WorldWideScience

Sample records for buffed energy landscapes

  1. Research using energy landscape

    International Nuclear Information System (INIS)

    Kim, Hack Jin

    2007-01-01

    Energy landscape is a theoretical tool used for the study of systems where cooperative processes occur such as liquid, glass, clusters, and protein. Theoretical and experimental researches related to energy landscape are introduced in this review

  2. COMPOSITES FROM LEATHER INDUSTRY BUFFING DUST: A REVIEW

    Directory of Open Access Journals (Sweden)

    KILIÇ Eylem

    2017-05-01

    Full Text Available Leather buffing dust is a fine powder of collagen fibril waste from milling and buffing operations and constitutes an important part of solid wastes generated from chrome tanned leather production processes. It is one of the difficult tannery wastes to manage and current practice of its disposal includes its incineration and disposal in landfill. The scientific literature reports numerous studies on its utilization in composites formulations. Chrome tanned buffing dust has been used as filler for various polymeric matrices with the aim of producing leather-like composites for potential applications such as hand bags, wallets, key chain holder and purses and footwear products such as shoe soles, insole, heels etc. This paper compiles different research works done by researchers regarding composites made from leather industry buffing dust. The characteristics of composites are also presented by making use of previously published studies carried out with different polymer matrices. Reviewed studies reveal that fiber-reinforced composites utilizing buffing dust provide landfill avoidance, energy conservation, decrease depletion of virgin raw material, enable production of low cost composites with improved mechanical properties that can be used for multifunctional applications and moreover they provide solution to the environmental problems associated with the waste management of the leather industry.

  3. Exploring Energy Landscapes

    Science.gov (United States)

    Wales, David J.

    2018-04-01

    Recent advances in the potential energy landscapes approach are highlighted, including both theoretical and computational contributions. Treating the high dimensionality of molecular and condensed matter systems of contemporary interest is important for understanding how emergent properties are encoded in the landscape and for calculating these properties while faithfully representing barriers between different morphologies. The pathways characterized in full dimensionality, which are used to construct kinetic transition networks, may prove useful in guiding such calculations. The energy landscape perspective has also produced new procedures for structure prediction and analysis of thermodynamic properties. Basin-hopping global optimization, with alternative acceptance criteria and generalizations to multiple metric spaces, has been used to treat systems ranging from biomolecules to nanoalloy clusters and condensed matter. This review also illustrates how all this methodology, developed in the context of chemical physics, can be transferred to landscapes defined by cost functions associated with machine learning.

  4. Energy landscape Allgaeu; Energielandschaft Allgaeu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-04-01

    In tandems with questions on the energy policy turnaround, the topics cultural landscape history, morphology, actual land use, tourism, settlement development or infrastructure are summarized in regional concepts and designs to a consistent landscape. Thus, a true integration of renewable energies in the landscape enhances existing or creates completely new landscape qualities. Energy supply shall be understood as a component of the every day life world. The energy supply shall not be hidden any more, but it rather should be communicated as the brand 'Allgaeu'.

  5. Energy landscapes in a crowded world

    NARCIS (Netherlands)

    Pasqualetti, Martin; Stremke, Sven

    2018-01-01

    One of the main drivers of landscape transformation has been our demand for energy. We refer to the results of such transformations as "energy landscapes". This paper examines the definition of energy landscapes within a conceptual framework, proposes a classification of energy landscapes, and

  6. Energy Landscape of Social Balance

    Science.gov (United States)

    Marvel, Seth A.; Strogatz, Steven H.; Kleinberg, Jon M.

    2009-11-01

    We model a close-knit community of friends and enemies as a fully connected network with positive and negative signs on its edges. Theories from social psychology suggest that certain sign patterns are more stable than others. This notion of social “balance” allows us to define an energy landscape for such networks. Its structure is complex: numerical experiments reveal a landscape dimpled with local minima of widely varying energy levels. We derive rigorous bounds on the energies of these local minima and prove that they have a modular structure that can be used to classify them.

  7. Energy landscape of social balance.

    Science.gov (United States)

    Marvel, Seth A; Strogatz, Steven H; Kleinberg, Jon M

    2009-11-06

    We model a close-knit community of friends and enemies as a fully connected network with positive and negative signs on its edges. Theories from social psychology suggest that certain sign patterns are more stable than others. This notion of social "balance" allows us to define an energy landscape for such networks. Its structure is complex: numerical experiments reveal a landscape dimpled with local minima of widely varying energy levels. We derive rigorous bounds on the energies of these local minima and prove that they have a modular structure that can be used to classify them.

  8. Energy transition: towards landscape devastation?

    International Nuclear Information System (INIS)

    Posokhow, Andre

    2013-09-01

    The author criticizes some aspects of the content of the French policy for energy transition. He states that the objective of reduction of greenhouse emissions is unreachable and moreover useless when China keeps on opening new coal-fired power stations. He states that temperatures do not increase any longer and that it is not sure that CO 2 emissions are responsible for past increases. He outlines that the power of wind turbines is only a quarter of their theoretical one, that replacing nuclear energy by wind energy would require the installation of 33.000 wind turbines. He states that objectives of energy saving are not credible, and that the energy mix predictions are fuzzy. He outlines contradictions about the nuclear power station life duration, states that the installation of 210 wind turbines per district would devastate the French landscape

  9. Competing Wind Energy Discourses, Contested Landscapes

    Directory of Open Access Journals (Sweden)

    Antje Otto

    2014-10-01

    Full Text Available The impairment of landscapes is a concern constantly raised against wind energy developments in Germany as in other countries. Often, landscapes or landscape types are treated in the literature as essentialist or at least as uncontested categories. We analyse two examples of local controversies about wind energy, in which “landscape” is employed by supporters and opponents alike, from a poststructuralist and discourse theoretical angle. The aim is to identify and compare landscape constructs produced in the micro discourses of wind energy objectors and proponents at local level (a within each case, (b between the two cases and (c with landscape constructs that were previously found in macro discourses. One major finding is that several different landscapes can exist at one and the same place. Furthermore there seems to be a relatively stable set of competing landscape concepts which is reproduced in specific controversies. The paper concludes by highlighting practical consequences and by identifying promising avenues of further research.

  10. Sustainable energy landscapes : designing, planning, and development

    NARCIS (Netherlands)

    Stremke, S.; Dobbelsteen, van den A.

    2013-01-01

    In the near future the appearance and spatial organization of urban and rural landscapes will be strongly influenced by the generation of renewable energy. One of the critical tasks will be the re-integration of these sustainable energy landscapes into the existing environment—which people value and

  11. Energy forest cultivation and the landscape

    International Nuclear Information System (INIS)

    Bell, Simon

    1994-01-01

    The place of energy forestry in the landscape is discussed, principally with reference to Britain and Europe. The importance of design as a means of ensuring an attractive appearance, while meeting functional and economic requirements, is stressed. Simple design principles which help energy forests, mainly short rotation arable coppice, to fit into the landscape are suggested. (author)

  12. Energy landscapes, landscapes in transition. How to prepare one's territory to the deployment of renewable energies

    International Nuclear Information System (INIS)

    2014-06-01

    This guide first defines the notion of landscape, outlines what is at stake with decentralised renewable energy production, and presents the various important aspects of a deployment of decentralised renewable energy production. It describes how to define a general strategy for the integration of this production: relationship between energy and landscape, project implementation, partnership, tools to anticipate changes, evolution of social demand through dialogue, conciliation of technical and financial constraints and landscape ambitions. An appendix proposes legal and bibliographical information: legal relationships between energy and landscape, possible arrangements for PLU (plan local d'urbanisme, local urban plan) and SCOT (schema de coherence territoriale, territorial planning document)

  13. Energy landscapes shape animal movement ecology.

    Science.gov (United States)

    Shepard, Emily L C; Wilson, Rory P; Rees, W Gareth; Grundy, Edward; Lambertucci, Sergio A; Vosper, Simon B

    2013-09-01

    The metabolic costs of animal movement have been studied extensively under laboratory conditions, although frequently these are a poor approximation of the costs of operating in the natural, heterogeneous environment. Construction of "energy landscapes," which relate animal locality to the cost of transport, can clarify whether, to what extent, and how movement properties are attributable to environmental heterogeneity. Although behavioral responses to aspects of the energy landscape are well documented in some fields (notably, the selection of tailwinds by aerial migrants) and scales (typically large), the principles of the energy landscape extend across habitat types and spatial scales. We provide a brief synthesis of the mechanisms by which environmentally driven changes in the cost of transport can modulate the behavioral ecology of animal movement in different media, develop example cost functions for movement in heterogeneous environments, present methods for visualizing these energy landscapes, and derive specific predictions of expected outcomes from individual- to population- and species-level processes. Animals modulate a suite of movement parameters (e.g., route, speed, timing of movement, and tortuosity) in relation to the energy landscape, with the nature of their response being related to the energy savings available. Overall, variation in movement costs influences the quality of habitat patches and causes nonrandom movement of individuals between them. This can provide spatial and/or temporal structure to a range of population- and species-level processes, ultimately including gene flow. Advances in animal-attached technology and geographic information systems are opening up new avenues for measuring and mapping energy landscapes that are likely to provide new insight into their influence in animal ecology.

  14. The renewable energies: the landscape

    International Nuclear Information System (INIS)

    Acket, C.; Bacher, P.

    2005-03-01

    If one takes into account the hydroelectric power, the France is the first european country in the renewable energies domain. The position is also honorable concerning the wood energy. Meanwhile, for the solar and wind energy, France is late. To discuss this debate, the authors bring together today data on the renewable energies, offer some proposals for the next 50 years taking into account the reduction of greenhouse gases emission for 2050. (A.L.B.)

  15. Towards an Integrated Energy Landscape

    NARCIS (Netherlands)

    de Boer, Jessica; Zuidema, Christian

    2013-01-01

    In this paper, we show that an area-based approach to fostering the ‘energy transition’ has potential to help spatial planners and policy makers understand how innovative sustainable energy initiatives may contribute to the energy transition. On the basis of a desk study of research reports on

  16. Orientational dynamics and energy landscape features of ...

    Indian Academy of Sciences (India)

    WINTEC

    Energy landscape analysis of inherent structures shows that the ... to be strikingly similar to that of supercooled molecular liquids5 .... where eiα is the α-component (in the space-fixed frame) of the unit orientation vector ei along the principal symmetry axis of the ith ellipsoid of revo- ..... understand pathways of protein folding.

  17. Exploring the conformational energy landscape of proteins

    Energy Technology Data Exchange (ETDEWEB)

    Nienhaus, G.U. [Univ. of Illinois, Urbana, IL (United States)]|[Universitaet Ulm (Germany); Mueller, J.D.; McMahon, B.H. [Univ. of Illinois, Urbana, IL (United States)] [and others

    1997-04-01

    Proteins possess a complex energy landscape with a large number of local minima called conformational substates that are arranged in a hierarchical fashion. Here we discuss experiments aimed at the elucidation of the energy landscape in carbonmonoxy myoglobin (MbCO). In the highest tier of the hierarchy, a few taxonomic substates exist. Because of their small number, these substates are accessible to detailed structural investigations. Spectroscopic experiments are discussed that elucidate the role of protonations of amino acid side chains in creating the substates. The lower tiers of the hierarchy contain a large number of statistical substates. Substate interconversions are observed in the entire temperature range from below 1 K up to the denaturation temperature, indicating a wide spectrum of energy barriers that separate the substates.

  18. The changing geopolitical landscape of energy

    International Nuclear Information System (INIS)

    Lesourne, Jacques

    2011-08-01

    The author first discusses the impact of the financial crisis of 2008, and of the large-scale exploitation of shale gases in the USA on energy policies and on the geopolitical landscape of energy. Then, he discusses the influence that events which occurred in 2011 had on these issues: firstly, the Copenhagen and Cancun Conferences, secondly, the Fukushima accident, thirdly, the nuclear phasing-out by Germany and incidentally by Italy, and fourthly, the Arab Spring. In the next parts, he comments the consequences for the European energy policy, and the perspectives for the struggle against climate change

  19. Energy-landscape Nexus: Advancing a conceptual framework for the design of sustainable energy landscapes

    NARCIS (Netherlands)

    Stremke, S.

    2013-01-01

    For some time now, the concept of “energy landscape” is discussed in academia while more and more practising landscape architects contribute to the siting, designing, and assessment of renewable energy technologies (see Stremke et al. 2012). Yet, there remains some ambiguity what exactly is meant

  20. New interaction paths in the energy landscape: the role of local energy initiatives

    OpenAIRE

    de Boer, Jessica; Zuidema, Christian; Gugerell, Katharina

    2018-01-01

    Energy transition is an encompassing process which not only involves the energy system but also the landscape in which the energy system is embedded. Renewable energy is triggering new interactions with local landscapes in physical, socio-economic and institutional senses. We capture these interactions using the energy landscape concept, which expresses the interdependence of the energy system with the landscape. We aim to understand whether and how local energy initiatives facilitate this in...

  1. Potential energy landscapes of elemental and heterogeneous chalcogen clusters

    International Nuclear Information System (INIS)

    Mauro, John C.; Loucks, Roger J.; Balakrishnan, Jitendra; Varshneya, Arun K.

    2006-01-01

    We describe the potential energy landscapes of elemental S 8 , Se 8 , and Te 8 clusters using disconnectivity graphs. Inherent structures include both ring and chain configurations, with rings especially dominant in Se 8 . We also map the potential energy landscapes of heterogeneous Se n (S,Te) 8-n clusters, which offer insights into the structure of heterogeneous chalcogen glasses

  2. Mitigation/Adaptation: landscape architecture meets sustainable energy transition

    NARCIS (Netherlands)

    Stremke, S.

    2009-01-01

    Mitigation of climate change and adaptation to renewable energy sources are among the emerging fields of activity in landscape architecture. If landscape architects recognize the need for sustainable development on the basis of renewable energy sources, then how can we contribute to sustainable and

  3. Energy landscapes in proteins and glasses

    Science.gov (United States)

    Singh, Sadanand

    Soft materials are ubiquitous in our day-to-day life. They include liquids, colloids, polymers, foams, gels, granular systems, and a number of biological materials. While these materials exhibit a wide range of textures and morphologies, many of their properties have common physicochemical origins. A better understanding of such origins would lead to rational design and engineering of functional soft materials. A common feature of soft materials is the wide range of time and length scales that characterizes their behavior. Unfortunately, available molecular modeling techniques are often ill-suited for problems that exhibit multiple length and time scales. In this thesis, we introduce and implement new simulation methods that have enabled molecular-level studies of soft materials. Such methods permit calculation of free energy surfaces, and we demonstrate their usefulness in the context of proteins and glasses, both of which exhibit rugged free energy landscapes. A first application is concerned with human amylin, a protein associated with Type II diabetes. Patients with Type II diabetes exhibit fibrillar deposits of human amylin protein in the pancreas. By applying the advanced simulation methods and algorithms developed in this work, we investigate the structure and folding dynamics of human amylin. A detailed mechanism is presented at the atomic-level for the nucleation and aggregation of the peptide. The results presented in this work could help in development of therapeutic strategies for Type II diabetes. The second application is concerned with the study of vapor-deposited ultrastable glasses. These stable glasses have, far below the conventional glass transition temperature, the properties expected from the equilibrium supercooled liquid state. Our results indicate that optimal stability is attained when deposition occurs near the Kauzmann temperature. We also show that the extraordinary stability of model vapor deposited glasses is associated with distinct

  4. Breakthrough Adsorption Study of Crude Oil Removal Using Buffing Dust

    Science.gov (United States)

    Setyaningsih, L. W. N.; Yuliansyah, A. T.; Prasetyo, A.; Arimanintan, S. K.; Putri, D. R.

    2018-05-01

    The utilization of leather industry solid waste as adsorbent to separate oil from water emulsions of surfactant flooding process is a solution that is relatively inexpensive. This study was conducted aiming to obtain a mathematical model that is appropriate for the adsorption process of crude oil by buffing dust in emulsion phase with a continuous adsorption method. Variations in the column adsorption experiments were carried out, such as: flow rate of feed of water-crude oil-surfactant, the concentration of crude oil in the feed, and mass of adsorbent used. Data were evaluated using three models: Adams Bohart, Thomas and Yan. Best results are obtained on the following conditions, the feed flow rate of 60 mL/minute, the crude oil concentration in feed is 1.5% volume and the mass of adsorbent used was 10 g. The values of kinetic constant and adsorption capacity obtained from Yan Model was 21.7774 mL/mg/minute and 220.9581 mg/g with the relative error obtained is 5.4424%.

  5. How animals distribute themselves in space: variable energy landscapes

    OpenAIRE

    Masello, Juan F.; Kato, Akiko; Sommerfeld, Julia; Mattern, Thomas; Quillfeldt, Petra

    2017-01-01

    Background Foraging efficiency determines whether animals will be able to raise healthy broods, maintain their own condition, avoid predators and ultimately increase their fitness. Using accelerometers and GPS loggers, features of the habitat and the way animals deal with variable conditions can be translated into energetic costs of movement, which, in turn, can be translated to energy landscapes.We investigated energy landscapes in Gentoo Penguins Pygoscelis papua from two colonies at New Is...

  6. Ideal glass transitions in thin films: An energy landscape perspective

    OpenAIRE

    Truskett, Thomas M.; Ganesan, Venkat

    2003-01-01

    We introduce a mean-field model for the potential energy landscape of a thin fluid film confined between parallel substrates. The model predicts how the number of accessible basins on the energy landscape and, consequently, the film's ideal glass transition temperature depend on bulk pressure, film thickness, and the strength of the fluid-fluid and fluid-substrate interactions. The predictions are in qualitative agreement with the experimental trends for the kinetic glass transition temperatu...

  7. Ideal glass transitions in thin films: An energy landscape perspective

    Science.gov (United States)

    Truskett, Thomas M.; Ganesan, Venkat

    2003-07-01

    We introduce a mean-field model for the potential energy landscape of a thin fluid film confined between parallel substrates. The model predicts how the number of accessible basins on the energy landscape and, consequently, the film's ideal glass transition temperature depend on bulk pressure, film thickness, and the strength of the fluid-fluid and fluid-substrate interactions. The predictions are in qualitative agreement with the experimental trends for the kinetic glass transition temperature of thin films, suggesting the utility of landscape-based approaches for studying the behavior of confined fluids.

  8. The effects of landscaping on the residential cooling energy

    Science.gov (United States)

    Misni, A.

    2018-02-01

    This paper examines the effectiveness of landscaping on the air-conditioning energy saving of houses in a tropical environment. This case study involved looking at the construction and landscaping of three single-family houses in three sections of Shah Alam, Selangor, Malaysia. The houses ranged in age from 5 to 30 years old, which provided different examples of construction and maturity levels of the surrounding landscaping. Landscaping affects the thermal performance as well as on the air-conditioning energy of houses, in how it provides shade, channels wind, and evapotranspiration. While the construction of the three houses was similar, they were different in size and design, including their landscape design. These houses were chosen because they are representative of single-family tropical houses and landscaping styles in Malaysia since 30 years ago. Three houses were chosen; the 30-year-old house, the 10-year-old house, and the 5-year-old house. In a tropical country, landscaping is used to reduce the effects of the hot and humid climate. The houses spent 15-45% of the electricity cost on cooling. These results were influenced by human factors and the surrounding landscaping. Every type of vegetation, such as trees, grass, shrubs, groundcover, and turf, contributes to reducing air temperatures near the house and providing evaporative cooling.

  9. Random versus Deterministic Descent in RNA Energy Landscape Analysis

    Directory of Open Access Journals (Sweden)

    Luke Day

    2016-01-01

    Full Text Available Identifying sets of metastable conformations is a major research topic in RNA energy landscape analysis, and recently several methods have been proposed for finding local minima in landscapes spawned by RNA secondary structures. An important and time-critical component of such methods is steepest, or gradient, descent in attraction basins of local minima. We analyse the speed-up achievable by randomised descent in attraction basins in the context of large sample sets where the size has an order of magnitude in the region of ~106. While the gain for each individual sample might be marginal, the overall run-time improvement can be significant. Moreover, for the two nongradient methods we analysed for partial energy landscapes induced by ten different RNA sequences, we obtained that the number of observed local minima is on average larger by 7.3% and 3.5%, respectively. The run-time improvement is approximately 16.6% and 6.8% on average over the ten partial energy landscapes. For the large sample size we selected for descent procedures, the coverage of local minima is very high up to energy values of the region where the samples were randomly selected from the partial energy landscapes; that is, the difference to the total set of local minima is mainly due to the upper area of the energy landscapes.

  10. Preliminary study on immobilization of buffing dust by solidification method in ceramic brick

    Science.gov (United States)

    Yuliansyah, Ahmad Tawfiequrrahman; Prasetya, Agus; Putra, Arif Eka; Satriawan, Humam Budi

    2017-11-01

    Leather-based industries generate a substantial amount of hazardous solid and liquid wastes in their process. One of the solid wastes is buffing dust, which is fine particulates containing fat, tanning, dyes and chromium. From 1 ton of leather processed, approximately 2-6 kg of buffing dust is generated. Chromium in the buffing dust is carcinogenic, so a proper handling is highly required. Solidification is a method commonly used to immobilize toxic material. Hence, the material is trapped in a matrix made of binding agents to minimize its mobility. However, a very small amount of the materials is sometimes released to the environment during storage. This study investigates leaching process of chromium from immobilized buffing dust in ceramic brick. Buffing dust, which contains chromium, is solidified by mixing it with clay at certain compositions and fired in a muffle furnace to produce a ceramic brick. Performance of the solidification process is evaluated by measuring the leaching of chromium in the leaching test. The results show that the solidification has significantly reduced the potential release of chromium to the environment. Higher of the firing temperature, less chromium is leached from ceramic brick. The chromium concentration of leachate water from 800°C brick is 0.376 ppm, while those from 850 and 900°C brick are 0.212 and 0.179 ppm respectively.

  11. Potential energy landscape of TIP4P/2005 water

    Science.gov (United States)

    Handle, Philip H.; Sciortino, Francesco

    2018-04-01

    We report a numerical study of the statistical properties of the potential energy landscape of TIP4P/2005, one of the most accurate rigid water models. We show that, in the region where equilibrated configurations can be generated, a Gaussian landscape description is able to properly describe the model properties. We also find that the volume dependence of the landscape properties is consistent with the existence of a locus of density maxima in the phase diagram. The landscape-based equation of state accurately reproduces the TIP4P/2005 pressure-vs-volume curves, providing a sound extrapolation of the free-energy at low T. A positive-pressure liquid-liquid critical point is predicted by the resulting free-energy.

  12. New interaction paths in the energy landscape: the role of local energy initiatives

    NARCIS (Netherlands)

    de Boer, Jessica; Zuidema, Christian; Gugerell, Katharina

    2018-01-01

    Energy transition is an encompassing process which not only involves the energy system but also the landscape in which the energy system is embedded. Renewable energy is triggering new interactions with local landscapes in physical, socio-economic and institutional senses. We capture these

  13. Energy landscapes for a machine learning application to series data

    Energy Technology Data Exchange (ETDEWEB)

    Ballard, Andrew J.; Stevenson, Jacob D.; Das, Ritankar; Wales, David J., E-mail: dw34@cam.ac.uk [University Chemical Laboratories, Lensfield Road, Cambridge CB2 1EW (United Kingdom)

    2016-03-28

    Methods developed to explore and characterise potential energy landscapes are applied to the corresponding landscapes obtained from optimisation of a cost function in machine learning. We consider neural network predictions for the outcome of local geometry optimisation in a triatomic cluster, where four distinct local minima exist. The accuracy of the predictions is compared for fits using data from single and multiple points in the series of atomic configurations resulting from local geometry optimisation and for alternative neural networks. The machine learning solution landscapes are visualised using disconnectivity graphs, and signatures in the effective heat capacity are analysed in terms of distributions of local minima and their properties.

  14. Energy landscapes for a machine learning application to series data

    International Nuclear Information System (INIS)

    Ballard, Andrew J.; Stevenson, Jacob D.; Das, Ritankar; Wales, David J.

    2016-01-01

    Methods developed to explore and characterise potential energy landscapes are applied to the corresponding landscapes obtained from optimisation of a cost function in machine learning. We consider neural network predictions for the outcome of local geometry optimisation in a triatomic cluster, where four distinct local minima exist. The accuracy of the predictions is compared for fits using data from single and multiple points in the series of atomic configurations resulting from local geometry optimisation and for alternative neural networks. The machine learning solution landscapes are visualised using disconnectivity graphs, and signatures in the effective heat capacity are analysed in terms of distributions of local minima and their properties.

  15. Inflation in random landscapes with two energy scales

    Science.gov (United States)

    Blanco-Pillado, Jose J.; Vilenkin, Alexander; Yamada, Masaki

    2018-02-01

    We investigate inflation in a multi-dimensional landscape with a hierarchy of energy scales, motivated by the string theory, where the energy scale of Kahler moduli is usually assumed to be much lower than that of complex structure moduli and dilaton field. We argue that in such a landscape, the dynamics of slow-roll inflation is governed by the low-energy potential, while the initial condition for inflation are determined by tunneling through high-energy barriers. We then use the scale factor cutoff measure to calculate the probability distribution for the number of inflationary e-folds and the amplitude of density fluctuations Q, assuming that the low-energy landscape is described by a random Gaussian potential with a correlation length much smaller than M pl. We find that the distribution for Q has a unique shape and a preferred domain, which depends on the parameters of the low-energy landscape. We discuss some observational implications of this distribution and the constraints it imposes on the landscape parameters.

  16. Buffing dust as a filler of carboxylated butadiene-acrylonitrile rubber and butadiene-acrylonitrile rubber.

    Science.gov (United States)

    Chronska, K; Przepiorkowska, A

    2008-03-01

    Buffing dust from chrome tanned leather is one of the difficult tannery wastes to manage. It is also hazardous to both human health and the environment. The scientific literature rarely reports studies on dust management, especially on its utilization as a filler for elastomers. In this connection we have made an attempt to use this leather waste as a filler for rubbers such as XNBR and NBR. The addition of the buffing dust to rubber mixes brought improvement in mechanical properties, and increase in resistance to thermal ageing as well as in electric conductivity and crosslink density of vulcalizates.

  17. Integrated visions (part II): Envisioning Sustainable Energy Landscapes

    NARCIS (Netherlands)

    Stremke, S.; Koh, J.; Neven, C.T.; Boekel, A.

    2012-01-01

    ABSTRACT Climate change and resource depletion are driving the transition to renewable energy sources. Both the supply of renewables and the demand for energy are influenced by the physical environment and therefore concern spatial planning and landscape design. Envisioning the longterm development

  18. Inflation, Dark Matter, and Dark Energy in the String Landscape

    OpenAIRE

    Liddle, Andrew R; Ureña-López, L Arturo

    2006-01-01

    We consider the conditions needed to unify the description of dark matter, dark energy and inflation in the context of the string landscape. We find that incomplete decay of the inflaton field gives the possibility that a single field is responsible for all three phenomena. By contrast, unifying dark matter and dark energy into a single field, separate from the inflaton, appears rather difficult.

  19. Energy Landscapes for the Self-Assembly of Supramolecular Polyhedra

    Science.gov (United States)

    Russell, Emily R.; Menon, Govind

    2016-06-01

    We develop a mathematical model for the energy landscape of polyhedral supramolecular cages recently synthesized by self-assembly (Sun et al. in Science 328:1144-1147, 2010). Our model includes two essential features of the experiment: (1) geometry of the organic ligands and metallic ions; and (2) combinatorics. The molecular geometry is used to introduce an energy that favors square-planar vertices (modeling {Pd}^{2+} ions) and bent edges with one of two preferred opening angles (modeling boomerang-shaped ligands of two types). The combinatorics of the model involve two-colorings of edges of polyhedra with four-valent vertices. The set of such two-colorings, quotiented by the octahedral symmetry group, has a natural graph structure and is called the combinatorial configuration space. The energy landscape of our model is the energy of each state in the combinatorial configuration space. The challenge in the computation of the energy landscape is a combinatorial explosion in the number of two-colorings of edges. We describe sampling methods based on the symmetries of the configurations and connectivity of the configuration graph. When the two preferred opening angles encompass the geometrically ideal angle, the energy landscape exhibits a very low-energy minimum for the most symmetric configuration at equal mixing of the two angles, even when the average opening angle does not match the ideal angle.

  20. Learning free energy landscapes using artificial neural networks.

    Science.gov (United States)

    Sidky, Hythem; Whitmer, Jonathan K

    2018-03-14

    Existing adaptive bias techniques, which seek to estimate free energies and physical properties from molecular simulations, are limited by their reliance on fixed kernels or basis sets which hinder their ability to efficiently conform to varied free energy landscapes. Further, user-specified parameters are in general non-intuitive yet significantly affect the convergence rate and accuracy of the free energy estimate. Here we propose a novel method, wherein artificial neural networks (ANNs) are used to develop an adaptive biasing potential which learns free energy landscapes. We demonstrate that this method is capable of rapidly adapting to complex free energy landscapes and is not prone to boundary or oscillation problems. The method is made robust to hyperparameters and overfitting through Bayesian regularization which penalizes network weights and auto-regulates the number of effective parameters in the network. ANN sampling represents a promising innovative approach which can resolve complex free energy landscapes in less time than conventional approaches while requiring minimal user input.

  1. Learning free energy landscapes using artificial neural networks

    Science.gov (United States)

    Sidky, Hythem; Whitmer, Jonathan K.

    2018-03-01

    Existing adaptive bias techniques, which seek to estimate free energies and physical properties from molecular simulations, are limited by their reliance on fixed kernels or basis sets which hinder their ability to efficiently conform to varied free energy landscapes. Further, user-specified parameters are in general non-intuitive yet significantly affect the convergence rate and accuracy of the free energy estimate. Here we propose a novel method, wherein artificial neural networks (ANNs) are used to develop an adaptive biasing potential which learns free energy landscapes. We demonstrate that this method is capable of rapidly adapting to complex free energy landscapes and is not prone to boundary or oscillation problems. The method is made robust to hyperparameters and overfitting through Bayesian regularization which penalizes network weights and auto-regulates the number of effective parameters in the network. ANN sampling represents a promising innovative approach which can resolve complex free energy landscapes in less time than conventional approaches while requiring minimal user input.

  2. The German energy landscape in 2015

    International Nuclear Information System (INIS)

    Lauer, Hartmut

    2016-01-01

    This article proposes a brief overview of the German energy sector: stagnation of primary energy consumption, shares of the different energy sources (renewable, coal, lignite, oil, gas, nuclear), shares of the different electric power production sources and their recent evolution. It evokes issues related to the objectives defined for energy transition, the high level of renewable energy production and the high level of power exports. It outlines that consumption must be reduced to reach the objectives defined for 2020. It notices a stagnation of the energy system de-carbonation, and comments the evolution of electricity prices

  3. AIRBORNE ASBESTOS CONCENTRATIONS DURING BUFFING, BURNISHING, AND STRIPPING OF RESILIENT FLOOR TILE

    Science.gov (United States)

    The study was conducted to evaluate airborne asbestos concentrations during low-speed spray-buffing, ultra high-speed burnishing, and wet-stripping of asbestos-containing resilient floor tile under pre-existing and prepared levels of floor care maintenance. Low-speed spray-buffin...

  4. Sustainable energy landscapes: The power of imagination

    NARCIS (Netherlands)

    Stremke, S.

    2012-01-01

    Resource depletion and climate change motivate a transition to sustainable energy systems that make effective use of renewable sources. Sustainable energy transition necessitates a transformation of large parts of the existing built environment and presents one of the great challenges of present-day

  5. Membranes: A Variety of Energy Landscapes for Many Transfer Opportunities.

    Science.gov (United States)

    Bacchin, Patrice

    2018-02-22

    A membrane can be represented by an energy landscape that solutes or colloids must cross. A model accounting for the momentum and the mass balances in the membrane energy landscape establishes a new way of writing for the Darcy law. The counter-pressure in the Darcy law is no longer written as the result of an osmotic pressure difference but rather as a function of colloid-membrane interactions. The ability of the model to describe the physics of the filtration is discussed in detail. This model is solved in a simplified energy landscape to derive analytical relationships that describe the selectivity and the counter-pressure from ab initio operating conditions. The model shows that the stiffness of the energy landscape has an impact on the process efficiency: a gradual increase in interactions (such as with hourglass pore shape) can reduce the separation energetic cost. It allows the introduction of a new paradigm to increase membrane efficiency: the accumulation that is inherent to the separation must be distributed across the membrane. Asymmetric interactions thus lead to direction-dependent transfer properties and the membrane exhibits diode behavior. These new transfer opportunities are discussed.

  6. Evaluating the landscape impact of renewable energy plants

    Science.gov (United States)

    Ioannidis, Romanos; Koutsoyiannis, Demetris

    2017-04-01

    Different types of renewable energy have been on an ongoing competition with each other. There has been a lot of research comparing the most common types of renewable energy plants in relation with their efficiency, cost and environmental impact. However, few papers so far have attempted to analyse their impact on landscape and there has never been in depth research on which type of renewable energy causes the least impact on the natural, cultural and aesthetic characteristics of a landscape. This seems to be a significant omission given the vast areas of land already covered with renewable energy plants and the worldwide plans for many more renewable energy projects in the future. Meanwhile, the low aesthetic quality of renewable energy plants has already been an obstacle to their further development, with several relevant examples from countries such as Spain and the Netherlands. There have even been cases where aesthetic degradation is the primary or even the single argument of the opposition to proposed plants. In any case, the aesthetic design and the integration of renewable energy plants into the landscape should really be important design parameters if we plan those projects to truly be sustainable and to be considered complete works of engineering. To initiate dialogue over those aspects of renewable energy, we provide a first comparison on hydro, solar and wind energy. To materialize this comparison, we use data from existing dams, photovoltaic and wind farms. Initially, the average area per MW covered by each type of energy plant is calculated and then evaluated qualitatively from a landscape-impact perspective. Although the area affected is comparable in these three cases, the analysis of the data suggests that dams offer a considerable amount of advantages compared to the other two types of plants. This conclusion arises from the fact that dams, whose basic impact to the landscape is the creation of an artificial lake, contribute much less to the

  7. Peptide Free Energy Landscapes Calibrated by Molecular Orbital Calculations

    OpenAIRE

    Ono, S.; Kuroda, M.; Higo, J.; Kamiya, N.; Nakajima, N.; Nakamura, H.

    2002-01-01

    Free energy landscapes of peptide conformations werecalibrated by ab initiomolecular orbital calculations, after enhancedconformational sampling using the multicanonical molecular dynamicssimulations. Three different potentials of mean force for an isolateddipeptide were individually obtained using the conventional force fields,AMBER parm94, AMBER parm96, and CHARMm22. Each potential ofmean force was calibrated based on the umbrella sampling algorithm fromthe adiabatic energy map that was cal...

  8. Free-energy landscape of a hyperstable RNA tetraloop.

    Science.gov (United States)

    Miner, Jacob C; Chen, Alan A; García, Angel E

    2016-06-14

    We report the characterization of the energy landscape and the folding/unfolding thermodynamics of a hyperstable RNA tetraloop obtained through high-performance molecular dynamics simulations at microsecond timescales. Sampling of the configurational landscape is conducted using temperature replica exchange molecular dynamics over three isochores at high, ambient, and negative pressures to determine the thermodynamic stability and the free-energy landscape of the tetraloop. The simulations reveal reversible folding/unfolding transitions of the tetraloop into the canonical A-RNA conformation and the presence of two alternative configurations, including a left-handed Z-RNA conformation and a compact purine Triplet. Increasing hydrostatic pressure shows a stabilizing effect on the A-RNA conformation and a destabilization of the left-handed Z-RNA. Our results provide a comprehensive description of the folded free-energy landscape of a hyperstable RNA tetraloop and highlight the significant advances of all-atom molecular dynamics in describing the unbiased folding of a simple RNA secondary structure motif.

  9. Physics landscape-fixed target energies

    International Nuclear Information System (INIS)

    Berger, E.L.

    1989-10-01

    An introductory review is presented of physics issues and opportunities at Fermilab fixed-target energies. Included are discussions of precision electroweak studies; deep inelastic lepton scattering; heavy quark production, spectroscopy, and decays; perturbative QCD; prompt photon production; massive lepton production; and spin dependence. 79 refs., 7 figs

  10. Energy landscapes of resting-state brain networks

    Directory of Open Access Journals (Sweden)

    Takamitsu eWatanabe

    2014-02-01

    Full Text Available During rest, the human brain performs essential functions such as memory maintenance, which are associated with resting-state brain networks (RSNs including the default-mode network (DMN and frontoparietal network (FPN. Previous studies based on spiking-neuron network models and their reduced models, as well as those based on imaging data, suggest that resting-state network activity can be captured as attractor dynamics, i.e., dynamics of the brain state toward an attractive state and transitions between different attractors. Here, we analyze the energy landscapes of the RSNs by applying the maximum entropy model, or equivalently the Ising spin model, to human RSN data. We use the previously estimated parameter values to define the energy landscape, and the disconnectivity graph method to estimate the number of local energy minima (equivalent to attractors in attractor dynamics, the basin size, and hierarchical relationships among the different local minima. In both of the DMN and FPN, low-energy local minima tended to have large basins. A majority of the network states belonged to a basin of one of a few local minima. Therefore, a small number of local minima constituted the backbone of each RSN. In the DMN, the energy landscape consisted of two groups of low-energy local minima that are separated by a relatively high energy barrier. Within each group, the activity patterns of the local minima were similar, and different minima were connected by relatively low energy barriers. In the FPN, all dominant energy were separated by relatively low energy barriers such that they formed a single coarse-grained global minimum. Our results indicate that multistable attractor dynamics may underlie the DMN, but not the FPN, and assist memory maintenance with different memory states.

  11. RProtoBuf: Efficient Cross-Language Data Serialization in R

    Directory of Open Access Journals (Sweden)

    Dirk Eddelbuettel

    2016-07-01

    Full Text Available Modern data collection and analysis pipelines often involve a sophisticated mix of applications written in general purpose and specialized programming languages. Many formats commonly used to import and export data between different programs or systems, such as CSV or JSON, are verbose, inefficient, not type-safe, or tied to a specific programming language. Protocol Buffers are a popular method of serializing structured data between applications - while remaining independent of programming languages or operating systems. They offer a unique combination of features, performance, and maturity that seems particularly well suited for data-driven applications and numerical computing. The RProtoBuf package provides a complete interface to Protocol Buffers from the R environment for statistical computing. This paper outlines the general class of data serialization requirements for statistical computing, describes the implementation of the RProtoBuf package, and illustrates its use with example applications in large-scale data collection pipelines and web services.

  12. Comparing the Folding and Misfolding Energy Landscapes of Phosphoglycerate Kinase

    OpenAIRE

    Agocs, Gergely; Szabo, Bence T.; Koehler, Gottfried; Osvath, Szabolcs

    2012-01-01

    Partitioning of polypeptides between protein folding and amyloid formation is of outstanding pathophysiological importance. Using yeast phosphoglycerate kinase as model, here we identify the features of the energy landscape that decide the fate of the protein: folding or amyloidogenesis. Structure formation was initiated from the acid-unfolded state, and monitored by fluorescence from 10 ms to 20 days. Solvent conditions were gradually shifted between folding and amyloidogenesis, and the prop...

  13. Accelerated weight histogram method for exploring free energy landscapes

    Energy Technology Data Exchange (ETDEWEB)

    Lindahl, V.; Lidmar, J.; Hess, B. [Department of Theoretical Physics and Swedish e-Science Research Center, KTH Royal Institute of Technology, 10691 Stockholm (Sweden)

    2014-07-28

    Calculating free energies is an important and notoriously difficult task for molecular simulations. The rapid increase in computational power has made it possible to probe increasingly complex systems, yet extracting accurate free energies from these simulations remains a major challenge. Fully exploring the free energy landscape of, say, a biological macromolecule typically requires sampling large conformational changes and slow transitions. Often, the only feasible way to study such a system is to simulate it using an enhanced sampling method. The accelerated weight histogram (AWH) method is a new, efficient extended ensemble sampling technique which adaptively biases the simulation to promote exploration of the free energy landscape. The AWH method uses a probability weight histogram which allows for efficient free energy updates and results in an easy discretization procedure. A major advantage of the method is its general formulation, making it a powerful platform for developing further extensions and analyzing its relation to already existing methods. Here, we demonstrate its efficiency and general applicability by calculating the potential of mean force along a reaction coordinate for both a single dimension and multiple dimensions. We make use of a non-uniform, free energy dependent target distribution in reaction coordinate space so that computational efforts are not wasted on physically irrelevant regions. We present numerical results for molecular dynamics simulations of lithium acetate in solution and chignolin, a 10-residue long peptide that folds into a β-hairpin. We further present practical guidelines for setting up and running an AWH simulation.

  14. Polyomaviridae Assembly Polymorphism from an Energy Landscape Perspective

    Directory of Open Access Journals (Sweden)

    Karim M. ElSawy

    2008-01-01

    Full Text Available Polyomaviridae assemble in vitro into different aggregates depending on experimental conditions. We use an energy landscape approach using empirical energy calculations to quantify how the formation of these different aggregates depends on pH, the presence of bound calcium ions and disulfide linkages. Computations are carried out for SV40, a member of the Polyomaviridae family and are based on the binding free energy landscape of three distinct trimers of pentamers that correspond to the different bonding configurations between the capsid proteins observed in its crystal structure. Our computational analysis shows that the energetics of one of these environments is pivotal for the polymorphic assembly behaviour of SV40, whilst the binding energy landscapes of the other two environments are broadly funnel-shaped and thus contribute little to the formation of particles other than virus-like particles (VLP. We have quantified how the existence of bound calcium ions in the absence of disulfide linkages enhances the binding free energies of all three environments and hence, favours the assembly of VLPs. Moreover, estimation of the relative binding free energies of the three environments at pH 5 and pH 8 reveals that they are destabilized at pH 5 relative to pH 8. The extent of this destabilization is dependent on the presence of disulfide linkages and bound calcium ions and accounts for the experimentally observed polymorphic behaviour of VP1 proteins at pH 5. Interestingly, concurrent existence of bound calcium ions and disulfide linkages is found to be destabilizing and thus may disrupt the assembly of VLPs at pH 8.

  15. Characterizing structural transitions using localized free energy landscape analysis.

    Directory of Open Access Journals (Sweden)

    Nilesh K Banavali

    Full Text Available Structural changes in molecules are frequently observed during biological processes like replication, transcription and translation. These structural changes can usually be traced to specific distortions in the backbones of the macromolecules involved. Quantitative energetic characterization of such distortions can greatly advance the atomic-level understanding of the dynamic character of these biological processes.Molecular dynamics simulations combined with a variation of the Weighted Histogram Analysis Method for potential of mean force determination are applied to characterize localized structural changes for the test case of cytosine (underlined base flipping in a GTCAGCGCATGG DNA duplex. Free energy landscapes for backbone torsion and sugar pucker degrees of freedom in the DNA are used to understand their behavior in response to the base flipping perturbation. By simplifying the base flipping structural change into a two-state model, a free energy difference of upto 14 kcal/mol can be attributed to the flipped state relative to the stacked Watson-Crick base paired state. This two-state classification allows precise evaluation of the effect of base flipping on local backbone degrees of freedom.The calculated free energy landscapes of individual backbone and sugar degrees of freedom expectedly show the greatest change in the vicinity of the flipping base itself, but specific delocalized effects can be discerned upto four nucleotide positions away in both 5' and 3' directions. Free energy landscape analysis thus provides a quantitative method to pinpoint the determinants of structural change on the atomic scale and also delineate the extent of propagation of the perturbation along the molecule. In addition to nucleic acids, this methodology is anticipated to be useful for studying conformational changes in all macromolecules, including carbohydrates, lipids, and proteins.

  16. Sustainable Energy Landscape: Implementing Energy Transition in the Physical Realm

    NARCIS (Netherlands)

    Stremke, S.

    2015-01-01

    Since the beginning of the new millennium, the concept of “energy landscape” is being discussed by academia from the environmental design domain while more and more practitioners have been contributing to sustainable energy transition. Yet, there remains some ambiguity as to what exactly is meant

  17. New Energy Landscapes of Pennsylvania: Forests to Farms to Fracking

    Science.gov (United States)

    Johnson, Deborah A.

    This dissertation adds to the literature on energy needed by industry, government, and citizens for decision-making. The pursuit to access or create new energy resources spawns new landscapes of energy in the early 21st century. The combination of hydraulic fracturing and horizontal drilling technologies---popularly called "fracking"---enables entry into previously inaccessible natural gas reserves such as the Marcellus shale much of which lies beneath Pennsylvania. Although this unconventional method offers a promising source of domestic energy and job growth, the potential for negative impacts raises concerns and questions. The questions include: What is the controversy about fracking in Pennsylvania? What are the impacts of fracking? What costs is Pennsylvania paying as it shifts to shale gas extraction? Are there activities taking place or material signs that point to the emerging new landscapes? Are the individuals and organizations that resist shale gas extraction---the so-called "Green Forces"---and others who live within the region of development more or less attuned to these costs? A mixed methods approach consists of landscape and stakeholder analyses including visual examination of GIS-generated maps, satellite images, and photos taken in the field specifically from four counties: Washington, Warren, McKean, and Bradford. Research captures stakeholders' voices across the public, government, and private sectors at different scales. A stakeholder matrix facilitates data organization and analysis. Data include 114 individual statements from an EPA Public Meeting, texts from 40 online-newspaper articles or blogs, and face-to-face interviews or focus group participation of 36 individuals. Further data come from a public health conference, industry convention, and public protest. The new energy landscape covers spaces in Pennsylvania where oil and gas development previously had not been present. It obscures as well as exposes the legacy of past energy

  18. Improved free-energy landscape reconstruction of bacteriorhodopsin highlights local variations in unfolding energy.

    Science.gov (United States)

    Heenan, Patrick R; Yu, Hao; Siewny, Matthew G W; Perkins, Thomas T

    2018-03-28

    Precisely quantifying the energetics that drive the folding of membrane proteins into a lipid bilayer remains challenging. More than 15 years ago, atomic force microscopy (AFM) emerged as a powerful tool to mechanically extract individual membrane proteins from a lipid bilayer. Concurrently, fluctuation theorems, such as the Jarzynski equality, were applied to deduce equilibrium free energies (ΔG 0 ) from non-equilibrium single-molecule force spectroscopy records. The combination of these two advances in single-molecule studies deduced the free-energy of the model membrane protein bacteriorhodopsin in its native lipid bilayer. To elucidate this free-energy landscape at a higher resolution, we applied two recent developments. First, as an input to the reconstruction, we used force-extension curves acquired with a 100-fold higher time resolution and 10-fold higher force precision than traditional AFM studies of membrane proteins. Next, by using an inverse Weierstrass transform and the Jarzynski equality, we removed the free energy associated with the force probe and determined the molecular free-energy landscape of the molecule under study, bacteriorhodopsin. The resulting landscape yielded an average unfolding free energy per amino acid (aa) of 1.0 ± 0.1 kcal/mol, in agreement with past single-molecule studies. Moreover, on a smaller spatial scale, this high-resolution landscape also agreed with an equilibrium measurement of a particular three-aa transition in bacteriorhodopsin that yielded 2.7 kcal/mol/aa, an unexpectedly high value. Hence, while average unfolding ΔG 0 per aa is a useful metric, the derived high-resolution landscape details significant local variation from the mean. More generally, we demonstrated that, as anticipated, the inverse Weierstrass transform is an efficient means to reconstruct free-energy landscapes from AFM data.

  19. Multiscale coarse-graining of the protein energy landscape.

    Directory of Open Access Journals (Sweden)

    Ronald D Hills

    2010-06-01

    Full Text Available A variety of coarse-grained (CG models exists for simulation of proteins. An outstanding problem is the construction of a CG model with physically accurate conformational energetics rivaling all-atom force fields. In the present work, atomistic simulations of peptide folding and aggregation equilibria are force-matched using multiscale coarse-graining to develop and test a CG interaction potential of general utility for the simulation of proteins of arbitrary sequence. The reduced representation relies on multiple interaction sites to maintain the anisotropic packing and polarity of individual sidechains. CG energy landscapes computed from replica exchange simulations of the folding of Trpzip, Trp-cage and adenylate kinase resemble those of other reduced representations; non-native structures are observed with energies similar to those of the native state. The artifactual stabilization of misfolded states implies that non-native interactions play a deciding role in deviations from ideal funnel-like cooperative folding. The role of surface tension, backbone hydrogen bonding and the smooth pairwise CG landscape is discussed. Ab initio folding aside, the improved treatment of sidechain rotamers results in stability of the native state in constant temperature simulations of Trpzip, Trp-cage, and the open to closed conformational transition of adenylate kinase, illustrating the potential value of the CG force field for simulating protein complexes and transitions between well-defined structural states.

  20. Protein energy landscapes determined by five-dimensional crystallography

    International Nuclear Information System (INIS)

    Schmidt, Marius; Srajer, Vukica; Henning, Robert; Ihee, Hyotcherl; Purwar, Namrta; Tenboer, Jason; Tripathi, Shailesh

    2013-01-01

    Barriers of activation within the photocycle of a photoactive protein were extracted from comprehensive time courses of time resolved crystallographic data collected at multiple temperature settings. Free-energy landscapes decisively determine the progress of enzymatically catalyzed reactions [Cornish-Bowden (2012 ▶), Fundamentals of Enzyme Kinetics, 4th ed.]. Time-resolved macromolecular crystallography unifies transient-state kinetics with structure determination [Moffat (2001 ▶), Chem. Rev.101, 1569–1581; Schmidt et al. (2005 ▶), Methods Mol. Biol.305, 115–154; Schmidt (2008 ▶), Ultrashort Laser Pulses in Medicine and Biology] because both can be determined from the same set of X-ray data. Here, it is demonstrated how barriers of activation can be determined solely from five-dimensional crystallography, where in addition to space and time, temperature is a variable as well [Schmidt et al. (2010 ▶), Acta Cryst. A66, 198–206]. Directly linking molecular structures with barriers of activation between them allows insight into the structural nature of the barrier to be gained. Comprehensive time series of crystallographic data at 14 different temperature settings were analyzed and the entropy and enthalpy contributions to the barriers of activation were determined. One hundred years after the discovery of X-ray scattering, these results advance X-ray structure determination to a new frontier: the determination of energy landscapes

  1. Technology assessment in energy landscapes. Agent-based modeling of energy conflicts

    International Nuclear Information System (INIS)

    Scheffran, Juergen; Link, P. Michael; Shaaban, Mostafa; Suesser, Diana

    2017-01-01

    The risks and conflicts of the fossil-nuclear age are in contrast to the effects of renewable energies which appear in a largely positive light. However, the transformation towards a low-carbon energy supply creates new energy landscapes with a high demand for suitable land areas - which may also provoke energy conflicts. Technology assessment can contribute to reducing such energy conflicts and increasing public acceptance by using spatial agent-based models that represent dynamic decisions and interactions of stakeholders regarding energy alternatives and land-use options. Northern Germany serves as a case study region where farmers and communities are local actors of the energy transition.

  2. Landscape of Future Accelerators at the Energy and Intensity Frontier

    Energy Technology Data Exchange (ETDEWEB)

    Syphers, M. J. [Northern Illinois U.; Chattopadhyay, S. [Northern Illinois U.

    2016-11-21

    An overview is provided of the currently envisaged landscape of charged particle accelerators at the energy and intensity frontiers to explore particle physics beyond the standard model via 1-100 TeV-scale lepton and hadron colliders and multi-Megawatt proton accelerators for short- and long- baseline neutrino experiments. The particle beam physics, associated technological challenges and progress to date for these accelerator facilities (LHC, HL-LHC, future 100 TeV p-p colliders, Tev-scale linear and circular electron-positron colliders, high intensity proton accelerator complex PIP-II for DUNE and future upgrade to PIP-III) are outlined. Potential and prospects for advanced “nonlinear dynamic techniques” at the multi-MW level intensity frontier and advanced “plasma- wakefield-based techniques” at the TeV-scale energy frontier and are also described.

  3. Hierarchical Protein Free Energy Landscapes from Variationally Enhanced Sampling.

    Science.gov (United States)

    Shaffer, Patrick; Valsson, Omar; Parrinello, Michele

    2016-12-13

    In recent work, we demonstrated that it is possible to obtain approximate representations of high-dimensional free energy surfaces with variationally enhanced sampling ( Shaffer, P.; Valsson, O.; Parrinello, M. Proc. Natl. Acad. Sci. , 2016 , 113 , 17 ). The high-dimensional spaces considered in that work were the set of backbone dihedral angles of a small peptide, Chignolin, and the high-dimensional free energy surface was approximated as the sum of many two-dimensional terms plus an additional term which represents an initial estimate. In this paper, we build on that work and demonstrate that we can calculate high-dimensional free energy surfaces of very high accuracy by incorporating additional terms. The additional terms apply to a set of collective variables which are more coarse than the base set of collective variables. In this way, it is possible to build hierarchical free energy surfaces, which are composed of terms that act on different length scales. We test the accuracy of these free energy landscapes for the proteins Chignolin and Trp-cage by constructing simple coarse-grained models and comparing results from the coarse-grained model to results from atomistic simulations. The approach described in this paper is ideally suited for problems in which the free energy surface has important features on different length scales or in which there is some natural hierarchy.

