841 research outputs found

    The role of intermediaries in the transition to district heating

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    For those countries, such as the UK, in which district heating and cooling has previously played little role in the energy system, the technology often struggles to break through the numerous and complex barriers to its introduction in the context of liberalised energy markets and competition with incumbent technologies such as natural gas networks. Progress is often slow and best practice is yet to be established. ‘Intermediaries’ are actors who facilitate knowledge sharing and build actor networks to enable the introduction of new technologies. This paper uses a case study of the UK to explore where and how the activities of these intermediary actors are currently supporting district heating development. An innovative method called a ‘decision theatre’ was used to collect empirical evidence from a range of local stakeholders involved in district heating projects. This method, which took place in the format of a group workshop, enables understanding of the interactions between stakeholders through each stage of the district heating development process. Lessons are drawn from this case study with regard to how intermediary activities can support the development of district heating in areas with little previous history of such systems. Three geographical scales of intermediary activity are identified (local, regional and national) as having different roles in enabling delivery of new district heating projects. Interactions between the three scales and how their roles might change as the sector develops are explored. The paper will highlight implications of the study for policymakers. In particular, a role is identified for intermediaries in creating a supportive institutional and policy environment that can enable development of large-scale, strategic networks

    Realising the social benefits of district heating through strategic planning

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    Affordability, low carbon and security are hailed as the three critical characteristics of our future energy system. In this respect, district heating offers towns and cities many attractive characteristics. In particular, under the right governance models, it can offer social benefits by lowering energy costs and alleviating fuel poverty. This research uses the case study of the UK, a country where less than 2% of heat is delivered by district heating, but where levels of fuel poverty are a significant challenge. UK local authorities play an active role in the early planning stages of district heating and many are aiming to alleviate fuel poverty with these projects. The results show that the full variety of actor motivations are not reflected within their decision criteria; although local authorities aspire to take a strategic planning role, this is not reflected in the mapping tools that they use in feasibility work. We propose a more flexible approach to mapping for strategic planning and consider its role in bringing forward DH schemes that reduce fuel poverty

    Trophy hunting certification

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    Adaptive certification is the best remaining option for the trophy hunting industry in Africa to demonstrate sustainable and ethical hunting practices that benefit local communities and wildlife conservation

    Conformational Space and Stability of ETD Charge Reduction Products of Ubiquitin

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    Owing to its versatility, electron transfer dissociation (ETD) has become one of the most commonly utilized fragmentation techniques in both native and non-native top-down mass spectrometry. However, several competing reactions—primarily different forms of charge reduction—occur under ETD conditions, as evidenced by the distorted isotope patterns usually observed. In this work, we analyze these isotope patterns to compare the stability of nondissociative electron transfer (ETnoD) products, specifically noncovalent c/z fragment complexes, across a range of ubiquitin conformational states. Using ion mobility, we find that more extended states are more prone to fragment release. We obtain evidence that for a given charge state, populations of ubiquitin ions formed either directly by electrospray ionization or through collapse of more extended states upon charge reduction, span a similar range of collision cross-sections. Products of gas-phase collapse are, however, less stabilized towards unfolding than the native conformation, indicating that the ions retain a memory of previous conformational states. Furthermore, this collapse of charge-reduced ions is promoted if the ions are ‘preheated’ using collisional activation, with possible implications for the kinetics of gas-phase compaction

    Predicting Impaired Extinction of Traumatic Memory and Elevated Startle

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    Emotionally traumatic experiences can lead to debilitating anxiety disorders, such as phobias and Post-Traumatic Stress Disorder (PTSD). Exposure to such experiences, however, is not sufficient to induce pathology, as only up to one quarter of people exposed to such events develop PTSD. These statistics, combined with findings that smaller hippocampal size prior to the trauma is associated with higher risk of developing PTSD, suggest that there are pre-disposing factors for such pathology. Because prospective studies in humans are limited and costly, investigating such pre-dispositions, and thus advancing understanding of the genesis of such pathologies, requires the use of animal models where predispositions are identified before the emotional trauma. Most existing animal models are retrospective: they classify subjects as those with or without a PTSD-like phenotype long after experiencing a traumatic event. Attempts to create prospective animal models have been largely unsuccessful.Here we report that individual predispositions to a PTSD-like phenotype, consisting of impaired rate and magnitude of extinction of an emotionally traumatic event coupled with long-lasting elevation of acoustic startle responses, can be revealed following exposure to a mild stressor, but before experiencing emotional trauma. We compare, in rats, the utility of several classification criteria and report that a combination of criteria based on acoustic startle responses and behavior in an anxiogenic environment is a reliable predictor of a PTSD-like phenotype.There are individual predispositions to developing impaired extinction and elevated acoustic startle that can be identified after exposure to a mildly stressful event, which by itself does not induce such a behavioral phenotype. The model presented here is a valuable tool for studying the etiology and pathophysiology of anxiety disorders and provides a platform for testing behavioral and pharmacological interventions that can reduce the probability of developing pathologic behaviors associated with such disorders

    Functional Effects of Parasites on Food Web Properties during the Spring Diatom Bloom in Lake Pavin: A Linear Inverse Modeling Analysis

