408 research outputs found
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Marine nanogels as a source of atmospheric nanoparticles in the high Arctic
The high Arctic (north of 80°N) in summer is a region characterized by clean air and low abundances of preexisting particles. Marine colloidal nanogels i.e., assembled dissolved organic carbohydrate polymer networks have recently been confirmed to be present in both airborne particles and cloud water over the Arctic pack ice area. A novel route to atmospheric nanoparticles that appears to be operative in the high Arctic is suggested. It involves the injection of marine granular nanogels into the air from evaporating fog and cloud droplets, and is supported by observational and theoretical evidence obtained from a case study. Statistical analysis of the aerosol size distribution data recorded in the years 1991, 1996, 2001, and 2008 classified 75 nanoparticle events - covering 17% of the observed time period - as nanogel-type events, characterized by the spontaneous appearance of several distinct size bands below 200 nm diameter
" Candidatus Mesochlamydia elodeaeâ (Chlamydiae: Parachlamydiaceae ), a novel chlamydia parasite of free-living amoebae
Vannella sp. isolated from waterweed Elodea sp. was found infected by a chlamydia-like organism. This organism behaves like a parasite, causing the death through burst of its host. Once the vannellae degenerated, the parasite was successfully kept in laboratory within a Saccamoeba sp. isolated from the same waterweed sample, which revealed in fine through electron microscopy to harbor two bacterial endosymbionts: the chlamydial parasite we introduce and another endosymbiont initially and naturally present in the host. Herein, we provide molecular-based identification of both the amoeba host and its two endosymbionts, with special focus on the chlamydia parasite. High sequence similarity values of the 18S rDNA permitted to assign the amoeba to the species Saccamoeba lacustris (Amoebozoa, Tubulinea). The bacterial endosymbiont naturally harbored by the host belonged to Sphingomonas koreensis (Alpha-Proteobacteria). The chlamydial parasite showed a strict specificity for Saccamoeba spp., being unable to infect a variety of other amoebae, including Acanthamoeba, and it was itself infected by a bacteriophage. Sequence similarity values of the 16S rDNA and phylogenetic analysis indicated that this strain is a new member of the family Parachlamydiaceae, for which we propose the name "Candidatus Mesochlamydia elodeae.
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New insights in sources of the sub-micrometre aerosol at Mt. Zeppelin observatory (Spitsbergen) in the year 2015
In order to evaluate the potential impact of the Arctic anthropogenic emission sources it is essential to understand better the natural aerosol sources of the inner Arctic and the atmospheric processing of the aerosols during their transport in the Arctic atmosphere. A 1-year time series of chemically specific measurements of the sub-micrometre aerosol during 2015 has been taken at the Mt. Zeppelin observatory in the European Arctic. A source apportionment study combined measured molecular tracers as source markers, positive matrix factorization, analysis of the potential source distribution and auxiliary information from satellite data and ground-based observations. The annual average sub-micrometre mass was apportioned to regional background secondary sulphate (56%), sea spray (17%), biomass burning (15%), secondary nitrate (5.8%), secondary marine biogenic (4.5%), mixed combustion (1.6%), and two types of marine gel sources (together 0.7%). Secondary nitrate aerosol mainly contributed towards the end of summer and during autumn. During spring and summer, the secondary marine biogenic factor reached a contribution of up to 50% in some samples. The most likely origin of the mixed combustion source is due to oil and gas extraction activities in Eastern Siberia. The two marine polymer gel sources predominantly occurred in autumn and winter. The small contribution of the marine gel sources at Mt. Zeppelin observatory in summer as opposed to regions closer to the North Pole is attributed to differences in ocean biology, vertical distribution of phytoplankton, and the earlier start of the summer season
The Code of Protest. Images of Peace in the West German Peace Movements, 1945-1990
The article examines posters produced by the peace movements in the Federal Republic of
Germany during the ColdWar, with an analytical focus on the transformation of the iconography
of peace in modernity. Was it possible to develop an independent, positive depiction of peace
in the context of protests for peace and disarmament? Despite its name, the pictorial selfrepresentation
of the campaign âFight against Nuclear Deathâ in the late 1950s did not draw
on the theme of pending nuclear mass death. The large-scale protest movement in the 1980s
against NATOâs 1979 âdouble-trackâ decision contrasted female peacefulness with masculine
aggression in an emotionally charged pictorial symbolism. At the same time this symbolism
marked a break with the pacifist iconographic tradition that had focused on the victims of war.
