725 research outputs found

    Modernity, Melancholy, Memory, and Filth: New Perspectives on Russian and Soviet Cities

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    The Man Question: How Bolshevik Masculinity Shaped International Communism

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    It was a communist romance. In 1923, Croatian American communist Steve Nelson (born Stjepan Mesarsoơ) met Margaret Yeager, the daughter of ‘radical’ German immigrants, at the Communist Party office in Pittsburgh. As Nelson recalled in his 1981 memoir, ‘everything happened’ very quickly, and the two married the same year. Both understood that Yeager, the ‘better educated’ and ‘more sophisticated’ of the two, would not accept a ‘passive role’ in the relationship. Indeed her mother gave the nineteen-year-old bridegroom a copy of August Bebel’s Woman and Socialism as a wedding gift. Nonetheless, they soon took on stereotypical roles. He became an important activist, while she ‘tailor[ed] her life to what was required of me’. Recognising that an outsider might ‘conclude 
 that Maggie accepted a traditional female role because she shared the accepted view of a “woman’s place” at the time’, Nelson assured his readers that she did not: ‘As a revolutionary she consciously gave me all the breaks, feeling this would be best for the movement’. Thus a self-consciously revolutionary union produced a paradoxically traditional marriage

    Airports at Risk: The Impact of Information Sources on Security Decisions

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    Security decisions in high risk organizations such as airports involve obtaining ongoing and frequent information about potential threats. Utilizing questionnaire survey data from a sample of airport employees in European Airports across the continent, we analyzed how both formal and informal sources of security information affect employee's decisions to comply with the security rules and directives. This led us to trace information network flows to assess its impact on the degree employees making security decisions comply or deviate with the prescribed security rules. The results of the multivariate analysis showed that security information obtained through formal and informal networks differentially determine if employee will comply or not with the rules. Information sources emanating from the informal network tends to encourage employees to be more flexible in their security decisions while formal sources lead to be more rigid with complying with rules and protocols. These results suggest that alongside the formal administrative structure of airports, there exists a diverse and pervasiveness set of informal communications networks that are a potent factor in determining airport security levels

    Coffee Stirrers and Drinking Straws as Disposable Spatulas

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    While metal spatulas are damaged through everyday use and become discolored and corroded by chemical exposure, drinking straws are inexpensive and disposable, reducing the risk of cross contamination during laboratory experiments. Drinking straws are also useful because they come in a variety of sizes; narrow sample containers such as NMR and EPR tubes can easily be filled using small diameter coffee stirrers, while bulk material can be transferred using larger drinking straws. Several types of drinking straws and coffee stirrers were cut at various angles and the amount of material picked up in a single scoop was massed thirty times. Standard deviations of the thirty measurements per straw indicate that approximately the same amount of material will be scooped each time by the same operator

    Glucitol-core containing gallotannins inhibit the formation of advanced glycation end-products mediated by their antioxidant potential

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    Glucitol-core containing gallotannins (GCGs) are polyphenols containing galloyl groups attached to a 1,5-anhydro-D-glucitol core, which is uncommon among naturally occurring plant gallotannins. GCGs have only been isolated from maple (Acer) species, including the red maple (Acer rubrum), a medicinal plant which along with the sugar maple (Acer saccharum), are the major sources of the natural sweetener, maple syrup. GCGs are reported to show antioxidant, α-glucosidase inhibitory, and antidiabetic effects, but their antiglycating potential is unknown. Herein, the inhibitory effects of five GCGs (containing 1–4 galloyls) on the formation of advanced glycation end-products (AGEs) were evaluated by MALDI-TOF mass spectroscopy, and BSA–fructose, and G.K. peptide-ribose assays. The GCGs showed superior activities compared to the synthetic antiglycating agent, aminoguanidine (IC50 15.8–151.3 vs. \u3e300 ÎŒM) at the early, middle, and late stages of glycation. Circular dichroism data revealed that the GCGs were able to protect the secondary structure of BSA protein from glycation. The GCGs did not inhibit AGE formation by the trapping of reactive carbonyl species, namely, methylglyoxal, but showed free radical scavenging activities in the DPPH assay. The free radical quenching properties of the GCGs were further confirmed by electron paramagnetic resonance spectroscopy using ginnalin A (contains 2 galloyls) as a representative GCG. In addition, this GCG chelated ferrous iron, an oxidative catalyst of AGE formation, supported a potential antioxidant mechanism of antiglycating activity for these polyphenols. Therefore, GCGs should be further investigated for their antidiabetic potential given their antioxidant, α-glucosidase inhibitory, and antiglycating properties

    Superfluid Density and Field-Induced Magnetism in Ba(Fe1-xCox)2As2 and Sr(Fe1-xCox)2As2 Measured with Muon Spin Relaxation

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    We report muon spin rotation (ÎŒ\muSR) measurements of single crystal Ba(Fe1−x_{1-x}Cox_x)2_2As2_2 and Sr(Fe1−x_{1-x}Cox_x)2_2As2_2. From measurements of the magnetic field penetration depth λ\lambda we find that for optimally- and over-doped samples, 1/λ(T→0)21/\lambda(T\to 0)^2 varies monotonically with the superconducting transition temperature TC_{\rm C}. Within the superconducting state we observe a positive shift in the muon precession signal, likely indicating that the applied field induces an internal magnetic field. The size of the induced field decreases with increasing doping but is present for all Co concentrations studied.Comment: 7 pages, accepted for publication in Phys. Rev.

