168 research outputs found

    The behaviour of political parties and MPs in the parliaments of the Weimar Republic

    Get PDF
    Copyright @ 2012 The Authors. This is the author's accepted manuscript. The final published article is available from the link below.Analysing the roll-call votes of the MPs of the Weimar Republic we find: (1) that party competition in the Weimar parliaments can be structured along two dimensions: an economic left–right and a pro-/anti-democratic. Remarkably, this is stable throughout the entire lifespan of the Republic and not just in the later years and despite the varying content of votes across the lifespan of the Republic, and (2) that nearly all parties were troubled by intra-party divisions, though, in particular, the national socialists and communists became homogeneous in the final years of the Republic.Zukunftskolleg, University of Konstan

    An ultrahot Neptune in the Neptune desert

    Get PDF
    About 1 out of 200 Sun-like stars has a planet with an orbital period shorter than one day: an ultrashort-period planet. All of the previously known ultrashort-period planets are either hot Jupiters, with sizes above 10 Earth radii (R⊕), or apparently rocky planets smaller than 2 R⊕. Such lack of planets of intermediate size (the ‘hot Neptune desert’) has been interpreted as the inability of low-mass planets to retain any hydrogen/helium (H/He) envelope in the face of strong stellar irradiation. Here we report the discovery of an ultrashort-period planet with a radius of 4.6 R⊕ and a mass of 29 M⊕, firmly in the hot Neptune desert. Data from the Transiting Exoplanet Survey Satellite revealed transits of the bright Sun-like star LTT 9779 every 0.79 days. The planet’s mean density is similar to that of Neptune, and according to thermal evolution models, it has a H/He-rich envelope constituting 9.0^(+2.7)_(−2.9)% of the total mass. With an equilibrium temperature around 2,000 K, it is unclear how this ‘ultrahot Neptune’ managed to retain such an envelope. Follow-up observations of the planet’s atmosphere to better understand its origin and physical nature will be facilitated by the star’s brightness (V_(mag) = 9.8)

    NGTS-4b: A sub-Neptune transiting in the desert

    Get PDF
    We report the discovery of NGTS-4b, a sub-Neptune-sized planet transiting a 13th magnitude K-dwarf in a 1.34d orbit. NGTS-4b has a mass M=20.6±3.020.6\pm3.0M_E and radius R=3.18±0.263.18\pm0.26R_E, which places it well within the so-called "Neptunian Desert". The mean density of the planet (3.45±0.953.45\pm0.95g/cm^3) is consistent with a composition of 100% H2_2O or a rocky core with a volatile envelope. NGTS-4b is likely to suffer significant mass loss due to relatively strong EUV/X-ray irradiation. Its survival in the Neptunian desert may be due to an unusually high core mass, or it may have avoided the most intense X-ray irradiation by migrating after the initial activity of its host star had subsided. With a transit depth of 0.13±0.020.13\pm0.02%, NGTS-4b represents the shallowest transiting system ever discovered from the ground, and is the smallest planet discovered in a wide-field ground-based photometric survey

    Supported lipid bilayer formation: beyond vesicle fusion

    No full text
    Supported lipid bilayers (SLBs) are cell-membrane-mimicking platforms that can be formed on solid surfaces and integrated with a wide range of surface-sensitive measurement techniques. SLBs are useful for unravelling details of fundamental membrane biology and biophysics as well as for various medical, biotechnology, and environmental science applications. Thus, there is high interest in developing simple and robust methods to fabricate SLBs. Currently, vesicle fusion is a popular method to form SLBs and involves the adsorption and spontaneous rupture of lipid vesicles on a solid surface. However, successful vesicle fusion depends on high-quality vesicle preparation, and it typically works with a narrow range of material supports and lipid compositions. In this Feature Article, we summarize current progress in developing two new SLB fabrication techniques termed the solvent-assisted lipid bilayer (SALB) and bicelle methods, which have compelling advantages such as simple sample preparation and compatibility with a wide range of material supports and lipid compositions. The molecular self-assembly principles underpinning the two strategies and important experimental parameters are critically discussed, and recent application examples are presented. Looking forward, we envision that these emerging SLB fabrication strategies can be widely adopted by specialists and nonspecialists alike, paving the way to enriching our understanding of lipid membrane properties and realizing new application possibilities.National Research Foundation (NRF)This work was supported by the National Research Foundation of Singapore through a Proof-of-Concept grant (NRF2015NRF-POC0001-19)