  4. Free energy landscape and molecular pathways of gas hydrate nucleation

    International Nuclear Information System (INIS)

    Bi, Yuanfei; Porras, Anna; Li, Tianshu

    2016-01-01

    Despite the significance of gas hydrates in diverse areas, a quantitative knowledge of hydrate formation at a molecular level is missing. The impediment to acquiring this understanding is primarily attributed to the stochastic nature and ultra-fine scales of nucleation events, posing a great challenge for both experiment and simulation to explore hydrate nucleation. Here we employ advanced molecular simulation methods, including forward flux sampling (FFS), p B histogram analysis, and backward flux sampling, to overcome the limit of direct molecular simulation for exploring both the free energy landscape and molecular pathways of hydrate nucleation. First we test the half-cage order parameter (H-COP) which we developed for driving FFS, through conducting the p B histogram analysis. Our results indeed show that H-COP describes well the reaction coordinates of hydrate nucleation. Through the verified order parameter, we then directly compute the free energy landscape for hydrate nucleation by combining both forward and backward flux sampling. The calculated stationary distribution density, which is obtained independently of nucleation theory, is found to fit well against the classical nucleation theory (CNT). Subsequent analysis of the obtained large ensemble of hydrate nucleation trajectories show that although on average, hydrate formation is facilitated by a two-step like mechanism involving a gradual transition from an amorphous to a crystalline structure, there also exist nucleation pathways where hydrate crystallizes directly, without going through the amorphous stage. The CNT-like free energy profile and the structural diversity suggest the existence of multiple active transition pathways for hydrate nucleation, and possibly also imply the near degeneracy in their free energy profiles among different pathways. Our results thus bring a new perspective to the long standing question of how hydrates crystallize.

  5. Free energy landscape and molecular pathways of gas hydrate nucleation.

    Science.gov (United States)

    Bi, Yuanfei; Porras, Anna; Li, Tianshu

    2016-12-07

    Despite the significance of gas hydrates in diverse areas, a quantitative knowledge of hydrate formation at a molecular level is missing. The impediment to acquiring this understanding is primarily attributed to the stochastic nature and ultra-fine scales of nucleation events, posing a great challenge for both experiment and simulation to explore hydrate nucleation. Here we employ advanced molecular simulation methods, including forward flux sampling (FFS), p B histogram analysis, and backward flux sampling, to overcome the limit of direct molecular simulation for exploring both the free energy landscape and molecular pathways of hydrate nucleation. First we test the half-cage order parameter (H-COP) which we developed for driving FFS, through conducting the p B histogram analysis. Our results indeed show that H-COP describes well the reaction coordinates of hydrate nucleation. Through the verified order parameter, we then directly compute the free energy landscape for hydrate nucleation by combining both forward and backward flux sampling. The calculated stationary distribution density, which is obtained independently of nucleation theory, is found to fit well against the classical nucleation theory (CNT). Subsequent analysis of the obtained large ensemble of hydrate nucleation trajectories show that although on average, hydrate formation is facilitated by a two-step like mechanism involving a gradual transition from an amorphous to a crystalline structure, there also exist nucleation pathways where hydrate crystallizes directly, without going through the amorphous stage. The CNT-like free energy profile and the structural diversity suggest the existence of multiple active transition pathways for hydrate nucleation, and possibly also imply the near degeneracy in their free energy profiles among different pathways. Our results thus bring a new perspective to the long standing question of how hydrates crystallize.

  6. Free energy landscape and molecular pathways of gas hydrate nucleation

    Energy Technology Data Exchange (ETDEWEB)

    Bi, Yuanfei; Porras, Anna; Li, Tianshu, E-mail: tsli@gwu.edu [Department of Civil and Environmental Engineering, George Washington University, Washington DC 20052 (United States)

    2016-12-07

    Despite the significance of gas hydrates in diverse areas, a quantitative knowledge of hydrate formation at a molecular level is missing. The impediment to acquiring this understanding is primarily attributed to the stochastic nature and ultra-fine scales of nucleation events, posing a great challenge for both experiment and simulation to explore hydrate nucleation. Here we employ advanced molecular simulation methods, including forward flux sampling (FFS), p{sub B} histogram analysis, and backward flux sampling, to overcome the limit of direct molecular simulation for exploring both the free energy landscape and molecular pathways of hydrate nucleation. First we test the half-cage order parameter (H-COP) which we developed for driving FFS, through conducting the p{sub B} histogram analysis. Our results indeed show that H-COP describes well the reaction coordinates of hydrate nucleation. Through the verified order parameter, we then directly compute the free energy landscape for hydrate nucleation by combining both forward and backward flux sampling. The calculated stationary distribution density, which is obtained independently of nucleation theory, is found to fit well against the classical nucleation theory (CNT). Subsequent analysis of the obtained large ensemble of hydrate nucleation trajectories show that although on average, hydrate formation is facilitated by a two-step like mechanism involving a gradual transition from an amorphous to a crystalline structure, there also exist nucleation pathways where hydrate crystallizes directly, without going through the amorphous stage. The CNT-like free energy profile and the structural diversity suggest the existence of multiple active transition pathways for hydrate nucleation, and possibly also imply the near degeneracy in their free energy profiles among different pathways. Our results thus bring a new perspective to the long standing question of how hydrates crystallize.

  7. Trp-cage: Folding free energy landscape in explicit water

    Science.gov (United States)

    Zhou, Ruhong

    2003-11-01

    Trp-cage is a 20-residue miniprotein, which is believed to be the fastest folder known so far. In this study, the folding free energy landscape of Trp-cage has been explored in explicit solvent by using an OPLSAA force field with periodic boundary condition. A highly parallel replica exchange molecular dynamics method is used for the conformation space sampling, with the help of a recently developed efficient molecular dynamics algorithm P3ME/RESPA (particle-particle particle-mesh Ewald/reference system propagator algorithm). A two-step folding mechanism is proposed that involves an intermediate state where two correctly formed partial hydrophobic cores are separated by an essential salt-bridge between residues Asp-9 and Arg-16 near the center of the peptide. This metastable intermediate state provides an explanation for the superfast folding process. The free energy landscape is found to be rugged at low temperatures, and then becomes smooth and funnel-like above 340 K. The lowest free energy structure at 300 K is only 1.50 Å C-RMSD (C-rms deviation) from the NMR structures. The simulated nuclear Overhauser effect pair distances are in excellent agreement with the raw NMR data. The temperature dependence of the Trp-cage population, however, is found to be significantly different from experiment, with a much higher melting transition temperature above 400 K (experimental 315 K), indicating that the current force fields, parameterized at room temperature, need to be improved to correctly predict the temperature dependence.

  8. Multivariable extrapolation of grand canonical free energy landscapes

    Science.gov (United States)

    Mahynski, Nathan A.; Errington, Jeffrey R.; Shen, Vincent K.

    2017-12-01

    We derive an approach for extrapolating the free energy landscape of multicomponent systems in the grand canonical ensemble, obtained from flat-histogram Monte Carlo simulations, from one set of temperature and chemical potentials to another. This is accomplished by expanding the landscape in a Taylor series at each value of the order parameter which defines its macrostate phase space. The coefficients in each Taylor polynomial are known exactly from fluctuation formulas, which may be computed by measuring the appropriate moments of extensive variables that fluctuate in this ensemble. Here we derive the expressions necessary to define these coefficients up to arbitrary order. In principle, this enables a single flat-histogram simulation to provide complete thermodynamic information over a broad range of temperatures and chemical potentials. Using this, we also show how to combine a small number of simulations, each performed at different conditions, in a thermodynamically consistent fashion to accurately compute properties at arbitrary temperatures and chemical potentials. This method may significantly increase the computational efficiency of biased grand canonical Monte Carlo simulations, especially for multicomponent mixtures. Although approximate, this approach is amenable to high-throughput and data-intensive investigations where it is preferable to have a large quantity of reasonably accurate simulation data, rather than a smaller amount with a higher accuracy.

  9. Approximate scaling properties of RNA free energy landscapes

    Science.gov (United States)

    Baskaran, S.; Stadler, P. F.; Schuster, P.

    1996-01-01

    RNA free energy landscapes are analysed by means of "time-series" that are obtained from random walks restricted to excursion sets. The power spectra, the scaling of the jump size distribution, and the scaling of the curve length measured with different yard stick lengths are used to describe the structure of these "time series". Although they are stationary by construction, we find that their local behavior is consistent with both AR(1) and self-affine processes. Random walks confined to excursion sets (i.e., with the restriction that the fitness value exceeds a certain threshold at each step) exhibit essentially the same statistics as free random walks. We find that an AR(1) time series is in general approximately self-affine on timescales up to approximately the correlation length. We present an empirical relation between the correlation parameter rho of the AR(1) model and the exponents characterizing self-affinity.

  10. Temporal disconnectivity of the energy landscape in glassy systems

    Science.gov (United States)

    Lempesis, Nikolaos; Boulougouris, Georgios C.; Theodorou, Doros N.

    2013-03-01

    An alternative graphical representation of the potential energy landscape (PEL) has been developed and applied to a binary Lennard-Jones glassy system, providing insight into the unique topology of the system's potential energy hypersurface. With the help of this representation one is able to monitor the different explored basins of the PEL, as well as how - and mainly when - subsets of basins communicate with each other via transitions in such a way that details of the prior temporal history have been erased, i.e., local equilibration between the basins in each subset has been achieved. In this way, apart from detailed information about the structure of the PEL, the system's temporal evolution on the PEL is described. In order to gather all necessary information about the identities of two or more basins that are connected with each other, we consider two different approaches. The first one is based on consideration of the time needed for two basins to mutually equilibrate their populations according to the transition rate between them, in the absence of any effect induced by the rest of the landscape. The second approach is based on an analytical solution of the master equation that explicitly takes into account the entire explored landscape. It is shown that both approaches lead to the same result concerning the topology of the PEL and dynamical evolution on it. Moreover, a "temporal disconnectivity graph" is introduced to represent a lumped system stemming from the initial one. The lumped system is obtained via a specially designed algorithm [N. Lempesis, D. G. Tsalikis, G. C. Boulougouris, and D. N. Theodorou, J. Chem. Phys. 135, 204507 (2011), 10.1063/1.3663207]. The temporal disconnectivity graph provides useful information about both the lumped and the initial systems, including the definition of "metabasins" as collections of basins that communicate with each other via transitions that are fast relative to the observation time. Finally, the two examined

  11. Discrete kinetic models from funneled energy landscape simulations.

    Directory of Open Access Journals (Sweden)

    Nicholas P Schafer

    Full Text Available A general method for facilitating the interpretation of computer simulations of protein folding with minimally frustrated energy landscapes is detailed and applied to a designed ankyrin repeat protein (4ANK. In the method, groups of residues are assigned to foldons and these foldons are used to map the conformational space of the protein onto a set of discrete macrobasins. The free energies of the individual macrobasins are then calculated, informing practical kinetic analysis. Two simple assumptions about the universality of the rate for downhill transitions between macrobasins and the natural local connectivity between macrobasins lead to a scheme for predicting overall folding and unfolding rates, generating chevron plots under varying thermodynamic conditions, and inferring dominant kinetic folding pathways. To illustrate the approach, free energies of macrobasins were calculated from biased simulations of a non-additive structure-based model using two structurally motivated foldon definitions at the full and half ankyrin repeat resolutions. The calculated chevrons have features consistent with those measured in stopped flow chemical denaturation experiments. The dominant inferred folding pathway has an "inside-out", nucleation-propagation like character.

  12. Free energy landscape of a minimalist salt bridge model.

    Science.gov (United States)

    Li, Xubin; Lv, Chao; Corbett, Karen M; Zheng, Lianqing; Wu, Dongsheng; Yang, Wei

    2016-01-01

    Salt bridges are essential to protein stability and dynamics. Despite the importance, there has been scarce of detailed discussion on how salt bridge partners interact with each other in distinct solvent exposed environments. In this study, employing a recent generalized orthogonal space tempering (gOST) method, we enabled efficient molecular dynamics simulation of repetitive breaking and reforming of salt bridge structures within a minimalist salt-bridge model, the Asp-Arg dipeptide and thereby were able to map its detailed free energy landscape in aqueous solution. Free energy surface analysis shows that although individually-solvated states are more favorable, salt-bridge states still occupy a noticeable portion of the overall population. Notably, the competing forces, e.g. intercharge attractions that drive the formation of salt bridges and solvation forces that pull the charged groups away from each other, are energetically comparable. As the result, the salt bridge stability is highly tunable by local environments; for instance when local water molecules are perturbed to interact more strongly with each other, the population of the salt-bridge states is likely to increase. Our results reveal the critical role of local solvent structures in modulating salt-bridge partner interactions and imply the importance of water fluctuations on conformational dynamics that involves solvent accessible salt bridge formations. © 2015 The Protein Society.

  13. Bayesian energy landscape tilting: towards concordant models of molecular ensembles.

    Science.gov (United States)

    Beauchamp, Kyle A; Pande, Vijay S; Das, Rhiju

    2014-03-18

    Predicting biological structure has remained challenging for systems such as disordered proteins that take on myriad conformations. Hybrid simulation/experiment strategies have been undermined by difficulties in evaluating errors from computational model inaccuracies and data uncertainties. Building on recent proposals from maximum entropy theory and nonequilibrium thermodynamics, we address these issues through a Bayesian energy landscape tilting (BELT) scheme for computing Bayesian hyperensembles over conformational ensembles. BELT uses Markov chain Monte Carlo to directly sample maximum-entropy conformational ensembles consistent with a set of input experimental observables. To test this framework, we apply BELT to model trialanine, starting from disagreeing simulations with the force fields ff96, ff99, ff99sbnmr-ildn, CHARMM27, and OPLS-AA. BELT incorporation of limited chemical shift and (3)J measurements gives convergent values of the peptide's α, β, and PPII conformational populations in all cases. As a test of predictive power, all five BELT hyperensembles recover set-aside measurements not used in the fitting and report accurate errors, even when starting from highly inaccurate simulations. BELT's principled framework thus enables practical predictions for complex biomolecular systems from discordant simulations and sparse data. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  14. Computational design of RNAs with complex energy landscapes.

    Science.gov (United States)

    Höner zu Siederdissen, Christian; Hammer, Stefan; Abfalter, Ingrid; Hofacker, Ivo L; Flamm, Christoph; Stadler, Peter F

    2013-12-01

    RNA has become an integral building material in synthetic biology. Dominated by their secondary structures, which can be computed efficiently, RNA molecules are amenable not only to in vitro and in vivo selection, but also to rational, computation-based design. While the inverse folding problem of constructing an RNA sequence with a prescribed ground-state structure has received considerable attention for nearly two decades, there have been few efforts to design RNAs that can switch between distinct prescribed conformations. We introduce a user-friendly tool for designing RNA sequences that fold into multiple target structures. The underlying algorithm makes use of a combination of graph coloring and heuristic local optimization to find sequences whose energy landscapes are dominated by the prescribed conformations. A flexible interface allows the specification of a wide range of design goals. We demonstrate that bi- and tri-stable "switches" can be designed easily with moderate computational effort for the vast majority of compatible combinations of desired target structures. RNAdesign is freely available under the GPL-v3 license. Copyright © 2013 Wiley Periodicals, Inc.

  15. Relationship between energy landscape and low-temperature dynamics of ±J spin glasses

    International Nuclear Information System (INIS)

    Kobe, S.; Krawczyk, J.

    2004-01-01

    Clusters and valleys in the exact low-energy landscape of finite Edwards-Anderson ±J spin glasses are related to the distribution of spin domains and free spins in the ground states. The time evolution of the spin correlation function reflects a walk through the landscape at a given temperature and shows typical glassy behaviour

  16. Landscape and Energy%景观和能源

    Institute of Scientific and Technical Information of China (English)

    德克·西蒙斯; 李佳怿(译); 吴晓彤(校)

    2016-01-01

    research-through-design projects. The Rotterdam case is produced with local stakeholders for the 2014 ‘Landscape and Energy’ book publication. This land-oriented case is complemented by a project on the seascape of the North Sea as a future energy landscape in the IABR-2016 project 2050: An Energetic Odyssey. Especialy the last case not only justifies the conclusion that landscape architecture can play a role but also that research-by-design is a strong instrument to help in policy making.

  17. Conference on landscape impacts of wind energy and local acceptance: France-Germany crossed views

    International Nuclear Information System (INIS)

    Bouscatel, Jerome; Olagne, Regis; Derkenne, Chantal; Galiano, Mila; Mayer, Joerg; Ratzbor, Guenter; Laborgne, Pia; Nadai, Alain; Ratouis, Marie-Odile; Schoebel-Rutschmann, Soeren; Petit, Jean-Francois; Guennewig, Dieter; Portales, David

    2008-01-01

    The French-German office for Renewable energies (OFAEnR) organised a conference on the landscape impacts of wind energy. In the framework of this French-German exchange of experience, more than 100 participants exchanged views on the environmental impact of wind farms and the opinion of residents. This document brings together the available presentations (slides) made during this event: 1 - French people and wind energy (Mila Galiano); 2 - Wind energy acceptance in Germany: an essential factor for the wind industry development (Joerg Mayer); 3 - Taking into account landscapes and residents in the development of wind farms: a France-Germany comparison (Pia Laborgne, Alain Nadai); 3 - Wind energy development supervision thanks to territorial planning in Germany (Guenter Ratzbor); 4 - Landscape challenges in wind energy development: point of view and role of a state decentralised department (Marie-Odile Ratouis); 5 - Park or landscape - Wind turbines as elements of the cultural landscape (Soeren Schoebel-Rutschmann); 6 - How should a developer approach the 'landscape' aspect when foreseeing a wind energy project installation (Jean-Francois Petit); 7 - More consensual wind energy projects along highways, railways and overhead power lines? (Dieter Guennewig); 8 - The 'wings top': un example of participatory and citizen's project (David Portales)

  18. The free energy landscape of small molecule unbinding.

    Directory of Open Access Journals (Sweden)

    Danzhi Huang

    2011-02-01

    Full Text Available The spontaneous dissociation of six small ligands from the active site of FKBP (the FK506 binding protein is investigated by explicit water molecular dynamics simulations and network analysis. The ligands have between four (dimethylsulphoxide and eleven (5-diethylamino-2-pentanone non-hydrogen atoms, and an affinity for FKBP ranging from 20 to 0.2 mM. The conformations of the FKBP/ligand complex saved along multiple trajectories (50 runs at 310 K for each ligand are grouped according to a set of intermolecular distances into nodes of a network, and the direct transitions between them are the links. The network analysis reveals that the bound state consists of several subbasins, i.e., binding modes characterized by distinct intermolecular hydrogen bonds and hydrophobic contacts. The dissociation kinetics show a simple (i.e., single-exponential time dependence because the unbinding barrier is much higher than the barriers between subbasins in the bound state. The unbinding transition state is made up of heterogeneous positions and orientations of the ligand in the FKBP active site, which correspond to multiple pathways of dissociation. For the six small ligands of FKBP, the weaker the binding affinity the closer to the bound state (along the intermolecular distance are the transition state structures, which is a new manifestation of Hammond behavior. Experimental approaches to the study of fragment binding to proteins have limitations in temporal and spatial resolution. Our network analysis of the unbinding simulations of small inhibitors from an enzyme paints a clear picture of the free energy landscape (both thermodynamics and kinetics of ligand unbinding.

  19. Dynamic energy landscapes of riboswitches help interpret conformational rearrangements and function.

    Directory of Open Access Journals (Sweden)

    Giulio Quarta

    Full Text Available Riboswitches are RNAs that modulate gene expression by ligand-induced conformational changes. However, the way in which sequence dictates alternative folding pathways of gene regulation remains unclear. In this study, we compute energy landscapes, which describe the accessible secondary structures for a range of sequence lengths, to analyze the transcriptional process as a given sequence elongates to full length. In line with experimental evidence, we find that most riboswitch landscapes can be characterized by three broad classes as a function of sequence length in terms of the distribution and barrier type of the conformational clusters: low-barrier landscape with an ensemble of different conformations in equilibrium before encountering a substrate; barrier-free landscape in which a direct, dominant "downhill" pathway to the minimum free energy structure is apparent; and a barrier-dominated landscape with two isolated conformational states, each associated with a different biological function. Sharing concepts with the "new view" of protein folding energy landscapes, we term the three sequence ranges above as the sensing, downhill folding, and functional windows, respectively. We find that these energy landscape patterns are conserved in various riboswitch classes, though the order of the windows may vary. In fact, the order of the three windows suggests either kinetic or thermodynamic control of ligand binding. These findings help understand riboswitch structure/function relationships and open new avenues to riboswitch design.

  20. Numerical evaluation of the statistical properties of a potential energy landscape

    International Nuclear Information System (INIS)

    Nave, E La; Sciortino, F; Tartaglia, P; Michele, C De; Mossa, S

    2003-01-01

    The techniques which allow the numerical evaluation of the statistical properties of the potential energy landscape for models of simple liquids are reviewed and critically discussed. Expressions for the liquid free energy and its vibrational and configurational components are reported. Finally, a possible model for the statistical properties of the landscape, which appears to describe correctly fragile liquids in the region where equilibrium simulations are feasible, is discussed

  1. Energy Transition: Missed Opportunities and Emerging Challenges for Landscape Planning and Designing

    Directory of Open Access Journals (Sweden)

    Renée M. de Waal

    2014-07-01

    Full Text Available Making the shift from fossil fuels to renewable energy seems inevitable. Because energy transition poses new challenges and opportunities to the discipline of landscape architecture, the questions addressed in this paper are: (1 what landscape architects can learn from successful energy transitions in Güssing, Jühnde and Samsø; and (2 to what extent landscape architecture (or other spatial disciplines contributed to energy transition in the aforementioned cases. An exploratory, comparative case study was conducted to identify differences and similarities among the cases, to answer the research questions, and to formulate recommendations for further research and practice. The comparison indicated that the realized renewable energy systems are context-dependent and, therefore, specifically designed to meet the respective energy demand, making use of the available potentials for renewable energy generation and efficiency. Further success factors seemed to be the presence of (local frontrunners and a certain degree of citizen participation. The relatively smooth implementation of renewable energy technologies in Jühnde and on Samsø may indicate the importance of careful and (partly institutionalized consideration of landscape impact, siting and design. Comparing the cases against the literature demonstrated that landscape architects were not as involved as they, theoretically, could have been. However, particularly when the aim is sustainable development, rather than “merely” renewable energy provision, the integrative concept of “sustainable energy landscapes” can be the arena where landscape architecture and other disciplines meet to pursue global sustainability goals, while empowering local communities and safeguarding landscape quality.

  2. Reliable protein folding on non-funneled energy landscapes: the free energy reaction path

    OpenAIRE

    Lois, Gregg; Blawzdziewicz, Jerzy; O'Hern, Corey S.

    2008-01-01

    A theoretical framework is developed to study the dynamics of protein folding. The key insight is that the search for the native protein conformation is influenced by the rate r at which external parameters, such as temperature, chemical denaturant or pH, are adjusted to induce folding. A theory based on this insight predicts that (1) proteins with non-funneled energy landscapes can fold reliably to their native state, (2) reliable folding can occur as an equilibrium or out-of-equilibrium pro...

  3. Chemical Denaturants Smoothen Ruggedness on the Free Energy Landscape of Protein Folding.

    Science.gov (United States)

    Malhotra, Pooja; Jethva, Prashant N; Udgaonkar, Jayant B

    2017-08-08

    To characterize experimentally the ruggedness of the free energy landscape of protein folding is challenging, because the distributed small free energy barriers are usually dominated by one, or a few, large activation free energy barriers. This study delineates changes in the roughness of the free energy landscape by making use of the observation that a decrease in ruggedness is accompanied invariably by an increase in folding cooperativity. Hydrogen exchange (HX) coupled to mass spectrometry was used to detect transient sampling of local energy minima and the global unfolded state on the free energy landscape of the small protein single-chain monellin. Under native conditions, local noncooperative openings result in interconversions between Boltzmann-distributed intermediate states, populated on an extremely rugged "uphill" energy landscape. The cooperativity of these interconversions was increased by selectively destabilizing the native state via mutations, and further by the addition of a chemical denaturant. The perturbation of stability alone resulted in seven backbone amide sites exchanging cooperatively. The size of the cooperatively exchanging and/or unfolding unit did not depend on the extent of protein destabilization. Only upon the addition of a denaturant to a destabilized mutant variant did seven additional backbone amide sites exchange cooperatively. Segmentwise analysis of the HX kinetics of the mutant variants further confirmed that the observed increase in cooperativity was due to the smoothing of the ruggedness of the free energy landscape of folding of the protein by the chemical denaturant.

  4. Incorporating Renewable Energy Science in Regional Landscape Design: Results from a Competition in The Netherlands

    Directory of Open Access Journals (Sweden)

    Renée M. de Waal

    2015-04-01

    Full Text Available Energy transition is expected to make an important contribution to sustainable development. Although it is argued that landscape design could foster energy transition, there is scant empirical research on how practitioners approach this new challenge. The research question central to this study is: To what extent and how is renewable energy science incorporated in regional landscape design? To address this knowledge gap, a case study of a regional landscape design competition in the Netherlands, held from 2010–2012, is presented. Its focus was on integral, strategic landscape transformation with energy transition as a major theme. Content analysis of the 36 competition entries was supplemented and triangulated with a survey among the entrants, observation of the process and a study of the competition documents and website. Results indicated insufficient use of key-strategies elaborated by renewable energy science. If landscape design wants to adopt a supportive role towards energy transition, a well-informed and evidence-based approach is highly recommended. Nevertheless, promising strategies for addressing the complex process of ensuring sustainable energy transition also emerged. They include the careful cultivation of public support by developing inclusive and bottom-up processes, and balancing energy-conscious interventions with other land uses and interests.

  5. Distinguishing effect of buffing vs. grinding, milling and turning operations on the chloride induced SCC susceptibility of 304L austenitic stainless steel

    International Nuclear Information System (INIS)

    Kumar, Pandu Sunil; Acharyya, Swati Ghosh; Rao, S.V. Ramana; Kapoor, Komal

    2017-01-01

    The study compares the effect of different surface working operations like grinding, milling, turning and buffing on the Cl – induced stress corrosion cracking (SCC) susceptibility of austenitic 304L stainless steel (SS) in a chloride environment. SS 304L was subjected to four different surface working operations namely grinding, milling, turning and buffing. The residual stress distribution of the surface as a result of machining was measured by X-ray diffraction. The Cl – induced SCC susceptibility of the different surface worked samples were determined by testing in boiling magnesium chloride as per ASTM G36 for 3 h, 9 h and 72 h. The surface and cross section of the samples both pre and post exposure to the corrosive medium was characterized using optical microscopy, scanning electron microscopy (SEM). The study revealed that grinding, milling and turning operations resulted in high tensile residual stresses on the surface together with the high density of deformation bands making these surfaces highly susceptible to Cl – induced SCC. On the other hand buffing produces compressive residual stresses on the surface with minimal plastic strain, making it more resistance to Cl – induced SCC. The study highlights that the conventional machining operations on 304L SS surfaces should be invariably followed by buffing operation to make the surfaces more resistance to SCC. - Highlights: • Grinding, milling and turning lead to tensile residual stresses and plastic strain. • Buffing leads to compressive residual stresses on the surface and minimal strain. • Grinding, milling and turning make 304L SS surface susceptible to SCC. • Buffed 304L SS surface is immune to SCC. • Grinding, milling, and turning operations should be followed by buffing operation.

  6. Distinguishing effect of buffing vs. grinding, milling and turning operations on the chloride induced SCC susceptibility of 304L austenitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Pandu Sunil [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); Acharyya, Swati Ghosh, E-mail: swati364@gmail.com [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); Rao, S.V. Ramana; Kapoor, Komal [Nuclear Fuel Complex, Department of Atomic Energy, Government of India, Hyderabad 500062 (India)

    2017-02-27

    The study compares the effect of different surface working operations like grinding, milling, turning and buffing on the Cl{sup –} induced stress corrosion cracking (SCC) susceptibility of austenitic 304L stainless steel (SS) in a chloride environment. SS 304L was subjected to four different surface working operations namely grinding, milling, turning and buffing. The residual stress distribution of the surface as a result of machining was measured by X-ray diffraction. The Cl{sup –} induced SCC susceptibility of the different surface worked samples were determined by testing in boiling magnesium chloride as per ASTM G36 for 3 h, 9 h and 72 h. The surface and cross section of the samples both pre and post exposure to the corrosive medium was characterized using optical microscopy, scanning electron microscopy (SEM). The study revealed that grinding, milling and turning operations resulted in high tensile residual stresses on the surface together with the high density of deformation bands making these surfaces highly susceptible to Cl{sup –} induced SCC. On the other hand buffing produces compressive residual stresses on the surface with minimal plastic strain, making it more resistance to Cl{sup –} induced SCC. The study highlights that the conventional machining operations on 304L SS surfaces should be invariably followed by buffing operation to make the surfaces more resistance to SCC. - Highlights: • Grinding, milling and turning lead to tensile residual stresses and plastic strain. • Buffing leads to compressive residual stresses on the surface and minimal strain. • Grinding, milling and turning make 304L SS surface susceptible to SCC. • Buffed 304L SS surface is immune to SCC. • Grinding, milling, and turning operations should be followed by buffing operation.

  7. Specificity and affinity quantification of flexible recognition from underlying energy landscape topography.

    Directory of Open Access Journals (Sweden)

    Xiakun Chu

    2014-08-01

    Full Text Available Flexibility in biomolecular recognition is essential and critical for many cellular activities. Flexible recognition often leads to moderate affinity but high specificity, in contradiction with the conventional wisdom that high affinity and high specificity are coupled. Furthermore, quantitative understanding of the role of flexibility in biomolecular recognition is still challenging. Here, we meet the challenge by quantifying the intrinsic biomolecular recognition energy landscapes with and without flexibility through the underlying density of states. We quantified the thermodynamic intrinsic specificity by the topography of the intrinsic binding energy landscape and the kinetic specificity by association rate. We found that the thermodynamic and kinetic specificity are strongly correlated. Furthermore, we found that flexibility decreases binding affinity on one hand, but increases binding specificity on the other hand, and the decreasing or increasing proportion of affinity and specificity are strongly correlated with the degree of flexibility. This shows more (less flexibility leads to weaker (stronger coupling between affinity and specificity. Our work provides a theoretical foundation and quantitative explanation of the previous qualitative studies on the relationship among flexibility, affinity and specificity. In addition, we found that the folding energy landscapes are more funneled with binding, indicating that binding helps folding during the recognition. Finally, we demonstrated that the whole binding-folding energy landscapes can be integrated by the rigid binding and isolated folding energy landscapes under weak flexibility. Our results provide a novel way to quantify the affinity and specificity in flexible biomolecular recognition.

  8. Impacts of renewable energy on landscape. Alternative of offshore wind in marine areas

    Directory of Open Access Journals (Sweden)

    Francesca Moraci

    2014-01-01

    Full Text Available The effects determined in the landscape by plants powered by renewable sources represent some unresolved issues in terms of visual and landscape impact mitigation in general. These aspects relate to the landscape are recognized in all types of impact with due attention to the various components and dynamics involved identifiable in the landscape of reference.The wind power plants, in particular, while making unquestionable environmental benefits thanks to the production of energy from renewable sources, but imposes a significant cost to the landscape with the installation of wind turbines in contexts necessarily favorable to impact,  interrupting the skyline, creating territorial discontinuities, "subtracting" and altering the landscape in the absence of effective mitigation works.The environmental compatibility of the proposed solutions depends primarily on the location of wind farms.Is necessary indicate  an overall strategy, a shared model of planning and land management, as in other European countries such as Denmark, Germany, France and the United Kingdom where the choice of locating wind farms has resulted in a new draft territory, construction and redesign of the landscape.

  9. Is the fenamate group a polymorphophore?: contrasting the crystal energy landscapes of fenamic and tolfenamic acids

    NARCIS (Netherlands)

    Uzoh, O.G.; Cruz-Cabeza, A.J.; Price, S. L.

    2012-01-01

    The concept of a polymorphophore was investigated by contrasting the crystal energy landscapes of monomorphic fenamic acid (2-(phenylamino)-benzoic acid, FA) and one of its highly polymorphic derivatives, tolfenamic acid (2-[(3-chloro-2-methylphenyl)amino]-benzoic acid, TA). The crystal energy

  10. Linking habitat selection to fitness-related traits in herbivores: the role of the energy landscape

    Science.gov (United States)

    Ryan A. Long; R. T. Bowyer; Warren P. Porter; Paul Mathewson; Kevin L. Monteith; Scott L. Findholt; Brian L. Dick; John G. Kie

    2016-01-01

    Animals may partially overcome environmental constraints on fitness by behaviorally adjusting their exposure to costs and supplies of energy. Few studies, however, have linked spatiotemporal variation in the energy landscape to behaviorally mediated measures of performance that ostensibly influence individual fitness. We hypothesized that strength of selection by North...

  11. The inverted free energy landscape of an intrinsically disordered peptide by simulations and experiments.

    Science.gov (United States)

    Granata, Daniele; Baftizadeh, Fahimeh; Habchi, Johnny; Galvagnion, Celine; De Simone, Alfonso; Camilloni, Carlo; Laio, Alessandro; Vendruscolo, Michele

    2015-10-26

    The free energy landscape theory has been very successful in rationalizing the folding behaviour of globular proteins, as this representation provides intuitive information on the number of states involved in the folding process, their populations and pathways of interconversion. We extend here this formalism to the case of the Aβ40 peptide, a 40-residue intrinsically disordered protein fragment associated with Alzheimer's disease. By using an advanced sampling technique that enables free energy calculations to reach convergence also in the case of highly disordered states of proteins, we provide a precise structural characterization of the free energy landscape of this peptide. We find that such landscape has inverted features with respect to those typical of folded proteins. While the global free energy minimum consists of highly disordered structures, higher free energy regions correspond to a large variety of transiently structured conformations with secondary structure elements arranged in several different manners, and are not separated from each other by sizeable free energy barriers. From this peculiar structure of the free energy landscape we predict that this peptide should become more structured and not only more compact, with increasing temperatures, and we show that this is the case through a series of biophysical measurements.

  12. Control of the Effective Free-Energy Landscape in a Frustrated Magnet by a Field Pulse

    Science.gov (United States)

    Wan, Yuan; Moessner, Roderich

    2017-10-01

    Thermal fluctuations can lift the degeneracy of a ground state manifold, producing a free-energy landscape without accidentally degenerate minima. In a process known as order by disorder, a subset of states incorporating symmetry breaking may be selected. Here, we show that such a free-energy landscape can be controlled in a nonequilibrium setting as the slow motion within the ground state manifold is governed by the fast modes out of it. For the paradigmatic case of the classical pyrochlore X Y antiferromagnet, we show that a uniform magnetic field pulse can excite these fast modes to generate a tunable effective free-energy landscape with minima at thermodynamically unstable portions of the ground state manifold.

  13. Quantifying the topography of the intrinsic energy landscape of flexible biomolecular recognition

    Science.gov (United States)

    Chu, Xiakun; Gan, Linfeng; Wang, Erkang; Wang, Jin

    2013-01-01

    Biomolecular functions are determined by their interactions with other molecules. Biomolecular recognition is often flexible and associated with large conformational changes involving both binding and folding. However, the global and physical understanding for the process is still challenging. Here, we quantified the intrinsic energy landscapes of flexible biomolecular recognition in terms of binding–folding dynamics for 15 homodimers by exploring the underlying density of states, using a structure-based model both with and without considering energetic roughness. By quantifying three individual effective intrinsic energy landscapes (one for interfacial binding, two for monomeric folding), the association mechanisms for flexible recognition of 15 homodimers can be classified into two-state cooperative “coupled binding–folding” and three-state noncooperative “folding prior to binding” scenarios. We found that the association mechanism of flexible biomolecular recognition relies on the interplay between the underlying effective intrinsic binding and folding energy landscapes. By quantifying the whole global intrinsic binding–folding energy landscapes, we found strong correlations between the landscape topography measure Λ (dimensionless ratio of energy gap versus roughness modulated by the configurational entropy) and the ratio of the thermodynamic stable temperature versus trapping temperature, as well as between Λ and binding kinetics. Therefore, the global energy landscape topography determines the binding–folding thermodynamics and kinetics, crucial for the feasibility and efficiency of realizing biomolecular function. We also found “U-shape” temperature-dependent kinetic behavior and a dynamical cross-over temperature for dividing exponential and nonexponential kinetics for two-state homodimers. Our study provides a unique way to bridge the gap between theory and experiments. PMID:23754431

  14. Connecting the kinetics and energy landscape of tRNA translocation on the ribosome.

    Directory of Open Access Journals (Sweden)

    Paul C Whitford

    Full Text Available Functional rearrangements in biomolecular assemblies result from diffusion across an underlying energy landscape. While bulk kinetic measurements rely on discrete state-like approximations to the energy landscape, single-molecule methods can project the free energy onto specific coordinates. With measures of the diffusion, one may establish a quantitative bridge between state-like kinetic measurements and the continuous energy landscape. We used an all-atom molecular dynamics simulation of the 70S ribosome (2.1 million atoms; 1.3 microseconds to provide this bridge for specific conformational events associated with the process of tRNA translocation. Starting from a pre-translocation configuration, we identified sets of residues that collectively undergo rotary rearrangements implicated in ribosome function. Estimates of the diffusion coefficients along these collective coordinates for translocation were then used to interconvert between experimental rates and measures of the energy landscape. This analysis, in conjunction with previously reported experimental rates of translocation, provides an upper-bound estimate of the free-energy barriers associated with translocation. While this analysis was performed for a particular kinetic scheme of translocation, the quantitative framework is general and may be applied to energetic and kinetic descriptions that include any number of intermediates and transition states.

  15. Another possible energy landscape; Un autre paysage energetique possible

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-06-01

    This analysis presents the national energy balances from the national energy accounting. The first part presents the accounting analysis on the electric power consumption and production in France. The second part deals with the global energy accounting, for the energy sources and utilization, together. From these analysis the authors show how the global energy efficiency of production and utilization is possible. Solutions allowing the reduction of the non renewable energies consumption and solution for the nuclear power phaseout are also proposed. (A.L.B.)

  16. Exploring the free energy landscape: from dynamics to networks and back.

    Directory of Open Access Journals (Sweden)

    Diego Prada-Gracia

    2009-06-01

    Full Text Available Knowledge of the Free Energy Landscape topology is the essential key to understanding many biochemical processes. The determination of the conformers of a protein and their basins of attraction takes a central role for studying molecular isomerization reactions. In this work, we present a novel framework to unveil the features of a Free Energy Landscape answering questions such as how many meta-stable conformers there are, what the hierarchical relationship among them is, or what the structure and kinetics of the transition paths are. Exploring the landscape by molecular dynamics simulations, the microscopic data of the trajectory are encoded into a Conformational Markov Network. The structure of this graph reveals the regions of the conformational space corresponding to the basins of attraction. In addition, handling the Conformational Markov Network, relevant kinetic magnitudes as dwell times and rate constants, or hierarchical relationships among basins, completes the global picture of the landscape. We show the power of the analysis studying a toy model of a funnel-like potential and computing efficiently the conformers of a short peptide, dialanine, paving the way to a systematic study of the Free Energy Landscape in large peptides.

  17. Deciphering hierarchical features in the energy landscape of adenylate kinase folding/unfolding

    Science.gov (United States)

    Taylor, J. Nicholas; Pirchi, Menahem; Haran, Gilad; Komatsuzaki, Tamiki

    2018-03-01

    Hierarchical features of the energy landscape of the folding/unfolding behavior of adenylate kinase, including its dependence on denaturant concentration, are elucidated in terms of single-molecule fluorescence resonance energy transfer (smFRET) measurements in which the proteins are encapsulated in a lipid vesicle. The core in constructing the energy landscape from single-molecule time-series across different denaturant concentrations is the application of rate-distortion theory (RDT), which naturally considers the effects of measurement noise and sampling error, in combination with change-point detection and the quantification of the FRET efficiency-dependent photobleaching behavior. Energy landscapes are constructed as a function of observation time scale, revealing multiple partially folded conformations at small time scales that are situated in a superbasin. As the time scale increases, these denatured states merge into a single basin, demonstrating the coarse-graining of the energy landscape as observation time increases. Because the photobleaching time scale is dependent on the conformational state of the protein, possible nonequilibrium features are discussed, and a statistical test for violation of the detailed balance condition is developed based on the state sequences arising from the RDT framework.

  18. Direct design of an energy landscape with bistable DNA origami mechanisms.

    Science.gov (United States)

    Zhou, Lifeng; Marras, Alexander E; Su, Hai-Jun; Castro, Carlos E

    2015-03-11

    Structural DNA nanotechnology provides a feasible technique for the design and fabrication of complex geometries even exhibiting controllable dynamic behavior. Recently we have demonstrated the possibility of implementing macroscopic engineering design approaches to construct DNA origami mechanisms (DOM) with programmable motion and tunable flexibility. Here, we implement the design of compliant DNA origami mechanisms to extend from prescribing motion to prescribing an energy landscape. Compliant mechanisms facilitate motion via deformation of components with tunable stiffness resulting in well-defined mechanical energy stored in the structure. We design, fabricate, and characterize a DNA origami nanostructure with an energy landscape defined by two stable states (local energy minima) separated by a designed energy barrier. This nanostructure is a four-bar bistable mechanism with two undeformed states. Traversing between those states requires deformation, and hence mechanical energy storage, in a compliant arm of the linkage. The energy barrier for switching between two states was obtained from the conformational distribution based on a Boltzmann probability function and closely follows a predictive mechanical model. Furthermore, we demonstrated the ability to actuate the mechanism into one stable state via additional DNA inputs and then release the actuation via DNA strand displacement. This controllable multistate system establishes a foundation for direct design of energy landscapes that regulate conformational dynamics similar to biomolecular complexes.

  19. Free-energy landscape of protein oligomerization from atomistic simulations

    Science.gov (United States)

    Barducci, Alessandro; Bonomi, Massimiliano; Prakash, Meher K.; Parrinello, Michele

    2013-01-01

    In the realm of protein–protein interactions, the assembly process of homooligomers plays a fundamental role because the majority of proteins fall into this category. A comprehensive understanding of this multistep process requires the characterization of the driving molecular interactions and the transient intermediate species. The latter are often short-lived and thus remain elusive to most experimental investigations. Molecular simulations provide a unique tool to shed light onto these complex processes complementing experimental data. Here we combine advanced sampling techniques, such as metadynamics and parallel tempering, to characterize the oligomerization landscape of fibritin foldon domain. This system is an evolutionarily optimized trimerization motif that represents an ideal model for experimental and computational mechanistic studies. Our results are fully consistent with previous experimental nuclear magnetic resonance and kinetic data, but they provide a unique insight into fibritin foldon assembly. In particular, our simulations unveil the role of nonspecific interactions and suggest that an interplay between thermodynamic bias toward native structure and residual conformational disorder may provide a kinetic advantage. PMID:24248370

  20. Designing sustainable energy landscapes : concepts, principles and procedures

    NARCIS (Netherlands)

    Stremke, S.

    2010-01-01

    The depletion of fossil fuels, in combination with climate change, necessitates a transition to sustainable energy systems. Such systems are characterized by a decreased energy demand and an increase in the use of renewables. The objective of this dissertation is to advance the planning and design

  1. Enhanced conformational sampling to visualize a free-energy landscape of protein complex formation.

    Science.gov (United States)

    Iida, Shinji; Nakamura, Haruki; Higo, Junichi

    2016-06-15

    We introduce various, recently developed, generalized ensemble methods, which are useful to sample various molecular configurations emerging in the process of protein-protein or protein-ligand binding. The methods introduced here are those that have been or will be applied to biomolecular binding, where the biomolecules are treated as flexible molecules expressed by an all-atom model in an explicit solvent. Sampling produces an ensemble of conformations (snapshots) that are thermodynamically probable at room temperature. Then, projection of those conformations to an abstract low-dimensional space generates a free-energy landscape. As an example, we show a landscape of homo-dimer formation of an endothelin-1-like molecule computed using a generalized ensemble method. The lowest free-energy cluster at room temperature coincided precisely with the experimentally determined complex structure. Two minor clusters were also found in the landscape, which were largely different from the native complex form. Although those clusters were isolated at room temperature, with rising temperature a pathway emerged linking the lowest and second-lowest free-energy clusters, and a further temperature increment connected all the clusters. This exemplifies that the generalized ensemble method is a powerful tool for computing the free-energy landscape, by which one can discuss the thermodynamic stability of clusters and the temperature dependence of the cluster networks. © 2016 The Author(s).

  2. Relaxation height in energy landscapes : an application to multiple metastable states

    NARCIS (Netherlands)

    Cirillo, E.N.M.; Nardi, F.R.

    2012-01-01

    The study of systems with multiple (not necessarily degenerate) metastable states presents subtle difficulties from the mathematical point of view related to the variational problem that has to be solved in these cases. We introduce the notion of relaxation height in a general energy landscape and

  3. Probing the Free Energy Landscape of the FBP28 WW Domain Using Multiple Techniques

    NARCIS (Netherlands)

    Periole, Xavier; Allen, Lucy R.; Tamiola, Kamil; Mark, Alan E.; Paci, Emanuele

    The free-energy landscape of a small protein, the FBP 28 WW domain, has been explored using molecular dynamics (MD) simulations with alternative descriptions of the molecule. The molecular models used range from coarse-grained to all-atom with either an implicit or explicit treatment of the solvent.

  4. Conjugate gradient filtering of instantaneous normal modes, saddles on the energy landscape, and diffusion in liquids.

    Science.gov (United States)

    Chowdhary, J; Keyes, T

    2002-02-01

    Instantaneous normal modes (INM's) are calculated during a conjugate-gradient (CG) descent of the potential energy landscape, starting from an equilibrium configuration of a liquid or crystal. A small number (approximately equal to 4) of CG steps removes all the Im-omega modes in the crystal and leaves the liquid with diffusive Im-omega which accurately represent the self-diffusion constant D. Conjugate gradient filtering appears to be a promising method, applicable to any system, of obtaining diffusive modes and facilitating INM theory of D. The relation of the CG-step dependent INM quantities to the landscape and its saddles is discussed.

  5. The relative importance of physical and biological energy in landscape evolution

    Science.gov (United States)

    Turowski, J. M.; Schwanghart, W.

    2017-12-01

    Landscapes are formed by the interplay of uplift and geomorphic processes, including interacting and competing physical and biological processes. For example, roots re-inforce soil and thereby stabilize hillslopes and the canopy cover of the forest may mediate the impact of precipitation. Furthermore, plants and animals act as geomorphic agents, directly altering landscape response and dynamics by their actions: tree roots may crack rocks, thus changing subsurface water flows and exposing fresh material for denudation; fungi excrete acids that accelerate rates of chemical weathering, and burrowing animals displace soil and rocks while digging holes for shelter or in search of food. Energetically, landscapes can be viewed as open systems in which topography stores potential energy above a base level. Tectonic processes add energy to the system by uplift and mechanically altering rock properties. Especially in unvegetated regions, erosion and transport by wind can be an important geomorphic process. Advection of atmospheric moisture in high altitudes provides potential energy that is converted by water fluxes through catchments. At the same time, the conversion of solar energy through atmospheric and biological processes drives primary production of living organisms. If we accept that biota influence geomorphic processes, then what is their energetic contribution to landscape evolution relative to physical processes? Using two case studies, we demonstrate that all components of energy input are negligible apart from biological production, quantified by net primary productivity (NPP) and potential energy conversion by water that is placed high up in the landscape as rainfall and leaves it as runoff. Assuming that the former is representative for biological energy and the latter for physical energy, we propose that the ratio of these two values can be used as a proxy for the relative importance of biological and physical processes in landscape evolution. All necessary

  6. The Landscape of Renewable Energies in Europe in 2030

    International Nuclear Information System (INIS)

    Cruciani, Michel

    2017-06-01

    The study analyses the European rules designed to promote renewable energy, highlighting their innovations and the difficulties they will raise. The study highlights the consequences of some of the measures envisaged and pays particular attention to the electricity market. On 30 November 2016, the European Commission issued a new set of proposals, the 'Clean Energy Package', covering a wide spectrum of activities. This study analyses the provisions of this package which aim at improving energy efficiency by 30% and giving renewable energy a share of 27% of consumption by 2030. In 2014, Member States had called for these objectives to be assessed for the entire European Union. Nevertheless the Commission wishes to obtain a mandate to check that each State makes an honest contribution to the collective effort. The study stresses that the 30% target for energy efficiency weakens the role of the CO_2 market. The simulations reveal that this weakness will benefit coal, which keeps in 2030 a higher share than it would have occupied with a target of 27%, whereas natural gas is penalized by a low CO_2 price. It also appears that by remaining too low, the price of CO_2 will discourage certain investments in favour of renewable energies that would have naturally emerged with a high price. Therefore it will be necessary to roll out costly public policies to trigger these investments, so that the share of these energies totals 27% by 2030. The simulations also show that the renewable energy target will be largely achieved through very rapid growth of wind and solar power. The proposals of 30 November 2016 hence are drafted to encourage the development of these two sectors by reforming the electricity market so that it establishes a price that is remunerative and reduces the need for public aid, while clearly reflecting the burdens generated by the different actors. It seems unlikely that the Member States will accept such a profound market reform as the Commission envisages

  7. Global optimization of proteins using a dynamical lattice model: Ground states and energy landscapes

    OpenAIRE

    Dressel, F.; Kobe, S.

    2004-01-01

    A simple approach is proposed to investigate the protein structure. Using a low complexity model, a simple pairwise interaction and the concept of global optimization, we are able to calculate ground states of proteins, which are in agreement with experimental data. All possible model structures of small proteins are available below a certain energy threshold. The exact lowenergy landscapes for the trp cage protein (1L2Y) is presented showing the connectivity of all states and energy barriers.

  8. Energy Landscape of Pentapeptides in a Higher-Order (ϕ,ψ Conformational Subspace

    Directory of Open Access Journals (Sweden)

    Karim M. ElSawy

    2016-01-01

    Full Text Available The potential energy landscape of pentapeptides was mapped in a collective coordinate principal conformational subspace derived from principal component analysis of a nonredundant representative set of protein structures from the PDB. Three pentapeptide sequences that are known to be distinct in terms of their secondary structure characteristics, (Ala5, (Gly5, and Val.Asn.Thr.Phe.Val, were considered. Partitioning the landscapes into different energy valleys allowed for calculation of the relative propensities of the peptide secondary structures in a statistical mechanical framework. The distribution of the observed conformations of pentapeptide data showed good correspondence to the topology of the energy landscape of the (Ala5 sequence where, in accord with reported trends, the α-helix showed a predominant propensity at 298 K. The topography of the landscapes indicates that the stabilization of the α-helix in the (Ala5 sequence is enthalpic in nature while entropic factors are important for stabilization of the β-sheet in the Val.Asn.Thr.Phe.Val sequence. The results indicate that local interactions within small pentapeptide segments can lead to conformational preference of one secondary structure over the other where account of conformational entropy is important in order to reveal such preference. The method, therefore, can provide critical structural information for ab initio protein folding methods.

  9. Calculation of the Local Free Energy Landscape in the Restricted Region by the Modified Tomographic Method.

    Science.gov (United States)

    Chen, Changjun

    2016-03-31

    The free energy landscape is the most important information in the study of the reaction mechanisms of the molecules. However, it is difficult to calculate. In a large collective variable space, a molecule must take a long time to obtain the sufficient sampling during the simulation. To save the calculation quantity, decreasing the sampling region and constructing the local free energy landscape is required in practice. However, the restricted region in the collective variable space may have an irregular shape. Simply restricting one or more collective variables of the molecule cannot satisfy the requirement. In this paper, we propose a modified tomographic method to perform the simulation. First, it divides the restricted region by some hyperplanes and connects the centers of hyperplanes together by a curve. Second, it forces the molecule to sample on the curve and the hyperplanes in the simulation and calculates the free energy data on them. Finally, all the free energy data are combined together to form the local free energy landscape. Without consideration of the area outside the restricted region, this free energy calculation can be more efficient. By this method, one can further optimize the path quickly in the collective variable space.

  10. Low Energy Supersymmetry from the Heterotic String Landscape

    CERN Document Server

    Lebedev, O; Raby, S; Ramos-Sanchez, S; Ratz, M; Vaudrevange, P K S; Wingerter, A; Lebedev, Oleg; Nilles, Hans-Peter; Raby, Stuart; Ramos-Sanchez, Saul; Ratz, Michael; Vaudrevange, Patrick K. S.; Wingerter, Akin

    2007-01-01

    We study possible correlations between properties of the observable and hidden sectors in heterotic string theory. Specifically, we analyze the case of the Z6-II orbifold compactification which produces a significant number of models with the spectrum of the supersymmetric standard model. We find that requiring realistic features does affect the hidden sector such that hidden sector gauge group factors SU(4) and SO(8) are favoured. In the context of gaugino condensation, this implies low energy supersymmetry breaking.

  11. Landscape management for sustainable supplies of bio energy feedstock and enhanced soil quality

    International Nuclear Information System (INIS)

    Douglas, K.; Muth, D.

    2013-01-01

    Agriculture can simultaneously address global food, feed, fiber, and energy challenges provided our soil, water, and air resources are not compromised in doing so. Our objective is to present a landscape management concept as an approach for integrating multiple bio energy feedstock sources into current crop production systems. This is done to show how multiple, increasing global challenges can be met in a sustainable manner. We discuss how collaborative research among Usda-Agricultural Research Service (ARS), US Department of Energy (DOE) Idaho National Laboratory (INL), several university extension and research partners, and industry representatives [known as the Renewable Energy Assessment Project (Reap) team] has led to the development of computer-based decision aids for guiding sustainable bio energy feedstock production. The decision aids, known initially as the Corn Stover Tool and more recently as the Landscape Environmental Assessment Framework (Leaf) are tools designed to recognize the importance of nature s diversity and can therefore be used to guide sustainable feedstock production without having negative impacts on critical ecosystem services. Using a 57 ha farm site in central Iowa, USA, we show how producer decisions regarding corn (Zea mays L.) stover harvest within the US Corn Belt can be made in a more sustainable manner. This example also supports Reap team conclusions that stover should not be harvested if average grain yields are less than 11 Mg ha-1 unless more balanced landscape management practices are implemented. The tools also illustrate the importance of sub-field management and site-specific stover harvest strategies

  12. Energy landscape reveals that the budding yeast cell cycle is a robust and adaptive multi-stage process.

    Directory of Open Access Journals (Sweden)

    Cheng Lv

    2015-03-01

    Full Text Available Quantitatively understanding the robustness, adaptivity and efficiency of cell cycle dynamics under the influence of noise is a fundamental but difficult question to answer for most eukaryotic organisms. Using a simplified budding yeast cell cycle model perturbed by intrinsic noise, we systematically explore these issues from an energy landscape point of view by constructing an energy landscape for the considered system based on large deviation theory. Analysis shows that the cell cycle trajectory is sharply confined by the ambient energy barrier, and the landscape along this trajectory exhibits a generally flat shape. We explain the evolution of the system on this flat path by incorporating its non-gradient nature. Furthermore, we illustrate how this global landscape changes in response to external signals, observing a nice transformation of the landscapes as the excitable system approaches a limit cycle system when nutrients are sufficient, as well as the formation of additional energy wells when the DNA replication checkpoint is activated. By taking into account the finite volume effect, we find additional pits along the flat cycle path in the landscape associated with the checkpoint mechanism of the cell cycle. The difference between the landscapes induced by intrinsic and extrinsic noise is also discussed. In our opinion, this meticulous structure of the energy landscape for our simplified model is of general interest to other cell cycle dynamics, and the proposed methods can be applied to study similar biological systems.

