1,108 research outputs found

    The potential of energy crops in Poland and Germany

    Get PDF
    Biomass is broadly applicable in each energy sector and for a high variety of applications, but it is strongly restricted by its availability. Especially energy crop potentials are in heavy competition with food and fibre as well as nature conservation and construction activity, while the potential for additional cultivated land is constrained by technical and sustainability considerations. This paper presents a model HEKTOR which provides insight in the availability of agricultural land for the production of energy crops under sustainability restrictions on a national level. The model was developed for Poland and Germany. Its basic assumption is that agricultural land which is not used for food, raw materials, building activity and nature conservation is available to produce bioenergy. The model is founded on a broad base of statistical data on agricultural production and food demand and considers trends in the respective areas. HEKTOR is used to develop scenarios for the future availability of agricultural land for energy crop production. Two scenarios are presented: A 'business-as-usual’ scenario is compared to a sustainability scenario. On the one hand, the model quantifies the conflict of objectives between enhanced extensification in agriculture and increased area for nature conservation. On the other hand, the synergies in restricting built up area and increased mobilisation of agricultural residues are assessed. Our results show that the sustainable energy potential from agricultural biomass is strongly restricted for Germany compared to its energy demand whereas in Poland domestic agricultural biomass provides a much higher potential for energy supply, even if sustainability is comprehensively considered. For bioenergy from agricultural cultivation to remain a sustainable option in the energy sector, its influence on the food markets must be considered more thoroughly and a comprehensive approach to sustainable development in land use is a prerequisite

    Verification of Linear Optical Quantum Computing using Quantum Process Calculus

    Get PDF
    We explain the use of quantum process calculus to describe and analyse linear optical quantum computing (LOQC). The main idea is to define two processes, one modelling a linear optical system and the other expressing a specification, and prove that they are behaviourally equivalent. We extend the theory of behavioural equivalence in the process calculus Communicating Quantum Processes (CQP) to include multiple particles (namely photons) as information carriers, described by Fock states or number states. We summarise the theory in this paper, including the crucial result that equivalence is a congruence, meaning that it is preserved by embedding in any context. In previous work, we have used quantum process calculus to model LOQC but without verifying models against specifications. In this paper, for the first time, we are able to carry out verification. We illustrate this approach by describing and verifying two models of an LOQC CNOT gate.Comment: In Proceedings EXPRESS/SOS 2014, arXiv:1408.127

    Transcript of My Father’s Heroics

    Get PDF
    This story is an excerpt from a longer interview that was collected as part of the Launching through the Surf: The Dory Fleet of Pacific City project. In this story, Sid Fisher recounts how his father, Walt Fisher, saved him from rolling his dory

    Bioenergie versus Ökolandbau: Flächenkonkurrenz als Entwicklungshemmnis?

    Get PDF
    To satisfy national sustainability targets in Germany, both bioenergy and organic farming claim a growing area of farmland. Analyses with a land use model and ac-companying expert interviews show, how the competition for land is growing in certain regions. A restricted area potential for energy crops – even with an ever intensifying farming opposes targets for an increasing share of land for organic agriculture and nature conservation. Thus there is a need for policy action, to discuss and solve this goal conflict. An ongoing study currently develops strategies for two selected German regions for a more ecologically compatible bioenergy production

    Empowering Retinal Gene Therapy with a Specific Promoter for Human Rod and Cone ON-Bipolar Cells

    Get PDF
    Optogenetic gene therapy holds promise to restore high-quality vision in blind patients and recently reached clinical trials. Although the ON-bipolar cells, the first retinal interneurons, make the most attractive targets for optogenetic vision restoration, they have remained inaccessible to human gene therapy due to the lack of a robust cell-specific promoter. We describe the design and functional evaluation of 770En_454P(hGRM6), a human GRM6 gene-derived, short promoter that drives strong and highly specific expression in both the rod- and cone-type ON-bipolar cells of the human retina. Expression also in cone-type ON-bipolar cells is of importance, since the cone-dominated macula mediates high-acuity vision and is the primary target of gene therapies. 770En_454P(hGRM6)-driven middle-wave opsin expression in ON-bipolar cells achieved lasting restoration of high visual acuity in the rd1 mouse model of late retinal degeneration. The new promoter enables precise manipulation of the inner retinal network and paves the way for clinical application of gene therapies for high-resolution optogenetic vision restoration, raising hopes of significantly improving the life quality of people suffering from blindness

