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  • 1
    Language: English
    In: Proceedings of the National Academy of Sciences of the United States of America, 25 October 2011, Vol.108(43), pp.17696-701
    Description: The adult Drosophila copper cell region or "stomach" is a highly acidic compartment of the midgut with pH 〈 3. In this region, a specialized group of acid-secreting cells similar to mammalian gastric parietal cells has been identified by a unique ultrastructure and by copper-metallothionein fluorescence. However, the homeostatic mechanism maintaining the acid-secreting "copper cells" of the adult midgut has not been examined. Here, we combine cell lineage tracing and genetic analysis to investigate the mechanism by which the gastric epithelium is maintained. Our investigation shows that a molecularly identifiable population of multipotent, self-renewing gastric stem cells (GSSCs) produces the acid-secreting copper cells, interstitial cells, and enteroendocrine cells of the stomach. Our assays demonstrate that GSSCs are largely quiescent but can be induced to regenerate the gastric epithelium in response to environmental challenge. Finally, genetic analysis reveals that adult GSSC maintenance depends on Wnt signaling. Characterization of the GSSC lineage in Drosophila, with striking similarities to mammals, will advance the study of both homeostatic and pathogenic processes in the stomach.
    Keywords: Drosophila ; Gastric Mucosa -- Cytology ; Gastrointestinal Tract -- Cytology ; Multipotent Stem Cells -- Cytology ; Signal Transduction -- Physiology
    ISSN: 00278424
    E-ISSN: 1091-6490
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  • 2
    Language: English
    In: Journal of Business Ethics, 2014, Vol.123(4), pp.687-706
    Description: Strategic leadership and corporate sustainability have recently come together in conspicuously explicit fashion through the emergence of top management team (TMT) positions with dedicated corporate sustainability responsibilities. These TMT positions, commonly referred to as “Chief Sustainability Officers,” have found their way into the upper echelons of many of the world’s largest corporations alongside more traditional TMT positions including the CEO and CFO. We explore this phenomenon and consider the following two questions: Why are corporate sustainability positions being installed to the TMT? What effects do corporate sustainability TMT positions have at their organizations? We consider these questions through strategic leadership and neoinstitutional theoretical frameworks. Through the latter, we also engage with Weberian considerations of bureaucracy. We find that the reasons why corporate sustainability TMT positions are installed can be in response to a crisis at the corporation for which its legitimacy is challenged. We also find the corporate sustainability TMT position can be installed proactively in an effort to realize external opportunities that may have otherwise gone unrealized without concerted attention and coordination afforded by a strategic level position. Regarding effects, we determine the position can relate to the establishment of bureaucratic structures dedicated to corporate sustainability within the corporation through which formalized processes and key performance indicators to drive corporate sustainability performances are established. In the face of our finding that many corporate sustainability TMT positions are being removed despite having only relatively recently been introduced to their respective TMTs, we find that the successful implementation of bureaucratic machinery can help considerations to sustainability extend beyond the tenure of a corporate sustainability position within the TMT.
    Keywords: Chief Sustainability Officer ; Strategic Leadership ; Corporate sustainability ; Top management team
    ISSN: 0167-4544
    E-ISSN: 1573-0697
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  • 3
    Language: English
    In: ELH, Spring, 2013, Vol.80(1), p.287-316
    Description: Henderson the rain King exchanges the concept of a Jewish political alliance with blacks for a model of liberated professionalism and opposes the concept of collective movements for social change. where africa is concerned, the novel moves beyond static...
    Keywords: Globalization -- Social Aspects ; Imperialism -- Analysis ; Social Change -- Planning
    ISSN: 0013-8304
    E-ISSN: 10806547
    Source: Cengage Learning, Inc.
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  • 4
    Language: English
    In: Journal of Business Ethics, 2015, Vol.127(1), pp.107-107
    Description: Byline: Robert Strand (1) Author Affiliation: (1) Copenhagen Business School, Copenhagen, Denmark Article History: Registration Date: 27/08/2013 Online Date: 10/09/2013 Article note: The online version of the original article can be found under doi: 10.1007/s10551-013-1793-0. The online version of the original article can be found at http://dx.doi.org/10.1007/s10551-013-1793-0.
    Keywords: Philosophy ; Ethics ; Business/Management Science, General ; Management/Business for Professionals ; Non-Profit Enterprises/Corporate Social Responsibility ; Quality of Life Research ; Business ; Philosophy ; Law;
    ISSN: 0167-4544
    E-ISSN: 1573-0697
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  • 5
    Language: English
    In: Science (New York, N.Y.), 11 June 2010, Vol.328(5984), pp.1368-9
    Description: Order parameter symmetry is one of the basic characteristics of a superconductor. The heavy fermion compound UPt3 provides a rich system for studying the competition between superconductivity and other forms of electronic order and exhibits two distinct superconducting phases that are characterized by different symmetries. We fabricated a series of Josephson tunnel junctions on the as-grown surfaces of UPt3 single crystals spanning the a-b plane. By measuring their critical current, we mapped out the magnitude of the superconducting order parameter as a function of the momentum-space direction and temperature. In the high-temperature phase, we observed a sharp node in the superconducting gap at 45 degrees with respect to the a axis; an out-of-phase component appeared in the low-temperature phase, creating a complex order parameter.
