<i>Modiolus cimbricus</i> sp. nov. (Bivalvia: Mytilidae) endemic in the Kattegat-Skagerrak

Small usually beautifully coloured mussels from the Kattegat were to date identified as Modiolus adriaticus (Lamarck, 1819) since C.G.Johs. Petersen’s account of the shell-bearing molluscs was published in 1888. However, these mussels from Danish and Swedish waters represent a very distinct new species which also is endemic. The present paper serves to describe this new species, Modiolus cimbricus sp. nov., which belongs to the genus Modiolus Lamarck, 1799. The genus Gibbomodiola Sacco, 1898, to which Modiolus adriaticus has been moved, is here synonymized with Modiolus Lamarck, 1799

Phase-coherent transport in catalyst-free vapor phase deposited Bi2_2Se3_3 crystals

Free-standing Bi$_2$Se$_3$ single crystal flakes of variable thickness are grown using a catalyst-free vapor-solid synthesis and are subsequently transferred onto a clean Si$^{++}$/SiO$_2$ substrate where the flakes are contacted in Hall bar geometry. Low temperature magneto-resistance measurements are presented which show a linear magneto-resistance for high magnetic fields and weak anti-localization (WAL) at low fields. Despite an overall strong charge carrier tunability for thinner devices, we find that electron transport is dominated by bulk contributions for all devices. Phase coherence lengths \l_\phi as extracted from WAL measurements increase linearly with increasing electron density exceeding $1 \mu$m at 1.7 K. While \l_\phi is in qualitative agreement with electron electron interaction-induced dephasing, we find that spin flip scattering processes limit \l_\phi at low temperatures.Comment: 8 pages, 5 figure

Prednisolone as preservation additive prevents from ischemia reperfusion injury in a rat model of orthotopic lung transplantation

The lung is, more than other solid organs, susceptible for ischemia reperfusion injury after orthotopic transplantation. Corticosteroids are known to potently suppress pro-inflammatory processes when given in the post-operative setting or during rejection episodes. Whereas their use has been approved for these clinical indications, there is no study investigating its potential as a preservation additive in preventing vascular damage already in the phase of ischemia. To investigate these effects we performed orthotopic lung transplantations (LTX) in the rat. Prednisolone was either added to the perfusion solution for lung preservation or omitted and rats were followed for 48 hours after LTX. Prednisolone preconditioning significantly increased survival and diminished reperfusion edema. Hypoxia induced vasoactive cytokines such as VEGF were reduced. Markers of leukocyte invasiveness like matrix metalloprotease (MMP)-2, or common pro-inflammatory molecules like the CXCR4 receptor or the chemokine (C-C motif) ligand (CCL)-2 were downregulated by prednisolone. Neutrophil recruitment to the grafts was only increased in Perfadex treated lungs. Together with this, prednisolone treated animals displayed significantly reduced lung protein levels of neutrophil chemoattractants like CINC-1, CINC-2α/β and LIX and upregulated tissue inhibitor of matrix metalloproteinase (TIMP)-1. Interestingly, lung macrophage invasion was increased in both, Perfadex and prednisolone treated grafts, as measured by MMP-12 or RM4. Markers of anti-inflammatory macrophage transdifferentiation like MRC-1, IL-13, IL-4 and CD163, significantly correlated with prednisolone treatment. These observations lead to the conclusion that prednisolone as an additive to the perfusion solution protects from hypoxia triggered danger signals already in the phase of ischemia and thus reduces graft edema in the phase of reperfusion. Additionally, prednisolone preconditioning might also lead to macrophage polarization as a beneficial long-term effect

Artefaktreduktion bei und Validierung von akustisch evozierten Potentialen mittlerer Latenz

