Marine Oil Spills

Major oil spills attract the attention of the public and the media. This was especially the case after the Deepwater Horizon spill. In recent years, this attention has created a global awareness of the risks of oil spills and the damage they do to the environment. Oil is a necessity in our industrial society, however, and a major component of our lifestyle. This means that the risk of major spills continues as does the interest in spills. The Deepwater Horizon spill began a new series of scientific studies that have greatly increased our understanding of oil spills. This book contains 10 such studies. These studies vary from toxicity studies to social studies of human reaction to spills and risk. Importantly, the book is a sampling of important new topics that have become important after the Deepwater Horizon spill. These new topics include new chemical and tracing techniques, new risk perception techniques, perspectives on human health and spills, and discussion on new fuels. This book makes a significant contribution to the understanding of facets of spills and explores 10 very different facets of oil spills

Performance Analysis of the R290 Variable Geometry Gas Ejector Application for Other Refrigerants

Ejector refrigeration systems are promising alternative to standard vapour compression refrigeration systems. They can be driven with low-grade heat or solar systems, which make them even more renewable solution aligned with global energy transition. By implementing the controllable ejector, it can adapt to variable operating conditions, ensuring the high efficiency of both the device and the overall performance of the system. However, as it is fluid-driven device, its geometry has to be designed for particular fluid and typically requires redesigning when being applied for new applications. The R290 variable geometry gas ejector has been thoroughly tested for various spindle positions which ensured its highly efficient operation at different conditions. In this study, the same geometry was tested for other natural refrigerants of similar thermodynamic properties, i.e.R600a and R1270. The CFD analysis was based on a set of operating points for ejector-based air conditioning system working during the summer period with characteristic temperatures at evaporator and condenser. The controllable ejector was simulated for all the points with similar motive and suction nozzle parameters and the critical temperature at the outlet was determined. The analysis showed that the ejector can be used with other refrigerants maintaining high efficiency without any changes in geometry but for lower number of spindle positions. The obtained critical temperature indicates that with all the tested refrigerants the ejector-based cycle is able to work for cooling purposes during typical summer conditions for a wide range of temperatures

Resultate nach radikaler Prostatektomie bei Patienten mit einem Prostatakarzinom Gleason 7-10

Patienten mit einem Gleason-Score 8-10 Prostatakarzinom galten und gelten teilweise auch heute unter anderem aufgrund hoher Rezidivraten und geringen tumorspezifischen Überlebens als weniger geeignete Kandidaten für eine radikale Prostatektomie als primäre Therapiemaßnahme. Ziel dieser Arbeit war die Analyse von tumorspezifischer Überlebenszeit und PSA-rezidivfreiem Überleben bei Patienten mit einem Gleason-Score 8-10 Prostatakarzinom nach radikaler Prostatektomie. Zum Vergleich wurden auch Patienten mit einem Gleason-Score von 7 Prostatakarzinom erfasst. Insgesamt wurden 489 Patienten aus zwei Patientenkollektiven der Universitätsklinik Marburg (n=106) resp. Köln (n=383) mit einer mittleren Follow up-Zeit von 23,1 ± 14,7 Monaten nachbeobachtet. 415 Patienten (84,9%) wiesen einen postoperativen Gleason-Score von 7, 32 (6,5%) und 42 Patienten (8,6%) einen postoperativen Gleason-Score von 8 resp. 9/10 auf. 53,3% der erfassten Studienpatienten wurden zusätzlich adjuvant therapiert (ADT, Radiatio, andere), worunter sich vorwiegend Patienten mit einem pN+-Status bzw. einem pT-Status ≥ pT3b befanden. Tumorspezifische Überlebenszeit und PSA-rezidivfreies Überleben wurden mittels Kaplan-Meier Methode/Logranktest berechnet. Das tumorspezifische Gesamtüberleben betrug 96,3% (5 verstorbene Patienten), das PSA-rezidivfreie Gesamtüberleben lag bei 54,5% (71 Patienten mit PSA Rezidiv). 243 Patienten (49,7%) wiesen ein Stadium pT2, 237 (48,5%) und 9 Patienten (1,8%) ein Stadium pT3 resp. pT4 auf. Patienten mit einem pT-Stadium < pT3b zeigten ein tumorspezifisches Überleben von 99,4%, wobei die Gleason-Score-spezifischen Unterschiede bezüglich des tumorspezifischen Überlebens hier aufgehoben waren. Präoperatives PSA und pN-Status verfehlten die Signifikanz als Prognosefaktoren knapp. Die radikale Prostatektomie scheint in frühen Tumorstadien mit Wahrung der Organgrenzen auch bei Patienten mit entdifferenzierten Prostatakarzinomen eine sinnvolle Behandlungsmethode zu sein. Patienten mit weiter fortgeschrittenen Prostatakarzinomen benötigen multimodale Therapiekonzepte. Es bedarf längerer Follow up-Zeiten sowie zusätzlicher Studienpatienten, um die vorgestellten Resultate zu verifizieren und weitere Prognosefaktoren herauszuarbeiten

Effects of Dispersants and Biosurfactants on Crude-Oil Biodegradation and Bacterial Community Succession

