1,749 research outputs found

    Navigating Tolkien’s Spatial Allegory

    Get PDF
    Tolkien’s vast and detailed legendarium has helped pave the way for the fantasy genre as we know it today. His wide variety of characters, detailed maps, and the rich history3 of Middle Earth have all undoubtedly provided inspiration to many modern writers, and continue to hold the interest of both new and old fans of his works. Within his world of Middle Earth, Tolkien has written about thousands of years’ worth of history, and has created for each of his imagined races its own culture and language. However, despite the unique differences of Middle Earth when compared to our own world, many of Tolkien’s key beliefs, such as his close ties to Christianity, have clearly manifested within his legendarium. While the inhabitants of Middle Earth operate under a divine system more like the Greek or Norse pantheon, there are clear Christian elements to his world. Even the physical landscape of Middle Earth, both in the early years of the First Age, and later on in the Third Age, seem to reflect the duality of the Christian concepts of good and evil. Tolkien seems to have set up a world in which intrinsically good things are closer to Heaven, and therefore closer to the Christian concept of God, whereas bad things often dwell underground, closer to the Christian ideas of Satan and Hell. Within the expanse of this spatial allegory that Tolkien has created, the residents of Middle Earth are able to move about in unique ways, and there seems to be a direct relationship between one’s physical elevation and their moral standing at that point in the story. This paper will seek to establish and analyze the allegory created within Tolkien’s legendarium, including its relationship to several key Christian elements, as well as observe a few specific instances of how character morality is directly reflected in their movement. By looking at character movements, and even the physical topography of Middle Earth, with Tolkien’s Christian beliefs in mind, readers can gain a greater understanding of the different ways Tolkien illustrates good and evil within his legendarium, as well as detect similarities between the ultimate fates of morally good and bad characters in the legendarium and keep figures in the Bible

    Step size of the rotary proton motor in single FoF1-ATP synthase from a thermoalkaliphilic bacterium by DCO-ALEX FRET

    Full text link
    Thermophilic enzymes can operate at higher temperatures but show reduced activities at room temperature. They are in general more stable during preparation and, accordingly, are considered to be more rigid in structure. Crystallization is often easier compared to proteins from bacteria growing at ambient temperatures, especially for membrane proteins. The ATP-producing enzyme FoF1-ATP synthase from thermoalkaliphilic Caldalkalibacillus thermarum strain TA2.A1 is driven by a Fo motor consisting of a ring of 13 c-subunits. We applied a single-molecule F\"orster resonance energy transfer (FRET) approach using duty cycle-optimized alternating laser excitation (DCO-ALEX) to monitor the expected 13-stepped rotary Fo motor at work. New FRET transition histograms were developed to identify the smaller step sizes compared to the 10-stepped Fo motor of the Escherichia coli enzyme. Dwell time analysis revealed the temperature and the LDAO dependence of the Fo motor activity on the single molecule level. Back-and-forth stepping of the Fo motor occurs fast indicating a high flexibility in the membrane part of this thermophilic enzyme.Comment: 14 pages, 7 figure

    Subunit rotation in single FRET-labeled F1-ATPase hold in solution by an anti-Brownian electrokinetic trap

    Full text link
    FoF1-ATP synthase catalyzes the synthesis of adenosine triphosphate (ATP). The F1 portion can be stripped from the membrane-embedded Fo portion of the enzyme. F1 acts as an ATP hydrolyzing enzyme, and ATP hydrolysis is associated with stepwise rotation of the gamma and epsilon subunits of F1. This rotary motion was studied in great detail for the last 15 years using single F1 parts attached to surfaces. Subunit rotation of gamma was monitored by videomicroscopy of bound fluorescent actin filaments, nanobeads or nanorods, or single fluorophores. Alternatively, we applied single-molecule F\"orster resonance energy transfer (FRET) to monitor subunit rotation in the holoenzyme FoF1-ATP synthase which was reconstituted in liposomes. Now we aim to extend the observation times of single FRET-labeled F1 in solution using a modified version of the anti-Brownian electrokinetic trap (ABELtrap) invented by A. E. Cohen and W. E. Moerner. We used Monte Carlo simulations to reveal that stepwise FRET efficiency changes can be analyzed by Hidden Markov Models even at the limit of a low signal-to-background ratio that was expected due to high background count rates caused by the microfluidics of the ABELtrap.Comment: 12 pages, 3 figure