  13. Modeling energy fluxes in heterogeneous landscapes employing a mosaic approach

    Science.gov (United States)

    Klein, Christian; Thieme, Christoph; Priesack, Eckart

    2015-04-01

    Recent studies show that uncertainties in regional and global climate and weather simulations are partly due to inadequate descriptions of the energy flux exchanges between the land surface and the atmosphere. One major shortcoming is the limitation of the grid-cell resolution, which is recommended to be about at least 3x3 km² in most models due to limitations in the model physics. To represent each individual grid cell most models select one dominant soil type and one dominant land use type. This resolution, however, is often too coarse in regions where the spatial diversity of soil and land use types are high, e.g. in Central Europe. An elegant method to avoid the shortcoming of grid cell resolution is the so called mosaic approach. This approach is part of the recently developed ecosystem model framework Expert-N 5.0. The aim of this study was to analyze the impact of the characteristics of two managed fields, planted with winter wheat and potato, on the near surface soil moistures and on the near surface energy flux exchanges of the soil-plant-atmosphere interface. The simulated energy fluxes were compared with eddy flux tower measurements between the respective fields at the research farm Scheyern, North-West of Munich, Germany. To perform these simulations, we coupled the ecosystem model Expert-N 5.0 to an analytical footprint model. The coupled model system has the ability to calculate the mixing ratio of the surface energy fluxes at a given point within one grid cell (in this case at the flux tower between the two fields). This approach accounts for the differences of the two soil types, of land use managements, and of canopy properties due to footprint size dynamics. Our preliminary simulation results show that a mosaic approach can improve modeling and analyzing energy fluxes when the land surface is heterogeneous. In this case our applied method is a promising approach to extend weather and climate models on the regional and on the global scale.

  14. Energy landscape of defects in body-centered cubic metals

    International Nuclear Information System (INIS)

    Alexander, Rebecca

    2016-01-01

    The structural materials in nuclear reactors are subjected to severe irradiation conditions, leading to changes in their mechanical properties. The aging of these materials raises important issues such as those related to the safety of existing plants and future reactors. In many cases, materials with body-centered cubic bcc crystal structure are used with iron, tungsten, vanadium and tantalum as base metal. Collisions between irradiating particles and atoms constituting materials generate point defects whose migration leads to the formation of clusters responsible for aging. In this thesis, we studied the energetic properties of point defects in the bcc metals mentioned above at the atomic scale. Modeling point defects at the atomic scale can be achieved with different methods that differ only in the quality of the description of the interaction between atoms. Studies using accurate atomic interactions such ab initio calculations are computationally costly making it impossible to directly study clusters of large sizes. The modeling of atomic interactions using semi-empirical potentials reduces the reliability of predictive calculations but allow calculations for large-sized clusters. In this thesis we have developed a unique energy model for dislocation loops as well as for three-dimensional interstitial cluster of type C15. The resulting model has no size limit and can be set entirely by ab initio calculations. To test its robustness for large sizes of clusters we also set this model with semi-empirical potentials calculations and compared the predictions of the model to atomic simulations. With our development we have determined: (i) The relative stability of interstitial dislocation loops according to their Burgers vectors. (ii) The stability of the clusters C15 compared to the type of cluster loop. We showed that the C15 type clusters are more stable when they involve less than 41 interstitials in iron. (iii) In Ta we were able to show the same stability till

  15. Renewable energy policy and landscape management in Andalusia, Spain: The facts

    International Nuclear Information System (INIS)

    Prados, Maria-Jose

    2010-01-01

    Renewable energy has developed spectacularly in Spain since the European Union started a process of energy policy reform. A review of Spanish State legislation on renewable energies confirms that the success in installing renewable energy is attributable to public aid. Andalusia is one of the autonomous communities, which has simultaneously developed the legal framework and very successfully implemented the introduction of renewable power. When implementing the central government's policy, the Andalusian regional government prioritised increases in both surface cover by wind and solar plants (thermal and photovoltaic energy) and in the number of companies involved. However, this development of renewable energies took place without any proper integration into regional spatial and landscape planning. This paper explores renewable power implementation in Andalusia through regulatory measures put in place over the last decade to develop renewable energy systems and the way they can be managed alongside planning issues. The location of large-scale renewable plants has had consequences for territory in the socio-political context of renewable energy promotion. The main findings focus on renewable energy plant sprawl throughout rural areas in Andalusia with no clear effect on landscape management and no firm backing from the local population.

  16. Free Energy Landscapes of Alanine Oligopeptides in Rigid-Body and Hybrid Water Models.

    Science.gov (United States)

    Nayar, Divya; Chakravarty, Charusita

    2015-08-27

    Replica exchange molecular dynamics is used to study the effect of different rigid-body (mTIP3P, TIP4P, SPC/E) and hybrid (H1.56, H3.00) water models on the conformational free energy landscape of the alanine oligopeptides (acAnme and acA5nme), in conjunction with the CHARMM22 force field. The free energy landscape is mapped out as a function of the Ramachandran angles. In addition, various secondary structure metrics, solvation shell properties, and the number of peptide-solvent hydrogen bonds are monitored. Alanine dipeptide is found to have similar free energy landscapes in different solvent models, an insensitivity which may be due to the absence of possibilities for forming i-(i + 4) or i-(i + 3) intrapeptide hydrogen bonds. The pentapeptide, acA5nme, where there are three intrapeptide backbone hydrogen bonds, shows a conformational free energy landscape with a much greater degree of sensitivity to the choice of solvent model, though the three rigid-body water models differ only quantitatively. The pentapeptide prefers nonhelical, non-native PPII and β-sheet populations as the solvent is changed from SPC/E to the less tetrahedral liquid (H1.56) to an LJ-like liquid (H3.00). The pentapeptide conformational order metrics indicate a preference for open, solvent-exposed, non-native structures in hybrid solvent models at all temperatures of study. The possible correlations between the properties of solvent models and secondary structure preferences of alanine oligopeptides are discussed, and the competition between intrapeptide, peptide-solvent, and solvent-solvent hydrogen bonding is shown to be crucial in the relative free energies of different conformers.

  17. Energy landscape scheme for an intuitive understanding of complex domain dynamics in ferroelectric thin films.

    Science.gov (United States)

    Kim, Tae Heon; Yoon, Jong-Gul; Baek, Seung Hyub; Park, Woong-kyu; Yang, Sang Mo; Yup Jang, Seung; Min, Taeyuun; Chung, Jin-Seok; Eom, Chang-Beom; Noh, Tae Won

    2015-07-01

    Fundamental understanding of domain dynamics in ferroic materials has been a longstanding issue because of its relevance to many systems and to the design of nanoscale domain-wall devices. Despite many theoretical and experimental studies, a full understanding of domain dynamics still remains incomplete, partly due to complex interactions between domain-walls and disorder. We report domain-shape-preserving deterministic domain-wall motion, which directly confirms microscopic return point memory, by observing domain-wall breathing motion in ferroelectric BiFeO3 thin film using stroboscopic piezoresponse force microscopy. Spatial energy landscape that provides new insights into domain dynamics is also mapped based on the breathing motion of domain walls. The evolution of complex domain structure can be understood by the process of occupying the lowest available energy states of polarization in the energy landscape which is determined by defect-induced internal fields. Our result highlights a pathway for the novel design of ferroelectric domain-wall devices through the engineering of energy landscape using defect-induced internal fields such as flexoelectric fields.

  18. Energy landscape scheme for an intuitive understanding of complex domain dynamics in ferroelectric thin films

    Science.gov (United States)

    Heon Kim, Tae; Yoon, Jong-Gul; Hyub Baek, Seung; Park, Woong-Kyu; Mo Yang, Sang; Yup Jang, Seung; Min, Taeyuun; Chung, Jin-Seok; Eom, Chang-Beom; Won Noh, Tae

    2015-07-01

    Fundamental understanding of domain dynamics in ferroic materials has been a longstanding issue because of its relevance to many systems and to the design of nanoscale domain-wall devices. Despite many theoretical and experimental studies, a full understanding of domain dynamics still remains incomplete, partly due to complex interactions between domain-walls and disorder. We report domain-shape-preserving deterministic domain-wall motion, which directly confirms microscopic return point memory, by observing domain-wall breathing motion in ferroelectric BiFeO3 thin film using stroboscopic piezoresponse force microscopy. Spatial energy landscape that provides new insights into domain dynamics is also mapped based on the breathing motion of domain walls. The evolution of complex domain structure can be understood by the process of occupying the lowest available energy states of polarization in the energy landscape which is determined by defect-induced internal fields. Our result highlights a pathway for the novel design of ferroelectric domain-wall devices through the engineering of energy landscape using defect-induced internal fields such as flexoelectric fields.

  19. Relationship between energy systems and landscapes. Guidelines and tools for design and management

    Directory of Open Access Journals (Sweden)

    Elisabetta Ginelli

    2014-10-01

    Full Text Available Landscapes undergoing conservation, valorisation, management and reconstruction policies, become a fundamental factor for the local/global development of natural, cultural, human and social potentials of territories. With the contribution of technological design culture, the research, having a strong multidisciplinary character, focuses on managing the relationship between energy systems and landscapes with the general aim of subverting and transforming apparent conflicts in synergies, in order to overcome a sectorial and segmented approach barely based on energy performances. Through the introduction of a complex multidimensional methodology of analysis and evaluation the goal of this work, is to develop standards of acceptability, meta-design criteria and guidelines for design, intro- ducing a methodology for multidimen- sional complex analysis and evaluation, to support Public Authorities.

  20. The mechanisms for filling carbon nanotubes with molten salts: carbon nanotubes as energy landscape filters

    International Nuclear Information System (INIS)

    Bishop, Clare L; Wilson, Mark

    2009-01-01

    The mechanisms for filling carbon nanotubes with molten salts are investigated using molecular dynamics computer simulation. Inorganic nanotubular structures, whose morphologies can be rationalized in terms of the folding, or the removal of sections from, planes of square nets are found to form. The formation mechanisms are found to follow a 'chain-by-chain' motif in which the structures build systematically from charge neutral M-X-M-Xc chains. The formation mechanisms are rationalized in terms of the ion-ion interactions (intra-chain and inter-chain terms). In addition, the mechanisms of filling are discussed in terms of a 'hopping' between basins on the underlying energy landscape. The role of the carbon nanotube as an energy landscape filter is discussed.

  1. Frustration in the energy landscapes of multidomain protein misfolding.

    Science.gov (United States)

    Zheng, Weihua; Schafer, Nicholas P; Wolynes, Peter G

    2013-01-29

    Frustration from strong interdomain interactions can make misfolding a more severe problem in multidomain proteins than in single-domain proteins. On the basis of bioinformatic surveys, it has been suggested that lowering the sequence identity between neighboring domains is one of nature's solutions to the multidomain misfolding problem. We investigate folding of multidomain proteins using the associative-memory, water-mediated, structure and energy model (AWSEM), a predictive coarse-grained protein force field. We find that reducing sequence identity not only decreases the formation of domain-swapped contacts but also decreases the formation of strong self-recognition contacts between β-strands with high hydrophobic content. The ensembles of misfolded structures that result from forming these amyloid-like interactions are energetically disfavored compared with the native state, but entropically favored. Therefore, these ensembles are more stable than the native ensemble under denaturing conditions, such as high temperature. Domain-swapped contacts compete with self-recognition contacts in forming various trapped states, and point mutations can shift the balance between the two types of interaction. We predict that multidomain proteins that lack these specific strong interdomain interactions should fold reliably.

  2. Autonomously folding protein fragments reveal differences in the energy landscapes of homologous RNases H.

    Directory of Open Access Journals (Sweden)

    Laura E Rosen

    Full Text Available An important approach to understanding how a protein sequence encodes its energy landscape is to compare proteins with different sequences that fold to the same general native structure. In this work, we compare E. coli and T. thermophilus homologs of the protein RNase H. Using protein fragments, we create equilibrium mimics of two different potential partially-folded intermediates (I(core and I(core+1 hypothesized to be present on the energy landscapes of these two proteins. We observe that both T. thermophilus RNase H (ttRNH fragments are folded and have distinct stabilities, indicating that both regions are capable of autonomous folding and that both intermediates are present as local minima on the ttRNH energy landscape. In contrast, the two E. coli RNase H (ecRNH fragments have very similar stabilities, suggesting that the presence of additional residues in the I(core+1 fragment does not affect the folding or structure as compared to I(core. NMR experiments provide additional evidence that only the I(core intermediate is populated by ecRNH. This is one of the biggest differences that has been observed between the energy landscapes of these two proteins. Additionally, we used a FRET experiment in the background of full-length ttRNH to specifically monitor the formation of the I(core+1 intermediate. We determine that the ttRNH I(core+1 intermediate is likely the intermediate populated prior to the rate-limiting barrier to global folding, in contrast to E. coli RNase H for which I(core is the folding intermediate. This result provides new insight into the nature of the rate-limiting barrier for the folding of RNase H.

  3. Multifunctional energy landscape for a DNA G-quadruplex: An evolved molecular switch

    Science.gov (United States)

    Cragnolini, Tristan; Chakraborty, Debayan; Šponer, Jiří; Derreumaux, Philippe; Pasquali, Samuela; Wales, David J.

    2017-10-01

    We explore the energy landscape for a four-fold telomere repeat, obtaining interconversion pathways between six experimentally characterised G-quadruplex topologies. The results reveal a multi-funnel system, with a variety of intermediate configurations and misfolded states. This organisation is identified with the intrinsically multi-functional nature of the system, suggesting a new paradigm for the classification of such biomolecules and clarifying issues regarding apparently conflicting experimental results.

  4. A new approach to quantify semiochemical effects on insects based on energy landscapes.

    Directory of Open Access Journals (Sweden)

    Rory P Wilson

    Full Text Available Our ability to document insect preference for semiochemicals is pivotal in pest control as these agents can improve monitoring and be deployed within integrated pest management programmes for more efficacious control of pest species. However, methods used to date have drawbacks that limit their utility. We present and test a new concept for determining insect motivation to move towards, or away from, semiochemicals by noting direction and speed of movement as animals work against a defined energy landscape (environmentally dependent variation in the cost of transport requiring different powers to negotiate. We conducted trials with the pine weevils Hylobius abietis and peach-potato aphids Myzus persicae exposed to various attractants and repellents and placed so that they either moved up defined slopes against gravity or had to travel over variously rough surfaces.Linear Mixed Models demonstrated clear reductions in travel speed by insects moving along increasingly energetically taxing energy landscapes but also that responses varied according to different semiochemicals, thus highlighting the value of energy landscapes as a new concept to help measure insect motivation to access or avoid different attractants or repellents across individuals.New sensitive, detailed indicators of insect motivation derived from this approach should prove important in pest control across the world.

  5. Energy landscape of all-atom protein-protein interactions revealed by multiscale enhanced sampling.

    Directory of Open Access Journals (Sweden)

    Kei Moritsugu

    2014-10-01

    Full Text Available Protein-protein interactions are regulated by a subtle balance of complicated atomic interactions and solvation at the interface. To understand such an elusive phenomenon, it is necessary to thoroughly survey the large configurational space from the stable complex structure to the dissociated states using the all-atom model in explicit solvent and to delineate the energy landscape of protein-protein interactions. In this study, we carried out a multiscale enhanced sampling (MSES simulation of the formation of a barnase-barstar complex, which is a protein complex characterized by an extraordinary tight and fast binding, to determine the energy landscape of atomistic protein-protein interactions. The MSES adopts a multicopy and multiscale scheme to enable for the enhanced sampling of the all-atom model of large proteins including explicit solvent. During the 100-ns MSES simulation of the barnase-barstar system, we observed the association-dissociation processes of the atomistic protein complex in solution several times, which contained not only the native complex structure but also fully non-native configurations. The sampled distributions suggest that a large variety of non-native states went downhill to the stable complex structure, like a fast folding on a funnel-like potential. This funnel landscape is attributed to dominant configurations in the early stage of the association process characterized by near-native orientations, which will accelerate the native inter-molecular interactions. These configurations are guided mostly by the shape complementarity between barnase and barstar, and lead to the fast formation of the final complex structure along the downhill energy landscape.

  6. Monitoring Forest Change in Landscapes Under-Going Rapid Energy Development: Challenges and New Perspectives

    Directory of Open Access Journals (Sweden)

    Paul D. Pickell

    2014-07-01

    Full Text Available The accelerated development of energy resources around the world has substantially increased forest change related to oil and gas activities. In some cases, oil and gas activities are the primary catalyst of land-use change in forested landscapes. We discuss the challenges associated with characterizing ecological change related to energy resource development using North America as an exemplar. We synthesize the major impacts of energy development to forested ecosystems and offer new perspectives on how to detect and monitor anthropogenic disturbance during the Anthropocene. The disturbance of North American forests for energy development has resulted in persistent linear corridors, suppression of historical disturbance regimes, novel ecosystems, and the eradication of ecological memory. Characterizing anthropogenic disturbances using conventional patch-based disturbance measures will tend to underestimate the ecological impacts of energy development. Suitable indicators of anthropogenic impacts in forests should be derived from the integration of multi-scalar Earth observations. Relating these indicators to ecosystem condition will be a capstone in the progress toward monitoring forest change in landscapes undergoing rapid energy development.

  7. The potential energy landscape in the Lennard-Jones binary mixture model

    International Nuclear Information System (INIS)

    Sampoli, M; Benassi, P; Eramo, R; Angelani, L; Ruocco, G

    2003-01-01

    The potential energy landscape in the Kob-Andersen Lennard-Jones binary mixture model has been studied carefully from the liquid down to the supercooled regime, from T = 2 down to 0.46. One thousand independent configurations along the time evolution locus have been examined at each temperature investigated. From the starting configuration, we searched for the nearest saddle (or quasi-saddle) and minimum of the potential energy. The vibrational densities of states for the starting and the two derived configurations have been evaluated. Besides the number of negative eigenvalues of the saddles other quantities show some signature of the approach of the dynamical arrest temperature

  8. Energy Landscape and Pathways for Transitions between Watson-Crick and Hoogsteen Base Pairing in DNA.

    Science.gov (United States)

    Chakraborty, Debayan; Wales, David J

    2018-01-04

    The recent discovery that Hoogsteen (HG) base pairs are widespread in DNA across diverse sequences and positional contexts could have important implications for understanding DNA replication and DNA-protein recognition. While evidence is emerging that the Hoogsteen conformation could be a thermodynamically accessible conformation of the DNA duplex and provide a means to expand its functionality, relatively little is known about the molecular mechanism underlying the Watson-Crick (WC) to HG transition. In this Perspective, we describe pathways and kinetics for this transition at an atomic level of detail, using the energy landscape perspective. We show that competition between the duplex conformations results in a double funnel landscape, which explains some recent experimental observations. The interconversion pathways feature a number of intermediates, with a variable number of WC and HG base pairs. The relatively slow kinetics, with possible deviations from two-state behavior, suggest that this conformational switch is likely to be a challenging target for both simulation and experiment.

  9. Simple solvable energy-landscape model that shows a thermodynamic phase transition and a glass transition.

    Science.gov (United States)

    Naumis, Gerardo G

    2012-06-01

    When a liquid melt is cooled, a glass or phase transition can be obtained depending on the cooling rate. Yet, this behavior has not been clearly captured in energy-landscape models. Here, a model is provided in which two key ingredients are considered in the landscape, metastable states and their multiplicity. Metastable states are considered as in two level system models. However, their multiplicity and topology allows a phase transition in the thermodynamic limit for slow cooling, while a transition to the glass is obtained for fast cooling. By solving the corresponding master equation, the minimal speed of cooling required to produce the glass is obtained as a function of the distribution of metastable states.

  10. Energy landscapes shape microbial communities in hydrothermal systems on the Arctic Mid-Ocean Ridge.

    Science.gov (United States)

    Dahle, Håkon; Økland, Ingeborg; Thorseth, Ingunn H; Pederesen, Rolf B; Steen, Ida H

    2015-07-01

    Methods developed in geochemical modelling combined with recent advances in molecular microbial ecology provide new opportunities to explore how microbial communities are shaped by their chemical surroundings. Here, we present a framework for analyses of how chemical energy availability shape chemotrophic microbial communities in hydrothermal systems through an investigation of two geochemically different basalt-hosted hydrothermal systems on the Arctic Mid-Ocean Ridge: the Soria Moria Vent field (SMVF) and the Loki's Castle Vent Field (LCVF). Chemical energy landscapes were evaluated through modelling of the Gibbs energy from selected redox reactions under different mixing ratios between seawater and hydrothermal fluids. Our models indicate that the sediment-influenced LCVF has a much higher potential for both anaerobic and aerobic methane oxidation, as well as aerobic ammonium and hydrogen oxidation, than the SMVF. The modelled energy landscapes were used to develop microbial community composition models, which were compared with community compositions in environmental samples inside or on the exterior of hydrothermal chimneys, as assessed by pyrosequencing of partial 16S rRNA genes. We show that modelled microbial communities based solely on thermodynamic considerations can have a high predictive power and provide a framework for analyses of the link between energy availability and microbial community composition.

  11. An energy landscape based approach for studying supercooled liquid and glassy thin films

    Science.gov (United States)

    Shah, Pooja; Mittal, Jeetain; Truskett, Thomas M.

    2004-03-01

    Materials in confined spaces are important in science and technology. Examples include biological fluids in membranes, liquids trapped in porous rocks, and thin-film materials used in high-resolution patterning technologies. However, few reliable rules exist to predict how the properties of materials will be affected by thin-film confinement. We have recently shown that the potential energy landscape formalism can be used to study, by both theory [1] and simulation [2], how the behavior of thin-film materials depends on sample dimensions and film-substrate interactions. Our landscape-based mean-field theory [1] can be used to study both the thermodynamic properties and the ideal glass transition of thin films. It predicts that, in the case of neutral or repulsive walls, the ideal glass transition temperature is lowered by decreasing film thickness. This is in qualitative agreement with experimental trends for the kinetic glass transition in confined fluids. Landscape-based approaches are also valuable for understanding the structural and mechanical properties of thin-film glasses. We demonstrate how the concept of an "equation of state of the energy landscape" [3] can be generalized to thin films [1, 2], where it gives insights into potential molecular mechanisms of tensile strength. [1] T. M. Truskett and V. Ganesan, J. Chem. Phys. 119, 1897-1900(2003); J. Mittal, P. Shah and T. M. Truskett, to be submitted to Langmuir. [2] P. Shah and T. M. Truskett, to be submitted to J. Phys. Chem. B. [3] S. Sastry, P. G. Debenedetti and F. H. Stillinger, Phys. Rev. E 56, 5533 (1997)

  12. Free energy landscapes of electron transfer system in dipolar environment below and above the rotational freezing temperature

    International Nuclear Information System (INIS)

    Suzuki, Yohichi; Tanimura, Yoshitaka

    2007-01-01

    Electron transfer reaction in a polar solvent is modeled by a solute dipole surrounded by dipolar molecules with simple rotational dynamics posted on the three-dimensional distorted lattice sites. The interaction energy between the solute and solvent dipoles as a reaction coordinate is adopted and free energy landscapes are calculated by generating all possible states for a 26 dipolar system and by employing Wang-Landau sampling algorithm for a 92 dipolar system. For temperatures higher than the energy scale of dipole-dipole interactions, the free energy landscapes for the small reaction coordinate region have quadratic shape as predicted by Marcus [Rev. Mod. Phys. 65, 599 (1993)] whereas for the large reaction coordinate region, the landscapes exhibit a nonquadratic shape. When the temperature drops, small notched structures appear on the free energy profiles because of the frustrated interactions among dipoles. The formation of notched structure is analyzed with statistical approach and it is shown that the amplitude of notched structure depend upon the segment size of the reaction coordinate and is characterized by the interaction energy among the dipoles. Using simulated free energy landscapes, the authors calculate the reaction rates as a function of the energy gap for various temperatures. At high temperature, the reactions rates follow a bell shaped (inverted parabolic) energy gap law in the small energy gap regions, while it becomes steeper than the parabolic shape in a large energy gap regions due to the nonquadratic shape of the free energy landscape. The peak position of parabola also changes as the function of temperature. At low temperature, the profile of the reaction rates is no longer smooth because of the many local minima of the free energy landscape

  13. Potential energy landscape and robustness of a gene regulatory network: toggle switch.

    Directory of Open Access Journals (Sweden)

    Keun-Young Kim

    2007-03-01

    Full Text Available Finding a multidimensional potential landscape is the key for addressing important global issues, such as the robustness of cellular networks. We have uncovered the underlying potential energy landscape of a simple gene regulatory network: a toggle switch. This was realized by explicitly constructing the steady state probability of the gene switch in the protein concentration space in the presence of the intrinsic statistical fluctuations due to the small number of proteins in the cell. We explored the global phase space for the system. We found that the protein synthesis rate and the unbinding rate of proteins to the gene were small relative to the protein degradation rate; the gene switch is monostable with only one stable basin of attraction. When both the protein synthesis rate and the unbinding rate of proteins to the gene are large compared with the protein degradation rate, two global basins of attraction emerge for a toggle switch. These basins correspond to the biologically stable functional states. The potential energy barrier between the two basins determines the time scale of conversion from one to the other. We found as the protein synthesis rate and protein unbinding rate to the gene relative to the protein degradation rate became larger, the potential energy barrier became larger. This also corresponded to systems with less noise or the fluctuations on the protein numbers. It leads to the robustness of the biological basins of the gene switches. The technique used here is general and can be applied to explore the potential energy landscape of the gene networks.

  14. The environmental benefits of cellulosic energy crops at a landscape scale

    International Nuclear Information System (INIS)

    Graham, R.L.; Liu, W.; English, B.C.

    1995-01-01

    The objective of this paper is to present a broad overview of the potential environmental impacts of biomass energy from energy crops--particularly the cellulosic energy crops current under development. For this discussion, the term energy crop refers to a crop grown primarily to create feedstock for either making biofuels such as ethanol or burning in a heat or electricity generation facility. Cellulosic energy crops are designed to be used in cellulose-based ethanol conversion processes (as opposed to starch or sugar-based ethanol conversion processes). As more cellulose can be produced per hectare of land than can sugar or starch, the cellulose-based ethanol conversion process is a more efficient sue of land for ethanol production. Assessing the environmental impacts of biomass energy from energy crops is complex because the environmental impact of using biomass for energy must be considered in the context of alternative energy options while the environmental impact of producing biomass from energy crops must be considered in the context of alternative land-uses. Using biomass-derived energy can reduce greenhouse gas emissions or increase them; growing biomass energy crops can enhance soil fertility or degrade it. Without knowing the context of the biomass energy, one can say little about its specific environmental impacts. The primary focus of this paper is an evaluation of the environmental impacts of growing cellulosic energy crops especially at the landscape or regional scale. However, to set the stage for this discussion, the authors begin by comparing the environmental advantages and disadvantages of biomass-derived energy relative to other energy alternatives such as coal, hydropower, nuclear power, oil/gasoline, natural gas and photovoltaics

  15. Role of Electrostatics in Protein-RNA Binding: The Global vs the Local Energy Landscape.

    Science.gov (United States)

    Ghaemi, Zhaleh; Guzman, Irisbel; Gnutt, David; Luthey-Schulten, Zaida; Gruebele, Martin

    2017-09-14

    U1A protein-stem loop 2 RNA association is a basic step in the assembly of the spliceosomal U1 small nuclear ribonucleoprotein. Long-range electrostatic interactions due to the positive charge of U1A are thought to provide high binding affinity for the negatively charged RNA. Short range interactions, such as hydrogen bonds and contacts between RNA bases and protein side chains, favor a specific binding site. Here, we propose that electrostatic interactions are as important as local contacts in biasing the protein-RNA energy landscape toward a specific binding site. We show by using molecular dynamics simulations that deletion of two long-range electrostatic interactions (K22Q and K50Q) leads to mutant-specific alternative RNA bound states. One of these states preserves short-range interactions with aromatic residues in the original binding site, while the other one does not. We test the computational prediction with experimental temperature-jump kinetics using a tryptophan probe in the U1A-RNA binding site. The two mutants show the distinct predicted kinetic behaviors. Thus, the stem loop 2 RNA has multiple binding sites on a rough RNA-protein binding landscape. We speculate that the rough protein-RNA binding landscape, when biased to different local minima by electrostatics, could be one way that protein-RNA interactions evolve toward new binding sites and novel function.

  16. Electrostatics, structure prediction, and the energy landscapes for protein folding and binding.

    Science.gov (United States)

    Tsai, Min-Yeh; Zheng, Weihua; Balamurugan, D; Schafer, Nicholas P; Kim, Bobby L; Cheung, Margaret S; Wolynes, Peter G

    2016-01-01

    While being long in range and therefore weakly specific, electrostatic interactions are able to modulate the stability and folding landscapes of some proteins. The relevance of electrostatic forces for steering the docking of proteins to each other is widely acknowledged, however, the role of electrostatics in establishing specifically funneled landscapes and their relevance for protein structure prediction are still not clear. By introducing Debye-Hückel potentials that mimic long-range electrostatic forces into the Associative memory, Water mediated, Structure, and Energy Model (AWSEM), a transferable protein model capable of predicting tertiary structures, we assess the effects of electrostatics on the landscapes of thirteen monomeric proteins and four dimers. For the monomers, we find that adding electrostatic interactions does not improve structure prediction. Simulations of ribosomal protein S6 show, however, that folding stability depends monotonically on electrostatic strength. The trend in predicted melting temperatures of the S6 variants agrees with experimental observations. Electrostatic effects can play a range of roles in binding. The binding of the protein complex KIX-pKID is largely assisted by electrostatic interactions, which provide direct charge-charge stabilization of the native state and contribute to the funneling of the binding landscape. In contrast, for several other proteins, including the DNA-binding protein FIS, electrostatics causes frustration in the DNA-binding region, which favors its binding with DNA but not with its protein partner. This study highlights the importance of long-range electrostatics in functional responses to problems where proteins interact with their charged partners, such as DNA, RNA, as well as membranes. © 2015 The Protein Society.

  17. Time Series Analysis of Energy Production and Associated Landscape Fragmentation in the Eagle Ford Shale Play

    Science.gov (United States)

    Pierre, Jon Paul; Young, Michael H.; Wolaver, Brad D.; Andrews, John R.; Breton, Caroline L.

    2017-11-01

    Spatio-temporal trends in infrastructure footprints, energy production, and landscape alteration were assessed for the Eagle Ford Shale of Texas. The period of analysis was over four 2-year periods (2006-2014). Analyses used high-resolution imagery, as well as pipeline data to map EF infrastructure. Landscape conditions from 2006 were used as baseline. Results indicate that infrastructure footprints varied from 94.5 km2 in 2008 to 225.0 km2 in 2014. By 2014, decreased land-use intensities (ratio of land alteration to energy production) were noted play-wide. Core-area alteration by period was highest (3331.6 km2) in 2008 at the onset of play development, and increased from 582.3 to 3913.9 km2 by 2014, though substantial revegetation of localized core areas was observed throughout the study (i.e., alteration improved in some areas and worsened in others). Land-use intensity in the eastern portion of the play was consistently lower than that in the western portion, while core alteration remained relatively constant east to west. Land alteration from pipeline construction was 65 km2 for all time periods, except in 2010 when alteration was recorded at 47 km2. Percent of total alteration from well-pad construction increased from 27.3% in 2008 to 71.5% in 2014. The average number of wells per pad across all 27 counties increased from 1.15 to 1.7. This study presents a framework for mapping landscape alteration from oil and gas infrastructure development. However, the framework could be applied to other energy development programs, such as wind or solar fields, or any other regional infrastructure development program.

  18. Free energy landscape and cooperatively rearranging region in a hard sphere glass

    Science.gov (United States)

    Yoshidome, Takashi; Yoshimori, Akira; Odagaki, Takashi

    2007-08-01

    Exploiting the density functional theory, we calculate the free energy landscape (FEL) of the hard sphere glass in three dimensions. From the FEL, we estimate the number of the particles in the cooperatively rearranging region (CRR). We find that the density dependence of the number of the particles in the CRR is expressed as a power law function of the density. Analyzing the relaxation process in the CRR, we also find that the string motion is the elementary process for the structural relaxation, which leads to the natural definition of the simultaneously rearranging region as the particles displaced in the string motion.

  19. Exploring the energy landscape of the charge transport levels in organic semiconductors at the molecular scale.

    Science.gov (United States)

    Cornil, J; Verlaak, S; Martinelli, N; Mityashin, A; Olivier, Y; Van Regemorter, T; D'Avino, G; Muccioli, L; Zannoni, C; Castet, F; Beljonne, D; Heremans, P

    2013-02-19

    strongly interacting electron-hole pairs can potentially escape from their Coulomb well, a process that is at the heart of photoconversion or molecular doping. Yet they do, with near-quantitative yield in some cases. Limited screening by the low dielectric medium in organic materials leads to subtle static and dynamic electronic polarization effects that strongly impact the energy landscape for charges, which offers a rationale for this apparent inconsistency. In this Account, we use different theoretical approaches to predict the energy landscape of charge carriers at the molecular level and review a few case studies highlighting the role of electrostatic interactions in conjugated organic molecules. We describe the pros and cons of different theoretical approaches that provide access to the energy landscape defining the motion of charge carriers. We illustrate the applications of these approaches through selected examples involving OFETs, OLEDs, and solar cells. The three selected examples collectively show that energetic disorder governs device performances and highlights the relevance of theoretical tools to probe energy landscapes in molecular assemblies.

  20. Energy landscape for martensitic phase transformation in shape memory NiTi

    International Nuclear Information System (INIS)

    Kibey, S.; Sehitoglu, H.; Johnson, D.D.

    2009-01-01

    First-principles calculations are presented for parent B2 phase and martensitic B19 and B19' phases in NiTi. The results indicate that both B19 and B19' are energetically more stable than the parent B2 phase. By means of ab initio density functional theory, the complete distortion-shuffle energy landscape associated with B2 → B19 transformation in NiTi is then determined. In addition to accounting for the Bain-type deformation through the Cauchy-Born rule, the study explicitly accounts for the shuffle displacements experienced by the internal ions in NiTi. The energy landscape allows the energy barrier associated with the B2 → B19 transformation pathway to be identified. The results indicate that a barrier of 0.48 mRyd atom -1 (relative to the B2 phase) must be overcome to transform the parent B2 NiTi to orthorhombic B19 martensite

  1. Quantitative analysis of the publishing landscape in high-energy physics

    International Nuclear Information System (INIS)

    Mele, Salvatore; Dallman, David; Vigen, Jens; Yeomans, Joanne

    2006-01-01

    World-wide collaboration in high-energy physics (HEP) is a tradition which dates back several decades, with scientific publications mostly coauthored by scientists from different countries. This coauthorship phenomenon makes it difficult to identify precisely the 'share' of each country in HEP scientific production. One year's worth of HEP scientific articles published in peer-reviewed journals is analysed and their authors are uniquely assigned to countries. This method allows the first correct estimation on a pro rata basis of the share of HEP scientific publishing among several countries and institutions. The results provide an interesting insight into the geographical collaborative patterns of the HEP community. The HEP publishing landscape is further analysed to provide information on the journals favoured by the HEP community and on the geographical variation of their author bases. These results provide quantitative input to the ongoing debate on the possible transition of HEP publishing to an Open Access model. Foreword. This paper reports the results of a recent detailed study of the publishing landscape in high energy physics. We thought that because of its direct relevance to the high energy physics community, this important quantitative input to the debate on the transition to Open Access naturally finds its place in our journal. Marc Henneaux, JHEP Scientific Director

  2. Obsolete or resurgent? The International Energy Agency in a changing global landscape

    International Nuclear Information System (INIS)

    Van de Graaf, Thijs

    2012-01-01

    Founded in response to the 1973 oil shock, the International Energy Agency (IEA) is arguably still the most important multilateral organization for energy-importing countries. Yet, the global geopolitical landscape has changed considerably since the IEA's creation. The rise of new energy consumers, new energy-related challenges and new international energy forums prompt a rethink of the agency's current role and institutional design. This article seeks to contribute to the recent debate on the future role of the IEA by examining specific drivers, avenues and constraints for institutional reform. The method used is SWOT analysis, which allows to summarize the key factors emanating from an assessment of an organization's internal characteristics (strengths and weaknesses) and its external environment (opportunities and threats). Building on this SWOT analysis, the article formulates a strategy for the IEA to remain the focal point in global energy governance. Key elements of this strategy include: stronger engagement with new consumers, rapprochement with OPEC, becoming a leading voice in the energy transition, and changing the agency's internal governance practices. - Highlights: ► The IEA is challenged by the rise of new consumers, threats and organizations. ► Assessment of the agency’s internal characteristics and external environment. ► The IEA needs to step up its outreach policy and fully embrace sustainable energy.

  3. A deterministic method for estimating free energy genetic network landscapes with applications to cell commitment and reprogramming paths.

    Science.gov (United States)

    Olariu, Victor; Manesso, Erica; Peterson, Carsten

    2017-06-01

    Depicting developmental processes as movements in free energy genetic landscapes is an illustrative tool. However, exploring such landscapes to obtain quantitative or even qualitative predictions is hampered by the lack of free energy functions corresponding to the biochemical Michaelis-Menten or Hill rate equations for the dynamics. Being armed with energy landscapes defined by a network and its interactions would open up the possibility of swiftly identifying cell states and computing optimal paths, including those of cell reprogramming, thereby avoiding exhaustive trial-and-error simulations with rate equations for different parameter sets. It turns out that sigmoidal rate equations do have approximate free energy associations. With this replacement of rate equations, we develop a deterministic method for estimating the free energy surfaces of systems of interacting genes at different noise levels or temperatures. Once such free energy landscape estimates have been established, we adapt a shortest path algorithm to determine optimal routes in the landscapes. We explore the method on three circuits for haematopoiesis and embryonic stem cell development for commitment and reprogramming scenarios and illustrate how the method can be used to determine sequential steps for onsets of external factors, essential for efficient reprogramming.

  4. Comparison of Recent Oil and Gas, Wind Energy, and Other Anthropogenic Landscape Alteration Factors in Texas Through 2014.

    Science.gov (United States)

    Pierre, Jon Paul; Wolaver, Brad D; Labay, Benjamin J; LaDuc, Travis J; Duran, Charles M; Ryberg, Wade A; Hibbitts, Toby J; Andrews, John R

    2018-05-01

    Recent research assessed how hydrocarbon and wind energy expansion has altered the North American landscape. Less understood, however, is how this energy development compares to other anthropogenic land use changes. Texas leads U.S. hydrocarbon production and wind power generation and has a rapidly expanding population. Thus, for ~47% of Texas (~324,000 km 2 ), we mapped the 2014 footprint of energy activities (~665,000 oil and gas wells, ~5700 wind turbines, ~237,000 km oil and gas pipelines, and ~2000 km electrical transmission lines). We compared the footprint of energy development to non-energy-related activities (agriculture, roads, urbanization) and found direct landscape alteration from all factors affects ~23% of the study area (~76,000 km 2 ), led by agriculture (~16%; ~52,882 km 2 ). Oil and gas activities altered turbine pads and ~10 km 2 from power transmission lines. We found that edge effects of widely-distributed energy infrastructure caused more indirect landscape alteration than larger, more concentrated urbanization and agriculture. This study presents a novel technique to quantify and compare anthropogenic activities causing both direct and indirect landscape alteration. We illustrate this landscape-mapping framework in Texas for the Spot-tailed Earless Lizard (Holbrookia lacerata); however, the approach can be applied to a range of species in developing regions globally.

  5. A Tale of Two Regions: Landscape Ecological Planning for Shale Gas Energy Futures

    Science.gov (United States)

    Murtha, T., Jr.; Schroth, O.; Orland, B.; Goldberg, L.; Mazurczyk, T.

    2015-12-01

    As we increasingly embrace deep shale gas deposits to meet global energy demands new and dispersed local and regional policy and planning challenges emerge. Even in regions with long histories of energy extraction, such as coal, shale gas and the infrastructure needed to produce the gas and transport it to market offers uniquely complex transformations in land use and landcover not previously experienced. These transformations are fast paced, dispersed and can overwhelm local and regional planning and regulatory processes. Coupled to these transformations is a structural confounding factor. While extraction and testing are carried out locally, regulation and decision-making is multilayered, often influenced by national and international factors. Using a geodesign framework, this paper applies a set of geospatial landscape ecological planning tools in two shale gas settings. First, we describe and detail a series of ongoing studies and tools that we have developed for communities in the Marcellus Shale region of the eastern United States, specifically the northern tier of Pennsylvania. Second, we apply a subset of these tools to potential gas development areas of the Fylde region in Lancashire, United Kingdom. For the past five years we have tested, applied and refined a set of place based and data driven geospatial models for forecasting, envisioning, analyzing and evaluating shale gas activities in northern Pennsylvania. These models are continuously compared to important landscape ecological planning challenges and priorities in the region, e.g. visual and cultural resource preservation. Adapting and applying these tools to a different landscape allow us to not only isolate and define important regulatory and policy exigencies in each specific setting, but also to develop and refine these models for broader application. As we continue to explore increasingly complex energy solutions globally, we need an equally complex comparative set of landscape ecological

  6. Protein Folding Free Energy Landscape along the Committor - the Optimal Folding Coordinate.

    Science.gov (United States)

    Krivov, Sergei V

    2018-06-06

    Recent advances in simulation and experiment have led to dramatic increases in the quantity and complexity of produced data, which makes the development of automated analysis tools very important. A powerful approach to analyze dynamics contained in such data sets is to describe/approximate it by diffusion on a free energy landscape - free energy as a function of reaction coordinates (RC). For the description to be quantitatively accurate, RCs should be chosen in an optimal way. Recent theoretical results show that such an optimal RC exists; however, determining it for practical systems is a very difficult unsolved problem. Here we describe a solution to this problem. We describe an adaptive nonparametric approach to accurately determine the optimal RC (the committor) for an equilibrium trajectory of a realistic system. In contrast to alternative approaches, which require a functional form with many parameters to approximate an RC and thus extensive expertise with the system, the suggested approach is nonparametric and can approximate any RC with high accuracy without system specific information. To avoid overfitting for a realistically sampled system, the approach performs RC optimization in an adaptive manner by focusing optimization on less optimized spatiotemporal regions of the RC. The power of the approach is illustrated on a long equilibrium atomistic folding simulation of HP35 protein. We have determined the optimal folding RC - the committor, which was confirmed by passing a stringent committor validation test. It allowed us to determine a first quantitatively accurate protein folding free energy landscape. We have confirmed the recent theoretical results that diffusion on such a free energy profile can be used to compute exactly the equilibrium flux, the mean first passage times, and the mean transition path times between any two points on the profile. We have shown that the mean squared displacement along the optimal RC grows linear with time as for

  7. A cavitation transition in the energy landscape of simple cohesive liquids and glasses

    International Nuclear Information System (INIS)

    Altabet, Y. Elia; Debenedetti, Pablo G.; Stillinger, Frank H.

    2016-01-01

    In particle systems with cohesive interactions, the pressure-density relationship of the mechanically stable inherent structures sampled along a liquid isotherm (i.e., the equation of state of an energy landscape) will display a minimum at the Sastry density ρ S . The tensile limit at ρ S is due to cavitation that occurs upon energy minimization, and previous characterizations of this behavior suggested that ρ S is a spinodal-like limit that separates all homogeneous and fractured inherent structures. Here, we revisit the phenomenology of Sastry behavior and find that it is subject to considerable finite-size effects, and the development of the inherent structure equation of state with system size is consistent with the finite-size rounding of an athermal phase transition. What appears to be a continuous spinodal-like point at finite system sizes becomes discontinuous in the thermodynamic limit, indicating behavior akin to a phase transition. We also study cavitation in glassy packings subjected to athermal expansion. Many individual expansion trajectories averaged together produce a smooth equation of state, which we find also exhibits features of finite-size rounding, and the examples studied in this work give rise to a larger limiting tension than for the corresponding landscape equation of state.

  8. The energy landscape of glassy dynamics on the amorphous hafnium diboride surface

    Science.gov (United States)

    Nguyen, Duc; Mallek, Justin; Cloud, Andrew N.; Abelson, John R.; Girolami, Gregory S.; Lyding, Joseph; Gruebele, Martin

    2014-11-01

    Direct visualization of the dynamics of structural glasses and amorphous solids on the sub-nanometer scale provides rich information unavailable from bulk or conventional single molecule techniques. We study the surface of hafnium diboride, a conductive ultrahigh temperature ceramic material that can be grown in amorphous films. Our scanning tunneling movies have a second-to-hour dynamic range and single-point current measurements extend that to the millisecond-to-minute time scale. On the a-HfB2 glass surface, two-state hopping of 1-2 nm diameter cooperatively rearranging regions or "clusters" occurs from sub-milliseconds to hours. We characterize individual clusters in detail through high-resolution (single cluster vertical displacements, we can reconstruct the local free energy landscape of individual clusters, complete with activation barrier height, a reaction coordinate in nanometers, and the shape of the free energy landscape basins between which hopping occurs. The experimental images are consistent with the compact shape of α-relaxors predicted by random first order transition theory, whereas the rapid hopping rate, even taking less confined motion at the surface into account, is consistent with β-relaxations. We make a proposal of how "mixed" features can show up in surface dynamics of glasses.

  9. Co-designing energy landscapes: Application of participatory mapping and geographic information systems in the exploration of low carbon futures

    NARCIS (Netherlands)

    Stremke, S.; Picchi, Paolo

    2017-01-01

    The chapter begins with a literature review of energy potential mapping, ecosystem services (ES) assessment and participatory mapping (PM). PM is a key technique to conduct tradeoff analysis while co-designing sustainable energy landscapes (SEL) with local communities. Stakeholders, among others,

  10. Communication: Theoretical prediction of free-energy landscapes for complex self-assembly

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, William M.; Reinhardt, Aleks; Frenkel, Daan [Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW (United Kingdom)

    2015-01-14

    We present a technique for calculating free-energy profiles for the nucleation of multicomponent structures that contain as many species as building blocks. We find that a key factor is the topology of the graph describing the connectivity of the target assembly. By considering the designed interactions separately from weaker, incidental interactions, our approach yields predictions for the equilibrium yield and nucleation barriers. These predictions are in good agreement with corresponding Monte Carlo simulations. We show that a few fundamental properties of the connectivity graph determine the most prominent features of the assembly thermodynamics. Surprisingly, we find that polydispersity in the strengths of the designed interactions stabilizes intermediate structures and can be used to sculpt the free-energy landscape for self-assembly. Finally, we demonstrate that weak incidental interactions can preclude assembly at equilibrium due to the combinatorial possibilities for incorrect association.

  11. Alternating access mechanisms of LeuT-fold transporters: trailblazing towards the promised energy landscapes.

    Science.gov (United States)

    Kazmier, Kelli; Claxton, Derek P; Mchaourab, Hassane S

    2017-08-01

    Secondary active transporters couple the uphill translocation of substrates to electrochemical ion gradients. Transporter conformational motion, generically referred to as alternating access, enables a central ligand binding site to change its orientation relative to the membrane. Here we review themes of alternating access and the transduction of ion gradient energy to power this process in the LeuT-fold class of transporters where crystallographic, computational and spectroscopic approaches have converged to yield detailed models of transport cycles. Specifically, we compare findings for the Na + -coupled amino acid transporter LeuT and the Na + -coupled hydantoin transporter Mhp1. Although these studies have illuminated multiple aspects of transporter structures and dynamics, a number of questions remain unresolved that so far hinder understanding transport mechanisms in an energy landscape perspective. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Lean production design using value stream mapping and ergonomics approach for waste elimination on buffing panel upright process

    Science.gov (United States)

    Suryoputro, M. R.; Sari, A. D.; Burhanudin, R.; Sugarindra, M.

    2017-12-01

    This study discussed the implementation of ergonomics and value stream mapping issues to reduce the existing waste in the process of buffing upright panel in the XYZ music manufacturing company. Aimed to identify the 9 waste based on the identification in terms of production processes and ergonomic factors, namely environmental health and safety, defects, overproduction, waiting, not utilizing employee knowledge skill and ability, transportation, inventory, motion, and excess process. In addition, ergonomics factors were identified, for example posture using REBA, job safety analysis, and physical workload. This study results indicated that the process is having 21.4% of the potential dangers that could not be accepted and thus potentially lead to lost time. Continued with the physical workload, the score of % cardiovascular load value is still below 30%, which means that the physical workload is normal and allows the addition of work. Meanwhile, in the calculation of posture investigation, the REBA resulted that there was a motion waste identified on the edge buff machine and ryoto with the score of 10 and 8. In conclusion, the results shown that there were 20 overall waste produced, then thus waste were reduced based on the identification and discussion of proposed improvements.

  13. Logistical concepts associated with international shipments using the USA/9904/B(U)F RTG Transportation System (RTGTS)

    International Nuclear Information System (INIS)

    Barklay, Chadwick D.; Miller, Roger G.; Pugh, Barry K.; Howell, Edwin I.

    1997-01-01

    Over the last 30 years, radioisotopes have provided heat from which electrical power is generated. For space missions, the isotope of choice has generally been 238 PuO 2 , its long half-life making it ideal for supplying power to remote satellites and spacecraft like the Voyager, Pioneer, and Viking missions, as well as the recently launched Galileo and Ulysses missions, and the presently planned Cassini mission. Electric power for future space missions will be provided by either radioisotopic thermoelectric generators (RTG), radioisotope thermophotovoltaic systems (RTPV), alkali metal thermal to electrical conversion (AMTEC) systems, radioisotope Stirling systems, or a combination of these. The type of electrical power system has yet to be specified for the 'Pluto Express' mission. However, the current plan does incorporate the use of Russian launch platforms for the spacecraft. The implied tasks associated with this plan require obtaining international certification for the transport of the radioisotopic power system, and resolving any logistical issues associated with the actual shipment of the selected radioisotopic power system. This paper presents a conceptual summary of the logistical considerations associated with shipping the selected radioisotopic power system using the USA/9904/B(U)F-85, Radioisotope Thermoelectric Generator Transportation System (RTGTS)

  14. Investigation of the Structures and Energy Landscapes of Thiocyanate-Water Clusters

    Directory of Open Access Journals (Sweden)

    Lewis C. Smeeton

    2017-03-01

    Full Text Available The Basin Hopping search method is used to find the global minima (GM and map the energy landscapes of thiocyanate-water clusters, (SCN−(H2On with 3–50 water molecules, with empirical potentials describing the ion-water and water-water interactions. (It should be noted that beyond n = 23, the lowest energy structures were only found in 1 out of 8 searches so they are unlikely to be the true GM but are indicative low energy structures. As for pure water clusters, the low energy isomers of thiocyanate-water clusters show a preponderance of fused water cubes and pentagonal prisms, with the weakly solvated thiocyanate ion lying on the surface, replacing two water molecules along an edge of a water polyhedron and with the sulfur atom in lower coordinated sites than nitrogen. However, by comparison with Density Functional Theory (DFT calculations, the empirical potential is found to overestimate the strength of the thiocyanate-water interaction, especially O–H⋯S, with low energy DFT structures having lower coordinate N and (especially S atoms than for the empirical potential. In the case of these finite ion-water clusters, the chaotropic (“disorder-making” thiocyanate ion weakens the water cluster structure but the water molecule arrangement is not significantly changed.

  15. Directed Magnetic Particle Transport above Artificial Magnetic Domains Due to Dynamic Magnetic Potential Energy Landscape Transformation.

    Science.gov (United States)

    Holzinger, Dennis; Koch, Iris; Burgard, Stefan; Ehresmann, Arno

    2015-07-28

    An approach for a remotely controllable transport of magnetic micro- and/or nanoparticles above a topographically flat exchange-bias (EB) thin film system, magnetically patterned into parallel stripe domains, is presented where the particle manipulation is achieved by sub-mT external magnetic field pulses. Superparamagnetic core-shell particles are moved stepwise by the dynamic transformation of the particles' magnetic potential energy landscape due to the external magnetic field pulses without affecting the magnetic state of the thin film system. The magnetic particle velocity is adjustable in the range of 1-100 μm/s by the design of the substrate's magnetic field landscape (MFL), the particle-substrate distance, and the magnitude of the applied external magnetic field pulses. The agglomeration of magnetic particles is avoided by the intrinsic magnetostatic repulsion of particles due to the parallel alignment of the particles' magnetic moments perpendicular to the transport direction and parallel to the surface normal of the substrate during the particle motion. The transport mechanism is modeled by a quantitative theory based on the precise knowledge of the sample's MFL and the particle-substrate distance.

  16. Impacts on the environment and landscape of new energy productions on farm parcels and buildings, Final report

    International Nuclear Information System (INIS)

    Pointereau, Ph.; Bochu, J.L.; Couturier, Ch.; Coulon, F.; Arnal, A.; Giorgis, S.

