The role of Nuclear Factor κB in the cellular response to different radiation qualities

Radiation is currently one of the most important limiting factors for manned space flight. During such missions, there is a constant exposure to low doses of galactic cosmic radiation and in particular high-energy heavy ions. Together this is associated with an increased cancer risk which currently cannot be sufficiently reduced by shielding. As such, cellular radiation response needs to be further studied in order to improve risk estimation and develop appropriate countermeasures. It has been shown that exposure of human cells to accelerated heavy ions, in fluences that can be reached during long-term missions, leads to activation of the Nuclear Factor κB (NF-κB) pathway. Heavy ions with a linear energy transfer (LET) of 90 to 300 keV/μm were most effective in activating NF-κB. NF-κB as an important modulating factor in the cellular radiation response could improve cellular survival after heavy ion exposure, thereby influencing the cancer risk of astronauts. The NF-κB pathway may be a potential pharmacological target in the mitigation of radiation response during space missions; such as the prevention of massive cell death after high dose irradiation (acute effects), in addition to neoplastic cell transformation during chronic low-dose exposure (late effects). The aim of this work was to examine the role of NF-κB in the cellular response to space-relevant radiation. Firstly, NF-κB activation in human embryonic kidney cells (HEK) after exposure to different radiation qualities and quantities was investigated. Key elements of different NF-κB sub-pathways were chemically inhibited to analyze their role in NF-κB activation induced by low and high LET ionizing radiation. Finally a cell line, stably transfected with a plasmid coding for a short-hairpin RNA (shRNA) for a knockdown of the NF-κB subunit RelA, was established to assess the role of RelA in the cellular response to space-relevant radiation. The knockdown was verified on several levels and the cell line was characterized concerning proliferation, cell cycle progression and gene expression. Additionally, the effects of the RelA knockdown on cell cycle progression, cellular survival and gene expression after exposure to low and high LET radiation were investigated. It was shown that activation of NF-κB depends on radiation quality and quantity. Experiments with chemical inhibitors revealed that NF-κB activation by ionizing radiation is strictly ATM dependent and degradation of the NF-κB inhibitor IκB by the proteasome is essential for both the classical and genotoxic stress-induced NF-κB pathway. Absence of NF-κB dimers containing RelA resulted in a prolonged lag-phase but did not affect cell cycle progression significantly in untreated cells. After irradiation, a dose and radiation quality dependent arrest in the G2 phase of the cell cycle occurred and also upon downregulation of RelA expression. RelA knockdown resulted in higher sensitivity of HEK cells to the killing effect of X-irradiation. In contrast, RelA knockdown did not further reduce the cellular survival after heavy ion exposure. Further, NF-κB target genes were not inducible in the RelA knockdown cell line. NF-κB-dependent gene expression rely on radiation dose and LET. Chemokine expression (e.g. CXCL1, 2, 8 and 10) was induced in a proportional manner to radiation quality and quantity, emphasizing the role of NF-κB in the bystander effect. These NF-κB regulated genes are interesting targets for countermeasure development against the effects of space radiation

On the role of fatty acid composition in photoacclimation of seaweeds

In their variable environments, marine macroalgae rely on efficient photoacclimatory and -protective mechanisms in order to minimize oxidative stress-induced cellular damages. Thereby, adjustments in photosynthetic pigments (also xanthophyll cycle), phlorotannins and antioxidants were confirmed to feature a high significance. Further, it was indicated that modulations in fatty acid composition (degree of saturation, chain length) might also form part of photoacclimation and -protection, both along vertical and seasonal gradients. The latter acclimation response might not only help the algae to optimize their membrane fluidities, but also to create ideal environments for the functioning of the xanthophyll cycle under variable environmental conditions. Generally, adjustments in fatty acid profiles were shown to be highly species-specific, with both light and temperature having a strong impact on this response variable. The findings of this dissertation might help to predict macroalgal responses towards challenging environmental conditions, which is crucial under ongoing climate change, and might be useful for commercial applications

Steps for Prioritizing Academic Advising: A Small-School Case Study

This paper presents a case study of the steps taken to prioritize academic advising at a small, four-year, liberal arts university. Assessment data from several sources and an advising task force shaped the plan for changing the importance and culture of academic advising within the institution

Forschungsförderung in der Erziehungswissenschaft durch die DFG. Bilanz nach acht Jahren Arbeit des Fachkollegiums

Das Fachkollegium "Erziehungswissenschaft" der Deutschen Forschungsgemeinschaft hat seine Arbeit [...] 2004 aufgenommen [...]. [Es] vertritt die Belange des Faches in allen Programmen der DFG und wirkt an allen Förderentscheidungen mit. [Förderstatistiken der Jahre 2004-2011 zeigen] einen tendenziellen, aber nicht sehr hohen Anstieg des Mittelbedarfs wie auch der Bewilligungen [...] (DIPF/Orig.

Is Social Media like an Onion?: Exploring the Social Penetration Theory as an Explanation for Viral Responses to Intimate Self-Disclosures

A recent public FB post about a personal experience with depression went viral within a week. Within a week this post was reposted on numerous media outlets, and shared by others nearly 500,000 times. This post skipped to the third, affective stage, of the Social Penetration Theory

Thoracoscopic Left Atrial Appendage Ligation Complicated by Persistent Left Superior Vena Cava

We herein report a 64 year-old male who had an incidental finding of a persistent left superior vena cava (SVC) revealed by intraoperative transesophageal echocardiography (TEE) during a Maze procedure with left atrial appendage ligation. During the intraoperative TEE, an incidental dilated coronary sinus \u3e 1.1 cm was noted which prompted further evaluation and aided in our ultimate diagnosis. Consequently, significant additional surgical dissection and manipulation were required to isolate the left upper pulmonary vein. This case report reviews the anatomy and embryology of a persistent left SVC, discusses its clinical implications, and identifies surgical considerations for treatment

GPU-enabled pavement distress image classification in real time

Pavement assessment is a crucial process for the maintenance of municipal roads. However, the detection of pavement distress is usually performed either manually or offline, which is not only time-consuming and subjective, but also results in an enormous amount of data being stored persistently before processing. State-of-the-art pavement image processing methods executed on a CPU are not able to analyse pavement images in real time. To compensate this limitation of the methods, we propose an automated approach for pavement distress detection. In particular, GPU implementations of a noise removal, a background correction and a pavement distress detection method were developed. The median filter and the top-hat transform are used to remove noise and shadows in the images. The wavelet transform is applied in order to calculate a descriptor value for classification purposes. The approach was tested on 1549 images. The results show that real-time pre-processing and analysis are possible

GPU-enabled pavement distress image classification in real time

Pavement assessment is a crucial process for the maintenance of municipal roads. However, the detection of pavement distress is usually performed either manually or offline, which is not only time-consuming and subjective, but also results in an enormous amount of data being stored persistently before processing. State-of-the-art pavement image processing methods executed on a CPU are not able to analyse pavement images in real time. To compensate this limitation of the methods, we propose an automated approach for pavement distress detection. In particular, GPU implementations of a noise removal, a background correction and a pavement distress detection method were developed. The median filter and the top-hat transform are used to remove noise and shadows in the images. The wavelet transform is applied in order to calculate a descriptor value for classification purposes. The approach was tested on 1549 images. The results show that real-time pre-processing and analysis are possible