    Medical Management versus PACK-CXL in Dogs with Infectious Keratitis: A Randomized Controlled Trial Protocol

    Full text link
    Infectious keratitis is a common and painful disease, usually caused by bacteria in dogs. Brachycephalic breeds are at increased risk. Despite medical therapy, enzymatic corneal melting can lead to ulcer perforation and globe loss. Treatment alternatives are needed due to an increase in antibiotic resistance and growing popularity of brachycephalic dogs. Photoactivated Chromophore for Keratitis-Corneal Cross-linking (PACK-CXL) reduces enzymatic collagenolysis and damages multiple targets within microorganisms, resulting in corneal tissue stabilization and elimination of bacteria, irrespective of their antibiotic resistance status. A randomized controlled trial providing evidence of PACK-CXL effectiveness in dogs is lacking. We aim to determine whether PACK-CXL is a viable alternative to conventional medical therapy for canine infectious keratitis. Two hundred-and-seventy client-owned dogs with presumed infectious keratitis will be allocated to two equally sized treatment groups (PACK-CXL or medical therapy) in a masked, randomized, controlled, multicenter trial in eleven clinics. The primary outcome measure is treatment success defined as complete epithelial closure within 28 days. The sample size is based on a group sequential design with two interim analyses, which will be overseen by a Data Safety and Monitoring Board. Ethical approvals have been obtained. The study protocol is preregistered at preclinicaltrials.eu. Publishing trial protocols improves study reproducibility and reduces publication bias

    What do they do all day? Exploring the complexity of early childhood teachers' work

    Get PDF
    A discussion on the findings of a study with 22 teachers . Using time use diaries they wrote down their activities of a given day. A taxonomy developed by Charles Sturt University in Australia was used to code and analyse the activities. This is a report on the initial pilot with the next step to use a mobile app on a wider group of teachers in Aotearoa New Zealand

    Population Ecology and Epidemiology of Sea Lice in Canadian Waters

    Get PDF
    Sea lice are found on farmed and wild fish on both the west coast and east coast of Canada. The predominant species on both coasts is referred to as Lepeophtheirus salmonis but indications are that the two groups are genetically different. Caligus species are also found on both coasts, these too are different species: Caligus clemensi and C. elongatus, respectively. There has been extensive work on sea lice on both wild and farmed fish over the last decade. Research indicates that L. salmonis, commonly referred to as the salmon louse; may have a broader host range than commonly thought, infecting species such as the three-spine stickleback. The role of farmed salmon, particularly farmed Atlantic Salmon, as potential reservoirs of L. salmonis is accepted. What is still debated is the effect of sea lice infections on wild salmon populations, and whether the establishment of farm level treatment thresholds is the most appropriate method to manage the situation. There is indication that various Pacific salmon species have different tolerances to both L. salmonis and C. clemensi and the role of other non-salmon species in the ecology and epidemiology of sea lice still needs to be better researched. Published work on sea lice on farmed salmon on the East Coast is more limited; research on wild Atlantic Salmon even more so. This Research Document was presented and reviewed as part of the Canadian Science Advisory Secretariat (CSAS) National peer-review meeting, Sea Lice Monitoring and Non-Chemical Measures, held in Ottawa, Ontario, September 25-27, 2012. The objective of this peer-review meeting was to assess the state of knowledge and provide scientific advice on sea lice management measures, monitoring and interactions between cultured and wild fish

    Contribution of nanoclays to the barrier properties of a model proton exchange membrane for fuel cell application

    Get PDF
    peer reviewedaudience: researcherDirect methanol fuel cells (DMFCs) that use a proton exchange membrane (PEM) as electrolyte, is a promising alternative source of energy for the future. However, methanol crossover from the anodic side to the cathodic one is a major problem in DMFC. Proper dispersion of layered silicates within the fuel cell membrane has been proposed as a strategy for improving the barrier properties of the membrane. The validity of this approach has been tested in case of a model membrane consisting of phosphotungstic acid doped poly(vinyl alcohol). A solvent casting technique has been used, which allows the nanofiller to be delaminated by an ultrasonic pre-treatment, as confirmed by TEM and XRD analysis. The layered silicates have a favourable impact on the methanol permeability, whose the decrease overcompensates some loss in ionic conductivity
    corecore