EUV Emission and Scattered Light Diagnostics of Equatorial Coronal Holes as Seen by Hinode/EIS

Spectroscopic diagnostics of solar coronal plasmas critically depends on the uncertainty in the measured line intensities. One of the main sources of uncertainty is instrumental scattered light, which is potentially most important in low-brightness areas. In the solar corona, such areas include polar and equatorial coronal holes, which are the source regions of the solar wind; instrument-scattered light must thus pose a significant obstacle to studies of the source regions of the solar wind. In this paper we investigate the importance of instrument-scattered light on observations of equatorial coronal holes made by the Hinode/EIS spectrometer in two different phases of the solar cycle. We find that the instrument-scattered light is significant at all temperatures, and in both regions it amounts to approximately 10% of the average intensity of the neighboring quiet Sun regions. Such contribution dominates the measured intensity for spectral lines formed at temperatures larger than Log T = 6.15 K, and has deep implications for spectroscopic diagnostics of equatorial coronal hole plasmas and studies of the source regions of a large portion of the solar wind which reaches Earth. Our results suggest that the high temperature tail of in the coronal hole plasma distribution with temperature, however small, is an artifact due to the presence of scattered light.Comment: 11 pages, 6 figure

Rezension: Als ob sie träumend gingen: von Anna Baar

Anna Baar hat mit „Als ob sie träumend gingen“ einen beeindruckenden Roman über Erinnerung und Medialität vorgelegt. Veronika Zoidl hat sich für die MEDIENIMPULSE auf Spurensuche durch diesen Jahrhundertext gemacht.Anna Baar has presented an impressive novel on memory and mediality with „Als ob sie träumend gingen“. Veronika Zoidl has been looking for traces of this brilliant text for MEDIENIMPULSE

Characterization of the internal IRES element of the zebrafish connexin55.5 reveals functional implication of the polypyrimidine tract binding protein

<p>Abstract</p> <p>Background</p> <p>Connexin55.5 (Cx55.5) is a gap junction protein with horizontal cell-restricted expression in zebrafish accumulating at dendritic sites within the receptor-horizontal cell complex in form of hemichannels where light-dependent plasticity occurs. This connexin is the first example of a gap junction protein processed to form two protein isoforms from a monocistronic message by an IRES mediated process. The nuclear occurrence of a carboxy-terminal fragment of this protein provides evidence that this gap junction protein may participate in a putative cytoplasmic to nuclear signal transfer.</p> <p>Results</p> <p>We characterized the IRES element of Cx55.5 in terms of sequence elements necessary for its activity and protein factor(s), which may play a role for its function. Two stretches of polypyrimidine tracts designated PPT1 and PPT2 which influence the IRES activity of this neuronal gap junction protein were identified. Selective deletion of PPT1 results in an appreciable decrease of the IRES activity, while the deletion of PPT2 results in a complete loss. RNA-EMSA and UV-cross linking experiments showed that protein complexes bind to this IRES element, of which the polypyrimidine tract binding protein (PTB) was identified as one of the interacting partners with influence on IRES activity. These results indicate that PTB conveys a role in the regulation of the IRES activity of Cx55.5.</p> <p>Conclusion</p> <p>Our findings indicate that the activity of the IRES element of the neuronal gap junction protein Cx55.5 is subject of regulation through flanking polypyrimidine tracts, and that the non-canonical trans-activation factor PTB plays an essential role in this process. This observation is of considerable importance and may provide initial insight into molecular-functional relationships of electrical coupling in horizontal cells.</p

Rezension: Insekten von Regina Hofer und Leopold Maurer.

Veronika Zoidl präsentiert mit dieser Rezension die jüngste Publikation von Regina Hofer und Leopold Maurer. Die von der Autorin und dem Autor gestaltete Graphic Novel führt uns in die düstersten Vergangenheiten unserer Geschichte, wenn der nationalsozialistische Großvater Maurers zum Interview gebeten wird …With this review, Veronika Zoidl presents the latest publication by Regina Hofer and Leopold Maurer. The graphic novel, designed by the authors, takes us into the darkest past of our history when Maurers grandfather defends National Socialism in a series of interviews ..

The absent father in modern American drama

Die vorliegende Arbeit beschäftigt sich mit der Analyse von sechs modernen amerikanischen Stücken, die die Zeitspanne von 1945 bis 2002 umfassen. Sämtliche Stücke haben gemeinsam, dass der Vater als das zentrale Familienoberhaupt abwesend ist und dieses Fehlen der Vaterfigur im Leben die Kinder auf oft ähnliche Weise beeinflusst.This thesis contains an analysis of six modern American plays that have an absent father at the centre of the story. It investigates how the abandoned children deal with their father's absence

Rezension: „Das flüssige Land“ von Raphaela Edelbauer.

Raphaela Edelbauer schickt ihre Protagonistin auf eine Reise in ein Paralleluniversum namens Groß-Einland. Dort ticken nicht nur die Uhren anders ... &nbsp;Raphaela Edelbauer sends her protagonist on a journey to a parallel universe named Groß-Einland. There the time is out of joint ..

Elevated intracellular chloride level in albino visual cortex neurons is mediated by Na-K-Cl co-transporter

<p>Abstract</p> <p>Background</p> <p>During development the switch from a depolarizing to a hyperpolarizing action of GABA is a consequence of a decrease of the Na⁺-K⁺-2Cl^-co-transporter (NKCC1, Cl^--uptake) and increase of the K⁺-Cl^-co-transporter (KCC2, Cl^--extrusion) expression. However albino visual cortex neurons don't show a corresponding decrease in intracellular chloride concentration during development of the visual system as compared to pigmented animals.</p> <p>Results</p> <p>Our study revealed that more cells express NKCC1 in albinos compared to pigmented rat visual cortex neurons whereas KCC2 is expressed in all cells in both strains. We determined a positive relationship between the presence of NKCC1 and an inhibitory deficit in single neurons of the albino visual cortex. After pharmacological blockade of NKCC1 function with its specific inhibitor, bumetanide, the reversal potential of electrically evoked GABAA receptor-mediated postsynaptic currents and, as a consequence, [Cl-]_iin albino visual cortex neurons shifted to the pigmented rat brain value. In conclusion, our pharmacological experiments and subsequent single cell real time PCR analysis of the co-transporter mRNA demonstrated that the inhibitory deficit present in the albino visual cortical network is almost exclusively mediated by NKCC1.</p> <p>Conclusion</p> <p>Our findings suggest that blocking of NKCC1 in albino visual cortex neurons could improve processing in visual cortex and therefore might be beneficial for vision in albinos.</p