Fuel Cell Performance with Anode Current Collector Material

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Kammer Hansen, Kent

    2015-01-01

    The influence of the current collector on the performance of a hybrid direct carbon fuel cell (HDCFC), consisting of solid oxide fuel cell (SOFC) with a molten carbonate-carbon slurry in contact with the anode, has been investigated using current-voltage curves. Four different anode current...... collectors were studied: Au, Ni, Ag, and Pt. It was shown that the performance of the direct carbon fuel cell (DCFC) is dependent on the current collector materials, Ni and Pt giving the best performance, due to their catalytic activity. Gold is suggested to be the best material as an inert current collector...

  7. Direct elemental analysis of cancer cell lines by total reflection X-ray fluorescence

    International Nuclear Information System (INIS)

    The elemental content of Cu, Fe and Zn in two human adenocarcinoma cell lines was investigated by total reflection X-ray fluorescence (TXRF) spectrometry. Cancer cells were sedimented directly to the quartz plates using a modified cytospin slide holder setup. Special glass stands and caps were also constructed to hold the quartz plates with the cells during the vapour-phase microwave assisted digestion. The method was validated by analysis of certified reference materials. The signal-to-noise ratio was optimized by washing the cells with different solutions. The technique was applied to the determination of Cu, Fe and Zn content of HT-29 and HCA-7 colorectal adenocarcinoma cell lines. Dry mass of the centrifuged cells were determined and the elemental analysis data reported for the two cell lines were referred either to cell numbers, to the total protein content or to the dry mass

  8. Weekly periodicities of aerosol optical thickness over Central Europe – evidence of an anthropogenic direct aerosol effect

    Directory of Open Access Journals (Sweden)

    B. Vogel

    2007-08-01

    Full Text Available Statistical analyses of data from 14 ground-based sun photometer stations all over Central Europe are presented. All stations are part of the Aerosol Robotic Network (AERONET, and only data of the highest data quality level 2.0 had been applied. The averages by weekday of aerosol optical thickness (AOT at a wavelength of 440 nm of 12 of the 14 stations show a weekly periodicity with lowest values on Sunday and Monday, but greatest values from Wednesday until Saturday, that is significant at least on a 90% level. The stations in Germany and in Greater Paris show weekly cycles with ranges of about 20% on average. In Northern Italy and Switzerland this range is about 10% on average. The corresponding weekly cycle of anthropogenic gaseous and particulate emissions leads us to the conclusion of the anthropogenic origin of the weekly AOT cycle. Since these AOT patterns are derived from the reduction of the direct sun radiation by the columnar atmospheric aerosol, this result represents strong evidence for an anthropogenic direct aerosol effect on shortwave radiation. Furthermore, this study makes a first contribution to the understanding and explanation of recently observed weekly periodicities in meteorological variables as temperature in Germany.

  9. The German model of capitalism and the persistence of outward foreign direct investment: evidence from German manufacturing industries

    Directory of Open Access Journals (Sweden)

    Martin T Bohl

    2011-06-01

    Full Text Available Against the backdrop of critique on the German model of capitalism in general, and German public policy in particular as to the ability to successfully adjust to rapid change and exogenous shocks in wake of economic globalisation, this paper investigates the degree of shock persistence in foreign direct investment (FDI of ten German manufacturing industries for the period 1976 to 2003. Theory on exports and non-FDI investment suggests that FDI should exhibit a considerable degree of shock persistence because they are subject to high sunk costs because of high entry and exit costs associated with the high level of asset specificity that is normally connected to FDI. Persistence in foreign direct investment time series data is established by applying various unit root tests. The results are robust to the potential presence of structural breaks in the data. The empirical analysis shows that German outward FDI in mature manufacturing industries, with one exception, exhibits a high degree of shock persistence. The results suggest, at least for mature German industries, that the sunk costs view on shock persistency is confirmed for outward FDI. The results furnish evidence for a tentative assessment of the relationship between German public policy and FDI strategies of multinational firms.

  10. Directional memory arises from long-lived cytoskeletal asymmetries in polarized chemotactic cells.

    Science.gov (United States)

    Prentice-Mott, Harrison V; Meroz, Yasmine; Carlson, Andreas; Levine, Michael A; Davidson, Michael W; Irimia, Daniel; Charras, Guillaume T; Mahadevan, L; Shah, Jagesh V

    2016-02-01

    Chemotaxis, the directional migration of cells in a chemical gradient, is robust to fluctuations associated with low chemical concentrations and dynamically changing gradients as well as high saturating chemical concentrations. Although a number of reports have identified cellular behavior consistent with a directional memory that could account for behavior in these complex environments, the quantitative and molecular details of such a memory process remain unknown. Using microfluidics to confine cellular motion to a 1D channel and control chemoattractant exposure, we observed directional memory in chemotactic neutrophil-like cells. We modeled this directional memory as a long-lived intracellular asymmetry that decays slower than observed membrane phospholipid signaling. Measurements of intracellular dynamics revealed that moesin at the cell rear is a long-lived element that when inhibited, results in a reduction of memory. Inhibition of ROCK (Rho-associated protein kinase), downstream of RhoA (Ras homolog gene family, member A), stabilized moesin and directional memory while depolymerization of microtubules (MTs) disoriented moesin deposition and also reduced directional memory. Our study reveals that long-lived polarized cytoskeletal structures, specifically moesin, actomyosin, and MTs, provide a directional memory in neutrophil-like cells even as they respond on short time scales to external chemical cues. PMID:26764383

  11. Study of catalysis for solid oxide fuel cells and direct methanol fuel cells

    Science.gov (United States)

    Jiang, Xirong

    Fuel cells offer the enticing promise of cleaner electricity with lower environmental impact than traditional energy conversion technologies. Driven by the interest in power sources for portable electronics, and distributed generation and automotive propulsion markets, active development efforts in the technologies of both solid oxide fuel cell (SOFC) and direct methanol fuel cell (DMFC) devices have achieved significant progress. However, current catalysts for fuel cells are either of low catalytic activity or extremely expensive, presenting a key barrier toward the widespread commercialization of fuel cell devices. In this thesis work, atomic layer deposition (ALD), a novel thin film deposition technique, was employed to apply catalytic Pt to SOFC, and investigate both Pt skin catalysts and Pt-Ru catalysts for methanol oxidation, a very important reaction for DMFC, to increase the activity and utilization levels of the catalysts while simultaneously reducing the catalyst loading. For SOFCs, we explored the use of ALD for the fabrication of electrode components, including an ultra-thin Pt film for use as the electrocatalyst, and a Pt mesh structure for a current collector for SOFCs, aiming for precise control over the catalyst loading and catalyst geometry, and enhancement in the current collect efficiency. We choose Pt since it has high chemical stability and excellent catalytic activity for the O2 reduction reaction and the H2 oxidation reaction even at low operating temperatures. Working SOFC fuel cells were fabricated with ALD-deposited Pt thin films as an electrode/catalyst layer. The measured fuel cell performance reveals that comparable peak power densities were achieved for ALD-deposited Pt anodes with only one-fifth of the Pt loading relative to a DC-sputtered counterpart. In addition to the continuous electrocatalyst layer, a micro-patterned Pt structure was developed via the technique of area selective ALD. By coating yttria-stabilized zirconia, a

  12. Evidence against direct involvement of phosphorylation in the activation of carnitine palmitoyltransferase by okadaic acid in rat hepatocytes.

    Science.gov (United States)

    Guzman, M; Kolodziej, M P; Caldwell, A; Corstorphine, C G; Zammit, V A

    1994-01-01

    The mechanism of activation of mitochondrial overt carnitine palmitoyltransferase (CPT I) by treatment of hepatocytes with okadaic acid (OA) was investigated. Activation was observed when cells were permeabilized with digitonin, but not when a total membrane fraction was obtained by sonication. Both cell disruption methods preserved the activation of phosphorylase observed in OA-treated hepatocytes. Activation of CPT I was also observed in crude homogenates of OA-treated hepatocytes, but it was lost upon subsequent isolation of mitochondria from such homogenates. In all experiments, any activation observed did not depend on the presence or absence of fluoride ions in the permeabilization/homogenization media. When hepatocytes were permeabilized in the absence of fluoride and further incubated with exogenous phosphatases 1 and 2A, the OA-induced activation of CPT was not reversed, whereas the activation of glycogen phosphorylase in the same cells was rapidly reversed. Treatment of hepatocytes with OA, followed by permeabilization and incubation before assay of CPT I, demonstrated that OA had no short-term effect on the sensitivity of CPT I to malonyl-CoA, although the difference in sensitivity between cells isolated from fed and starved rats was fully preserved. Incubation of isolated mitochondria or purified mitochondrial outer membranes with cyclic AMP-dependent or AMP-activated protein kinases, under phosphorylating conditions, did not affect the activity of CPT I or its sensitivity to malonyl-CoA inhibition. Under the same conditions, the use of [32P]ATP resulted in the labelling of several outer-membrane proteins but, unlike [3H]etomoxir-labelled CPT I, none of them was specifically removed from membrane extracts by a specific polyclonal antibody to the enzyme. We conclude that the increase in overt CPT activity observed in permeabilized hepatocytes is not due to direct phosphorylation of CPT I, but may involve interactions between the mitochondrial outer

  13. The Degradation Interface of Magnesium Based Alloys in Direct Contact with Human Primary Osteoblast Cells.

    Directory of Open Access Journals (Sweden)

    Nezha Ahmad Agha

    Full Text Available Magnesium alloys have been identified as a new generation material of orthopaedic implants. In vitro setups mimicking physiological conditions are promising for material / degradation analysis prior to in vivo studies however the direct influence of cell on the degradation mechanism has never been investigated. For the first time, the direct, active, influence of human primary osteoblasts on magnesium-based materials (pure magnesium, Mg-2Ag and Mg-10Gd alloys is studied for up to 14 days. Several parameters such as composition of the degradation interface (directly beneath the cells are analysed with a scanning electron microscope equipped with energy dispersive X-ray and focused ion beam. Furthermore, influence of the materials on cell metabolism is examined via different parameters like active mineralisation process. The results are highlighting the influences of the selected alloying element on the initial cells metabolic activity.

