8 research outputs found
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
IRES-mediated translation of the carboxy-terminal domain of the horizontal cell specific connexin Cx55.5 in vivo and in vitro-3
M cistron, with two stable stem-loops or hairpins (HP), one at the 5' end and another at 3' end of luciferase gene. pRF-IR1 construct carrying the coding region (from nt631 to nt1200) of the CT in the intercistronic region, and pRF-IR2 construct with the coding region (from nt631 to nt990) of the CT in the intercistronic region. B) IRES activity of the above three constructs in N2A, HeLa and NIH3T3 cells. The IRES activity is represented as ratio of to luciferase activity (FLuc/RLuc) with the activity of the control vector, pRF-Di cis set is at 1. Each construct was tested five times and each experiment was done in triplicate. Data are expressed as mean ± SEM.<p><b>Copyright information:</b></p><p>Taken from "IRES-mediated translation of the carboxy-terminal domain of the horizontal cell specific connexin Cx55.5 in vivo and in vitro"</p><p>http://www.biomedcentral.com/1471-2199/9/52</p><p>BMC Molecular Biology 2008;9():52-52.</p><p>Published online 27 May 2008</p><p>PMCID:PMC2435236.</p><p></p
IRES-mediated translation of the carboxy-terminal domain of the horizontal cell specific connexin Cx55.5 in vivo and in vitro-7
Ts were transiently expressed in NIH3T3 cells. Confocal images were collected using the LSM510 Meta system and software. Pictures shown represent single optical planes which are presented in pseudocolours for better representation of the staining intensity. Red label indicates maximal concentration. A, B) Wild-type Cx55.5 construct (WT) co-expressing the full length Cx55.5-FLAG and p11-CT-FLAG fusion proteins. (magnification in A: 40×, Scale bar = 30 μm; in B: 63× magnification, Scale bar = 15 μm). Highest concentrations occur in perinuclear regions and the nucleus. B) Higher magnification of the WT construct with a ROI (1) showing punctuate membrane label. C) FLAG-tagged p11-CT with maximal concentration in the nuclei. The arrowheads in the inset indicates the characteristic nuclear localization of p11-CT. (magnification: 40×; Scale bar 30 μm). D) FLAG-tagged FL protein encoding for the full length Cx55.5 protein only (magnification 63×, Scale bar: 15 μm). Besides lack of nuclear staining plaque-like protein assemblies occur at sites of cell contacts (indicated by arrowheads in inset 2 and 3). Such membrane bound fluorescence was not observed with the p11-CT construct. (E) Western blot analysis of cytosolic and nuclear fractions of Cx55.5-FLAG, FL-FLAG and p11-CT-FLAG transfected N2A cells. 20 μg of total nuclear and 10 μg of cytosolic protein was separated by SDS-PAGE on a 12% gel. Immunoblot detection was done using anti-Cx55.5 as primary antibody (1 μg/ml). The upper lanes represent the full length Cx55.5 protein products expressed by the Cx55.5 wildtype protein and the FL mutant. The middle lane refers to the p11-CT protein expressed by the Cx55.5 wildtype and p11-CT proteins, but not by the FL mutation. The lower blot depicts the β-actin control. Note that the β-actin signal in the nuclear fraction is significantly reduced despite the fact that more protein was loaded on the gel. This indicates a minimal contamination with cytoplasmic remnants.<p><b>Copyright information:</b></p><p>Taken from "IRES-mediated translation of the carboxy-terminal domain of the horizontal cell specific connexin Cx55.5 in vivo and in vitro"</p><p>http://www.biomedcentral.com/1471-2199/9/52</p><p>BMC Molecular Biology 2008;9():52-52.</p><p>Published online 27 May 2008</p><p>PMCID:PMC2435236.</p><p></p
IRES-mediated translation of the carboxy-terminal domain of the horizontal cell specific connexin Cx55.5 in vivo and in vitro-4
File for further explanation). B) IRES activity and cryptic activity of the above constructs in N2A, HeLa and NIH3T3 cells. The IRES activity is represented as the ratio of to luciferase (FLuc/RLuc) with the activity of the control vector, pRF-Di cis, set at "1". Each construct was tested three times and each experiment was done in triplicate. Data are expressed as mean ± SEM<p><b>Copyright information:</b></p><p>Taken from "IRES-mediated translation of the carboxy-terminal domain of the horizontal cell specific connexin Cx55.5 in vivo and in vitro"</p><p>http://www.biomedcentral.com/1471-2199/9/52</p><p>BMC Molecular Biology 2008;9():52-52.</p><p>Published online 27 May 2008</p><p>PMCID:PMC2435236.</p><p></p
IRES-mediated translation of the carboxy-terminal domain of the horizontal cell specific connexin Cx55.5 in vivo and in vitro-6
