Geological challenges and geohazard monitoring of a mega engineering hydropower project in Iceland

Publisher's version (útgefin grein).Geohazards must be considered, assessed and mitigated for all life-cycle phases of most mega infrastructure projects. This paper presents a unique mega engineering project, the 600 MW Kárahnjúkar Hydropower Project in Iceland. The construction site presented several interesting and complex geological and geophysical conditions, such as an unexpected discovery of an active fault in the foundation of the main dam (mega dam) and earthquake activity in a nearby volcanic zone caused by a subsurface volcanic intrusion during the first impoundment. The related apprehensions included predictions of: Persistent movements and opening of faults in the dam foundation causing excessive leakage, large reservoir induced crustal deformation that could trigger volcanic eruption or near field earthquake action such as reservoir triggered earthquakes that might affect the safety of the dam structures. The approach taken to resolve these apprehensions was to undertake specific investigations, assessments and monitoring, through a novel multidisciplinary organization. The focus of the paper is on describing the development and implementation of a holistic multi-source geohazard monitoring program for the main reservoir, Hálslón Reservoir and its dams. The discussion starts with a definition of what constitutes monitoring of geohazards within the framework of the project. This is followed by an outline of the monitoring networks implemented comprising instruments monitoring seismicity (micro-seismic stations and strong-motion instrumentation), crustal movements (continuous global positioning systems and benchmarks), fault movement (extensometers, joint and crack meters), groundwater elevation and leakage. Finally, a summary of key results from the geohazard monitoring is given. The geological challenges and related apprehensions are linked to the relevant research and investigations carried out, the monitoring networks installed, and the results produced, which demonstrate that during and after the first impoundment the key monitored processes were all within the pre-set limits. The case presented is relevant for current and future mega engineering projects as it demonstrates that a monitoring program set up to guard operational safety in the spirit of potential failure mode analysis, will provide important information on geo-environmental impact of a mega engineering project, not only for scientific interest but also for public information.The monitoring network and the work of the multidisciplinary ESG overseeing the program was funded by Landsvirkjun (The National Power Company of Iceland). The contribution of Petur Ingolfsson, Freysteinn Sigmundsson, Kristjan Sigmundsson, Steinunn Jakobsdottir, Halldor Geirsson, Benedikt Ofeigsson, Victor Helgason, Agust Guomundsson, Haukur Johannesson, Johann Helgason, Pall Einarsson, Vilbergur Kristinsson, Ragnar Sigbjornsson, Markus Rennen and the designer the Karahnjukar Engineering Joint Venture (KEJV), in planning and implementing a successful research and monitoring program is acknowledged. The authors are grateful for access to figures, information and data from the above parties as well as from Landsvirkjun, the Icelandic Meteorological Office, and KEJV through Verkis Iceland."Peer Reviewed

Flow distortion recorded by sonic anemometers on a long-span bridge: Towards a better modelling of the dynamic wind load in full-scale

Publisher's version (útgefin grein)The turbulent wind field around a suspension bridge deck is studied using eleven months of full-scale records from sonic anemometers mounted above the girder. Using the mean and turbulent velocity characteristics, we demonstrate that the bridge structure can significantly distort the flow. More precisely, the friction velocity, the variance of the fluctuating vertical velocity and the mean wind incidence angle are underestimated on the downstream side of the deck. The local topography is also found to influence the flow in a non-negligible way, such that turbulence characteristics differ significantly from those observed in flat and homogeneous terrains. For a hexagonal girder with a width to height ratio B/H approximate to 4.5, deck-induced flow distortion is still observed on the downwind side of the girder at a height above the road equal to 3.6H. This further supports the idea that wind measurements from a suspension bridge should rely on anemometers on both sides of the deck to mitigate flow distortion. The improved flow description combined with high-resolution acceleration records of the deck provides a simulation of the wind-induced response of the bridge with a level of accuracy that is rarely achieved in full-scale. In particular, the limits of a wind model based on flat terrain assumption as well as the limits of the strip theory are highlighted by the recorded data and the improved modelling of the bridge buffeting responseStatens vegvesen"Peer Reviewed

