390,708 research outputs found
Representative Bureaucracy and the Willingness to Coproduce: An Experimental Study
No full textRelying on the theory of representative bureaucracy—specifically, the notion of symbolic representation—this article examines whether varying the number of female public officials overseeing a local recycling program influences citizens’ (especially women's) willingness to cooperate with the government by recycling, thus coproducing important policy outcomes. Using a survey experiment in which the first names of public officials are manipulated, the authors find a clear pattern of increasing willingness on the part of women to coproduce when female names are more represented in the agency responsible for recycling, particularly with respect to the more difficult task of composting food waste. Overall, men in the experiment were less willing to coproduce across all measures and less responsive to the gender balance of names. These findings have important implications for the theory of representative bureaucracy and for efforts to promote the coproduction of public services.This is the peer reviewed version of the following article: Riccucci, Norma M., Van Ryzin, Gregg G. & Li, Huafang. (2015). Representative Bureaucracy and the Willingness to Coproduce: An Experimental Study. Public Administration Review, which has been published in final form at http://dx.doi.org/10.1111/puar.12401. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.Peer reviewe
Characterization of an alternatively spliced G(M2) activator protein, G(M2A) protein - An activator protein which stimulates the enzymatic hydrolysis of N-acetylneuraminic acid, but not N-acetylgalactosamine, from G(M2)
No full textG(M2) activator protein is a protein cofactor which stimulates the enzymatic hydrolysis of both GalNAc and NeuAc from G(M2). We have previously isolated two cDNA clones, G(M2) activator cDNA and G(M2A) cDNA, for human G(M2) activator protein (Nagarajan, S., Chen, H.-C., Li, S.-C., Li, Y.-T., and Lockyer, J. M. (1992) Biochem. J. 282, 807-813). G(M2A) mRNA is an RNA alternative splicing product that contains exons 1, 2, 3, and intron 3 of the genomic DNA sequence of G(M2) activator protein (Klima, H., Tanaka, A., Schnabel, D., Nakano, T., Schroder, M., Suzuki, K., and Sandhoff, K. (1991) FEES Left. 289, 260-264). G(M2A) cDNA encodes a protein (G(M2A) protein) containing 1-109 of the 160 amino acids of human G(M2) activator protein, plus a tripeptide (VST) encoded by intron 3 at the COOH terminus. Thus, G(M2A) protein can be regarded as a form (truncated version) of G(M2) activator protein. We have expressed G(M2A) cDNA in Escherichia coli using pT7-7 as the vector. The recombinant G(M2A) protein was purified to an electrophoretically homogeneous form and was found to stimulate the hydrolysis of NeuAc from G(M2) by clostridial sialidase, but not the hydrolysis of GalNAc from G(M2) by beta-hexosaminidase A. Like G(M2) activator protein, G(M2A) protein also specifically recognized the terminal G(M2) epitope in GalNAc-GD1a and stimulated the hydrolysis of only the external NeuAc from this ganglioside by clostridial sialidase. These results enabled us to discern the enzymatic hydrolyses of GalNAc and NeuAc from the G(M2) epitope and established that the NeuAc recognition domain of G(M2) activator protein is located within amino acids 1-109. The presence of G(M2A) mRNA in human tissues and the selective stimulation of NeuAc hydrolysis by G(M2A) protein indicate that this activator protein may be involved in the catabolism of G(M2) through the asialo-G(M2) pathway
SPECIFIC RECOGNITION OF N-ACETYLNEURAMINIC ACID IN THE G(M2) EPITOPE BY HUMAN G(M2) ACTIVATOR PROTEIN
No full textG(M2) Activator is a low molecular weight protein cofactor that stimulates the enzymatic conversion of G(M2) into G(M3) by human beta-hexosaminidase A and also the conversion of G(M2) into G(A2) by clostridial sialidase (Wu, Y.-Y., Lockyer, J. M., Sugiyama, E., Pavlova, N. V., Li, Y.-T., and Li, S.- C. (1994) J. Biol. Chem. 269, 16276-16283). Among the five known activator proteins for the enzymatic hydrolysis of glycosphingolipids, only G(M2) activator is effective in stimulating the hydrolysis of G(M2). However, the mechanism of action of G(M2) activator is still not well understood, Using a unique disialosylganglioside, GalNAc-G(D1a), as the substrate, we were able to show that in the presence of G(M2) activator, GalNAc-G(D1a) was specifically converted into GalNAc-G(M1a) by clostridial sialidase, while in the presence of saposin B, a nonspecific activator protein, GalNAc-G(D1a) was converted into both GalNAc-G(M1a) and GalNAc-G(M1b). individual products generated from GalNAc-G(D1a) by clostridial sialidase were identified by thin layer chromatography, negative secondary ion mass spectrometry, and immunostaining with a monoclonal IgM that recognizes the G(M2) epitope. Our results clearly show that G(M2) activator recognizes the G(M2) epitope in GalNAc-G(D1a). Thus, G(M2) activator may interact with the trisaccharide structure of the G(M2) epitope and render the GalNAc and NeuAc residues accessible to beta-hexosaminidase A and sialidase, respectively
