20 research outputs found

    The airglow layer emission altitude cannot be determined unambiguously from temperature comparison with lidars

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    I investigate the nightly mean emission height and width of the OH*(3-1) layer by comparing nightly mean temperatures measured by the ground-based spectrometer GRIPS 9 and the Na lidar at ALOMAR. The data set contains 42 coincident measurements between November 2010 and February 2014, when GRIPS 9 was in operation at the ALOMAR observatory (69.3∘^\circN, 16.0∘^\circE) in northern Norway. To closely resemble the mean temperature measured by GRIPS 9, I weight each nightly mean temperature profile measured by the lidar using Gaussian distributions with 40 different centre altitudes and 40 different full widths at half maximum. In principle, one can thus determine the altitude and width of an airglow layer by finding the minimum temperature difference between the two instruments. On most nights, several combinations of centre altitude and width yield a temperature difference of ±\pm2 K. The generally assumed altitude of 87 km and width of 8 km is never an unambiguous, good solution for any of the measurements. Even for a fixed width of ∼\sim8.4 km, one can sometimes find several centre altitudes that yield equally good temperature agreement. Weighted temperatures measured by lidar are not suitable to determine unambiguously the emission height and width of an airglow layer. However, when actual altitude and width data are lacking, a comparison with lidars can provide an estimate of how representative a measured rotational temperature is of an assumed altitude and width. I found the rotational temperature to represent the temperature at the commonly assumed altitude of 87.4 km and width of 8.4 km to within ±\pm16 K, on average. This is not a measurement uncertainty.Comment: Version published in Atmos. Chem. Phys., 14 May 201

    Interplay between estrogen receptor and AKT in estradiol-induced alternative splicing.

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    BACKGROUND: Alternative splicing is critical for generating complex proteomes in response to extracellular signals. Nuclear receptors including estrogen receptor alpha (ERα) and their ligands promote alternative splicing. The endogenous targets of ERα:estradiol (E2)-mediated alternative splicing and the influence of extracellular kinases that phosphorylate ERα on E2-induced splicing are unknown. METHODS: MCF-7 and its anti-estrogen derivatives were used for the majority of the assays. CD44 mini gene was used to measure the effect of E2 and AKT on alternative splicing. ExonHit array analysis was performed to identify E2 and AKT-regulated endogenous alternatively spliced apoptosis-related genes. Quantitative reverse transcription polymerase chain reaction was performed to verify alternative splicing. ERα binding to alternatively spliced genes was verified by chromatin immunoprecipitation assay. Bromodeoxyuridine incorporation-ELISA and Annexin V labeling assays were done to measure cell proliferation and apoptosis, respectively. RESULTS: We identified the targets of E2-induced alternative splicing and deconstructed some of the mechanisms surrounding E2-induced splicing by combining splice array with ERα cistrome and gene expression array. E2-induced alternatively spliced genes fall into at least two subgroups: coupled to E2-regulated transcription and ERα binding to the gene without an effect on rate of transcription. Further, AKT, which phosphorylates both ERα and splicing factors, influenced ERα:E2 dependent splicing in a gene-specific manner. Genes that are alternatively spliced include FAS/CD95, FGFR2, and AXIN-1. E2 increased the expression of FGFR2 C1 isoform but reduced C3 isoform at mRNA level. E2-induced alternative splicing of FAS and FGFR2 in MCF-7 cells correlated with resistance to FAS activation-induced apoptosis and response to keratinocyte growth factor (KGF), respectively. Resistance of MCF-7 breast cancer cells to the anti-estrogen tamoxifen was associated with ERα-dependent overexpression of FGFR2, whereas resistance to fulvestrant was associated with ERα-dependent isoform switching, which correlated with altered response to KGF. CONCLUSION: E2 may partly alter cellular proteome through alternative splicing uncoupled to its effects on transcription initiation and aberration in E2-induced alternative splicing events may influence response to anti-estrogens.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Evaluation of National Surgical Practice for Lateral Lymph Nodes in Rectal Cancer in an Untrained Setting

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    Background: Involved lateral lymph nodes (LLNs) have been associated with increased local recurrence (LR) and ipsi-lateral LR (LLR) rates. However, consensus regarding the indication and type of surgical treatment for suspicious LLNs is lacking. This study evaluated the surgical treatment of LLNs in an untrained setting at a national level. Methods: Patients who underwent additional LLN surgery were selected from a national cross-sectional cohort study regarding patients undergoing rectal cancer surgery in 69 Dutch hospitals in 2016. LLN surgery consisted of either ‘node-picking’ (the removal of an individual LLN) or ‘partial regional node dissection’ (PRND; an incomplete resection of the LLN area). For all patients with primarily enlarged (≥7 mm) LLNs, those undergoing rectal surgery with an additional LLN procedure were compared to those undergoing only rectal resection. Results: Out of 3057 patients, 64 underwent additional LLN surgery, with 4-year LR and LLR rates of 26% and 15%, respectively. Forty-eight patients (75%) had enlarged LLNs, with corresponding recurrence rates of 26% and 19%, respectively. Node-picking (n = 40) resulted in a 20% 4-year LLR, and a 14% LLR after PRND (n = 8; p = 0.677). Multivariable analysis of 158 patients with enlarged LLNs undergoing additional LLN surgery (n = 48) or rectal resection alone (n = 110) showed no significant association of LLN surgery with 4-year LR or LLR, but suggested higher recurrence risks after LLN surgery (LR: hazard ratio [HR] 1.5, 95% confidence interval [CI] 0.7–3.2, p = 0.264; LLR: HR 1.9, 95% CI 0.2–2.5, p = 0.874). Conclusion: Evaluation of Dutch practice in 2016 revealed that approximately one-third of patients with primarily enlarged LLNs underwent surgical treatment, mostly consisting of node-picking. Recurrence rates were not significantly affected by LLN surgery, but did suggest worse outcomes. Outcomes of LLN surgery after adequate training requires further research.</p

