397 research outputs found

    Subversion Over OpenNetInf and CCNx

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    We describe experiences and insights from adapting the Subversion version control system to use the network service of two information-centric networking (ICN) prototypes: OpenNetInf and CCNx. The evaluation is done using a local collaboration scenario, common in our own project work where a group of people meet and share documents through a Subversion repository. The measurements show a performance benefit already with two clients in some of the studied scenarios, despite being done on un-optimised research prototypes. The conclusion is that ICN clearly is beneficial also for non mass-distribution applications. It was straightforward to adapt Subversion to fetch updated files from the repository using the ICN network service. The adaptation however neglected access control which will need a different approach in ICN than an authenticated SSL tunnel. Another insight from the experiments is that care needs to be taken when implementing the heavy ICN hash and signature calculations. In the prototypes, these are done serially, but we see an opportunity for parallelisation, making use of current multi-core processors

    Experiments with Subversion Over OpenNetInf and CCNx

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    We describe experiences and insights from adapting the Subversion version control system to use the network service of two information-centric networking (ICN) prototypes: OpenNetInf and CCNx. The evaluation is done using a local collaboration scenario, common in our own project work where a group of people meet and share documents through a Subversion repository. The measurements show a performance benefit already with two clients in some of the studied scenarios, despite being done on un-optimised research prototypes. The conclusion is that ICN clearly is beneficial also for non mass-distribution applications

    Sustainable Development and Sustainability: Landscape Approach as a Practical Interpretation of Principles and Implementation Concepts

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    The situation for governors and managers of natural resources has increased in complexity. Previously it was enough to sustain the yields of wood, food and energy. Today, maintenance of ecosystem services, conservation of biodiversity, rural development and human wellbeing are new additional objectives. At the same time there are new risks and uncertainties linked to climate change, economic globalisation, energy security and water supply. Consequently, adaptive and holistic research, governance and management are needed. Landscape is a concept and framework that can be used as an approach to enhance implementation of policies about sustainable development as a societal process and sustainability as outcomes on the ground. For our analysis to define the landscape approach we used a hierarchical framework consisting of principles, concepts and initiatives; and included three principles defining SD and sustainability and five international concepts to analyze its implementation for our analysis to define landscape approach. We propose a practical operationalization that consists of five core attributes, (1) a sufficiently large area that matches management requirements and challenges to deliver desired goods, services and values, (2) multi-level and multi-sector stakeholder collaboration that promotes sustainable development as a social process, (3) commitment to and understanding of sustainability as an aim among stakeholders, (4) integrative knowledge production, and (5) sharing of experience, results and information, to develop local or tacit to general or explicit knowledge. Finally, we discuss the need for integrative research to study landscape approach concepts and what local initiatives using different concepts deliver on the ground

    Continuous gastric saline perfusion elicits cardiovascular responses in freshwater rainbow trout (Oncorhynchus mykiss)

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    When in seawater, rainbow trout (Oncorhynchus mykiss) drink to avoid dehydration and display stroke volume (SV) mediated elevations in cardiac output (CO) and an increased proportion of CO is diverted to the gastrointestinal tract as compared to when in freshwater. These cardiovascular alterations are associated with distinct reductions in systemic and gastrointestinal vascular resistance (R-Sys and R-GI, respectively). Although increased gastrointestinal blood flow (GBF) is likely essential for osmoregulation in seawater, the sensory functions and mechanisms driving the vascular resistance changes and other associated cardiovascular changes in euryhaline fishes remain poorly understood. Here, we examined whether internal gastrointestinal mechanisms responsive to osmotic changes mediate the cardiovascular changes typically observed in seawater, by comparing the cardiovascular responses of freshwater-acclimated rainbow trout receiving continuous (for 4 days) gastric perfusion with half-strength seawater (1/2 SW, similar to 17 ppt) to control fish (i.e., no perfusion). We show that perfusion with 1/2 SW causes significantly larger increases in CO, SV and GBF, as well as reductions in R-Sys and R-GI, compared with the control, whilst there were no significant differences in blood composition between treatments. Taken together, our data suggest that increased gastrointestinal luminal osmolality is sensed directly in the gut, and at least partly, mediates cardiovascular responses previously observed in SW acclimated rainbow trout. Even though a potential role of mechano-receptor stimulation from gastrointestinal volume loading in eliciting these cardiovascular responses cannot be excluded, our study indicates the presence of internal gastrointestinal milieu-sensing mechanisms that affect cardiovascular responses when environmental salinity changes

    Holistic methodological framework for assessing the benefits of delivering industrial excess heat to a district heating network

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    In Sweden, over 50% of building heating requirements are covered by district heating. Approximately 8% of the heat supply to district heating systems comes from excess heat from industrial processes. Many studies indicate that there is a potential to substantially increase this share, and policies promoting energy efficiency and greenhouse gas emissions reduction provide incentives to do this. Quantifying the medium and long-term economic and carbon footprint benefits of such investments is difficult because the background energy system against which new investments should be assessed is also expected to undergo significant change as a result of the aforementioned policies. Furthermore, in many cases, the district heating system has already invested or is planning to invest in non-fossil heat sources such as biomass-fueled boilers or CHP units. This paper proposes a holistic methodological framework based on energy market scenarios for assessing the long-term carbon footprint and economic benefits of recovering excess heat from industrial processes for use in district heating systems. In many studies of industrial excess heat, it is assumed that all emissions from the process plant are allocated to the main products, and none to the excess heat. The proposed methodology makes a distinction between unavoidable excess heat and excess heat that could be avoided by increased heat recovery at the plant site, in which case it is assumed that a fraction of the plant emissions should be allocated to the exported heat. The methodology is illustrated through a case study of a chemical complex located approximately 50 km from the city of Gothenburg on the West coast of Sweden, from which substantial amounts of excess heat could be recovered and delivered to heat to the city\u27s district heating network which aims to be completely fossil-free by 2030

