89 research outputs found
Update Landeskunde. Ein Workshop-Format zur Fortbildung von DaF-LehrkrÀften in Tiflis
Der Artikel prĂ€sentiert ein landeskundliches Workshop-Modell fĂŒr internationale DaF-Lehrende, das im Herbst 2022 am Goethe Institut Tiflis erstmals durchgefĂŒhrt wurde. Auf der Basis vorher ermittelter kulturbezogener Bedarfe der teilnehmenden DaF-LehrkrĂ€fte zielt der Workshop darauf, thematische, methodisch-didaktische und theoretische Entwicklungen und Neuperspektivierungen auf dem Feld landeskundlichen Lernens in anwendungsorientierter Form aufzubereiten und zu vermitteln. Im Zentrum stehen dabei primĂ€r die Analyse ausgewĂ€hlter LehrwerkĂŒbungen sowie die Entwicklung sowohl thematisch als auch methodisch zeitgemĂ€Ăer kulturbezogener Lehr- und Lernmaterialien, wobei in inhaltlicher Perspektive insbesondere Aspekte der Gender-, Klima- und Migrationsdebatte fokussiert werden. Dass in den Kontexten internationaler DaF-Kulturvermittlung eminenter Bedarf nach einem Update bisheriger Landeskundedidaktik und Landeskundematerialien besteht, wurde im Rahmen des Tifliser Workshops deutlich
Young core collapse supernova remnants and their supernovae
Massive star supernovae can be divided into four categories depending on the
amount of mass loss from the progenitor star and the star's radius: red
supergiant stars with most of the H envelope intact (SN IIP), stars with some H
but most lost (IIL, IIb), stars with all H lost (Ib, Ic), and blue supergiant
stars with a massive H envelope (SN 1987A-like). Various aspects of the
immediate aftermath of the supernova are expected to develop in different ways
depending on the supernova category: mixing in the supernova, fallback on the
central compact object, expansion of any pulsar wind nebula, interaction with
circumstellar matter, and photoionization by shock breakout radiation. The
observed properties of young supernova remnants allow many of them to be placed
in one of the supernova categories; all the categories are represented except
for the SN 1987A-like type. Of the remnants with central pulsars, the pulsar
properties do not appear to be related to the supernova category. There is no
evidence that the supernova categories form a mass sequence, as would be
expected in a single star scenario for the evolution. Models for young pulsar
wind nebulae expanding into supernova ejecta indicate initial pulsar periods of
10-100 ms and approximate equipartition between particle and magnetic energies.
Ages are obtained for pulsar nebulae, including an age of 2400 pm 500 yr for
3C58, which is not consistent with an origin in SN 1181. There is no evidence
that mass fallback plays a role in neutron star properties.Comment: 43 pages, ApJ, revised, discussion of 3C58 changed, in press for Feb.
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A Spitzer Survey for Dust in Type IIn Supernovae
Recent observations suggest that Type IIn supernovae (SNe IIn) may exhibit
late-time (>100 days) infrared (IR) emission from warm dust more than other
types of core-collapse SNe. Mid-IR observations, which span the peak of the
thermal spectral energy distribution, provide useful constraints on the
properties of the dust and, ultimately, the circumstellar environment,
explosion mechanism, and progenitor system. Due to the low SN IIn rate (<10% of
all core-collapse SNe), few IR observations exist for this subclass. The
handful of isolated studies, however, show late-time IR emission from warm dust
that, in some cases, extends for five or six years post-discovery. While
previous Spitzer/IRAC surveys have searched for dust in SNe, none have targeted
the Type IIn subclass. This article presents results from a warm Spitzer/IRAC
survey of the positions of all 68 known SNe IIn within a distance of 250 Mpc
between 1999 and 2008 that have remained unobserved by Spitzer more than 100
days post-discovery. The detection of late-time emission from ten targets
(~15%) nearly doubles the database of existing mid-IR observations of SNe IIn.