Fatal Hemothorax Caused by Pseudomesotheliomatous Carcinoma of the Lung

We present a case of a poorly differentiated pseudomesotheliomatous carcinoma originating in the lung, which was manifested with the distinctly rare complication of massive true hemothorax and persistent blood loss that proved rapidly fatal in spite of surgery. Pseudomesotheliomatous carcinoma of the lung and neoplasia-associated hemothorax are reviewed and discussed

Outcomes of patients with perforated colon cancer:A systematic review

Introduction: Perforated colon cancer (PCC) is a distinct clinical entity with implications for treatment and prognosis, however data on PCC seems scarce. The aim of this systematic review is to provide a comprehensive overview of the recent literature on clinical outcomes of PCC. Materials and methods: A systematic literature search of MEDLINE (PubMed), Embase, Cochrane library and Google scholar was performed. Studies describing intentionally curative treatment for patients with PCC since 2010 were included. The main outcome measures consisted of short-term surgical complications and long-term oncological outcomes. Results: Eleven retrospective cohort studies were included, comprising a total of 2696 PCC patients. In these studies, various entities of PCC were defined. Comparative studies showed that PCC patients as compared to non-PCC patients have an increased risk of 30-day mortality (8–33% vs 3–5%), increased post-operative complications (33–56% vs 22–28%), worse overall survival (36–40% vs 48–65%) and worse disease-free survival (34–43% vs 50–73%). Two studies distinguished free-perforations from contained perforations, revealing that free-perforation is associated with significantly higher 30-day mortality (19–26% vs 0–10%), lower overall survival (24–28% vs 42–64%) and lower disease-free survival (15% vs 53%) as compared to contained perforations. Conclusion: Data on PCC is scarce, with various PCC entities defined in the studies included. Heterogeneity of the study population, definition of PCC and outcome measures made pooling of the data impossible. In general, perforation, particularly free perforation, seems to be associated with a substantial negative effect on outcomes in colon cancer patients undergoing surgery. Better definition and description of the types of perforation in future studies is essential, as outcomes seem to differ between types of PCC and might require different treatment strategies.</p

Size and depth of residual tumor after neoadjuvant chemoradiotherapy in rectal cancer – implications for the development of new imaging modalities for response assessment

With the shift towards organ preserving treatment strategies in rectal cancer it has become increasingly important to accurately discriminate between a complete and good clinical response after neoadjuvant chemoradiotherapy (CRT). Standard of care imaging techniques such as CT and MRI are well equipped for initial staging of rectal tumors, but discrimination between a good clinical and complete response remains difficult due to their limited ability to detect small residual vital tumor fragments. To identify new promising imaging techniques that could fill this gap, it is crucial to know the size and invasion depth of residual vital tumor tissue since this determines the requirements with regard to the resolution and imaging depth of potential new optical imaging techniques. We analyzed 198 pathology slides from 30 rectal cancer patients with a Mandard tumor regression grade 2 or 3 after CRT that underwent surgery. For each patient we determined response pattern, size of the largest vital tumor fragment or bulk and the shortest distance from the vital tumor to the luminal surface. The response pattern was shrinkage in 14 patients and fragmentation in 16 patients. For both groups combined, the largest vital tumor fragment per patient was smaller than 1mm for 38% of patients, below 0.2mm for 12% of patients and for one patient as small as 0.06mm. For 29% of patients the vital tumor remnant was present within the first 0.01mm from the luminal surface and for 87% within 0.5mm. Our results explain why it is difficult to differentiate between a good clinical and complete response in rectal cancer patients using endoscopy and MRI, since in many patients submillimeter tumor fragments remain below the luminal surface. To detect residual vital tumor tissue in all patients included in this study a technique with a spatial resolution of 0.06mm and an imaging depth of 8.9mm would have been required. Optical imaging techniques offer the possibility of detecting majority of these cases due to the potential of both high-resolution imaging and enhanced contrast between tissue types. These techniques could thus serve as a complimentary tool to conventional methods for rectal cancer response assessment.</p