    Keywords: Superconductors -- Research ; Fermions -- Properties ; Superconductivity -- Observations;
    ISSN: 00368075
    E-ISSN: 1095-9203
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  • 6
    Language: English
    In: Proceedings of the National Academy of Sciences of the United States of America, 21 April 2015, Vol.112(16), pp.5057-62
    Description: Mosquitoes are major disease vectors because most species must feed on blood from a vertebrate host to produce eggs. Blood feeding by the vector mosquito Aedes aegypti triggers the release of two neurohormones, ovary ecdysteroidogenic hormone (OEH) and insulin-like peptides (ILPs), which activate multiple processes required for egg formation. ILPs function by binding to the insulin receptor, which activates downstream components in the canonical insulin signaling pathway. OEH in contrast belongs to a neuropeptide family called neuroparsins, whose receptor is unknown. Here we demonstrate that a previously orphanized receptor tyrosine kinase (RTK) from A. aegypti encoded by the gene AAEL001915 is an OEH receptor. Phylogenetic studies indicated that the protein encoded by this gene, designated AAEL001915, belongs to a clade of RTKs related to the insulin receptor, which are distinguished by an extracellular Venus flytrap module. Knockdown of AAEL001915 by RNAi disabled OEH-mediated egg formation in A. aegypti. AAEL001915 was primarily detected in the mosquito ovary in association with follicular epithelial cells. Both monomeric and dimeric AAEL001915 were detected in mosquito ovaries and transfected Drosophila S2 cells. Functional assays further indicated that OEH bound to dimeric AAEL001915, which resulted in downstream phosphorylation of Ak strain transforming factor (Akt). We hypothesize that orthologs of AAEL001915 in other insects are neuroparsin receptors.
    Keywords: Insect ; Mosquito ; Oogenesis ; Reproduction ; Vector ; Oogenesis ; Aedes -- Enzymology ; Ecdysteroids -- Metabolism ; Insect Proteins -- Metabolism ; Ovary -- Enzymology ; Receptor Protein-Tyrosine Kinases -- Metabolism
    ISSN: 00278424
    E-ISSN: 1091-6490
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  • 7
    Language: English
    In: Physical Review B, 2014, Vol.90(15)
    Description: We show that repulsive local Coulomb interaction alone can drive valence-skipping charge disproportionation in the degenerate d-band, resulting in effective negative-U. This effect is shown to originate from anisotropic orbital-multipole scattering, and it occurs only for d(1), d(4), d(6), and d(9) fillings...
    Keywords: Fysik ; Physical Sciences ; Hartree-Fock ; Systems ; Oxides ; Model ; Physics ; Condensed Matter
    ISSN: 1098-0121
    E-ISSN: 1550235X
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  • 8
    Language: English
    In: Proceedings of the National Academy of Sciences of the United States of America, 13 April 2015, Vol.112(17)
    Description: Cyclic electron flow (CEF) around photosystem I is thought to balance the ATP/NADPH energy budget of photosynthesis, requiring that its rate be finely regulated. The mechanisms of this regulation are not well understood. We observed that mutants that exhibited constitutively high rates of CEF also showed elevated production of H2O2. We thus tested the hypothesis that CEF can be activated by H2O2 in vivo. CEF was strongly increased by H2O2 both by infiltration or in situ production by chloroplast-localized glycolate oxidase, implying that H2O2 can activate CEF either directly by redox modulation of key enzymes, or indirectly by affecting other photosynthetic processes. CEF appeared with a half time of about 20 min after exposure to H2O2, suggesting activation of previously expressed CEF-related machinery. H2O2-dependent CEF was not sensitive to antimycin A or loss of PGR5, indicating that increased CEF probably does not involve the PGR5-PGRL1 associated pathway. In contrast, the rise in CEF was not observed in a mutant deficient in the chloroplast NADPH:PQ reductase (NDH), supporting the involvement of this complex in CEF activated by H2O2. In conclusion, we propose that H2O2 is a missing link between environmental stress, metabolism, and redox regulation of CEF in higher plants.
    Keywords: Inorganic, Organic, Physical, And Analytical Chemistry ; Cyclic Electron Flow ; Photosynthesis ; Reactive Oxygen Species ; Stress ; Hydrogen Peroxide ; Sciences (General)
    ISSN: 0027-8424
    E-ISSN: 1091-6490
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  • 9
    Language: English
    In: Hydrobiologia, 2013, Vol.709(1), pp.227-235
    Description: The vital roles that sponges play in marine habitats are well-known. However, sponges inhabiting freshwaters have been largely ignored despite having widespread distributions and often high local abundances. We used natural abundance stable isotope signatures of carbon and nitrogen ( δ 13 C and δ 15 N) to infer the primary food source of the cosmopolitan freshwater sponge Spongilla lacustris . Our results suggest that S. lacustris feed largely on pelagic resources and may therefore link pelagic and benthic food webs. A facultative association between S. lacustris and endosymbiotic green algae caused S. lacustris to have significantly depleted carbon and nitrogen signatures that may reflect carbon and nitrogen exchange between sponges and their symbiotic algae. Isotopic data from specialist sponge consumers demonstrated that sponges hosting zoochlorellae were the major component of the diet of the spongillafly Climacia areolaris and the sponge-eating caddisfly Ceraclea resurgens suggesting that the symbiosis between freshwater sponges and algae is important to sponge predator trophic ecology. Our results help define the role of sponges in freshwater ecosystems and shed new light on the evolution and ecological consequences of a complex tri-trophic symbiosis involving freshwater sponges, zoochlorellae, and spongivorous insects.
    Keywords: Food webs ; Energy flow ; Symbiosis ; Zoochlorellae ; Sisyridae ; Ceraclea ; Sponge predators
    ISSN: 0018-8158
    E-ISSN: 1573-5117
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  • 10
    Language: English
    In: Annals of the Rheumatic Diseases, June, 2014, Vol.73(6), p.18(1)
    Keywords: Rheumatoid Arthritis -- Risk Factors ; Radiography -- Usage ; Magnetic Resonance Imaging -- Usage ; Doppler Ultrasonography -- Usage
    ISSN: 0003-4967
    Source: Cengage Learning, Inc.
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