Distribution and morphology of two endemic gomphonemoid species, Gohphonema kaznakowi Mereschkowsky and G-yangtzensis Li nov sp in China
No full textThe morphology of Gomphonema kaznakowi Mereschkowsky was investigated using light microscopy. This species has two morphologically distinct areas near the headpole; an unornamented and an ornamented area. The two areas are distinguished from each other by the combination of size and striae number. A new species, Gomphonema yangtzensis Li nov. sp. is identified based on an ornamented area near the headpole. G. kaznakowi is reported from the upper and middle part of the Yangtze River, and was also found in the upper section of the Yellow River. G. yangtzensis was found in the upper area of the Yellow River and the middle of the Yangtze River. Their limited distribution may be due to certain environmental conditions or a different dispersal rate. Both species are illustrated.The morphology of Gomphonema kaznakowi Mereschkowsky was investigated using light microscopy. This species has two morphologically distinct areas near the headpole; an unornamented and an ornamented area. The two areas are distinguished from each other by the combination of size and striae number. A new species, Gomphonema yangtzensis Li nov. sp. is identified based on an ornamented area near the headpole. G. kaznakowi is reported from the upper and middle part of the Yangtze River, and was also found in the upper section of the Yellow River. G. yangtzensis was found in the upper area of the Yellow River and the middle of the Yangtze River. Their limited distribution may be due to certain environmental conditions or a different dispersal rate. Both species are illustrated
Wang Li (1900-1986)
No full textWang Li (Wang Liaoyi) was one of the three most prominent linguists in China in the 20th century. He was born August 10, 1900, in what is now Bobai County of the Guangxi Zhuang Autonomous Area
Li-rich layered Li1.2Mn0.54Ni0.13Co0.13O2 derived from transition metal carbonate with a micro-nanostructure as a cathode material for high-performance Li-ion batteries
No full text
Compared to commercialized cathode materials, Li-rich layered oxide exhibits a superior mass energy density. However, owing to its low tap/press density, the advantage of its volume energy density is not as obvious as that of its mass energy density, which limits its applications in some volume-constrained fields. It has been shown that the morphology of the precursor is critical to the performances of the final product. Here, solvothermal and co-precipitation methods were adopted to synthesize transition metal carbonate balls with micro-size particles to obtain high-density Li-rich layered oxides. The solvothermal synthesized carbonate showed a micro-nano hierarchical structure composed of nanoplates as subunits, and the co-precipitated synthesized carbonate just presents a micrometer quasi-ball morphology. The Li1.2Mn0.54Ni0.13Co0.13O2 derived from the above solvothermal synthesized carbonate (ST-LMNCO) demonstrated an improved volume density of similar to 14% compared to the one derived from the co-precipitated synthesized carbonate (CP-LMNCO). As for electrochemical performances, the ST-LMNCO exhibited a higher discharge specific capacitance (296.6mA h g(-1) for the first discharge), a better rate performance (201.6 mA h g(-1) at 1C rate) and a better capacity retention capability (86.2% after 80 cycles) than the CP-LMNCO. The morphologies of the transition metal carbonates as starting materials significantly impacted the morphologies of the derived Li-1.2Mn0.54Ni0.13Co0.13O2 particles. Therefore, the carbonate with a hierarchical micro-nanostructure obtained from the solvothermal method is a promising precursor for high performance Li1.2Mn0.Ni-54(0).13Co0.13O2.</p
Li-Yorke chaos for maps on G-Spaces
Full text linkWe introduce the definition of Li-Yorke chaos for the map f on G-spaces, and show G-Li-Yorke chaos is iterable for f. Li-Yorke chaos implies G-Li-Yorke chaos, while the converse is not true. Then we give a sufficient condition for f to be chaotic in the sense of G-Li-Yorke. Also, we prove that if f is G-transitive and there exists a common fixed point for f and all of the maps in G, then f is chaotic in the sense of G-Li-Yorke
TiF<sub>3</sub> catalyzed MgH<sub>2</sub> as a Li/Na ion battery anode
