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Intrinsic paramagnetic Meissner effect due to s-wave odd-frequency superconductivity
No full textIn 1933, Meissner and Ochsenfeld reported the expulsion of magnetic flux-the diamagnetic Meissner effect-from the interior of superconducting lead. This discovery was crucial in formulating the Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity. In exotic superconducting systems BCS theory does not strictly apply. A classical example is a superconductor-magnet hybrid system where magnetic ordering breaks time-reversal symmetry of the superconducting condensate and results in the stabilization of an odd-frequency superconducting state. It has been predicted that under appropriate conditions, odd-frequency superconductivity should manifest in the Meissner state as fluctuations in the sign of the magnetic susceptibility, meaning that the superconductivity can either repel (diamagnetic) or attract (paramagnetic) external magnetic flux. Here, we report local probe measurements of faint magnetic fields in a Au=Ho=Nb trilayer system using low-energy muons, where antiferromagnetic Ho (4.5 nm) breaks time-reversal symmetry of the proximity-induced pair correlations in Au. From depth-resolved measurements below the superconducting transition of Nb, we observe a local enhancement of the magnetic field in Au that exceeds the externally applied field, thus proving the existence of an intrinsic paramagnetic Meissner effect arising from an odd-frequency superconducting state.Peer reviewe
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Origin and regenerative potential of vertebrate mechanoreceptor-associated stem cells
No full textWidera D, Hauser S, Kaltschmidt C, Kaltschmidt B. Origin and regenerative potential of vertebrate mechanoreceptor-associated stem cells. Anatomy Research International. 2012;2012:1-9.Meissner corpuscles and Merkel cell neurite complexes are highly specialized mechanoreceptors present in the hairy and glabrous skin, as well as in different types of mucosa. Several reports suggest that after injury, such as after nerve crush, freeze injury, or dissection of the nerve, they are able to regenerate, particularly including reinnervation and repopulation of the mechanoreceptors by Schwann cells. However, little is known about mammalian cells responsible for these regenerative processes. Here we review cellular origin of this plasticity in the light of newly described adult neural crest-derived stem cell populations. We also discuss further potential multipotent stem cell populations with the ability to regenerate disrupted innervation and to functionally recover the mechanoreceptors. These capabilities are discussed as in context to cellularly reprogrammed Schwann cells and tissue resident adult mesenchymal stem cells
Gemälde über die Ober-Lausiz : Gesammelt auf einer kleinen Fußreise; Mit einem illuminirten Tittelkupfer / Von G. Benj. Meißner
No full textEnth. 6 Bl. Verzeichnis neuer Bücher im Verlag G. Benj. MeißnerVorlageform des Erscheinungsvermerks: Leipzig 1798 bei G. Benj. Meißner Im Fürstenhause. - Vorlageform des Erscheinungsvermerks vom Kolophon: Leipzig gedruckt bei Carl Tauchnitz.Frontisp
The Role of Foreign Currency Debt in Financial Crises: 1880-1913 vs. 1972-1997
No full textWhat is the role of foreign currency debt in precipitating financial crises? In this paper we compare the 1880 to 1913 period to recent experience. We examine debt crises, currency crises, banking crises and the interrelation between these varieties of crises. We pay special attention to the role of hard currency debt, currency mismatches and debt intolerance. We find fairly robust evidence that high exposure to foreign currency debt does not necessarily lead to a high chance of having a debt crisis, currency crisis, or a banking crisis. A key finding is some countries do not suffer from great financial fragility despite high exposure to original sin. In the nineteenth century, the British offshoots and Scandinavia generally avoided severe financial meltdowns while today many advanced countries have high original sin but have had few financial crises. The common denominator in both periods is that currency mismatches matter. A strong reserve position or high exports relative to hard currency liabilities helps decrease the likelihood of a debt crisis, currency crisis or a banking crisis. This strengthens the evidence for the hypothesis that foreign currency debt is dangerous when mis-managed. We discuss the robustness of these results and make some general comparisons based on this evidence from over 60 years of intense international capital market integration.
