RescUSim and IPython: An environment for offshore emergency preparedness planning

Emergency preparedness is crucial for oil and gas operators. While accidents in this industry are commonly connected to oil spill disasters, helicopter accidents are, in terms of incidence rates, a more grave concern in Norway. A recent helicopter accident near Bergen has brought this subject back into focus. We introduce RescUSim, a simulator for rescue missions after offshore helicopter accidents, which is implemented as an open source library with bindings for the Python language. We discuss the modules in the existing Python ecosystem that are used for data preparation and analysis. We show how RescUSim and the interactive computing environment IPython can join forces to provide a tool for planning rescue preparedness for oil and gas related offshore activities

RescUSim and IPython : an environment for offshore emergency preparedness planning

Emergency preparedness is crucial for oil and gas operators. While accidents in this industry are commonly connected to oil spill disasters, helicopter accidents are, in terms of incidence rates, a more grave concern in Norway. A recent helicopter accident near Bergen has brought this subject back into focus. We introduce RescUSim, a simulator for rescue missions after offshore helicopter accidents, which is implemented as an open source library with bindings for the Python language. We discuss the modules in the existing Python ecosystem that are used for data preparation and analysis. We show how RescUSim and the interactive computing environment IPython can join forces to provide a tool for planning rescue preparedness for oil and gas related offshore activities.publishedVersio

Auswirkungen der Zufriedenheit berufstätiger Mütter auf die sozio-emotionale Entwicklung ihrer Kinder

Diese Studie gibt Aufschluss über die Zufriedenheit berufstätiger Mütter und die sozio-emotionale Entwicklung ihrer drei- bis sechsjährigen Kinder. Mögliche Unterschiede in der kindlichen sozio-emotionalen Entwicklung der Kinder, in Abhängigkeit der Zufriedenheit der Mütter sollen aufgedeckt werden. Die Zufriedenheit wurde mittels FLZ und FLL in gekürzter Form erhoben. Selbsterstellte Fragen bilden den Teil zur Erhebung der Belastung der Mütter. Weiters wurde den Müttern der Verhaltensbeurteilungsbogen (3 – 6), sowie der WET – Elternfragebogen zur Einschätzung der Selbständigkeit vorgegeben. Zusätzlich wurde mit 40 Kindern der WET durchgeführt. In den drei gebildetet Zufriedenheitstypen konnten keine signifikanten Unterschiede, hinsichtlich der kindlichen sozio-emotionalen Entwicklung festgestellt werden. Tendenzen geben Hinweise, dass sich Unzufriedenheit und Belastung der Mütter in Form von internalen Verhaltensproblemen auf die Kinder auswirkt. Mütter, die in der Rollenvielfalt eine Ressource sehen sind zufriedener und haben Kinder mit einer positiveren Entwicklung. Genügend gute Kinderbetreuungsmöglichkeiten und familienfreundliche Arbeitsplätze unterstützen eine gute Vereinbarkeit der Rollen Familie und Beruf

Characterization of novel members of the LEM-domain containing protein family in mammalian cells

