26 research outputs found

    Evaluation of hydropower upgrade projects - a real options approach

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    When evaluating whether to refurbish existing hydropower plants or invest in a new power plant, there are two important aspects to take into consideration. These are the capacity chosen for the production facilities and the timing of the investment. This paper presents an investment decision support framework for hydropower producers with production facilities due for restoration. The producer can choose between refurbishing existing power plants and investing in a new production facility. A real options framework is proposed to support the investment decision. Using a case from Norsk Hydro ASA, a Norwegian hydropower producer, we employ the framework to evaluate the investment opportunities. Our main contribution is an approach that combines hydropower scheduling and real options valuation, and the results from our analysis suggest feasible investment strategies for Norsk Hydro ASA.Electricity price uncertainty; reservoir management; hydroelectric scheduling; investment under uncertainty; electricity markets

    Evaluation of hydropower upgrade projects - a real options approach

    Get PDF
    When evaluating whether to refurbish existing hydropower plants or invest in a new power plant, there are two important aspects to take into consideration. These are the capacity chosen for the production facilities and the timing of the investment. This paper presents an investment decision support framework for hydropower producers with production facilities due for restoration. The producer can choose between refurbishing existing power plants and investing in a new production facility. A real options framework is proposed to support the investment decision. Using a case from Norsk Hydro ASA, a Norwegian hydropower producer, we employ the framework to evaluate the investment opportunities. Our main contribution is an approach that combines hydropower scheduling and real options valuation, and the results from our analysis suggest feasible investment strategies for Norsk Hydro ASA

    Evaluation of hydropower upgrade projects - a real options approach

    Get PDF
    When evaluating whether to refurbish existing hydropower plants or invest in a new power plant, there are two important aspects to take into consideration. These are the capacity chosen for the production facilities and the timing of the investment. This paper presents an investment decision support framework for hydropower producers with production facilities due for restoration. The producer can choose between refurbishing existing power plants and investing in a new production facility. A real options framework is proposed to support the investment decision. Using a case from Norsk Hydro ASA, a Norwegian hydropower producer, we employ the framework to evaluate the investment opportunities. Our main contribution is an approach that combines hydropower scheduling and real options valuation, and the results from our analysis suggest feasible investment strategies for Norsk Hydro ASA

    Possible hominin footprints from the late Miocene (c. 5.7 Ma) of Crete?

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    © 2017 The Geologists' Association. We describe late Miocene tetrapod footprints (tracks) from the Trachilos locality in western Crete (Greece), which show hominin-like characteristics. They occur in an emergent horizon within an otherwise marginal marine succession of Messinian age (latest Miocene), dated to approximately 5.7 Ma (million years), just prior to the Messinian Salinity Crisis. The tracks indicate that the trackmaker lacked claws, and was bipedal, plantigrade, pentadactyl and strongly entaxonic. The impression of the large and non-divergent first digit (hallux) has a narrow neck and bulbous asymmetrical distal pad. The lateral digit impressions become progressively smaller so that the digital region as a whole is strongly asymmetrical. A large, rounded ball impression is associated with the hallux. Morphometric analysis shows the footprints to have outlines that are distinct from modern non-hominin primates and resemble those of hominins. The interpretation of these footprints is potentially controversial. The print morphology suggests that the trackmaker was a basal member of the clade Hominini, but as Crete is some distance outside the known geographical range of pre-Pleistocene hominins we must also entertain the possibility that they represent a hitherto unknown late Miocene primate that convergently evolved human-like foot anatomy

    Tyrosine Phosphorylation of Rac1: A Role in Regulation of Cell Spreading

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    Rac1 influences a multiplicity of vital cellular- and tissue-level control functions, making it an important candidate for targeted therapeutics. The activity of the Rho family member Cdc42 has been shown to be modulated by tyrosine phosphorylation at position 64. We therefore investigated consequences of the point mutations Y64F and Y64D in Rac1. Both mutations altered cell spreading from baseline in the settings of wild type, constitutively active, or dominant negative Rac1 expression, and were accompanied by differences in Rac1 targeting to focal adhesions. Rac1-Y64F displayed increased GTP-binding, increased association with βPIX, and reduced binding with RhoGDI as compared with wild type Rac1. Rac1-Y64D had less binding to PAK than Rac1-WT or Rac1-64F. In vitro assays demonstrated that Y64 in Rac1 is a target for FAK and Src. Taken together, these data suggest a mechanism for the regulation of Rac1 activity by non-receptor tyrosine kinases, with consequences for membrane extension

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
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