    Energetic savings and cardiovascular dynamics of a marine euryhaline fish (Myoxocephalus scorpius) in reduced salinity

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    Few studies have addressed how reduced water salinity affects cardiovascular and metabolic function in marine euryhaline fishes, despite its relevance for predicting impacts of natural salinity variations and ongoing climate change on marine fish populations. Here, shorthorn sculpin (Myoxocephalus scorpius) were subjected to different durations of reduced water salinity from 33 to 15 ppt. Routine metabolic rate decreased after short-term acclimation (4-9 days) to 15 ppt, which corresponded with similar reductions in cardiac output. Likewise, standard metabolic rate decreased after acute transition (3 h) from 33 to 15 ppt, suggesting a reduced energetic cost of osmoregulation at 15 ppt. Interestingly, gut blood flow remained unchanged across salinities, which contrasts with previous findings in freshwater euryhaline teleosts (e.g., rainbow trout) exposed to different salinities. Although plasma osmolality, [Na+], [Cl-] and [Ca2+] decreased in 15 ppt, there were no signs of cellular osmotic stress as plasma [K+], [hemoglobin] and hematocrit remained unchanged. Taken together, our data suggest that shorthorn sculpin are relatively weak plasma osmoregulators that apply a strategy whereby epithelial ion transport mechanisms are partially maintained across salinities, while plasma composition is allowed to fluctuate within certain ranges. This may have energetic benefits in environments where salinity naturally fluctuates, and could provide shorthorn sculpin with competitive advantages if salinity fluctuations intensify with climate change in the future

    Varsel om uppsÀgning - Hur pÄverkas aktiekursen i hög- respektive lÄgkonjunktur?

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    Syfte: Denna uppsats har i syfte att utreda huruvida det gÄr att identifiera avvikande aktieavkastning hos svenska företag som varslar om uppsÀgning i hög- respektive lÄgkonjunktur. Uppsatsen syftar Àven till att tolka och jÀmföra marknadens vÀrdering av varsel om uppsÀgning i de skilda konjunkturlÀgena. Metod: Studien genomförs med hjÀlp av en eventstudiemetod för att undersöka hur marknaden reagerar vid tillkÀnnagivandet av varsel om uppsÀgning. Genomsnittlig avvikande avkastning samt ackumulerad genomsnittlig avvikande avkastning berÀknas och signifikanstestas utifrÄn formulerade hypoteser. Teoretisk referensram: Givet syftet för uppsatsen tillÀmpas den effektiva marknadshypotesen för att analysera empiriska resultat. Empiri och resultat: Kvantitativ data har anvÀnts i form av 41 observationer i högkonjunktur respektive 56 i lÄgkonjunktur, vilka frÀmst redovisas genom tabeller och grafer. Slutsats: Resultaten pÄvisar ett svagt negativ samband mellan varsel om uppsÀgning och aktiekursens utveckling i bÄde hög- samt lÄgkonjunktur pÄ kort sikt, dock utan statistisk signifikans. Detta ledde oss till slutsatsen att den svenska marknaden antingen Àr halvstarkt effektiv i det hÀr avseendet enligt effektiva marknadshypotesen eller att denna marknad Àr neutral i sin vÀrdering av den hÀr typen av information. Vidare tyder resultaten pÄ att marknaden tenderar att vÀrdera varsel om uppsÀgning mer negativt i lÄgkonjunktur. Emellertid kunde undersökningen ej frambringa statistiskt sÀkerstÀllda avvikelser, vilket medförde att inga generella slutsatser kring eventuella skillnader i marknadens reaktion pÄ kort sikt under de skilda konjunkturlÀgena kunde göras

    (68)Ga-labeled superparamagnetic iron oxide nanoparticles (SPIONs) for multi-modality PET/MR/Cherenkov luminescence imaging of sentinel lymph nodes.

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    The aim of this study was to develop (68)Ga-SPIONs for use as a single contrast agent for dynamic, quantitative and high resolution PET/MR imaging of Sentinel Lymph Node (SLN). In addition (68)Ga enables Cherenkov light emission which can be used for optical guidance during resection of SLN. SPIONs were labeled with (68)Ga in ammonium acetate buffer, pH 5.5. The labeling yield and stability in human serum were determined using instant thin layer chromatography. An amount of 0.07-0.1 mL (~5-10 MBq, 0.13 mg Fe) of (68)Ga-SPIONs was subcutaneously injected in the hind paw of rats. The animals were imaged at 0-3 h and 25 h post injection with PET/CT, 9.4 T MR and CCDbased Cherenkov optical systems. A biodistribution study was performed by dissecting and measuring the radioactivity in lymph nodes, kidneys, spleen, liver and the injection site. The labeling yield was 97.3 ± 0.05% after 15 min and the (68)Ga-SPIONs were stable in human serum. PET, MR and Cherenkov luminescence imaging clearly visualized the SLN. Biodistribution confirmed a high uptake of the (68)Ga-SPIONs within the SLN. We conclude that generator produced (68)Ga can be labeled to SPIONs. Subcutaneously injected (68)Ga-SPIONs can enhance the identification of the SLNs by combining sensitive PET and high resolution MR imaging. Clinically, hybrid PET/MR cameras are already in use and (68)Ga-SPIONs have a great potential as a single-dose, tri-modality agent for diagnostic imaging and potential Cherenkov luminescent guided resection of SLN
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