Der Zellkern, das charakteristische Merkmal eukaryotischer Zellen, wird von einer Kernhülle eingeschlossen, die aus einer doppelten Lipidmembran mit eingefügten Kernporenkomplexen und einer filamentösen Kernlamina in mehrzelligen Arten, die der inneren Kernmembran anliegt, besteht. Mehrere integrierte innere Kernmembranenproteine enthalten ein spezifisches Strukturmotiv, die sogenannte LEM-Domäne (LAP2, Emerin, MAN1), die das DNA-bindende Molekül BAF (barrier-to-autointegration factor) bindet. Mutationen in LEM Proteinen wurden mit humanen Pathologien assoziiert, die in der heterogenen Gruppe der sogenannten "Envelopathien" zusammengefaßt werden. Zwei neue LEM Proteine, LEM2 und LEM3, wurden in der vorliegenden Dissertation identifiziert und analysiert. LEM2 ist ubiquitär in Geweben und Zelltypen exprimiert und ist sowohl bezüglich der Primärsequenz als auch der Domänen-Topologie eng mit MAN1 verwandt. Komplementations-assays zeigten, daß Funktionen von LEM2 von der Hefe bis zum Menschen konserviert sind. In Säugetierzellen lokalisiert LEM2 an der inneren Kernhülle, interagiert direkt mit Lamin A/C und BAF und benötigt A-typ Lamine für die Lokalisation an der Kernmembran. Die Lamin A/C-interagierende Region wurde auf einen Teil des N-Terminus eingegrenzt, wohingegen der C Terminus ein DNA-Bindungsmotif enthält. Letzteres ist essentiell für überexprimierte LEM2-Fragmente um Komplexe an der Kernhülle zu formen, die Lamin A und Lamin A-assoziierte Proteine rekrutieren können, jedoch Lamin B und Lamin B-assoziierte Protein exkludieren. Unsere bisherigen Daten weisen auf eine Rolle von LEM2 in der räumlichen Organisation von Komplexen an der Kernhülle und in der Chromatinorganisation an der Kernperipherie hin. LEM3 wurde vor allem in hämatopoietischen Geweben gefunden, so etwa im Knochenmark, Thymus und Milz, sowie in Lymphoma. Eine Analyse der LEM3 Domänenstruktur zeigte eine Gruppe von Ankyrin-Repeats am N-terminus des Proteins sowie ein evolutionär konserviertes GIY-YIG Motif innerhalb des C-Terminus welches zuvor in verschiedenen Proteinen mit Nukleasefunktion beschrieben wurde. Desweiteren habe ich zwei LEM3 Splice-Isoformen identifiziert bei welchen Teile der LEM Domäne fehlen, wobei diese im Gegensatz zum vollständigen LEM3 BAF nicht binden können. LEM3 enthält keine Transmembran-Regionen und wurde als Kern/Zytoplasma-"Shuttling"-Protein identifiziert. In menschlichen Zellen kolokalisiert LEM3 mit cytoplasmatischen Aktin-Filamenten, während es nach pharmakologischer Inhibierung des Kernexports in nukleären "Splicing-Speckles" zu finden ist. Ektopische Expression von LEM3 führte zu einer Mislokalisation von BAF, Zellzyklusarrest und Aktivierung des ATM abhängigen DNA-Schädigungs-Signalweges. Wir postulieren eine Funktion von LEM3 in der DNA Rekombination oder im DNA Reparatur Signalweg.The nucleus in eukaryotic cells is enclosed by a nuclear envelope consisting of an inner and outer membrane, nuclear pore complexes, and in metazoans a filamentous lamina meshwork underlying the inner nuclear membrane. The lamina consists of intermediate filament-type proteins, the lamins, and numerous integral inner nuclear membrane proteins. Among these, a family of membrane proteins contain a conserved structural motif, called LEM domain (LAP2, Emerin, MAN1), which interacts with the DNA binding molecule BAF (barrier-to-autointegration factor). LEM proteins have been implicated in chromatin organization and gene expression control and have been linked to a heterogeneous group of inherited human diseases, collectively termed "envelopathies". This PhD thesis describes the identification and initial characterization of two novel LEM proteins, LEM2 and LEM3. LEM2 is ubiquitously expressed in many tissues and cell types and is closely related to MAN1 in primary sequence and domain topology. Complementation assays revealed that LEM2 is functionally conserved from yeast to man. In mammalian cells, it localizes at the inner nuclear membrane, interacts directly with A-type lamins and with BAF, and requires lamin A/C for nuclear envelope localization. The lamin A/C interaction domain was mapped to the N-terminus, while the C-terminus contains a conserved DNA binding motif. The latter was required for the ability of overexpressed LEM2 fragments to form patches at the nuclear envelope that recruit lamin A and lamin A-binding proteins, but exclude lamin B and associated proteins. Our data suggest a role of LEM2 in the spatial organization of protein complexes at the nuclear envelope and in chromatin organization at the nuclear periphery. LEM3 is primarily expressed in hematopoietic tissues such as bone marrow, thymus and spleen, and in lymphoma-derived cell lines, suggesting a B-cell related function. Analysis of LEM3 domain topology revealed a cluster of Ankyrin repeats at the N-terminus and a conserved C terminal GIY-YIG motif previously described in proteins with nuclease activity. I identified two LEM3 splice-isoforms lacking parts of the LEM domain. Unlike these isoforms full length LEM3 bound BAF. LEM3 misses a transmembrane domain and was found to shuttle between nucleoplasm and cytoplasm. In human cells ectopic LEM3 co-localizes with cytoplasmic actin filaments, while it is in nuclear splicing speckles upon pharmacological inhibition of nuclear export. Ectopic expression of LEM3 in the nucleus causes a mislocalization of BAF, cell cycle arrest, and activation of the ATM-dependent DNA damage pathway. We propose that LEM3 may be involved in DNA recombination or repair pathways

A hydrogel model of the human blood-brain barrier using differentiated stem cells

