69 research outputs found
Sialic Acid Glycobiology Unveils Trypanosoma cruzi Trypomastigote Membrane Physiology.
Trypanosoma cruzi, the flagellate protozoan agent of Chagas disease or American trypanosomiasis, is unable to synthesize sialic acids de novo. Mucins and trans-sialidase (TS) are substrate and enzyme, respectively, of the glycobiological system that scavenges sialic acid from the host in a crucial interplay for T. cruzi life cycle. The acquisition of the sialyl residue allows the parasite to avoid lysis by serum factors and to interact with the host cell. A major drawback to studying the sialylation kinetics and turnover of the trypomastigote glycoconjugates is the difficulty to identify and follow the recently acquired sialyl residues. To tackle this issue, we followed an unnatural sugar approach as bioorthogonal chemical reporters, where the use of azidosialyl residues allowed identifying the acquired sugar. Advanced microscopy techniques, together with biochemical methods, were used to study the trypomastigote membrane from its glycobiological perspective. Main sialyl acceptors were identified as mucins by biochemical procedures and protein markers. Together with determining their shedding and turnover rates, we also report that several membrane proteins, including TS and its substrates, both glycosylphosphatidylinositol-anchored proteins, are separately distributed on parasite surface and contained in different and highly stable membrane microdomains. Notably, labeling for α(1,3)Galactosyl residues only partially colocalize with sialylated mucins, indicating that two species of glycosylated mucins do exist, which are segregated at the parasite surface. Moreover, sialylated mucins were included in lipid-raft-domains, whereas TS molecules are not. The location of the surface-anchored TS resulted too far off as to be capable to sialylate mucins, a role played by the shed TS instead. Phosphatidylinositol-phospholipase-C activity is actually not present in trypomastigotes. Therefore, shedding of TS occurs via microvesicles instead of as a fully soluble form
Integrating Time in Public Policy: Empirical Description of Gender-Specific Outcomes and Budgeting
The Impact of Financial Market Frictions on Trade Flows, Capital Flows and Economic Development
Data for: An estimate of the Average Cumulative Royalty Yield in the World Mobile Phone Industry
A New Dataset on Mobile Phone Patent License Royalties---August 2017 update
Mobile phones integrate a wide array of technologies, from computing to consumer electronics to communications, and from semiconductors to hardware, software and services. This makes them a relevant target for a large and broad array of patents and licensors. In addition, mobile phones rely on technological standards to make them interoperable. A standard-compliant phone uses hundreds, if not thousands of standard essential patents (SEPs), which are owned by many different patent holders.
While some have claimed that dispersed ownership of SEPs leads to high cumulative royalty rates, the estimates that underpin these claims are based on the simple addition of published handset royalty rates. This dataset estimates the Average Cumulative Patent Royalty Yield paid in the mobile phone value chain— the sum total of patent royalty payments earned by licensors, divided by the total value of mobile phones shipped. The core of our method, then, is to “follow the money.” In following the money, we make no distinctions as to where a licensor is earning revenues in the mobile phone value chain, nor do we make distinctions among the different patented technologies in a mobile phone. We capture, for example, revenues earned from licenses taken by semiconductor and base band chip producers, as well as the OEMs and EMSs that assemble phones. We also capture revenues earned from licenses on patents that enable video, imaging, audio, and other functions, as well as the SEPs that enable mobility. We capture, as well, the revenues of a major software company that earns revenue from its patents that read on the most popular mobile phone operating system.
Our purpose is to provide as comprehensive and transparent a data source as is practically possible for use by other researchers, industry practitioners, and government officials. We do not take a position on whether the estimates of the royalty yield we present in this study are “too high,” “too low,” or “just right.” That is an important debate, but it can only be joined on the basis of evidence.
All methods of analysis are dependent upon an underlying theory, and underlying theories are created in order to answer particular questions of interest. Calculating the cumulative royalties paid (or earned) in the mobile phone value chain is not an exception to this general rule. The basic question researchers are asking is how do royalties paid by firms in the mobile phone value chain affect production and decisions at the margin? That is, if royalty rates were X percent higher, by how much would output fall and prices increase? If they were X’ lower, by how much would output rise and prices fall? Microeconomic theory provides a guide to the relevant facts necessary to answer this question; it tells us that we need to approximate running royalties
Haloterrigena sp. SGH1: first extreme halophile Archaean isolated from Atacama halites
SME 16 Montreal, 16th International Symposium on Microbial Ecology; Montreal (Canada); 21-26 August 2016; http://www.isme-microbes.org/isme16Halites rocks (NaCl)) from Salar Grande, Atacama Desert, Chile, are rough substrates colonized by complex microbial consortia that include Eubacteria and Archaea representatives and are dominated by cyanobacteria from the Halothece genus, all unculturable microorganisms. Our purpose was to isolate and grow members of the community to learn on the underlying adaptive mechanisms of survival to the combined extreme environmental conditions (desiccation, high solar radiation, salinity) at Salar Grande, Atacama. Colonized fragments were dissolved in sterile Z8 liquid medium (20% salt, final concentration, 50 mM KCl, 10 mM compatible solutes: Lproline, trehalose or betaine) and incubated at 30°C. After 4 weeks, the liquid medium turned reddish and pigmented colonies were isolated in solid medium. Optimal growth conditions (salinity, pH, temperature, and potassium requirement), metabolic capabilities, molecular
taxonomy, pigment analysis and ultrastructural features were studied on the isolate. SGH1 is redpigmented coccus (1.2 µm mean diameter) with gas vesicles and a complex intracellular membrane network. Based on 16S rRNA gene sequences, SGH1 is an Archaean cell belonging to the Haloterrigena genus. SGH1 grew optimally at 25% w/v NaCl and 25 mM KCl. It also is a mesophile and neutrophile. We report the isolation, growth and characterization of the SGH1, the
first extreme halophilic, carotenoids-rich Archaean isolated from microbial consortia of Atacama halites that uses the salt-in strategy to cope with high external osmotic pressures.Acknowledgments: Grants CODEI-5394 and SI-5305 (Universidad de Antofagasta, Chile); FICR 4603 and CeBiB FB0001 (CONICYT, Chile); CGL2013-42509-P (Ministerio de Economía y Competitividad de España)
Could higher taxes increase the long-run demand for capital? Theory and evidence for Chile
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