    Propionibacterium spp. in prosthetic joint infections: a diagnostic challenge

    Get PDF
    Introduction: Propionibacterium species are common inhabitants of the skin and usually non-pathogenic for humans. However, Propionibacterium spp. can occasionally cause infections, but are estimated to play a minor role in prosthetic joint infections (PJI). The relative frequency of these anaerobes and their potential to cause surgical site infection may be clinically underestimated. An unknown proportion of these infections might be missed, since little is known about their clinical presentation, and since growth of Propionibacterium spp. in diagnostic samples is often interpreted as contamination. Thus, a hypothesis is being tested, stating that Propionibacterium spp. is not as rare as often reported, and it can cause severe soft-tissue damages in PJI. Materials and methods: In this retrospective analysis, we reviewed all PJI that had been treated in our institution from 2000 to 2005, and assessed the relative frequency of those caused by Propionibacterium spp. In the identified cases, features that led to the diagnosis (clinical, laboratory, radiological, microbiological and histopathological characteristics) were analysed. Results: Of 139 cases of prosthetic joint infections, 8(6%) were caused by Propionibacterium spp. Seven patients complained of pain as the main symptom, and four had damaged soft-tissue. Analysis of the diagnostic procedures showed a median of 39% positive samples out of all cultured biopsies (median 9.5 biopsies per case), with a median time-to-positivity of 8days. Results of histopathological examinations of the periprosthetic tissue correlated well with the clinical courses. Conclusions: Our data suggest that Propionibacterium associated prosthetic joint infections occur at a relative frequency that is comparable to many other pathogens. Clinical signs are generally subtle, but the spectrum includes also significant soft-tissue damages. In this study, a median of 9.5 biopsies per case, an incubation time of 14days, and the aid of histopathological examinations proved to be helpful in establishing the diagnosi

    Rationale and study design of the Prospective comparison of Angiotensin Receptor neprilysin inhibitor with Angiotensin receptor blocker MEasuring arterial sTiffness in the eldERly (PARAMETER) study.

    Get PDF
    Hypertension in elderly people is characterised by elevated systolic blood pressure (SBP) and increased pulse pressure (PP), which indicate large artery ageing and stiffness. LCZ696, a first-in-class angiotensin receptor neprilysin inhibitor (ARNI), is being developed to treat hypertension and heart failure. The Prospective comparison of Angiotensin Receptor neprilysin inhibitor with Angiotensin receptor blocker MEasuring arterial sTiffness in the eldERly (PARAMETER) study will assess the efficacy of LCZ696 versus olmesartan on aortic stiffness and central aortic haemodynamics

    Molecular quantum spin network controlled by a single qubit

    Full text link
    Scalable quantum technologies will require an unprecedented combination of precision and complexity for designing stable structures of well-controllable quantum systems. It is a challenging task to find a suitable elementary building block, of which a quantum network can be comprised in a scalable way. Here we present the working principle of such a basic unit, engineered using molecular chemistry, whose control and readout are executed using a nitrogen vacancy (NV) center in diamond. The basic unit we investigate is a synthetic polyproline with electron spins localized on attached molecular sidegroups separated by a few nanometers. We demonstrate the readout and coherent manipulation of very few (6\leq 6 ) of these S=1/2S=1/2 electronic spin systems and access their direct dipolar coupling tensor. Our results show, that it is feasible to use spin-labeled peptides as a resource for a molecular-qubit based network, while at the same time providing simple optical readout of single quantum states through NV-magnetometry. This work lays the foundation for building arbitrary quantum networks using well-established chemistry methods, which has many applications ranging from mapping distances in single molecules to quantum information processing.Comment: Author name typ
    corecore