Although optical spectra show evidence for new dust formation in some cases,
the data show that in most cases the likely origin of the mid-IR emission is
pre-existing dust, which is continuously heated by optical emission generated
by ongoing circumstellar interaction between the forward shock and
circumstellar medium. Furthermore, an emerging trend suggests that these SNe
decline at ~1000--2000 days post-discovery once the forward shock overruns the
dust shell. The mass-loss rates associated with these dust shells are
consistent with luminous blue variable (LBV) progenitors.Comment: Accepted for publication to ApJ, 17 pages, 10 figures, 10 table
Evaluation of the Tobacco Heating System 2.2. Part 2: Chemical composition, genotoxicity, cytotoxicity, and physical properties of the aerosol
The chemical composition, in vitro genotoxicity, and cytotoxicity of the mainstream aerosol from the
Tobacco Heating System 2.2 (THS2.2) were compared with those of the mainstream smoke from the 3R4F
reference cigarette. In contrast to the 3R4F, the tobacco plug in the THS2.2 is not burnt. The low operating
temperature of THS2.2 caused distinct shifts in the aerosol composition compared with 3R4F. This
resulted in a reduction of more than 90% for the majority of the analyzed harmful and potentially
harmful constituents (HPHCs), while the mass median aerodynamic diameter of the aerosol remained
similar. A reduction of about 90% was also observed when comparing the cytotoxicity determined by the
neutral red uptake assay and the mutagenic potency in the mouse lymphoma assay. The THS2.2 aerosol
was not mutagenic in the Ames assay. The chemical composition of the THS2.2 aerosol was also evaluated under extreme climatic and puffing conditions. When generating the THS2.2 aerosol under
âdesertâ or âtropicalâ conditions, the generation of HPHCs was not significantly modified. When using
puffing regimens that were more intense than the standard Health Canada Intense (HCI) machinesmoking conditions, the HPHC yields remained lower than when smoking the 3R4F reference cigarette
with the HCI regimen
The Promigratory Activity of the Matricellular Protein Galectin-3 Depends on the Activation of PI-3 Kinase
Expression of galectin-3 is associated with sarcoma progression, invasion and metastasis. Here we determined the role of extracellular galectin-3 on migration of sarcoma cells on laminin-111. Cell lines from methylcholanthrene-induced sarcomas from both wild type and galectin-3â/â mice were established. Despite the presence of similar levels of laminin-binding integrins on the cell surface, galectin-3â/â sarcoma cells were more adherent and less migratory than galectin-3+/+ sarcoma cells on laminin-111. When galectin-3 was transiently expressed in galectin-3â/â sarcoma cells, it inhibited cell adhesion and stimulated the migratory response to laminin in a carbohydrate-dependent manner. Extracellular galectin-3 led to the recruitment of SHP-2 phosphatase to focal adhesion plaques, followed by a decrease in the amount of phosphorylated FAK and phospho-paxillin in the lamellipodia of migrating cells. The promigratory activity of extracellular galectin-3 was inhibitable by wortmannin, implicating the activation of a PI-3 kinase dependent pathway in the galectin-3 triggered disruption of adhesion plaques, leading to sarcoma cell migration on laminin-111
Novel targets and future strategies for acute cardioprotection: Position Paper of the European Society of Cardiology Working Group on Cellular Biology of the Heart
Ischaemic heart disease and the heart failure that often results, remain the leading causes of death and disability in Europe and worldwide. As such, in order to prevent heart failure and improve clinical outcomes in patients presenting with an acute ST-segment elevation myocardial infarction and patients undergoing coronary artery bypass graft surgery, novel therapies are required to protect the heart against the detrimental effects of acute ischaemia/reperfusion injury. During the last three decades, a wide variety of ischaemic conditioning strategies and pharmacological treatments have been tested in the clinic - however, their translation from experimental to clinical studies for improving patient outcomes has been both challenging and disappointing. Therefore, in this Position Paper of the European Society of Cardiology Working Group on Cellular Biology of the Heart, we critically analyse the current state of ischaemic conditioning in both the experimental and clinical settings, provide recommendations for improving its translation into the clinical setting, and highlight novel therapeutic targets and new treatment strategies for reducing acute myocardial ischaemia/reperfusion injury
Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures
Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo
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