  14. Attenuation of natural killer cell functions by capsaicin through a direct and TRPV1-independent mechanism.

    Science.gov (United States)

    Kim, Hun Sik; Kwon, Hyung-Joon; Kim, Gye Eun; Cho, Mi-Hyang; Yoon, Seung-Yong; Davies, Alexander J; Oh, Seog Bae; Lee, Heuiran; Cho, Young Keol; Joo, Chul Hyun; Kwon, Seog Woon; Kim, Sun Chang; Kim, Yoo Kyum

    2014-07-01

    The assessment of the biological activity of capsaicin, the compound responsible for the spicy flavor of chili pepper, produced controversial results, showing either carcinogenicity or cancer prevention. The innate immune system plays a pivotal role in cancer pathology and prevention; yet, the effect of capsaicin on natural killer (NK) cells, which function in cancer surveillance, is unclear. This study found that capsaicin inhibited NK cell-mediated cytotoxicity and cytokine production (interferon-γ and tumor necrosis factor-α). Capsaicin impaired the cytotoxicity of NK cells, thereby inhibiting lysis of standard target cells and gastric cancer cells by modulating calcium mobilization in NK cells. Capsaicin also induced apoptosis in gastric cancer cells, but that effect required higher concentrations and longer exposure times than those required to trigger NK cell dysfunction. Furthermore, capsaicin inhibited the cytotoxicity of isolated NK cells and of an NK cell line, suggesting a direct effect on NK cells. Antagonists of transient receptor potential vanilloid subfamily member 1 (TRPV1), a cognate capsaicin receptor, or deficiency in TRPV1 expression failed to prevent the defects induced by capsaicin in NK cells expressing functional TRPV1. Thus, the mechanism of action of capsaicin on NK cells is largely independent of TRPV1. Taken together, capsaicin may have chemotherapeutic potential but may impair NK cell function, which plays a central role in tumor surveillance. PMID:24743513

  15. Tumorigenic fragments of APC cause dominant defects in directional cell migration in multiple model systems

    Directory of Open Access Journals (Sweden)

    Scott A. Nelson

    2012-11-01

    Nonsense mutations that result in the expression of truncated, N-terminal, fragments of the adenomatous polyposis coli (APC tumour suppressor protein are found in most sporadic and some hereditary colorectal cancers. These mutations can cause tumorigenesis by eliminating β-catenin-binding sites from APC, which leads to upregulation of β-catenin and thereby results in the induction of oncogenes such as MYC. Here we show that, in three distinct experimental model systems, expression of an N-terminal fragment of APC (N-APC results in loss of directionality, but not speed, of cell motility independently of changes in β-catenin regulation. We developed a system to culture and fluorescently label live pieces of gut tissue to record high-resolution three-dimensional time-lapse movies of cells in situ. This revealed an unexpected complexity of normal gut cell migration, a key process in gut epithelial maintenance, with cells moving with spatial and temporal discontinuity. Quantitative comparison of gut tissue from wild-type mice and APC heterozygotes (APCMin/+; multiple intestinal neoplasia model demonstrated that cells in precancerous epithelia lack directional preference when moving along the crypt-villus axis. This effect was reproduced in diverse experimental systems: in developing chicken embryos, mesoderm cells expressing N-APC failed to migrate normally; in amoeboid Dictyostelium, which lack endogenous APC, expressing an N-APC fragment maintained cell motility, but the cells failed to perform directional chemotaxis; and multicellular Dictyostelium slug aggregates similarly failed to perform phototaxis. We propose that N-terminal fragments of APC represent a gain-of-function mutation that causes cells within tissue to fail to migrate directionally in response to relevant guidance cues. Consistent with this idea, crypts in histologically normal tissues of APCMin/+ intestines are overpopulated with cells, suggesting that a lack of migration might cause cell

  16. Ultrastructural Evidence of Exosome Secretion by Progenitor Cells in Adult Mouse Myocardium and Adult Human Cardiospheres

    Directory of Open Access Journals (Sweden)

    Lucio Barile

    2012-01-01

    Full Text Available The demonstration of beneficial effects of cell therapy despite the persistence of only few transplanted cells in vivo suggests secreted factors may be the active component of this treatment. This so-called paracrine hypothesis is supported by observations that culture media conditioned by progenitor cells contain growth factors that mediate proangiogenic and cytoprotective effects. Cardiac progenitor cells in semi-suspension culture form spherical clusters (cardiospheres that deliver paracrine signals to neighboring cells. A key component of paracrine secretion is exosomes, membrane vesicles that are stored intracellularly in endosomal compartments and are secreted when these structures fuse with the cell plasma membrane. Exosomes have been identified as the active component of proangiogenic effects of bone marrow CD34+ stem cells in mice and the regenerative effects of embryonic mesenchymal stem cells in infarcted hearts in pigs and mice. Here, we provide electron microscopic evidence of exosome secretion by progenitor cells in mouse myocardium and human cardiospheres. Exosomes are emerging as an attractive vector of paracrine signals delivered by progenitor cells. They can be stored as an “off-the-shelf” product. As such, exosomes have the potential for circumventing many of the limitations of viable cells for therapeutic applications in regenerative medicine.

  17. Direct hepatic differentiation of mouse embryonic stem cells induced by valproic acid and cytokines

    Institute of Scientific and Technical Information of China (English)

    Xue-Jun Dong; Guo-Rong Zhang; Qing-Jun Zhou; Ruo-Lang Pan; Ye Chen; Li-Xin Xiang; Jian-Zhong Shao

    2009-01-01

    AIM: To develop a protocol for direct hepatic lineage differentiation from early developmental progenitors to a population of mature hepatocytes. METHODS: Hepatic progenitor cells and then mature hepatocytes from mouse embryonic stem (ES) cells were obtained in a sequential manner, induced by valproic acid (VPA) and cytokines (hepatocyte growth factor, epidermal growth factor and insulin). Morphological changes of the differentiated cells were examined by phase-contrast microscopy and electron microscopy. Reverse transcription polymerase chain reaction and immunocytochemical analyses were used to evaluate the gene expression profiles of the VPA-induced hepatic progenitors and the hepatic progenitor-derived hepatocytes. Glycogen storage, cytochrome P450 activity, transplantation assay, differentiation of bile duct-like structures and tumorigenic analyses were performed for the functional identification of the differentiated cells. Furthermore, FACS and electron microscopy were used for the analyses of cell cycle profile and apoptosis in VPA-induced hepatic differentiated cells. RESULTS: Based on the combination of VPA and cytokines, mouse ES cells differentiated into a uniform and homogeneous cell population of hepatic progenitor cells and then matured into functional hepatocytes. The progenitor population shared several characteristics with ES cells and hepatic stem/progenitor cells, and represented a novel progenitor cell between ES and hepatic oval cells in embryonic development. The differentiated hepatocytes from progenitor cells shared typical characteristics with mature hepatocytes, including the patterns of gene expression, immunological markers, in vitro hepatocyte functions and in vivo capacity to restore acute-damaged liver function. In addition, the differentiation of hepatic progenitor cells from ES cells was accompanied by significant cell cycle arrest and selective survival of differentiating cells towards hepatic lineages. CONCLUSION: Hepatic cells

  18. Direct Image-Based Enumeration of Clostridium phytofermentans Cells on Insoluble Plant Biomass Growth Substrates.

    Science.gov (United States)

    Alvelo-Maurosa, Jesús G; Lee, Scott J; Hazen, Samuel P; Leschine, Susan B

    2016-02-01

    A dual-fluorescent-dye protocol to visualize and quantify Clostridium phytofermentans ISDg (ATCC 700394) cells growing on insoluble cellulosic substrates was developed by combining calcofluor white staining of the growth substrate with cell staining using the nucleic acid dye Syto 9. Cell growth, cell substrate attachment, and fermentation product formation were investigated in cultures containing either Whatman no. 1 filter paper, wild-type Sorghum bicolor, or a reduced-lignin S. bicolor double mutant (bmr-6 bmr-12 double mutant) as the growth substrate. After 3 days of growth, cell numbers in cultures grown on filter paper as the substrate were 6.0- and 2.2-fold higher than cell numbers in cultures with wild-type sorghum and double mutant sorghum, respectively. However, cells produced more ethanol per cell when grown with either sorghum substrate than with filter paper as the substrate. Ethanol yields of cultures were significantly higher with double mutant sorghum than with wild-type sorghum or filter paper as the substrate. Moreover, ethanol production correlated with cell attachment in sorghum cultures: 90% of cells were directly attached to the double mutant sorghum substrate, while only 76% of cells were attached to wild-type sorghum substrate. With filter paper as the growth substrate, ethanol production was correlated with cell number; however, with either wild-type or mutant sorghum, ethanol production did not correlate with cell number, suggesting that only a portion of the microbial cell population was active during growth on sorghum. The dual-staining procedure described here may be used to visualize and enumerate cells directly on insoluble cellulosic substrates, enabling in-depth studies of interactions of microbes with plant biomass. PMID:26637592

  19. High-performance liquid-catalyst fuel cell for direct biomass-into-electricity conversion.

    Science.gov (United States)

    Liu, Wei; Mu, Wei; Deng, Yulin

    2014-12-01

    Herein, we report high-performance fuel cells that are catalyzed solely by polyoxometalate (POM) solution without any solid metal or metal oxide. The novel design of the liquid-catalyst fuel cells (LCFC) changes the traditional gas-solid-surface heterogeneous reactions to liquid-catalysis reactions. With this design, raw biomasses, such as cellulose, starch, and even grass or wood powders can be directly converted into electricity. The power densities of the fuel cell with switchgrass (dry powder) and bush allamanda (freshly collected) are 44 mW cm(-2) and 51 mW cm(-2) respectively. For the cellulose-based biomass fuel cell, the power density is almost 3000 times higher than that of cellulose-based microbial fuel cells. Unlike noble-metal catalysts, POMs are tolerant to most organic and inorganic contaminants. Therefore, almost any raw biomass can be used directly to produce electricity without prior purification. PMID:25283435

  20. Aminopeptidase N is directly sorted to the apical domain in MDCK cells

    DEFF Research Database (Denmark)

    Wessels, H P; Hansen, Gert Helge; Fuhrer, C; Look, A T; Sjöström, H; Norén, Ove; Spiess, M

    In different epithelial cell types, integral membrane proteins appear to follow different sorting pathways to the apical surface. In hepatocytes, several apical proteins were shown to be transported there indirectly via the basolateral membrane, whereas in MDCK cells a direct sorting pathway from...... the trans-Golgi-network to the apical membrane has been demonstrated. However, different proteins had been studied in these cells. To compare the sorting of a single protein in both systems, we have expressed aminopeptidase N, which already had been shown to be sorted indirectly in hepatocytes, in...... transfected MDCK cells. As expected, it was predominantly localized to the apical domain of the plasma membrane. By monitoring the appearance of newly synthesized aminopeptidase N at the apical and basolateral surface, it was found to be directly sorted to the apical domain in MDCK cells, indicating that the...

  1. Evidence for heterophilic adhesion of embryonic retinal cells and neuroblastoma cells to substratum-adsorbed NCAM

    OpenAIRE

    1992-01-01

    The adhesion of embryonic chicken retinal cells and mouse N2A neuroblastoma cells to purified embryonic chicken retinal NCAM adsorbed on a solid substratum was examined using a quantitative centrifugal adhesion assay. Both cell types adhered to NCAM and the adhesion was specifically inhibited by monovalent anti-NCAM antibody fragments. N2A cell adhesion depended on the amount of NCAM applied to the substratum, was cation independent, and was insensitive to treatment with the cytoskeletal pert...