    Anti-glycation and anti-oxidative effects of a phenolic-enriched maple syrup extract and its protective effects on normal human colon cells

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    Oxidative stress and free radical generation accelerate the formation of advanced glycation endproducts (AGEs) which are linked to several chronic diseases. Published data suggest that phenolic-rich plant foods, show promise as natural anti-AGEs agents due to their anti-oxidation capacities. A phenolic-enriched maple syrup extract (MSX) has previously been reported to show anti-inflammatory and neuroprotective effects but its anti-AGE effects remain unknown. Therefore, herein, we investigated the anti-glycation and anti-oxidation effects of MSX using biochemical and biophysical methods. MSX (500 ÎŒg mL−1) reduced the formation of AGEs by 40% in the bovine serum albumin (BSA)–fructose assay and by 30% in the BSA–methylglyoxal (MGO) assay. MSX also inhibited the formation of crosslinks typically seen in the late stage of glycation. Circular dichroism and differential scanning calorimeter analyses demonstrated that MSX maintained the structure of BSA during glycation. In the anti-oxidant assays, MSX (61.7 ÎŒg mL−1) scavenged 50% of free radicals (DPPH assay) and reduced free radical generation by 20% during the glycation process (electron paramagnetic resonance time scan). In addition, the intracellular levels of hydrogen peroxide induced reactive oxygen species were reduced by 27–58% with MSX (50–200 ÎŒg mL−1) in normal/non-tumorigenic human colon CCD-18Co cells. Moreover, in AGEs and MGO challenged CCD-18Co cells, higher cellular viabilities and rapid extracellular signal-regulated kinase (ERK) phosphorylation were observed in MSX treated cells, indicating its protective effects against AGEs-induced cytotoxicity. Overall, this study supports the biological effects of MSX, and warrants further investigation of its potential as a dietary agent against diseases mediated by oxidative stress and inflammation

    Time-resolved single-cell RNA-seq using metabolic RNA labelling

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    Single-cell RNA sequencing offers snapshots of whole transcriptomes but obscures the temporal RNA dynamics. Here we present single-cell metabolically labeled new RNA tagging sequencing (scNT-seq), a method for massively parallel analysis of newly transcribed and pre-existing mRNAs from the same cell. This droplet microfluidics-based method enables high-throughput chemical conversion on barcoded beads, efficiently marking newly transcribed mRNAs with T-to-C substitutions. Using scNT-seq, we jointly profiled new and old transcriptomes in ~55,000 single cells. These data revealed time-resolved transcription factor activities and cell-state trajectories at the single-cell level in response to neuronal activation. We further determined rates of RNA biogenesis and decay to uncover RNA regulatory strategies during stepwise conversion between pluripotent and rare totipotent two-cell embryo (2C)-like stem cell states. Finally, integrating scNT-seq with genetic perturbation identifies DNA methylcytosine dioxygenase as an epigenetic barrier into the 2C-like cell state. Time-resolved single-cell transcriptomic analysis thus opens new lines of inquiry regarding cell-type-specific RNA regulatory mechanisms

    Platelet and Neutrophil Responses to Gram Positive Pathogens in Patients with Bacteremic Infection

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    BACKGROUND: Many Gram-positive pathogens aggregate and activate platelets in vitro and this has been proposed to contribute to virulence. Platelets can also form complexes with neutrophils but little is however known about platelet and platelet-neutrophil responses in bacterial infection. METHODOLOGY/PRINCIPAL FINDINGS: We added isolates of Gram-positive bacteria from 38 patients with a bacteremic infection to blood drawn from the same patient. Aggregometry and flow cytometry were used to assess platelet aggregation and to quantify activation of platelets, neutrophils, and platelet-neutrophils complexes (PNCs) induced by the bacteria. Fifteen healthy persons served as controls. Most isolates of Staphylococcus aureus, beta hemolytic streptococci, and Enterococcus faecalis induced aggregation of platelets from their respective hosts, whereas pneumococci failed to do so. S. aureus isolates induced platelet aggregation more rapidly in patients than in controls, whereas platelet activation by S. aureus was lower in patients than in controls. PNCs were more abundant in baseline samples from patients than in healthy controls and most bacterial isolates induced additional PNC formation and neutrophil activation. CONCLUSION/SIGNIFICANCE: We have demonstrated for the first time that bacteria isolated from patients with Gram-positive bacteremia can induce platelet activation and aggregation, PNC formation, and neutrophil activation in the same infected host. This underlines the significance of these interactions during infection, which could be a target for future therapies in sepsis

    From Bitstreams to Heritage: Putting Digital Forensics into Practice in Collecting Institutions

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    This paper examines the application of digital forensics methods to materials in collecting institutions – particularly libraries, archives and museums. It discusses motivations, challenges, and emerging strategies for the use of these technologies and workflows. It is a product of the BitCurator project. The BitCurator project began on October 1, 2011, through funding from the Andrew W. Mellon Foundation. BitCurator is an effort to build, test, and analyze systems and software for incorporating digital forensics methods into the workflows of a variety of collecting institutions. It is led by the School of Information and Library Science (SILS) at the University of North Carolina, Chapel Hill and the Maryland Institute for Technology in the Humanities (MITH) at the University of Maryland, and involves contributors from several other institutions. Two groups of external partners are contributing to this process: a Professional Expert Panel (PEP) of individuals who are at various levels of implementing digital forensics tools and methods in their collecting institution contexts, and a Development Advisory Group (DAG) of individuals who have significant experience with software development.2 This paper is a product of phase one of BitCurator (October 1, 2011 – September 30, 2013). The second phase of the project (October 1, 2013 – September 29, 2014) continues the development of the BitCurator environment, along with expanded professional engagement and community outreach activities
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