No full textMgH2 has been considered as a potential anode material for Li ion batteries due to its low cost and high theoretical capacity. However, it suffers from low electronic conductivity and slow kinetics for hydrogen sorption at room temperature that results in poor reversibility, cycling stability and rate capability for Li ion storage. This work presents a MgH2–TiF3@CNT based Li ion battery anode manufactured via a conventional slurry based method. Working with a liquid electrolyte at room temperature, it achieves a high capacity retention of 543 mAh g−1 in 70 cycles at 0.2 C and an improved rate capability, thanks to the improved hydrogen sorption kinetics with the presence of catalytic TiF3. Meanwhile, the first realization of Na ion uptake in MgH2 has been evidenced in experiments.Accepted Author ManuscriptChemE/Materials for Energy Conversion and Storag
Structural Changes in Li2MnO3 Cathode Material for Li-Ion Batteries
No full textStructural changes in Li2MnO3 cathode material for rechargeable Li-ion batteries are investigated during the first and 33 rd cycles. It is found that both the participation of oxygen anions in redox processes and Li+-H+ exchange play an important role in the electrochemistry of Li2MnO3. During activation, oxygen removal from the material along with Li gives rise to the formation of a layered MnO2-type structure, while the presence of protons in the interslab region, as a result of electrolyte oxidation and Li+-H+ exchange, alters the stacking sequence of oxygen layers. Li re-insertion by exchanging already present protons reverts the stacking sequence of oxygen layers. The re-lithiated structure closely resembles the parent Li2MnO3, except that it contains less Li and O. Mn4+ ions remain electrochemically inactive at all times. Irreversible oxygen release occurs only during activation of the material in the first cycle. During subsequent cycles, electrochemical processes seem to involve unusual redox processes of oxygen anions of active material along with the repetitive, irreversible oxidation of electrolyte species. The deteriorating electrochemical performance of Li2MnO3 upon cycling is attributed to the structural degradation caused by repetitive shearing of oxygen layers. Structural changes in Li2MnO3 provide evidence for the unusual electrochemical processes such as Li+-H+ exchange and the participation of oxygen anions in redox reactions. The observed decline in the electrochemical performance of the material upon cycling, mainly attributed to the Li+-H+ exchange and associated structural changes, also provides a global explanation for the reported cycling behavior of Li2MnO3-containing Li-rich cathode materials. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Synthesis and characterisation of Li-modified g-C3N4
No full textGraphitic carbon nitride (g-C3N4) is of great interest in photolysis. However, g-C3N4 suffers from a fast recombination rate of photogenerated electron and hole (e-/h+ ) pairs. It is hypothesised that surface modification of g-C3N4 with alkali metals is able to suppress the recombination rate of photogenerated e-/h+ pairs. Hence, in the present research, a series of lithium modified g-C3N4 (xLi/g-C3N4 (x = 2.7, 5.0 and 9.0 wt%)) nanocomposites were synthesised by impregnating g-C3N4 with LiOH. The synthesised nanocomposites were characterised using x-ray powder diffraction (XRD), inductive coupled plasma mass spectroscopy (ICP-MS), scanning electron microscopy (SEM), uv–vis diffuse reflectance spectroscopy (DRS UV–Vis), high resolution electron microscopy (HRTEM), photoluminescence (PL), Fourier transform infrared (FT-IR) and thermogravimetric (TGA) analyses. The TGA analysis showed that the thermal stability of the Li/g-C3N4 decreased compared to g-C3N4 due to the enlarged interlayer distance over g-C3N4. The XRD analysis indicates that a larger distance of the in-planar structure motif of g-C3N4 downshifted the (0 0 2) diffraction line of the g-C3N4 from 27.60 to 26.83 and weakened its intensity after doping. Increasing the Li+ concentration transformed the Li/g-C3N4 into a disordered graphite nanocomposite. The IR peak intensity at 2174 cm1 associated with the defect terminal –C-N increased when the Li+ concentration was increased, indicating that the incorporation of Li+ reduced the degree of melamine condensation and formed g-C3N4 with more defect sites. The HRTEM images showed that the g-C3N4 thin nanosheet structure became uneven and wrinkled after doping. Rock-like particles were observed when the Li+ concentration exceeds 5 wt% Li/g-C3N4. Similar rock-like and plate-like particles with voids were observable in the nanocomposites’ SEM images. The UV–Vis analysis indicates that Li+ doping reduced visible light sensitivity of the Li/g-C3N4 nanocomposites compared to g-C3N4, possibly due to the distortion of the g-C3N4 planar structure. The PL analysis indicates that the photogenerated recombination rate e-/h+ pairs were suppressed even though the sensitivity towards visible light decreased
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