  2. Type III TGFβ receptor and Src direct hyaluronan-mediated invasive cell motility.

    Science.gov (United States)

    Allison, Patrick; Espiritu, Daniella; Barnett, Joey V; Camenisch, Todd D

    2015-03-01

    During embryogenesis, the epicardium undergoes proliferation, migration, and differentiation into several cardiac cell types which contribute to the coronary vessels. This process requires epithelial to mesenchymal transition (EMT) and directed cellular invasion. The Type III Transforming Growth Factor-beta Receptor (TGFβR3) is required for epicardial cell invasion and coronary vessel development. Using primary epicardial cells derived from Tgfbr3(+/+) and Tgfbr3(-/-) mouse embryos, high-molecular weight hyaluronan (HMWHA) stimulated cellular invasion and filamentous (f-actin) polymerization are detected in Tgfbr3(+/+) cells, but not in Tgfbr3(-/-) cells. Furthermore, HMWHA-stimulated cellular invasion and f-actin polymerization in Tgfbr3(+/+) epicardial cells are dependent on Src kinase. Src activation in HMWHA-stimulated Tgfbr3(-/-) epicardial cells is not detected in response to HMWHA. RhoA and Rac1 also fail to activate in response to HMWHA in Tgfbr3(-/-) cells. These events coincide with defective f-actin formation and deficient cellular invasion. Finally, a T841A activating substitution in TGFβR3 drives ligand-independent Src activation. Collectively, these data define a TGFβR3-Src-RhoA/Rac1 pathway that is essential for hyaluronan-directed cell invasion in epicardial cells. PMID:25499979

  3. Ikaros and Aiolos Inhibit Pre-B-Cell Proliferation by Directly Suppressing c-Myc Expression▿

    OpenAIRE

    Ma, Shibin; Pathak, Simanta; Mandal, Malay; Trinh, Long; Clark, Marcus R.; Lu, Runqing

    2010-01-01

    Pre-B-cell expansion is driven by signals from the interleukin-7 receptor and the pre-B-cell receptor and is dependent on cyclin D3 and c-Myc. We have shown previously that interferon regulatory factors 4 and 8 induce the expression of Ikaros and Aiolos to suppress pre-B-cell proliferation. However, the molecular mechanisms through which Ikaros and Aiolos exert their growth inhibitory effect remain to be determined. Here, we provide evidence that Aiolos and Ikaros bind to the c-Myc promoter i...

  4. Apoptotic cells are cleared by directional migration and elmo1- dependent macrophage engulfment.

    Science.gov (United States)

    van Ham, Tjakko J; Kokel, David; Peterson, Randall T

    2012-05-01

    Apoptotic cell death is essential for development and tissue homeostasis. Failure to clear apoptotic cells can ultimately cause inflammation and autoimmunity. Apoptosis has primarily been studied by staining of fixed tissue sections, and a clear understanding of the behavior of apoptotic cells in living tissue has been elusive. Here, we use a newly developed technique to track apoptotic cells in real time as they emerge and are cleared from the zebrafish brain. We find that apoptotic cells are remarkably motile, frequently migrating several cell diameters to the periphery of living tissues. F-actin remodeling occurs in surrounding cells, but also within the apoptotic cells themselves, suggesting a cell-autonomous component of motility. During the first 2 days of development, engulfment is rare, and most apoptotic cells lyse at the brain periphery. By 3 days postfertilization, most cell corpses are rapidly engulfed by macrophages. This engulfment requires the guanine nucleotide exchange factor elmo1. In elmo1-deficient macrophages, engulfment is rare and may occur through macropinocytosis rather than directed engulfment. These findings suggest that clearance of apoptotic cells in living vertebrates is accomplished by the combined actions of apoptotic cell migration and elmo1-dependent macrophage engulfment. PMID:22503503

  5. Systemic Therapy for Metastatic Non-Clear Cell Renal Cell Carcinoma: Recent Progress and Future Directions

    OpenAIRE

    Chowdhury, Simon; Matrana, Marc; Tsang, Christopher; Atkinson, Bradley; Choueiri, Toni K.; Tannir, Nizar M.

    2011-01-01

    Renal cell carcinoma (RCC) encompasses a heterogeneous group of histological subtypes of which clear-cell RCC (CCRCC) is the most common comprising more than 70–80% of all cases. Papillary renal cell carcinoma (PRCC) is the next most common comprising 10–15% of cases. PRCC is refractory to chemotherapy, immunotherapy and hormonal therapy.

  6. The role of bisphosphonates in breast cancer: Direct effects of bisphosphonates on breast cancer cells

    International Nuclear Information System (INIS)

    In addition to inhibiting bone resorption, bisphosphonates have also been shown to exhibit antitumour effects. In vitro, bisphosphonates inhibit proliferation and induce apoptosis in cultured human breast cancer cells. In addition, bisphosphonate treatment interferes with breast cancer cell adhesion to bone matrix, and inhibits cell migration and invasion. The combination of bisphosphonates with other anticancer drugs such as the taxoids markedly enhances these effects. These newly recognized direct actions of bisphosphonates on breast cancer cells indicate that these agents may have a greater role to play in treatment of patients suffering from cancers with a propensity to metastasize to bone

  7. Direct power generation from waste coffee grounds in a biomass fuel cell

    Science.gov (United States)

    Jang, Hansaem; Ocon, Joey D.; Lee, Seunghwa; Lee, Jae Kwang; Lee, Jaeyoung

    2015-11-01

    We demonstrate the possibility of direct power generation from waste coffee grounds (WCG) via high-temperature carbon fuel cell technology. At 900 °C, the WCG-powered fuel cell exhibits a maximum power density that is twice than carbon black. Our results suggest that the heteroatoms and hydrogen contained in WCG are crucial in providing good cell performance due to its in-situ gasification, without any need for pre-reforming. As a first report on the use of coffee as a carbon-neutral fuel, this study shows the potential of waste biomass (e.g. WCG) in sustainable electricity generation in fuel cells.

  8. Comparison between direct and reverse electroporation of cells in situ: a simulation study.

    Science.gov (United States)

    Towhidi, Leila; Khodadadi, Delaram; Maimari, Nataly; Pedrigi, Ryan M; Ip, Henry; Kis, Zoltan; Kwak, Brenda R; Petrova, Tatiana W; Delorenzi, Mauro; Krams, Rob

    2016-03-01

    The discovery of the human genome has unveiled new fields of genomics, transcriptomics, and proteomics, which has produced paradigm shifts on how to study disease mechanisms, wherein a current central focus is the understanding of how gene signatures and gene networks interact within cells. These gene function studies require manipulating genes either through activation or inhibition, which can be achieved by temporarily permeabilizing the cell membrane through transfection to delivercDNAorRNAi. An efficient transfection technique is electroporation, which applies an optimized electric pulse to permeabilize the cells of interest. When the molecules are applied on top of seeded cells, it is called "direct" transfection and when the nucleic acids are printed on the substrate and the cells are seeded on top of them, it is termed "reverse" transfection. Direct transfection has been successfully applied in previous studies, whereas reverse transfection has recently gained more attention in the context of high-throughput experiments. Despite the emerging importance, studies comparing the efficiency of the two methods are lacking. In this study, a model for electroporation of cells in situ is developed to address this deficiency. The results indicate that reverse transfection is less efficient than direct transfection. However, the model also predicts that by increasing the concentration of deliverable molecules by a factor of 2 or increasing the applied voltage by 20%, reverse transfection can be approximately as efficient as direct transfection. PMID:27009275

  9. The Role of Direct Current Electric Field-Guided Stem Cell Migration in Neural Regeneration.

    Science.gov (United States)

    Yao, Li; Li, Yongchao

    2016-06-01

    Effective directional axonal growth and neural cell migration are crucial in the neural regeneration of the central nervous system (CNS). Endogenous currents have been detected in many developing nervous systems. Experiments have demonstrated that applied direct current (DC) electric fields (EFs) can guide axonal growth in vitro, and attempts have been made to enhance the regrowth of damaged spinal cord axons using DC EFs in in vivo experiments. Recent work has revealed that the migration of stem cells and stem cell-derived neural cells can be guided by DC EFs. These studies have raised the possibility that endogenous and applied DC EFs can be used to direct neural tissue regeneration. Although the mechanism of EF-directed axonal growth and cell migration has not been fully understood, studies have shown that the polarization of cell membrane proteins and the activation of intracellular signaling molecules are involved in the process. The application of EFs is a promising biotechnology for regeneration of the CNS. PMID:27108005

  10. Emerging Evidence for MicroRNAs as Regulators of Cancer Stem Cells

    International Nuclear Information System (INIS)

    Cancer stem cells are defined as a subpopulation of cells within a tumor that are capable of self-renewal and differentiation into the heterogeneous cell lineages that comprise the tumor. Many studies indicate that cancer stem cells may be responsible for treatment failure and relapse in cancer patients. The factors that regulate cancer stem cells are not well defined. MicroRNAs (miRNAs) are small non-coding RNAs that regulate translational repression and transcript degradation. miRNAs play a critical role in embryonic and inducible pluripotent stem cell regulation and emerging evidence supports their role in cancer stem cell evolution. To date, miRNAs have been shown to act either as tumor suppressor genes or oncogenes in driving critical gene expression pathways in cancer stem cells in a wide range of human malignancies, including hematopoietic and epithelial tumors and sarcomas. miRNAs involved in cancer stem cell regulation provide attractive, novel therapeutic targets for cancer treatment. This review attempts to summarize progress to date in defining the role of miRNAs in cancer stem cells

  11. Directed in vitro myogenesis of human embryonic stem cells and their in vivo engraftment.

    Directory of Open Access Journals (Sweden)

    Yongsung Hwang

    Full Text Available Development of human embryonic stem cell (hESC-based therapy requires derivation of in vitro expandable cell populations that can readily differentiate to specified cell types and engraft upon transplantation. Here, we report that hESCs can differentiate into skeletal muscle cells without genetic manipulation. This is achieved through the isolation of cells expressing a mesodermal marker, platelet-derived growth factor receptor-α (PDGFRA, following embryoid body (EB formation. The ESC-derived cells differentiated into myoblasts in vitro as evident by upregulation of various myogenic genes, irrespective of the presence of serum in the medium. This result is further corroborated by the presence of sarcomeric myosin and desmin, markers for terminally differentiated cells. When transplanted in vivo, these pre-myogenically committed cells were viable in tibialis anterior muscles 14 days post-implantation. These hESC-derived cells, which readily undergo myogenic differentiation in culture medium containing serum, could be a viable cell source for skeletal muscle repair and tissue engineering to ameliorate various muscle wasting diseases.

