601 research outputs found
Democratic Orators from JFK to Barack Obama
How do leading Democratic Party figures strive to communicate with and influence their audience? Why have some proven more successful than others in advancing their ideological arguments? How do orators seek to connect with different audiences in different settings such as the Senate, conventions and through the media? This thoroughly researched and highly readable collection comprehensively evaluates these questions as well as providing an extensive interrogation of the political and intellectual significance of oratory and rhetoric in the Democratic Party. Using the Aristotelian modes of persuasion ethos, pathos and logos it draws out commonalties and differences in how the rhetoric of Democratic Party politics has shifted since the 1960s. More broadly it evaluates the impact of leading orators upon American politics and argues that effective oratory remains a vital party of American political discourse
When, If Ever, Should Trials Be Held Behind Closed Doors?
In Gannett Co. v. DePasquale Justice Stewart framed the issue before the United States Supreme Court as follows: [W]hether members of the public have an independent constitutional right [under the sixth amendment] to insist upon access to a pretrial judicial proceeding, even though the accused, the prosecutor and the trial judge all have agreed to the closure of that proceeding in order to assure a fair trial
The patient experience movement moment
For years, the patient experience movement has continued to gain momentum. From a novel concept, there is an emerging consensus that the patient experience is a fundamental aspect of provider quality; one that complements established clinical process and outcome measures but is neither subsumed nor secondary to them. An increasing volume of research as encouraged by publications such as Patient Experience Journal show this to be true. As the expectation of a high-quality patient experience becomes the norm, these developments have brought us to what we call the patient experience movement moment and there is little doubt that the patient experience has become, and is poised to remain, a central concern in healthcare for many years to come
Acylation of glucosaminyl phosphatidylinositol revisited. Palmitoyl-CoA dependent palmitoylation of the inositol residue of a synthetic dioctanoyl glucosaminyl phosphatidylinositol by hamster membranes permits efficient mannosylation of the glucosamine residue
Two critical steps in the assembly of yeast and mammalian glycosylphosphatidylinositol (GPI) anchor precursors are palmitoylation of the inositol residue and mannosylation of the glucosamine residue of the glucosaminyl phosphatidylinositol (GlcNα-PI) intermediate. Palmitoylation has been reported to be acyl-CoA dependent in yeast membranes (Costello, L. C., and Orlean, P. (1992) J. Biol. Chem. 267, 8599-8603) but strictly acyl- CoA independent in rodent membranes (Stevens, V. L., and Zhang, H. (1994) J. Biol. Chem. 269, 31397-31403), and thus poorly conserved. In addition, it was suggested that acylation must precede mannosylation in both yeast (Costello, L. C., and Orlean, P. (1992) J. Biol. Chem. 276, 8599-8603) and rodent (Urakaze, M., Kamitani, T., DeGasperi, R., Sugiyama, E., Chang, H.-M., Warren, C. D., and Yeh, E. T. H. (1992) J. Biol. Chem. 267, 6459-6462) cells because GlcNα-acyl-PI accumulates in vivo when mannosylation is blocked. However, GlcNα-acyl-PI accumulation would also be expected if mannosylation and acylation were independent of each other. These issues were addressed by the use of a synthetic dioctanoyl GlcNα-PI analogue (GlcNα-PI(C8)) as an in vitro substrate for GPI-synthesizing enzymes in Chinese hamster ovary cell membranes. GlcNα-PI(C8) was acylated in an manner requiring acyl-CoA. Thus, the process involving acyl-CoA reported for yeast has been conserved in mammals. Furthermore, both GlcNα-PI(C8) and GlcNα-acyl-PI(C8) could be mannosylated in vitro, but mannosylation of the latter was significantly more efficient. This provides direct support for the earlier suggestion that acylation precedes mannosylation in rodents cells. A similar result was also observed with the Saccharomyces cerevisiae mannosyltransferase. In contrast, it has been reported that mannosylation of endogenous GlcNα-PI by Trypansoma brucei membranes occurs without prior acylation. The same result was obtained with GlcNα-PI(C8), confirming that the mannosyltransferase of trypanosomes is divergent from those in yeasts and rodents
Working with simple machines
A set of examples is provided that illustrate the use of work as applied to
simple machines. The ramp, pulley, lever and hydraulic press are common
experiences in the life of a student and their theoretical analysis therefore
makes the abstract concept of work more real. The mechanical advantage of each
of these systems is also discussed so that students can evaluate their
usefulness as machines.Comment: 9 pages, 4 figure
Translation attenuation by PERK balances ER glycoprotein synthesis with lipid-linked oligosaccharide flux
