Stepwise Green Investment under Policy Uncertainty

We analyse how market price and policy uncertainty, in the form of random provision or retraction of a subsidy, interact to affect the optimal time of investment and the size of a renewable energy (RE) project that can be completed in either a single (lumpy investment) or multiple stages (stepwise investment). The subsidy takes the form of a fixed premium on top of the electricity price, and, therefore, investment is subject to electricity price uncertainty. We show that the risk of a permanent retraction (provision) of a subsidy increases (decreases) the incentive to invest, yet lowers (raises) the amount of installed capacity, and that this result is more pronounced as the size of the subsidy increases. Additionally, we show that increasing the number of policy interventions lowers the expected value of a subsidy and the size of the project. Furthermore, we illustrate that, although an increase in the size of a subsidy lowers the relative value of the stepwise investment strategy, the expected value of a lumpy investment strategy is still lower than that of stepwise investment

A homologous production system for Trichoderma reesei secreted proteins in a cellulase-free background

Recent demands for the production of biofuels from lignocellulose led to an increased interest in engineered cellulases from Trichoderma reesei or other fungal sources. While the methods to generate such mutant cellulases on DNA level are straightforward, there is often a bottleneck in their production since a correct posttranslational processing of these enzymes is needed to obtain highly active enzymes. Their production and subsequent enzymatic analysis in the homologous host T. reesei is, however, often disturbed by the concomitant production of other endogenous cellulases. As a useful alternative, we tested the production of cellulases in T. reesei in a genetic background where cellulase formation has been impaired by deletion of the major cellulase transcriptional activator gene xyr1. Three cellulase genes (cel7a, cel7b, and cel12a) were expressed under the promoter regions of the two highly expressed genes tef1 (encoding translation elongation factor 1-alpha) or cdna1 (encoding the hypothetical protein Trire2:110879). When cultivated on d-glucose as carbon source, the Δxyr1 strain secreted all three cellulases into the medium. Related to the introduced gene copy number, the cdna1 promoter appeared to be superior to the tef1 promoter. No signs of proteolysis were detected, and the individual cellulases could be assayed over a background essentially free of other cellulases. Hence this system can be used as a vehicle for rapid and high-throughput testing of cellulase muteins in a homologous background

Real time contrast enhanced ultrasonography in detection of liver metastases from gastrointestinal cancer

Background: Contrast enhanced ultrasound (CEUS) is an imaging technique which appeared on the market around the year 2000 and proposed for the detection of liver metastases in gastrointestinal cancer patients, a setting in which accurate staging plays a significant role in the choice of treatment. Methods: A total of 109 patients with colorectal (n = 92)or gastric cancer prospectively underwent computed tomography (CT) scan and conventional US evaluation followed by real time CEUS. A diagnosis of metastases was made by CT or, for lesions not visibile at CT, the diagnosis was achieved by histopathology or by a malignant behavior during follow-up. Results: Of 109 patients, 65 were found to have metastases at presentation. CEUS improved sensitivity in metastatic livers from 76.9% of patients (US) to 95.4% (p < 0.01), while CT scan reached 90.8% (p = n.s. vs CEUS, p < 0.01 vs US). CEUS and CT were more sensitive than US also for detection of single lesions (87 with US, 122 with CEUS, 113 with CT). In 15 patients (13.8%), CEUS revealed more metastases than CT, while CT revealed more metastases than CEUS in 9 patients (8.2%) (p = n.s.). Conclusion: CEUS is more sensitive than conventional US in the detection of liver metastases and could be usefully employed in the staging of patients with gastrointestinal cancer. Findings at CEUS and CT appear to be complementary in achieving maximum sensitivity. © 2007 Piscaglia et al; licensee BioMed Central Ltd

Lebens- und Krankheitsgeschichte: Der VDS1 Fragebogen in der klinischen und wissenschaftlichen Anwendung am Beispiel der Kindheit von Patienten mit Depression und Angstkrankheiten

Der VDS1 Fragebogen zur Lebens- und Krankheitsgeschichte dient der Erfassung der Biographie von ambulanten Psychotherapiepatienten, vornehmlich für den Bericht an den Gutachter, aber auch für die Fallkonzeption. Durch seine Struktur und die vollständige Erfassung aller relevanten Fakten kann er sowohl klinisch als auch wissenschaftlich eingesetzt werden. Hier wird eine Studie vorgestellt, in der zunächst allgemeine Besonderheiten der Kindheit von Psychotherapiepatienten nachgegangen wurde und dann Depressions- und Angstpatienten hinsichtlich wichtiger Marker ihrer Kindheit verglichen wurden (Frustration zentraler Bedürfnisse der Kindheit, Umgang mit kindlichen Emotionen, Elternbeziehung, psychische Belastung der Eltern). Konsequenzen für Prävention und Psychotherapie werden formuliert

E-038 CTA Protocol Optimization for Improved Stent Visualization

Introduction/purpose Evaluation of stents using noninvasive imaging can be difficult. Artefact from the metallic struts often limits visibility within the stent on computed tomography angiograms (CTA). Special techniques developed for visualization of cardiac stents using CTA can be adapted for cervical and intracranial stent evaluation. Materials and methods All studies were performed on a 64 slice GE Discovery 750HD CT scanner (GE Healthcare, Little Chalfont, Buckinghamshire, United Kingdom). The standard arterial phase imaging protocol is performed with 100 mL of contrast administered at a rate of 5 ml/sec. Scan acquisition is triggered when contrast arrives in the aortic arch. Scan coverage extends from the carina to the vertex of the head. Slice thickness is 0.625. Pitch is 1.375:1. Rotation time is 0.5 sec. Tube voltage is 120 kv with a dynamic tube current ranging from 200–350 mA. The raw images are then reconstructed through the stent using a bone plus algorithm at 0.625 mm x 0.3 mm and a field of view of 20 mm. Three fellowship trained neuroradiologists compared the standard CTA sequences with those optimised for visualization of the stent. For each stent, the reader described the patency of the stent (patent, occluded, or mild/moderate/severe stenosis) and their confidence level in their interpretation (high, moderate, or low confidence). Each reader then subjectively determined if they felt the stent CTA was beneficial. Results The optimised stent protocol uses a harder reconstruction algorithm, small field of view, and thin cuts to optimise the view of content within the stent. All readers agreed that the stent CTA was useful and improved their confidence in stents that were less than 2.5 mm in diameter. Stenosis was routinely overestimated in stents less than 2.5 mm using the standard protocol. In the representative case, the patient presented with stroke like symptoms attributable to the vascular distribution of the stent. On the original CTA (Figure 1a), the stent was believed to be occluded. However, after reconstructing the image using the stent protocol, the stent was found to be widely patent (Figure 1b). Abstract E-038 Figure 1 Example of a normal CTA protocol compared with the optimised stent protocol Conclusions With the use of a 64 slice CT scanner and a protocol adopted from the cardiac literature, it may be possible to adequately assess the patency of cervical and intracranial stents using CTA. Disclosures C. Durst: None. R. Starke: None. P. Norton: None. K. Hagspiel: None. J. Gingras: None. H. Hixson: None. K. Liu: None. R. Crowley: None. J. Gaughen: 2; C; Stryker, Covidien, Microvention. M. Jensen: 2; C; Covidien. A. Evans: 2; C; Covidien, Stryker