    Biotechnology applications of tethered lipid bilayer membranes

    No full text
    The importance of cell membranes in biological systems has prompted the development of model membrane platforms that recapitulate fundamental aspects of membrane biology, especially the lipid bilayer environment. Tethered lipid bilayers represent one of the most promising classes of model membranes and are based on the immobilization of a planar lipid bilayer on a solid support that enables characterization by a wide range of surface-sensitive analytical techniques. Moreover, as the result of molecular engineering inspired by biology, tethered bilayers are increasingly able to mimic fundamental properties of natural cell membranes, including fluidity, electrical sealing and hosting transmembrane proteins. At the same time, new methods have been employed to improve the durability of tethered bilayers, with shelf-lives now reaching the order of weeks and months. Taken together, the capabilities of tethered lipid bilayers have opened the door to biotechnology applications in healthcare, environmental monitoring and energy storage. In this review, several examples of such applications are presented. Beyond the particulars of each example, the focus of this review is on the emerging design and characterization strategies that made these applications possible. By drawing connections between these strategies and promising research results, future opportunities for tethered lipid bilayers within the biotechnology field are discussed.Published versio

    Targeting the Achilles Heel of Mosquito-Borne Viruses for Antiviral Therapy

    No full text
    Mosquito-borne viruses encompass a wide range of pathogens, such as dengue and Zika viruses, that often cocirculate geographically. These viruses affect hundreds of millions of people worldwide, yet no clinically approved therapy is currently available for treating these viral infections. Thus, innovative therapies, especially inhibitors with broad antiviral activities against all these viruses, are urgently needed. While traditional therapeutic strategies mainly focus on inhibiting viral replication in a "one lock, one key" manner (e.g., viral protease and polymerase inhibitors), inhibitors targeting virions have recently emerged as a promising approach to achieve broad antiviral activities. Within this approach, Lipid Envelope Antiviral Disruption (LEAD) molecules were shown to broadly inhibit mosquito-borne viruses and other lipid membrane-enveloped viruses. Several LEAD molecules have been demonstrated to act against viral membranes in vitro, some of which have even shown in vivo efficacy to treat mosquito-borne viral infections. This therapeutic potential is further enhanced by molecular engineering to improve the inhibitors' pharmacological properties, laying the foundation for the LEAD antiviral strategy to be explored for possible treatment of mosquito-borne viral infections.National Research Foundation (NRF)This publication was supported in part by the National Research Foundation of Singapore through a Proof-of-Concept grant (NRF2015NRF-POC0001-19) to N.-J.C. Additional support was provided by the Creative Materials Discovery Program through the National Research Foundation of Korea funded by the Ministry of Science, ICT and Future Planning (NRF-2016M3D1A1024098). P.-Y.S. lab was supported by a Kleberg Foundation Award, UTMB CTSA UL1TR-001439, Pan American Health Organization grant SCON2016-01353, and NIH grants AI127744 and AI136126

    Surface-based nanoplasmonic sensors for biointerfacial science applications

    No full text
    The design and application of surface-based nanoplasmonic sensors has spurred broad interest from the chemical science community, touching upon diverse topics such as plasmonics, nanoscience, surface chemistry, measurement analysis, and interfacial science. One of the most exciting areas involves taking advantage of the simple instrumental requirements and high surface sensitivity of these sensing devices to study biomacromolecules and biological nanoparticles. In this Account, we present a narrative summary describing our recent work to explore surface-based nanoplasmonic sensors for biointerfacial science applications and outlining our perspective on possible future directions. After introducing the basic design concepts and measurement principles behind surface-based nanoplasmonic sensors, we focus on critically discussing recent application examples from our laboratory, where the high surface sensitivity of surface-based nanoplasmonic sensors proved useful for studying lipid vesicles, supported lipid bilayers, virus-like particles, proteins, and peptides. The potential of integrating surface-based nanoplasmonic sensors with other surface-sensitive measurement techniques is also discussed. Looking forward, there is excellent potential to continue using surface-based nanoplasmonic sensors for biointerfacial science applications and numerous innovation opportunities exist from fundamental and applied perspectives.NRF (Natl Research Foundation, S’pore)Published versio
    corecore