Cutaneous squamous cell carcinoma is associated with Lynch syndrome: widening the spectrum of Lynch syndrome-associated tumours

Cellular mechanisms in basic and clinical gastroenterology and hepatolog

Measurements of Surface-Layer Turbulence in a Wide Norwegian Fjord Using Synchronized Long-Range Doppler Wind Lidars

Three synchronized pulsed Doppler wind lidars were deployed from May 2016 to June 2016 on the shores of a wide Norwegian fjord called Bjornafjord to study the wind characteristics at the proposed location of a planned bridge. The purpose was to investigate the potential of using lidars to gather information on turbulence characteristics in the middle of a wide fjord. The study includes the analysis of the single-point and two-point statistics of wind turbulence, which are of major interest to estimate dynamic wind loads on structures. The horizontal wind components were measured by the intersecting scanning beams, along a line located 25m above the sea surface, at scanning distances up to 4.6km. For a mean wind velocity above 8m.s(-1), the recorded turbulence intensity was below 0.06 on average. Even though the along-beam spatial averaging leads to an underestimated turbulence intensity, such a value indicates a roughness length much lower than provided in the European standard EN 1991-1-4:2005. The normalized spectrum of the along-wind component was compared to the one provided by the Norwegian Petroleum Industry Standard and the Norwegian Handbook for bridge design N400. A good overall agreement was observed for wave-numbers below 0.02m(-1). The along-beam spatial averaging in the adopted set-up prevented a more detailed comparison at larger wave-numbers, which challenges the study of wind turbulence at scanning distances of several kilometres. The results presented illustrate the need to complement lidar data with point-measurement to reduce the uncertainties linked to the atmospheric stability and the spatial averaging of the lidar probe volume. The measured lateral coherence was associated with a decay coefficient larger than expected for the along-wind component, with a value around 21 for a mean wind velocity bounded between 10m.s(-1) and 14m.s(-1), which may be related to a stable atmospheric stratification.The measurements were performed with the support from the Norwegian Public Road Administration. We are indebted to Claus Brian Munk Pedersen and Soren William Lund from the Technical University of Denmark, as well as Jarle Berge from the University of Stavanger, for their assistance during the installation and/or dismantling of the lidar equipment. Finally, we are grateful to Kjeller Vindteknikk for providing the data recorded on the met-mast on the island of Ospoya."Peer Reviewed

Inhibition of fatty acid synthesis induces differentiation and reduces tumor burden in childhood neuroblastoma

Many metabolic pathways, including lipid metabolism, are rewired in tumors tosupport energy and biomass production and to allow adaptation to stressful en-vironments. Neuroblastoma is the second deadliest solid tumor in children. Ge-netic aberrations, as the amplification of theMYCN-oncogene, correlate stronglywith disease progression. Yet, there are only a few molecular targets successfullyexploited in the clinic. Here we show that inhibition of fatty acid synthesis led toincreased neural differentiation and reduced tumor burden in neuroblastomaxenograft experiments independently ofMYCN-status. This was accompaniedby reduced levels of the MYCN or c-MYC oncoproteins and activation of ERKsignaling. Importantly, the expression levels of genes involved inde novofattyacid synthesis showed prognostic value for neuroblastoma patients. Our findingsdemonstrate that inhibition ofde novofatty acid synthesis is a promising pharma-cological intervention strategy for the treatment of neuroblastoma indepen-dently ofMYCN-status

Size and depth of residual tumor after neoadjuvant chemoradiotherapy in rectal cancer – implications for the development of new imaging modalities for response assessment