  12. MIF Maintains the Tumorigenic Capacity of Brain Tumor-Initiating Cells by Directly Inhibiting p53.

    Science.gov (United States)

    Fukaya, Raita; Ohta, Shigeki; Yaguchi, Tomonori; Matsuzaki, Yumi; Sugihara, Eiji; Okano, Hideyuki; Saya, Hideyuki; Kawakami, Yutaka; Kawase, Takeshi; Yoshida, Kazunari; Toda, Masahiro

    2016-05-01

    Tumor-initiating cells thought to drive brain cancer are embedded in a complex heterogeneous histology. In this study, we isolated primary cells from 21 human brain tumor specimens to establish cell lines with high tumorigenic potential and to identify the molecules enabling this capability. The morphology, sphere-forming ability upon expansion, and differentiation potential of all cell lines were indistinguishable in vitro However, testing for tumorigenicity revealed two distinct cell types, brain tumor-initiating cells (BTIC) and non-BTIC. We found that macrophage migration inhibitory factor (MIF) was highly expressed in BTIC compared with non-BTIC. MIF bound directly to both wild-type and mutant p53 but regulated p53-dependent cell growth by different mechanisms, depending on glioma cell line and p53 status. MIF physically interacted with wild-type p53 in the nucleus and inhibited its transcription-dependent functions. In contrast, MIF bound to mutant p53 in the cytoplasm and abrogated transcription-independent induction of apoptosis. Furthermore, MIF knockdown inhibited BTIC-induced tumor formation in a mouse xenograft model, leading to increased overall survival. Collectively, our findings suggest that MIF regulates BTIC function through direct, intracellular inhibition of p53, shedding light on the molecular mechanisms underlying the tumorigenicity of certain malignant brain cells. Cancer Res; 76(9); 2813-23. ©2016 AACR. PMID:26980763

  13. Investigations on fabrication and lifetime performance of self - air breathing direct hydrogen micro fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Giddey, S.; Badwal, S.P.S.; Ciacchi, F.T.; Fini, D. [CSIRO Energy Technology, Private Bag 33, Clayton South, Victoria 3169 (Australia); Sexton, B.A.; Glenn, F.; Leech, P.W. [CSIRO Materials Science and Engineering, Private Bag 33, Clayton South, Victoria 3169 (Australia)

    2010-03-15

    There is an ever - increasing demand for more powerful, compact and longer - life power modules for portable electronic devices for leisure, communication and computing. Micro fuel cells have the potential to replace battery packs for portable electronic appliances because of their high power density, longer operating and standby times, and substantially shorter recharging times. However, fuel cells have stringent operating requirements, including no fuel leakage, water formed in the electrochemical reactions, heat dissipation, robustness, easy and safe use, and reliability. Due to the large market potential, several companies are currently involved in the development of micro fuel cells. For application of fuel cells as a battery charger or in a battery replacement market, the cells require simplification in terms of their construction and operation and must have volumetric power densities equivalent to or better than those of existing battery power packs. This paper discusses results of investigation on methods and materials for direct hydrogen micro fuel cells as well as the lifetime performance of single cells and 2 W{sub e} arrays. The paper also reviews the global technology development status for the direct hydrogen micro fuel cell and compares its salient features with other types of micro fuel cells. (author)

  14. A combination of small molecules directly reprograms mouse fibroblasts into neural stem cells.

    Science.gov (United States)

    Zheng, Jie; Choi, Kyung-Ah; Kang, Phil Jun; Hyeon, Solji; Kwon, Suhyun; Moon, Jai-Hee; Hwang, Insik; Kim, Yang In; Kim, Yoon Sik; Yoon, Byung Sun; Park, Gyuman; Lee, JangBo; Hong, SungHoi; You, Seungkwon

    2016-07-15

    The generation of induced neural stem cells (iNSCs) from somatic cells using defined factors provides new avenues for basic research and cell therapies for various neurological diseases, such as Parkinson's disease, Huntington's disease, and spinal cord injuries. However, the transcription factors used for direct reprogramming have the potential to cause unexpected genetic modifications, which limits their potential application in cell therapies. Here, we show that a combination of four chemical compounds resulted in cells directly acquiring a NSC identity; we termed these cells chemically-induced NSCs (ciNSCs). ciNSCs expressed NSC markers (Pax6, PLZF, Nestin, Sox2, and Sox1) and resembled NSCs in terms of their morphology, self-renewal, gene expression profile, and electrophysiological function when differentiated into the neuronal lineage. Moreover, ciNSCs could differentiate into several types of mature neurons (dopaminergic, GABAergic, and cholinergic) as well as astrocytes and oligodendrocytes in vitro. Taken together, our results suggest that stably expandable and functional ciNSCs can be directly reprogrammed from mouse fibroblasts using a combination of small molecules without any genetic manipulation, and will provide a new source of cells for cellular replacement therapy of neurodegenerative diseases. PMID:27207831

  15. Performance evaluation of a tubular direct carbon fuel cell operating in a packed bed of carbon

    International Nuclear Information System (INIS)

    The DCFC (direct carbon fuel cell) technology, based on the direct electrochemical oxidation of carbon, has the potential to double the electric efficiency and half the CO2 emissions compared to conventional coal fired power plants. In order to assess the scalability of the technology in terms of fabrication and fuel feed system, and to elucidate the possible causes of the cell degradation, a tubular DCFC has been fabricated and operated in a pulverised carbon packed bed at around 800 °C. The cell was operated for a total period of 11 days with many thermal cycles. The electrochemical impedance spectroscopy was used to elucidate the possible causes of the cell degradation. Post-mortem analysis of the cell with SEM (scanning electron microscopy) and XRD (X-ray diffraction) confirmed structural stability of both air and fuel electrodes. A peak power density of 30 mW cm−2 was obtained by direct contact of carbon to the fuel electrode with high purity He as the purge gas. The cell, at the end of operation was still found to produce 60% of the power relative to the power at the beginning of operation, and this study demonstrates the feasibility of continuous operation of the tubular fuel cell in a packed bed of carbon. - Highlights: • A direct carbon fuel cell was operated for 11 days in a packed carbon bed. • Scalability and continuous operation of fuel cell on solid carbon demonstrated. • MIEC (Mixed ion electronic conducting) anode (LSCF) showed reasonable stability. • Major degradation source is lack of carbon contact with anode as it is consumed

  16. A comparison of policy and direct practice stakeholder perceptions of factors affecting evidence-based practice implementation using concept mapping

    Directory of Open Access Journals (Sweden)

    Green Amy E

    2011-09-01

    Full Text Available Abstract Background The goal of this study was to assess potential differences between administrators/policymakers and those involved in direct practice regarding factors believed to be barriers or facilitating factors to evidence-based practice (EBP implementation in a large public mental health service system in the United States. Methods Participants included mental health system county officials, agency directors, program managers, clinical staff, administrative staff, and consumers. As part of concept mapping procedures, brainstorming groups were conducted with each target group to identify specific factors believed to be barriers or facilitating factors to EBP implementation in a large public mental health system. Statements were sorted by similarity and rated by each participant in regard to their perceived importance and changeability. Multidimensional scaling, cluster analysis, descriptive statistics and t-tests were used to analyze the data. Results A total of 105 statements were distilled into 14 clusters using concept-mapping procedures. Perceptions of importance of factors affecting EBP implementation varied between the two groups, with those involved in direct practice assigning significantly higher ratings to the importance of Clinical Perceptions and the impact of EBP implementation on clinical practice. Consistent with previous studies, financial concerns (costs, funding were rated among the most important and least likely to change by both groups. Conclusions EBP implementation is a complex process, and different stakeholders may hold different opinions regarding the relative importance of the impact of EBP implementation. Implementation efforts must include input from stakeholders at multiple levels to bring divergent and convergent perspectives to light.

  17. Direct evidence of stationary zonal flows and critical gradient behavior for Er during formation of the edge pedestal in JET

    Science.gov (United States)

    Hillesheim, Jon

    2015-11-01

    High spatial resolution measurements with Doppler backscattering in JET have provided new insights into the development of the edge radial electric field during pedestal formation. The characteristics of Er have been studied as a function of density at 2.5 MA plasma current and 3 T toroidal magnetic field. We observe fine-scale spatial structure in the edge Er well prior to the LH transition, consistent with stationary zonal flows. Zonal flows are a fundamental mechanism for the saturation of turbulence and this is the first direct evidence of stationary zonal flows in a tokamak. The radial wavelength of the zonal flows systematically decreases with density. The zonal flows are clearest in Ohmic conditions, weaker in L-mode, and absent in H-mode. Measurements also show that after neutral beam heating is applied, the edge Er builds up at a constant gradient into the core during L-mode, at radii where Er is mainly due to toroidal velocity. The local stability of velocity shear driven turbulence, such as the parallel velocity gradient mode, will be assessed with gyrokinetic simulations. This critical Er shear persists across the LH transition into H-mode. Surprisingly, a reduction in the apparent magnitude of the Er well depth is observed directly following the LH transition at high densities. Establishing the physics basis for the LH transition is important for projecting scalings to ITER and these observations challenge existing models based on increased Er shear or strong zonal flows as the trigger for the transition. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission.

  18. Interleukin 4 (B cell stimulatory factor 1) can mediate the induction of lymphokine-activated killer cell activity directed against fresh tumor cells

    OpenAIRE

    1987-01-01

    Interleukin 4 (IL-4) expresses multiple biologic activities, including B cell, mast cell, and T cell stimulation. We showed that the incubation of resting splenocytes from C57BL/6 mice solely in purified native or recombinant mouse IL-4 results in the generation of lymphokine-activated killer (LAK) activity directed against fresh, syngeneic sarcoma cells. The precursor activated by IL-4 expresses surface asialo-GM1. In addition, IL-4 is capable of amplifying the splenic LAK activity induced b...

  19. Direct inhibition of T-cell responses by the Cryptococcus capsular polysaccharide glucuronoxylomannan.

    Directory of Open Access Journals (Sweden)

    Lauren E Yauch

    2006-11-01

    Full Text Available The major virulence factor of the pathogenic fungi Cryptococcus neoformans and C. gattii is the capsule. Glucuronoxylomannan (GXM, the major component of the capsule, is a high-molecular-weight polysaccharide that is shed during cryptococcosis and can persist in patients after successful antifungal therapy. Due to the importance of T cells in the anticryptococcal response, we studied the effect of GXM on the ability of dendritic cells (DCs to initiate a T-cell response. GXM inhibited the activation of cryptococcal mannoprotein-specific hybridoma T cells and the proliferation of OVA-specific OT-II T cells when murine bone marrow-derived DCs were used as antigen-presenting cells. Inhibition of OT-II T-cell proliferation was observed when either OVA protein or OVA323-339 peptide was used as antigen, indicating GXM did not merely prevent antigen uptake or processing. We found that DCs internalize GXM progressively over time; however, the suppressive effect did not require DCs, as GXM directly inhibited T-cell proliferation induced by anti-CD3 antibody, concanavalin A, or phorbol-12-myristate-13-acetate/ionomycin. Analysis of T-cell viability revealed that the reduced proliferation in the presence of GXM was not the result of increased cell death. GXM isolated from each of the four major cryptococcal serotypes inhibited the proliferation of human peripheral blood mononuclear cells stimulated with tetanus toxoid. Thus, we have defined a new mechanism by which GXM can impart virulence: direct inhibition of T-cell proliferation. In patients with cryptococcosis, this could impair optimal cell-mediated immune responses, thereby contributing to the persistence of cryptococcal infections.