Meissner masses in the gCFL phase of QCD
No full textAbstractWe calculate the Meissner masses of gluons in neutral three-flavor color superconducting matter for finite strange quark mass. In the CFL phase the Meissner masses are slowly varying function of the strange quark mass. For large strange quark mass, in the so-called gCFL phase, the Meissner masses of gluons with colors a=1,2 become imaginary, indicating an instability
Ovarian mature cystic teratoma with florid vascular proliferation and Wagner-Meissner-like corpuscles
No full textAn ovarian mature cystic teratoma featuring florid vascular proliferation and Wagner-Meissner-like corpuscles is presented. The vascular proliferation is analogous to that seen in other tumors having a prominent neural component. The Wagner-Meissner-like corpuscles are viewed as evidence of a specialized type of differentiation of this neural component. To the best of our knowledge, they had not been previously reported in this setting
The Meissner effect in neutron stars
No full textWe present the first model aimed at understanding how the Meissner effect in a young neutron star affects its macroscopic magnetic field. In this model, field expulsion occurs on a dynamical time-scale, and is realized through two processes that occur at the onset of superconductivity: fluid motions causing the dragging of field lines, followed by magnetic reconnection. Focusing on magnetic fields weaker than the superconducting critical field, we show that complete Meissner expulsion is but one of four possible generic scenarios for the magnetic-field geometry, and can never expel magnetic flux from the centre of the star. Reconnection causes the release of up to ∼ 5 × 10 46 erg of energy at the onset of superconductivity, and is only possible for certain favourable early-phase dynamics and for pre-condensation fields 10 12 G ≲ B ≲ 5 × 10 14 G. Fields weaker or stronger than this are predicted to thread the whole star
Spiophanes longisetus Meissner 2005
No full text<i>Spiophanes</i> cf. <i>longisetus</i> Meissner, 2005 <p> <b>(Fig. 18)</b></p> <p> <i>Spiophanes longisetus</i> Meissner, 2005: 45–48, figs 26–28, table 1.</p> <p> <i>Spiophanes kroyeri</i> Grube, 1860. – Hartman and Fauchald, 1971: 105–106.</p> <p> <i>Material examined:</i> <b>Central Atlantic Ocean</b>, <b>Mid-Atlantic Ridge, East</b>, SO 237 (VEMA-Transit), stn 2-6, EBS, 12 Jan 2015, 5520 m, one af, tissue sample (ZMH-P 28149), one af, tissue sample (ZMH P-28150); stn 2-7, EBS, 20 Dec 2014, 5507 m, one af (ZMH P-28154), one af (ZMH-P28155), one af (SMF 30642, SEM 1330), one af (SMF 30643, SEM 1331), one mf (SMF 30644); stn 4-8, EBS, 26 Dec 2014, 5725 m, one af, tissue (ZMH P-28156); stn 4-9, EBS, 27 Dec 2014, 5733 m, two af (ZMH P-28157); stn 6-7, EBS, 2 Jan 2015, 5079 m, four af (SMF 30641, SEM 1342); stn 6-8, EBS, 2 Jan 2015, 5079 m, one af, tissue (ZMH-P 28160). <b>Mid-Atlantic Ridge</b>, <b>Central</b>, SO 237 (VEMA-Transit), stn 8-4, EBS, 6 Jan 2015, 5176 m, one af, tissue (SMF 30640, SEM 1327). <b>Mid-Atlantic Ridge, West</b>, SO 237 (VEMA-Transit), stn 9-8, EBS, 12 Jan 2015, 5004 m, one af, tissue (ZMH-P 28162, SEM), one af, tissue (SMF 30639), one af, tissue (ZMH P-28164); stn 11-4, EBS, 14 Jan 2015, 5108 m, one af (SMF 30638). <b>SW Atlantic Ocean</b>, Brazil Basin N, M 79-1 (DIVA 3), stn 604-1, EBS, 31 Aug 2012, 5180 m, one af, tissue (SMF 30645), one af, tissue (SMF 30646). – for details and additional specimens see the Supporting Information, Table S2.