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    This study is the first assessment of the quantitative impact of parasitic chytrids on a planktonic food web. We used a carbon-based food web model of Lake Pavin (Massif Central, France) to investigate the effects of chytrids during the spring diatom bloom by developing models with and without chytrids. Linear inverse modelling procedures were employed to estimate undetermined flows in the lake. The Monte Carlo Markov chain linear inverse modelling procedure provided estimates of the ranges of model-derived fluxes. Model results support recent theories on the probable impact of parasites on food web function. In the lake, during spring, when ‘inedible’ algae (unexploited by planktonic herbivores) were the dominant primary producers, the epidemic growth of chytrids significantly reduced the sedimentation loss of algal carbon to the detritus pool through the production of grazer-exploitable zoospores. We also review some theories about the potential influence of parasites on ecological network properties and argue that parasitism contributes to longer carbon path lengths, higher levels of activity and specialization, and lower recycling. Considering the “structural asymmetry” hypothesis as a stabilizing pattern, chytrids should contribute to the stability of aquatic food webs

    Sources of scientific creativity: participant observation of a public research institute in Korea

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    This study aims to find the factors of scientists' creative thoughts by observing directly their laboratories in Korea Research Institute of Chemical Technology (KRICT). The participant observation was performed for 5 months from December 2013 through April 2014, and the research object was the lab which had been selected both as Top KRICT laboratory and Top National R&D Project. For in-depth examination, the target lab was supposed to be observed for a long time, taking part in the lab meetings, interviewing the researchers. From the interview data, Protocol analysis or Verbal data analysis was employed to analyze the recorded data. The research results are as follows. First, as several studies had suggested, the frequent use of analogies was verified as an important source for scientists' creative thoughts, in that those analogies were used for 12 times in 2 lab meetings, which was 6 times per each. Secondly, the frequent appearance of unexpected findings was found, that is, 8 out of 15 experiment findings were unexpected. We found that the scientists pay close attention to the unexpected findings in that 67 out of 88 intra-group interactions were about the unexpected findings, and 21 out of 24 individual reasoningblocks were about the unexpected findings. Finally, we found that the seeds of new knowledge and ideas sprouted and spread through the distributed reasoning process, which is the major characteristic of modern science that is generally conducted by group of scientists. The findings have two theoretical implications. First, it may increase the availability of Ikujiro Nonaka's knowledge-creation model by adding another case study. It may also contribute to balance between supply-side and demand-side perspective of Innovation. System studies by supplementing supply-side perspective

    Analysis of Human Accelerated DNA Regions Using Archaic Hominin Genomes

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    Several previous comparisons of the human genome with other primate and vertebrate genomes identified genomic regions that are highly conserved in vertebrate evolution but fast-evolving on the human lineage. These human accelerated regions (HARs) may be regions of past adaptive evolution in humans. Alternatively, they may be the result of non-adaptive processes, such as biased gene conversion. We captured and sequenced DNA from a collection of previously published HARs using DNA from an Iberian Neandertal. Combining these new data with shotgun sequence from the Neandertal and Denisova draft genomes, we determine at least one archaic hominin allele for 84% of all positions within HARs. We find that 8% of HAR substitutions are not observed in the archaic hominins and are thus recent in the sense that the derived allele had not come to fixation in the common ancestor of modern humans and archaic hominins. Further, we find that recent substitutions in HARs tend to have come to fixation faster than substitutions elsewhere in the genome and that substitutions in HARs tend to cluster in time, consistent with an episodic rather than a clock-like process underlying HAR evolution. Our catalog of sequence changes in HARs will help prioritize them for functional studies of genomic elements potentially responsible for modern human adaptations

    DPRESS: Localizing estimates of predictive uncertainty

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    <p>Abstract</p> <p>Background</p> <p>The need to have a quantitative estimate of the uncertainty of prediction for QSAR models is steadily increasing, in part because such predictions are being widely distributed as tabulated values disconnected from the models used to generate them. Classical statistical theory assumes that the error in the population being modeled is independent and identically distributed (IID), but this is often not actually the case. Such inhomogeneous error (heteroskedasticity) can be addressed by providing an individualized estimate of predictive uncertainty for each particular new object <it>u</it>: the standard error of prediction <it>s</it><sub>u </sub>can be estimated as the non-cross-validated error <it>s</it><sub>t* </sub>for the closest object <it>t</it>* in the training set adjusted for its separation <it>d </it>from <it>u </it>in the descriptor space relative to the size of the training set.</p> <p><display-formula><graphic file="1758-2946-1-11-i1.gif"/></display-formula></p> <p>The predictive uncertainty factor <it>γ</it><sub>t* </sub>is obtained by distributing the internal predictive error sum of squares across objects in the training set based on the distances between them, hence the acronym: <it>D</it>istributed <it>PR</it>edictive <it>E</it>rror <it>S</it>um of <it>S</it>quares (DPRESS). Note that <it>s</it><sub>t* </sub>and <it>γ</it><sub>t*</sub>are characteristic of each training set compound contributing to the model of interest.</p> <p>Results</p> <p>The method was applied to partial least-squares models built using 2D (molecular hologram) or 3D (molecular field) descriptors applied to mid-sized training sets (<it>N </it>= 75) drawn from a large (<it>N </it>= 304), well-characterized pool of cyclooxygenase inhibitors. The observed variation in predictive error for the external 229 compound test sets was compared with the uncertainty estimates from DPRESS. Good qualitative and quantitative agreement was seen between the distributions of predictive error observed and those predicted using DPRESS. Inclusion of the distance-dependent term was essential to getting good agreement between the estimated uncertainties and the observed distributions of predictive error. The uncertainty estimates derived by DPRESS were conservative even when the training set was biased, but not excessively so.</p> <p>Conclusion</p> <p>DPRESS is a straightforward and powerful way to reliably estimate individual predictive uncertainties for compounds outside the training set based on their distance to the training set and the internal predictive uncertainty associated with its nearest neighbor in that set. It represents a sample-based, <it>a posteriori </it>approach to defining applicability domains in terms of localized uncertainty.</p
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