  20. TSCOT+ thymic epithelial cell-mediated sensitive CD4 tolerance by direct presentation.

    Directory of Open Access Journals (Sweden)

    Sejin Ahn

    2008-08-01

    Full Text Available Although much effort has been directed at dissecting the mechanisms of central tolerance, the role of thymic stromal cells remains elusive. In order to further characterize this event, we developed a mouse model restricting LacZ to thymic stromal cotransporter (TSCOT-expressing thymic stromal cells (TDLacZ. The thymus of this mouse contains approximately 4,300 TSCOT+ cells, each expressing several thousand molecules of the LacZ antigen. TSCOT+ cells express the cortical marker CDR1, CD40, CD80, CD54, and major histocompatibility complex class II (MHCII. When examining endogenous responses directed against LacZ, we observed significant tolerance. This was evidenced in a diverse T cell repertoire as measured by both a CD4 T cell proliferation assay and an antigen-specific antibody isotype analysis. This tolerance process was at least partially independent of Autoimmune Regulatory Element gene expression. When TDLacZ mice were crossed to a novel CD4 T cell receptor (TCR transgenic reactive against LacZ (BgII, there was a complete deletion of double-positive thymocytes. Fetal thymic reaggregate culture of CD45- and UEA-depleted thymic stromal cells from TDLacZ and sorted TCR-bearing thymocytes excluded the possibility of cross presentation by thymic dendritic cells and medullary epithelial cells for the deletion. Overall, these results demonstrate that the introduction of a neoantigen into TSCOT-expressing cells can efficiently establish complete tolerance and suggest a possible application for the deletion of antigen-specific T cells by antigen introduction into TSCOT+ cells.

  1. Photobiomodulation Mitigates Diabetes-Induced Retinopathy by Direct and Indirect Mechanisms: Evidence from Intervention Studies in Pigmented Mice.

    Directory of Open Access Journals (Sweden)

    Alexandra Saliba

    Full Text Available Daily application of far-red light from the onset of diabetes mitigated diabetes-induced abnormalities in retinas of albino rats. Here, we test the hypothesis that photobiomodulation (PBM is effective in diabetic, pigmented mice, even when delayed until weeks after onset of diabetes. Direct and indirect effects of PBM on the retina also were studied.Diabetes was induced in C57Bl/6J mice using streptozotocin. Some diabetics were exposed to PBM therapy (4 min/day; 670 nm daily. In one study, mice were diabetic for 4 weeks before initiation of PBM for an additional 10 weeks. Retinal oxidative stress, inflammation, and retinal function were measured. In some mice, heads were covered with a lead shield during PBM to prevent direct illumination of the eye, or animals were treated with an inhibitor of heme oxygenase-1. In a second study, PBM was initiated immediately after onset of diabetes, and administered daily for 2 months. These mice were examined using manganese-enhanced MRI to assess effects of PBM on transretinal calcium channel function in vivo.PBM intervention improved diabetes-induced changes in superoxide generation, leukostasis, expression of ICAM-1, and visual performance. PBM acted in part remotely from the retina because the beneficial effects were achieved even with the head shielded from the light therapy, and because leukocyte-mediated cytotoxicity of retinal endothelial cells was less in diabetics treated with PBM. SnPP+PBM significantly reduced iNOS expression compared to PBM alone, but significantly exacerbated leukostasis. In study 2, PBM largely mitigated diabetes-induced retinal calcium channel dysfunction in all retinal layers.PBM induces retinal protection against abnormalities induced by diabetes in pigmented animals, and even as an intervention. Beneficial effects on the retina likely are mediated by both direct and indirect mechanisms. PBM is a novel non-pharmacologic treatment strategy to inhibit early changes of diabetic

  2. Uterine epithelial cell proliferation and endometrial hyperplasia: evidence from a mouse model.

    Science.gov (United States)

    Gao, Yang; Li, Shu; Li, Qinglei

    2014-08-01

    In the uterus, epithelial cell proliferation changes during the estrous cycle and pregnancy. Uncontrolled epithelial cell proliferation results in implantation failure and/or cancer development. Transforming growth factor-β (TGF-β) signaling is a fundamental regulator of diverse biological processes and is indispensable for multiple reproductive functions. However, the in vivo role of TGF-β signaling in uterine epithelial cells remains poorly defined. We have shown that in the uterus, conditional deletion of the Type 1 receptor for TGF-β (Tgfbr1) using anti-Müllerian hormone receptor type 2 (Amhr2) Cre leads to myometrial defects. Here, we describe enhanced epithelial cell proliferation by immunostaining of Ki67 in the uteri of these mice. The aberration culminated in endometrial hyperplasia in aged females. To exclude the potential influence of ovarian steroid hormones, the proliferative status of uterine epithelial cells was assessed following ovariectomy. Increased uterine epithelial cell proliferation was also revealed in ovariectomized Tgfbr1 Amhr2-Cre conditional knockout mice. We further demonstrated that transcript levels for fibroblast growth factor 10 (Fgf10) were markedly up-regulated in Tgfbr1 Amhr2-Cre conditional knockout uteri. Consistently, treatment of primary uterine stromal cells with TGF-β1 significantly reduced Fgf10 mRNA expression. Thus, our findings suggest a potential involvement of TGFBR1-mediated signaling in the regulation of uterine epithelial cell proliferation, and provide genetic evidence supporting the role of uterine epithelial cell proliferation in the pathogenesis of endometrial hyperplasia. PMID:24770950

  3. Direct effect of ownership and technology import: Firm level evidence from large and medium-enterprises in Shanghai

    Institute of Scientific and Technical Information of China (English)

    ZHU Pingfang; LI Lei

    2007-01-01

    This paper explores the direct effect of ownership and technology imports under the fiamework of neoclassical economic theory.The econometric analysis is based on panel data from a random sample of large and mediumenterprises in Shanghai,during the period of 1998 to 2003.The results show that Sino-foreign joint ventures,Sino-foralgn cooperative enterprises and foreignfunded enterprises (SANZI) enjoy higher labor productivity and total factor productlvity (TFP) than domestic enterprises.Intra-firm diffusion of non-codified technology,proxied by ovwnership,is the main source of their better performance,whereas internally transferred codified technology makes little contribution to TFP.For state-owned enterprises,codified technology imports have significantly raised both labor productivity and TFP,but such positive effect is significantly dependent on the S&T human resource.In contrast,no evidence supports that introduction of foreign technology has enhanced the productivity in domestic nonstate-owned enterprises.The empirical results indicate that SANZI do not have a distinct advantage in their codified technology.In addition,inadequate investment in assimilation process and research and development together with inefficient management of science and technology activities,may impede the use of imported technology.

  4. Crystallographic Evidence for Direct Metal-Metal Bonding in a Stable Open-Shell La2 @Ih -C80 Derivative.

    Science.gov (United States)

    Bao, Lipiao; Chen, Muqing; Pan, Changwang; Yamaguchi, Takahisa; Kato, Tatsuhisa; Olmstead, Marilyn M; Balch, Alan L; Akasaka, Takeshi; Lu, Xing

    2016-03-18

    Endohedral metallofullerenes (EMFs) have novel structures and properties that are closely associated with the internal metallic species. Benzyl radical additions have been previously shown to form closed-shell adducts by attaching an odd number of addends to open-shell EMFs (such as Sc3 C2 @Ih -C80 ) whereas an even number of groups are added to closed-shell EMFs (for example Sc3 N@Ih -C80 ). Herein we report that benzyl radical addition to the closed-shell La2 @Ih -C80 forms a stable, open-shell monoadduct instead of the anticipated closed-shell bisadduct. Single-crystal X-ray diffraction results show the formation of a stable radical species. In this species, the La-La distance is comparable to the theoretical value of a La-La covalent bond and is shorter than reported values for other La2 @Ih -C80 derivatives, providing unambiguous evidence for the formation of direct La-La bond. PMID:26918907

  5. Direct Experimental Evidence for Differing Reactivity Alterations of Minerals following Irradiation: The Case of Calcite and Quartz

    Science.gov (United States)

    Pignatelli, Isabella; Kumar, Aditya; Field, Kevin G.; Wang, Bu; Yu, Yingtian; Le Pape, Yann; Bauchy, Mathieu; Sant, Gaurav

    2016-01-01

    Concrete, used in the construction of nuclear power plants (NPPs), may be exposed to radiation emanating from the reactor core. Until recently, concrete has been assumed immune to radiation exposure. Direct evidence acquired on Ar+-ion irradiated calcite and quartz indicates, on the contrary, that, such minerals, which constitute aggregates in concrete, may be significantly altered by irradiation. More specifically, while quartz undergoes disordering of its atomic structure resulting in a near complete lack of periodicity, calcite only experiences random rotations, and distortions of its carbonate groups. As a result, irradiated quartz shows a reduction in density of around 15%, and an increase in chemical reactivity, described by its dissolution rate, similar to a glassy silica. Calcite however, shows little change in dissolution rate - although its density noted to reduce by ≈9%. These differences are correlated with the nature of bonds in these minerals, i.e., being dominantly ionic or covalent, and the rigidity of the mineral’s atomic network that is characterized by the number of topological constraints (nc) that are imposed on the atoms in the network. The outcomes have major implications on the durability of concrete structural elements formed with calcite or quartz bearing aggregates in nuclear power plants.

  6. Minimal evidence for a direct involvement of twisted gastrulation homolog 1 (TWSG1) gene in human holoprosencephaly.

    Science.gov (United States)

    Kauvar, Emily F; Hu, Ping; Pineda-Alvarez, Daniel E; Solomon, Benjamin D; Dutra, Amalia; Pak, Evgenia; Blessing, Brooke; Proud, Virginia; Shanske, Alan L; Stevens, Cathy A; Rosenfeld, Jill A; Shaffer, Lisa G; Roessler, Erich; Muenke, Maximilian

    2011-04-01

    Holoprosencephaly (HPE) is the most common disorder of human forebrain and facial development. Presently understood etiologies include both genetic and environmental factors, acting either alone, or more likely, in combination. The majority of patients without overt chromosomal abnormalities or recognizable associated syndromes have unidentified etiologies. A potential candidate gene, Twisted Gastrulation Homolog 1 (TWSG1), was previously suggested as a contributor to the complex genetics of human HPE based on (1) cytogenetic studies of patients with 18p deletions, (2) animal studies of TWSG1 deficient mice, and (3) the relationship of TWSG1 to bone morphogenetic protein (BMP) signaling, which modulates the primary pathway implicated in HPE, Sonic Hedgehog (SHH) signaling. Here we present the first analysis of a large cohort of patients with HPE for coding sequence variations in TWSG1. We also performed fine mapping of 18p for a subset of patients with partial 18p deletions. Surprisingly, minimal evidence for alterations of TWSG1 was found, suggesting that sequence alterations of TWSG1 are neither a common direct cause nor a frequent modifying factor for human HPE pathologies. PMID:21227728

  7. The Degradation Interface of Magnesium Based Alloys in Direct Contact with Human Primary Osteoblast Cells

    OpenAIRE

    Ahmad Agha, Nezha; Willumeit-Römer, Regine; Laipple, Daniel; Luthringer, Bérengère; Feyerabend, Frank

    2016-01-01

    Magnesium alloys have been identified as a new generation material of orthopaedic implants. In vitro setups mimicking physiological conditions are promising for material / degradation analysis prior to in vivo studies however the direct influence of cell on the degradation mechanism has never been investigated. For the first time, the direct, active, influence of human primary osteoblasts on magnesium-based materials (pure magnesium, Mg-2Ag and Mg-10Gd alloys) is studied for up to 14 days. Se...