    2009-01-01

    This study aims at identifying positive and negative impacts of new energy productions implemented in farms on the environment (water, soil, biodiversity, space occupancy) and on landscapes, and at proposing techniques and regulations to strengthen positive consequences and to limit possible problems created by these energy productions. The considered productions are: trees apart from forest (hedges and copses), new farm energetic crops (Miscanthus for example), solar equipment (photovoltaic mounted on buildings or on ground, solar hot water and solar dryers), biogas production equipment, hydraulic micro-plants. The authors addressed the following environmental impacts: water (in quantity and quality), soils (quality, erosion risks), biodiversity, space occupancy (with respect to other activities), and landscape

  17. A data-driven analysis of energy balance closure across FLUXNET research sites: The role of landscape scale heterogeneity

    DEFF Research Database (Denmark)

    Stoy, Paul C.; Mauder, Matthias; Foken, Thomas

    2013-01-01

    approached 1. These results suggest that landscape-level heterogeneity in vegetation and topography cannot be ignored as a contributor to incomplete energy balance closure at the flux network level, although net radiation measurements, biological energy assimilation, unmeasured storage terms......The energy balance at most surface-atmosphere flux research sites remains unclosed. The mechanisms underlying the discrepancy between measured energy inputs and outputs across the global FLUXNET tower network are still under debate. Recent reviews have identified exchange processes and turbulent...... motions at large spatial and temporal scales in heterogeneous landscapes as the primary cause of the lack of energy balance closure at some intensively-researched sites, while unmeasured storage terms cannot be ruled out as a dominant contributor to the lack of energy balance closure at many other sites...

  18. A Community Landscape Model of Pro-Environmental Behavior: The Effects of Landscape and Community Interaction on Residential Energy Behaviors in Two Pennsylvania Towns

    Science.gov (United States)

    Mainzer, Stephen P.

    We are using more energy every year. Between 2001 and 2011, Pennsylvania residential electricity sales increased by two and a half times the number of new customers, accounting for almost one third of the state's total electricity consumption. Our ability to meet demand by acquiring new energy sources faces several challenges. Confusion surrounds the physical and economic accessibility of remaining fossil fuel sources. Immense land use requirements and subsequent environmental impacts challenge a total shift to renewable energy sources. The laws of thermodynamics limit the potential for new technology to efficiently convert raw energy to consumable sources. As a result, any rational strategy to meet future energy demands must involve conservation. Conservation is a pro-environmental behavior, an act intended to benefit the environment surrounding a person. I posit that a transdisciplinary model, the community landscape model of the pro-environmental behavior, unifies the conceptually analogous - yet disparate - fields of landscape, community, and behavior towards explaining residential energy conservation actions. Specifically, the study attempted to describe links between the physical environment, social environment, and conservation behaviors through a mixed-method framework. Two Pennsylvania townships - Spring and East Buffalo townships - were selected from an analysis of housing, electricity consumption, and land cover trends. Key informants from both townships informed the design of a survey instrument that captured the utility consumption, residential conservation actions, energy and environmental values, types and levels of community engagement, perceived barriers, and socio-demographic information from 107 randomly selected households. A mixed-method analysis produced evidence that place-based values and intention to participate in the community were significantly linked to lower utility consumption in households. People who cared deeply about their town

  19. Control over Structure and Function of Peptide Amphiphile Supramolecular Assemblies through Molecular Design and Energy Landscapes

    Science.gov (United States)

    Tantakitti, Faifan

    Supramolecular chemistry is a powerful tool to create a material of a defined structure with tunable properties. This strategy has led to catalytically active, bioactive, and environment-responsive materials, among others, that are valuable in applications ranging from sensor technology to energy and medicine. Supramolecular polymers formed by peptide amphiphiles (PAs) have been especially relevant in tissue regeneration due to their ability to form biocompatible structures and mimic many important signaling molecules in biology. These supramolecular polymers can form nanofibers that create networks which mimic natural extracellular matrices. PA materials have been shown to induce growth of blood vessels, bone, cartilage, and nervous tissue, among others. The work described in this thesis not only studied the relationship between molecular structure and functions of PA assemblies, but also uncovered a powerful link between the energy landscape of their supramolecular self-assembly and the ability of PA materials to interact with cells. In chapter 2, it is argued that fabricating fibrous nanostructures with defined mechanical properties and decoration with bioactive molecules is not sufficient to create a material that can effectively communicate with cells. By systemically placing the fibronectin-derived RGDS epitope at increasing distances from the surface of PA nanofibers through a linker of one to five glycine residues, integrin-mediated RGDS signaling was enhanced. The results suggested that the spatial presentation of an epitope on PA nanofibers strongly influences the bioactivity of the PA substrates. In further improving functionality of a PA-based scaffold to effectively direct cell growth and differentiation, chapter 3 explored the use of a cell microcarrier to compartmentalize and simultaneously tune insoluble and soluble signals in a single matrix. PA nanofibers were incorporated at the surface of the microcarrier in order to promote cell adhesion, while

  20. Golf-course and funnel energy landscapes: Protein folding concepts in martensites

    Science.gov (United States)

    Shankaraiah, N.

    2017-06-01

    We use protein folding energy landscape concepts such as golf course and funnel to study re-equilibration in athermal martensites under systematic temperature quench Monte Carlo simulations. On quenching below a transition temperature, the seeded high-symmetry parent-phase austenite that converts to the low-symmetry product-phase martensite, through autocatalytic twinning or elastic photocopying, has both rapid conversions and incubation delays in the temperature-time-transformation phase diagram. We find the rapid (incubation delays) conversions at low (high) temperatures arises from the presence of large (small) size of golf-course edge that has the funnel inside for negative energy states. In the incubating state, the strain structure factor enters into the Brillouin-zone golf course through searches for finite transitional pathways which close off at the transition temperature with Vogel-Fulcher divergences that are insensitive to Hamiltonian energy scales and log-normal distributions, as signatures of dominant entropy barriers. The crossing of the entropy barrier is identified through energy occupancy distributions, Monte Carlo acceptance fractions, heat emission, and internal work.

  1. PELE:  Protein Energy Landscape Exploration. A Novel Monte Carlo Based Technique.

    Science.gov (United States)

    Borrelli, Kenneth W; Vitalis, Andreas; Alcantara, Raul; Guallar, Victor

    2005-11-01

    Combining protein structure prediction algorithms and Metropolis Monte Carlo techniques, we provide a novel method to explore all-atom energy landscapes. The core of the technique is based on a steered localized perturbation followed by side-chain sampling as well as minimization cycles. The algorithm and its application to ligand diffusion are presented here. Ligand exit pathways are successfully modeled for different systems containing ligands of various sizes:  carbon monoxide in myoglobin, camphor in cytochrome P450cam, and palmitic acid in the intestinal fatty-acid-binding protein. These initial applications reveal the potential of this new technique in mapping millisecond-time-scale processes. The computational cost associated with the exploration is significantly less than that of conventional MD simulations.

  2. Quantitative analysis of the publishing landscape in High-Energy Physics

    CERN Document Server

    Mele, S; Vigen, Jens; Yeomans, Joanne

    2006-01-01

    World-wide collaboration in high-energy physics (HEP) is a tradition which dates back several decades, with scientific publications mostly coauthored by scientists from different countries. This coauthorship phenomenon makes it difficult to identify precisely the "share" of each country in HEP scientific production. One year's worth of HEP scientific articles published in peer-reviewed journals is analysed and their authors are uniquely assigned to countries. This method allows the first correct estimation on a pro rata basis of the share of HEP scientific publishing among several countries and institutions. The results provide an interesting insight into the geographical collaborative patterns of the HEP community. The HEP publishing landscape is further analysed to provide information on the journals favoured by the HEP community and on the geographical variation of their author bases. These results provide quantitative input to the ongoing debate on the possible transition of HEP publishing to an Open Acce...

  3. Free Energy Landscape of the Dissolution of Gibbsite at High pH

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Zhizhang; Kerisit, Sebastien N.; Stack, Andrew G.; Rosso, Kevin M.

    2018-03-26

    The individual elementary reactions involved in the dissolution of a solid into solution remain mostly speculative due to a lack of suitable, direct experimental probes. In this regard, we have applied atomistic simulations to map the free energy landscape of the dissolution of gibbsite from a step edge, as a model of metal hydroxide dissolution. The overall reaction combines kink site formation and kink site propagation. Two individual reactions were found to be rate-limiting for kink site formation, that is, the displacement of Al from a step site to a ledge adatom site and its detachment from ledge/terrace adatom sites into the solution. As a result, a pool of mobile and labile Al adsorbed species, or adatoms, exists before the release of Al into solution. Because of the quasi-hexagonal symmetry of gibbsite, kink site propagation can occur in multiple directions. Overall, the simulation results will enable the development of microscopic mechanistic models of metal oxide dissolution.

  4. The energy landscape of glassy dynamics on the amorphous hafnium diboride surface

    International Nuclear Information System (INIS)

    Nguyen, Duc; Girolami, Gregory S.; Mallek, Justin; Cloud, Andrew N.; Abelson, John R.; Lyding, Joseph; Gruebele, Martin

    2014-01-01

    Direct visualization of the dynamics of structural glasses and amorphous solids on the sub-nanometer scale provides rich information unavailable from bulk or conventional single molecule techniques. We study the surface of hafnium diboride, a conductive ultrahigh temperature ceramic material that can be grown in amorphous films. Our scanning tunneling movies have a second-to-hour dynamic range and single-point current measurements extend that to the millisecond-to-minute time scale. On the a-HfB 2 glass surface, two-state hopping of 1–2 nm diameter cooperatively rearranging regions or “clusters” occurs from sub-milliseconds to hours. We characterize individual clusters in detail through high-resolution (<0.5 nm) imaging, scanning tunneling spectroscopy and voltage modulation, ruling out individual atoms, diffusing adsorbates, or pinned charges as the origin of the observed two-state hopping. Smaller clusters are more likely to hop, larger ones are more likely to be immobile. HfB 2 has a very high bulk glass transition temperature T g , and we observe no three-state hopping or sequential two-state hopping previously seen on lower T g glass surfaces. The electronic density of states of clusters does not change when they hop up or down, allowing us to calibrate an accurate relative z-axis scale. By directly measuring and histogramming single cluster vertical displacements, we can reconstruct the local free energy landscape of individual clusters, complete with activation barrier height, a reaction coordinate in nanometers, and the shape of the free energy landscape basins between which hopping occurs. The experimental images are consistent with the compact shape of α-relaxors predicted by random first order transition theory, whereas the rapid hopping rate, even taking less confined motion at the surface into account, is consistent with β-relaxations. We make a proposal of how “mixed” features can show up in surface dynamics of glasses

  5. Crossover to potential energy landscape dominated dynamics in a model glass-forming liquid

    DEFF Research Database (Denmark)

    Schrøder, Thomas; Sastry, S.; Dyre, Jeppe

    2000-01-01

    An equilibrated model glass-forming liquid is studied by mapping successive configurations produced by molecular dynamics simulation onto a time series of inherent structures (local minima in the potential energy). Using this "inherent dynamics" approach we find direct numerical evidence for the ......An equilibrated model glass-forming liquid is studied by mapping successive configurations produced by molecular dynamics simulation onto a time series of inherent structures (local minima in the potential energy). Using this "inherent dynamics" approach we find direct numerical evidence...... for the long held view that below a crossover temperature, Tx, the liquid's dynamics can be separated into (i) vibrations around inherent structures and (ii) transitions between inherent structures [M. Goldstein, J. Chem. Phys. 51, 3728 (1969)], i.e., the dynamics become "dominated" by the potential energy...... landscape. In agreement with previous proposals, we find that Tx is within the vicinity of the mode-coupling critical temperature Tc. We further find that near Tx, transitions between inherent structures occur via cooperative, stringlike rearrangements of groups of particles moving distances substantially...

  6. Landscapes for Energy and Wildlife: Conservation Prioritization for Golden Eagles across Large Spatial Scales.

    Directory of Open Access Journals (Sweden)

    Jason D Tack

    Full Text Available Proactive conservation planning for species requires the identification of important spatial attributes across ecologically relevant scales in a model-based framework. However, it is often difficult to develop predictive models, as the explanatory data required for model development across regional management scales is rarely available. Golden eagles are a large-ranging predator of conservation concern in the United States that may be negatively affected by wind energy development. Thus, identifying landscapes least likely to pose conflict between eagles and wind development via shared space prior to development will be critical for conserving populations in the face of imposing development. We used publically available data on golden eagle nests to generate predictive models of golden eagle nesting sites in Wyoming, USA, using a suite of environmental and anthropogenic variables. By overlaying predictive models of golden eagle nesting habitat with wind energy resource maps, we highlight areas of potential conflict among eagle nesting habitat and wind development. However, our results suggest that wind potential and the relative probability of golden eagle nesting are not necessarily spatially correlated. Indeed, the majority of our sample frame includes areas with disparate predictions between suitable nesting habitat and potential for developing wind energy resources. Map predictions cannot replace on-the-ground monitoring for potential risk of wind turbines on wildlife populations, though they provide industry and managers a useful framework to first assess potential development.

  7. Anomalous dimensionality dependence of diffusion in a rugged energy landscape: How pathological is one dimension?

    Science.gov (United States)

    Seki, Kazuhiko; Bagchi, Kaushik; Bagchi, Biman

    2016-05-01

    Diffusion in one dimensional rugged energy landscape (REL) is predicted to be pathologically different (from any higher dimension) with a much larger chance of encountering broken ergodicity [D. L. Stein and C. M. Newman, AIP Conf. Proc. 1479, 620 (2012)]. However, no quantitative study of this difference has been reported, despite the prevalence of multidimensional physical models in the literature (like a high dimensional funnel guiding protein folding/unfolding). Paradoxically, some theoretical studies of these phenomena still employ a one dimensional diffusion description for analytical tractability. We explore the dimensionality dependent diffusion on REL by carrying out an effective medium approximation based analytical calculations and compare them with the available computer simulation results. We find that at an intermediate level of ruggedness (assumed to have a Gaussian distribution), where diffusion is well-defined, the value of the effective diffusion coefficient depends on dimensionality and changes (increases) by several factors (˜5-10) in going from 1d to 2d. In contrast, the changes in subsequent transitions (like 2d to 3d and 3d to 4d and so on) are far more modest, of the order of 10-20% only. When ruggedness is given by random traps with an exponential distribution of barrier heights, the mean square displacement (MSD) is sub-diffusive (a well-known result), but the growth of MSD is described by different exponents in one and higher dimensions. The reason for such strong ruggedness induced retardation in the case of one dimensional REL is discussed. We also discuss the special limiting case of infinite dimension (d = ∞) where the effective medium approximation becomes exact and where theoretical results become simple. We discuss, for the first time, the role of spatial correlation in the landscape on diffusion of a random walker.

  8. Tuning Surface Energy Landscapes in Metallic Quantum Films using Alkali Adsorbates

    Science.gov (United States)

    Khajetoorians, Alexander; Qin, Shengyong; Zhu, Wenguang; Eisele, Holger; Zhang, Zhenyu; Shih, Chih-Kang

    2008-03-01

    Quantum confinement shows a strong interplay with growth and kinetics in thin metal systems where the Fermi wavelength has a special relationship to the surface normal lattice constant. In the case of Pb/Si(111) systems, this relationship reveals an interesting thickness-dependent bilayer oscillation in the density of states and surface energy up to a phase. In this paper, we report on a novel effect: tuning of the energy landscape of a flat-top quantum Pb mesa using Cs adsorbates. Using STM/STS, we show that depositing Cs adsorbates on a thin Pb mesa promotes quantum stable Pb nanoislands on preferentially unstable thicknesses. Thickness-dependent nanoisland densities show a strong bilayer oscillation correlating with quantum stability. By modifying the Cs coverage on the mesa surface, we can tune the lateral size distribution of the nanoislands and the overall amplitude of the island density oscillation. Nanoisland formation is linked to a step decoration of Cs adatoms along the step edge of the nanoisland.

  9. Hybrid organic–inorganic inks flatten the energy landscape in colloidal quantum dot solids

    KAUST Repository

    Liu, Mengxia

    2016-11-14

    Bandtail states in disordered semiconductor materials result in losses in open-circuit voltage (Voc) and inhibit carrier transport in photovoltaics. For colloidal quantum dot (CQD) films that promise low-cost, large-area, air-stable photovoltaics, bandtails are determined by CQD synthetic polydispersity and inhomogeneous aggregation during the ligand-exchange process. Here we introduce a new method for the synthesis of solution-phase ligand-exchanged CQD inks that enable a flat energy landscape and an advantageously high packing density. In the solid state, these materials exhibit a sharper bandtail and reduced energy funnelling compared with the previous best CQD thin films for photovoltaics. Consequently, we demonstrate solar cells with higher Voc and more efficient charge injection into the electron acceptor, allowing the use of a closer-to-optimum bandgap to absorb more light. These enable the fabrication of CQD solar cells made via a solution-phase ligand exchange, with a certified power conversion efficiency of 11.28%. The devices are stable when stored in air, unencapsulated, for over 1,000 h.

  10. Strategies for the exploration of free energy landscapes: Unity in diversity and challenges ahead

    Directory of Open Access Journals (Sweden)

    Fabio Pietrucci

    2017-11-01

    Full Text Available Computer simulations play an important role in the study of transformation processes of condensed matter, including phase transitions, chemical reactions, and conformational changes of biomolecules. In principle, atomic trajectories, such as those generated using the molecular dynamics approach, contain detailed structural, thermodynamic, and kinetic information about activated processes. In practice, due to free energy barriers, there is often a wide gap between the time scale of the transformation and the time scale accessible with simulations. This review offers a practical guide to the ingenious methods aimed to accelerate the exploration and reconstruction of free energy landscapes of complex systems. The focus is on basic unifying concepts, successful strategies, and pitfalls, illustrated with examples of application to scientific problems from different disciplines. The current challenges in the field consist mainly in the cumbersome identification of optimal reaction coordinates and in the extensive recourse to expert human supervision and fine tuning of the algorithms. The full achievement of wide-spectrum formulations and easy reproducibility of results would constitute the breakthrough necessary to enter the era of routine use of enhanced sampling simulations.

  11. Hybrid organic–inorganic inks flatten the energy landscape in colloidal quantum dot solids

    KAUST Repository

    Liu, Mengxia; Voznyy, Oleksandr; Sabatini, Randy; Arquer, F.  Pelayo Garcí a de; Munir, Rahim; Balawi, Ahmed  Hesham; Lan, Xinzheng; Fan, Fengjia; Walters, Grant; Kirmani, Ahmad R.; Hoogland, Sjoerd; Laquai, Fré dé ric; Amassian, Aram; Sargent, Edward  H.

    2016-01-01

    Bandtail states in disordered semiconductor materials result in losses in open-circuit voltage (Voc) and inhibit carrier transport in photovoltaics. For colloidal quantum dot (CQD) films that promise low-cost, large-area, air-stable photovoltaics, bandtails are determined by CQD synthetic polydispersity and inhomogeneous aggregation during the ligand-exchange process. Here we introduce a new method for the synthesis of solution-phase ligand-exchanged CQD inks that enable a flat energy landscape and an advantageously high packing density. In the solid state, these materials exhibit a sharper bandtail and reduced energy funnelling compared with the previous best CQD thin films for photovoltaics. Consequently, we demonstrate solar cells with higher Voc and more efficient charge injection into the electron acceptor, allowing the use of a closer-to-optimum bandgap to absorb more light. These enable the fabrication of CQD solar cells made via a solution-phase ligand exchange, with a certified power conversion efficiency of 11.28%. The devices are stable when stored in air, unencapsulated, for over 1,000 h.

  12. Probing the energy landscape of alanine dipeptide and decalanine using temperature as a tunable parameter in molecular dynamics

    International Nuclear Information System (INIS)

    Chatterjee, A; Bhattacharya, S

    2016-01-01

    We perform several molecular dynamics (MD) calculations of solvated alanine dipeptide and decalanine in vacuum with temperature as a tunable parameter and in the process, generate Markov state models (MSMs) at each temperature. An interesting observation that the kinetic rates appear to obey the Arrhenius rate law allows us to predict the dynamics of alanine dipeptide at 300 K at the microsecond timescales using the nanoseconds long high temperature calculations without actually performing MD simulations at 300 K. We conclude that the energy landscape of alanine dipeptide contains superbasins deeper than k B T and determine the energy barriers associated with the moves from the Arrhenius rate expression. Similar insights regarding the energy landscape associated with folding/unfolding pathways of a deca-alanine molecule are obtained using kinetic rates calculated at different temperatures. (paper)

  13. Free energy landscape and multiple folding pathways of an H-type RNA pseudoknot.

    Directory of Open Access Journals (Sweden)

    Yunqiang Bian

    Full Text Available How RNA sequences fold to specific tertiary structures is one of the key problems for understanding their dynamics and functions. Here, we study the folding process of an H-type RNA pseudoknot by performing a large-scale all-atom MD simulation and bias-exchange metadynamics. The folding free energy landscapes are obtained and several folding intermediates are identified. It is suggested that the folding occurs via multiple mechanisms, including a step-wise mechanism starting either from the first helix or the second, and a cooperative mechanism with both helices forming simultaneously. Despite of the multiple mechanism nature, the ensemble folding kinetics estimated from a Markov state model is single-exponential. It is also found that the correlation between folding and binding of metal ions is significant, and the bound ions mediate long-range interactions in the intermediate structures. Non-native interactions are found to be dominant in the unfolded state and also present in some intermediates, possibly hinder the folding process of the RNA.

  14. Machine learning for the structure-energy-property landscapes of molecular crystals.

    Science.gov (United States)

    Musil, Félix; De, Sandip; Yang, Jack; Campbell, Joshua E; Day, Graeme M; Ceriotti, Michele

    2018-02-07

    Molecular crystals play an important role in several fields of science and technology. They frequently crystallize in different polymorphs with substantially different physical properties. To help guide the synthesis of candidate materials, atomic-scale modelling can be used to enumerate the stable polymorphs and to predict their properties, as well as to propose heuristic rules to rationalize the correlations between crystal structure and materials properties. Here we show how a recently-developed machine-learning (ML) framework can be used to achieve inexpensive and accurate predictions of the stability and properties of polymorphs, and a data-driven classification that is less biased and more flexible than typical heuristic rules. We discuss, as examples, the lattice energy and property landscapes of pentacene and two azapentacene isomers that are of interest as organic semiconductor materials. We show that we can estimate force field or DFT lattice energies with sub-kJ mol -1 accuracy, using only a few hundred reference configurations, and reduce by a factor of ten the computational effort needed to predict charge mobility in the crystal structures. The automatic structural classification of the polymorphs reveals a more detailed picture of molecular packing than that provided by conventional heuristics, and helps disentangle the role of hydrogen bonded and π-stacking interactions in determining molecular self-assembly. This observation demonstrates that ML is not just a black-box scheme to interpolate between reference calculations, but can also be used as a tool to gain intuitive insights into structure-property relations in molecular crystal engineering.

  15. Strong field-matching effects in superconducting YBa2Cu3O7-δ films with vortex energy landscapes engineered via masked ion irradiation

    Science.gov (United States)

    Swiecicki, I.; Ulysse, C.; Wolf, T.; Bernard, R.; Bergeal, N.; Briatico, J.; Faini, G.; Lesueur, J.; Villegas, Javier E.

    2012-06-01

    We have developed a masked ion irradiation technique to engineer the energy landscape for vortices in oxide superconductors. This approach associates the possibility to design the landscape geometry at the nanoscale with the unique capability to adjust the depth of the energy wells for vortices. This enabled us to unveil the key role of vortex channeling in modulating the amplitude of the field matching effects with the artificial energy landscape, and to make the latter govern flux dynamics over an unusually wide range of temperatures and applied fields for high-temperature superconducting films.

  16. Efficient Determination of Free Energy Landscapes in Multiple Dimensions from Biased Umbrella Sampling Simulations Using Linear Regression.

    Science.gov (United States)

    Meng, Yilin; Roux, Benoît

    2015-08-11

    The weighted histogram analysis method (WHAM) is a standard protocol for postprocessing the information from biased umbrella sampling simulations to construct the potential of mean force with respect to a set of order parameters. By virtue of the WHAM equations, the unbiased density of state is determined by satisfying a self-consistent condition through an iterative procedure. While the method works very effectively when the number of order parameters is small, its computational cost grows rapidly in higher dimension. Here, we present a simple and efficient alternative strategy, which avoids solving the self-consistent WHAM equations iteratively. An efficient multivariate linear regression framework is utilized to link the biased probability densities of individual umbrella windows and yield an unbiased global free energy landscape in the space of order parameters. It is demonstrated with practical examples that free energy landscapes that are comparable in accuracy to WHAM can be generated at a small fraction of the cost.

  17. Enhanced, targeted sampling of high-dimensional free-energy landscapes using variationally enhanced sampling, with an application to chignolin.

    Science.gov (United States)

    Shaffer, Patrick; Valsson, Omar; Parrinello, Michele

    2016-02-02

    The capabilities of molecular simulations have been greatly extended by a number of widely used enhanced sampling methods that facilitate escaping from metastable states and crossing large barriers. Despite these developments there are still many problems which remain out of reach for these methods which has led to a vigorous effort in this area. One of the most important problems that remains unsolved is sampling high-dimensional free-energy landscapes and systems that are not easily described by a small number of collective variables. In this work we demonstrate a new way to compute free-energy landscapes of high dimensionality based on the previously introduced variationally enhanced sampling, and we apply it to the miniprotein chignolin.

  18. Enhanced, targeted sampling of high-dimensional free-energy landscapes using variationally enhanced sampling, with an application to chignolin

    Science.gov (United States)

    Shaffer, Patrick; Valsson, Omar; Parrinello, Michele

    2016-01-01

    The capabilities of molecular simulations have been greatly extended by a number of widely used enhanced sampling methods that facilitate escaping from metastable states and crossing large barriers. Despite these developments there are still many problems which remain out of reach for these methods which has led to a vigorous effort in this area. One of the most important problems that remains unsolved is sampling high-dimensional free-energy landscapes and systems that are not easily described by a small number of collective variables. In this work we demonstrate a new way to compute free-energy landscapes of high dimensionality based on the previously introduced variationally enhanced sampling, and we apply it to the miniprotein chignolin. PMID:26787868

  19. Gentlest ascent dynamics for calculating first excited state and exploring energy landscape of Kohn-Sham density functionals.

    Science.gov (United States)

    Li, Chen; Lu, Jianfeng; Yang, Weitao

    2015-12-14

    We develop the gentlest ascent dynamics for Kohn-Sham density functional theory to search for the index-1 saddle points on the energy landscape of the Kohn-Sham density functionals. These stationary solutions correspond to excited states in the ground state functionals. As shown by various examples, the first excited states of many chemical systems are given by these index-1 saddle points. Our novel approach provides an alternative, more robust way to obtain these excited states, compared with the widely used ΔSCF approach. The method can be easily generalized to target higher index saddle points. Our results also reveal the physical interest and relevance of studying the Kohn-Sham energy landscape.

  20. Energy landscape, structure and rate effects on strength properties of alpha-helical proteins

    International Nuclear Information System (INIS)

    Bertaud, Jeremie; Hester, Joshua; Jimenez, Daniel D; Buehler, Markus J

    2010-01-01

    The strength of protein domains is crucial to identify the mechanical role of protein domains in biological processes such as mechanotransduction, tissue mechanics and tissue remodeling. Whereas the concept of strength has been widely investigated for engineered materials, the strength of fundamental protein material building blocks and how it depends on structural parameters such as the chemical bonding, the protein filament length and the timescale of observation or deformation velocity remains poorly understood. Here we report a systematic analysis of the influence of key parameters that define the energy landscape of the strength properties of alpha-helical protein domains, including energy barriers, unfolding and refolding distances, the locations of folded and unfolded states, as well as variations of the length and pulling velocity of alpha-helical protein filaments. The analysis is facilitated by the development of a double-well mesoscale potential formulation, utilized here to carry out a systematic numerical analysis of the behavior of alpha-helices. We compare the results against widely used protein strength models based on the Bell model, one of the simplest models used to characterize the strength of protein filaments. We find that, whereas Bell-type models are a reasonable approximation to describe the rupture of alpha-helical protein domains for a certain range of pulling speeds and values of energy barriers, the model ceases to hold for very large energy barriers and for very small pulling speeds, in agreement with earlier findings. We conclude with an application of our mesoscale model to investigate the effect of the length of alpha-helices on their mechanical strength. We find a weakening effect as the length of alpha-helical proteins increases, followed by an asymptotic regime in which the strength remains constant. We compare strand lengths found in biological proteins with the scaling law of strength versus alpha-helix filament length. The

  1. Statistical topography of fitness landscapes

    OpenAIRE

    Franke, Jasper

    2011-01-01

    Fitness landscapes are generalized energy landscapes that play an important conceptual role in evolutionary biology. These landscapes provide a relation between the genetic configuration of an organism and that organism’s adaptive properties. In this work, global topographical features of these fitness landscapes are investigated using theoretical models. The resulting predictions are compared to empirical landscapes. It is shown that these landscapes allow, at least with respe...

  2. The effect of tensile stress on the conformational free energy landscape of disulfide bonds.

    Directory of Open Access Journals (Sweden)

    Padmesh Anjukandi

    Full Text Available Disulfide bridges are no longer considered to merely stabilize protein structure, but are increasingly recognized to play a functional role in many regulatory biomolecular processes. Recent studies have uncovered that the redox activity of native disulfides depends on their C-C-S-S dihedrals, χ2 and χ'2. Moreover, the interplay of chemical reactivity and mechanical stress of disulfide switches has been recently elucidated using force-clamp spectroscopy and computer simulation. The χ2 and χ'2 angles have been found to change from conformations that are open to nucleophilic attack to sterically hindered, so-called closed states upon exerting tensile stress. In view of the growing evidence of the importance of C-C-S-S dihedrals in tuning the reactivity of disulfides, here we present a systematic study of the conformational diversity of disulfides as a function of tensile stress. With the help of force-clamp metadynamics simulations, we show that tensile stress brings about a large stabilization of the closed conformers, thereby giving rise to drastic changes in the conformational free energy landscape of disulfides. Statistical analysis shows that native TDi, DO and interchain Ig protein disulfides prefer open conformations, whereas the intrachain disulfide bridges in Ig proteins favor closed conformations. Correlating mechanical stress with the distance between the two a-carbons of the disulfide moiety reveals that the strain of intrachain Ig protein disulfides corresponds to a mechanical activation of about 100 pN. Such mechanical activation leads to a severalfold increase of the rate of the elementary redox S(N2 reaction step. All these findings constitute a step forward towards achieving a full understanding of functional disulfides.

  3. From Extraction of Local Structures of Protein Energy Landscapes to Improved Decoy Selection in Template-Free Protein Structure Prediction.

    Science.gov (United States)

    Akhter, Nasrin; Shehu, Amarda

    2018-01-19

    Due to the essential role that the three-dimensional conformation of a protein plays in regulating interactions with molecular partners, wet and dry laboratories seek biologically-active conformations of a protein to decode its function. Computational approaches are gaining prominence due to the labor and cost demands of wet laboratory investigations. Template-free methods can now compute thousands of conformations known as decoys, but selecting native conformations from the generated decoys remains challenging. Repeatedly, research has shown that the protein energy functions whose minima are sought in the generation of decoys are unreliable indicators of nativeness. The prevalent approach ignores energy altogether and clusters decoys by conformational similarity. Complementary recent efforts design protein-specific scoring functions or train machine learning models on labeled decoys. In this paper, we show that an informative consideration of energy can be carried out under the energy landscape view. Specifically, we leverage local structures known as basins in the energy landscape probed by a template-free method. We propose and compare various strategies of basin-based decoy selection that we demonstrate are superior to clustering-based strategies. The presented results point to further directions of research for improving decoy selection, including the ability to properly consider the multiplicity of native conformations of proteins.

  4. From Extraction of Local Structures of Protein Energy Landscapes to Improved Decoy Selection in Template-Free Protein Structure Prediction

    Directory of Open Access Journals (Sweden)

    Nasrin Akhter

    2018-01-01

    Full Text Available Due to the essential role that the three-dimensional conformation of a protein plays in regulating interactions with molecular partners, wet and dry laboratories seek biologically-active conformations of a protein to decode its function. Computational approaches are gaining prominence due to the labor and cost demands of wet laboratory investigations. Template-free methods can now compute thousands of conformations known as decoys, but selecting native conformations from the generated decoys remains challenging. Repeatedly, research has shown that the protein energy functions whose minima are sought in the generation of decoys are unreliable indicators of nativeness. The prevalent approach ignores energy altogether and clusters decoys by conformational similarity. Complementary recent efforts design protein-specific scoring functions or train machine learning models on labeled decoys. In this paper, we show that an informative consideration of energy can be carried out under the energy landscape view. Specifically, we leverage local structures known as basins in the energy landscape probed by a template-free method. We propose and compare various strategies of basin-based decoy selection that we demonstrate are superior to clustering-based strategies. The presented results point to further directions of research for improving decoy selection, including the ability to properly consider the multiplicity of native conformations of proteins.

  5. Modeling long-term changes in forested landscapes and their relation to the Earth's energy balance

    Science.gov (United States)

    Shugart, H. H.; Emanuel, W. R.; Solomon, A. M.

    1984-01-01

    The dynamics of the forested parts of the Earth's surface on time scales from decades to centuries are discussed. A set of computer models developed at Oak Ridge National Laboratory and elsewhere are applied as tools. These models simulate a landscape by duplicating the dynamics of growth, death and birth of each tree living on a 0.10 ha element of the landscape. This spatial unit is generally referred to as a gap in the case of the forest models. The models were tested against and applied to a diverse array of forests and appear to provide a reasonable representation for investigating forest-cover dynamics. Because of the climate linkage, one important test is the reconstruction of paleo-landscapes. Detailed reconstructions of changes in vegetation in response to changes in climate are crucial to understanding the association of the Earth's vegetation and climate and the response of the vegetation to climate change.

  6. The inherent dynamics of a molecular liquid: Geodesic pathways through the potential energy landscape of a liquid of linear molecules

    Science.gov (United States)

    Jacobson, Daniel; Stratt, Richard M.

    2014-05-01

    Because the geodesic pathways that a liquid follows through its potential energy landscape govern its slow, diffusive motion, we suggest that these pathways are logical candidates for the title of a liquid's "inherent dynamics." Like their namesake "inherent structures," these objects are simply features of the system's potential energy surface and thus provide views of the system's structural evolution unobstructed by thermal kinetic energy. This paper shows how these geodesic pathways can be computed for a liquid of linear molecules, allowing us to see precisely how such molecular liquids mix rotational and translational degrees of freedom into their dynamics. The ratio of translational to rotational components of the geodesic path lengths, for example, is significantly larger than would be expected on equipartition grounds, with a value that scales with the molecular aspect ratio. These and other features of the geodesics are consistent with a picture in which molecular reorientation adiabatically follows translation—molecules largely thread their way through narrow channels available in the potential energy landscape.

  7. Colloids exposed to random potential energy landscapes: From particle number density to particle-potential and particle-particle interactions

    International Nuclear Information System (INIS)

    Bewerunge, Jörg; Capellmann, Ronja F.; Platten, Florian; Egelhaaf, Stefan U.; Sengupta, Ankush; Sengupta, Surajit

    2016-01-01

    Colloidal particles were exposed to a random potential energy landscape that has been created optically via a speckle pattern. The mean particle density as well as the potential roughness, i.e., the disorder strength, were varied. The local probability density of the particles as well as its main characteristics were determined. For the first time, the disorder-averaged pair density correlation function g (1) (r) and an analogue of the Edwards-Anderson order parameter g (2) (r), which quantifies the correlation of the mean local density among disorder realisations, were measured experimentally and shown to be consistent with replica liquid state theory results.

  8. Oil and Gas Development in Southwestern Wyoming - Energy Data and Services for the Wyoming Landscape Conservation Initiative (WLCI)

    Science.gov (United States)

    Biewick, Laura

    2009-01-01

    The purpose of this report is to explore current oil and gas energy development in the area encompassing the Wyoming Landscape Conservation Initiative. The Wyoming Landscape Conservation Initiative is a long-term science-based effort to ensure southwestern Wyoming's wildlife and habitat remain viable in areas facing development pressure. Wyoming encompasses some of the highest quality wildlife habitats in the Intermountain West. At the same time, this region is an important source of natural gas. Using Geographic Information System technology, energy data pertinent to the conservation decision-making process have been assembled to show historical oil and gas exploration and production in southwestern Wyoming. In addition to historical data, estimates of undiscovered oil and gas are included from the 2002 U.S. Geological Survey National Assessment of Oil and Gas in the Southwestern Wyoming Province. This report is meant to facilitate the integration of existing data with new knowledge and technologies to analyze energy resources development and to assist in habitat conservation planning. The well and assessment data can be accessed and shared among many different clients including, but not limited to, an online web-service for scientists and resource managers engaged in the Initiative.

  9. Exploring the energy landscape of biopolymers using single molecule force spectroscopy and molecular simulations

    OpenAIRE

    Hyeon, Changbong

    2010-01-01

    In recent years, single molecule force techniques have opened a new avenue to decipher the folding landscapes of biopolymers by allowing us to watch and manipulate the dynamics of individual proteins and nucleic acids. In single molecule force experiments, quantitative analyses of measurements employing sound theoretical models and molecular simulations play central role more than any other field. With a brief description of basic theories for force mechanics and molecular simulation techniqu...

  10. Analyzing high resolution topography for advancing the understanding of mass and energy transfer through landscapes: A review

    Science.gov (United States)

    Passaiacquaa, Paola; Belmont, Patrick; Staley, Dennis M.; Simley, Jeffery; Arrowsmith, J. Ramon; Bode, Collin A.; Crosby, Christopher; DeLong, Stephen; Glenn, Nancy; Kelly, Sara; Lague, Dimitri; Sangireddy, Harish; Schaffrath, Keelin; Tarboton, David; Wasklewicz, Thad; Wheaton, Joseph

    2015-01-01

    The study of mass and energy transfer across landscapes has recently evolved to comprehensive considerations acknowledging the role of biota and humans as geomorphic agents, as well as the importance of small-scale landscape features. A contributing and supporting factor to this evolution is the emergence over the last two decades of technologies able to acquire high resolution topography (HRT) (meter and sub-meter resolution) data. Landscape features can now be captured at an appropriately fine spatial resolution at which surface processes operate; this has revolutionized the way we study Earth-surface processes. The wealth of information contained in HRT also presents considerable challenges. For example, selection of the most appropriate type of HRT data for a given application is not trivial. No definitive approach exists for identifying and filtering erroneous or unwanted data, yet inappropriate filtering can create artifacts or eliminate/distort critical features. Estimates of errors and uncertainty are often poorly defined and typically fail to represent the spatial heterogeneity of the dataset, which may introduce bias or error for many analyses. For ease of use, gridded products are typically preferred rather than the more information-rich point cloud representations. Thus many users take advantage of only a fraction of the available data, which has furthermore been subjected to a series of operations often not known or investigated by the user. Lastly, standard HRT analysis work-flows are yet to be established for many popular HRT operations, which has contributed to the limited use of point cloud data.In this review, we identify key research questions relevant to the Earth-surface processes community within the theme of mass and energy transfer across landscapes and offer guidance on how to identify the most appropriate topographic data type for the analysis of interest. We describe the operations commonly performed from raw data to raster products and

  11. Fugitive methane emissions from natural, urban, agricultural, and energy-production landscapes of eastern Australia

    Science.gov (United States)

    Kelly, Bryce F. J.; Iverach, Charlotte P.; Lowry, Dave; Fisher, Rebecca E.; France, James L.; Nisbet, Euan G.

    2015-04-01

    Modern cavity ringdown spectroscopy systems (CRDS) enable the continuous measurement of methane concentration. This allows for improved quantification of greenhouse gas emissions associated with various natural and human landscapes. We present a subset of over 4000 km of continuous methane surveying along the east coast of Australia, made using a Picarro G2301 CRDS, deployed in a utility vehicle with an air inlet above the roof at 2.2 mAGL. Measurements were made every 5 seconds to a precision of cut coal mines, unconventional gas developments (coal seam gas; CSG), and leaks detected in cities and country towns. In areas of dryland crops the median methane concentration was 1.78 ppm, while in the irrigation districts located on vertisol soils the concentration was as low as 1.76 ppm, which may indicate that these soils are a sink for methane. In the Hunter Valley, New South Wales, open-cut coal mining district we mapped a continuous 50 km interval where the concentration of methane exceeded 1.80 ppm. The median concentration in this interval was 2.02 ppm. Peak readings were beyond the range of the reliable measurement (in excess of 3.00 ppm). This extended plume is an amalgamation of plumes from 17 major pits 1 to 10 km in length. Adjacent to CSG developments in the Surat Basin, southeast Queensland, only small anomalies were detected near the well-heads. Throughout the vast majority of the gas fields the concentration of methane was below 1.80 ppm. The largest source of fugitive methane associated with CSG was off-gassing methane from the co-produced water holding ponds. At one location the down wind plume had a cross section of approximately 1 km where the concentration of methane was above 1.80 ppm. The median concentration within this section was 1.82 ppm, with a peak reading of 2.11 ppm. The ambient air methane concentration was always higher in urban environments compared to the surrounding countryside. Along one major road in Sydney we mapped an interval

  12. The energy landscapes of repeat-containing proteins: topology, cooperativity, and the folding funnels of one-dimensional architectures.

    Directory of Open Access Journals (Sweden)

    Diego U Ferreiro

    2008-05-01

    Full Text Available Repeat-proteins are made up of near repetitions of 20- to 40-amino acid stretches. These polypeptides usually fold up into non-globular, elongated architectures that are stabilized by the interactions within each repeat and those between adjacent repeats, but that lack contacts between residues distant in sequence. The inherent symmetries both in primary sequence and three-dimensional structure are reflected in a folding landscape that may be analyzed as a quasi-one-dimensional problem. We present a general description of repeat-protein energy landscapes based on a formal Ising-like treatment of the elementary interaction energetics in and between foldons, whose collective ensemble are treated as spin variables. The overall folding properties of a complete "domain" (the stability and cooperativity of the repeating array can be derived from this microscopic description. The one-dimensional nature of the model implies there are simple relations for the experimental observables: folding free-energy (DeltaG(water and the cooperativity of denaturation (m-value, which do not ordinarily apply for globular proteins. We show how the parameters for the "coarse-grained" description in terms of foldon spin variables can be extracted from more detailed folding simulations on perfectly funneled landscapes. To illustrate the ideas, we present a case-study of a family of tetratricopeptide (TPR repeat proteins and quantitatively relate the results to the experimentally observed folding transitions. Based on the dramatic effect that single point mutations exert on the experimentally observed folding behavior, we speculate that natural repeat proteins are "poised" at particular ratios of inter- and intra-element interaction energetics that allow them to readily undergo structural transitions in physiologically relevant conditions, which may be intrinsically related to their biological functions.

  13. The greenGain project - Biomass from landscape conservation and maintenance work for renewable energy production in the EU

    Science.gov (United States)

    Clalüna, Aline; Baumgarten, Wibke; García Galindo, Daniel; Lenz, Klaus; Doležal, Jan; De Filippi, Federico; Lorenzo, Joaquín; Montagnoli, Louis

    2017-04-01

    The project greenGain is looking for solutions to increase the energy production with regional and local biomass from landscape conservation and maintenance work, which is performed in the public interest. The relevant resources analysed in the greenGain model regions are, among others, biomass residues from clearing invasive vegetation in marginal agricultural lands in Spain, and residues from abandoned vineyards and olive groves in landscape protected areas in Italy. The main target groups are regional and local players who are responsible for maintenance and conservation work and for the biomass residue management in their regions. Moreover, the focus will be on service providers - including farmers and forest owners, their associations, NGOs, energy providers and consumers. Local companies, municipalities and public authorities are collaborating to identify the still underutilised non-food biomass resources and to discuss the way to integrate them into the local and regional biomass markets. Since the start of the three year project in January 2015, the partners from Italy, Spain, Czech Republic and Germany analysed, among other, the biomass feedstock potential coming from landscape maintenance work, and assessed various technological options to utilise this type of biomass. Further, political, legal and environmental aspects as well as awareness raising and public acceptance actions regarding the energetic use of biomass from public areas were assessed. greenGain also facilitates the exchange between model regions and other similar relevant players in the EU and shares examples of good practice. General guidelines will be prepared to guarantee a wide dissemination to other regions in the EU. Thus, the project shows how to build-up reliable knowledge on local availability of this feedstock and provides know-how concerning planning, harvesting, pre-treatment, storage and sustainable conversion pathways to a wide range of stakeholders in the EU.

  14. Structure prediction of nanoclusters; a direct or a pre-screened search on the DFT energy landscape?

    Science.gov (United States)

    Farrow, M R; Chow, Y; Woodley, S M

    2014-10-21

    The atomic structure of inorganic nanoclusters obtained via a search for low lying minima on energy landscapes, or hypersurfaces, is reported for inorganic binary compounds: zinc oxide (ZnO)n, magnesium oxide (MgO)n, cadmium selenide (CdSe)n, and potassium fluoride (KF)n, where n = 1-12 formula units. The computational cost of each search is dominated by the effort to evaluate each sample point on the energy landscape and the number of required sample points. The effect of changing the balance between these two factors on the success of the search is investigated. The choice of sample points will also affect the number of required data points and therefore the efficiency of the search. Monte Carlo based global optimisation routines (evolutionary and stochastic quenching algorithms) within a new software package, viz. Knowledge Led Master Code (KLMC), are employed to search both directly and after pre-screening on the DFT energy landscape. Pre-screening includes structural relaxation to minimise a cheaper energy function - based on interatomic potentials - and is found to improve significantly the search efficiency, and typically reduces the number of DFT calculations required to locate the local minima by more than an order of magnitude. Although the choice of functional form is important, the approach is robust to small changes to the interatomic potential parameters. The computational cost of initial DFT calculations of each structure is reduced by employing Gaussian smearing to the electronic energy levels. Larger (KF)n nanoclusters are predicted to form cuboid cuts from the rock-salt phase, but also share many structural motifs with (MgO)n for smaller clusters. The transition from 2D rings to 3D (bubble, or fullerene-like) structures occur at a larger cluster size for (ZnO)n and (CdSe)n. Differences between the HOMO and LUMO energies, for all the compounds apart from KF, are in the visible region of the optical spectrum (2-3 eV); KF lies deep in the UV region

  15. Free energy landscape and transition pathways from Watson–Crick to Hoogsteen base pairing in free duplex DNA

    Science.gov (United States)

    Yang, Changwon; Kim, Eunae; Pak, Youngshang

    2015-01-01

    Houghton (HG) base pairing plays a central role in the DNA binding of proteins and small ligands. Probing detailed transition mechanism from Watson–Crick (WC) to HG base pair (bp) formation in duplex DNAs is of fundamental importance in terms of revealing intrinsic functions of double helical DNAs beyond their sequence determined functions. We investigated a free energy landscape of a free B-DNA with an adenosine–thymine (A–T) rich sequence to probe its conformational transition pathways from WC to HG base pairing. The free energy landscape was computed with a state-of-art two-dimensional umbrella molecular dynamics simulation at the all-atom level. The present simulation showed that in an isolated duplex DNA, the spontaneous transition from WC to HG bp takes place via multiple pathways. Notably, base flipping into the major and minor grooves was found to play an important role in forming these multiple transition pathways. This finding suggests that naked B-DNA under normal conditions has an inherent ability to form HG bps via spontaneous base opening events. PMID:26250116

  16. Free energy landscape and transition pathways from Watson-Crick to Hoogsteen base pairing in free duplex DNA.

    Science.gov (United States)

    Yang, Changwon; Kim, Eunae; Pak, Youngshang

    2015-09-18

    Houghton (HG) base pairing plays a central role in the DNA binding of proteins and small ligands. Probing detailed transition mechanism from Watson-Crick (WC) to HG base pair (bp) formation in duplex DNAs is of fundamental importance in terms of revealing intrinsic functions of double helical DNAs beyond their sequence determined functions. We investigated a free energy landscape of a free B-DNA with an adenosine-thymine (A-T) rich sequence to probe its conformational transition pathways from WC to HG base pairing. The free energy landscape was computed with a state-of-art two-dimensional umbrella molecular dynamics simulation at the all-atom level. The present simulation showed that in an isolated duplex DNA, the spontaneous transition from WC to HG bp takes place via multiple pathways. Notably, base flipping into the major and minor grooves was found to play an important role in forming these multiple transition pathways. This finding suggests that naked B-DNA under normal conditions has an inherent ability to form HG bps via spontaneous base opening events. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  17. The significance of the amorphous potential energy landscape for dictating glassy dynamics and driving solid-state crystallisation

    DEFF Research Database (Denmark)

    Ruggiero, Michael T; Krynski, Marcin; Kissi, Eric Ofosu

    2017-01-01

    clear experimental and computational evidence in support of a theory that proposes that the shape and structure of the potential-energy surface (PES) is the fundamental factor underlying the glass-transition processes, regardless of the frequency that experimental methods probe. Whilst this has been....... Combined, these findings provide compelling evidence that the PES landscape, and the corresponding energy barriers, are the ultimate controlling feature behind the atomic and molecular dynamics of disordered solids, regardless of the frequency at which they occur....... proposed previously, we demonstrate, using ab initio molecular-dynamics (AIMD) simulations, that it is of critical importance to carefully consider the complete PES - both the intra-molecular and inter-molecular features - in order to fully understand the entire range of atomic-dynamical processes...

  18. The Swiss Energy Sector. Innovation landscape and chances for the Netherlands; De Zwitserse energiesector. Innovatielandschap en kansen voor Nederland

    Energy Technology Data Exchange (ETDEWEB)

    Van Ewijk, S. [Innovatie Attache Netwerk, Ambassad Berlijn, Berlin (Netherlands)

    2012-08-15

    An overview is given of innovation in the Swiss energy sector and the following research question will be answered: what are the characteristics of the Swiss innovation landscape in the energy sector and what opportunities are there for the Dutch energy sector? The emphasis is on themes that occur in the Dutch top sector policy, such as natural gas and energy conservation. The aim is to encourage cooperation between the Netherlands and Switzerland in the field of energy and provide inspiration for investment, policy solutions and markets in the field of energy. Each chapter contains references to Swiss authorities for more information and further steps [Dutch] Een overzicht wordt gegeven van innovatie in de Zwitserse energiesector en probeert de volgende onderzoeksvraag te beantwoorden: wat zijn de kenmerken van het Zwitserse innovatielandschap in de energiesector en welke kansen zijn er voor de Nederlandse energiesector? De nadruk ligt daarbij op thema's die ook in het Nederlandse topsectorbeleid voorkomen, zoals aardgas en energiebesparing. Het doel is om de samenwerking tussen Nederland en Zwitserland op energiegebied te stimuleren en informatie te bieden als inspiratie voor investeringen, beleidsoplossingen en afzetmarkten op energiegebied. Ieder hoofdstuk bevat verwijzingen naar Zwitserse instanties voor meer informatie en verdere stappen.

  19. Physical mechanism of mind changes and tradeoffs among speed, accuracy, and energy cost in brain decision making: Landscape, flux, and path perspectives

    International Nuclear Information System (INIS)

    Yan Han; Wang Jin; Zhang Kun

    2016-01-01

    Cognitive behaviors are determined by underlying neural networks. Many brain functions, such as learning and memory, have been successfully described by attractor dynamics. For decision making in the brain, a quantitative description of global attractor landscapes has not yet been completely given. Here, we developed a theoretical framework to quantify the landscape associated with the steady state probability distributions and associated steady state curl flux, measuring the degree of non-equilibrium through the degree of detailed balance breaking for decision making. We quantified the decision-making processes with optimal paths from the undecided attractor states to the decided attractor states, which are identified as basins of attractions, on the landscape. Both landscape and flux determine the kinetic paths and speed. The kinetics and global stability of decision making are explored by quantifying the landscape topography through the barrier heights and the mean first passage time. Our theoretical predictions are in agreement with experimental observations: more errors occur under time pressure. We quantitatively explored two mechanisms of the speed-accuracy tradeoff with speed emphasis and further uncovered the tradeoffs among speed, accuracy, and energy cost. Our results imply that there is an optimal balance among speed, accuracy, and the energy cost in decision making. We uncovered the possible mechanisms of changes of mind and how mind changes improve performance in decision processes. Our landscape approach can help facilitate an understanding of the underlying physical mechanisms of cognitive processes and identify the key factors in the corresponding neural networks. (paper)

  20. The importance of on-site evaluation for placing renewable energy in the landscape: A case study of the Búrfell wind farm (Iceland

    Directory of Open Access Journals (Sweden)

    Frantál Bohumil

    2017-12-01

    Full Text Available Using a case study of the Búrfell wind farm project, a large wind farm proposed in the Central Highlands of Iceland, the authors attempt to provide new insights into the factors shaping subjective landscape perceptions and attitudes to renewable energy developments, and into alternative methods that may be used for their assessment. The research was based on an on-site visit and actual experience of the place, investigated using a combination of mental mapping, the technique of the semantic differential and a questionnaire survey. The results show that participants visiting a landscape and using all sensory organs in combination with mental mapping, can reveal more important information than using only ‘laboratory’ methods with static photographs. The results suggest that the perception of landscape is highly subjective. Those perceiving the landscape as more open, homogenous, industrial, unfamiliar and resilient also consider it more compatible with wind turbines. The perception of the landscape’s compatibility with wind turbines proved to be a dominant factor shaping attitudes towards the project. The acceptance of wind turbines is not, however, inconsistent with the perception of landscape as beautiful, wild and unique. Participants from more densely populated countries and countries with a developed wind energy industry were more tolerant of wind turbines in the Icelandic landscape.