</p> <p> <i>Description:</i> (Focusing on most important characters for specimens examined in the course of the present study.) Specimens all anterior fragments with up to 23 chaetigers, between 0.2 and 0.9 mm in width, and up to 6.4 mm long. Prostomium bell-shaped with straight anterior margin extending into short anterolateral projections (Fig. 18A, B), short, stout cirriform occipital antenna with rounded tip (Fig. 18B, C). Dorsal ciliated organs as dorsal ciliated grooves posterior to the prostomium (ciliation detectable with SEM), if viewed with LM appearing as thick, straight, double lines of ochre or yellowish colour reaching the end of the 2nd chaetiger (Fig. 18A, B), sometimes outer margins of ciliated grooves demarcated and nuchal organ then appearing as pair of short U-shaped double lines. Ventral sabre chaetae from chaetiger 4, oħen of imposing length (Fig. 18C, D, G). Chaetal spreader of the ‘0 + 1 type’ with semicircular glandular opening developed in chaetigers 5–7, in chaetiger 8 chaetal spreader present but with only small hole-like opening (Fig. 18D); glandular organ of chaetigers 9–14 opens as a lateral vertical slit, without chaetal spreader. Bacillary chaetae as thin hirsute bristles can be exposed on chaetigers 5–8 though small opening of glandular organ on chaetiger 8 allowing only the protrusion of distal tips of very few bacillary chaetae (Fig. 18D). Few single ciliated patches randomly present in parapodia of the middle body region or completely absent. Ventrolateral intersegmental genital pouches absent. Posterior region starting at chaetiger 15 with first presence of neuropodial quadridentate hooks with main fang surmounted by single tooth and two uppermost smaller teeth in parallel position, hooks with half-hood from the tip of the main fang to the shaħ, usually four to five hooks, in some juveniles only three hooks arranged in one row (Fig. 18F, H, I); single, thin accompanying capillaries oħen present, observed in position next to sabre chaeta; notopodia with slightly granulated capillaries arranged in a tuħ, among those few strikingly long capillaries. Pygidium not observed in examined specimens (all anterior fragments).</p> <p> <i>Pigmentation:</i> All examined specimens pale without pigmentation, only nuchal organ with yellowish or ochre pigment as in related species (Fig. 18A). According to original description for <i>S. longisetus</i> Meissner, 2005 yellow to orange pigment in neuropodia of chaetigers 11–14 present. Remnants of faint brownish pigment in neuropodia 11–14 in few specimens discernible (e.g. SMF 30645), but usually absent.</p> <p> <i>Methyl green staining pattern:</i> Chaetigers of the anterior middle body region, and especially their subepidermal glandular organs, most intensely stained and also most persistently stained compared to other parts of the body. In chaetiger 8, lateral part of the neuropodium most intensively stained, in lateral view observed as dark circular area (Fig. 18A, E).</p> <p> <i>Biology:</i> Information about reproduction and development not available, because none of the studied specimens was bearing gametes.</p> <p> <i>Remarks:</i> The species is morphological very similar to other congeners from the deep-sea discussed in this paper: <i>S. australis</i> sp. nov. (found in the SW Atlantic and adjacent Antarctic waters) and <i>S. pacificus</i> sp. nov (collected from the Pacific Ocean). All three species are morphologically best distinguished by the distribution of lateral neuropodial ciliated patches along the middle body region, which are arranged in distinct paưerns in <i>S. australis</i> sp. nov. and <i>S. pacificus</i> sp. nov. but are only randomly found as single patches in <i>S</i>. cf. <i>longisetus</i>, or also completely absent in the laưer. The number of neuropodial hooks in posterior chaetigers is with (3)4–5 highest in <i>S</i>. cf. <i>longisetus</i> whereas in <i>S. australis</i> sp. nov. (3–)4 hooks are present and in <i>S. pacificus</i> sp. nov. usually not more than three hooks are found. The species can also be distinguished based on information from molecular markers (<i>COI</i>). However, the identity of specimens here referred to as <i>S</i>. cf. <i>longisetus</i> is not entirely resolved. The problem is mainly caused by the lack of information on molecular markers for <i>S. longisetus</i> Meissner, 2005 from type material or other specimens from the type locality. Moreover, our search in public sources (GenBank, BOLD) for sequences in good agreement with our