  8. Mixed phase Pt-Ru catalyst for direct methanol fuel cell anode by flame aerosol synthesis

    DEFF Research Database (Denmark)

    Chakraborty, Debasish; Bischoff, H.; Chorkendorff, Ib;

    2005-01-01

    A spray-flame aerosol catalyzation technique was studied for producing Pt-Ru anode electrodes for the direct methanol fuel cell. Catalysts were produced as aerosol nanoparticles in a spray-flame reactor and deposited directly as a thin layer on the gas diffusion layer. The as-prepared catalyst was......Ru1/Vulcan carbon. The kinetics of methanol oxidation on the mixed phase catalyst was also explored by electrochemical impedance spectroscopy. (c) 2005 The Electrochemical Society....

  9. Head Direction Cell Activity Is Absent in Mice without the Horizontal Semicircular Canals.

    Science.gov (United States)

    Valerio, Stephane; Taube, Jeffrey S

    2016-01-20

    Head direction (HD) cells fire when an animal faces a particular direction in its environment, and they are thought to represent the neural correlate of the animal's perceived spatial orientation. Previous studies have shown that vestibular information is critical for generating the HD signal but have not delineated whether information from all three semicircular canals or just the horizontal canals, which are primarily sensitive to angular head rotation in the horizontal (yaw) plane, are critical for the signal. Here, we monitored cell activity in the anterodorsal thalamus (ADN), an area known to contain HD cells, in epstatic circler (Ecl) mice, which have a bilateral malformation of the horizontal (lateral) semicircular canals. Ecl mice and their littermates that did not express the mutation (controls) were implanted with recording electrodes in the ADN. Results confirm the important role the horizontal canals play in forming the HD signal. Although normal HD cell activity (Raleigh's r > 0.4) was recorded in control mice, no such activity was found in Ecl mice, although some cells had activity that was mildly modulated by HD (0.4 > r > 0.2). Importantly, we also observed activity in Ecl mice that was best characterized as bursty--a pattern of activity similar to an HD signal but without any preferred firing direction. These results suggest that the neural structure for the HD network remains intact in Ecl mice, but the absence of normal horizontal canals results in an inability to control the network properly and brings about an unstable HD signal. Significance statement: Cells in the anterior dorsal thalamic nucleus normally fire in relation to the animal's directional heading with respect to the environment--so-called head direction cells. To understand how these head direction cells generate their activity, we recorded single-unit activity from the anterior dorsal thalamus in transgenic mice that lack functional horizontal semicircular canals. We show that the

  10. Direct growth of graphene nanowalls on the crystalline silicon for solar cells

    Science.gov (United States)

    Liu, Jian; Sun, Wentao; Wei, Dapeng; Song, Xuefen; Jiao, Tianpeng; He, Shixuan; Zhang, Wei; Du, Chunlei

    2015-01-01

    We developed a simple approach to fabricate graphene/Si heterojunction solar cells via direct growth of graphene nanowalls on Si substrate. This 3D graphene structure was outstanding electrode network and could form fine interface with Si substrate. Moreover, direct growth method not only simplified manufacturing process, but also avoided damages and contaminants from graphene transfer process. The short-circuit current (Jsc) increased greatly and could reach 31 mA/cm2. After HNO3 doping, the energy conversion efficiency was increased up to 5.1%. Furthermore, we investigated the influence of growth time on the cell performance.

  11. A direct and at nanometer scale study of electrical charge distribution on membranes of alive cells

    Directory of Open Access Journals (Sweden)

    Marlière Christian

    2016-01-01

    Full Text Available In this paper is presented an innovative method to map in-vivo and at nanometer scale the electrical charge distribution on membranes of alive cells. It relies on a new atomic force microscopy (AFM mode based on an electro-mechanical coupling effect. Furthermore, an additional electrical signal detected by both the deflection of the AFM cantilever and simultaneous direct current measurements was detected at low scanning rates. It was attributed to the detection of the current stemming from ionic channels. It opens a new way to directly investigate in situ biological electrical surface processes involved in bacterial adhesion, biofilm formation, microbial fuel cells, etc.

  12. Laser Direct-Write Onto Live Tissues: A Novel Model for Studying Cancer Cell Migration.

    Science.gov (United States)

    Burks, Hope E; Phamduy, Theresa B; Azimi, Mohammad S; Saksena, Jayant; Burow, Matthew E; Collins-Burow, Bridgette M; Chrisey, Douglas B; Murfee, Walter L

    2016-11-01

    Investigation into the mechanisms driving cancer cell behavior and the subsequent development of novel targeted therapeutics requires comprehensive experimental models that mimic the complexity of the tumor microenvironment. Recently, our laboratories have combined a novel tissue culture model and laser direct-write, a form of bioprinting, to spatially position single or clustered cancer cells onto ex vivo microvascular networks containing blood vessels, lymphatic vessels, and interstitial cell populations. Herein, we highlight this new model as a tool for quantifying cancer cell motility and effects on angiogenesis and lymphangiogenesis in an intact network that matches the complexity of a real tissue. Application of our proposed methodology offers an innovative ex vivo tissue perspective for evaluating the effects of gene expression and targeted molecular therapies on cancer cell migration and invasion. J. Cell. Physiol. 231: 2333-2338, 2016. © 2016 Wiley Periodicals, Inc. PMID:26923437

  13. Thermodynamic analysis of Direct Urea Solid Oxide Fuel Cell in combined heat and power applications

    Science.gov (United States)

    Abraham, F.; Dincer, I.

    2015-12-01

    This paper presents a comprehensive steady state modelling and thermodynamic analysis of Direct Urea Solid Oxide Fuel Cell integrated with Gas Turbine power cycle (DU-SOFC/GT). The use of urea as direct fuel mitigates public health and safety risks associated with the use of hydrogen and ammonia. The integration scheme in this study covers both oxygen ion-conducting solid oxide fuel cells (SOFC-O) and hydrogen proton-conducting solid oxide fuel cells (SOFC-H). Parametric case studies are carried out to investigate the effects of design and operating parameters on the overall performance of the system. The results reveal that the fuel cell exhibited the highest level of exergy destruction among other system components. Furthermore, the SOFC-O based system offers better overall performance than that with the SOFC-H option mainly due to the detrimental reverse water-gas shift reaction at the SOFC anode as well as the unique configuration of the system.

  14. Vestibular and Attractor Network Basis of the Head Direction Cell Signal in Subcortical Circuits

    Directory of Open Access Journals (Sweden)

    Benjamin J Clark

    2012-03-01

    Full Text Available Accurate navigation depends on a network of neural systems that encode the moment-to-moment changes in an animal’s directional orientation and location in space. Within this navigation system are head direction (HD cells, which fire persistently when an animal’s head is pointed in a particular direction (Sharp et al., 2001a; Taube, 2007. HD cells are widely thought to underlie an animal’s sense of spatial orientation, and research over the last 25+ years has revealed that this robust spatial signal is widely distributed across subcortical and cortical limbic areas. Much of this work has been directed at understanding the functional organization of the HD cell circuitry, and precisely how this signal is generated from sensory and motor systems. The purpose of the present review is to summarize some of the recent studies arguing that the HD cell circuit is largely processed in a hierarchical fashion, following a pathway involving the dorsal tegmental nuclei → lateral mammillary nuclei → anterior thalamus → parahippocampal and retrosplenial cortical regions. We also review recent work identifying “bursting” cellular activity in the HD cell circuit after lesions of the vestibular system, and relate these observations to the long held view that attractor network mechanisms underlie HD signal generation. Finally, we summarize the work to date suggesting that this network architecture may reside within the tegmento-mammillary circuit.

  15. Development of a Cell-based Model to Derive Direct Runoff Hydrographs for Ungauged Mountainous Basins

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A model to derive direct runoff hydrograph for an ungauged basin using the physical properties of the basin is presented. The basin is divided into grid cells and canal elements. Overland flow is generated from each grid cell of the basin by application of continuous effective rainfall of 1 mm/hr to the basin. The flow generated is routed through downstream grid cells and the canal elements using the kinematic wave approach. The travel time for direct runoff from each grid cell to the basin outlet is calculated and the S-curve is derived for the basin.The S-curve is used to derive the unit hydrograph of a given duration for the basin. The model, referred as Cell-basin model was applied to the Upper Kotmale Basin in Sri Lanka and the model predictions of direct runoff hydrographs for rainfall events agreed with the observations to a reasonable accuracy. Comparison of the unit hydrographs obtained from the model and from the conventional Snyder's synthetic unit hydrograph using regionalized parameters assuming the basin as an ungauged basin, with the unit hydrograph derived from the observations showed that the model predicted unit hydrograph was more suitable than that obtained by Snyder's method for Sri Lankan up country basins. Thus, the present model is a useful tool to obtain direct runoff hydrograph for ungauged basins.

  16. Tre1, a G protein-coupled receptor, directs transepithelial migration of Drosophila germ cells.

    Directory of Open Access Journals (Sweden)

    Prabhat S Kunwar

    2003-12-01

    Full Text Available In most organisms, germ cells are formed distant from the somatic part of the gonad and thus have to migrate along and through a variety of tissues to reach the gonad. Transepithelial migration through the posterior midgut (PMG is the first active step during Drosophila germ cell migration. Here we report the identification of a novel G protein-coupled receptor (GPCR, Tre1, that is essential for this migration step. Maternal tre1 RNA is localized to germ cells, and tre1 is required cell autonomously in germ cells. In tre1 mutant embryos, most germ cells do not exit the PMG. The few germ cells that do leave the midgut early migrate normally to the gonad, suggesting that this gene is specifically required for transepithelial migration and that mutant germ cells are still able to recognize other guidance cues. Additionally, inhibiting small Rho GTPases in germ cells affects transepithelial migration, suggesting that Tre1 signals through Rho1. We propose that Tre1 acts in a manner similar to chemokine receptors required during transepithelial migration of leukocytes, implying an evolutionarily conserved mechanism of transepithelial migration. Recently, the chemokine receptor CXCR4 was shown to direct migration in vertebrate germ cells. Thus, germ cells may more generally use GPCR signaling to navigate the embryo toward their target.

  17. Tre1, a G Protein-Coupled Receptor, Directs Transepithelial Migration of Drosophila Germ Cells

    Directory of Open Access Journals (Sweden)

    Kunwar Prabhat S

    2003-01-01

    Full Text Available In most organisms, germ cells are formed distant from the somatic part of the gonad and thus have to migrate along and through a variety of tissues to reach the gonad. Transepithelial migration through the posterior midgut (PMG is the first active step during Drosophila germ cell migration. Here we report the identification of a novel G protein-coupled receptor (GPCR, Tre1, that is essential for this migration step. Maternal tre1 RNA is localized to germ cells, and tre1 is required cell autonomously in germ cells. In tre1 mutant embryos, most germ cells do not exit the PMG. The few germ cells that do leave the midgut early migrate normally to the gonad, suggesting that this gene is specifically required for transepithelial migration and that mutant germ cells are still able to recognize other guidance cues. Additionally, inhibiting small Rho GTPases in germ cells affects transepithelial migration, suggesting that Tre1 signals through Rho1. We propose that Tre1 acts in a manner similar to chemokine receptors required during transepithelial migration of leukocytes, implying an evolutionarily conserved mechanism of transepithelial migration. Recently, the chemokine receptor CXCR4 was shown to direct migration in vertebrate germ cells. Thus, germ cells may more generally use GPCR signaling to navigate the embryo toward their target.