  1. Hierarchical structure of the energy landscape of proteins revisited by time series analysis. II. Investigation of explicit solvent effects

    Science.gov (United States)

    Alakent, Burak; Camurdan, Mehmet C.; Doruker, Pemra

    2005-10-01

    Time series analysis tools are employed on the principal modes obtained from the Cα trajectories from two independent molecular-dynamics simulations of α-amylase inhibitor (tendamistat). Fluctuations inside an energy minimum (intraminimum motions), transitions between minima (interminimum motions), and relaxations in different hierarchical energy levels are investigated and compared with those encountered in vacuum by using different sampling window sizes and intervals. The low-frequency low-indexed mode relationship, established in vacuum, is also encountered in water, which shows the reliability of the important dynamics information offered by principal components analysis in water. It has been shown that examining a short data collection period (100ps) may result in a high population of overdamped modes, while some of the low-frequency oscillations (memory: future conformations are less dependent on previous conformations due to the lowering of energy barriers in hierarchical levels of the energy landscape. In short-time dynamics (sight contradicts. However, this comes about because water enhances the transitions between minima and forces the protein to reduce its already inherent inability to maintain oscillations observed in vacuum. Some of the frequencies lower than 10cm-1 are found to be overdamped, while those higher than 20cm-1 are slightly increased. As for the long-time dynamics in water, it is found that random-walk motion is maintained for approximately 200ps (about five times of that in vacuum) in the low-indexed modes, showing the lowering of energy barriers between the higher-level minima.

  2. Landscape Studio

    DEFF Research Database (Denmark)

    Hansen, Peter Lundsgaard

    2017-01-01

    Landscape studio documents is the biography of the method 'design conversation' and contributes to the way we work with landscapes. The blog communicates renewed landscape didactics and leads to the innovation of design practices.......Landscape studio documents is the biography of the method 'design conversation' and contributes to the way we work with landscapes. The blog communicates renewed landscape didactics and leads to the innovation of design practices....

  3. The Energy Footprint on the Landscape and What this Means for Plants, Animals, and Ecosystems

    OpenAIRE

    Belnap, Jayne

    2012-01-01

    Dryland regions of the western U.S. contain abundant energy resources, whether they are traditional oil/gas or alternative sources such as solar or wind. With energy exploration and development comes surface disturbance and other impacts. The impact of energy exploration, such as running seismic lines, is associated with soil surface disruption that can be quite severe at a local level. Energy development brings a host of other concerns that need to be considered and likely mitigated. All ene...

  4. Addressing the trade-climate change-energy nexus: China's explorations in a global governance landscape

    OpenAIRE

    Monkelbaan, Joachim

    2014-01-01

    We have arrived at a critical juncture when it comes to understanding the numerous ways in which trade interacts with climate change and energy (trade-climate-energy nexus). Trade remains crucial for the sustainable development of the world's greatest trading nation: China. After clarifying the linkages within the trade, climate change and energy nexus, this article delves into China's specific needs and interests related to trade, climate change and energy. Then it explores the ways in which...

  5. Free energy landscape of dissociative adsorption of methane on ideal and defected graphene from ab initio simulations

    Science.gov (United States)

    Wlazło, M.; Majewski, J. A.

    2018-03-01

    We study the dissociative adsorption of methane at the surface of graphene. Free energy profiles, which include activation energies for different steps of the reaction, are computed from constrained ab initio molecular dynamics. At 300 K, the reaction barriers are much lower than experimental bond dissociation energies of gaseous methane, strongly indicating that the graphene surface acts as a catalyst of methane decomposition. On the other hand, the barriers are still much higher than on the nickel surface. Methane dissociation therefore occurs at a higher rate on nickel than on graphene. This reaction is a prerequisite for graphene growth from a precursor gas. Thus, the growth of the first monolayer should be a fast and efficient process while subsequent layers grow at a diminished rate and in a more controllable manner. Defects may also influence reaction energetics. This is evident from our results, in which simple defects (Stone-Wales defect and nitrogen substitution) lead to different free energy landscapes at both dissociation and adsorption steps of the process.

  6. Optimal dimensionality reduction of complex dynamics: the chess game as diffusion on a free-energy landscape.

    Science.gov (United States)

    Krivov, Sergei V

    2011-07-01

    Dimensionality reduction is ubiquitous in the analysis of complex dynamics. The conventional dimensionality reduction techniques, however, focus on reproducing the underlying configuration space, rather than the dynamics itself. The constructed low-dimensional space does not provide a complete and accurate description of the dynamics. Here I describe how to perform dimensionality reduction while preserving the essential properties of the dynamics. The approach is illustrated by analyzing the chess game--the archetype of complex dynamics. A variable that provides complete and accurate description of chess dynamics is constructed. The winning probability is predicted by describing the game as a random walk on the free-energy landscape associated with the variable. The approach suggests a possible way of obtaining a simple yet accurate description of many important complex phenomena. The analysis of the chess game shows that the approach can quantitatively describe the dynamics of processes where human decision-making plays a central role, e.g., financial and social dynamics.

  7. Free energy landscape of siRNA-polycation complexation: Elucidating the effect of molecular geometry, polymer flexibility, and charge neutralization.

    Directory of Open Access Journals (Sweden)

    Gianvito Grasso

    Full Text Available The success of medical threatments with DNA and silencing interference RNA is strongly related to the design of efficient delivery technologies. Cationic polymers represent an attractive strategy to serve as nucleic-acid carriers with the envisioned advantages of efficient complexation, low cost, ease of production, well-defined size, and low polydispersity index. However, the balance between efficacy and toxicity (safety of these polymers is a challenge and in need of improvement. With the aim of designing more effective polycationic-based gene carriers, many parameters such as carrier morphology, size, molecular weight, surface chemistry, and flexibility/rigidity ratio need to be taken into consideration. In the present work, the binding mechanism of three cationic polymers (polyarginine, polylysine and polyethyleneimine to a model siRNA target is computationally investigated at the atomistic level. In order to better understand the polycationic carrier-siRNA interactions, replica exchange molecular dynamic simulations were carried out to provide an exhaustive exploration of all the possible binding sites, taking fully into account the siRNA flexibility together with the presence of explicit solvent and ions. Moreover, well-tempered metadynamics simulations were employed to elucidate how molecular geometry, polycation flexibility, and charge neutralization affect the siRNA-polycations free energy landscape in term of low-energy binding modes and unbinding free energy barriers. Significant differences among polymer binding modes have been detected, revealing the advantageous binding properties of polyarginine and polylysine compared to polyethyleneimine.

  8. Efficient sampling over rough energy landscapes with high barriers: A combination of metadynamics with integrated tempering sampling

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y. Isaac [Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Zhang, Jun; Che, Xing; Yang, Lijiang; Gao, Yi Qin, E-mail: gaoyq@pku.edu.cn [Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Biodynamic Optical Imaging Center, Peking University, Beijing 100871 (China)

    2016-03-07

    In order to efficiently overcome high free energy barriers embedded in a complex energy landscape and calculate overall thermodynamics properties using molecular dynamics simulations, we developed and implemented a sampling strategy by combining the metadynamics with (selective) integrated tempering sampling (ITS/SITS) method. The dominant local minima on the potential energy surface (PES) are partially exalted by accumulating history-dependent potentials as in metadynamics, and the sampling over the entire PES is further enhanced by ITS/SITS. With this hybrid method, the simulated system can be rapidly driven across the dominant barrier along selected collective coordinates. Then, ITS/SITS ensures a fast convergence of the sampling over the entire PES and an efficient calculation of the overall thermodynamic properties of the simulation system. To test the accuracy and efficiency of this method, we first benchmarked this method in the calculation of ϕ − ψ distribution of alanine dipeptide in explicit solvent. We further applied it to examine the design of template molecules for aromatic meta-C—H activation in solutions and investigate solution conformations of the nonapeptide Bradykinin involving slow cis-trans isomerizations of three proline residues.

  9. Cellular network entropy as the energy potential in Waddington's differentiation landscape

    Science.gov (United States)

    Banerji, Christopher R. S.; Miranda-Saavedra, Diego; Severini, Simone; Widschwendter, Martin; Enver, Tariq; Zhou, Joseph X.; Teschendorff, Andrew E.

    2013-01-01

    Differentiation is a key cellular process in normal tissue development that is significantly altered in cancer. Although molecular signatures characterising pluripotency and multipotency exist, there is, as yet, no single quantitative mark of a cellular sample's position in the global differentiation hierarchy. Here we adopt a systems view and consider the sample's network entropy, a measure of signaling pathway promiscuity, computable from a sample's genome-wide expression profile. We demonstrate that network entropy provides a quantitative, in-silico, readout of the average undifferentiated state of the profiled cells, recapitulating the known hierarchy of pluripotent, multipotent and differentiated cell types. Network entropy further exhibits dynamic changes in time course differentiation data, and in line with a sample's differentiation stage. In disease, network entropy predicts a higher level of cellular plasticity in cancer stem cell populations compared to ordinary cancer cells. Importantly, network entropy also allows identification of key differentiation pathways. Our results are consistent with the view that pluripotency is a statistical property defined at the cellular population level, correlating with intra-sample heterogeneity, and driven by the degree of signaling promiscuity in cells. In summary, network entropy provides a quantitative measure of a cell's undifferentiated state, defining its elevation in Waddington's landscape. PMID:24154593

  10. Integration of ecological and thermodynamic concepts in the design of sustainable energy landscapes

    NARCIS (Netherlands)

    Stremke, S.; Koh, J.

    2011-01-01

    Resource depletion and climate change motivate a transition to sustainable energy systems that make effective use of renewable sources. Whereas nature presents strategies to sustain on the basis of renewables, the Laws of Thermodynamics can help to increase efficiency in energy use. In previous

  11. Jointly optimizing selection of fuel treatments and siting of forest biomass-based energy production facilities for landscape-scale fire hazard reduction.

    Science.gov (United States)

    Peter J. Daugherty; Jeremy S. Fried

    2007-01-01

    Landscape-scale fuel treatments for forest fire hazard reduction potentially produce large quantities of material suitable for biomass energy production. The analytic framework FIA BioSum addresses this situation by developing detailed data on forest conditions and production under alternative fuel treatment prescriptions, and computes haul costs to alternative sites...

  12. Identifying Greater Sage-Grouse source and sink habitats for conservation planning in an energy development landscape.

    Science.gov (United States)

    Kirol, Christopher P; Beck, Jeffrey L; Huzurbazar, Snehalata V; Holloran, Matthew J; Miller, Scott N

    2015-06-01

    Conserving a declining species that is facing many threats, including overlap of its habitats with energy extraction activities, depends upon identifying and prioritizing the value of the habitats that remain. In addition, habitat quality is often compromised when source habitats are lost or fragmented due to anthropogenic development. Our objective was to build an ecological model to classify and map habitat quality in terms of source or sink dynamics for Greater Sage-Grouse (Centrocercus urophasianus) in the Atlantic Rim Project Area (ARPA), a developing coalbed natural gas field in south-central Wyoming, USA. We used occurrence and survival modeling to evaluate relationships between environmental and anthropogenic variables at multiple spatial scales and for all female summer life stages, including nesting, brood-rearing, and non-brooding females. For each life stage, we created resource selection functions (RSFs). We weighted the RSFs and combined them to form a female summer occurrence map. We modeled survival also as a function of spatial variables for nest, brood, and adult female summer survival. Our survival-models were mapped as survival probability functions individually and then combined with fixed vital rates in a fitness metric model that, when mapped, predicted habitat productivity (productivity map). Our results demonstrate a suite of environmental and anthropogenic variables at multiple scales that were predictive of occurrence and survival. We created a source-sink map by overlaying our female summer occurrence map and productivity map to predict habitats contributing to population surpluses (source habitats) or deficits (sink habitat) and low-occurrence habitats on the landscape. The source-sink map predicted that of the Sage-Grouse habitat within the ARPA, 30% was primary source, 29% was secondary source, 4% was primary sink, 6% was secondary sink, and 31% was low occurrence. Our results provide evidence that energy development and avoidance of

  13. Energy landscapes of nucleophilic substitution reactions: a comparison of density functional theory and coupled cluster methods

    NARCIS (Netherlands)

    Swart, M.; Sola, M.; Bickelhaupt, F.M.

    2007-01-01

    We have carried out a detailed evaluation of the performance of all classes of density functional theory (DFT) for describing the potential energy surface (PES) of a wide range of nucleophilic substitution (S

  14. Structural and kinetic mapping of side-chain exposure onto the protein energy landscape.

    Science.gov (United States)

    Bernstein, Rachel; Schmidt, Kierstin L; Harbury, Pehr B; Marqusee, Susan

    2011-06-28

    Identification and characterization of structural fluctuations that occur under native conditions is crucial for understanding protein folding and function, but such fluctuations are often rare and transient, making them difficult to study. Native-state hydrogen exchange (NSHX) has been a powerful tool for identifying such rarely populated conformations, but it generally reveals no information about the placement of these species along the folding reaction coordinate or the barriers separating them from the folded state and provides little insight into side-chain packing. To complement such studies, we have performed native-state alkyl-proton exchange, a method analogous to NSHX that monitors cysteine modification rather than backbone amide exchange, to examine the folding landscape of Escherichia coli ribonuclease H, a protein well characterized by hydrogen exchange. We have chosen experimental conditions such that the rate-limiting barrier acts as a kinetic partition: residues that become exposed only upon crossing the unfolding barrier are modified in the EX1 regime (alkylation rates report on the rate of unfolding), while those exposed on the native side of the barrier are modified predominantly in the EX2 regime (alkylation rates report on equilibrium populations). This kinetic partitioning allows for identification and placement of partially unfolded forms along the reaction coordinate. Using this approach we detect previously unidentified, rarely populated conformations residing on the native side of the barrier and identify side chains that are modified only upon crossing the unfolding barrier. Thus, in a single experiment under native conditions, both sides of the rate-limiting barrier are investigated.

  15. Competitive landscape of the EU’s insulation materials industry for energy-efficient buildings

    OpenAIRE

    PAVEL CLAUDIU; BLAGOEVA DARINA

    2017-01-01

    Insulation materials could contribute significantly to improving the overall energy efficiency and sustainability of the buildings, especially by reducing the energy losses through the building envelope (walls, roofs, floors, etc.). The global demand for thermal insulation materials in building applications is projected to increase at a CAGR of 4.5 % between 2016 and 2027. In the EU the demand for thermal insulation materials is estimated at 3.48 % (2015-2027). Wool minerals (glass and stone ...

  16. Ratchet Effects and Domain Wall Energy Landscapes in Amorphous Magnetic Films with 2D Arrays of Asymmetric Holes

    Science.gov (United States)

    Martin, J. I.; Alija, A.; Sobrado, I.; Perez-Junquera, A.; Rodriguez-Rodriguez, G.; Velez, M.; Alameda, J. M.; Marconi, V. I.; Kolton, A. B.; Parrondo, J. M. R.

    2009-03-01

    The driven motion of domain walls in extended magnetic films patterned with 2D arrays of asymmetric holes has been found to be subject to two different crossed ratchet effects [1] which results in an inversion of the sign of domain wall motion rectification as a function of the applied magnetic field. This effect can be understood in terms of the competition between drive, elasticity and asymmetric pinning as revealed by a simple 4̂-model. In order to optimize the asymmetric hole design, the relevant energy landscapes for domain wall motion across the array of asymmetric holes have been calculated by micromagnetic simulations as a function of array geometrical characteristics. The effects of a transverse magnetic field on these two crossed ratchet effects will also be discussed in terms of the decrease in domain wall energy per unit area and of the modifications in the magnetostatic barriers for domain wall pinning at the asymmetric inclusions. Work supported by Spanish MICINN.[1] A. Perez-Junquera et al, Phys. Rev. Lett. 100 (2008) 037203

  17. Sub-seasonal thaw slump mass wasting is not consistently energy limited at the landscape scale

    Directory of Open Access Journals (Sweden)

    S. Zwieback

    2018-02-01

    Full Text Available Predicting future thaw slump activity requires a sound understanding of the atmospheric drivers and geomorphic controls on mass wasting across a range of timescales. On sub-seasonal timescales, sparse measurements indicate that mass wasting at active slumps is often limited by the energy available for melting ground ice, but other factors such as rainfall or the formation of an insulating veneer may also be relevant. To study the sub-seasonal drivers, we derive topographic changes from single-pass radar interferometric data acquired by the TanDEM-X satellites. The estimated elevation changes at 12 m resolution complement the commonly observed planimetric retreat rates by providing information on volume losses. Their high vertical precision (around 30 cm, frequent observations (11 days and large coverage (5000 km2 allow us to track mass wasting as drivers such as the available energy change during the summer of 2015 in two study regions. We find that thaw slumps in the Tuktoyaktuk coastlands, Canada, are not energy limited in June, as they undergo limited mass wasting (height loss of around 0 cm day−1 despite the ample available energy, suggesting the widespread presence of early season insulating snow or debris veneer. Later in summer, height losses generally increase (around 3 cm day−1, but they do so in distinct ways. For many slumps, mass wasting tracks the available energy, a temporal pattern that is also observed at coastal yedoma cliffs on the Bykovsky Peninsula, Russia. However, the other two common temporal trajectories are asynchronous with the available energy, as they track strong precipitation events or show a sudden speed-up in late August respectively. The observed temporal patterns are poorly related to slump characteristics like the headwall height. The contrasting temporal behaviour of nearby thaw slumps highlights the importance of complex local and temporally varying controls on mass wasting.

  18. Evapotranspiration and surface energy balance across an agricultural-urban landscape gradient in Southern California, USA.

    Science.gov (United States)

    Shiflett, S. A.; Anderson, R. G.; Jenerette, D.

    2014-12-01

    Urbanization substantially affects energy, surface and air temperature, and hydrology due to extensive modifications in land surface properties such as vegetation, albedo, thermal capacity and soil moisture. The magnitude and direction of these alterations depends heavily on the type of urbanization that occurs. We investigated energy balance variation in a local network of agricultural and urban ecosystems using the eddy covariance method to better understand how vegetation fraction and degree of urbanization affects energy exchanges between the land surface and the atmosphere. We deployed eddy flux systems within a well-irrigated, agricultural citrus orchard, a moderately developed urban zone with a substantial amount of local vegetative cover, and an intensely developed urban zone with minimal vegetative cover and increased impervious surfaces relative to the other two sites. Latent energy (LE) fluxes in the agricultural area ranged from 7.9 ± 1.4 W m-2 (nighttime) to 168.7 ± 6.2 W m-2 (daytime) compared to 10.2 ± 3.5 W m-2 and 40.6 ± 4.1 W m-2, respectively, for the moderately developed urban area. Sensible energy (H) fluxes ranged from -9.1 ± 1.0 W m-2 (nighttime) to 119 ± 7.0 W m-2 (daytime) in the agricultural area compared to 9.6 ± 2.6 W m-2 and 134 ± 6.0 W m-2, respectively, for the moderately developed urban zone. Daytime LE is reduced with increasing urbanization; however, daily cycles of LE are less recognizable in urban areas compared to distinct daily cycles obtained above a mature citrus crop. In contrast, both daytime and nighttime H increases with increasing degree of urbanization. Reduction in vegetation and increases in impervious surfaces along an urbanization gradient leads to alterations in energy balance, which are associated with microclimate and water use changes.

  19. The multi-state energy landscape of the SAM-I riboswitch: A single-molecule Förster resonance energy transfer spectroscopy study

    Science.gov (United States)

    Manz, Christoph; Kobitski, Andrei Yu.; Samanta, Ayan; Jäschke, Andres; Nienhaus, G. Ulrich

    2018-03-01

    RNA (ribonucleic acid) molecules are highly flexible biopolymers fluctuating at physiological temperatures among many different conformations that are represented by minima in a hierarchical conformational free energy landscape. Here we have employed single-molecule FRET (smFRET) to explore the energy landscape of the B. subtilis yitJ SAM-I riboswitch (RS). In this small RNA molecule, specific binding of an S-adenosyl-L-methionine (SAM) ligand in the aptamer domain regulates gene expression by inducing structural changes in another domain, the expression platform, causing transcription termination by the RNA polymerase. We have measured smFRET histograms over wide ranges of Mg2+ concentration for three RS variants that were specifically labeled with fluorescent dyes on different sites. In the analysis, different conformations are associated with discrete Gaussian model distributions, which are typically fairly broad on the FRET efficiency scale and thus can be extremely challenging to unravel due to their mutual overlap. Our earlier work on two SAM-I RS variants revealed four major conformations. By introducing a global fitting procedure which models both the Mg2+ concentration dependencies of the fractional populations and the average FRET efficiencies of the individual FRET distributions according to Mg2+ binding isotherms, we were able to consistently describe the histogram data of both variants at all studied Mg2+ concentrations. With the third FRET-labeled variant, however, we found significant deviations when applying the four-state model to the data. This can arise because the different FRET labeling of the new variant allows two states to be distinguished that were previously not separable due to overlap. Indeed, the resulting five-state model presented here consistently describes the smFRET histograms of all three variants as well as their variations with Mg2+ concentration. We also performed a triangulation of the donor position for two of the constructs

  20. Navigating the new deregulated landscape: Opportunities and risks for wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Fossum, D.J.; Hill, D.R. [Wiley, Rein & Fielding, Washington, DC (United States)

    1997-12-31

    Major changes in the law governing the electric industry are underway, fundamentally altering how the generation and sale of electric power is regulated and how electric power is marketed in the United States. Legislative and regulatory initiatives promoting competition will create a variety of opportunities, and commensurate risks, for power generators, marketers, brokers, sellers, and purchasers. To succeed in the new marketplace, suppliers of renewable energy must understand the changes occurring on the state and federal levels, and position themselves to take advantage of the opportunities available. In this environment, monitoring and participating in state and federal legislative and regulatory efforts will be crucial for maximizing opportunities for wind energy.

  1. Charting the energy landscape of metal/organic interfaces via machine learning

    Science.gov (United States)

    Scherbela, Michael; Hörmann, Lukas; Jeindl, Andreas; Obersteiner, Veronika; Hofmann, Oliver T.

    2018-04-01

    The rich polymorphism exhibited by inorganic/organic interfaces is a major challenge for materials design. In this work, we present a method to efficiently explore the potential energy surface and predict the formation energies of polymorphs and defects. This is achieved by training a machine learning model on a list of only 100 candidate structures that are evaluated via dispersion-corrected density functional theory (DFT) calculations. We demonstrate the power of this approach for tetracyanoethylene on Ag(100) and explain the anisotropic ordering that is observed experimentally.

  2. Dissipation of solar energy in landscape - controlled by management of water and vegetation

    Czech Academy of Sciences Publication Activity Database

    Pokorný, Jan

    2001-01-01

    Roč. 24, - (2001), s. 641-645 ISSN 0960-1481 R&D Projects: GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z6005908 Keywords : Solar energy dissipation * vegetation * production -evapotranspiration Subject RIV: DA - Hydrology ; Limnology Impact factor: 0.224, year: 2001

  3. Potential energy landscape signatures of slow dynamics in glass forming liquids

    DEFF Research Database (Denmark)

    Sastry, S.; Debenedetti, P. G.; Stillinger, F. H.

    1999-01-01

    We study the properties of local potential energy minima (‘inherent structures’) sampled by liquids at low temperatures as an approach to elucidating the mechanisms of the observed dynamical slowing down observed as the glass transition temperature is approached. This onset of slow dynamics...

  4. Addressing the trade-climate change-energy nexus: China's explorations in a global governance landscape

    Directory of Open Access Journals (Sweden)

    Joachim Monkelbaan

    2014-12-01

    As a way forward, different approaches towards the governance of trade and climate change will be highlighted. Besides discussing the specific aspects of Chinese participation in global trade and climate change governance, this paper aims at offering broader insights into the nexus between trade, energy and climate governance in China.

  5. America's Changing Energy Landscape - USGS National Coal Resources Data System Changes to National Energy Resources Data System.

    Science.gov (United States)

    East, J. A., II

    2016-12-01

    The U.S. Geological Survey's (USGS) Eastern Energy Resources Science Center (EERSC) has an ongoing project which has mapped coal chemistry and stratigraphy since 1977. Over the years, the USGS has collected various forms of coal data and archived that data into the National Coal Resources Data System (NCRDS) database. NCRDS is a repository that houses data from the major coal basins in the United States and includes information on location, seam thickness, coal rank, geologic age, geographic region, geologic province, coalfield, and characteristics of the coal or lithology for that data point. These data points can be linked to the US Coal Quality Database (COALQUAL) to include ultimate, proximate, major, minor and trace-element data. Although coal is an inexpensive energy provider, the United States has shifted away from coal usage recently and branched out into other forms of non-renewable and renewable energy because of environmental concerns. NCRDS's primary method of data capture has been USGS field work coupled with cooperative agreements with state geological agencies and universities doing coal-related research. These agreements are on competitive five-year cycles that have evolved into larger scope research efforts including solid fuel resources such as coal-bed methane, shale gas and oil. Recently these efforts have expanded to include environmental impacts of the use of fossil fuels, which has allowed the USGS to enter into agreements with states for the Geologic CO2 Storage Resources Assessment as required by the Energy Independence and Security Act. In 2016 they expanded into research areas to include geothermal, conventional and unconventional oil and gas. The NCRDS and COALQUAL databases are now online for the public to use, and are in the process of being updated to include new data for other energy resources. Along with this expansion of scope, the database name will change to the National Energy Resources Data System (NERDS) in FY 2017.

  6. Energy landscapes shape microbial communities in hydrothermal systems on the Arctic Mid-Ocean Ridge

    OpenAIRE

    Dahle, H?kon; ?kland, Ingeborg; Thorseth, Ingunn H; Pederesen, Rolf B; Steen, Ida H

    2015-01-01

    Methods developed in geochemical modelling combined with recent advances in molecular microbial ecology provide new opportunities to explore how microbial communities are shaped by their chemical surroundings. Here, we present a framework for analyses of how chemical energy availability shape chemotrophic microbial communities in hydrothermal systems through an investigation of two geochemically different basalt-hosted hydrothermal systems on the Arctic Mid-Ocean Ridge: the Soria Moria Vent f...

  7. Landscapes of lost energy: counterfactual geographical imaginary for a more sustainable society

    Czech Academy of Sciences Publication Activity Database

    Van der Horst, Dan

    2014-01-01

    Roč. 22, č. 2 (2014), s. 66-72 ISSN 1210-8812 R&D Projects: GA MŠk EE2.3.20.0025 Institutional support: RVO:68145535 Keywords : counterfactual * imagery * imagination * energy literacy Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 0.872, year: 2014 http://www.geonika.cz/EN/research/ENMgr/MGR_2014_02.pdf

  8. Landscapes of Lost Energy: Counterfactual Geographical Imaginary for A More Sustainable Society

    Directory of Open Access Journals (Sweden)

    van der Horst Dan

    2014-07-01

    Full Text Available The quest for sustainable energy, one of the greatest challenges of the 21st century, calls for more input from academics than 'simply' producing good science. Geographical imaginations are as old as storytelling and mapmaking, but this essay is neither about 'long ago and far away', nor about utopian energy futures. This is a call to geographers to engage with 'alternative present' energy scenarios, using the full range of analytical and discursive tools at our disposal. Drawing on a diverse tradition of imagined spaces and the awareness of absences (material, relational or otherwise, geographers should be able to contribute to the quest for a more sustainable society by assessing, envisaging, and communicating a counterfactual 'here and now', based on good practices existing right now, but not (yet right here. We need to understand how much more sustainable our bit of the planet would be if we could just, environmentally speaking, 'keep up' with the best of our neighbours. This counterfactual present should be seen as neither radical nor utopian, because it only assumes the historic adoption of best practices which we now know to be feasible and successful. And if thi alternative current scenario looks radically different from the 'real' state we are in, then this goes to show how radically unsustainable our business-as-usual approach has been.

  9. RAAAF's office landscape The End of Sitting: Energy expenditure and temporary comfort when working in non-sitting postures.

    Directory of Open Access Journals (Sweden)

    Simone R Caljouw

    Full Text Available An earlier study suggested that the activity-inviting office landscape called "The End of Sitting", designed by Rietveld Architecture Art Affordances (RAAAF, should be considered as an alternative working environment to prevent sedentary behavior. The End of Sitting lacks chairs and tables but consists instead of a myriad of sloped surfaces at different heights that afford workers to stand, lean or recline at different locations. In this study, we assessed the impact of four of its workspaces on physical intensity, temporary comfort and productivity of office work and compared the outcomes with sitting and standing behind a desk. Twenty-four participants worked for 10 minutes in each of the six test conditions. Energy expenditure, measured by indirect calorimetry, and heart rate were recorded. Questionnaires were used to assess the perceived comfort. The number of words found in the word search test was counted as a measure of productivity. The majority of The End of Sitting workspaces led to a significant increase in energy expenditure compared with sitting behind a desk (ps < .05. Average MET values ranged from 1.40 to 1.58 which is a modest rise in energy expenditure compared to sitting (1.32 METs and not significantly different from standing (1.47 METs. The scores on the general comfort scale indicated that some workspaces were less comfortable than sitting (ps < .05, but the vast majority of participants reported that at least one of The End of Sitting workspaces was equally or more comfortable than sitting. No differences in productivity between the test conditions were found. Further long-term studies are required to assess the behavioral adaptations, productivity and the level of comfort when using The End of Sitting as a permanent office.

  10. Elucidation of the conformational free energy landscape in H.pylori LuxS and its implications to catalysis

    Directory of Open Access Journals (Sweden)

    Bhattacharyya Moitrayee

    2010-08-01

    Full Text Available Abstract Background One of the major challenges in understanding enzyme catalysis is to identify the different conformations and their populations at detailed molecular level in response to ligand binding/environment. A detail description of the ligand induced conformational changes provides meaningful insights into the mechanism of action of enzymes and thus its function. Results In this study, we have explored the ligand induced conformational changes in H.pylori LuxS and the associated mechanistic features. LuxS, a dimeric protein, produces the precursor (4,5-dihydroxy-2,3-pentanedione for autoinducer-2 production which is a signalling molecule for bacterial quorum sensing. We have performed molecular dynamics simulations on H.pylori LuxS in its various ligand bound forms and analyzed the simulation trajectories using various techniques including the structure network analysis, free energy evaluation and water dynamics at the active site. The results bring out the mechanistic details such as co-operativity and asymmetry between the two subunits, subtle changes in the conformation as a response to the binding of active and inactive forms of ligands and the population distribution of different conformations in equilibrium. These investigations have enabled us to probe the free energy landscape and identify the corresponding conformations in terms of network parameters. In addition, we have also elucidated the variations in the dynamics of water co-ordination to the Zn2+ ion in LuxS and its relation to the rigidity at the active sites. Conclusions In this article, we provide details of a novel method for the identification of conformational changes in the different ligand bound states of the protein, evaluation of ligand-induced free energy changes and the biological relevance of our results in the context of LuxS structure-function. The methodology outlined here is highly generalized to illuminate the linkage between structure and function in

  11. Spatial demographic models to inform conservation planning of golden eagles in renewable energy landscapes

    Science.gov (United States)

    Wiens, J. David; Schumaker, Nathan H.; Inman, Richard D.; Esque, Todd C.; Longshore, Kathleen M.; Nussear, Kenneth E

    2017-01-01

    Spatial demographic models can help guide monitoring and management activities targeting at-risk species, even in cases where baseline data are lacking. Here, we provide an example of how site-specific changes in land use and anthropogenic stressors can be incorporated into a spatial demographic model to investigate effects on population dynamics of Golden Eagles (Aquila chrysaetos). Our study focused on a population of Golden Eagles exposed to risks associated with rapid increases in renewable energy development in southern California, U.S.A. We developed a spatially explicit, individual-based simulation model that integrated empirical data on demography of Golden Eagles with spatial data on the arrangement of nesting habitats, prey resources, and planned renewable energy development sites. Our model permitted simulated eagles of different stage-classes to disperse, establish home ranges, acquire prey resources, prospect for breeding sites, and reproduce. The distribution of nesting habitats, prey resources, and threats within each individual's home range influenced movement, reproduction, and survival. We used our model to explore potential effects of alternative disturbance scenarios, and proposed conservation strategies, on the future distribution and abundance of Golden Eagles in the study region. Results from our simulations suggest that probable increases in mortality associated with renewable energy infrastructure (e.g., collisions with wind turbines and vehicles, electrocution on power poles) could have negative consequences for population trajectories, but that site-specific conservation actions could reduce the magnitude of negative effects. Our study demonstrates the use of a flexible and expandable modeling framework to incorporate spatially dependent processes when determining relative effects of proposed management options to Golden Eagles and their habitats.

  12. Canvassing the Cyber Security Landscape: Why Energy Companies Need to Pay Attention

    OpenAIRE

    Averill, B.; Luiijf, H.A.M.

    2010-01-01

    Recent news of a “highly sophisticated and targeted” cyber attack on Google, Yahoo, and perhaps on as many as a dozen other companies has once again brought the issue of cyber security to the top of the news. Internet companies, however, are not the only ones vulnerable to such attacks. Over the past decade, a series of events has highlighted the vulnerability of the electric grid and other energy infrastructures to both cyber disruptions (due, e.g., to malware) and from outside attacks using...

  13. The market of energy storage. Stakes and perspectives by 2020 - Analysis of the competitive landscape

    International Nuclear Information System (INIS)

    2013-01-01

    Within a context of lack of regulatory framework, of existence of technological deadlocks, and of absence of any defined business model, this publication reports a study of the emerging market of energy storage. It examines the role public authorities can play to promote investments in this sector, what are the opportunities for operators, and which are the perspectives on the middle term for the French market. In order to highlight recent and future evolutions of stationary and embarked storage, the authors propose an analysis of the main market growth drivers and brakes, a focus on the impact of regulatory, legal, economic, tax-related, technological, and social-cultural factors on sector stakeholders. They also propose an overview of the market status for the cases of stationary and embarked storage, and of the main challenges for these both segments. A panorama of existing actors is given with an analysis of their position, strengths and weaknesses, and of the main axis of development for 4 categories of actors (industries, battery manufacturers, energy operators, and start ups)

  14. 3D modeling of satellite spectral images, radiation budget and energy budget of urban landscapes

    Science.gov (United States)

    Gastellu-Etchegorry, J. P.

    2008-12-01

    DART EB is a model that is being developed for simulating the 3D (3 dimensional) energy budget of urban and natural scenes, possibly with topography and atmosphere. It simulates all non radiative energy mechanisms (heat conduction, turbulent momentum and heat fluxes, water reservoir evolution, etc.). It uses DART model (Discrete Anisotropic Radiative Transfer) for simulating radiative mechanisms: 3D radiative budget of 3D scenes and their remote sensing images expressed in terms of reflectance or brightness temperature values, for any atmosphere, wavelength, sun/view direction, altitude and spatial resolution. It uses an innovative multispectral approach (ray tracing, exact kernel, discrete ordinate techniques) over the whole optical domain. This paper presents two major and recent improvements of DART for adapting it to urban canopies. (1) Simulation of the geometry and optical characteristics of urban elements (houses, etc.). (2) Modeling of thermal infrared emission by vegetation and urban elements. The new DART version was used in the context of the CAPITOUL project. For that, districts of the Toulouse urban data base (Autocad format) were translated into DART scenes. This allowed us to simulate visible, near infrared and thermal infrared satellite images of Toulouse districts. Moreover, the 3D radiation budget was used by DARTEB for simulating the time evolution of a number of geophysical quantities of various surface elements (roads, walls, roofs). Results were successfully compared with ground measurements of the CAPITOUL project.

  15. Energy landscape and dynamics of brain activity during human bistable perception.

    Science.gov (United States)

    Watanabe, Takamitsu; Masuda, Naoki; Megumi, Fukuda; Kanai, Ryota; Rees, Geraint

    2014-08-28

    Individual differences in the structure of parietal and prefrontal cortex predict the stability of bistable visual perception. However, the mechanisms linking such individual differences in brain structures to behaviour remain elusive. Here we demonstrate a systematic relationship between the dynamics of brain activity, cortical structure and behaviour underpinning bistable perception. Using fMRI in humans, we find that the activity dynamics during bistable perception are well described as fluctuating between three spatially distributed energy minimums: visual-area-dominant, frontal-area-dominant and intermediate states. Transitions between these energy minimums predicted behaviour, with participants whose brain activity tend to reflect the visual-area-dominant state exhibiting more stable perception and those whose activity transits to frontal-area-dominant states reporting more frequent perceptual switches. Critically, these brain activity dynamics are correlated with individual differences in grey matter volume of the corresponding brain areas. Thus, individual differences in the large-scale dynamics of brain activity link focal brain structure with bistable perception.

  16. Impacts of the cultivation of energy crops for generation of biogas on the landscape structure and avifauna; Auswirkungen des Energiepflanzenanbaus zur Biogaserzeugung auf Landschaftsstruktur und Avifauna

    Energy Technology Data Exchange (ETDEWEB)

    Ruehmkorf, Hilke

    2011-07-01

    In its effort to implement new climate and energy policies, Germany has been heavily promoting the adoption of renewable energies. This has brought about a dramatic change in the use of arable land during the last years. The primary objective of this study was therefore to assess the effect of energy cropping on existing landscape structures in intensively cultivated regions in the course of the year. According to the available structural parameters an investigation was conducted to ascertain the fallout of energy plant cultivation on both migratory and overwintering birds. The period covered entailed the winter months. Both the advent of the energy crops as well as the associated biogas facilities that sprang up outside built-in areas seem to have reshaped the existing agricultural landscape. Hence, an additional aim of this study was to identify birds that use biogas plants for breeding or as a feeding habitat in winter. In conclusion, it can be asserted that energy crops can definitely contribute to the expansion of structural diversity in the agricultural landscape provided those energy crops were not cultivated on a large scale prior to the advent of the biogas facilities. Hence, there is still room for further energy crop diversification as its potential has not been exhausted. During the winter months mostly common species such as the carrion crow or the wood pigeon consider the maize fields as a viable source of nutrition. Cranes are seen as newcomers, as they probably started resting in the 'Boerde' precisely due to the advent of energy maize cultivation. And more availability of nourishment when the ground is covered by snow is another benefit the avifauna reaps from biogas plants. However, for endangered farmland birds this type of nutrition is a rarely used source, as it runs counter to their escape strategies and food preferences. For these species the habitat function and the food availability depends especially on how the land is managed (e

  17. Information Resources in High-Energy Physics Surveying the Present Landscape and Charting the Future Course

    CERN Document Server

    Gentil-Beccot, Anne; Mele, Salvatore; Holtkamp, Annette; O'Connell, Heath B; Brooks, Travis C

    2009-01-01

    Access to previous results is of paramount importance in the scientific process. Recent progress in information management focuses on building e-infrastructures for the optimization of the research workflow, through both policy-driven and user-pulled dynamics. For decades, High-Energy Physics (HEP) has pioneered innovative solutions in the field of information management and dissemination. In light of a transforming information environment, it is important to assess the current usage of information resources by researchers and HEP provides a unique test-bed for this assessment. A survey of about 10% of practitioners in the field reveals usage trends and information needs. Community-based services, such as the pioneering arXiv and SPIRES systems, largely answer the need of the scientists, with a limited but increasing fraction of younger users relying on Google. Commercial services offered by publishers or database vendors are essentially unused in the field. The survey offers an insight into the most importan...

  18. Photovoltaic performance and the energy landscape of CH3NH3PbI3.

    Science.gov (United States)

    Zhou, Yecheng; Huang, Fuzhi; Cheng, Yi-Bing; Gray-Weale, Angus

    2015-09-21

    Photovoltaic cells with absorbing layers of certain perovskites have power conversion efficiencies up to 20%. Among these materials, CH3NH3PbI3 is widely used. Here we use density-functional theory to calculate the energies and rotational energy barriers of a methylammonium ion in the α or β phase of CH3NH3PbI3 with differently oriented neighbouring methylammonium ions. Our results suggest the methylammonium ions in CH3NH3PbI3 prefer to rotate collectively, and to be parallel to their neighbours. Changes in polarization on rotation of methylammonium ions are two to three times larger than those on relaxation of the lead ion from the centre of its coordination shell. The preferences for parallel configuration and concerted rotation, with the polarisation changes, are consistent with ferroelectricity in the material, and indicate that this polarisation is governed by methylammonium orientational correlations. We show that the field due to this polarisation is strong enough to screen the field hindering charge transport, and find this screening field in agreement with experiment. We examine two possible mechanisms for the effect of methylammonium ion rotation on photovoltaic performance. One is that rearrangement of methylammoniums promotes the creation and transport of charge carriers. Some effective masses change greatly, but changes in band structure with methylammonium rotation are not large enough to explain current-voltage hysteresis behaviour. The second possible mechanism is that polarization screens the hindering electric field, which arises from charge accumulation in the transport layers. Polarization changes on methylammonium rotation favour this second mechanism, suggesting that collective reorientation of methylammonium ions in the bulk crystal are in significant part responsible for the hysteresis and power conversion characteristics of CH3NH3PbI3 photovoltaic cells.

  19. A landscape ecology approach to assessing development impacts in the tropics: A geothermal energy example in Hawaii

    Science.gov (United States)

    Griffith, J.A.; Trettin, C.C.; O'Neill, R. V.

    2002-01-01

    Geographic information systems (GIS) are increasingly being used in environmental impact assessments (EIA) because GIS is useful for analysing spatial impacts of various development scenarios. Spatially representing these impacts provides another tool for landscape ecology in environmental and geographical investigations by facilitating analysis of the effects of landscape patterns on ecological processes and examining change over time. Landscape ecological principles are applied in this study to a hypothetical geothermal development project on the Island of Hawaii. Some common landscape pattern metrics were used to analyse dispersed versus condensed development scenarios and their effect on landscape pattern. Indices of fragmentation and patch shape did not appreciably change with additional development. The amount of forest to open edge, however, greatly increased with the dispersed development scenario. In addition, landscape metrics showed that a human disturbance had a greater simplifying effect on patch shape and also increased fragmentation than a natural disturbance. The use of these landscape pattern metrics can advance the methodology of applying GIS to EIA.

  20. The significance of the amorphous potential energy landscape for dictating glassy dynamics and driving solid-state crystallisation.

    Science.gov (United States)

    Ruggiero, Michael T; Krynski, Marcin; Kissi, Eric Ofosu; Sibik, Juraj; Markl, Daniel; Tan, Nicholas Y; Arslanov, Denis; van der Zande, Wim; Redlich, Britta; Korter, Timothy M; Grohganz, Holger; Löbmann, Korbinian; Rades, Thomas; Elliott, Stephen R; Zeitler, J Axel

    2017-11-15

    The fundamental origins surrounding the dynamics of disordered solids near their characteristic glass transitions continue to be fiercely debated, even though a vast number of materials can form amorphous solids, including small-molecule organic, inorganic, covalent, metallic, and even large biological systems. The glass-transition temperature, T g , can be readily detected by a diverse set of techniques, but given that these measurement modalities probe vastly different processes, there has been significant debate regarding the question of why T g can be detected across all of them. Here we show clear experimental and computational evidence in support of a theory that proposes that the shape and structure of the potential-energy surface (PES) is the fundamental factor underlying the glass-transition processes, regardless of the frequency that experimental methods probe. Whilst this has been proposed previously, we demonstrate, using ab initio molecular-dynamics (AIMD) simulations, that it is of critical importance to carefully consider the complete PES - both the intra-molecular and inter-molecular features - in order to fully understand the entire range of atomic-dynamical processes in disordered solids. Finally, we show that it is possible to utilise this dependence to directly manipulate and harness amorphous dynamics in order to control the behaviour of such solids by using high-powered terahertz pulses to induce crystallisation and preferential crystal-polymorph growth in glasses. Combined, these findings provide compelling evidence that the PES landscape, and the corresponding energy barriers, are the ultimate controlling feature behind the atomic and molecular dynamics of disordered solids, regardless of the frequency at which they occur.

  1. Landscape Ecology

    DEFF Research Database (Denmark)

    Christensen, Andreas Aagaard; Brandt, Jesper; Svenningsen, Stig Roar

    2017-01-01

    Landscape ecology is an interdisciplinary field of research and practice that deals with the mutual association between the spatial configuration and ecological functioning of landscapes, exploring and describing processes involved in the differentiation of spaces within landscapes......, and the ecological significance of the patterns which are generated by such processes. In landscape ecology, perspectives drawn from existing academic disciplines are integrated based on a common, spatially explicit mode of analysis developed from classical holistic geography, emphasizing spatial and landscape...... pattern analysis and ecological interaction of land units. The landscape is seen as a holon: an assemblage of interrelated phenomena, both cultural and biophysical, that together form a complex whole. Enduring challenges to landscape ecology include the need to develop a systematic approach able...

  2. Information resources in high-energy physics. Surveying the present landscape and charting the future course

    Energy Technology Data Exchange (ETDEWEB)

    Gentil-Beccot, A.; Mele, S. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Holtkamp, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); O' Connell, H.B. [Fermi National Accelerator Lab., Batavia, IL (United States); Brooks, T.C. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

    2008-04-15

    Access to previous results is of paramount importance in the scientific process. Recent progress in information management focuses on building e-infrastructures for the optimization of the research workflow, through both policy-driven and user-pulled dynamics. For decades, High-Energy Physics (HEP) has pioneered innovative solutions in the eld of infor- mation management and dissemination. In light of a transforming information environment, it is important to assess the current usage of information resources by researchers and HEP provides a unique test-bed for this assessment. A survey of about 10% of practitioners in the eld reveals usage trends and information needs. Community-based services, such as the pioneering arXiv and SPIRES systems, largely answer the need of the scientists, with a limited but increasing fraction of younger users relying on Google. Commercial services offered by publishers or database vendors are essentially unused in the eld. The survey o ers an in- sight into the most important features that users require to optimize their research workflow. These results inform the future evolution of information management in HEP and, as these researchers are traditionally 'early adopters' of innovation in scholarly communication, can inspire developments of disciplinary repositories serving other communities. (orig.)

  3. Tailoring the Energy Landscape in Quasi-2D Halide Perovskites Enables Efficient Green-Light Emission

    KAUST Repository

    Quan, Li Na; Zhao, Yongbiao; Garcí a de Arquer, F. Pelayo; Sabatini, Randy; Walters, Grant; Voznyy, Oleksandr; Comin, Riccardo; Li, Yiying; Fan, James Z.; Tan, Hairen; Pan, Jun; Yuan, Mingjian; Bakr, Osman; Lu, Zhenghong; Kim, Dong Ha; Sargent, Edward H.

    2017-01-01

    Organo-metal halide perovskites are a promising platform for optoelectronic applications in view of their excellent charge-transport and bandgap tunability. However, their low photoluminescence quantum efficiencies, especially in low-excitation regimes, limit their efficiency for light emission. Consequently, perovskite light-emitting devices are operated under high injection, a regime under which the materials have so far been unstable. Here we show that, by concentrating photoexcited states into a small subpopulation of radiative domains, one can achieve a high quantum yield, even at low excitation intensities. We tailor the composition of quasi-2D perovskites to direct the energy transfer into the lowest-bandgap minority phase and to do so faster than it is lost to nonradiative centers. The new material exhibits 60% photoluminescence quantum yield at excitation intensities as low as 1.8 mW/cm2, yielding a ratio of quantum yield to excitation intensity of 0.3 cm2/mW; this represents a decrease of 2 orders of magnitude in the excitation power required to reach high efficiency compared with the best prior reports. Using this strategy, we report light-emitting diodes with external quantum efficiencies of 7.4% and a high luminescence of 8400 cd/m2.

  4. Ionic Strength Modulation of the Free Energy Landscape of Aβ40 Peptide Fibril Formation.

    Science.gov (United States)

    Abelein, Axel; Jarvet, Jüri; Barth, Andreas; Gräslund, Astrid; Danielsson, Jens

    2016-06-01

    Protein misfolding and formation of cross-β structured amyloid fibrils are linked to many neurodegenerative disorders. Although recently developed quantitative approaches have started to reveal the molecular nature of self-assembly and fibril formation of proteins and peptides, it is yet unclear how these self-organization events are precisely modulated by microenvironmental factors, which are known to strongly affect the macroscopic aggregation properties. Here, we characterize the explicit effect of ionic strength on the microscopic aggregation rates of amyloid β peptide (Aβ40) self-association, implicated in Alzheimer's disease. We found that physiological ionic strength accelerates Aβ40 aggregation kinetics by promoting surface-catalyzed secondary nucleation reactions. This promoted catalytic effect can be assigned to shielding of electrostatic repulsion between monomers on the fibril surface or between the fibril surface itself and monomeric peptides. Furthermore, we observe the formation of two different β-structured states with similar but distinct spectroscopic features, which can be assigned to an off-pathway immature state (Fβ*) and a mature stable state (Fβ), where salt favors formation of the Fβ fibril morphology. Addition of salt to preformed Fβ* accelerates transition to Fβ, underlining the dynamic nature of Aβ40 fibrils in solution. On the basis of these results we suggest a model where salt decreases the free-energy barrier for Aβ40 folding to the Fβ state, favoring the buildup of the mature fibril morphology while omitting competing, energetically less favorable structural states.

  5. Information resources in high-energy physics. Surveying the present landscape and charting the future course

    International Nuclear Information System (INIS)

    Gentil-Beccot, A.; Mele, S.; Holtkamp, A.; O'Connell, H.B.; Brooks, T.C.

    2008-04-01

    Access to previous results is of paramount importance in the scientific process. Recent progress in information management focuses on building e-infrastructures for the optimization of the research workflow, through both policy-driven and user-pulled dynamics. For decades, High-Energy Physics (HEP) has pioneered innovative solutions in the eld of infor- mation management and dissemination. In light of a transforming information environment, it is important to assess the current usage of information resources by researchers and HEP provides a unique test-bed for this assessment. A survey of about 10% of practitioners in the eld reveals usage trends and information needs. Community-based services, such as the pioneering arXiv and SPIRES systems, largely answer the need of the scientists, with a limited but increasing fraction of younger users relying on Google. Commercial services offered by publishers or database vendors are essentially unused in the eld. The survey o ers an in- sight into the most important features that users require to optimize their research workflow. These results inform the future evolution of information management in HEP and, as these researchers are traditionally ''early adopters'' of innovation in scholarly communication, can inspire developments of disciplinary repositories serving other communities. (orig.)

  6. Information resources in high-energy physics. Surveying the present landscape and charting the future course

    Energy Technology Data Exchange (ETDEWEB)

    Gentil-Beccot, A; Mele, S [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Holtkamp, A [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); O' Connell, H B [Fermi National Accelerator Lab., Batavia, IL (United States); Brooks, T C [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

    2008-04-15

    Access to previous results is of paramount importance in the scientific process. Recent progress in information management focuses on building e-infrastructures for the optimization of the research workflow, through both policy-driven and user-pulled dynamics. For decades, High-Energy Physics (HEP) has pioneered innovative solutions in the eld of infor- mation management and dissemination. In light of a transforming information environment, it is important to assess the current usage of information resources by researchers and HEP provides a unique test-bed for this assessment. A survey of about 10% of practitioners in the eld reveals usage trends and information needs. Community-based services, such as the pioneering arXiv and SPIRES systems, largely answer the need of the scientists, with a limited but increasing fraction of younger users relying on Google. Commercial services offered by publishers or database vendors are essentially unused in the eld. The survey o ers an in- sight into the most important features that users require to optimize their research workflow. These results inform the future evolution of information management in HEP and, as these researchers are traditionally 'early adopters' of innovation in scholarly communication, can inspire developments of disciplinary repositories serving other communities. (orig.)

  7. Information Resources in High-Energy Physics: Surveying the Present Landscape and Charting the Future Course

    Energy Technology Data Exchange (ETDEWEB)

    Gentil-Beccot, Anne; Mele, Salvatore; Holtkamp, Annette; O' Connell, Heath B.; Brooks, Travis C.

    2008-04-22

    Access to previous results is of paramount importance in the scientific process. Recent progress in information management focuses on building e-infrastructures for the optimization of the research workflow, through both policy-driven and user-pulled dynamics. For decades, High-Energy Physics (HEP) has pioneered innovative solutions in the field of information management and dissemination. In light of a transforming information environment, it is important to assess the current usage of information resources by researchers and HEP provides a unique test-bed for this assessment. A survey of about 10% of practitioners in the field reveals usage trends and information needs. Community-based services, such as the pioneering arXiv and SPIRES systems, largely answer the need of the scientists, with a limited but increasing fraction of younger users relying on Google. Commercial services offered by publishers or database vendors are essentially unused in the field. The survey offers an insight into the most important features that users require to optimize their research workflow. These results inform the future evolution of information management in HEP and, as these researchers are traditionally 'early adopters' of innovation in scholarly communication, can inspire developments of disciplinary repositories serving other communities.

  8. Tailoring the Energy Landscape in Quasi-2D Halide Perovskites Enables Efficient Green-Light Emission

    KAUST Repository

    Quan, Li Na

    2017-05-10

    Organo-metal halide perovskites are a promising platform for optoelectronic applications in view of their excellent charge-transport and bandgap tunability. However, their low photoluminescence quantum efficiencies, especially in low-excitation regimes, limit their efficiency for light emission. Consequently, perovskite light-emitting devices are operated under high injection, a regime under which the materials have so far been unstable. Here we show that, by concentrating photoexcited states into a small subpopulation of radiative domains, one can achieve a high quantum yield, even at low excitation intensities. We tailor the composition of quasi-2D perovskites to direct the energy transfer into the lowest-bandgap minority phase and to do so faster than it is lost to nonradiative centers. The new material exhibits 60% photoluminescence quantum yield at excitation intensities as low as 1.8 mW/cm2, yielding a ratio of quantum yield to excitation intensity of 0.3 cm2/mW; this represents a decrease of 2 orders of magnitude in the excitation power required to reach high efficiency compared with the best prior reports. Using this strategy, we report light-emitting diodes with external quantum efficiencies of 7.4% and a high luminescence of 8400 cd/m2.

  9. Information Resources in High-Energy Physics: Surveying the Present Landscape and Charting the Future Course

    International Nuclear Information System (INIS)

    Gentil-Beccot, Anne; Mele, Salvatore; Holtkamp, Annette; O'Connell, Heath B.; Brooks, Travis C.