    Entwurf eines transparenten Vakuumisolationspaneels für Gewächshäuser nach Vorbild fraktaler Wabenstrukturen von Diatomeen

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    Die Beheizung macht 75 % des Energieverbrauchs in Gebäuden aus. Bei den hohen Energiesparanforderungen der Europäischen Union müssen hocheffiziente Wärmeisolationen entwickelt werden. Mit Vakuumisolationspaneelen können die höchsten Wärmewiderstände realisiert werden. Allerdings sind sie durch ihren Aufbau nicht transparent und gegenüber Belastungen sehr empfindlich. Dabei ist Wärmedämmung auch für funktionale Häuser mit transparenten Fassaden interessant. Für ein transparentes Vakuumisolationspaneel für Gewächshäuser muss eine stützende Kernstruktur gefunden werden, mit der das Paneel den Schnee und Windlasten, aber auch dem durch das Vakuum verursachten atmosphärischen Druck standhalten kann. Kieselalgen haben durch die Evolution hochstabile Leichtbaustrukturen zum Schutz vor Fressfeinden entwickelt, die als Vorbild für eine geeignete Stützstruktur dienen können. Die Gattung Isthmia besitzt fraktale Wabenstrukturen, die abstrahiert in hexagonaler Form und mit einer fraktalen Ebene für das Isolationspaneel verwendet werden. Um die Leistungsfähigkeit der Struktur zu testen wird ein parametrisches Finite-Elemente-Modell erstellt, das mit einem Evolutions-Algorithmus, unter Berücksichtigung der anzunehmenden Lasten, optimiert wird. Das beste Design aus der Optimierung kann den angenommen Lasten standhalten, hat aber verglichen mit einem klassischen Vakuumisolationspaneel eine 3,7-fach schlechtere Wärmedämmfähigkeit. Durch die fraktalen Waben ist das Isolationspaneel im Vergleich zu einer gleich bemessenen Struktur ohne fraktale Ebene zwar 14,6 % schwerer, hat dafür aber 52,2% weniger Verformung

    Measurements of droplets from singing and some other activities

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    We present initial results from measurements of exhaled droplets by two female singers during singing, speaking, laughing, and recitation of poetry. We also conducted measurements with a flute, a clarinet, a tuba, and only the tuba's mouthpiece. This small project is motivated by the current distancing restrictions for choirs, musicians, and actors. To be able to image and track droplets, we have developed and built a portable measurement set-up. We have detected droplets with diameters of approximately 50 μm and above. We found that for a single subject, the largest amount of droplets are produced during singing, but that laughing can produce a comparable number of droplets. Speaking and recitation of poetry do not produce as many droplets. We repeated exercises at varying distances and found that the number of detected droplets decreased rapidly with increasing distance. However, the relative height difference between people, e.g. in a stage setting, must be considered when determining how far a droplet of a given size and velocity can reach. Most droplets we detected follow a ballistic trajectory, and hit the ground after a distance of approximately 1 m. In case of the musical instruments, we did not detect droplets exiting a tuba and only few single droplets from a flute and a clarinet. A clarinet usually points downwards, such that droplets follow a downward trajectory and hit the ground after a short distance. The situation was different when the tubist used only the mouthpiece (that is, detached from the tuba) during warm-up while partially blocking the opening with a finger: in this case, many droplets were ejected from the mouthpiece. These followed ballistic trajectories at different speeds, with some droplets exiting the measurement volume. Two important limitations of this study are that (i) the sample size is very small, such that a statistical analysis is beyond our scope; and (ii) that we cannot draw conclusions about a possible risk of infection with COVID-19 when performing any of the said activities.Norges KorforbundpublishedVersio

    Measurements of droplets from singing and some other activities

    Get PDF
    We present initial results from measurements of exhaled droplets by two female singers during singing, speaking, laughing, and recitation of poetry. We also conducted measurements with a flute, a clarinet, a tuba, and only the tuba's mouthpiece. This small project is motivated by the current distancing restrictions for choirs, musicians, and actors. To be able to image and track droplets, we have developed and built a portable measurement set-up. We have detected droplets with diameters of approximately 50 μm and above. We found that for a single subject, the largest amount of droplets are produced during singing, but that laughing can produce a comparable number of droplets. Speaking and recitation of poetry do not produce as many droplets. We repeated exercises at varying distances and found that the number of detected droplets decreased rapidly with increasing distance. However, the relative height difference between people, e.g. in a stage setting, must be considered when determining how far a droplet of a given size and velocity can reach. Most droplets we detected follow a ballistic trajectory, and hit the ground after a distance of approximately 1 m. In case of the musical instruments, we did not detect droplets exiting a tuba and only few single droplets from a flute and a clarinet. A clarinet usually points downwards, such that droplets follow a downward trajectory and hit the ground after a short distance. The situation was different when the tubist used only the mouthpiece (that is, detached from the tuba) during warm-up while partially blocking the opening with a finger: in this case, many droplets were ejected from the mouthpiece. These followed ballistic trajectories at different speeds, with some droplets exiting the measurement volume. Two important limitations of this study are that (i) the sample size is very small, such that a statistical analysis is beyond our scope; and (ii) that we cannot draw conclusions about a possible risk of infection with COVID-19 when performing any of the said activities
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