  18. Single cell migration in oral squamous cell carcinoma - possible evidence of epithelial-mesenchymal transition in vivo

    DEFF Research Database (Denmark)

    Jensen, David H; Reibel, Jesper; Mackenzie, Ian C;

    2015-01-01

    carcinomas, their relationship has not been examined in detail. METHODS: Paraffin-embedded tissues from 28 patients with oral squamous cell carcinomas were stained with antibodies to cytokeratin, α-SMA, vimentin, E-cadherin, N-cadherin and Twist and evaluated for their expression in relation to invasive......BACKGROUND: The invasion of cancer cells into the surrounding normal tissue is one of the defining features of cancer. While the phenomena of tumour budding, epithelial-mesenchymal transition and the presence of myofibroblasts have independently been shown to be related to a poor prognosis of oral...... cancer cells and the surrounding tumour stroma. RESULTS AND CONCLUSIONS: A direct, histological relationship between invading, budding tumour cells and myofibroblasts was occasionally seen but was not a general feature. Most of the budding tumour cells at the invasive front had a decreased expression of...

  19. Studies on multiple thyroid cell membrane-directed antibodies in Graves' disease.

    OpenAIRE

    Zakarija, M; Garcia, A.; McKenzie, J. M.

    1985-01-01

    Immunoglobulin G was obtained from the serum of a woman who had given birth to three children with a delayed onset of hyperthyroidism; the clinical events were due to the coexistence of thyroid-stimulating antibody (TSAb) and an inhibitor of TSAb in the maternal serum. The current studies explore the possible existence of additional thyroid membrane-directed antibodies. Human thyroid slices, cells in monolayer culture, and functioning rat thyroid cells (FRTL5), with measurement of cyclic AMP ...

  20. Analyzing the Direct Methanol Fuel Cell technology in portable applications by a historical and bibliometric analysis

    OpenAIRE

    Suominen, A.; Tuominen, A. (Aulis)

    2010-01-01

    The development of direct methanol fuel cell (DMFC) technology through an analysis of research, patenting and commercial adoption is studied in this paper. The analysis uses a dataset gathered from both publication and patent databases. This data is complemented with a review on commercial efforts on portable fuel cells. Bibliometric methods are used to identify research networks and research trends. The Fisher-Pry growth model is used to estimate future research activity. The patent landscap...

  1. Direct and indirect measurement of somatic cell count as indicator of intramammary infection in dairy goats

    OpenAIRE

    Olofsson Ida; Persson Ylva

    2011-01-01

    Abstract Background Mastitis is the most important and costly disease in dairy goat production. Subclinical mastitis is common in goats and is mainly caused by contagious bacteria. Several methods to diagnose subclinical mastitis are available. In this study indirect measurement of somatic cell count (SCC) by California Mastitis Test (CMT) and direct measurement of SCC using a portable deLaval cell counter (DCC) are evaluated. Swedish goat farmers would primarily benefit from diagnostic metho...

  2. Tie-1-directed expression of Cre recombinase in endothelial cells of embryoid bodies and transgenic mice

    DEFF Research Database (Denmark)

    Gustafsson, E; Brakebusch, C; Hietanen, K;

    2001-01-01

    germline chimeras. The in vivo efficiency and specificity of the transgenic Cre was analysed by intercrossing the tie-1-Cre line with the ROSA26R reporter mice. At initial stages of vascular formation (E8-9), LacZ staining was detected in almost all cells of the forming vasculature. Between E10 and birth....... These results show that the tie-1-Cre transgenic strain can efficiently direct deletion of floxed genes in endothelial cells in vivo....

  3. Direct-write bioprinting of cell-laden methacrylated gelatin hydrogels

    International Nuclear Information System (INIS)

    Fabrication of three dimensional (3D) organoids with controlled microarchitectures has been shown to enhance tissue functionality. Bioprinting can be used to precisely position cells and cell-laden materials to generate controlled tissue architecture. Therefore, it represents an exciting alternative for organ fabrication. Despite the rapid progress in the field, the development of printing processes that can be used to fabricate macroscale tissue constructs from ECM-derived hydrogels has remained a challenge. Here we report a strategy for bioprinting of photolabile cell-laden methacrylated gelatin (GelMA) hydrogels. We bioprinted cell-laden GelMA at concentrations ranging from 7 to 15% with varying cell densities and found a direct correlation between printability and the hydrogel mechanical properties. Furthermore, encapsulated HepG2 cells preserved cell viability for at least eight days following the bioprinting process. In summary, this work presents a strategy for direct-write bioprinting of a cell-laden photolabile ECM-derived hydrogel, which may find widespread application for tissue engineering, organ printing and the development of 3D drug discovery platforms. (paper)

  4. 4D Tumorigenesis Model for Quantitating Coalescence, Directed Cell Motility and Chemotaxis, Identifying Unique Cell Behaviors, and Testing Anticancer Drugs.

    Science.gov (United States)

    Kuhl, Spencer; Voss, Edward; Scherer, Amanda; Lusche, Daniel F; Wessels, Deborah; Soll, David R

    2016-01-01

    A 4D high-resolution computer-assisted reconstruction and motion analysis system has been developed and applied to the long-term (14-30 days) analysis of cancer cells migrating and aggregating within a 3D matrix. 4D tumorigenesis models more closely approximate the tumor microenvironment than 2D substrates and, therefore, are improved tools for elucidating the interactions within the tumor microenvironment that promote growth and metastasis. The model we describe here can be used to analyze the growth of tumor cells, aggregate coalescence, directed cell motility and chemotaxis, matrix degradation, the effects of anticancer drugs, and the behavior of immune and endothelial cells mixed with cancer cells. The information given in this chapter is also intended to acquaint the reader with computer-assisted methods and algorithms that can be used for high-resolution 3D reconstruction and quantitative motion analysis. PMID:27271907

  5. A novel in vitro flow system for changing flow direction on endothelial cells

    OpenAIRE

    Wang, Chong; LU, Hao; Schwartz, Martin Alexander

    2012-01-01

    Atherosclerotic plaques localize to regions of flow disturbance, i.e. bifurcations, branch points and regions of high curvature. Shear stress in these regions can be multi-directional due to complex flow patterns such as time-varying vortices. However, commonly used in vitro flow models are incapable of changing flow orientation to any direction other than the reverse. We have developed a novel in vitro flow system to enable changes in flow direction to any angle. When cells were pre-aligned ...

  6. Directing energy transport in organic photovoltaic cells using interfacial exciton gates.

    Science.gov (United States)

    Menke, S Matthew; Mullenbach, Tyler K; Holmes, Russell J

    2015-04-28

    Exciton transport in organic semiconductors is a critical, mediating process in many optoelectronic devices. Often, the diffusive and subdiffusive nature of excitons in these systems can limit device performance, motivating the development of strategies to direct exciton transport. In this work, directed exciton transport is achieved with the incorporation of exciton permeable interfaces. These interfaces introduce a symmetry-breaking imbalance in exciton energy transfer, leading to directed motion. Despite their obvious utility for enhanced exciton harvesting in organic photovoltaic cells (OPVs), the emergent properties of these interfaces are as yet uncharacterized. Here, directed exciton transport is conclusively demonstrated in both dilute donor and energy-cascade OPVs where judicious optimization of the interface allows exciton transport to the donor-acceptor heterojunction to occur considerably faster than when relying on simple diffusion. Generalized systems incorporating multiple exciton permeable interfaces are also explored, demonstrating the ability to further harness this phenomenon and expeditiously direct exciton motion, overcoming the diffusive limit. PMID:25798712

  7. Status and future directions of InP solar cell research

    Science.gov (United States)

    Jain, R. K.; Weinberg, I.

    1992-01-01

    An overview of the current status and future directions of InP space solar cell research is provided. The scope of the paper does not allow us to discuss other recent major developments in InP cell modeling, contacts, and characterization, or developments in other solar cell materials. Solar cells made from InP and related materials are not expected to be used in the near future for terrestrial applications, but significant Air-Mass1.5 (AM1.5) cell efficiencies are given for comparison. This paper deals with the developments in single-junction cells, multijunction tandem cells, and space flight testing, including radiation effects. Concentrator InP solar cells are also discussed, since they offer the possibility of simultaneous thermal and current injection annealing. These cells also promise cost effectiveness and the concentrator elements may provide cells with extra protection from space radiation. The concluding section addresses the steps to be taken in the future and provides guidelines for further research and development.

  8. Proton Beam Therapy for Non-Small Cell Lung Cancer: Current Clinical Evidence and Future Directions

    OpenAIRE

    Berman, Abigail T.; Sara St. James; Ramesh Rengan

    2015-01-01

    Lung cancer is the leading cancer cause of death in the United States. Radiotherapy is an essential component of the definitive treatment of early-stage and locally-advanced lung cancer, and the palliative treatment of metastatic lung cancer. Proton beam therapy (PBT), through its characteristic Bragg peak, has the potential to decrease the toxicity of radiotherapy, and, subsequently improve the therapeutic ratio. Herein, we provide a primer on the physics of proton beam therapy for lung canc...

  9. L3MBTL1 Deficiency Directs the Differentiation of Human Embryonic Stem Cells Toward Trophectoderm

    OpenAIRE

    Hoya-Arias, Ruben; Tomishima, Mark; Perna, Fabiana; Voza, Francesca; Nimer, Stephen D.

    2011-01-01

    Human embryonic stem cells (hESCs) can be used to study the early events in human development and, hopefully, to understand how to differentiate human pluripotent cells for clinical use. To define how L3MBTL1, a chromatin-associated polycomb group protein with transcriptional repressive activities, regulates early events in embryonic cell differentiation, we created hESC lines that constitutively express shRNAs directed against L3MBTL1. The L3MBTL1 knockdown (KD) hESCs maintained normal morph...

  10. In-chip fabrication of free-form 3D constructs for directed cell migration analysis

    DEFF Research Database (Denmark)

    Olsen, Mark Holm; Hjortø, Gertrud Malene; Hansen, Morten;

    2013-01-01

    Free-form constructs with three-dimensional (3D) microporosity were fabricated by two-photon polymerization inside the closed microchannel of an injection-molded, commercially available polymer chip for analysis of directed cell migration. Acrylate constructs were produced as woodpile topologies...... with a range of pore sizes from 5 × 5 μm to 15 × 15 μm and prefilled with fibrillar collagen. Dendritic cells seeded into the polymer chip in a concentration gradient of the chemoattractant CCL21 efficiently negotiated the microporous maze structure for pore sizes of 8 × 8 μm or larger. The cells...