An in vitro model of the human blood-brain barrier was developed, based on a collagen hydrogel containing astrocytes, overlaid with a monolayer of endothelium, differentiated from human induced pluripotent stem cells (hiPSCs). The model was set up in transwell filters allowing sampling from apical and basal compartments. The endothelial monolayer had transendothelial electrical resistance (TEER) values >700Ω.cm2 and expressed tight-junction markers, including claudin-5. After differentiation of hiPSCs the endothelial-like cells expressed VE-cadherin (CDH5) and von-Willebrand factor (VWF) as determined by immunofluorescence. However, electron microscopy indicated that at set-up (day 8 of differentiation), the endothelial-like cells still retained some features of the stem cells, and appeared immature, in comparison with primary brain endothelium or brain endothelium in vivo. Monitoring showed that the TEER declined gradually over 10 days, and transport studies were best carried out in a time window 24-72hrs after establishment of the model. Transport studies indicated low permeability to paracellular tracers and functional activity of P-glycoprotein (ABCB1) and active transcytosis of polypeptides via the transferrin receptor (TFR1)

LEM-3 is a midbody-tethered DNA nuclease that resolves chromatin bridges during late mitosis

Chromosome segregation and genome maintenance require the removal of DNA bridges that link chromosomes just before cells divide. Here the authors show that the LEM-3/Ankle1 nuclease processes DNA bridges before cells divide and define a previously undescribed genome integrity mechanism

Nuclear envelope protein Lem2 is required for mouse development and regulates MAP and AKT kinases

The nuclear lamina, along with associated nuclear membrane proteins, is a nexus for regulating signaling in the nucleus. Numerous human diseases arise from mutations in lamina proteins, and experimental models for these disorders have revealed aberrant regulation of various signaling pathways. Previously, we reported that the inner nuclear membrane protein Lem2, which is expressed at high levels in muscle, promotes the differentiation of cultured myoblasts by attenuating ERK signaling. Here, we have analyzed mice harboring a disrupted allele for the Lem2 gene (Lemd2). No gross phenotypic defects were seen in heterozygotes, although muscle regeneration induced by cardiotoxin was delayed. By contrast, homozygous Lemd2 knockout mice died by E11.5. Although many normal morphogenetic hallmarks were observed in E10.5 knockout embryos, most tissues were substantially reduced in size. This was accompanied by activation of multiple MAP kinases (ERK1/2, JNK, p38) and AKT. Knockdown of Lem2 expression in C2C12 myoblasts also led to activation of MAP kinases and AKT. These findings indicate that Lemd2 plays an essential role in mouse embryonic development and that it is involved in regulating several signaling pathways. Since increased MAP kinase and AKT/mTORC signaling is found in other animal models for diseases linked to nuclear lamina proteins, LEMD2 should be considered to be another candidate gene for human disease

LAP2 Is Widely Overexpressed in Diverse Digestive Tract Cancers and Regulates Motility of Cancer Cells

BACKGROUND: Lamina-associated polypeptides 2 (LAP2) is a nuclear protein that connects the nuclear lamina with chromatin. Although its critical roles in genetic disorders and hematopoietic malignancies have been described, its expression and roles in digestive tract cancers have been poorly characterized. METHODS: To examine the expression of LAP2 in patient tissues, we performed immunohistochemistry and real-time PCR. To examine motility of cancer cells, we employed Boyden chamber, wound healing and Matrigel invasion assays. To reveal its roles in metastasis in vivo, we used a liver metastasis xenograft model. To investigate the underlying mechanism, a cDNA microarray was conducted. RESULTS: Immunohistochemistry in patient tissues showed widespread expression of LAP2 in diverse digestive tract cancers including stomach, pancreas, liver, and bile duct cancers. Real-time PCR confirmed that LAP2β is over-expressed in gastric cancer tissues. Knockdown of LAP2β did not affect proliferation of most digestive tract cancer cells except pancreatic cancer cells. However, knockdown of LAP2β decreased motility of all tested cancer cells. Moreover, overexpression of LAP2β increased motility of gastric and pancreatic cancer cells. In the liver metastasis xenograft model, LAP2β increased metastatic efficacy of gastric cancer cells and mortality in tested mice. cDNA microarrays showed the possibility that myristoylated alanine-rich C kinase substrate (MARCKS) and interleukin6 (IL6) may mediate LAP2β-regulated motility of cancer cells. CONCLUSIONS: From the above results, we conclude that LAP2 is widely overexpressed in diverse digestive tract cancers and LAP2β regulates motility of cancer cells and suggest that LAP2β may have utility for diagnostics and therapeutics in digestive tract cancers