Es wird schon seit längerer Zeit versucht, akustisch evozierte Potentiale (AEP) zum Monitoring der Narkosetiefe zu verwenden. Wie bereits aufgeführt gibt es hierbei jedoch mehrere technische Probleme, dazu gehören die Definition eines Referenz-AEPs, eine reproduzierbare Signalableitung oder die Überlagerung des neurogenen Signals durch myogene Artefakte. Ziel dieser Arbeit war es daher, alternative Ableitungspositionen zu den üblichen frontomatoidalen Ableitungen zu finden, welche einer geringen Modifikation durch myogene Artefakte wie den Postauricularis Reflex (PAR) unterliegen. Hierfür wurde sowohl fronto-mastoidal als auch temporal zeitgleich ein AEP abgeleitet. Zudem sollte untersucht werden, ob durch eine Veränderung der Stimulationslautstärke eine Verbesserung des Signal-Rausch-Verhältnisses erreicht werden konnte. Als weiteren Punkt wurde die Stabilität des neurogenen Signales über die Jahre anhand einer kleinen Stichprobe von vier Probanden untersucht. Die hier vorliegende Arbeit konnte zeigen, dass in den temporalen Ableitungen über C3T5 und C4T6 sowie C5F7 und C6F8 alle relevanten Peaks (N0, P0, Na, Pa und Nb) des AEPs mittlerer Latenz (MLAEP) eindeutig identifiziert werden konnten, im Gegensatz zu den Ableitungen C3T3 und C4T4. Die Ableitungen A1Fpz und A2Fpz waren durch stark variable myogene Artefakte, wie den PAR modifiziert. Im Seitenvergleich zeigten die korrespondierenden Ableitungen im Vergleich zu benachbarten Ableitungspunkten fast identische Kurvenverläufe. Die Verwendung unterschiedlicher Stimulationslautstärken zeigte, dass selbst die hier verwendete geringste Stimulationslautstärke von 40 dB ausreichend war, um ein neurogenes Signal von guter Qualität zu erzeugen. Eine Erhöhung der Stimulationslautstärke bewirkte zwar eine Amplitudenzunahme des neurogenen Signals, es zeigte sich jedoch auch eine Verstärkung der signalmodifizierenden myogenen Artefakte. Durch eine Erhöhung der Stimulationslautstärke konnte somit keine Verbesserung des Signal-Rausch-Verhältnisses erreicht werden. Die erneute Vermessung von vier Probanden im zeitlichen Abstand von ca. fünf Jahren konnte zeigen, dass das neurogene Signal trotz großer interindividueller Variabilität, intraindividuell sehr stabil zu sein scheint. Anhand dieser Studienergebnisse lassen sich für die praktische Anwendung mehrere Optimierungsvorschläge ableiten. Zur Aufzeichnung eines MLAEPs sollten die Ableitungen C3T5 und C4T6 bevorzugt werden. Zudem besteht bei synchroner Ableitung die Möglichkeit ein redundantes Signal aufzuzeichnen. Eine Stimulationslautstärke von 40 dB erscheint völlig ausreichend. Zur weiteren Analyse der MLAEPs ist es auf der Grundlage der hier erhobenen Daten sinnvoll, ein Referenz-MLAEP für jede Untersuchungsperson abzuleiten, welches aufgrund der aktuellen Datenlage auch über längere Zeiträume stabil zu sein scheint und daher für folgende Analysen wiederverwendet werden kann

Strong Anisotropy in Liquid Water upon Librational Excitation using Terahertz Laser Fields

Tracking the excitation of water molecules in the homogeneous liquid is challenging due to the ultrafast dissipation of rotational excitation energy through the hydrogen-bonded network. Here we demonstrate strong transient anisotropy of liquid water through librational excitation using single-color pump-probe experiments at 12.3 THz. We deduce a third order response of chi^3 exceeding previously reported values in the optical range by three orders of magnitude. Using a theory that replaces the nonlinear response with a material response property amenable to molecular dynamics simulation, we show that the rotationally damped motion of water molecules in the librational band is resonantly driven at this frequency, which could explain the enhancement of the anisotropy in the liquid by the external Terahertz field. By addition of salt (MgSO4), the hydration water is instead dominated by the local electric field of the ions, resulting in reduction of water molecules that can be dynamically perturbed by THz pulses