This study evaluated the effects of three commercial dispersants (Finasol OSR 52, Slickgone NS, Superdispersant 25) and three biosurfactants (rhamnolipid, trehalolipid, sophorolipid) in crude-oil seawater microcosms. We analysed the crucial early bacterial response (1 and 3 days). In contrast, most analyses miss this key period and instead focus on later time points after oil and dispersant addition. By focusing on the early stage, we show that dispersants and biosurfactants, which reduce the interfacial surface tension of oil and water, significantly increase the abundance of hydrocarbon-degrading bacteria, and the rate of hydrocarbon biodegradation, within 24 h. A succession of obligate hydrocarbonoclastic bacteria (OHCB), driven by metabolite niche partitioning, is demonstrated. Importantly, this succession has revealed how the OHCB Oleispira, hitherto considered to be a psychrophile, can dominate in the early stages of oil-spill response (1 and 3 days), outcompeting all other OHCB, at the relatively high temperature of 16 °C. Additionally, we demonstrate how some dispersants or biosurfactants can select for specific bacterial genera, especially the biosurfactant rhamnolipid, which appears to provide an advantageous compatibility with Pseudomonas, a genus in which some species synthesize rhamnolipid in the presence of hydrocarbons

Dimension reduction for systems with slow relaxation

We develop reduced, stochastic models for high dimensional, dissipative dynamical systems that relax very slowly to equilibrium and can encode long term memory. We present a variety of empirical and first principles approaches for model reduction, and build a mathematical framework for analyzing the reduced models. We introduce the notions of universal and asymptotic filters to characterize `optimal' model reductions for sloppy linear models. We illustrate our methods by applying them to the practically important problem of modeling evaporation in oil spills.Comment: 48 Pages, 13 figures. Paper dedicated to the memory of Leo Kadanof

Performance Analysis of the R290 Variable Geometry Gas Ejector Application for Other Refrigerants

Ejector refrigeration systems are promising alternative to standard vapour compression refrigeration systems. They can be driven with low-grade heat or solar systems, which make them even more renewable solution aligned with global energy transition. By implementing the controllable ejector, it can adapt to variable operating conditions, ensuring the high efficiency of both the device and the overall performance of the system. However, as it is fluid-driven device, its geometry has to be designed for particular fluid and typically requires redesigning when being applied for new applications. The R290 variable geometry gas ejector has been thoroughly tested for various spindle positions which ensured its highly efficient operation at different conditions. In this study, the same geometry was tested for other natural refrigerants of similar thermodynamic properties, i.e.R600a and R1270. The CFD analysis was based on a set of operating points for ejector-based air conditioning system working during the summer period with characteristic temperatures at evaporator and condenser. The controllable ejector was simulated for all the points with similar motive and suction nozzle parameters and the critical temperature at the outlet was determined. The analysis showed that the ejector can be used with other refrigerants maintaining high efficiency without any changes in geometry but for lower number of spindle positions. The obtained critical temperature indicates that with all the tested refrigerants the ejector-based cycle is able to work for cooling purposes during typical summer conditions for a wide range of temperatures

Cellular inhibitor of apoptosis 1 (cIAP-1) degradation by caspase 8 during TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis.

TNF-related apoptosis-inducing ligand (TRAIL) is a potential chemotherapeutic agent with high selectivity for malignant cells. Many tumors, however, are resistant to TRAIL cytotoxicity. Although cellular inhibitors of apoptosis 1 and 2 (cIAP-1 and -2) are often over-expressed in cancers, their role in mediating TRAIL resistance remains unclear. Here, we demonstrate that TRAIL-induced apoptosis of liver cancer cells is associated with degradation of cIAP-1 and X-linked IAP (XIAP), whereas cIAP-2 remains unchanged. Lower concentrations of TRAIL causing minimal or no apoptosis do not alter cIAP-1 or XIAP protein levels. Silencing of cIAP-1 expression, but not XIAP or cIAP-2, as well as co-treatment with a second mitochondrial activator of caspases (SMAC) mimetic (which results in rapid depletion of cIAP-1), sensitizes the cells to TRAIL. TRAIL-induced loss of cIAP-1 and XIAP requires caspase activity. In particular, caspase 8 knockdown stabilizes both cIAP-1 and XIAP, while caspase 9 knockdown prevents XIAP, but not cIAP-1 degradation. Cell-free experiments confirmed cIAP-1 is a substrate for caspase 8, with likely multiple cleavage sites. These results suggest that TRAIL-mediated apoptosis proceeds through caspase 8-dependent degradation of cIAP-1. Targeted depletion of cIAP-1 by SMAC mimetics in conjunction with TRAIL may be beneficial for the treatment of human hepatobiliary malignancies

miR-25 targets TNF-related apoptosis inducing ligand (TRAIL) death receptor-4 and promotes apoptosis resistance in cholangiocarcinoma.

It has been established that microRNA expression and function contribute to phenotypic features of malignant cells, including resistance to apoptosis. Although targets and functional roles for a number of microRNAs have been described in cholangiocarcinoma, many additional microRNAs dysregulated in this tumor have not been assigned functional roles. In this study, we identify elevated miR-25 expression in malignant cholangiocarcinoma cell lines as well as patient samples. In cultured cells, treatment with the Smoothened inhibitor, cyclopamine, reduced miR-25 expression, suggesting Hedgehog signaling stimulates miR-25 production. Functionally, miR-25 was shown to protect cells against TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. Correspondingly, antagonism of miR-25 in culture sensitized cells to apoptotic death. Computational analysis identified the TRAIL Death Receptor-4 (DR4) as a potential novel miR-25 target, and this prediction was confirmed by immunoblot, cell staining, and reporter assays. CONCLUSION: These data implicate elevated miR-25 levels in the control of tumor cell apoptosis in cholangiocarcinoma. The identification of the novel miR-25 target DR4 provides a mechanism by which miR-25 contributes to evasion of TRAIL-induced cholangiocarcinoma apoptosis