Instead, the movement presented itself with images of demonstrating crowds, as an anticipation
of its peaceful ends. Drawing on the concept of asymmetrical communicative âcodesâ that has
been developed in sociological systems theory, the article argues that the iconography of peace in
peace movement posters could not develop a genuinely positive vision of peace, since the code of
protest can articulate the designation value âpeaceâ only in conjunction with the rejection value
âwarâ
Abschlussbericht der Bund-LĂ€nder-Kommission Rechtsterrorismus vom 30. April 2013
Das Bekanntwerden des âNationalsozialistischen Untergrundesâ (NSU) im November 2011 und die dieser Gruppierung zugeschriebenen zahlreichen bis dahin ungeklĂ€rten Verbrechen haben die Ăffentlichkeit in Deutschland erschĂŒttert. Dies lag vor allem daran, dass es drei Jenaer Rechtsterroristen gelingen konnte, ĂŒber einen Zeitraum von fast vierzehn Jahren von den Sicherheitsbehörden in Bund und LĂ€ndern unentdeckt in Deutschland schwerste Straftaten zu begehen. Dadurch wurde das Vertrauen der Bevölkerung in die Arbeit von Polizei und Verfassungsschutz nachhaltig beeintrĂ€chtigt.
Als Entstehungszeitpunkt des NSU kann der 26. Januar 1998 angesehen werden. Aus Anlass einer Durchsuchung an diesem Tag tauchten Uwe Böhnhardt, Uwe Mundlos und Beate ZschĂ€pe unter und waren bis zu ihrem Tod bzw. ihrer Festnahme auf der Flucht. Böhnhardt, Mundlos und ZschĂ€pe waren Mitglieder des âThĂŒringer Heimatschutzesâ (THS) und den Behörden insoweit bereits seit 1995 als Rechtsextremisten bekannt. Sie hatten seit dieser Zeit an mehreren Demonstrationen und rechtsextremistischen Musikveranstaltungen teilgenommen. Alle drei waren polizeilich in Erscheinung getreten; Uwe Böhnhardt und Uwe Mundlos waren wegen rechtsextremistischer Straftaten verurteilt worden. ZschĂ€pe hatte Straftaten aus dem Bereich der allgemei-nen KriminalitĂ€t begangen. Nach dem Untertauchen im Januar 1998 hielt sich das Trio in Sachsen auf und wurde durch etliche Helfer aus der rechtsextremistischen Szene in ThĂŒringen und Sachsen unterstĂŒtzt. SpĂ€testens 1999 begannen mutmaĂlich Böhnhardt und Mundlos damit, RaubĂŒberfĂ€lle zu begehen. Im Jahr 2000 begann eine Serie von rechtsterroristischen Morden und SprengstoffanschlĂ€gen, die zumindest Mundlos und Böhnhardt und der Anklageschrift des Generalbundesanwalts vom 5. November 2012 zufolge auch ZschĂ€pe zugerechnet werden muss. Im Verlauf dieser Verbrechens-serie wurden in sechs BundeslĂ€ndern insgesamt zehn Menschen getötet und mehr als 20 teilweise schwer verletzt. Bei den Todesopfern handelt es sich um: Enver ĆimĆek, NĂŒrnberg (9. September 2000), Abdurrahim ĂzĂŒdoÄru, NĂŒrnberg (13. Juni 2001), SĂŒleyman TaĆköprĂŒ, Hamburg (27. Juni 2001), Habil Kılıç, MĂŒnchen (29. August 2001), Mehmet Turgut, Rostock (25. Februar 2004), Ä°smail YaĆar, NĂŒrnberg (5. Juni 2005), Theodoros Boulgarides, MĂŒnchen (15. Juni 2005), Mehmet KubaĆık, Dortmund (4. April 2006), Halit Yozgat, Kassel (6. April 2006), MichĂšle Kiesewetter, Heilbronn (25. April 2007). Der letzte durch Böhnhardt und Mundlos am 4. November 2011 verĂŒbte RaubĂŒberfall stellt den Endpunkt des Wirkens des NSU dar. Als beide von der Polizei auf ihrer Flucht entdeckt wurden, töteten sie sich. Im Rahmen der sich anschlieĂenden Ermittlungen wurde von den Sicherheitsbehörden der Gesamtzusammenhang der von dem Trio begangenen Taten erkannt. Vor dem Hintergrund dieser erschĂŒtternden Verbrechensserie hat die gemeinsam durch die StĂ€ndige Konferenz der Innenminister und - senatoren der LĂ€nder und die Bundesregierung eingesetzte Bund-LĂ€nder-Kommission Rechtsterrorismus in diesem Abschlussbericht die Sicherheitsarchitektur in Deutschland und die Zusammenarbeit zwischen den verschiedenen Behörden eingehend analysiert, Schwachstellen gezeigt und Verbesserungsempfehlungen entwickelt
High-Sensitivity Cardiac Troponin T in Patients with Severe Chronic Kidney Disease and Suspected Acute Coronary Syndrome