Genetic diversity and connectivity within Mytilus spp. in the subarctic and Arctic

Climate changes in the Arctic are predicted to alter distributions of marine species. However, such changes are difficult to quantify because information on present species distribution and the genetic variation within species is lacking or poorly examined. Blue mussels,Mytilusspp. are ecosystem engineers in the coastal zone globally. In order to improve knowledge of distribution and genetic structure of theMytilus eduliscomplex in the Arctic, we analyzed 81 SNPs in 534Mytilusspp. individuals sampled at 13 sites to provide baseline data for distribution and genetic variation ofMytilusmussels in the European Arctic.Mytilus eduliswas the most abundant species found with a clear genetic split between populations in Greenland and the Eastern Atlantic. Surprisingly, analyses revealed the presence ofM. trossulusin high Arctic NW Greenland (77°N) andM. galloprovincialisor their hybrids in SW Greenland, Svalbard and the Pechora Sea. Furthermore, a high degree of hybridization and introgression between species was observed. Our study highlights the importance of distinguishing between congener species, which can display local adaptation and suggests that information on dispersal routes and barriers are essential for accurate predictions of regional susceptibility to range expansions or invasions of boreal species in the Arctic

Deguelin Attenuates Reperfusion Injury and Improves Outcome after Orthotopic Lung Transplantation in the Rat

The main goal of adequate organ preservation is to avoid further cellular metabolism during the phase of ischemia. However, modern preservation solutions do rarely achieve this target. In donor organs hypoxia and ischemia induce a broad spectrum of pathologic molecular mechanisms favoring primary graft dysfunction (PGD) after transplantation. Increased hypoxia-induced transcriptional activity leads to increased vascular permeability which in turn is the soil of a reperfusion edema and the enhancement of a pro-inflammatory response in the graft after reperfusion. We hypothesize that inhibition of the respiration chain in mitochondria and thus inhibition of the hypoxia induced mechanisms might reduce reperfusion edema and consecutively improve survival in vivo. In this study we demonstrate that the rotenoid Deguelin reduces the expression of hypoxia induced target genes, and especially VEGF-A, dose-dependently in hypoxic human lung derived cells. Furthermore, Deguelin significantly suppresses the mRNA expression of the HIF target genes VEGF-A, the pro-inflammatory CXCR4 and ICAM-1 in ischemic lungs vs. control lungs. After lung transplantation, the VEGF-A induced reperfusion-edema is significantly lower in Deguelin-treated animals than in controls. Deguelin-treated rats exhibit a significantly increased survival-rate after transplantation. Additionally, a downregulation of the pro-inflammatory molecules ICAM-1 and CXCR4 and an increase in the recruitment of immunomodulatory monocytes (CD163+ and CD68+) to the transplanted organ involving the IL4 pathway was observed. Therefore, we conclude that ischemic periods preceding reperfusion are mainly responsible for the increased vascular permeability via upregulation of VEGF. Together with this, the resulting endothelial dysfunction also enhances inflammation and consequently lung dysfunction. Deguelin significantly decreases a VEGF-A induced reperfusion edema, induces the recruitment of immunomodulatory monocytes and thus improves organ function and survival after lung transplantation by interfering with hypoxia induced signaling

A sad tale: has the small mussel Idas argenteus lost its symbionts?

Idas argenteus (Bivalvia: Mytilidae) belongs to a genus of mussels that are often associated with sunken wood and vertebrate bones in the deep sea. By contrast to other species currently included within the genus Idas and other related genera, such as Bathymodiolus, I. argenteus was documented to lack chemosynthetic symbionts bacterial symbionts in its gills. In the present study, new specimens are assigned to I. argenteus based on shell and soft parts analysis. Molecular data confirm the absence or low abundance of symbionts. Phylogeny based on five genes indicates that the symbiont-bearing I. washingtonius is the closest relative of I. argenteus. Symbiosis loss or extreme reduction is thus inferred to have occurred subsequent to the speciation event, 11–13 Mya. This is the first report of a loss of symbiosis within the clade of deep-sea chemosynthetic mussels