Re (HP), the chimeric human globin intron (137 nt), and the primers used for RT-PCR analysis indicated as arrows (see Additional file ). B) RT-PCR from N2A cells transiently transfected with the control vector pRF-Di cis and the pRF-IR2 construct. A 1 kbp DNA ladder is shown on the left side of the gel. NTC, denotes no template control, PCR products generated from plasmid DNA are denoted as plasmid. RT-PCR products are indicated as cDNA. The 18s rRNA control PCR served as internal standard as described previously (49)<p><b>Copyright information:</b></p><p>Taken from "IRES-mediated translation of the carboxy-terminal domain of the horizontal cell specific connexin Cx55.5 in vivo and in vitro"</p><p>http://www.biomedcentral.com/1471-2199/9/52</p><p>BMC Molecular Biology 2008;9():52-52.</p><p>Published online 27 May 2008</p><p>PMCID:PMC2435236.</p><p></p
IRES-mediated translation of the carboxy-terminal domain of the horizontal cell specific connexin Cx55.5 in vivo and in vitro-5
CMV with the corresponding promoterless control vector, (III) shows the pRE-IR2 with IRES element IR2 (nt631 to nt990) in the inter-cistronic region, and (IV) the corresponding promoterless construct (pRE-IR2ΔCMV). B) Western blot of the expression product of the Di-cis constructs transiently transfected in N2A cells: The blots show the increased expression of the downstream EGFP cistron mediated by the IR2 element (III). C) Western blot of β-actin as loading control.<p><b>Copyright information:</b></p><p>Taken from "IRES-mediated translation of the carboxy-terminal domain of the horizontal cell specific connexin Cx55.5 in vivo and in vitro"</p><p>http://www.biomedcentral.com/1471-2199/9/52</p><p>BMC Molecular Biology 2008;9():52-52.</p><p>Published online 27 May 2008</p><p>PMCID:PMC2435236.</p><p></p
IRES-mediated translation of the carboxy-terminal domain of the horizontal cell specific connexin Cx55.5 in vivo and in vitro-8
horizontal cells of the outer retina. Scale bar: 100 μm B) The higher magnification of the region of interest (frame in A) provided evidence for small clusters of Cx55.5 immunoreactivity inside the nuclei of HCs (see arrowheads). Scale bar: 20 μm. Antibody controls, C) omitting the primary antibody and D) blocking of the primary antibody by pre-absorption with 1 μg GST-Cx55.5 fusion protein. Nuclei were stained with Sytox Orange (Invitrogen, Karlsruhe, Germany). In order to exclude the possibility that false positive fluorescent emission was recorded from out of focus planes electron microscopical immunohistochemistry of adult retina was performed. Gap junction plaques (arrow) between HCs as shown in E) resemble characteristic membrane associated structures detected with the Cx55.5 antibody, whereas the formation of small clusters (arrows) within the nucleus as shown in F) was typical for nuclear Cx55.5 immunoreactivity. The localization and number of clusters in a single section as shown in the inset was variable but did not exceed N = 3. Note that Cx55.5 immunoreactivity was never found outside the HC layer. Scale bars: 400 nm (E), 300 nm (F). (G) Western blot analysis of total protein extracts isolated from adult retina indicates a doublet of bands at the position 56 kDa and a low molecular weight band at the position 16 kDa. H) Western blot analysis of protein extracts isolated by subcellular fractionation of the adult retina (cyto = cytosolic fraction, nucl = nuclear fraction). The full length Cx55.5 protein product was enriched in the cytoplasmic fraction which is composed of soluble cytosolic proteins and membrane proteins (upper lanes). The 16 kDa protein product was found in the cytosolic and nuclear fraction (middle lanes). The lower blot depicts the β-actin control. Note the faint β-actin band in the nuclear fraction indicating minimal contamination with cytoplasmic remnants. The results shown derived from two independent western blot runs using the same samples (upper and lower lanes: 10% SDS-PAGE; middle lane; 15% SDS-PAGE).<p><b>Copyright information:</b></p><p>Taken from "IRES-mediated translation of the carboxy-terminal domain of the horizontal cell specific connexin Cx55.5 in vivo and in vitro"</p><p>http://www.biomedcentral.com/1471-2199/9/52</p><p>BMC Molecular Biology 2008;9():52-52.</p><p>Published online 27 May 2008</p><p>PMCID:PMC2435236.</p><p></p
Schematic view of wild type full length WT (I), frameshift mutated (position 1179) full length, p11-CT (II), and in-frame ATG replaced by GCG (position 1201) of full length Cx55
5 construct, FL (III). The frameshift mutation (II) leads to a premature stop codon at nucleotide position 1227. The carboxy-terminus of Cx55.5 is truncated by 90 amino acids and 15 amino acids are altered after the added "T" at nucleotide position 1179. B) Western blot of transiently transfected N2A cells: (lane I) Wild type (WT), (lane II) frameshift mutated p11-CT, and (lane III) ATG replaced by GCG of full length Cx55.5 (FL).<p><b>Copyright information:</b></p><p>Taken from "IRES-mediated translation of the carboxy-terminal domain of the horizontal cell specific connexin Cx55.5 in vivo and in vitro"</p><p>http://www.biomedcentral.com/1471-2199/9/52</p><p>BMC Molecular Biology 2008;9():52-52.</p><p>Published online 27 May 2008</p><p>PMCID:PMC2435236.</p><p></p