With the shift towards organ preserving treatment strategies in rectal cancer it has become increasingly important to accurately discriminate between a complete and good clinical response after neoadjuvant chemoradiotherapy (CRT). Standard of care imaging techniques such as CT and MRI are well equipped for initial staging of rectal tumors, but discrimination between a good clinical and complete response remains difficult due to their limited ability to detect small residual vital tumor fragments. To identify new promising imaging techniques that could fill this gap, it is crucial to know the size and invasion depth of residual vital tumor tissue since this determines the requirements with regard to the resolution and imaging depth of potential new optical imaging techniques. We analyzed 198 pathology slides from 30 rectal cancer patients with a Mandard tumor regression grade 2 or 3 after CRT that underwent surgery. For each patient we determined response pattern, size of the largest vital tumor fragment or bulk and the shortest distance from the vital tumor to the luminal surface. The response pattern was shrinkage in 14 patients and fragmentation in 16 patients. For both groups combined, the largest vital tumor fragment per patient was smaller than 1mm for 38% of patients, below 0.2mm for 12% of patients and for one patient as small as 0.06mm. For 29% of patients the vital tumor remnant was present within the first 0.01mm from the luminal surface and for 87% within 0.5mm. Our results explain why it is difficult to differentiate between a good clinical and complete response in rectal cancer patients using endoscopy and MRI, since in many patients submillimeter tumor fragments remain below the luminal surface. To detect residual vital tumor tissue in all patients included in this study a technique with a spatial resolution of 0.06mm and an imaging depth of 8.9mm would have been required. Optical imaging techniques offer the possibility of detecting majority of these cases due to the potential of both high-resolution imaging and enhanced contrast between tissue types. These techniques could thus serve as a complimentary tool to conventional methods for rectal cancer response assessment

Current controversies in TNM for the radiological staging of rectal cancer and how to deal with them: results of a global online survey and multidisciplinary expert consensus

Objectives: To identify the main problem areas in the applicability of the current TNM staging system (8th ed.) for the radiological staging and reporting of rectal cancer and provide practice recommendations on how to handle them. Methods: A global case-based online survey was conducted including 41 image-based rectal cancer cases focusing on various items included in the TNM system. Cases reaching < 80% agreement among survey respondents were identified as problem areas and discussed among an international expert panel, including 5 radiologists, 6 colorectal surgeons, 4 radiation oncologists, and 3 pathologists. Results: Three hundred twenty-one respondents (from 32 countries) completed the survey. Sixteen problem areas were identified, related to cT staging in low-rectal cancers, definitions for cT4b and cM1a disease, definitions for mesorectal fascia (MRF) involvement, evaluation of lymph nodes versus tumor deposits, and staging of lateral lymph nodes. The expert panel recommended strategies on how to handle these, including advice on cT-stage categorization in case of involvement of different layers of the anal canal, specifications on which structures to include in the definition of cT4b disease, how to define MRF involvement by the primary tumor and other tumor-bearing structures, how to differentiate and report lymph nodes and tumor deposits on MRI, and how to anatomically localize and stage lateral lymph nodes. Conclusions: The recommendations derived from this global survey and expert panel discussion may serve as a practice guide and support tool for radiologists (and other clinicians) involved in the staging of rectal cancer and may contribute to improved consistency in radiological staging and reporting. Key Points: • Via a case-based online survey (incl. 321 respondents from 32 countries), we identified 16 problem areas related to the applicability of the TNM staging system for the radiological staging and reporting of rectal cancer. • A multidisciplinary panel of experts recommended strategies on how to handle these problem areas, including advice on cT-stage categorization in case of involvement of different layers of the anal canal, specifications on which structures to include in the definition of cT4b disease, how to define mesorectal fascia involvement by the primary tumor and other tumor-bearing structures, how to differentiate and report lymph nodes and tumor deposits on MRI, and how to anatomically localize and stage lateral lymph nodes. • These recommendations may serve as a practice guide and support tool for radiologists (and other clinicians) involved in the staging of rectal cancer and may contribute to improved consistency in radiological staging and reporting