    2008-01-01

    Access to previous results is of paramount importance in the scientific process. Recent progress in information management focuses on building e-infrastructures for the optimization of the research workflow, through both policy-driven and user-pulled dynamics. For decades, High-Energy Physics (HEP) has pioneered innovative solutions in the field of information management and dissemination. In light of a transforming information environment, it is important to assess the current usage of information resources by researchers and HEP provides a unique test-bed for this assessment. A survey of about 10% of practitioners in the field reveals usage trends and information needs. Community-based services, such as the pioneering arXiv and SPIRES systems, largely answer the need of the scientists, with a limited but increasing fraction of younger users relying on Google. Commercial services offered by publishers or database vendors are essentially unused in the field. The survey offers an insight into the most important features that users require to optimize their research workflow. These results inform the future evolution of information management in HEP and, as these researchers are traditionally 'early adopters' of innovation in scholarly communication, can inspire developments of disciplinary repositories serving other communities

  10. The importance of on-site evaluation for placing renewable energy in the landscape: A case study of the Búrfell wind farm (Iceland)

    Czech Academy of Sciences Publication Activity Database

    Frantál, Bohumil; Bevk, T.; van Veelen, B.; Hărmănescu, M.; Benediktsson, K.

    2017-01-01

    Roč. 25, č. 4 (2017), s. 234-247 ISSN 1210-8812 R&D Projects: GA ČR GA16-04483S Institutional support: RVO:68145535 Keywords : wind energy * landscape perception * Iceland Subject RIV: DE - Earth Magnetism, Geodesy, Geography OBOR OECD: Environmental sciences (social aspects) Impact factor: 2.149, year: 2016 http://www.geonika.cz/EN/research/ENMGRClanky/2017_4_FRANT%C3%81L.pdf

  11. Landscape Ecology

    DEFF Research Database (Denmark)

    Christensen, Andreas Aagaard; Brandt, Jesper; Svenningsen, Stig Roar

    2017-01-01

    , and the ecological significance of the patterns which are generated by such processes. In landscape ecology, perspectives drawn from existing academic disciplines are integrated based on a common, spatially explicit mode of analysis developed from classical holistic geography, emphasizing spatial and landscape...... to translate positivist readings of the environment and hermeneutical perspectives on socioecological interaction into a common framework or terminology....

  12. Land-Sparing Opportunities for Solar Energy Development in Agricultural Landscapes: A Case Study of the Great Central Valley, CA, United States.

    Science.gov (United States)

    Hoffacker, Madison K; Allen, Michael F; Hernandez, Rebecca R

    2017-12-19

    Land-cover change from energy development, including solar energy, presents trade-offs for land used for the production of food and the conservation of ecosystems. Solar energy plays a critical role in contributing to the alternative energy mix to mitigate climate change and meet policy milestones; however, the extent that solar energy development on nonconventional surfaces can mitigate land scarcity is understudied. Here, we evaluate the land sparing potential of solar energy development across four nonconventional land-cover types: the built environment, salt-affected land, contaminated land, and water reservoirs (as floatovoltaics), within the Great Central Valley (CV, CA), a globally significant agricultural region where land for food production, urban development, and conservation collide. Furthermore, we calculate the technical potential (TWh year -1 ) of these land sparing sites and test the degree to which projected electricity needs for the state of California can be met therein. In total, the CV encompasses 15% of CA, 8415 km 2 of which was identified as potentially land-sparing for solar energy development. These areas comprise a capacity-based energy potential of at least 17 348 TWh year -1 for photovoltaic (PV) and 2213 TWh year -1 for concentrating solar power (CSP). Accounting for technology efficiencies, this exceeds California's 2025 projected electricity demands up to 13 and 2 times for PV and CSP, respectively. Our study underscores the potential of strategic renewable energy siting to mitigate environmental trade-offs typically coupled with energy sprawl in agricultural landscapes.

  13. RAAAF's office landscape The End of Sitting : Energy expenditure and temporary comfort when working in non-sitting postures

    NARCIS (Netherlands)

    Caljouw, Simone R.; de Vries, Rutger; Withagen, Rob

    2017-01-01

    An earlier study suggested that the activity-inviting office landscape called "The End of Sitting", designed by Rietveld Architecture Art Affordances (RAAAF), should be considered as an alternative working environment to prevent sedentary behavior. The End of Sitting lacks chairs and tables but

  14. Shared Solar: Current Landscape, Market Potential, and the Impact of Federal Securities Regulation; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-05-27

    This presentation provides a high-level overview of the current U.S. shared solar landscape, the impact that a given shared solar program's structure has on requiring federal securities oversight, as well as an estimate of market potential for U.S. shared solar deployment.

  15. Desafiando o campo literário: Bufólicas e as estratégias de produção da crença em Hilda Hilst

    Directory of Open Access Journals (Sweden)

    Clovis Carvalho Britto

    2016-01-01

    Full Text Available El artículo analiza las estrategias de producción de creencia en Hilda Hilst (1930-2004 a través de las tensiones generadas por Bufólicas (1992 en el campo literario brasilero. Basado en referencias a Pierre Bourdieu, el articulo pone de relieve cómo la escritora promueve medios en favor de su distinción en ese espacio social al establecer un proyecto basado en la obscenidad, la risa y una fuerte crítica del mercado editorial. Con este fin, investiga cómo el libro consistió en un proyecto político, dirigiendo la producción de repertorios específicos acerca de Hilst en el mercado de bienes simbólicos, y al re-actualizar y ritualizar versiones construidas por la autora y por otros agentes.

  16. Industrious Landscaping

    DEFF Research Database (Denmark)

    Brichet, Nathalia Sofie; Hastrup, Frida

    2018-01-01

    This article has a twofold ambition. It offers a history of landscaping at Søby brown coal beds—a former mining site in western Denmark—and a methodological discussion of how to write such a study. Exploring this specific industrial landscape through a series of projects that have made different...... natural resources appear, we show that even what is recognized as resources shifts over time according to radically different and unpredictable agendas. This indicates that the Søby landscape is fundamentally volatile, as its resourcefulness has been seen interchangeably to shift between the brown coal...... business, inexpensive estates for practically savvy people, pasture for grazing, and recreational forest, among other things. We discuss these rifts in landscape history, motivated by what we refer to as industriousness, to show that, at sites such as Søby, both natural resources and historical...

  17. Electromagnetic Landscape

    DEFF Research Database (Denmark)

    Cermak, Daniel; Okutsu, Ayaka; Jørgensen, Stina Marie Hasse

    2015-01-01

    Daniel Cermak-Sassenrath, Ayaka Okutsu, Stina Hasse. Electromagnetic Landscape - In-between Signal, Noise and Environment. Installation and artist talk. 21th International Symposium on Electronic Art (ISEA) 2015, Vancouver, CAN, Aug 14-18, 2015.......Daniel Cermak-Sassenrath, Ayaka Okutsu, Stina Hasse. Electromagnetic Landscape - In-between Signal, Noise and Environment. Installation and artist talk. 21th International Symposium on Electronic Art (ISEA) 2015, Vancouver, CAN, Aug 14-18, 2015....

  18. Nordic Landscape

    DEFF Research Database (Denmark)

    Hjortshøj, Rasmus

    2017-01-01

    This Box Set NORDIC LANDSCAPE presents Nordic Territories, a project by Rasmus Hjortshøj, exploring the man-made landscapes of the coastal territories and the entanglement of society and nature in times where it is no longer merely mankind subjected to nature, but where nature is equally being...... territories is not only their transient nature, but also the warm currents of the Gulf Stream making these northern shorelines habitable for human settlements....

  19. Changing Landscapes, Changing Landscape's Story

    Czech Academy of Sciences Publication Activity Database

    Lapka, Miloslav; Cudlínová, Eva

    2003-01-01

    Roč. 28, č. 3 (2003), s. 323-328 ISSN 0142-6397. [Symposium on Sustainable Landscapes in an Enlarged Europe. Nové Hrady, 12.09.2001-14.09.2001] R&D Projects: GA MŠk ME 530 Grant - others:GA-(XE) QLK5-CT-2000-01211-SPRITE Institutional research plan: CEZ:AV0Z5039906 Keywords : Landscape stability * narrative approach * socio-economic typology Subject RIV: DO - Wilderness Conservation

  20. Evidence and opportunities for integrating landscape ecology into natural resource planning across multiple-use landscapes

    Science.gov (United States)

    Trammel, E. Jamie; Carter, Sarah; Haby, Travis S.; Taylor, Jason J.

    2018-01-01

    Enhancing natural resource management has been a focus of landscape ecology since its inception, but numerous authors argue that landscape ecology has not yet been effective in achieving the underlying goal of planning and designing sustainable landscapes. We developed nine questions reflecting the application of fundamental research topics in landscape ecology to the landscape planning process and reviewed two recent landscape-scale plans in western North America for evidence of these concepts in plan decisions. Both plans considered multiple resources, uses, and values, including energy development, recreation, conservation, and protection of cultural and historic resources. We found that land use change and multiscale perspectives of resource uses and values were very often apparent in planning decisions. Pattern-process relationships, connectivity and fragmentation, ecosystem services, landscape history, and climate change were reflected less frequently. Landscape sustainability was considered only once in the 295 decisions reviewed, and outputs of landscape models were not referenced. We suggest six actionable opportunities for further integrating landscape ecology concepts into landscape planning efforts: 1) use landscape sustainability as an overarching goal, 2) adopt a broad ecosystem services framework, 3) explore the role of landscape history more comprehensively, 4) regularly consider and accommodate potential effects of climate change, 5) use landscape models to support plan decisions, and 6) promote a greater presence of landscape ecologists within agencies that manage large land bases and encourage active involvement in agency planning efforts. Together these actions may improve the defensibility, durability, and sustainability of landscape plan decisions.

  1. Free-Energy Landscape of Reverse tRNA Translocation through the Ribosome Analyzed by Electron Microscopy Density Maps and Molecular Dynamics Simulations

    Science.gov (United States)

    Ishida, Hisashi; Matsumoto, Atsushi

    2014-01-01

    To understand the mechanism of reverse tRNA translocation in the ribosome, all-atom molecular dynamics simulations of the ribosome-tRNAs-mRNA-EFG complex were performed. The complex at the post-translocational state was directed towards the translocational and pre-translocational states by fitting the complex into cryo-EM density maps. Between a series of the fitting simulations, umbrella sampling simulations were performed to obtain the free-energy landscape. Multistep structural changes, such as a ratchet-like motion and rotation of the head of the small subunit were observed. The free-energy landscape showed that there were two main free-energy barriers: one between the post-translocational and intermediate states, and the other between the pre-translocational and intermediate states. The former corresponded to a clockwise rotation, which was coupled to the movement of P-tRNA over the P/E-gate made of G1338, A1339 and A790 in the small subunit. The latter corresponded to an anticlockwise rotation of the head, which was coupled to the location of the two tRNAs in the hybrid state. This indicates that the coupled motion of the head rotation and tRNA translocation plays an important role in opening and closing of the P/E-gate during the ratchet-like movement in the ribosome. Conformational change of EF-G was interpreted to be the result of the combination of the external motion by L12 around an axis passing near the sarcin-ricin loop, and internal hinge-bending motion. These motions contributed to the movement of domain IV of EF-G to maintain its interaction with A/P-tRNA. PMID:24999999

  2. Free-energy landscape of reverse tRNA translocation through the ribosome analyzed by electron microscopy density maps and molecular dynamics simulations.

    Directory of Open Access Journals (Sweden)

    Hisashi Ishida

    Full Text Available To understand the mechanism of reverse tRNA translocation in the ribosome, all-atom molecular dynamics simulations of the ribosome-tRNAs-mRNA-EFG complex were performed. The complex at the post-translocational state was directed towards the translocational and pre-translocational states by fitting the complex into cryo-EM density maps. Between a series of the fitting simulations, umbrella sampling simulations were performed to obtain the free-energy landscape. Multistep structural changes, such as a ratchet-like motion and rotation of the head of the small subunit were observed. The free-energy landscape showed that there were two main free-energy barriers: one between the post-translocational and intermediate states, and the other between the pre-translocational and intermediate states. The former corresponded to a clockwise rotation, which was coupled to the movement of P-tRNA over the P/E-gate made of G1338, A1339 and A790 in the small subunit. The latter corresponded to an anticlockwise rotation of the head, which was coupled to the location of the two tRNAs in the hybrid state. This indicates that the coupled motion of the head rotation and tRNA translocation plays an important role in opening and closing of the P/E-gate during the ratchet-like movement in the ribosome. Conformational change of EF-G was interpreted to be the result of the combination of the external motion by L12 around an axis passing near the sarcin-ricin loop, and internal hinge-bending motion. These motions contributed to the movement of domain IV of EF-G to maintain its interaction with A/P-tRNA.

  3. Contemporary danish landscape research

    DEFF Research Database (Denmark)

    Vejre, H.; Brandt, J.

    2004-01-01

    Danish landscape research blossomed during the 1990’ies thanks to several transdisciplinary research programmes involving several institutions. The main themes of the programmes encompassed Landscape change, landscape and biological diversity, nature and landscape management, use and monitoring...

  4. Electromagnetic Landscape

    DEFF Research Database (Denmark)

    Cermak, Daniel; Okutsu, Ayaka; Hasse, Stina

    2015-01-01

    Electromagnetic Landscape demonstrates in direct, tangible and immediate ways effects of the disruption of the familiar. An ubiquitous technological medium, FM radio, is turned into an alien and unfamiliar one. Audience participation, the environment, radio signals and noise create a site...

  5. Changing Landscape

    DEFF Research Database (Denmark)

    Tunby Gulbrandsen, Ib; Kamstrup, Andreas; Koed Madsen, Anders

    with an analysis of the changing organizational landscape created by new ICT’s like Google, Facebook, Wikipedia, iPods, smart phones and Wi-Fi. Based on five netno- and ethno-graphic investigations of the intertwinement of ICT’s and organizational work, we point to three features that have changed the scene: new...

  6. Disposable Landscapes

    Science.gov (United States)

    Kevin T. Smith

    2008-01-01

    Whether we are a traditionalist or on the cutting edge of landscape care, we need to take a deep breath and think about what we are trying to achieve, before we select a specific treatment or practice for tree care. We should measure that treatment or practice against what we know about the tree system. I say "system" because the recent years of Modern...

  7. Ecological Functions of Landscapes

    Science.gov (United States)

    Kiryushin, V. I.

    2018-01-01

    Ecological functions of landscapes are considered a system of processes ensuring the development, preservation, and evolution of ecosystems and the biosphere as a whole. The concept of biogeocenosis can be considered a model that integrates biotic and environmental functions. The most general biogeocenotic functions specify the biodiversity, biotic links, self-organization, and evolution of ecosystems. Close interaction between biocenosis and the biotope (ecotope) is ensured by the continuous exchange of matter, energy, and information. Ecotope determines the biocenosis. The group of ecotopic functions includes atmospheric (gas exchange, heat exchange, hydroatmospheric, climate-forming), lithospheric (geodynamic, geophysical, and geochemical), hydrologic and hydrogeologic functions of landscape and ecotopic functions of soils. Bioecological functions emerge as a result of the biotope and ecotope interaction; these are the bioproductive, destructive, organoaccumulative, biochemical (gas, concentration, redox, biochemical, biopedological), pedogenetic, and energy functions

  8. The French market of wind energy and its perspectives. Which evolution for the competition landscape in a disrupting regulatory context?

    International Nuclear Information System (INIS)

    2010-11-01

    This article presents the content of a market study which aimed at providing an overview of the development of wind energy in France after market lift-off, at assessing the influence of Grenelle II on this sector, at assessing the competitiveness of wind energy with respect to other production sources, and at analysing strategies of equipment manufacturers and operators on a market where competitive positions are from being fixed. The report proposes an overview of the French wind energy market (legal context, growth dynamics, market valorisation, cost structure and profitability, support measures), analyses the positions and challenges of wind turbine manufacturers (the front end of the sector) and of wind farm developers and operators (the back end of the sector). Several manufacturers (Areva, Enercon, Gamesa, GE Energy, Nordex, REpower, Siemens and Vestas) and developers and operators (Boralex, EDF Energies Nouvelles, EDP Renovavels, Eolfi, GDF Suez, Iberdrola Renovables, Poweo, Theolia) have been analysed

  9. A study of the deep structure of the energy landscape of glassy polystyrene: the exponential distribution of the energy barriers revealed by high-field electron spin resonance spectroscopy

    International Nuclear Information System (INIS)

    Bercu, V; Martinelli, M; Massa, C A; Pardi, L A; Leporini, D

    2004-01-01

    The reorientation of one small paramagnetic molecule (spin probe) in glassy polystyrene (PS) is studied by high-field electron spin resonance spectroscopy at two different Larmor frequencies (190 and 285 GHz). The exponential distribution of the energy barriers for the rotational motion of the spin probe is unambiguously evidenced at both 240 and 270 K. The same shape for the distribution of the energy barriers of PS was evidenced by the master curves provided by previous mechanical and light scattering studies. The breadth of the energy barrier distribution of the spin probe is in the range of the estimates of the breadth of the PS energy barrier distribution. The evidence that the deep structure of the energy landscape of PS exhibits the exponential shape of the energy barrier distribution agrees with the results from extreme-value statistics (Bouchaud and Mezard 1997 J. Phys. A: Math. Gen. 30 7997) and the trap model by Bouchaud and co-workers (1996 J. Phys. A: Math. Gen. 29 3847, 2001 Phys. Rev. B 64 104417). (letter to the editor)

  10. An approach to costs and energy consumption in private urban Spanish Mediterranean landscapes from a simplified model in sprinkle irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Arbat, G.; Pujol, J.; Pelegri, M.; Puig-Bargues, J.; Duran-Ros, M.; Ramirez de Cartagena, F.

    2013-05-01

    The number of private gardens has increased in recent years, creating a more pleasant urban model, but not without having an environmental impact, including increased energy consumption, which is the focus of this study. The estimation of costs and energy consumption for the generic typology of private urban gardens is based on two simplifying assumptions: square geometry with surface areas from 25 to 500 m{sup 2} and hydraulic design with a single pipe. In total, eight sprinkler models have been considered, along with their possible working pressures, and 31 pumping units grouped into 5 series that adequately cover the range of required flow rates and pressures, resulting in 495 hydraulic designs repeated for two climatically different locations in the Spanish Mediterranean area (Girona and Elche). Mean total irrigation costs for the locality with lower water needs (Girona) and greater needs (Elche) were {epsilon} 2,974 ha{sup -}1 yr-1 and {epsilon}3,383 ha{sup -}1 yr{sup -}1, respectively. Energy costs accounted for 11.4% of the total cost for the first location, and 23.0% for the second. While a suitable choice of the hydraulic elements of the setup is essential, as it may provide average energy savings of 77%, due to the low energy cost in relation to the cost of installation, the potential energy savings do not constitute a significant incentive for the irrigation system design. The low efficiency of the pumping units used in this type of garden is the biggest obstacle and constraint to achieving a high quality energy solution. (Author) 32 refs.

  11. An approach to costs and energy consumption in private urban Spanish Mediterranean landscapes from a simplified model in sprinkle irrigation

    Directory of Open Access Journals (Sweden)

    G. Arbat

    2013-02-01

    Full Text Available The number of private gardens has increased in recent years, creating a more pleasant urban model, but not without having an environmental impact, including increased energy consumption, which is the focus of this study. The estimation of costs and energy consumption for the generic typology of private urban gardens is based on two simplifying assumptions: square geometry with surface areas from 25 to 500 m2 and hydraulic design with a single pipe. In total, eight sprinkler models have been considered, along with their possible working pressures, and 31 pumping units grouped into 5 series that adequately cover the range of required flow rates and pressures, resulting in 495 hydraulic designs repeated for two climatically different locations in the Spanish Mediterranean area (Girona and Elche. Mean total irrigation costs for the locality with lower water needs (Girona and greater needs (Elche were € 2,974 ha-1 yr-1 and € 3,383 ha-1 yr-1, respectively. Energy costs accounted for 11.4% of the total cost for the first location, and 23.0% for the second. While a suitable choice of the hydraulic elements of the setup is essential, as it may provide average energy savings of 77%, due to the low energy cost in relation to the cost of installation, the potential energy savings do not constitute a significant incentive for the irrigation system design. The low efficiency of the pumping units used in this type of garden is the biggest obstacle and constraint to achieving a high quality energy solution.

  12. Potential Energy Landscape of the Liquid-Liquid Phase Transition in Water and the transformation between Low-Density and High-Density Amorphous Ice

    Science.gov (United States)

    Giovambattista, N.; Sciortino, F.; Starr, F. W.; Poole, P. H.

    The potential energy landscape (PEL) formalism is a valuable approach within statistical mechanics for describing supercooled liquids and glasses. We use the PEL formalism and computer simulations to study the transformation between low-density (LDL) and high-density liquid (HDL) water, and between low-density (LDA) and high-density amorphous ice (HDA). We employ the ST2 water model that exhibits a LDL-HDL first-order phase transition and a sharp LDA-HDA transformation, as observed in experiments. Our results are consistent with the view that LDA and HDA configurations are associated with two distinct regions (megabasins) of the PEL that are separated by a potential energy barrier. At higher temperature, we find that LDL configurations are located in the same megabasin as LDA, and that HDL configurations are located in the same megabasin as HDA. We show that the pressure-induced LDL-HDL and LDA-HDA transformations occur along paths that interconnect these two megabasins, but that the path followed by the liquid and the amorphous ice differ. We also study the liquid-to-ice-VII first-order phase transition. The PEL properties across this transition are qualitatively similar to the changes found during the LDA-HDA transformation, supporting the interpretation that the LDA-HDA transformation is a first-order-like phase transition between out-of-equilibrium states.

  13. Influence of sample preparation on the transformation of low-density to high-density amorphous ice: An explanation based on the potential energy landscape

    Science.gov (United States)

    Giovambattista, Nicolas; Starr, Francis W.; Poole, Peter H.

    2017-07-01

    Experiments and computer simulations of the transformations of amorphous ices display different behaviors depending on sample preparation methods and on the rates of change of temperature and pressure to which samples are subjected. In addition to these factors, simulation results also depend strongly on the chosen water model. Using computer simulations of the ST2 water model, we study how the sharpness of the compression-induced transition from low-density amorphous ice (LDA) to high-density amorphous ice (HDA) is influenced by the preparation of LDA. By studying LDA samples prepared using widely different procedures, we find that the sharpness of the LDA-to-HDA transformation is correlated with the depth of the initial LDA sample in the potential energy landscape (PEL), as characterized by the inherent structure energy. Our results show that the complex phenomenology of the amorphous ices reported in experiments and computer simulations can be understood and predicted in a unified way from knowledge of the PEL of the system.

  14. 储能技术研究景观辨识及演化探析%Identifying the Landscape and Its Evolution in Energy Storage Research

    Institute of Scientific and Technical Information of China (English)

    刘娜; 孙静林; 毛荐其

    2017-01-01

    This study seeks to integrate statistics, text mining, burst detecting and co-occurrence network visualiza-tion to identify the landscape and its evolution of energy storage research from a holistic perspective based on ar-ticles on physical, chemical, electromagnetic and phase change energy storage extracted from SCI-E and SSCI data-base between 1991 and 2015. A stability coefficient and an innovation coefficient are also defined to measure the stability evolution and innovation evolution of keywords co-occurrence networks in energy storage respectively. Our results indicate that the research in energy storage is highly-concentrated in key issues, hot topics are fly-wheel, lithium ion batteries, supercapacitors and phase change materials, and frontier topics are compressed air energy storage, energy storage, lithium ion batteries, thermal conductivity and thermal energy storage. We also find keywords co-occurrence networks expand significantly, knowledge structures evolve constantly and energy storage research is still in its innovation phase.%基于SCI-E及SSCI数据库,检索并提取1991—2015年间物理储能、化学储能、电磁储能和相变储能4大技术领域的论文数据,试图整合统计分析、文本挖掘、突现检测算法和共现网络可视化方法,旨在从整体视角实现对4大储能技术领域科学研究景观的辨识及演化探析.此外,还定义了稳定系数和创新系数,以测度储能关键词共现网络的稳定性演化和创新性演化.研究发现:储能领域的研究问题是高度集中的,"飞轮"、"锂离子电池"、"超级电容器"和"相变材料"是研究热点,"压缩空气储能"、"能源存储"、"锂离子电池"、"导热性"和"热发电"是研究前沿;储能关键词共现网络扩张明显,知识结构也不断演化,储能研究仍处于创新热络期.

  15. Cuban Landscapes

    DEFF Research Database (Denmark)

    Scarpaci, Joseph L.; Portela, Armando

    This accessible book offers a vivid geographic portrait of Cuba, exploring the island’s streetscapes, sugar cane fields, beaches, and rural settlements; its billboards, government buildings, and national landmarks. The authors illuminate how natural and built landscapes have shaped Cuban identity...... (cubanidad), and vice versa. They provide a unique perspective on Cuba’s distinct historical periods and political economies, from the colonial period through republicanism and today’s socialist era. Compelling topics include the legacies of slavery and the sugar industry, the past and future of urban...

  16. Characterization of the polymer energy landscape in polymer:fullerene bulk heterojunctions with pure and mixed phases

    KAUST Repository

    Sweetnam, Sean

    2014-10-08

    Theoretical and experimental studies suggest that energetic offsets between the charge transport energy levels in different morphological phases of polymer:fullerene bulk heterojunctions may improve charge separation and reduce recombination in polymer solar cells (PSCs). In this work, we use cyclic voltammetry, UV-vis absorption, and ultraviolet photoelectron spectroscopy to characterize hole energy levels in the polymer phases of polymer:fullerene bulk heterojunctions. We observe an energetic offset of up to 150 meV between amorphous and crystalline polymer due to bandgap widening associated primarily with changes in polymer conjugation length. We also observe an energetic offset of up to 350 meV associated with polymer:fullerene intermolecular interactions. The first effect has been widely observed, but the second effect is not always considered despite being larger in magnitude for some systems. These energy level shifts may play a major role in PSC performance and must be thoroughly characterized for a complete understanding of PSC function.

  17. AN EVALUATION OF THE SPATIAL DIMENSION OF LANDSCAPE ...

    African Journals Online (AJOL)

    Osondu

    2012-03-30

    Mar 30, 2012 ... with adequate landscaping, - using landscape elements, to create a ... air, water and energy cycles that replenish and rejuvenate ... First, using the street map of. Ogbomoso ... swimming pools, etc, were regarded as conscious.

  18. PESP Landscaping Initiative

    Science.gov (United States)

    Landscaping practices can positively or negatively affect local environments and human health. The Landscaping Initiative seeks to enhance benefits of landscaping while reducing need for pesticides, fertilizers, etc., by working with partners.

  19. Universal time-dependence of the mean-square displacement in extremely rugged energy landscapes with equal minima

    DEFF Research Database (Denmark)

    Dyre, Jeppe; Jacobsen, Jacob M.

    1995-01-01

    This paper presents a calculation of the time dependence of the mean-square displacement for symmetric random energy barrier hopping models at low temperatures, where the frequency dependence of the normalized diffusion constant D-tilde becomes universal, i.e., independent of the energy barrier...... probability distribution [J. C. Dyre, Phys. Rev. B 49, 11 709 (1994)]. The universal time dependence of the mean-square displacement is calculated from the effective medium approximation (EMA) universality equation, D-tilde lnD-tilde=s-tilde, where s-tilde is the dimensionless imaginary frequency, as well...... as for the approximation to the EMA universality equation D-tilde~=s-tilde/ln(1+s-tilde). At long times the universal mean-square displacement is linear in time, corresponding to ordinary diffusion, whereas the mean-square displacement at short times t in dimensionless units varies as 2/ln(t-1)....

  20. Landscape planning as a contribution to the assessment and finding of sites for energy facilities from an ecological and creative point of view

    International Nuclear Information System (INIS)

    Buchwald, K.

    1977-01-01

    The environmental agreeability examination through landscape planning in connection with the finding of sites for power stations and their integration into area planning is explained. The procedure of landscape planning for the assessment of power station sites is also presented. (RW) [de

  1. On the importance of a funneled energy landscape for the assembly and regulation of multidomain Src tyrosine kinases

    OpenAIRE

    Faraldo-Gómez, José D.; Roux, Benoît

    2007-01-01

    Regulation of signaling pathways in the cell often involves multidomain allosteric enzymes that are able to adopt alternate active or inactive conformations in response to specific stimuli. It is therefore of great interest to elucidate the energetic and structural determinants that govern the conformational plasticity of these proteins. In this study, free-energy computations have been used to address this fundamental question, focusing on one important family of signaling enzymes, the Src t...

  2. Enhancing the Simplified Surface Energy Balance (SSEB) Approach for Estimating Landscape ET: Validation with the METRIC model

    Science.gov (United States)

    Senay, Gabriel B.; Budde, Michael E.; Verdin, James P.

    2011-01-01

    Evapotranspiration (ET) can be derived from satellite data using surface energy balance principles. METRIC (Mapping EvapoTranspiration at high Resolution with Internalized Calibration) is one of the most widely used models available in the literature to estimate ET from satellite imagery. The Simplified Surface Energy Balance (SSEB) model is much easier and less expensive to implement. The main purpose of this research was to present an enhanced version of the Simplified Surface Energy Balance (SSEB) model and to evaluate its performance using the established METRIC model. In this study, SSEB and METRIC ET fractions were compared using 7 Landsat images acquired for south central Idaho during the 2003 growing season. The enhanced SSEB model compared well with the METRIC model output exhibiting an r2 improvement from 0.83 to 0.90 in less complex topography (elevation less than 2000 m) and with an improvement of r2 from 0.27 to 0.38 in more complex (mountain) areas with elevation greater than 2000 m. Independent evaluation showed that both models exhibited higher variation in complex topographic regions, although more with SSEB than with METRIC. The higher ET fraction variation in the complex mountainous regions highlighted the difficulty of capturing the radiation and heat transfer physics on steep slopes having variable aspect with the simple index model, and the need to conduct more research. However, the temporal consistency of the results suggests that the SSEB model can be used on a wide range of elevation (more successfully up 2000 m) to detect anomalies in space and time for water resources management and monitoring such as for drought early warning systems in data scarce regions. SSEB has a potential for operational agro-hydrologic applications to estimate ET with inputs of surface temperature, NDVI, DEM and reference ET.

  3. Micro-size cogeneration plants and virtual power plants. New energy landscapes; Mikro-KWK und virtuelle Kraftwerke. Neue Energielandschaften

    Energy Technology Data Exchange (ETDEWEB)

    Roon, Serafin von [Forschungsstelle fuer Energiewirtschaft e.V., Muenchen (Germany)

    2009-07-01

    Combined heat and power generation is an established technology. With micro-size cogeneration units, the technology is now available to private single or multiple dwellings and for decentral power supply of residential blocks. With the right political boundary conditions and integrated into virtual power stations, this is an option for enhanced use of renewable energy sources and for decentral, flexible and climate-friendly heat and power generation in buildings. Economic efficiency analyses by experts, high utilisation rates, innovative developments of the manufacturers and a positive public image are all in favour of a great future for micro-size cogeneration units. (orig.)

  4. On the importance of a funneled energy landscape for the assembly and regulation of multidomain Src tyrosine kinases.

    Science.gov (United States)

    Faraldo-Gómez, José D; Roux, Benoît

    2007-08-21

    Regulation of signaling pathways in the cell often involves multidomain allosteric enzymes that are able to adopt alternate active or inactive conformations in response to specific stimuli. It is therefore of great interest to elucidate the energetic and structural determinants that govern the conformational plasticity of these proteins. In this study, free-energy computations have been used to address this fundamental question, focusing on one important family of signaling enzymes, the Src tyrosine kinases. Inactivation of these enzymes depends on the formation of an assembly comprising a tandem of SH3 and SH2 modules alongside a catalytic domain. Activation results from the release of the SH3 and SH2 domains, which are then believed to be structurally uncoupled by virtue of a flexible peptide link. In contrast to this view, this analysis shows that inactivation depends critically on the intrinsic propensity of the SH3-SH2 tandem to adopt conformations that are conducive to the assembled inactive state, even when no interactions with the rest of the kinase are possible. This funneling of the available conformational space is encoded within the SH3-SH2 connector, which appears to have evolved to modulate the flexibility of the tandem in solution. To further substantiate this notion, we show how constitutively activating mutations in the SH3-SH2 connector shift the assembly equilibrium toward the disassembled, active state. Based on a similar analysis of several constructs of the kinase complex, we propose that assembly is characterized by the progressive optimization of the protein's conformational energy, with little or no energetic frustration.

  5. Stochastic Ratcheting on a Funneled Energy Landscape Is Necessary for Highly Efficient Contractility of Actomyosin Force Dipoles

    Science.gov (United States)

    Komianos, James E.; Papoian, Garegin A.

    2018-04-01

    Current understanding of how contractility emerges in disordered actomyosin networks of nonmuscle cells is still largely based on the intuition derived from earlier works on muscle contractility. In addition, in disordered networks, passive cross-linkers have been hypothesized to percolate force chains in the network, hence, establishing large-scale connectivity between local contractile clusters. This view, however, largely overlooks the free energy of cross-linker binding at the microscale, which, even in the absence of active fluctuations, provides a thermodynamic drive towards highly overlapping filamentous states. In this work, we use stochastic simulations and mean-field theory to shed light on the dynamics of a single actomyosin force dipole—a pair of antiparallel actin filaments interacting with active myosin II motors and passive cross-linkers. We first show that while passive cross-linking without motor activity can produce significant contraction between a pair of actin filaments, driven by thermodynamic favorability of cross-linker binding, a sharp onset of kinetic arrest exists at large cross-link binding energies, greatly diminishing the effectiveness of this contractility mechanism. Then, when considering an active force dipole containing nonmuscle myosin II, we find that cross-linkers can also serve as a structural ratchet when the motor dissociates stochastically from the actin filaments, resulting in significant force amplification when both molecules are present. Our results provide predictions of how actomyosin force dipoles behave at the molecular level with respect to filament boundary conditions, passive cross-linking, and motor activity, which can explicitly be tested using an optical trapping experiment.

  6. Stochastic Ratcheting on a Funneled Energy Landscape Is Necessary for Highly Efficient Contractility of Actomyosin Force Dipoles

    Directory of Open Access Journals (Sweden)

    James E. Komianos

    2018-04-01

    Full Text Available Current understanding of how contractility emerges in disordered actomyosin networks of nonmuscle cells is still largely based on the intuition derived from earlier works on muscle contractility. In addition, in disordered networks, passive cross-linkers have been hypothesized to percolate force chains in the network, hence, establishing large-scale connectivity between local contractile clusters. This view, however, largely overlooks the free energy of cross-linker binding at the microscale, which, even in the absence of active fluctuations, provides a thermodynamic drive towards highly overlapping filamentous states. In this work, we use stochastic simulations and mean-field theory to shed light on the dynamics of a single actomyosin force dipole—a pair of antiparallel actin filaments interacting with active myosin II motors and passive cross-linkers. We first show that while passive cross-linking without motor activity can produce significant contraction between a pair of actin filaments, driven by thermodynamic favorability of cross-linker binding, a sharp onset of kinetic arrest exists at large cross-link binding energies, greatly diminishing the effectiveness of this contractility mechanism. Then, when considering an active force dipole containing nonmuscle myosin II, we find that cross-linkers can also serve as a structural ratchet when the motor dissociates stochastically from the actin filaments, resulting in significant force amplification when both molecules are present. Our results provide predictions of how actomyosin force dipoles behave at the molecular level with respect to filament boundary conditions, passive cross-linking, and motor activity, which can explicitly be tested using an optical trapping experiment.

  7. Landscape encodings enhance optimization.

    Directory of Open Access Journals (Sweden)

    Konstantin Klemm

    Full Text Available Hard combinatorial optimization problems deal with the search for the minimum cost solutions (ground states of discrete systems under strong constraints. A transformation of state variables may enhance computational tractability. It has been argued that these state encodings are to be chosen invertible to retain the original size of the state space. Here we show how redundant non-invertible encodings enhance optimization by enriching the density of low-energy states. In addition, smooth landscapes may be established on encoded state spaces to guide local search dynamics towards the ground state.

  8. Landscape Encodings Enhance Optimization

    Science.gov (United States)

    Klemm, Konstantin; Mehta, Anita; Stadler, Peter F.

    2012-01-01

    Hard combinatorial optimization problems deal with the search for the minimum cost solutions (ground states) of discrete systems under strong constraints. A transformation of state variables may enhance computational tractability. It has been argued that these state encodings are to be chosen invertible to retain the original size of the state space. Here we show how redundant non-invertible encodings enhance optimization by enriching the density of low-energy states. In addition, smooth landscapes may be established on encoded state spaces to guide local search dynamics towards the ground state. PMID:22496860

  9. THE LANDSCAPE OF THE NEUTRINO MECHANISM OF CORE-COLLAPSE SUPERNOVAE: NEUTRON STAR AND BLACK HOLE MASS FUNCTIONS, EXPLOSION ENERGIES, AND NICKEL YIELDS

    International Nuclear Information System (INIS)

    Pejcha, Ondřej; Thompson, Todd A.

    2015-01-01

    If the neutrino luminosity from the proto-neutron star formed during a massive star core collapse exceeds a critical threshold, a supernova (SN) results. Using spherical quasi-static evolutionary sequences for hundreds of progenitors over a range of metallicities, we study how the explosion threshold maps onto observables, including the fraction of successful explosions, the neutron star (NS) and black hole (BH) mass functions, the explosion energies (E SN ) and nickel yields (M Ni ), and their mutual correlations. Successful explosions are intertwined with failures in a complex pattern that is not simply related to initial progenitor mass or compactness. We predict that progenitors with initial masses of 15 ± 1, 19 ± 1, and ∼21-26 M ☉ are most likely to form BHs, that the BH formation probability is non-zero at solar-metallicity and increases significantly at low metallicity, and that low luminosity, low Ni-yield SNe come from progenitors close to success/failure interfaces. We qualitatively reproduce the observed E SN -M Ni correlation, we predict a correlation between the mean and width of the NS mass and E SN distributions, and that the means of the NS and BH mass distributions are correlated. We show that the observed mean NS mass of ≅ 1.33 M ☉ implies that the successful explosion fraction is higher than 0.35. Overall, we show that the neutrino mechanism can in principle explain the observed properties of SNe and their compact objects. We argue that the rugged landscape of progenitors and outcomes mandates that SN theory should focus on reproducing the wide ranging distributions of observed SN properties

  10. Characterizing European cultural landscapes

    DEFF Research Database (Denmark)

    Tieskens, Koen F.; Schulp, Catharina J E; Levers, Christian

    2017-01-01

    intensification and land abandonment. To prevent the loss of cultural landscapes, knowledge on the location of different types of cultural landscapes is needed. In this paper, we present a characterization of European cultural landscapes based on the prevalence of three key dimensions of cultural landscapes......Almost all rural areas in Europe have been shaped or altered by humans and can be considered cultural landscapes, many of which now are considered to entail valuable cultural heritage. Current dynamics in land management have put cultural landscapes under a huge pressure of agricultural...... the three dimensions into a continuous “cultural landscape index” that allows for a characterization of Europe's rural landscapes. The characterization identifies hotspots of cultural landscapes, where all three dimensions are present, such as in the Mediterranean. On the other hand, Eastern and Northern...

  11. Landscape moderation of biodiversity patterns and processes - eight hypotheses.

    Science.gov (United States)

    Tscharntke, Teja; Tylianakis, Jason M; Rand, Tatyana A; Didham, Raphael K; Fahrig, Lenore; Batáry, Péter; Bengtsson, Janne; Clough, Yann; Crist, Thomas O; Dormann, Carsten F; Ewers, Robert M; Fründ, Jochen; Holt, Robert D; Holzschuh, Andrea; Klein, Alexandra M; Kleijn, David; Kremen, Claire; Landis, Doug A; Laurance, William; Lindenmayer, David; Scherber, Christoph; Sodhi, Navjot; Steffan-Dewenter, Ingolf; Thies, Carsten; van der Putten, Wim H; Westphal, Catrin

    2012-08-01

    Understanding how landscape characteristics affect biodiversity patterns and ecological processes at local and landscape scales is critical for mitigating effects of global environmental change. In this review, we use knowledge gained from human-modified landscapes to suggest eight hypotheses, which we hope will encourage more systematic research on the role of landscape composition and configuration in determining the structure of ecological communities, ecosystem functioning and services. We organize the eight hypotheses under four overarching themes. Section A: 'landscape moderation of biodiversity patterns' includes (1) the landscape species pool hypothesis-the size of the landscape-wide species pool moderates local (alpha) biodiversity, and (2) the dominance of beta diversity hypothesis-landscape-moderated dissimilarity of local communities determines landscape-wide biodiversity and overrides negative local effects of habitat fragmentation on biodiversity. Section B: 'landscape moderation of population dynamics' includes (3) the cross-habitat spillover hypothesis-landscape-moderated spillover of energy, resources and organisms across habitats, including between managed and natural ecosystems, influences landscape-wide community structure and associated processes and (4) the landscape-moderated concentration and dilution hypothesis-spatial and temporal changes in landscape composition can cause transient concentration or dilution of populations with functional consequences. Section C: 'landscape moderation of functional trait selection' includes (5) the landscape-moderated functional trait selection hypothesis-landscape moderation of species trait selection shapes the functional role and trajectory of community assembly, and (6) the landscape-moderated insurance hypothesis-landscape complexity provides spatial and temporal insurance, i.e. high resilience and stability of ecological processes in changing environments. Section D: 'landscape constraints on

  12. Decipher the mechanisms of protein conformational changes induced by nucleotide binding through free-energy landscape analysis: ATP binding to Hsp70.

    Directory of Open Access Journals (Sweden)

    Adrien Nicolaï

    Full Text Available ATP regulates the function of many proteins in the cell by transducing its binding and hydrolysis energies into protein conformational changes by mechanisms which are challenging to identify at the atomic scale. Based on molecular dynamics (MD simulations, a method is proposed to analyze the structural changes induced by ATP binding to a protein by computing the effective free-energy landscape (FEL of a subset of its coordinates along its amino-acid sequence. The method is applied to characterize the mechanism by which the binding of ATP to the nucleotide-binding domain (NBD of Hsp70 propagates a signal to its substrate-binding domain (SBD. Unbiased MD simulations were performed for Hsp70-DnaK chaperone in nucleotide-free, ADP-bound and ATP-bound states. The simulations revealed that the SBD does not interact with the NBD for DnaK in its nucleotide-free and ADP-bound states whereas the docking of the SBD was found in the ATP-bound state. The docked state induced by ATP binding found in MD is an intermediate state between the initial nucleotide-free and final ATP-bound states of Hsp70. The analysis of the FEL projected along the amino-acid sequence permitted to identify a subset of 27 protein internal coordinates corresponding to a network of 91 key residues involved in the conformational change induced by ATP binding. Among the 91 residues, 26 are identified for the first time, whereas the others were shown relevant for the allosteric communication of Hsp70 s in several experiments and bioinformatics analysis. The FEL analysis revealed also the origin of the ATP-induced structural modifications of the SBD recently measured by Electron Paramagnetic Resonance. The pathway between the nucleotide-free and the intermediate state of DnaK was extracted by applying principal component analysis to the subset of internal coordinates describing the transition. The methodology proposed is general and could be applied to analyze allosteric communication in

  13. A PM7 dynamic residue-ligand interactions energy landscape of the BACE1 inhibitory pathway by hydroxyethylamine compounds. Part I: The flap closure process.

    Science.gov (United States)

    Gueto-Tettay, Carlos; Martinez-Consuegra, Alejandro; Zuchniarz, Joshua; Gueto-Tettay, Luis Roberto; Drosos-Ramírez, Juan Carlos

    2017-09-01

    BACE1 is an enzyme of scientific interest because it participates in the progression of Alzheimer's disease. Hydroxyethylamines (HEAs) are a family of compounds which exhibit inhibitory activity toward BACE1 at a nanomolar level, favorable pharmacokinetic properties and oral bioavailability. The first step in the inhibition of BACE1 by HEAs consists of their entrance into the protease active site and the resultant conformational change in the protein, from Apo to closed form. These two conformations differ in the position of an antiparallel loop (called the flap) which covers the entrance to the catalytic site. For BACE1, closure of this flap is vital to its catalytic activity and to inhibition of the enzyme due to the new interactions thereby formed with the ligand. In the present study a dynamic energy landscape of residue-ligand interaction energies (ReLIE) measured for 112 amino acids in the BACE1 active site and its immediate vicinity during the closure of the flap induced by 8 HEAs of different inhibitory power is presented. A total of 6.272 million ReLIE calculations, based on the PM7 semiempirical method, provided a deep and quantitative view of the first step in the inhibition of the aspartyl protease. The information suggests that residues Asp93, Asp289, Thr292, Thr293, Asn294 and Arg296 are anchor points for the ligand, accounting for approximately 45% of the total protein-ligand interaction. Additionally, flap closure improved the BACE1-HEA interaction by around 25%. Furthermore, the inhibitory activity of HEAs could be related to the capacity of these ligands to form said anchor point interactions and maintain them over time: the lack of some of these anchor interactions delayed flap closure or impeded it completely, or even caused the flap to reopen. The methodology employed here could be used as a tool to evaluate future structural modifications which lead to improvements in the favorability and stability of BACE1-HEA ReLIEs, aiding in the design of

  14. Buildings Interoperability Landscape

    Energy Technology Data Exchange (ETDEWEB)

    Hardin, Dave [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stephan, Eric G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wang, Weimin [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Corbin, Charles D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Widergren, Steven E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-12-31

    Through its Building Technologies Office (BTO), the United States Department of Energy’s Office of Energy Efficiency and Renewable Energy (DOE-EERE) is sponsoring an effort to advance interoperability for the integration of intelligent buildings equipment and automation systems, understanding the importance of integration frameworks and product ecosystems to this cause. This is important to BTO’s mission to enhance energy efficiency and save energy for economic and environmental purposes. For connected buildings ecosystems of products and services from various manufacturers to flourish, the ICT aspects of the equipment need to integrate and operate simply and reliably. Within the concepts of interoperability lie the specification, development, and certification of equipment with standards-based interfaces that connect and work. Beyond this, a healthy community of stakeholders that contribute to and use interoperability work products must be developed. On May 1, 2014, the DOE convened a technical meeting to take stock of the current state of interoperability of connected equipment and systems in buildings. Several insights from that meeting helped facilitate a draft description of the landscape of interoperability for connected buildings, which focuses mainly on small and medium commercial buildings. This document revises the February 2015 landscape document to address reviewer comments, incorporate important insights from the Buildings Interoperability Vision technical meeting, and capture thoughts from that meeting about the topics to be addressed in a buildings interoperability vision. In particular, greater attention is paid to the state of information modeling in buildings and the great potential for near-term benefits in this area from progress and community alignment.

  15. Energy Landscapes of Folding Chromosomes

    Science.gov (United States)

    Zhang, Bin

    The genome, the blueprint of life, contains nearly all the information needed to build and maintain an entire organism. A comprehensive understanding of the genome is of paramount interest to human health and will advance progress in many areas, including life sciences, medicine, and biotechnology. The overarching goal of my research is to understand the structure-dynamics-function relationships of the human genome. In this talk, I will be presenting our efforts in moving towards that goal, with a particular emphasis on studying the three-dimensional organization, the structure of the genome with multi-scale approaches. Specifically, I will discuss the reconstruction of genome structures at both interphase and metaphase by making use of data from chromosome conformation capture experiments. Computationally modeling of chromatin fiber at atomistic level from first principles will also be presented as our effort for studying the genome structure from bottom up.

  16. Branches of the landscape

    International Nuclear Information System (INIS)

    Dine, Michael; O'Neil, Deva; Sun Zheng

    2005-01-01

    With respect to the question of supersymmetry breaking, there are three branches of the flux landscape. On one of these, if one requires small cosmological constant, supersymmetry breaking is predominantly at the fundamental scale; on another, the distribution is roughly flat on a logarithmic scale; on the third, the preponderance of vacua are at very low scale. A priori, as we will explain, one can say little about the first branch. The vast majority of these states are not accessible even to crude, approximate analysis. On the other two branches one can hope to do better. But as a result of the lack of access to branch one, and our poor understanding of cosmology, we can at best conjecture about whether string theory predicts low energy supersymmetry or not. If we hypothesize that are on branch two or three, distinctive predictions may be possible. We comment of the status of naturalness within the landscape, deriving, for example, the statistics of the first branch from simple effective field theory reasoning

  17. Lines of landscape organisation

    DEFF Research Database (Denmark)

    Løvschal, Mette

    2015-01-01

    This paper offers a landscape analysis of the earliest linear landscape boundaries on Skovbjerg Moraine, Denmark, during the first millennium BC. Using Delaunay triangulation as well as classic distribution analyses, it demonstrates that landscape boundaries articulated already established use-pa...

  18. Flowscapes : Infrastructure as landscape, landscape as infrastructure. Graduation Lab Landscape Architecture 2012/2013

    NARCIS (Netherlands)

    Nijhuis, S.; Jauslin, D.; De Vries, C.

    2012-01-01

    Flowscapes explores infrastructure as a type of landscape and landscape as a type of infrastructure, and is focused on landscape architectonic design of transportation-, green- and water infrastructures. These landscape infrastructures are considered armatures for urban and rural development. With

  19. How wind power landscapes change

    DEFF Research Database (Denmark)

    Möller, Bernd

    2006-01-01

    Following 25 years of continuous development, Danish wind energy landscapes are going to face changes. Ceased on-shore construction, unresolved re-powering and stalled regional planning characterize the situation overshadowed by off-shore development. One of the factors inhibiting development...... in general. However, the pattern of visibility will become askew, and the present homogenous distribution of visibility will disappear. This skewness, together with changing ownership and receding local involvement, could eventually lead to lower popular acceptance of wind power....

  20. Do geographically isolated wetlands influence landscape functions?

    OpenAIRE

    Cohen, Matthew J.; Creed, Irena F.; Alexander, Laurie; Basu, Nandita B.; Calhoun, Aram J. K.; Craft, Christopher; D’Amico, Ellen; DeKeyser, Edward; Fowler, Laurie; Golden, Heather E.; Jawitz, James W.; Kalla, Peter; Kirkman, L. Katherine; Lane, Charles R.; Lang, Megan

    2016-01-01

    Geographically isolated wetlands (GIWs), those surrounded by uplands, exchange materials, energy, and organisms with other elements in hydrological and habitat networks, contributing to landscape functions, such as flow generation, nutrient and sediment retention, and biodiversity support. GIWs constitute most of the wetlands in many North American landscapes, provide a disproportionately large fraction of wetland edges where many functions are enhanced, and form complexes with other water bo...

  1. Nonequilibrium landscape theory of neural networks.

    Science.gov (United States)

    Yan, Han; Zhao, Lei; Hu, Liang; Wang, Xidi; Wang, Erkang; Wang, Jin

    2013-11-05

    The brain map project aims to map out the neuron connections of the human brain. Even with all of the wirings mapped out, the global and physical understandings of the function and behavior are still challenging. Hopfield quantified the learning and memory process of symmetrically connected neural networks globally through equilibrium energy. The energy basins of attractions represent memories, and the memory retrieval dynamics is determined by the energy gradient. However, the realistic neural networks are asymmetrically connected, and oscillations cannot emerge from symmetric neural networks. Here, we developed a nonequilibrium landscape-flux theory for realistic asymmetrically connected neural networks. We uncovered the underlying potential landscape and the associated Lyapunov function for quantifying the global stability and function. We found the dynamics and oscillations in human brains responsible for cognitive processes and physiological rhythm regulations are determined not only by the landscape gradient but also by the flux. We found that the flux is closely related to the degrees of the asymmetric connections in neural networks and is the origin of the neural oscillations. The neural oscillation landscape shows a closed-ring attractor topology. The landscape gradient attracts the network down to the ring. The flux is responsible for coherent oscillations on the ring. We suggest the flux may provide the driving force for associations among memories. We applied our theory to rapid-eye movement sleep cycle. We identified the key regulation factors for function through global sensitivity analysis of landscape topography against wirings, which are in good agreements with experiments.

  2. Why Landscape Beauty Matters

    Directory of Open Access Journals (Sweden)

    Angelika Krebs

    2014-11-01

    Full Text Available This philosophical paper explores the aesthetic argument for landscape conservation. The main claim is that the experience of beautiful landscapes is an essential part of the good human life. Beautiful landscapes make us feel at home in the world. Their great and irreplaceable value lies therein. To establish this claim, the concepts of landscape and “Stimmung” are clarified. It is shown how “Stimmung” (in the sense of mood is infused into landscape (as atmosphere and how we respond to it aesthetically. We respond by resonating or feeling at home. The paper ends by indicating how art can help us to better appreciate landscape beauty. This is done by way of an example from contemporary nature poetry, Michael Donhauser’s Variationen in Prosa, which begins with “Und was da war, es nahm uns an” (“And what was there accepted us”.

  3. Energy Saver: Tips on Saving Money & Energy at Home

    Energy Technology Data Exchange (ETDEWEB)

    None

    2017-09-01

    Provides consumers with home energy and money savings tips such as insulation, weatherization, heating, cooling, water heating, energy efficient windows, landscaping, lighting, and energy efficient appliances.

  4. Energy Savers Tips on Saving Energy& Money at Home

    Energy Technology Data Exchange (ETDEWEB)

    2003-06-01

    Provides consumers with home energy and money savings tips such as insulation, weatherization, heating, cooling, water heating, energy efficient windows, landscaping, lighting, and energy efficient appliances

  5. Energy Savers: Tips on Saving Money & Energy at Home

    Energy Technology Data Exchange (ETDEWEB)

    None

    2011-12-01

    Provides consumers with home energy and money savings tips such as insulation, weatherization, heating, cooling, water heating, energy efficient windows, landscaping, lighting, and energy efficient appliances.

  6. Energy Savers: Tips on Saving Money & Energy at Home

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-05-01

    Provides consumers with home energy and money savings tips such as insulation, weatherization, heating, cooling, water heating, energy efficient windows, landscaping, lighting, and energy efficient appliances.