(1) Background: Patients with severe chronic kidney disease (CKD G4âG5) often have chronically elevated high-sensitivity cardiac troponin T (hs-cTnT) values above the 99th percentile of the upper reference limit. In these patients, optimal cutoff levels for diagnosing non-ST-elevation acute coronary syndrome (NSTE-ACS) requiring revascularization remain undefined. (2) Methods: Of 11,912 patients undergoing coronary angiography from 2012 to 2017 for suspected NSTE-ACS, 325 (3%) had severe CKD. Of these, 290 with available serial hs-cTnT measurements were included, and 300 matched patients with normal renal function were selected as a control cohort. (3) Results: In the CKD cohort, 222 patients (76%) had NSTE-ACS with indication for coronary revascularization. Diagnostic performance was high at presentation and similar to that of the control population (AUC, 95% CI: 0.81, 0.75â0.87 versus 0.85, 0.80â0.89, p = 0.68), and the ROC-derived cutoff value was 4 times higher compared to the conventional 99th percentile. Combining the ROC-derived cutoff levels for hs-cTnT at presentation and absolute 3 h changes, sensitivity increased to 98%, and PPV and NPV improved up to 93% and 86%, respectively. (4) Conclusions: In patients with severe CKD and suspected ACS, the diagnostic accuracy of hs-cTnT for the diagnosis of NSTE-ACS requiring revascularization is improved by using higher assay-specific cutoff levels combined with early absolute changes
idMesh: graph-based disambiguation of linked data
We tackle the problem of disambiguating entities on the Web. We propose a user-driven scheme where graphs of entities -- represented by globally identifiable declarative artifacts -- self-organize in a dynamic and probabilistic manner. Our solution has the following two desirable properties: i) it lets end-users freely define associations between arbitrary entities and ii) it probabilistically infers entity relationships based on uncertain links using constraint-satisfaction mechanisms. We outline the interface between our scheme and the current data Web, and show how higher-layer applications can take advantage of our approach to enhance search and update of information relating to online entities. We describe a decentralized infrastructure supporting efficient and scalable entity disambiguation and demonstrate the practicability of our approach in a deployment over several hundreds of machines
Ambient Observations of Sub-1.0 Hygroscopic Growth Factor and F(RH) Values: Case Studies from Surface and Airborne Measurements
This study reports on the first set of ambient observations of sub-1.0 hygroscopicity values (i.e., growth factor, ratio of humidified-to-dry diameter, GF=Dp,wet/Dp,dry and f(RH), ratio of humidified-to-dry scattering coefficients, less than 1) with consistency across different instruments, regions, and platforms. We utilized data from a shipboard humidified tandem differential mobility analyzer (HTDMA) during Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE) in 2011, multiple instruments on the DC-8 aircraft during Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) in 2013, as well as the Differential Aerosol Sizing and Hygroscopicity Spectrometer Probe (DASH-SP) during measurement intensives during Summer 2014 and Winter 2015 in Tucson, Arizona. Sub-1.0 GFs were observed across the range of relative humidity (RH) investigated (75-95%), and did not show a RH-dependent trend in value below 1.0 or frequency of occurrence. A commonality between suppressed hygroscopicity in these experiments, including sub-1.0 GF, was the presence of smoke. Evidence of externally mixed aerosol, and thus multiple GFs, was observed during smoke periods resulting in at least one mode with GF < 1. Time periods during which the DASH-SP detected externally mixed aerosol coincide with sub-1.0 f(RH) observations. Mechanisms responsible for sub-1.0 hygroscopicity are discussed and include refractive index (RI) modifications due to aqueous processing, particle restructuring, and volatilization effects. To further investigate ambient observations of sub-1.0 GFs, f(RH), and particle restructuring, modifying hygroscopicity instruments with pre-humidification modules is recommended
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