Endoplasmic reticulum (ER) homeostasis requires transfer and subsequent processing of the glycan Glc3Man9GlcNAc2 (G3M9Gn2) from the lipid-linked oligosaccharide (LLO) glucose3mannose9N-acetylglucosamine2-P-P-dolichol (G3M9Gn2-P-P-Dol) to asparaginyl residues of nascent glycoprotein precursor polypeptides. However, it is unclear how the ER is protected against dysfunction from abnormal accumulation of LLO intermediates and aberrant N-glycosylation, as occurs in certain metabolic diseases. In metazoans phosphorylation of eukaryotic initiation factor 2α (eIF2α) on Ser51 by PERK (PKR-like ER kinase), which is activated by ER stress, attenuates translation initiation. We use brief glucose deprivation to simulate LLO biosynthesis disorders, and show that attenuation of polypeptide synthesis by PERK promotes extension of LLO intermediates to G3M9Gn2-P-P-Dol under these substrate-limiting conditions, as well as counteract abnormal N-glycosylation. This simple mechanism requires eIF2α Ser51 phosphorylation by PERK, and is mimicked by agents that stimulate cytoplasmic stress-responsive Ser51 kinase activity. Thus, by sensing ER stress from defective glycosylation, PERK can restore ER homeostasis by balancing polypeptide synthesis with flux through the LLO pathway
Cytosolic Nuclease TREX1 Regulates Oligosaccharyltransferase Activity Independent of Nuclease Activity to Suppress Immune Activation
SummaryTREX1 is an endoplasmic reticulum (ER)-associated negative regulator of innate immunity. TREX1 mutations are associated with autoimmune and autoinflammatory diseases. Biallelic mutations abrogating DNase activity cause autoimmunity by allowing immunogenic self-DNA to accumulate, but it is unknown how dominant frameshift (fs) mutations that encode DNase-active but mislocalized proteins cause disease. We found that the TREX1 C terminus suppressed immune activation by interacting with the ER oligosaccharyltransferase (OST) complex and stabilizing its catalytic integrity. C-terminal truncation of TREX1 by fs mutations dysregulated the OST complex, leading to free glycan release from dolichol carriers, as well as immune activation and autoantibody production. A connection between OST dysregulation and immune disorders was demonstrated in Trex1−/− mice, TREX1-V235fs patient lymphoblasts, and TREX1-V235fs knock-in mice. Inhibiting OST with aclacinomycin corrects the glycan and immune defects associated with Trex1 deficiency or fs mutation. This function of the TREX1 C terminus suggests a potential therapeutic option for TREX1-fs mutant-associated diseases
Mannose-6-phosphate regulates destruction of lipid-linked oligosaccharides.
Mannose-6-phosphate (M6P) is an essential precursor for mannosyl glycoconjugates, including lipid-linked oligosaccharides (LLO; glucose(3)mannose(9)GlcNAc(2)-P-P-dolichol) used for protein N-glycosylation. In permeabilized mammalian cells, M6P also causes specific LLO cleavage. However, the context and purpose of this paradoxical reaction are unknown. In this study, we used intact mouse embryonic fibroblasts to show that endoplasmic reticulum (ER) stress elevates M6P concentrations, leading to cleavage of the LLO pyrophosphate linkage with recovery of its lipid and lumenal glycan components. We demonstrate that this M6P originates from glycogen, with glycogenolysis activated by the kinase domain of the stress sensor IRE1-α. The apparent futility of M6P causing destruction of its LLO product was resolved by experiments with another stress sensor, PKR-like ER kinase (PERK), which attenuates translation. PERK's reduction of N-glycoprotein synthesis (which consumes LLOs) stabilized steady-state LLO levels despite continuous LLO destruction. However, infection with herpes simplex virus 1, an N-glycoprotein-bearing pathogen that impairs PERK signaling, not only caused LLO destruction but depleted LLO levels as well. In conclusion, the common metabolite M6P is also part of a novel mammalian stress-signaling pathway, responding to viral stress by depleting host LLOs required for N-glycosylation of virus-associated polypeptides. Apparently conserved throughout evolution, LLO destruction may be a response to a variety of environmental stresses.This work is supported by NIH grants DK-042394, HL-052173, and HL-057346 to R.J.K.; by NIH grants AI-073898 and GM-056927 to I.M.; by NIH grant R-37-DK047119 and a Principal Research Fellowship from the Wellcome Trust to D.R.; by NIH grant GM-031278 and support from the Robert Welch Foundation to J.R.F.; and by NIH grant GM-038545 and Robert Welch Foundation grant I-1168 to M.A.L
Potential effects of oilseed rape expressing oryzacystatin-1 (OC-1) and of purified insecticidal proteins on larvae of the solitary bee Osmia bicornis
Despite their importance as pollinators in crops and wild plants, solitary bees have not previously been included in non-target testing of insect-resistant transgenic crop plants. Larvae of many solitary bees feed almost exclusively on pollen and thus could be highly exposed to transgene products expressed in the pollen. The potential effects of pollen from oilseed rape expressing the cysteine protease inhibitor oryzacystatin-1 (OC-1) were investigated on larvae of the solitary bee Osmia bicornis (= O. rufa). Furthermore, recombinant OC-1 (rOC-1), the Bt toxin Cry1Ab and the snowdrop lectin Galanthus nivalis agglutinin (GNA) were evaluated for effects on the life history parameters of this important pollinator. Pollen provisions from transgenic OC-1 oilseed rape did not affect overall development. Similarly, high doses of rOC-1 and Cry1Ab as well as a low dose of GNA failed to cause any significant effects. However, a high dose of GNA (0.1%) in the larval diet resulted in significantly increased development time and reduced efficiency in conversion of pollen food into larval body weight. Our results suggest that OC-1 and Cry1Ab expressing transgenic crops would pose a negligible risk for O. bicornis larvae, whereas GNA expressing plants could cause detrimental effects, but only if bees were exposed to high levels of the protein. The described bioassay with bee brood is not only suitable for early tier non-target tests of transgenic plants, but also has broader applicability to other crop protection products
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