  7. Do geographically isolated wetlands influence landscape functions?

    Science.gov (United States)

    Cohen, Matthew J.; Creed, Irena F.; Alexander, Laurie C.; Basu, Nandita; Calhoun, Aram J.K.; Craft, Christopher; D’Amico, Ellen; DeKeyser, Edward S.; Fowler, Laurie; Golden, Heather E.; Jawitz, James W.; Kalla, Peter; Kirkman, L. Katherine; Lane, Charles R.; Lang, Megan; Leibowitz, Scott G.; Lewis, David Bruce; Marton, John; McLaughlin, Daniel L.; Mushet, David M.; Raanan-Kiperwas, Hadas; Rains, Mark C.; Smith, Lora; Walls, Susan C.

    2015-01-01

    Geographically isolated wetlands (GIWs), those surrounded by uplands, exchange materials, energy, and organisms with other elements in hydrological and habitat networks, contributing to landscape functions, such as flow generation, nutrient and sediment retention, and biodiversity support. GIWs constitute most of the wetlands in many North American landscapes, provide a disproportionately large fraction of wetland edges where many functions are enhanced, and form complexes with other water bodies to create spatial and temporal heterogeneity in the timing, flow paths, and magnitude of network connectivity. These attributes signal a critical role for GIWs in sustaining a portfolio of landscape functions, but legal protections remain weak despite preferential loss from many landscapes. GIWs lack persistent surface water connections, but this condition does not imply the absence of hydrological, biogeochemical, and biological exchanges with nearby and downstream waters. Although hydrological and biogeochemical connectivity is often episodic or slow (e.g., via groundwater), hydrologic continuity and limited evaporative solute enrichment suggest both flow generation and solute and sediment retention. Similarly, whereas biological connectivity usually requires overland dispersal, numerous organisms, including many rare or threatened species, use both GIWs and downstream waters at different times or life stages, suggesting that GIWs are critical elements of landscape habitat mosaics. Indeed, weaker hydrologic connectivity with downstream waters and constrained biological connectivity with other landscape elements are precisely what enhances some GIW functions and enables others. Based on analysis of wetland geography and synthesis of wetland functions, we argue that sustaining landscape functions requires conserving the entire continuum of wetland connectivity, including GIWs.

  8. Landscape equivalent of the shoving model

    DEFF Research Database (Denmark)

    Dyre, Jeppe; Olsen, Niels Boye

    2004-01-01

    It is shown that the shoving model expression for the average relaxation time of viscous liquids, according to which the activation energy is proportional to the instantaneous shear modulus, follows largely from a classical "landscape" estimation of barrier heights from curvature at energy minima...

  9. Condensed landscape experience

    DEFF Research Database (Denmark)

    Earon, Ofri

    2011-01-01

    ‘Re-thinking interaction between landscape and urban buildings’ participates in an interdisciplinary discourse about the theoretical and practical advantages of openly juxtaposing landscape and architecture without having one more advanced in importance. Recently, the greenification of buildings...... demands, quality of space, mixture of functions, urban complexity, public life and cultural heritage. In order to launch such an approach, an understanding of the spatial, social and environmental significance of a radical re-thinking of relationships between architecture and landscape is necessary...

  10. The shifting beverage landscape.

    Science.gov (United States)

    Storey, Maureen

    2010-04-26

    STOREY, M.L. The shifting beverage landscape. PHYSIOL BEHAV, 2010. - Simultaneous lifestyle changes have occurred in the last few decades, creating an imbalance in energy intake and energy expenditure that has led to overweight and obesity. Trends in the food supply show that total daily calories available per capita increased 28% since 1970. Total energy intake among men and women has also increased dramatically since that time. Some have suggested that intake of beverages has had a disproportional impact on obesity. Data collected by the Beverage Marketing Corporation between 1988-2008 demonstrate that, in reality, fewer calories per ounce are being produced by the beverage industry. Moreover, data from the National Cancer Institute show that soft drink intake represents 5.5% of daily calories. Data from NHANES 1999-2003 vs. 2003-06 may demonstrate a shift in beverage consumption for age/gender groups, ages 6 to>60years. The beverages provided in schools have significantly changed since 2006 when the beverage industry implemented School Beverage Guidelines. This voluntary action has removed full-calorie soft drinks from participating schools across the country. This shift to lower-calorie and smaller-portion beverages in school has led to a significant decrease in total beverage calories in schools. These data support the concept that to prevent and treat obesity, public health efforts should focus on energy balance and that a narrow focus on sweetened beverages is unlikely to have any meaningful impact on this complex problem. Copyright 2010 Elsevier Inc. All rights reserved.

  11. Our Common Landscapes For The Future

    DEFF Research Database (Denmark)

    Brandt, Jesper

    2017-01-01

    Foreword for Marc Antrop and Veerle van Eetvelde: Landscape Perspectives – The Holistic Nature of Landscapes Our common landscapes for the future by Jesper Brandt The solution of the ecological crisis through a transformation towards sustainable development is the most urgent challenge in our time....... It is not just a question of CO2 and conversion toward renewable energy. The reestablishment and conscious development of our common landscapes at all spatial scales for the combined benefits of biodiversity, our cultural heritage and the preservation and development of ecosystem services will probably...... be the most comprehensive and necessary social task in the future, if a conversion towards a sustainable development shall succeed in due time. This is so because it will be necessary to ensure that the potential material wealth of modern society will be transformed into a good, fruitful and healthy life...

  12. Inland drift sand landscapes

    NARCIS (Netherlands)

    Fanta, J.; Siepel, H.

    2010-01-01

    Man has had a complex relationship with inland drift sands through the ages. For some centuries these landscapes were seen as a threat to society, especially agriculture and housing. At present we conserve these landscapes as important Natura 2000 priority habitats. In this book you may find these

  13. Principles of landscape architecture

    NARCIS (Netherlands)

    Nijhuis, S.

    2013-01-01

    The Department of Urbanism at the Faculty of Architecture and Built Environment, TU Delft considers urbanism as a planning and design oriented activity towards urban and rural landscapes. It aims to enhance, restore or create landscapes from a perspective of sustainable development, so as to guide,

  14. Nature and landscape protection

    International Nuclear Information System (INIS)

    Klinda, J.; Lieskovska, Z.

    1998-01-01

    In accordance with National Council of the Slovak Republic Act N. 287/1994 Coll. on Nature and Landscape Protection, the system of complex nature landscape protection has been designed based on five levels of protection. Categories of protected areas as well as cultural monuments in the Slovak Republic are reviewed.Slovak contribution to the world heritage is included

  15. Globalization and Landscape Architecture

    OpenAIRE

    Robert R. Hewitt

    2014-01-01

    The literature review examines globalization and landscape architecture as discourse, samples its various meanings, and proposes methods to identify and contextualize its specific literature. Methodologically, the review surveys published articles and books by leading authors and within the WorldCat.org Database associated with landscape architecture and globalization, analyzing survey results for comprehensive concept...

  16. Glossary on agricultural landscapes.

    NARCIS (Netherlands)

    Kruse, A.; Centeri, C.; Renes, J.; Roth, M.; Printsman, A.; Palang, H.; Benito Jorda, M.-D.; Verlarde, M.D.; Kruckenberg, H.

    2010-01-01

    T he following glossary of terms related to the European agricultural landscape shall serve as a common basis for all parties, working in or on agricultural landscapes. Some of the terms are quite common and sometimes used in our every day language, but they often have different meanings in

  17. Urban Landscape Perspectives

    Directory of Open Access Journals (Sweden)

    Frederick Steiner

    2014-03-01

    Full Text Available Cities present significant opportunities for new landscape perspectives that can help inform conservation and development decisions. Early in the twenty-first century, the majority of the planet’s population became urban as more people lived in city-regions for the first time in our history. As the global population increases, so does this urbanization. The environmental challenges of population and urban growth are profound. Landscapes represent a synthesis of natural and cultural processes. Cities are certainly cultural phenomena. Historically, cities provided refuge from nature. The expanding field of urban ecology, coupled with landscape ecology, can enhance how the dual natural and cultural dimensions of landscapes in cities are understood. Furthermore, concepts such as ecosystem services and green infrastructure are proving useful for urban landscape planning and design. Examples from Dayton, Ohio; Brooklyn, New York; and Austin, Texas are presented.

  18. Nonequilibrium landscape theory of neural networks

    Science.gov (United States)

    Yan, Han; Zhao, Lei; Hu, Liang; Wang, Xidi; Wang, Erkang; Wang, Jin

    2013-01-01

    The brain map project aims to map out the neuron connections of the human brain. Even with all of the wirings mapped out, the global and physical understandings of the function and behavior are still challenging. Hopfield quantified the learning and memory process of symmetrically connected neural networks globally through equilibrium energy. The energy basins of attractions represent memories, and the memory retrieval dynamics is determined by the energy gradient. However, the realistic neural networks are asymmetrically connected, and oscillations cannot emerge from symmetric neural networks. Here, we developed a nonequilibrium landscape–flux theory for realistic asymmetrically connected neural networks. We uncovered the underlying potential landscape and the associated Lyapunov function for quantifying the global stability and function. We found the dynamics and oscillations in human brains responsible for cognitive processes and physiological rhythm regulations are determined not only by the landscape gradient but also by the flux. We found that the flux is closely related to the degrees of the asymmetric connections in neural networks and is the origin of the neural oscillations. The neural oscillation landscape shows a closed-ring attractor topology. The landscape gradient attracts the network down to the ring. The flux is responsible for coherent oscillations on the ring. We suggest the flux may provide the driving force for associations among memories. We applied our theory to rapid-eye movement sleep cycle. We identified the key regulation factors for function through global sensitivity analysis of landscape topography against wirings, which are in good agreements with experiments. PMID:24145451

  19. Planetary Landscape Geography

    Science.gov (United States)

    Hargitai, H.

    INTRODUCTION Landscape is one of the most often used category in physical ge- ography. The term "landshap" was introduced by Dutch painters in the 15-16th cen- tury. [1] The elements that build up a landscape (or environment) on Earth consists of natural (biogenic and abiogenic - lithologic, atmospheric, hydrologic) and artificial (antropogenic) factors. Landscape is a complex system of these different elements. The same lithology makes different landscapes under different climatic conditions. If the same conditions are present, the same landscape type will appear. Landscapes build up a hierarchic system and cover the whole surface. On Earth, landscapes can be classified and qualified according to their characteristics: relief forms (morphology), and its potential economic value. Aesthetic and subjective parameters can also be considered. Using the data from landers and data from orbiters we can now classify planetary landscapes (these can be used as geologic mapping units as well). By looking at a unknown landscape, we can determine the processes that created it and its development history. This was the case in the Pathfinder/Sojourner panoramas. [2]. DISCUSSION Planetary landscape evolution. We can draw a raw landscape develop- ment history by adding the different landscape building elements to each other. This has a strong connection with the planet's thermal evolution (age of the planet or the present surface materials) and with orbital parameters (distance from the central star, orbit excentricity etc). This way we can build a complex system in which we use differ- ent evolutional stages of lithologic, atmospheric, hydrologic and biogenic conditions which determine the given - Solar System or exoplanetary - landscape. Landscape elements. "Simple" landscapes can be found on asteroids: no linear horizon is present (not differentiated body, only impact structures), no atmosphere (therefore no atmospheric scattering - black sky as part of the landscape) and no

  20. Impacts of energy crop cultivation on nature and landscape. Development and application of an evaluation method; Auswirkungen des Energiepflanzenanbaus auf Natur und Landschaft. Entwicklung und Anwendung einer Bewertungsmethode

    Energy Technology Data Exchange (ETDEWEB)

    Wiehe, Julia

    2011-08-15

    For long-term planning, knowledge about the interrelationship of effects of the cultivation method and the sensitivity of ecological balance is essential. Hence, the objective of this thesis is the development of a method for the evaluation of the impacts of bioenergy crop production for biogas use on the natural environment. The developed method is in alignment with existing methods. It is also in alignment with those methods used within the practice of landscape planning, so that the method as well as the derived conclusions can be implemented into landscape planning practice in the future. The evaluation method has been applied in the three model regions Hildesheim, Soltau-Fallingbostel and Emsland. These test areas represent different physical regions in Lower Saxony and typical agricultural production conditions. On the basis of these results, general statements on the impact of bioenergy crop production on the ecological balance of the area can be made. [German] Grundlage fuer eine vorausschauende Steuerung des Ausbaus erneuerbarer Energien ist die Kenntnis der Zusammenhaenge der Wirkung des Energiepflanzenanbaus und der Empfindlichkeit des Naturhaushaltes. Ziel der Arbeit ist daher die Erarbeitung einer Methode zur umfassenden Bewertung dieser Auswirkungen auf den Naturhaushalt. Die Methode orientiert sich an bereits bestehenden und in der Praxis der Landschaftsplanung angewendeten Bewertungsmethoden, so dass sie ebenso wie die daraus abgeleiteten Schlussfolgerungen zukuenftig Eingang in die Planungspraxis finden kann. Die Bewertungsmethode wird in den drei Modellregionen Hildesheim, Soltau-Fallingbostel und Emsland angewendet, mit denen die verschiedenen Naturraeume und fuer Niedersachsen typischen landwirtschaftlichen Produktionsbedingungen abgebildet werden. Auf Grundlage dieser Ergebnisse koennen dann allgemeine Aussagen zu den Auswirkungen des Energiepflanzenanbaus auf den Naturhaushalt gemacht werden.

  1. Welfare Landscape and Communities

    DEFF Research Database (Denmark)

    Braae, Ellen Marie

    2017-01-01

    Danish housing developments of the post-war era were a cornerstone in the implementation of the welfare vision and the overall urban and landscape planning in the post-war period. The new city was a horizontal city and – as it will be my primary ambition to show – a green and landscape-like city....... The landscape came, in Denmark, to play a prominent role and became synonymous with ‘The Good Life’, but it also presented a number of moral imperatives. The article concerns how communities and community feelings found their expression in the Danish ‘welfare landscapes’....

  2. Weathering and landscape evolution

    Science.gov (United States)

    Turkington, Alice V.; Phillips, Jonathan D.; Campbell, Sean W.

    2005-04-01

    In recognition of the fundamental control exerted by weathering on landscape evolution and topographic development, the 35th Binghamton Geomorphology Symposium was convened under the theme of Weathering and Landscape Evolution. The papers and posters presented at the conference imparted the state-of-the-art in weathering geomorphology, tackled the issue of scale linkage in geomorphic studies and offered a vehicle for interdisciplinary communication on research into weathering and landscape evolution. The papers included in this special issue are encapsulated here under the general themes of weathering mantles, weathering and relative dating, weathering and denudation, weathering processes and controls and the 'big picture'.

  3. Quality criteria for landscape visualisation

    International Nuclear Information System (INIS)

    Waldi, H.-P.; Witt, U. de

    1996-01-01

    The rapid expansion of wind energy utilisation in Western Europe can strain the limits of social acceptance with citizens living in wind development areas. One of the problems wind farm engineers and local authorities face is the visual impact of wind turbines. To determine the influence on the landscape visualisations of wind farms photorealistic compositions are used. In many cases it is part of the planning procedure. The quality of this visualization can strongly influence the success of the permission procedure. We will give criteria which can give help to reduce the possibility of unwanted manipulations. (author)

  4. Landscape metrics application in ecological and visual landscape assessment

    Directory of Open Access Journals (Sweden)

    Gavrilović Suzana

    2017-01-01

    Full Text Available The development of landscape-ecological approach application in spatial planning provides exact theoretical and empirical evidence for monitoring ecological consequences of natural and/or anthropogenic factors, particularly changes in spatial structures caused by them. Landscape pattern which feature diverse landscape values is the holder of the unique landscape character at different spatial levels and represents a perceptual domain for its users. Using the landscape metrics, the parameters of landscape composition and configuration are mathematical algorithms that quantify the specific spatial characteristics used for interpretation of landscape features and processes (physical and ecological aspect, as well as forms (visual aspect and the meaning (cognitive aspect of the landscape. Landscape metrics has been applied mostly in the ecological and biodiversity assessments as well as in the determination of the level of structural change of landscape, but more and more applied in the assessment of the visual character of the landscape. Based on a review of relevant literature, the aim of this work is to show the main trends of landscape metrics within the aspect of ecological and visual assessments. The research methodology is based on the analysis, classification and systematization of the research studies published from 2000 to 2016, where the landscape metrics is applied: (1 the analysis of landscape pattern and its changes, (2 the analysis of biodiversity and habitat function and (3 a visual landscape assessment. By selecting representative metric parameters for the landscape composition and configuration, for each category is formed the basis for further landscape metrics research and application for the integrated ecological and visual assessment of the landscape values. Contemporary conceptualization of the landscape is seen holistically, and the future research should be directed towards the development of integrated landscape assessment

  5. Landscape genetics and limiting factors

    Science.gov (United States)

    Samuel A. Cushman; Andrew J. Shirk; Erin L. Landguth

    2013-01-01

    Population connectivity is mediated by the movement of organisms or propagules through landscapes. However, little is known about how variation in the pattern of landscape mosaics affects the detectability of landscape genetic relationships. The goal of this paper is to explore the impacts of limiting factors on landscape genetic processes using simulation...

  6. Condensed landscape experience

    DEFF Research Database (Denmark)

    Earon, Ofri

    2011-01-01

    demands, quality of space, mixture of functions, urban complexity, public life and cultural heritage. In order to launch such an approach, an understanding of the spatial, social and environmental significance of a radical re-thinking of relationships between architecture and landscape is necessary...... is becoming a standard in contemporary architecture. Merging architecture and landscape has turned into a principle for an ecological / sustainable architecture. Yet, my aspiration is to achieve a wider interaction involving an application of a wider range of perspectives, such as: urban identity, social......‘Re-thinking interaction between landscape and urban buildings’ participates in an interdisciplinary discourse about the theoretical and practical advantages of openly juxtaposing landscape and architecture without having one more advanced in importance. Recently, the greenification of buildings...

  7. PNW Hydrologic Landscape Class

    Data.gov (United States)

    U.S. Environmental Protection Agency — Work has been done to expand the hydrologic landscapes (HLs) concept and to develop an approach for using it to address streamflow vulnerability from climate change....

  8. Appropriate complexity landscape modeling

    NARCIS (Netherlands)

    Larsen, Laurel G.; Eppinga, Maarten B.; Passalacqua, Paola; Getz, Wayne M.; Rose, Kenneth A.; Liang, Man

    Advances in computing technology, new and ongoing restoration initiatives, concerns about climate change's effects, and the increasing interdisciplinarity of research have encouraged the development of landscape-scale mechanistic models of coupled ecological-geophysical systems. However,

  9. Digital landscapes of imagination

    OpenAIRE

    Starlight Vattano

    2014-01-01

    Urban landscapes that exist in the expression of an imaginative sequence define their shape through the digital representation. These hyperreal dimensions, combine imagination and representation as constituents a new reality, which follows the utopian, suprematist and constructivist theories, where the two-dimensional dynamics is transformed into an infinite space in which the imagination creates new forms. Although interpretations of the urban landscape film, put in place a correspondence be...

  10. Biomass yield from an urban landscape

    Science.gov (United States)

    Utilizing biomass from urban landscapes could significantly contribute to the nation’s renewable energy needs. In 2007, an experiment was begun to evaluate the biomass production from a bermudagrass, Cynodon dactylon var. dactylon (L.) Pers., lawn in Woodward, Oklahoma and to estimate the potential...

  11. New infrastructures, new landscapes

    Directory of Open Access Journals (Sweden)

    Chiara Nifosì

    2014-06-01

    Full Text Available New infrastructures, new landscapes AbstractThe paper will discuss one recent Italian project that share a common background: the relevance of the existing maritime landscape as a non negotiable value. The studies will be discussed in details a feasibility study for the new port in Monfalcone. National infrastructural policies emphasize competitiveness and connection as a central issue incultural, economic and political development of communities . Based on networks and system development along passageways that make up the European infrastructural armor; the two are considered at the meantime as cause and effect of "territorialisation”. These two views are obviously mutually dependent. It's hard to think about a strong attractiveness out of the network, and to be part of the latter encourages competitiveness. Nonetheless this has proved to be conflictual when landscape values and the related attractiveness are considered.The presented case study project, is pursuing the ambition to promote a new approach in realizing large infrastructures; its double role is to improve connectivity and to generate lasting and positive impact on the local regions. It deal with issues of inter-modality and the construction of nodes and lines which connects Europe, and its markets.Reverting the usual approach which consider landscape project as as a way to mitigate or to compensate for the infrastructure, the goal is to succeed in realizing large infrastructural works by conceiving them as an occasion to reinterpret a region or, as extraordinary opportunities, to build new landscapes.The strategy proposed consists in achieving structural images based on the reinforcement of the environmental and historical-landscape systems. Starting from the reinterpretation of local maritime context and resources it is possible not just to preserve the attractiveness of a specific landscape but also to conceive infrastructure in a more efficient way. 

  12. Semiotics in landscape design

    Directory of Open Access Journals (Sweden)

    Karsten Jorgensen

    1997-03-01

    Full Text Available This paper claims that concepts of language can help us create better and more relevant landscape design. It is based on research undertaken by Karsten Jørgensen (1989, and subsequent studies carried out at the department of Land Use and Landscape Planning at the Agricultural University in Norway. The 'signs' that constitute the design language are categorised using the analytical vocabulary of landscape design; for example, elements, materials, effects and shapes. Studies of these signs are based on elements of semiotics and cognitive science, especially the Umwelt-theories developed by Jakob von Uexküll (Hoffmeyer 1994. We are constantly exposed to numerous signs of different kinds. Everywhere in society we see signs around us; for example, traffic signs, advertising signs and logos. It is therefore relevant to introduce the term 'semiosphere' in order to focus on the significance of semiosis at all levels of activity in the world, from cellular activities, to complex systems of development such as those found in a population. This study focuses on the semantic aspects of landscape architecture. In explaining the meaning of a statement, it is useful to have a set of rules or 'codes' to correlate a specific expression with a specific interpretation. These codes may be based on conventions, or on similarity between or stylisation of objects, such as natural or cultural landscapes. In any case, they are based on the interpreter's language and 'mind-structure'. At a general level, it is only possible to study sign content. To analyse meaning in landscape design you have to look at the context; for example, the overall composition of a garden or park and the situation, which includes the interpreter's cultural background, their experiences and so on. In other words, you have to analyse a specific case to be able to speak reasonably about meaning in landscape (designs.

  13. European landscape architecture and territorial strategies for water landscapes

    DEFF Research Database (Denmark)

    Diedrich, Lisa Babette

    2010-01-01

    This article sums up the author’s lecture at the 2009 Sydney Resilient Water Landscapes Symposium and presents a series of realized or planned European landscape architectural and urbanistic projects on water landscapes taken from the recently published book On Site/ Landscape Architecture Europe...... and accompanying reflections. The hypothesis is that further scientific research can help defining weaknesses and strengths of the existing water landscape designs in terms of resilience, extract principles and tools, improve the weak ones and communicate the strong ones and develop general quality criteria...... and tools for future resilient water landscapes....

  14. Geomorpho-Landscapes

    Science.gov (United States)

    Farabollini, Piero; Lugeri, Francesca; Amadio, Vittorio

    2014-05-01

    Landscape is the object of human perceptions, being the image of spatial organization of elements and structures: mankind lives the first approach with the environment, viewing and feeling the landscape. Many definitions of landscape have been given over time: in this case we refer to the Landscape defined as the result of interaction among physical, biotic and anthropic phenomena acting in a different spatial-temporal scale (Foreman & Godron) Following an Aristotelic approach in studying nature, we can assert that " Shape is synthesis": so it is possible to read the land features as the expression of the endogenous and exogenous processes that mould earth surfaces; moreover, Landscape is the result of the interaction of natural and cultural components, and conditions the spatial-temporal development of a region. The study of the Landscape offers results useful in order to promote sustainable development, ecotourism, enhancement of natural and cultural heritage, popularization of the scientific knowledge. In Italy, a very important GIS-based tool to represent the territory is the "Carta della Natura" ("Map of Nature", presently coordinated by the ISPRA) that aims at assessing the state of the whole Italian territory, analyzing Landscape. The methodology follows a holistic approach, taking into consideration all the components of a landscape and then integrating the information. Each individual landscape, studied at different scales, shows distinctive elements: structural, which depend on physical form and specific spatial organization; functional, which depend on relationships created between biotic and abiotic elements, and dynamic, which depend on the successive evolution of the structure. The identification of the landscape units, recognized at different scales of analysis, allows an evaluation of the state of the land, referring to the dual risk/resource which characterizes the Italian country. An interesting opportunity is to discover those areas of unusual

  15. Smart Landscape. The architecture of the "micro smart grid" as a resilience strategy for landscape

    OpenAIRE

    Garbarini, Giulia

    2018-01-01

    “Smart Landscape”, starting from energy devices for the management and distribution of electricity resources, tends to define a possible vision of landscape. The main structure and process are based on the architecture of a “micro smart grid”, which is generally associated with urban energy grids and districts, but may become a figurative reference for new forms of landscape, such as “Smart Landscape”. The output of the research would be to show how the main strategies of “Smart Landsc...

  16. Globalization and Landscape Architecture

    Directory of Open Access Journals (Sweden)

    Robert R. Hewitt

    2014-02-01

    Full Text Available The literature review examines globalization and landscape architecture as discourse, samples its various meanings, and proposes methods to identify and contextualize its specific literature. Methodologically, the review surveys published articles and books by leading authors and within the WorldCat.org Database associated with landscape architecture and globalization, analyzing survey results for comprehensive conceptual and co-relational frameworks. Three “higher order” dimensions frame the review’s conceptual organization, facilitating the organization of subordinate/subtopical areas of interest useful for comparative analysis. Comparative analysis of the literature suggests an uneven clustering of discipline-related subject matter across the literature’s “higher order” dimensions, with a much smaller body of literature related to landscape architecture confined primarily to topics associated with the dispersion of global phenomena. A subcomponent of this smaller body of literature is associated with other fields of study, but inferentially related to landscape architecture. The review offers separate references and bibliographies for globalization literature in general and globalization and landscape architecture literature, specifically.

  17. 邯郸市夜景观节能技术研究%Research on Handan city night-landscape energy conservation technology

    Institute of Scientific and Technical Information of China (English)

    胡金良; 齐海红

    2011-01-01

    通过对现代电气技术的研究,以可持续发展为理念,采用智能的控制系统、高效的灯具系统和绿色的能源系统,达到控制邯郸市夜景观能耗的目的,建成节能环保的夜景照明系统。%Pass the research to modern electric technology,take sustainable development as idea,adopt the intelligence navar,the high-effect lamp system and the sources of energy of green system,achieve the energy consumption controlling Handan city night-landscape' s purpose,establish the energy conservation environmental protection night scene illuminator.

  18. Potential energy landscape of an interstitial O2 molecule in a SiO2 film near the SiO2/Si(001) interface

    Science.gov (United States)

    Ohta, Hiromichi; Watanabe, Takanobu; Ohdomari, Iwao

    2008-10-01

    Potential energy distribution of interstitial O2 molecule in the vicinity of SiO2/Si(001) interface is investigated by means of classical molecular simulation. A 4-nm-thick SiO2 film model is built by oxidizing a Si(001) substrate, and the potential energy of an O2 molecule is calculated at Cartesian grid points with an interval of 0.05 nm in the SiO2 film region. The result shows that the potential energy of the interstitial site gradually rises with approaching the interface. The potential gradient is localized in the region within about 1 nm from the interface, which coincides with the experimental thickness of the interfacial strained layer. The potential energy is increased by about 0.62 eV at the SiO2/Si interface. The result agrees with a recently proposed kinetic model for dry oxidation of silicon [Phys. Rev. Lett. 96, 196102 (2006)], which argues that the oxidation rate is fully limited by the oxidant diffusion.

  19. Qualifying Urban Landscapes

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel; Nielsen, Tom; Daugaard, Morten

    2010-01-01

    The article presents an attempt to develop alternatives to the dominant planning and design principles used in building and rebuilding the contemporary urban landscape. The basic idea is that the ‘forces of modernisation’ driving current development might result in a broader and more interesting...... for contemporary urban landscape design practice....... to the task of constructing and improving things. With this goal, a set of objectives based in important insights from recent urban theory are formulated constituting the normative spine of the analysis of a number of found situations as basis for formulating eight generic concepts of qualification...

  20. Digital landscapes of imagination

    Directory of Open Access Journals (Sweden)

    Starlight Vattano

    2014-05-01

    Full Text Available Urban landscapes that exist in the expression of an imaginative sequence define their shape through the digital representation. These hyperreal dimensions, combine imagination and representation as constituents a new reality, which follows the utopian, suprematist and constructivist theories, where the two-dimensional dynamics is transformed into an infinite space in which the imagination creates new forms. Although interpretations of the urban landscape film, put in place a correspondence between reality and virtuality, into the modeling of spatial movements, from which do not arise contraries, but only interdependencies. It is a particular type of representation that takes shape via the digital in motion and provides new tools for urban representation.

  1. Imagine A Collective Landscape

    Directory of Open Access Journals (Sweden)

    Manuela Silvia Campanini

    2010-03-01

    Full Text Available Iceland plays a key role in the circumpolar context. The research investigates the fields of both the icelandic cultural landscape perception and the icelandic cultural identity. It considers the book Ultima thule; or, a summer in Iceland and Ólafur Elíasson art works as two sides of a same medal: the Iceland on the brain concept (F. Burton. The transition from a cultural identity to a collective landscape identity is investigated analysing Imagine J. Lennon's song which inspired Yõko Ono's work art titled Imagine Peace Tower.

  2. Selecting Landscape Plants: Shade Trees

    OpenAIRE

    Relf, Diane; Appleton, Bonnie Lee, 1948-2012; Close, David

    2015-01-01

    Because of the permanency of trees and their importance in the landscape, care must be taken to select the best species for each situation. This publication goes over how to choose landscape trees that are shade tolerant.

  3. Energy Savers--Tips on Saving Energy and Money at Home (Fifth Printing)

    International Nuclear Information System (INIS)

    DOE Office of Building Technology, State and Community Programs

    2001-01-01

    Provides consumers with home energy and money savings tips such as insulation, weatherization, heating, cooling, water heating, energy efficient windows, landscaping, lighting, and energy efficient appliances

  4. Energy Savers---Tips on Saving Energy and Money at Home (Fifth Printing)

    Energy Technology Data Exchange (ETDEWEB)

    DOE Office of Building Technology, State and Community Programs

    2001-08-13

    Provides consumers with home energy and money savings tips such as insulation, weatherization, heating, cooling, water heating, energy efficient windows, landscaping, lighting, and energy efficient appliances.

  5. Qualifying Urban Landscapes

    DEFF Research Database (Denmark)

    Juel Clemmensen, Thomas; Daugaard, Morten; Nielsen, Tom

    This paper is based on a research project aimed at contributing to the qualification of the aesthetical value of the contemporary urban landscape. We see our work as part of a tradition within the architectural profession of making explorative projects, which combines analysis of the contemporary...

  6. A landscape analysis plan

    Science.gov (United States)

    Nancy E. Fleenor

    2002-01-01

    A Landscape Analysis Plan (LAP) sets out broad guidelines for project development within boundaries of the Kings River Sustainable Forest Ecosystems Project. The plan must be a dynamic, living document, subject to change as new information arises over the course of this very long-term project (several decades). Two watersheds, each of 32,000 acres, were dedicated to...

  7. Ecology, recreation and landscape

    Energy Technology Data Exchange (ETDEWEB)

    Satchell, J E

    1983-01-01

    The article is dedicated to the problems of combining mass tourism in certain countries of Western Europe and environmental protection (OOS) requirements. The ecological damage from recreation is examined and the throughput of the medium is evaluated. The author proposes development of regulable, managable and controllable recreation use of natural resources and landscapes using selective advertising of the recreation sites.

  8. Landscape Planning of Schoolyards

    Science.gov (United States)

    Kopeva, A.; Khrapko, O.; Ivanova, O.

    2017-11-01

    The optimal landscape architecture planning of schoolyards allows for creation of favorable conditions for children personal development and physical fitness. The key principles of schoolyard landscape planning, same as for other areas intended for children, are as follows: establishment of a favorable microclimate, safety, aesthetic and educational environment. Green spaces play an essential role in this respect as they are essential to sanitary, hygienic, structural, and spatial planning performing decorative, artistic, cognitive, and educational functions in these areas. Various types of landscape plantings are used in school areas: borders, lawns, beds, vines, ornamental arrangements, and various potted plants. Children’s safety is the key principle when selecting a landscape design type and the plants’ range. Any allergenic, poisonous, thorny, strong-smelling or life-threatening plants are excluded. Plants on school grounds can serve as visual aids for studies. Drought-resistant, attractive, colorful, abundantly blooming plants with variable leaf texture are preferred. Ornamental trees and shrubs as well as perennials and annuals provide a broad plant range for school grounds.

  9. Landscape Assessment (LA)

    Science.gov (United States)

    Carl H. Key; Nathan C. Benson

    2006-01-01

    Landscape Assessment primarily addresses the need to identify and quantify fire effects over large areas, at times involving many burns. In contrast to individual case studies, the ability to compare results is emphasized along with the capacity to aggregate information across broad regions and over time. Results show the spatial heterogeneity of burns and how fire...

  10. Landscapes in transition

    NARCIS (Netherlands)

    Padfield, Rory; Drew, Simon; Syayuti, Khadijah; Page, Susan; Evers, Stephanie; Campos-Arceiz, Ahimsa; Kangayatkarasu, Nagulendran; Sayok, Alex; Hansen, Sune; Schouten, Greetje; Maulidia, Martha; Papargyropoulou, Effie; Tham, Mun Hou

    2016-01-01

    The recent Southeast Asian haze crisis has generated intense public scrutiny over the rate, methods and types of landscape change in the tropics. Debate has centred on the environmental impacts of large-scale agricultural expansion, particularly the associated loss of high carbon stock forest and

  11. Free energy landscape of electrocatalytic CO2 reduction to CO on aqueous FeN4 center embedded graphene studied by ab initio molecular dynamics simulations

    Science.gov (United States)

    Sheng, Tian; Sun, Shi-Gang

    2017-11-01

    Experiments have found that the porphyrin-like FeN4 site in Fe-N-C materials is highly efficient for the electrochemical reduction of CO2 into CO. In this work, we investigated the reduction mechanisms on FeN4 embedded graphene layer catalyst with some explicit water molecules by combining the constrained ab initio molecular dynamics simulations and thermodynamic integrations. The reaction free energy and electron transfer in each elementary step were identified. The initial CO2 activation was identified to go through the first electron transfer to form adsorbed CO2- anion and the CO desorption was the rate limiting step in the overall catalytic cycle.

  12. Review of Strategies for Thermal Efficiency in Landscape Planning of Cities for Conservation of Energy and Enhanced Climatic Resilience to Urban Warming

    Science.gov (United States)

    Imam, Aabshar U. K.; Banerjee, Uttam Kumar

    2017-09-01

    Thermal discomfort, increased energy consumption, and heat related stress are some of the most prominent consequences of urban warming. Instances of heat related deaths have been reported; the elderly and the poor remain especially vulnerable. Urban greening has often been cited as an economically efficient method for inducing ambient cooling. Consequently, increased impetus is given to provision of public green spaces. However, a general increase in urban green cover especially in the form of parks and green spaces may be inadequate to achieve desired results. This article serves to highlight the thermal heterogeneity of landcape elements and stresses on the need for strategic shade provision. The originality of this study lies in the fact that it provides a comparative review of energy conservation potential of public and private green spaces. It is found that large parks may not have substantial cooling effect on the indoor built environment. Moreover, people tend to spend more time indoors than outdoors. Thus the need for greening of private areas has become an undeniable climatic necessity. The potential of shade trees, green walls, and roof gardens for cooling of built environment are discussed with quantitative evidences of their thermal and economic benefits. Parameters incurring cost expenditure and weaknesses of the greening strategies are enumerated for enabling prudent selection/implementation of strategies. Proposals are generated to improve climatic resilience to urban warming and for diligent planning of cities.

  13. P-loop conformation governed crizotinib resistance in G2032R-mutated ROS1 tyrosine kinase: clues from free energy landscape.

    Directory of Open Access Journals (Sweden)

    Huiyong Sun

    2014-07-01

    Full Text Available Tyrosine kinases are regarded as excellent targets for chemical drug therapy of carcinomas. However, under strong purifying selection, drug resistance usually occurs in the cancer cells within a short term. Many cases of drug resistance have been found to be associated with secondary mutations in drug target, which lead to the attenuated drug-target interactions. For example, recently, an acquired secondary mutation, G2032R, has been detected in the drug target, ROS1 tyrosine kinase, from a crizotinib-resistant patient, who responded poorly to crizotinib within a very short therapeutic term. It was supposed that the mutation was located at the solvent front and might hinder the drug binding. However, a different fact could be uncovered by the simulations reported in this study. Here, free energy surfaces were characterized by the drug-target distance and the phosphate-binding loop (P-loop conformational change of the crizotinib-ROS1 complex through advanced molecular dynamics techniques, and it was revealed that the more rigid P-loop region in the G2032R-mutated ROS1 was primarily responsible for the crizotinib resistance, which on one hand, impaired the binding of crizotinib directly, and on the other hand, shortened the residence time induced by the flattened free energy surface. Therefore, both of the binding affinity and the drug residence time should be emphasized in rational drug design to overcome the kinase resistance.

  14. Precision cosmology and the landscape

    International Nuclear Information System (INIS)

    Bousso, Raphael; Bousso, Raphael

    2006-01-01

    After reviewing the cosmological constant problem--why is Lambda not huge?--I outline the two basic approaches that had emerged by the late 1980s, and note that each made a clear prediction. Precision cosmological experiments now indicate that the cosmological constant is nonzero. This result strongly favors the environmental approach, in which vacuum energy can vary discretely among widely separated regions in the universe. The need to explain this variation from first principles constitutes an observational constraint on fundamental theory. I review arguments that string theory satisfies this constraint, as it contains a dense discretuum of metastable vacua. The enormous landscape of vacua calls for novel, statistical methods of deriving predictions, and it prompts us to reexamine our description of spacetime on the largest scales. I discuss the effects of cosmological dynamics, and I speculate that weighting vacua by their entropy production may allow for prior-free predictions that do not resort to explicitly anthropic arguments

  15. Landscape Evolution Modelling-LAPSUS

    Energy Technology Data Exchange (ETDEWEB)

    Baartman, J. E. M.; Temme, A. J. A. M.; Schoorl, J. M.; Claessens, L.; Viveen, W.; Gorp, W. van; Veldkamp, A.

    2009-07-01

    Landscape evolution modelling can make the consequences of landscape evolution hypotheses explicit and theoretically allows for their falsification and improvement. ideally, landscape evolution models (LEMs) combine the results of all relevant landscape forming processes into an ever-adapting digital landscape (e.g. DEM). These processes may act on different spatial and temporal scales. LAPSUS is such a LEM. Processes that have in different studies been included in LAPSUS are water erosion and deposition, landslide activity, creep, solidification, weathering, tectonics and tillage. Process descriptions are as simple and generic as possible, ensuring wide applicability. (Author) 25 refs.

  16. Landscape Evolution Modelling-LAPSUS

    International Nuclear Information System (INIS)

    Baartman, J. E. M.; Temme, A. J. A. M.; Schoorl, J. M.; Claessens, L.; Viveen, W.; Gorp, W. van; Veldkamp, A.

    2009-01-01

    Landscape evolution modelling can make the consequences of landscape evolution hypotheses explicit and theoretically allows for their falsification and improvement. ideally, landscape evolution models (LEMs) combine the results of all relevant landscape forming processes into an ever-adapting digital landscape (e.g. DEM). These processes may act on different spatial and temporal scales. LAPSUS is such a LEM. Processes that have in different studies been included in LAPSUS are water erosion and deposition, landslide activity, creep, solidification, weathering, tectonics and tillage. Process descriptions are as simple and generic as possible, ensuring wide applicability. (Author) 25 refs.

  17. Driving the Landscape

    Science.gov (United States)

    Haff, P. K.

    2012-12-01

    Technological modification of the earth's surface (e.g., agriculture, urbanization) is an old story in human history, but what about the future? The future of landscape in an accelerating technological world, beyond a relatively short time horizon, lies hidden behind an impenetrable veil of complexity. Sufficiently complex dynamics generates not only the trajectory of a variable of interest (e.g., vegetation cover) but also the environment in which that variable evolves (e.g., background climate). There is no way to anticipate what variables will define that environment—the dynamics creates its own variables. We are always open to surprise by a change of conditions we thought or assumed were fixed or by the appearance of new phenomena of whose possible existence we had been unaware or thought unlikely. This is especially true under the influence of technology, where novelty is the rule. Lack of direct long-term predictability of landscape change does not, however, mean we cannot say anything about its future. The presence of persistence (finite time scales) in a system means that prediction by a calibrated numerical model should be good for a limited period of time barring bad luck or faulty implementation. Short-term prediction, despite its limitations, provides an option for dealing with the longer-term future. If a computer-controlled car tries to drive itself from New York to Los Angeles, no conceivable (or possible) stand-alone software can be constructed to predict a priori the space-time trajectory of the vehicle. Yet the drive is normally completed easily by most drivers. The trip is successfully completed because each in a series of very short (linear) steps can be "corrected" on the fly by the driver, who takes her cues from the environment to keep the car on the road and headed toward its destination. This metaphor differs in a fundamental way from the usual notion of predicting geomorphic change, because it involves a goal—to reach a desired

  18. Conceiving Landscape through Film

    DEFF Research Database (Denmark)

    Farsø, Mads; Munck Petersen, Rikke

    2015-01-01

    This article shows how the media of film can be integrated, explored and can add value to architectural design studios and practice. It elucidates how film may offer an alternative position in architecture, where landscapes and cities are thought, planned and developed in closer relation...... to their spatial and sensory effects on humans. It underscores that the film camera can work as a kind of amplifier of how we, with our bodies, perceive space and project space. In the “Landscape Film” Studio at University of Copenhagen the film medium was tested as a combined registration and design tool...... for a new Nature Park south of Copenhagen. The final studio films and designs show how resonate recordings of sound, time and a bodily presence may simulate an Einfühling that inspires an alternative architecture of relations: the ambient, the changeable and the volatile. They also emphasize that an ability...

  19. Landscape & Imagination: riflettere insieme

    Directory of Open Access Journals (Sweden)

    Mariella Zoppi

    2015-10-01

    Full Text Available In Paris, at La Villette University, was four-days of debate on 2-4 Mai 2013, in which faculty members of all the world discussed on methods and experiences in teaching landscape. The conference was organized in multiple sessions: history, theories, representation, process, science and governance. All the fields discussed were related to the main problem of the identity of territories in the landscape project -from the theories to the practices- and applied in a very large range of different situations: from the rural world between conservation and transformations to the coastal areas under the pressure of tourism, from the ecology in the city life renovation to the land use control and project by community and the emergency management in natural catastrophes.

  20. Climate change and the economics of biomass energy feedstocks in semi-arid agricultural landscapes: A spatially explicit real options analysis.

    Science.gov (United States)

    Regan, Courtney M; Connor, Jeffery D; Raja Segaran, Ramesh; Meyer, Wayne S; Bryan, Brett A; Ostendorf, Bertram

    2017-05-01

    The economics of establishing perennial species as renewable energy feedstocks has been widely investigated as a climate change adapted diversification option for landholders, primarily using net present value (NPV) analysis. NPV does not account for key uncertainties likely to influence relevant landholder decision making. While real options analysis (ROA) is an alternative method that accounts for the uncertainty over future conditions and the large upfront irreversible investment involved in establishing perennials, there have been limited applications of ROA to evaluating land use change decision economics and even fewer applications considering climate change risks. Further, while the influence of spatially varying climate risk on biomass conversion economic has been widely evaluated using NPV methods, effects of spatial variability and climate on land use change have been scarcely assessed with ROA. In this study we applied a simulation-based ROA model to evaluate a landholder's decision to convert land from agriculture to biomass. This spatially explicit model considers price and yield risks under baseline climate and two climate change scenarios over a geographically diverse farming region. We found that underlying variability in primary productivity across the study area had a substantial effect on conversion thresholds required to trigger land use change when compared to results from NPV analysis. Areas traditionally thought of as being quite similar in average productive capacity can display large differences in response to the inclusion of production and price risks. The effects of climate change, broadly reduced returns required for land use change to biomass in low and medium rainfall zones and increased them in higher rainfall areas. Additionally, the risks posed by climate change can further exacerbate the tendency for NPV methods to underestimate true conversion thresholds. Our results show that even under severe drying and warming where crop yield

  1. LANDSCAPE ECOLOGICAL METHOD TO STUDY AGRICULTURAL VEGETATION: SOME EXAMPLES FROM THE PO VALLEY

    Directory of Open Access Journals (Sweden)

    E. GIGLIO

    2006-01-01

    Full Text Available Vegetation is the most important landscape component, as regards to its ability to catch solar energy and to transform it, but also to shape the landscape, to structure the space, to create the fit environment for different animal species, to contribute to the maintenance of a correct metastability level for the landscape, etc. It is a biological system which acts under the constraints of the principles of the System Theory and owns the same properties of any other living system: so, it is a complex adaptive, hierarchical, dynamic, dissipative, self-organizing, self-transcendent, autocatalytic, self-maintaining system and follows the non-equilibrium thermodynamic. Its ecological state can be investigated through the comparison between “gathered data” (pathology and “normal data” (physiology for analogous types of vegetation. The Biological Integrated School of Landscape Ecology provides an integrated methodology to define ecological threshold limits of the different Agricultural Landscape types and applies to agricultural vegetation the specific part of the new methodology already tested to studying forests (the Landscape Biological Survey of Vegetation. Ecological quality, better and worst parameters, biological territorial capacity of vegetated corridors, agricultural field, poplar groves, orchards and woody remnant patches are investigated. Some examples from diverse agricultural landscapes of the Po Valley will be discussed. KEY WORDS: agricultural landscape, vegetation, landscape ecology, landscape health, Biological Integrated Landscape Ecology, Landscape Biological Survey of vegetation.

  2. LANDSCAPE ECOLOGICAL METHOD TO STUDY AGRICULTURAL VEGETATION: SOME EXAMPLES FROM THE PO VALLEY

    Directory of Open Access Journals (Sweden)

    E. GIGLIO

    2006-05-01

    Full Text Available Vegetation is the most important landscape component, as regards to its ability to catch solar energy and to transform it, but also to shape the landscape, to structure the space, to create the fit environment for different animal species, to contribute to the maintenance of a correct metastability level for the landscape, etc. It is a biological system which acts under the constraints of the principles of the System Theory and owns the same properties of any other living system: so, it is a complex adaptive, hierarchical, dynamic, dissipative, self-organizing, self-transcendent, autocatalytic, self-maintaining system and follows the non-equilibrium thermodynamic. Its ecological state can be investigated through the comparison between “gathered data” (pathology and “normal data” (physiology for analogous types of vegetation. The Biological Integrated School of Landscape Ecology provides an integrated methodology to define ecological threshold limits of the different Agricultural Landscape types and applies to agricultural vegetation the specific part of the new methodology already tested to studying forests (the Landscape Biological Survey of Vegetation. Ecological quality, better and worst parameters, biological territorial capacity of vegetated corridors, agricultural field, poplar groves, orchards and woody remnant patches are investigated. Some examples from diverse agricultural landscapes of the Po Valley will be discussed. KEY WORDS: agricultural landscape, vegetation, landscape ecology, landscape health, Biological Integrated Landscape Ecology, Landscape Biological Survey of vegetation.

  3. Identification Of Minangkabau Landscape Characters

    Science.gov (United States)

    Asrina, M.; Gunawan, A.; Aris, Munandar

    2017-10-01

    Minangkabau is one of cultures in indonesia which occupies landscape intact. Landscape of Minangkabau have a very close relationship with the culture of the people. Uniqueness of Minangkabau culture and landscape forming an inseparable characterunity. The landscape is necessarily identified to know the inherent landscape characters. The objective of this study was to identify the character of the Minangkabau landscape characterizes its uniqueness. The study was conducted by using descriptive method comprised literature review and field observasion. Observed the landscape characters comprised two main features, they were major and minor features. Indetification of the features was conducted in two original areas (darek) of the Minangkabau traditional society. The research results showed that major features or natural features of the landscape were predominantly landform, landcover, and hidrology. All luhak (districts) of Minangkabau showed similar main features such as hill, canyon, lake, valley, and forest. The existence of natural features such as hills, canyon and valleys characterizes the nature of minangkabau landscape. Minor features formed by Minangkabau cultural society were agricultural land and settlement. Rumah gadang (big house) is one of famous minor features characterizes the Minangkabau culture. In addition, several historical artefacts of building and others structure may strengthen uniqueness of the Minangkabau landscape character, such as The royal palace, inscription, and tunnels.

  4. Visualizing phylogenetic tree landscapes.

    Science.gov (United States)

    Wilgenbusch, James C; Huang, Wen; Gallivan, Kyle A

    2017-02-02

    Genomic-scale sequence alignments are increasingly used to infer phylogenies in order to better understand the processes and patterns of evolution. Different partitions within these new alignments (e.g., genes, codon positions, and structural features) often favor hundreds if not thousands of competing phylogenies. Summarizing and comparing phylogenies obtained from multi-source data sets using current consensus tree methods discards valuable information and can disguise potential methodological problems. Discovery of efficient and accurate dimensionality reduction methods used to display at once in 2- or 3- dimensions the relationship among these competing phylogenies will help practitioners diagnose the limits of current evolutionary models and potential problems with phylogenetic reconstruction methods when analyzing large multi-source data sets. We introduce several dimensionality reduction methods to visualize in 2- and 3-dimensions the relationship among competing phylogenies obtained from gene partitions found in three mid- to large-size mitochondrial genome alignments. We test the performance of these dimensionality reduction methods by applying several goodness-of-fit measures. The intrinsic dimensionality of each data set is also estimated to determine whether projections in 2- and 3-dimensions can be expected to reveal meaningful relationships among trees from different data partitions. Several new approaches to aid in the comparison of different phylogenetic landscapes are presented. Curvilinear Components Analysis (CCA) and a stochastic gradient decent (SGD) optimization method give the best representation of the original tree-to-tree distance matrix for each of the three- mitochondrial genome alignments and greatly outperformed the method currently used to visualize tree landscapes. The CCA + SGD method converged at least as fast as previously applied methods for visualizing tree landscapes. We demonstrate for all three mtDNA alignments that 3D

  5. Incorporating Bioenergy in Sustainable Landscape Designs Workshop Two: Agricultural Landscapes

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-08-01

    The Bioenergy Technologies Office hosted two workshops on Incorporating Bioenergy in Sustainable Landscape Designs with Oak Ridge and Argonne National Laboratories in 2014. The second workshop focused on agricultural landscapes and took place in Argonne, IL from June 24—26, 2014. The workshop brought together experts to discuss how landscape design can contribute to the deployment and assessment of sustainable bioenergy. This report summarizes the discussions that occurred at this particular workshop.

  6. Energy

    International Nuclear Information System (INIS)

    Meister, F.; Ott, F.

    2002-01-01

    This chapter gives an overview of the current energy economy in Austria. The Austrian political aims of sustainable development and climate protection imply a reorientation of the Austrian energy policy as a whole. Energy consumption trends (1993-1998), final energy consumption by energy carrier (indexed data 1993-1999), comparative analysis of useful energy demand (1993 and 1999) and final energy consumption of renewable energy sources by sector (1996-1999) in Austria are given. The necessary measures to be taken in order to reduce the energy demand and increased the use of renewable energy are briefly mentioned. Figs. 5. (nevyjel)

  7. Energy

    International Nuclear Information System (INIS)

    Meister, F.

    2001-01-01

    This chapter of the environmental control report deals with the environmental impact of energy production, energy conversion, atomic energy and renewable energy. The development of the energy consumption in Austria for the years 1993 to 1999 is given for the different energy types. The development of the use of renewable energy sources in Austria is given, different domestic heat-systems are compared, life cycles and environmental balance are outlined. (a.n.)

  8. Integrated landscape initiatives in Europe

    DEFF Research Database (Denmark)

    García-Martín, María; Bieling, Claudia; Hart, Abigail

    2016-01-01

    Landscapes are linked to human well-being in a multitude of ways, some of which are challenged by global market forces and traditional management approaches. In response to this situation there has been a rise in local initiatives to sustain the values of landscape. The aim of this paper is to pr......Landscapes are linked to human well-being in a multitude of ways, some of which are challenged by global market forces and traditional management approaches. In response to this situation there has been a rise in local initiatives to sustain the values of landscape. The aim of this paper...... searches and canvassing of European umbrella organisations; followed by an online survey of representatives from the identified initiatives (n??=??71). Our results show that the most relevant characteristics of integrated landscape initiatives in Europe are: a holistic approach to landscape management...

  9. Flowscapes: Designing infrastructure as landscape

    OpenAIRE

    Nijhuis, S.; Jauslin, D.T.; Van der Hoeven, F.D.

    2015-01-01

    Social, cultural and technological developments of our society are demanding a fundamental review of the planning and design of its landscapes and infrastructures, in particular in relation to environmental issues and sustainability. Transportation, green and water infrastructures are important agents that facilitate processes that shape the built environment and its contemporary landscapes. With movement and flows at the core, these landscape infrastructures facilitate aesthetic, functional,...

  10. Modelling Geomorphic Systems: Landscape Evolution

    OpenAIRE

    Valters, Declan

    2016-01-01

    Landscape evolution models (LEMs) present the geomorphologist with a means of investigating how landscapes evolve in response to external forcings, such as climate and tectonics, as well as internal process laws. LEMs typically incorporate a range of different geomorphic transport laws integrated in a way that simulates the evolution of a 3D terrain surface forward through time. The strengths of LEMs as research tools lie in their ability to rapidly test many different hypotheses of landscape...