putative species here referred to as <i>S</i>. cf. <i>longisetus</i> was unsuccessful. Based on what we know today molecular information is indispensable for solving the problem of the species identity since another <i>Spiophanes</i> species from the abyssal NE Atlantic is known: <i>S. abyssalis</i> Maciolek, 2000. Records for this species come from two different localities in the Bay of Biscay and the type locality close to the Canary Islands. <i>Spiophanes abyssalis</i> is morphologically extremely close to <i>S. longisetus</i>. Morphological differences concern the hood of the neuropodial hooks which are described as rudimentary and hard to observe in <i>S. longisetus</i> whereas they are clearly visible in <i>S. abyssalis</i> (Meissner 2005). In the laưer species, four to five hooks were observed, in <i>S. longisetus</i> three to five. <i>Spiophanes longisetus</i> can also be identified by the presence of long granulated notopodial chaetae from chaetiger 14 whereas for <i>S. abyssalis</i> posterior notopodial chaetae are described as simple narrowly sheathed capillaries [updated species description in Meissner (2005)]. Also, in the original description Maciolek (2000) describes the notochaetae as comparatively short and moreover states the presence of two eyes in the holotype. Since the here examined specimens from the central Atlantic present very long notopodial capillaries, up to five neuropodial hooks and no eyes, we here refer to them as <i>S</i>. cf. <i>longisetus</i>. However, a more reliable conclusion will be possible if additional molecular information becomes available and a subsequent review of the morphology of all involved species, especially in regard to the newly discovered ciliated patches and the number of neuropodial hooks in relation to specimen size, can be undertaken.</p> <p> <i>Distribution:</i> <i>Spiophanes longisetus</i> Meissner, 2005 has been described from localities in the NW Atlantic Ocean (Meissner 2005). Type material and additional non-type material studied while describing the species all came from slope and abyssal depths off New England and Bermuda in the NW Atlantic Ocean (Meissner 2005). Specimens studied in the course of the present study and tentatively suggested to belong to <i>S. longisetus</i> came from the VEMA fracture zone of the Mid-Atlantic Ridge and abyssal plains east and west of it, as well as from the Brazil Basin in the northern South Atlantic Ocean (Fig. 5). Water depths were 3753–4663 m in the Western North Atlantic, 5004–5733 m at locations near the Mid-Atlantic Ridge, and 5200 m in the Brazil Basin. As soon as new information on genetic markers for specimens from the type locality becomes available and the uncertainty concerning the identity of the different specimens can be dispelled, the distribution of <i>S. longisetus</i> has to be revalidated.</p>Published as part of <i>Meissner, Karin, Schwentner, Martin, Göưing, Miriam & Fiege, Thomas Knebelsberger and Dieter, 2023, Polychaetes distributed across oceans-examples of widely recorded species from abyssal depths of the Atlantic and Pacific Oceans, pp. 906-944 in Zoological Journal of the Linnean Society 199</i> on pages 936-938, DOI: 10.1093/zoolinnean/zlad069, <a href="http://zenodo.org/record/10470369">http://zenodo.org/record/10470369</a>
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Meissner holes in remagnetized superconductors
No full textFlux distributions on different faces of YBCO single crystals remagnetized by unidirectional and rotating fields are studied using advanced magneto-optical techniques. Unusual structures corresponding to the appearance of strong current concentration along certain fronts are found. At such fronts the vortex lines bend into closed loops which then collapse and form flux free cylinders. Strong magnetization currents along these Meissner holes result in essential flux redistribution and development of dynamical instabilities in the samples
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