  11. Evidence for paracrine/autocrine regulation of GLP-1-producing cells

    DEFF Research Database (Denmark)

    Kappe, Camilla; Zhang, Qimin; Holst, Jens Juul;

    2013-01-01

    Glucagon-like peptide-1 (GLP-1), secreted from gut L cells upon nutrient intake, forms the basis for novel drugs against type 2 diabetes (T2D). Secretion of GLP-1 has been suggested to be impaired in T2D and in conditions associated with hyperlipidemia and insulin resistance. Further, recent...... studies support lipotoxicity of GLP-1-producing cells in vitro. However, little is known about the regulation of L-cell viability/function, the effects of insulin signaling, or the potential effects of stable GLP-1 analogs and dipeptidyl peptidase-4 (DPP-4) inhibitors. We determined effects of insulin as...... well as possible autocrine action of GLP-1 on viability/apoptosis of GLP-1-secreting cells in the presence/absence of palmitate, while also assessing direct effects on function. The studies were performed using the GLP-1-secreting cell line GLUTag, and palmitate was used to simulate hyperlipidemia. Our...

  12. Structural Evidence for Direct Interactions Between the BRCT Domains of Human BRCA1 and a Phospho-Peptide from Human ACC1

    Energy Technology Data Exchange (ETDEWEB)

    Shen,Y.; Tong, L.

    2008-01-01

    The tandem BRCA1 C-terminal (BRCT) domains are phospho-serine/threonine recognition modules essential for the function of BRCA1. Recent studies suggest that acetyl-CoA carboxylase 1 (ACC1), an enzyme with crucial roles in de novo fatty acid biosynthesis and lipogenesis and essential for cancer cell survival, may be a novel binding partner for BRCA1, through interactions with its BRCT domains. We report here the crystal structure at 3.2 Angstroms resolution of human BRCA1 BRCT domains in complex with a phospho-peptide from human ACC1 (p-ACC1 peptide, with the sequence 1258-DSPPQ-pS-PTFPEAGH-1271), which provides molecular evidence for direct interactions between BRCA1 and ACC1. The p-ACC1 peptide is bound in an extended conformation, located in a groove between the tandem BRCT domains. There are recognizable and significant structural differences to the binding modes of two other phospho-peptides to these domains, from BACH1 and CtIP, even though they share a conserved pSer-Pro-(Thr/Val)-Phe motif. Our studies establish a framework for understanding the regulation of lipid biosynthesis by BRCA1 through its inhibition of ACC1 activity, which could be a novel tumor suppressor function of BRCA1.

  13. Is cell viability always directly related to corrosion resistance of stainless steels?

    Science.gov (United States)

    Salahinejad, E; Ghaffari, M; Vashaee, D; Tayebi, L

    2016-05-01

    It has been frequently reported that cell viability on stainless steels is improved by increasing their corrosion resistance. The question that arises is whether human cell viability is always directly related to corrosion resistance in these biostable alloys. In this work, the microstructure and in vitro corrosion behavior of a new class of medical-grade stainless steels were correlated with adult human mesenchymal stem cell viability. The samples were produced by a powder metallurgy route, consisting of mechanical alloying and liquid-phase sintering with a sintering aid of a eutectic Mn-Si alloy at 1050 °C for 30 and 60 min, leading to nanostructures. In accordance with transmission electron microscopic studies, the additive particles for the sintering time of 30 min were not completely melted. Electrochemical impedance spectroscopic experiments suggested the higher corrosion resistance for the sample sintered for 60 min; however, a better cell viability on the surface of the less corrosion-resistant sample was unexpectedly found. This behavior is explained by considering the higher ion release rate of the Mn-Si additive material, as preferred sites to corrosion attack based on scanning electron microscopic observations, which is advantageous to the cells in vitro. In conclusion, cell viability is not always directly related to corrosion resistance in stainless steels. Typically, the introduction of biodegradable and biocompatible phases to biostable alloys, which are conventionally anticipated to be corrosion-resistant, can be advantageous to human cell responses similar to biodegradable metals. PMID:26952444

  14. Micro direct methanol fuel cell with perforated silicon-plate integrated ionomer membrane

    DEFF Research Database (Denmark)

    Larsen, Jackie Vincent; Dalslet, Bjarke Thomas; Johansson, Anne-Charlotte Elisabeth Birgitta;

    2014-01-01

    This article describes the fabrication and characterization of a silicon based micro direct methanol fuel cell using a Nafion ionomer membrane integrated into a perforated silicon plate. The focus of this work is to provide a platform for micro- and nanostructuring of a combined current collector...

  15. Collision Tumor With Renal Cell Carcinoma and Plasmacytoma: Further Evidence of a Renal Cell and Plasma Cell Neoplasm Relationship?

    Science.gov (United States)

    Berquist, Sean W; Hassan, Abd-Elrahman Said; Miakicheva, Olga; Dufour, Catherine; Hamilton, Zachary; Shabaik, Ahmed; Derweesh, Ithaar H

    2016-05-01

    Renal solitary extramedullary plasmacytomas belong to a group of plasma cell neoplasms, which generally have been associated with renal cell carcinoma. We present a case report of a patient with collision tumor histology of extramedullary plasmacytoma and clear cell renal cell carcinoma, the first in the known literature. Standard work-up for a plasma cell neoplasm was conducted and the mass was resected. The patient remains disease-free at 28 months post-surgery. The report calls into question pre-surgical renal mass biopsy protocol and suggests a relationship between renal cell carcinoma and plasma cell neoplasms. PMID:27175345

  16. T Cell-Tumor Interaction Directs the Development of Immunotherapies in Head and Neck Cancer

    Directory of Open Access Journals (Sweden)

    A. E. Albers

    2010-01-01

    Full Text Available The competent immune system controls disease effectively due to induction, function, and regulation of effector lymphocytes. Immunosurveillance is exerted mostly by cytotoxic T-lymphocytes (CTLs while specific immune suppression is associated with tumor malignancy and progression. In squamous cell carcinoma of the head and neck, the presence, activity, but also suppression of tumor-specific CTL have been demonstrated. Functional CTL may exert a selection pressure on the tumor cells that consecutively escape by a combination of molecular and cellular evasion mechanisms. Certain of these mechanisms target antitumor effector cells directly or indirectly by affecting cells that regulate CTL function. This results in the dysfunction or apoptosis of lymphocytes and dysregulated lymphocyte homeostasis. Another important tumor-escape mechanism is to avoid recognition by dysregulation of antigen processing and presentation. Thus, both induction of functional CTL and susceptibility of the tumor and its microenvironment to become T cell targets should be considered in CTL-based immunotherapy.

  17. The impact of mass transport and methanol crossover on the direct methanol fuel cell

    Science.gov (United States)

    Scott, K.; Taama, W. M.; Argyropoulos, P.; Sundmacher, K.

    The performance of a liquid feed direct methanol fuel cell based on a Nafion® solid polymer electrolyte membrane is reported. The cell utilises a porous Pt-Ru-carbon supported catalyst anode. The effect of cell temperature, air cathode pressure, methanol fuel flow rate and methanol concentration on the power performance of a small-scale (9 cm 2 area) cell is described. Data reported is analysed in terms of semi-empirical models for the effect of methanol crossover by diffusion on cathode potential and thus cell voltage. Mass transfer characteristics of the anode reaction are interpreted in terms of the influence of carbon dioxide gas evolution and methanol diffusion in the carbon cloth diffusion layer. Preliminary evaluation of reaction orders and anode polarisation agree with a previous suggested mechanism for methanol oxidation involving a rate limiting step of surface reaction between adsorbed CO and OH species.

  18. Combined local current distribution measurements and high resolution neutron radiography of operating direct methanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, Alexander; Wippermann, Klaus [Forschungszentrum Juelich GmbH (Germany). Inst. of Energy Research, IEF-3: Fuel Cells; Sanders, Tilman [RWTH Aachen (DE). Inst. for Power Electronics and Electrical Drives (ISEA); Arlt, Tobias [Helmholtz Centre Berlin (Germany). Inst. for Applied Materials

    2010-07-01

    Neutron radiography allows the investigation of the local fluid distribution in direct methanol fuel cells (DMFCs) under operating conditions. Spatial resolutions in the order of some tens of micrometers at the full test cell area are achieved. This offers the possibility to study practice-oriented, large stack cells with an active area of several hundred cm{sup 2} as well as specially designed, small test cells with an area of some cm{sup 2}. Combined studies of high resolution neutron radiography and segmented cell measurements are especially valuable, because they enable a correlation of local fluid distribution and local performance [1, 2]. The knowledge of this interdependency is essential to optimise the water management and performance respecting a homogeneous fluid, current and temperature distribution and to achieve high performance and durability of DMFCs. (orig.)

  19. A Src inhibitor regulates the cell cycle of human pluripotent stem cells and improves directed differentiation

    OpenAIRE

    Chetty, Sundari; Engquist, Elise N.; Mehanna, Elie; Lui, Kathy O.; Tsankov, Alexander M.; Douglas A Melton

    2015-01-01

    Driving human pluripotent stem cells (hPSCs) into specific lineages is an inefficient and challenging process. We show that a potent Src inhibitor, PP1, regulates expression of genes involved in the G1 to S phase transition of the cell cycle, activates proteins in the retinoblastoma family, and subsequently increases the differentiation propensities of hPSCs into all three germ layers. We further demonstrate that genetic suppression of Src regulates the activity of the retinoblastoma protein ...

  20. New evidence for the etiology of the so-called radiation caries. Proof for direct radiogenic damage of the dento-enamel junction

    International Nuclear Information System (INIS)

    Methods: A systematic study is presented, comparing teeth with a manifest radiation caries (group 1, about 60 Gy, long interval to the extraction) and clinically caries free teeth (group 2, about 30 Gy, short interval) with tooth specimens after an experimental enoral (in situ) irradiation (60 Gy, group 3) and after in vitro irradiation (500 to 2.500 Gy, group 4). 60Co was the irradiation source. Sound teeth were used as a standard (group 5). For non destructive visualisation of subsurface histotomograms by confocal laser scanning microscopy (CLSM) teeth were either used as fresh sections or as Technovit embedded thin slices (sawing grinding technique). Results: Tooth samples from radiotherapy patients (cancer therapeutic doses, long interval before extraction; group 1) showed three characteristic changes: 1. Rarefication of the branching (ramification) of odontoblast processes near the junction, 2. dentine tubules end infront of the interface to the hard tissue and 3. in dentine the interface is characterised by a zone (about 10 μm wide) of low intensity of the remitted light. Conclusions: The obliteration of the dentine tubules, preceded by a degeneration of the odontoblast processes, is obviously the result of a direct radiogenic cell damage with hampered vascularisation and metabolism particularly in the area of the terminations of the odontoblast processes. The deficit in metabolism combined with a latent damage of the parenchyma (hypo-remitting zone) is evidence for the functional symptoms (subsurface caries). The prerequisite for the micromorphological manifestation of this direct irradiation damage is a vital tooth and in consequence cannot be simulated in situ or in vivo. (orig./MG)