  11. The Value of Landscape Essence

    Directory of Open Access Journals (Sweden)

    Maria da Conceição Marques Freire

    2014-08-01

    Full Text Available A new approach to interpreting the landscape is examined by accepting its complexity through inductive reasoning. While attempting to identify the essence of the landscape in the city and municipality of Óbidos, Portugal, several architectural recommendations of Venturi (2004 have been adapted as a framework for understanding this landscape. These will then guide the process of landscape transformation through:•••using the concepts of closed and contained spaces and the concept of fluid space;•recognising the existence of interstitial open spaces;•using those elements which are common to the distinct typologies of space;•defining the components that should be respected and those that can be respected;•observing landscape as a whole , while emphasising the relationship between the parts and the whole; and•rejecting simplification in the landscape transformation process.valuing the ambiguity incorporating the complexity Underlying this approach is the belief that the process of transformation must be based on the essence of each landscape. This implies the use of elements and structures of the landscape which are related to ecological, morphological and cultural systems. These elements and structures represent points of reference which should be considered in the process of landscape transformation.

  12. Thermal Characteristics of Urban Landscapes

    Science.gov (United States)

    Luvall, Jeffrey C.; Quattrochi, Dale A.

    1998-01-01

    Although satellite data are very useful for analysis of the urban heat island effect at a coarse scale, they do not lend themselves to developing a better understanding of which surfaces across the city contribute or drive the development of the urban heat island effect. Analysis of thermal energy responses for specific or discrete surfaces typical of the urban landscape (e.g., asphalt, building rooftops, vegetation) requires measurements at a very fine spatial scale (i.e., less than 15 m) to adequately resolve these surfaces and their attendant thermal energy regimes. Additionally, very fine scale spatial resolution thermal infrared data, such as that obtained from aircraft, are very useful for demonstrating to planning officials, policy makers, and the general populace the benefits of the urban forest. These benefits include mitigating the urban heat island effect, making cities more aesthetically pleasing and more habitable environments, and aid in overall cooling of the community. High spatial resolution thermal data are required to quantify how artificial surfaces within the city contribute to an increase in urban heating and the benefit of cool surfaces (e.g., surface coatings that reflect much of the incoming solar radiation as opposed to absorbing it thereby lowering urban temperatures). The TRN (thermal response number) is a technique using aircraft remotely sensed surface temperatures to quantify the thermal response of urban surfaces. The TRN was used to quantify the thermal response of various urban surface types ranging from completely vegetated surfaces to asphalt and concrete parking lots for Huntsville, AL.

  13. Impressionist Landscape Cartography

    Science.gov (United States)

    Todd, Stella W.

    2018-05-01

    Cartography helps to show us the world in which we reside by providing us a framework to explore space. We can select myriad themes to represent what is relevant to our lives: physical characteristics, human behaviors, hazards, opportunities. Themes are represented on a continuum between real-world images and pure abstractions. How we define cartography and what we expect from it changes with society and technology. We are now inundated with data but we still struggle with expressing our personal geographic experiences through cartography. In this age of information we have become more cognizant of our individual experience of place and our need to determine our own paths and therefore create our own maps. In order to reflect our journey we can add individual details to cartographic products or generalize information to concentrate on what is meaningful to us. Since time and space are interrelated we experience geography by viewing the landscape as changing scenes over time. This experience is both spatial and temporal since we experience geography by moving through space. Experiencing each scene is a separate event. This paper expands the personalization of maps to include our impressions of the travel experience. Rather than add art to cartography it provides geographic reference to art. It explores the use of a series of quick sketches drawn while traveling along roads using a single drawing pad to produce a time series of interpreted landscapes. With the use of geographic time stamps from global positioning systems these sketches are converted from a drawing to a map documenting the path of movement. Although the map scale varies between sketch entries each scene impression can be linked to one or more maps of consistent scale. The result is an artistic piece that expresses a dynamic geographic experience that can be viewed in conjunction with more traditional maps. Unlike mental maps which are constructed from memory, these maps reflect our direct impressions

  14. Using graph approach for managing connectivity in integrative landscape modelling

    Science.gov (United States)

    Rabotin, Michael; Fabre, Jean-Christophe; Libres, Aline; Lagacherie, Philippe; Crevoisier, David; Moussa, Roger

    2013-04-01

    In cultivated landscapes, a lot of landscape elements such as field boundaries, ditches or banks strongly impact water flows, mass and energy fluxes. At the watershed scale, these impacts are strongly conditionned by the connectivity of these landscape elements. An accurate representation of these elements and of their complex spatial arrangements is therefore of great importance for modelling and predicting these impacts.We developped in the framework of the OpenFLUID platform (Software Environment for Modelling Fluxes in Landscapes) a digital landscape representation that takes into account the spatial variabilities and connectivities of diverse landscape elements through the application of the graph theory concepts. The proposed landscape representation consider spatial units connected together to represent the flux exchanges or any other information exchanges. Each spatial unit of the landscape is represented as a node of a graph and relations between units as graph connections. The connections are of two types - parent-child connection and up/downstream connection - which allows OpenFLUID to handle hierarchical graphs. Connections can also carry informations and graph evolution during simulation is possible (connections or elements modifications). This graph approach allows a better genericity on landscape representation, a management of complex connections and facilitate development of new landscape representation algorithms. Graph management is fully operational in OpenFLUID for developers or modelers ; and several graph tools are available such as graph traversal algorithms or graph displays. Graph representation can be managed i) manually by the user (for example in simple catchments) through XML-based files in easily editable and readable format or ii) by using methods of the OpenFLUID-landr library which is an OpenFLUID library relying on common open-source spatial libraries (ogr vector, geos topologic vector and gdal raster libraries). Open

  15. The Anti-Landscape

    DEFF Research Database (Denmark)

    There have always been some uninhabitable places, but in the last century human beings have produced many more of them. These anti-landscapes have proliferated to include the sandy wastes of what was once the Aral Sea, severely polluted irrigated lands, open pit mines, blighted nuclear zones...... that no longer sustain life. This history includes T. S. Eliot’s Wasteland and Cormac McCarthy’s The Road as well as air pollution, recycled railway lines, photography and landfills. It links theories of aesthetics, politics, tourism, history, geography, and literature into the new synthesis of the environmental...

  16. Landscapes of the Anthropocene

    DEFF Research Database (Denmark)

    Pawson, Eric; Christensen, Andreas Aagaard

    2014-01-01

    since the 1840s, when indigenous forests were transformed into improved landscapes of sown grass. The chapter is shaped by a broad question. What can be learned from this place about the ways in which people have exercised and are coming to terms with what Gibson-Graham and Roelvink describe as our...... of the shifting balance of ecological agency in favour of humans during the Anthropocene. Banks Peninsula on the east coast of New Zealand’s South Island was first settled by Polynesian peoples within the last few hundred years. The nature of their footprint contrasts with the dramatic change wrought by Europeans...

  17. Stonehenge and its Landscape

    Science.gov (United States)

    Ruggles, Clive L. N.

    In the 1960s and 1970s, Stonehenge polarized academic opinion between those (mainly astronomers) who claimed it demonstrated great astronomical sophistication and those (mainly archaeologists) who denied it had anything to do with astronomy apart from the solstitial alignment of its main axis. Now, several decades later, links to the annual passage of the sun are generally recognized as an essential part of the function and meaning not only of Stonehenge but also of several other nearby monuments, giving us important insights into beliefs and actions relating to the seasonal cycle by the prehistoric communities who populated this chalkland landscape in the third millennium BC Links to the moon remain more debatable.

  18. Reprogramming the chromatin landscape

    DEFF Research Database (Denmark)

    Miranda, Tina B; Voss, Ty C; Sung, Myong-Hee

    2013-01-01

    , mechanistic details defining the cellular interactions between ER and GR are poorly understood. We investigated genome-wide binding profiles for ER and GR upon coactivation and characterized the status of the chromatin landscape. We describe a novel mechanism dictating the molecular interplay between ER...... and GR. Upon induction, GR modulates access of ER to specific sites in the genome by reorganization of the chromatin configuration for these elements. Binding to these newly accessible sites occurs either by direct recognition of ER response elements or indirectly through interactions with other factors...

  19. Stochastic Hydrodynamic Synchronization in Rotating Energy Landscapes

    OpenAIRE

    Koumakis, N.; Di Leonardo, R.

    2013-01-01

    Hydrodynamic synchronization provides a general mechanism for the spontaneous emergence of coherent beating states in independently driven mesoscopic oscillators. A complete physical picture of those phenomena is of definite importance to the understanding of biological cooperative motions of cilia and flagella. Moreover, it can potentially suggest novel routes to exploit synchronization in technological applications of soft matter. We demonstrate that driving colloidal particles in rotating ...

  20. Quantum Adiabatic Optimization and Combinatorial Landscapes

    Science.gov (United States)

    Smelyanskiy, V. N.; Knysh, S.; Morris, R. D.

    2003-01-01

    In this paper we analyze the performance of the Quantum Adiabatic Evolution (QAE) algorithm on a variant of Satisfiability problem for an ensemble of random graphs parametrized by the ratio of clauses to variables, gamma = M / N. We introduce a set of macroscopic parameters (landscapes) and put forward an ansatz of universality for random bit flips. We then formulate the problem of finding the smallest eigenvalue and the excitation gap as a statistical mechanics problem. We use the so-called annealing approximation with a refinement that a finite set of macroscopic variables (verses only energy) is used, and are able to show the existence of a dynamic threshold gamma = gammad, beyond which QAE should take an exponentially long time to find a solution. We compare the results for extended and simplified sets of landscapes and provide numerical evidence in support of our universality ansatz.

  1. Statistical predictions from anarchic field theory landscapes

    International Nuclear Information System (INIS)

    Balasubramanian, Vijay; Boer, Jan de; Naqvi, Asad

    2010-01-01

    Consistent coupling of effective field theories with a quantum theory of gravity appears to require bounds on the rank of the gauge group and the amount of matter. We consider landscapes of field theories subject to such to boundedness constraints. We argue that appropriately 'coarse-grained' aspects of the randomly chosen field theory in such landscapes, such as the fraction of gauge groups with ranks in a given range, can be statistically predictable. To illustrate our point we show how the uniform measures on simple classes of N=1 quiver gauge theories localize in the vicinity of theories with certain typical structures. Generically, this approach would predict a high energy theory with very many gauge factors, with the high rank factors largely decoupled from the low rank factors if we require asymptotic freedom for the latter.

  2. Editorial: Mapping the Intellectual Landscape of Landscape and Urban Planning

    Science.gov (United States)

    Paul H. Gobster; Wei-Ning. Xiang

    2012-01-01

    Maps are central to our understanding of landscapes. When this Editorship began to revise the journal's Aims and Scope for presentation in a forthcoming editorial, we sought ways in which we could identify the core knowledge base and boundaries, however permeable, of what the journal community considers to be Landscape and Urban Planning (LAND). Strategically, we...

  3. Landscape Painting in Evaluation of Changes in Landscape

    Czech Academy of Sciences Publication Activity Database

    Lacina, Jan; Halas, Petr

    2015-01-01

    Roč. 8, č. 2 (2015), s. 60-68 ISSN 1803-2427 Institutional support: RVO:68145535 Keywords : landscape painting * landscape ecology * land-use changes * biodiversity Subject RIV: DE - Earth Magnetism, Geodesy, Geography http://www.degruyter.com/view/j/jlecol.2015.8.issue-2/jlecol-2015-0009/jlecol-2015-0009. xml

  4. Cultural Landscape and Migration

    Directory of Open Access Journals (Sweden)

    Gunnar Haaland

    2011-04-01

    Full Text Available This paper focus on the way Nepalese migrants in Myanmar use features of the natural environment in their homeland in metaphoric constructions of a cultural landscape expressing ethnic identity. It is through such "symbolic work" that perceptions of "ethnoscapes" are shaped and indoctrinated. Although the appeal is to symbols that can serve to foster the importance of Nepaliness as a basis for belonging to an imagined community, this does not mean that the caste/ethnicity interaction boundaries are broken down. It does mean however that sectors of activities where such boundaries are made relevant have been changed and so has the cultural content organized through such interaction boundaries. Ethnoscapes do not exist by themselves from a 'primordial' past; they require ongoing expression and confirmation. Features of a natural environment most migrants have never seen is used as sources for spinning compelling webs of significance extolling the values of belonging to a group that shares a common past in that environment. I shall here present material of an ethnoscape very different from what is experienced in Nepal, namely Nepalese multi-caste/ethnic communities among Kachins, Shans, Burmese, Indian and Chinese traders in the Kachin state of Northern Myanmar. Keywords: Nepali migrants; Myanmar; ethnic identity; cultural landscape DOI: 10.3126/dsaj.v4i0.4515 Dhaulagiri Journal of Sociology and Anthropology Vol.4 2010 pp.99-110

  5. The Data Science Landscape

    Science.gov (United States)

    Mentzel, C.

    2017-12-01

    Modern scientific data continue to increase in volume, variety, and velocity, and though the hype of big data has subsided, its usefulness for scientific discovery has only just begun. Harnessing these data for new insights, more efficient decision making, and other mission critical uses requires a combination of skills and expertise, often labeled data science. Data science can be thought of as a combination of statistics, computation and the domain from which the data relate, and so is a true interdisciplinary pursuit. Though it has reaped large benefits in companies able to afford the high cost of the severely limited talent pool, it suffers from lack of support in mission driven organizations. Not purely in any one historical field, data science is proving difficult to find a home in traditional university academic departments and other research organizations. The landscape of data science efforts, from academia, industry and government, can be characterized as nascent, enthusiastic, uneven, and highly competitive. Part of the challenge in documenting these trends is the lack of agreement about what data science is, and who is a data scientist. Defining these terms too closely and too early runs the risk of cutting off a tremendous amount of productive creativity, but waiting too long leaves many people without a sustainable career, and many organizations without the necessary skills to gain value from their data. This talk will explore the landscape of data science efforts in the US, including how organizations are building and sustaining data science teams.

  6. Landscape Evolution of Titan

    Science.gov (United States)

    Moore, Jeffrey

    2012-01-01

    Titan may have acquired its massive atmosphere relatively recently in solar system history. The warming sun may have been key to generating Titan's atmosphere over time, starting from a thin atmosphere with condensed surface volatiles like Triton, with increased luminosity releasing methane, and then large amounts of nitrogen (perhaps suddenly), into the atmosphere. This thick atmosphere, initially with much more methane than at present, resulted in global fluvial erosion that has over time retreated towards the poles with the removal of methane from the atmosphere. Basement rock, as manifested by bright, rough, ridges, scarps, crenulated blocks, or aligned massifs, mostly appears within 30 degrees of the equator. This landscape was intensely eroded by fluvial processes as evidenced by numerous valley systems, fan-like depositional features and regularly-spaced ridges (crenulated terrain). Much of this bedrock landscape, however, is mantled by dunes, suggesting that fluvial erosion no longer dominates in equatorial regions. High midlatitude regions on Titan exhibit dissected sedimentary plains at a number of localities, suggesting deposition (perhaps by sediment eroded from equatorial regions) followed by erosion. The polar regions are mainly dominated by deposits of fluvial and lacustrine sediment. Fluvial processes are active in polar areas as evidenced by alkane lakes and occasional cloud cover.

  7. Urban landscape as palimpsest

    Directory of Open Access Journals (Sweden)

    Daniel-Gabriel Vâlceanu

    2014-12-01

    Full Text Available The current urban morphology and the identity building of the city construction can be designed as a palimpsest; the spatial development stages of urban systems represent the result of their evolution over time. The characteristics of urban palimpsest depend mainly on the emergent factors that influenced the territorial dynamics and the configuration of urban bodies. Urban life and its quality are directly influenced by spatial and temporal factors of the city evolution. For this reason the study aims to achieve a research to explain the concept of urban palimpsest and the current morphology of urban tissue because they are products of landscape transformations along the history. The current knowledge on urban palimpsest characteristics is very important and useful to plan the current and future evolution of urban systems. The case study presents a vast view on the history of spatial development and urban system as well as a dynamics of the landscape interconditioned by the elements of such development in the context of reference historical eras

  8. Norwegian millstone quarry landscapes

    Science.gov (United States)

    Heldal, Tom; Meyer, Gurli; Grenne, Tor

    2013-04-01

    Rotary querns and millstones were used in Norway since just after the Roman Period until the last millstone was made in the 1930s. Throughout all this time millstone mining was fundamental for daily life: millstones were needed to grind grain, our most important food source. We can find millstone quarries in many places in the country from coast to mountain. Some of them cover many square kilometers and count hundreds of quarries as physical testimonies of a long and great production history. Other quarries are small and hardly visible. Some of this history is known through written and oral tradition, but most of it is hidden and must be reconstructed from the traces we can find in the landscape today. The Millstone project has put these quarry landscapes on the map, and conducted a range of case studies, including characterization of archaeological features connected to the quarrying, interpretation of quarrying techniques and evolution of such and establishing distribution and trade patterns by the aid of geological provenance. The project also turned out to be a successful cooperation between different disciplines, in particular geology and archaeology.

  9. Energy

    International Nuclear Information System (INIS)

    Bobin, J.L.

    1996-01-01

    Object of sciences and technologies, energy plays a major part in economics and relations between nations. Jean-Louis Bobin, physicist, analyses the relations between man and energy and wonders about fears that delivers nowadays technologies bound to nuclear energy and about the fear of a possible shortage of energy resources. (N.C.). 17 refs., 14 figs., 2 tabs

  10. Operations of the LR56 radioactive liquid cask transport system at U.S. Department of Energy sites

    International Nuclear Information System (INIS)

    Davidson, J.S.; Hornstra, D.J.; Sazawal, V.K.; Clement, G.

    1996-01-01

    The LR56 cask system is licensed for use in France under Certificate of Compliance F/309/B(U)F for transport of 4,000-liter volumes of radioactive liquids. Three LR56 cask systems (with modifications for use at Department of Energy (DOE) sites) have been purchased for delivery at the Hanford Site, Oak Ridge National Laboratory (ORNL), and Savannah River Site (SRS). The LR56 cask systems will be used for on-site transfers of Type B quantities of radioactive liquid waste. The ORNL unit will also be used as a Type A packaging for transfers of radioactive liquids between DOE sites. This paper discusses LR56 operating features and the use of the cask system at the three DOE sites

  11. Sustainability, Smart Growth, and Landscape Architecture

    Science.gov (United States)

    Sustainability, Smart Growth, and Landscape Architecture is an overview course for landscape architecture students interested in sustainability in landscape architecture and how it might apply to smart growth principles in urban, suburban, and rural areas

  12. Energy

    CERN Document Server

    Foland, Andrew Dean

    2007-01-01

    Energy is the central concept of physics. Unable to be created or destroyed but transformable from one form to another, energy ultimately determines what is and isn''t possible in our universe. This book gives readers an appreciation for the limits of energy and the quantities of energy in the world around them. This fascinating book explores the major forms of energy: kinetic, potential, electrical, chemical, thermal, and nuclear.

  13. Changing wind-power landscapes

    DEFF Research Database (Denmark)

    Möller, Bernd

    2006-01-01

    of determining the likely visual-impact on landscapes and population, taking into account that there is no clear threshold for perceived adverse visual-impact. A geographical information system (GIS) has been used to build a regional landscape model for Northern Jutland County, which is used to assess visibility...

  14. Marc Treib: Representing Landscape Architecture

    DEFF Research Database (Denmark)

    Braae, Ellen Marie

    2008-01-01

    The editor of Representing Landscape Architecture, Marc Treib, argues that there is good reason to evaluate the standard practices of representation that landscape architects have been using for so long. In the rush to the promised land of computer design these practices are now in danger of being...

  15. Caribbean landscapes and their biodiversity

    Science.gov (United States)

    A. E. Lugo; E. H. Helmer; E. Santiago Valentín

    2012-01-01

    Both the biodiversity and the landscapes of the Caribbean have been greatly modified as a consequence of human activity. In this essay we provide an overview of the natural landscapes and biodiversity of the Caribbean and discuss how human activity has affected both. Our Caribbean geographic focus is on the insular Caribbean and the biodiversity focus is on the flora,...

  16. Future landscapes: opportunities and challenges

    Science.gov (United States)

    John Stanturf

    2015-01-01

    The global magnitude of degraded and deforested areas is best approached by restoring landscapes. Heightened international perception of the importance of forests and trees outside forests (e.g., woodlands, on farms) demands new approaches to future landscapes. The current need for forest restoration is two billion ha; most opportunities are mosaic restoration in the...

  17. Landscape in a Lacquer Box

    Science.gov (United States)

    Savage, Martha

    2010-01-01

    A symbolic dry landscape garden of Eastern origin holds a special fascination for the author's middle-school students, which is why the author chose to create a project exploring this view of nature. A dry landscape garden, or "karesansui," is an arrangement of rocks, worn by nature and surrounded by a "sea" of sand, raked into patterns…

  18. Contingent Diversity on Anthropic Landscapes

    Directory of Open Access Journals (Sweden)

    William Balée

    2010-02-01

    Full Text Available Behaviorally modern human beings have lived in Amazonia for thousands of years. Significant dynamics in species turnovers due to human-mediated disturbance were associated with the ultimate emergence and expansion of agrarian technologies in prehistory. Such disturbances initiated primary and secondary landscape transformations in various locales of the Amazon region. Diversity in these locales can be understood by accepting the initial premise of contingency, expressed as unprecedented human agency and human history. These effects can be accessed through the archaeological record and in the study of living languages. In addition, landscape transformation can be demonstrated in the study of traditional knowledge (TK. One way of elucidating TK distinctions between anthropic and nonanthropic landscapes concerns elicitation of differential labeling of these landscapes and more significantly, elicitation of the specific contents, such as trees, occurring in these landscapes. Freelisting is a method which can be used to distinguish the differential species compositions of landscapes resulting from human-mediated disturbance vs. those which do not evince records of human agency and history. The TK of the Ka’apor Indians of Amazonian Brazil as revealed in freelisting exercises shows differentiation of anthropogenic from high forests as well as a recognition of diversity in the anthropogenic forests. This suggests that the agents of human-mediated disturbance and landscape transformation in traditional Amazonia encode diversity and contingency into their TK, which encoding reflects past cultural influence on landscape and society over time.

  19. Fitness Landscapes of Functional RNAs

    Directory of Open Access Journals (Sweden)

    Ádám Kun

    2015-08-01

    Full Text Available The notion of fitness landscapes, a map between genotype and fitness, was proposed more than 80 years ago. For most of this time data was only available for a few alleles, and thus we had only a restricted view of the whole fitness landscape. Recently, advances in genetics and molecular biology allow a more detailed view of them. Here we review experimental and theoretical studies of fitness landscapes of functional RNAs, especially aptamers and ribozymes. We find that RNA structures can be divided into critical structures, connecting structures, neutral structures and forbidden structures. Such characterisation, coupled with theoretical sequence-to-structure predictions, allows us to construct the whole fitness landscape. Fitness landscapes then can be used to study evolution, and in our case the development of the RNA world.

  20. Conference on wind power development in the face of landscape and local project acceptability challenges

    International Nuclear Information System (INIS)

    Victoire Lejzerzon; Sauron, Claire; Villot, Marie; Ratzbor, Guenter; Tausch, Christian; Cagneaux, Bertrand; Jouneau, Agathe; Stemmer, Boris; Huebner, Gundula; Orozco-Souel, Paola; Lhermitte, Charles; Ferus, Elisabeth; Benezech, Philippe; Gunzelmann, Thomas

    2015-01-01

    The French-German office for Renewable energies (OFAEnR) organised a conference on n wind power development in the face of landscape and local project acceptability challenges. In the framework of this French-German exchange of experience, participants addressed the following points: the conciliation between landscape protection and wind power development, the definition of landscape environmental quality criteria, the needs and usages of the departments in charge of the treatment of landscape studies in France, the socio-psychological approach of the local acceptability of wind farm projects, the re-powering tool for the improvement of the wind farm integration in the landscape, and the conciliation between the monuments maintenance and wind power development. This document brings together the available presentations (slides) made during this event: 1 - Conciliating landscape protection and wind power development goals in France (Marie Villot); 2 - Wind turbines: Conflicts between development goals, landscape and acceptance - Perception and criteria (Guenter Ratzbor); 3 - Bayern's wind power atlas: a planning tool which takes into account the landscape aspects (Christian Tausch); 4 - Landscape assessment in wind farms projects: what and how to do in French administrative procedures? (Bertrand Cagneaux); 5 - Methods for evaluation of landscape for wind farms projects - A French project developer's feedback (Agathe Jouneau); 6 - Landscape Assessment: Methods from German Landscape Practice (Boris Stemmer); 7 - Acceptance of Wind Turbines - Social Psychological Research (Gundula Huebner); 8 - Local consultation: who to involve, when and how? (Paola Orozco-Souel); 9 - Local acceptability: what dialogue concepts and strategies, and how to manage wind energy objection (Charles Lhermitte); 10 - Re-powering and landscape: chances and limits (Elisabeth Ferus); 11 - Wind power and cultural heritage: consultation and dialogue to succeed (Philippe Benezech); 12

  1. A Classification of Landscape Services to Support Local Landscape Planning

    Directory of Open Access Journals (Sweden)

    María Vallés-Planells

    2014-03-01

    Full Text Available The ecosystem services approach has been proven successful to measure the contributions of nature and greenery to human well-being. Ecosystems have an effect on quality of life, but landscapes also, as a broader concept, may contribute to people's well-being. The concept of landscape services, compared to ecosystem services, involves the social dimension of landscape and the spatial pattern resulting from both natural and human processes in the provision of benefits for human-well being. Our aim is to develop a classification for landscape services. The proposed typology of services is built on the Common International Classification of Ecosystem Services (CICES and on a critical review of existing literature on human well-being dimensions, existing ecosystem service classifications, and landscape perception. Three themes of landscape services are defined, each divided into several groups: provisioning, regulation and maintenance, cultural and social life fulfillment, with the latter focusing on health, enjoyment, and personal and social fulfillment. A special emphasis is made on cultural services, which are especially important when applied to landscape and which have received less attention.

  2. The European nanometrology landscape.

    Science.gov (United States)

    Leach, Richard K; Boyd, Robert; Burke, Theresa; Danzebrink, Hans-Ulrich; Dirscherl, Kai; Dziomba, Thorsten; Gee, Mark; Koenders, Ludger; Morazzani, Valérie; Pidduck, Allan; Roy, Debdulal; Unger, Wolfgang E S; Yacoot, Andrew

    2011-02-11

    This review paper summarizes the European nanometrology landscape from a technical perspective. Dimensional and chemical nanometrology are discussed first as they underpin many of the developments in other areas of nanometrology. Applications for the measurement of thin film parameters are followed by two of the most widely relevant families of functional properties: measurement of mechanical and electrical properties at the nanoscale. Nanostructured materials and surfaces, which are seen as key materials areas having specific metrology challenges, are covered next. The final section describes biological nanometrology, which is perhaps the most interdisciplinary applications area, and presents unique challenges. Within each area, a review is provided of current status, the capabilities and limitations of current techniques and instruments, and future directions being driven by emerging industrial measurement requirements. Issues of traceability, standardization, national and international programmes, regulation and skills development will be discussed in a future paper.

  3. The European nanometrology landscape

    Science.gov (United States)

    Leach, Richard K.; Boyd, Robert; Burke, Theresa; Danzebrink, Hans-Ulrich; Dirscherl, Kai; Dziomba, Thorsten; Gee, Mark; Koenders, Ludger; Morazzani, Valérie; Pidduck, Allan; Roy, Debdulal; Unger, Wolfgang E. S.; Yacoot, Andrew

    2011-02-01

    This review paper summarizes the European nanometrology landscape from a technical perspective. Dimensional and chemical nanometrology are discussed first as they underpin many of the developments in other areas of nanometrology. Applications for the measurement of thin film parameters are followed by two of the most widely relevant families of functional properties: measurement of mechanical and electrical properties at the nanoscale. Nanostructured materials and surfaces, which are seen as key materials areas having specific metrology challenges, are covered next. The final section describes biological nanometrology, which is perhaps the most interdisciplinary applications area, and presents unique challenges. Within each area, a review is provided of current status, the capabilities and limitations of current techniques and instruments, and future directions being driven by emerging industrial measurement requirements. Issues of traceability, standardization, national and international programmes, regulation and skills development will be discussed in a future paper.

  4. The European nanometrology landscape

    International Nuclear Information System (INIS)

    Leach, Richard K; Boyd, Robert; Gee, Mark; Roy, Debdulal; Yacoot, Andrew; Burke, Theresa; Danzebrink, Hans-Ulrich; Dziomba, Thorsten; Koenders, Ludger; Dirscherl, Kai; Morazzani, Valerie; Pidduck, Allan; Unger, Wolfgang E S

    2011-01-01

    This review paper summarizes the European nanometrology landscape from a technical perspective. Dimensional and chemical nanometrology are discussed first as they underpin many of the developments in other areas of nanometrology. Applications for the measurement of thin film parameters are followed by two of the most widely relevant families of functional properties: measurement of mechanical and electrical properties at the nanoscale. Nanostructured materials and surfaces, which are seen as key materials areas having specific metrology challenges, are covered next. The final section describes biological nanometrology, which is perhaps the most interdisciplinary applications area, and presents unique challenges. Within each area, a review is provided of current status, the capabilities and limitations of current techniques and instruments, and future directions being driven by emerging industrial measurement requirements. Issues of traceability, standardization, national and international programmes, regulation and skills development will be discussed in a future paper. (topical review)

  5. The European nanometrology landscape

    Energy Technology Data Exchange (ETDEWEB)

    Leach, Richard K; Boyd, Robert; Gee, Mark; Roy, Debdulal; Yacoot, Andrew [National Physical Laboratory (United Kingdom); Burke, Theresa [European Society for Precision Engineering and Nanotechnology (United Kingdom); Danzebrink, Hans-Ulrich; Dziomba, Thorsten; Koenders, Ludger [Physikalisch-Technische Bundesanstalt (Germany); Dirscherl, Kai [Danish Fundamental Metrology (Denmark); Morazzani, Valerie [Laboratoire National de Metrologie et d' Essais (France); Pidduck, Allan [QinetiQ (United Kingdom); Unger, Wolfgang E S, E-mail: richard.leach@npl.co.uk [Federal Institute for Materials Research and Testing (Germany)

    2011-02-11

    This review paper summarizes the European nanometrology landscape from a technical perspective. Dimensional and chemical nanometrology are discussed first as they underpin many of the developments in other areas of nanometrology. Applications for the measurement of thin film parameters are followed by two of the most widely relevant families of functional properties: measurement of mechanical and electrical properties at the nanoscale. Nanostructured materials and surfaces, which are seen as key materials areas having specific metrology challenges, are covered next. The final section describes biological nanometrology, which is perhaps the most interdisciplinary applications area, and presents unique challenges. Within each area, a review is provided of current status, the capabilities and limitations of current techniques and instruments, and future directions being driven by emerging industrial measurement requirements. Issues of traceability, standardization, national and international programmes, regulation and skills development will be discussed in a future paper. (topical review)

  6. Data anonymization patent landscape

    Directory of Open Access Journals (Sweden)

    Mirjana Pejić Bach

    2017-01-01

    Full Text Available The omnipresent, unstoppable increase in digital data has led to a greater understanding of the importance of data privacy. Different approaches are used to implement data privacy. The goal of this paper is to develop a data anonymization patent landscape, by determining the following: (i the trend in data anonymization patenting, (ii the type of technical content protected in data anonymization, (iii the organizations and countries most active in patenting data anonymization know-how; and (iv the topics emerging most often in patent titles. Patents from the PatSeer database relating to data anonymization from 2001 to 2015 were analyzed. We used the longitudinal approach in combination with text mining techniques to develop a data anonymization patent landscape. The results indicated the following. The number of single patent families is growing with a high increase after 2010, thus indicating a positive trend in the area of patenting data anonymization solutions. The majority of patenting activities relate to the G Physics section. Organizations from the USA and Japan assigned the majority of patents related to data anonymization. The results of text mining indicate that the most often used word in titles of data anonymization patents are “anonym*, “method”, “data” and “system”. Several additional words that indicated the most frequent topics related to data anonymization were: “equipment”, “software”, “protection”, “identification”, or “encryption”, and specific topics such as “community”, “medical”, or “service”.

  7. Landscape functioning assessment using Landsat multispectral remote sensing data

    OpenAIRE

    Hesslerová, Petra

    2009-01-01

    The main aim of the dissertation thesis was to develop method, based on the use of multispectral satellite data and the theory of dissipation, allowing the analysis of landscape functioning. The theoretical basis is Prigogine's theory of dissipation and self-organization of structures in which energy dissipation is seen as the transformation of solar energy to other forms of energy. In this process the essential role play water availability and vegetation, which is able to bind solar radiatio...

  8. [Landscape classification: research progress and development trend].

    Science.gov (United States)

    Liang, Fa-Chao; Liu, Li-Ming

    2011-06-01

    Landscape classification is the basis of the researches on landscape structure, process, and function, and also, the prerequisite for landscape evaluation, planning, protection, and management, directly affecting the precision and practicability of landscape research. This paper reviewed the research progress on the landscape classification system, theory, and methodology, and summarized the key problems and deficiencies of current researches. Some major landscape classification systems, e. g. , LANMAP and MUFIC, were introduced and discussed. It was suggested that a qualitative and quantitative comprehensive classification based on the ideology of functional structure shape and on the integral consideration of landscape classification utility, landscape function, landscape structure, physiogeographical factors, and human disturbance intensity should be the major research directions in the future. The integration of mapping, 3S technology, quantitative mathematics modeling, computer artificial intelligence, and professional knowledge to enhance the precision of landscape classification would be the key issues and the development trend in the researches of landscape classification.

  9. Landscape characterization and biodiversity research

    Energy Technology Data Exchange (ETDEWEB)

    Dale, V.H. [Oak Ridge National Lab., TN (United States); Offerman, H. [Univ. of Maryland, College Park, MD (United States). Geography Dept.; Frohn, R. [Univ. of California, Santa Barbara, CA (United States); Gardner, R.H. [Appalachian Environmental Lab., Frostburg, MD (United States)

    1995-03-01

    Rapid deforestation often produces landscape-level changes in forest characteristics and structure, including area, distribution, and forest habitat types. Changes in landscape pattern through fragmentation or aggregation of natural habitats can alter patterns of abundance for single species and entire communities. Examples of single-species effects include increased predation along the forest edge, the decline in the number of species with poor dispersal mechanisms, and the spread of exotic species that have deleterious effects (e.g., gypsy moth). A decrease in the size and number of natural habitat patches increases the probability of local extirpation and loss of diversity of native species, whereas a decline in connectivity between habitat patches can negatively affect species persistence. Thus, there is empirical justification for managing entire landscapes, not just individual habitat types, in order to insure that native plant and animal diversity is maintained. A landscape is defined as an area composed of a mosaic of interacting ecosystems, or patches, with the heterogeneity among the patches significantly affecting biotic and abiotic processes in the landscape. Patches comprising a landscape are usually composed of discrete areas of relatively homogeneous environmental conditions and must be defined in terms of the organisms of interest. A large body of theoretical work in landscape ecology has provided a wealth of methods for quantifying spatial characteristics of landscapes. Recent advances in remote sensing and geographic information systems allow these methods to be applied over large areas. The objectives of this paper are to present a brief overview of common measures of landscape characteristics, to explore the new technology available for their calculation, to provide examples of their application, and to call attention to the need for collection of spatially-explicit field data.

  10. Landscape impact assessment for wind turbine development in Dyfed

    International Nuclear Information System (INIS)

    Blandford, C.; White, S.; Thomas, B.; Osment, F.

    1994-01-01

    The study aims to identify those areas in Dyfed where, in terms of landscape impact, local authorities might seek to exclude or encourage wind turbine development, provide guidelines which will assist local authorities in judging the impact of wind turbine developments on the landscape and provide a basis and framework for the preparation of planning policy guidelines for acceptable wind turbine and wind farm developments in Dyfed. The study context reviews current Government energy and planning policies for the encouragement of wind turbine developments. Dyfed County Council's relevant Structure Plan policies are also considered, as are the new draft policies relating directly to wind energy released by other authorities. The sizes and status of planning applications are summarised and the landscape implications and precedent set by the test case at Mynydd-y-Cemais is discussed. Public perception of wind power is reviewed in the context of research in Europe and the USA. (author)

  11. Landscape impact assessment of wind farm development in Dyfed

    International Nuclear Information System (INIS)

    Blandford, C.; White, S.; Garrad, A.D.; Morgan, C.A.

    1992-01-01

    Chris Blandford Associates, in association with Garrad Hassan and Partners, was commissioned to carry out a landscape impact assessment of wind turbine development in Dyfed. The study aims to identify those areas in Dyfed where, in terms of landscape impact, local authorities might seek either to exclude or encourage wind turbine development; provide guidelines to assist local authorities in judging the impact of wind turbine developments on the landscape; provide a basis and framework for the preparation of planning policy guidelines for acceptable wind turbine and wind farm developments in Dyfed. The study context reviews current Government energy and planning policies for the encouragement of wind turbine developments, as set out in the ''non-fossil fuel obligation'' and the draft planning policy guidance note for renewable energy published last December. (author)

  12. Energy

    CERN Document Server

    Robertson, William C

    2002-01-01

    Confounded by kinetic energy? Suspect that teaching about simple machines isn t really so simple? Exasperated by electricity? If you fear the study of energy is beyond you, this entertaining book will do more than introduce you to the topic. It will help you actually understand it. At the book s heart are easy-to-grasp explanations of energy basics work, kinetic energy, potential energy, and the transformation of energy and energy as it relates to simple machines, heat energy, temperature, and heat transfer. Irreverent author Bill Robertson suggests activities that bring the basic concepts of energy to life with common household objects. Each chapter ends with a summary and an applications section that uses practical examples such as roller coasters and home heating systems to explain energy transformations and convection cells. The final chapter brings together key concepts in an easy-to-grasp explanation of how electricity is generated. Energy is the second book in the Stop Faking It! series published by NS...

  13. Landscape services as boundary concept in landscape governance: Building social capital in collaboration and adapting the landscape

    NARCIS (Netherlands)

    Westerink, Judith; Opdam, Paul; Rooij, Van Sabine; Steingröver, Eveliene

    2017-01-01

    The landscape services concept provides a lens to study relations within the social-ecological networks that landscapes are, and to identify stakeholders as either providers or beneficiaries. However, landscape services can also be used as a boundary concept in collaborative landscape governance. We

  14. Thermal Infrared Remote Sensing for Analysis of Landscape Ecological Processes: Methods and Applications

    Science.gov (United States)

    Quattrochi, Dale A.; Luvall, Jeffrey C.

    1998-01-01

    Thermal Infrared (TIR) remote sensing data can provide important measurements of surface energy fluxes and temperatures, which are integral to understanding landscape processes and responses. One example of this is the successful application of TIR remote sensing data to estimate evapotranspiration and soil moisture, where results from a number of studies suggest that satellite-based measurements from TIR remote sensing data can lead to more accurate regional-scale estimates of daily evapotranspiration. With further refinement in analytical techniques and models, the use of TIR data from airborne and satellite sensors could be very useful for parameterizing surface moisture conditions and developing better simulations of landscape energy exchange over a variety of conditions and space and time scales. Thus, TIR remote sensing data can significantly contribute to the observation, measurement, and analysis of energy balance characteristics (i.e., the fluxes and redistribution of thermal energy within and across the land surface) as an implicit and important aspect of landscape dynamics and landscape functioning. The application of TIR remote sensing data in landscape ecological studies has been limited, however, for several fundamental reasons that relate primarily to the perceived difficulty in use and availability of these data by the landscape ecology community, and from the fragmentation of references on TIR remote sensing throughout the scientific literature. It is our purpose here to provide evidence from work that has employed TIR remote sensing for analysis of landscape characteristics to illustrate how these data can provide important data for the improved measurement of landscape energy response and energy flux relationships. We examine the direct or indirect use of TIR remote sensing data to analyze landscape biophysical characteristics, thereby offering some insight on how these data can be used more robustly to further the understanding and modeling of

  15. Multifunctional landscape practice and accessibility in manorial landscapes

    DEFF Research Database (Denmark)

    Brandt, Jesper; Svenningsen, Stig Roar; Christensen, Andreas Aagaard

    . However classical manorial estates seems to represent an opposite trend. Allthough working at the same market conditions as other large specialized holdings developed through the process of structural rationalization, they have often maintained and elaborated a land use strategy based on a multifunctional...... use of the potential ecosystem services present within their domain. The targeted combination of agriculture, forestry, hunting rents, rental housing, and a variety of recreational activities influences makes a certain public accessibility to an integrated part of this strategy, diverging from...... the multifunctional landscape strategy supporting a certain public access. A study of this thesis is presented based on an analysis of multifunctionality, landscape development and accessibility in Danish Manorial landscapes and eventual linkages between their multifunctional landscape strategy, their history...

  16. Beyond Landscape MacArchitecture: new languages, new landscapes

    Directory of Open Access Journals (Sweden)

    Simon Rackham

    1996-03-01

    Full Text Available The sine qua non of landscape architecture is respect for the genius loci, but even in the landscape, as in architecture and society more generally, a process of cultural homogenisation has been taking place. Against this process, a resurgence of interest in minority languages in Europe can be seen as an assertion of pride, and a desire to preserve difference. In Scotland, landscape architects are attempting to reinterpret Scottish and northern European urban design influences and materials: in effect to develop a new regional dialect for the new landscapes. Rooted in sound design principles and materials which respond to and reflect the climate, way of life and traditions of the place, design languages can communicate effectively about cultural values and differences.

  17. Decision making on fitness landscapes

    Science.gov (United States)

    Arthur, R.; Sibani, P.

    2017-04-01

    We discuss fitness landscapes and how they can be modified to account for co-evolution. We are interested in using the landscape as a way to model rational decision making in a toy economic system. We develop a model very similar to the Tangled Nature Model of Christensen et al. that we call the Tangled Decision Model. This is a natural setting for our discussion of co-evolutionary fitness landscapes. We use a Monte Carlo step to simulate decision making and investigate two different decision making procedures.

  18. Studying landscape architecture in Denmark

    DEFF Research Database (Denmark)

    Braae, Ellen Marie; Hare, Richard Andrew

    2010-01-01

    s demanded large numbers of landscape architects. Today landscape architecture education addresses current challenges of climate change and the need for sustainable development where an understanding of natural systems is seen as essential for future urbanisation processes in evermore innovative......Landscape architecture is a well-established profession in Denmark. From the early 20th Century the profession developed steadily. However, it was 1960 before a separate education was established. This proved timely as the immense physical development of the Danish welfare state of the 1970s and 80...

  19. Decision Making on Fitness Landscapes

    DEFF Research Database (Denmark)

    Arthur, Rudy; Sibani, Paolo

    2017-01-01

    We discuss fitness landscapes and how they can be modified to account for co-evolution. We are interested in using the landscape as a way to model rational decision making in a toy economic system. We develop a model very similar to the Tangled Nature Model of Christensen et. al. that we call...... the Tangled Decision Model. This is a natural setting for our discussion of co-evolutionary fitness landscapes. We use a Monte Carlo step to simulate decision making and investigate two different decision making procedures....

  20. Connecting Brabant's cover sand landscapes through landscape history

    Science.gov (United States)

    Heskes, Erik; van den Ancker, Hanneke; Jungerius, Pieter Dirk; Harthoorn, Jaap; Maes, Bert; Leenders, Karel; de Jongh, Piet; Kluiving, Sjoerd; van den Oetelaar, Ger

    2015-04-01

    Noord-Brabant has the largest variety of cover sand landscapes in The Netherlands, and probably in Western Europe. During the Last Ice Age the area was not covered by land ice and a polar desert developed in which sand dunes buried the existing river landscapes. Some of these polar dune landscapes experienced a geomorphological and soil development that remained virtually untouched up to the present day, such as the low parabolic dunes of the Strabrechtse Heide or the later and higher dunes of the Oisterwijkse Vennen. As Noord-Brabant lies on the fringe of a tectonic basin, the thickness of cover sand deposits in the Centrale Slenk, part of a rift through Europe, amounts up to 20 metres. Cover sand deposits along the fault lines cause the special phenomenon of 'wijst' to develop, in which the higher grounds are wetter than the boarding lower grounds. Since 4000 BC humans settled in these cover sand landscapes and made use of its small-scale variety. An example are the prehistoric finds on the flanks and the historic towns on top of the 'donken' in northwest Noord-Brabant, where the cover sand landscapes are buried by river and marine deposits and only the peaks of the dunes protrude as donken. Or the church of Handel that is built beside a 'wijst' source and a site of pilgrimage since living memory. Or the 'essen' and plaggen agriculture that developed along the stream valleys of Noord-Brabant from 1300 AD onwards, giving rise to geomorphological features as 'randwallen' and plaggen soils of more than a metre thickness. Each region of Brabant each has its own approach in attracting tourists and has not yet used this common landscape history to connect, manage and promote their territories. We propose a landscape-historical approach to develop a national or European Geopark Brabants' cover sand landscapes, in which each region focuses on a specific part of the landscape history of Brabant, that stretches from the Late Weichselian polar desert when the dune

  1. The scale of inflation in the landscape

    International Nuclear Information System (INIS)

    Pedro, F.G.; Westphal, A.

    2013-03-01

    We determine the frequency of regions of small-field inflation in the Wigner landscape as an approximation to random supergravities/type IIB flux compactifications. We show that small-field inflation occurs exponentially more often than large-field inflation The power of primordial gravitational waves from inflation is generically tied to the scale of inflation. For small-field models this is below observational reach. However, we find small-field inflation to be dominated by the highest inflationary energy scales compatible with a sub-Planckian field range. Hence, we expect a typical tensor-to-scalar ratio r∝O(10 -3 ) currently undetectable in upcoming CMB measurements.

  2. LANDSCAPE PLANNING IN UKRAINE: THE FIRST LANDSCAPE-PLANNING PROGRAM

    Directory of Open Access Journals (Sweden)

    Leonid Rudenko

    2013-01-01

    Full Text Available The paper presents the results of the first, in Ukraine; project on landscape planning widely accepted in European countries. Under the project implemented in 2010–2013, a landscape-planning program has been developed for the Cherkassy oblast. This is the first document of this kind in Ukraine. The program is mainly based on the experience of the German and Russian schools of landscape planning and on research and assessment conducted by the authors, which allowed identifying approaches to landscape planning, principles of the national policy, and characteristics and potential of environmentally friendly planning in Ukraine. The paper discusses the main phases of the work on the development of the landscape program for the oblast. It also identifies the main stages and key concepts and principles of landscape planning. The paper presents the results of integrated research on the identification and classification of conflicts in land use and the integral concept of the developmental goals for the oblast. The results can be the foundation for adopting management decisions and development of action plans for the lower hierarchal branches.

  3. Landscape externalities from onshore wind power

    International Nuclear Information System (INIS)

    Meyerhoff, Juergen; Ohl, Cornelia; Hartje, Volkmar

    2010-01-01

    The expansion of renewable energy is a central element of the German Federal Government's climate and energy policy. The target for 2020 is to produce 30% of the electricity from renewable energies. Wind power has been selected to be a major contributor to this change. Replacing old wind turbines by modern ones and building new turbines on land will be crucial in meeting this target. However, the expansion of onshore wind power is not universally accepted. In several regions of Germany residents are protesting against setting up new wind turbines. To determine the negative effects two choice experiments were applied in Westsachsen and Nordhessen, Germany. In both regions the externalities of wind power generation until 2020 based on today's state of technology were measured. The results show that negative landscape externalities would result from expanding wind power generation. Using latent class models three different groups of respondents experiencing different degrees of externalities were identified.

  4. Perspectives on landscape identity, a conceptual challenge

    NARCIS (Netherlands)

    Stobbelaar, D.J.; Pedroli, B.

    2011-01-01

    The concept of landscape identity is often referred to in landscape policy and planning. A clear definition of the concept is lacking however. This is problematic because the term ‘landscape identity’ can have many different meanings and thus easily lead to confusion. We define landscape identity as

  5. Bipolarity and Ambivalence in Landscape Architecture

    NARCIS (Netherlands)

    Koh, J.

    2010-01-01

    Our discipline of landscape architecture contains bipolarity, not only in terms of landscape and architecture but also because the idea of landscape is both aesthetic and scientific. Furthermore, within landscape architecture there is a gap between design (as implied by architecture) and planning

  6. Energy

    International Nuclear Information System (INIS)

    1975-10-01

    On the occasion of the World Environment Day the Norwegian Ministry for the Environment held a conference on growth problems in energy consumption. The themes which were treated were energy conservation, hydroelectric power, the role of nuclear power, radioactive waste disposal, fossil fuel resources, ecological limits, pollution and international aspects. Nuclear energy forms the main theme of one lecture and an aspect of several others. (JIW)

  7. Energy

    OpenAIRE

    Torriti, Jacopo

    2016-01-01

    The impact of energy policy measures has been assessed with various appraisal and evaluation tools since the 1960s. Decision analysis, environmental impact assessment and strategic environmental assessment are all notable examples of progenitors of Regulatory Impact Assessment (RIA) in the assessment of energy policies, programmes and projects. This chapter provides overview of policy tools which have been historically applied to assess the impacts of energy policies, programmes and projects....

  8. Reheating-volume measure in the string theory landscape

    International Nuclear Information System (INIS)

    Winitzki, Sergei

    2008-01-01

    I recently proposed the ''reheating-volume'' (RV) prescription as a possible solution to the measure problem in ''multiverse'' cosmology. The goal of this work is to extend the RV measure to scenarios involving bubble nucleation, such as the string theory landscape. In the spirit of the RV prescription, I propose to calculate the distribution of observable quantities in a landscape that is conditioned in probability to nucleate a finite total number of bubbles to the future of an initial bubble. A general formula for the relative number of bubbles of different types can be derived. I show that the RV measure is well defined and independent of the choice of the initial bubble type, as long as that type supports further bubble nucleation. Applying the RV measure to a generic landscape, I find that the abundance of Boltzmann brains is always negligibly small compared with the abundance of ordinary observers in the bubbles of the same type. As an illustration, I present explicit results for a toy landscape containing four vacuum states, and for landscapes with a single high-energy vacuum and a large number of low-energy vacua.

  9. Energies

    International Nuclear Information System (INIS)

    2003-01-01

    In the framework of the National Debate on the energies in a context of a sustainable development some associations for the environment organized a debate on the nuclear interest facing the renewable energies. The first part presents the nuclear energy as a possible solution to fight against the greenhouse effect and the associated problem of the wastes management. The second part gives information on the solar energy and the possibilities of heat and electric power production. A presentation of the FEE (French wind power association) on the situation and the development of the wind power in France, is also provided. (A.L.B.)

  10. Multiple coupled landscapes and non-adiabatic dynamics with applications to self-activating genes.

    Science.gov (United States)

    Chen, Cong; Zhang, Kun; Feng, Haidong; Sasai, Masaki; Wang, Jin

    2015-11-21

    Many physical, chemical and biochemical systems (e.g. electronic dynamics and gene regulatory networks) are governed by continuous stochastic processes (e.g. electron dynamics on a particular electronic energy surface and protein (gene product) synthesis) coupled with discrete processes (e.g. hopping among different electronic energy surfaces and on and off switching of genes). One can also think of the underlying dynamics as the continuous motion on a particular landscape and discrete hoppings among different landscapes. The main difference of such systems from the intra-landscape dynamics alone is the emergence of the timescale involved in transitions among different landscapes in addition to the timescale involved in a particular landscape. The adiabatic limit when inter-landscape hoppings are fast compared to continuous intra-landscape dynamics has been studied both analytically and numerically, but the analytical treatment of the non-adiabatic regime where the inter-landscape hoppings are slow or comparable to continuous intra-landscape dynamics remains challenging. In this study, we show that there exists mathematical mapping of the dynamics on 2(N) discretely coupled N continuous dimensional landscapes onto one single landscape in 2N dimensional extended continuous space. On this 2N dimensional landscape, eddy current emerges as a sign of non-equilibrium non-adiabatic dynamics and plays an important role in system evolution. Many interesting physical effects such as the enhancement of fluctuations, irreversibility, dissipation and optimal kinetics emerge due to non-adiabaticity manifested by the eddy current illustrated for an N = 1 self-activator. We further generalize our theory to the N-gene network with multiple binding sites and multiple synthesis rates for discretely coupled non-equilibrium stochastic physical and biological systems.

  11. Flowscapes : Designing infrastructure as landscape

    NARCIS (Netherlands)

    Nijhuis, S.; Jauslin, D.T.; Van der Hoeven, F.D.

    2015-01-01

    Social, cultural and technological developments of our society are demanding a fundamental review of the planning and design of its landscapes and infrastructures, in particular in relation to environmental issues and sustainability. Transportation, green and water infrastructures are important

  12. Qualified Health Plan (QHP) Landscape

    Data.gov (United States)

    U.S. Department of Health & Human Services — QHP Landscape Files present basic information about certified Qualified Health Plans and Stand-alone Dental Plans for individuals-families and small businesses...

  13. The evolving landscape of banking

    NARCIS (Netherlands)

    Boot, A.W.A.; Marinč, M.

    2008-01-01

    The structure of the financial services industry is in flux. Liberalization, deregulation, and advances in information technology have changed the financial landscape dramatically. Interbank competition has heated up and banks face increasing competition from nonbanking financial institutions and

  14. Greenhouse warming and landscape care

    Science.gov (United States)

    Kevin T. Smith

    2009-01-01

    Climate change is one of the few truly planetary processes that influence the assessments and actions of governments and of everyday citizens. Principles and practices of ecological landscaping fit well with concern about hte effects of climate change.

  15. Geographic Information Systems for Assessing Existing and Potential Bio-energy Resources: Their Use in Determining Land Use and Management Options which Minimize Ecological and Landscape Impacts in Rural Areas

    Science.gov (United States)

    Jackman, A. E.; Fabos, J. G.; Carlozzi, C. C.

    1982-01-01

    A management construct is described which forms part of an overall landscape ecological planning model which has as a principal objective the extension of the traditional descriptive land use mapping capabilities of geographic information systems into land management realms. It is noted that geographic information systems appear to be moving to more comprehensive methods of data handling and storage, such as relational and hierarchical data management systems, and a clear need has simultaneously arisen therefore for planning assessment techniques and methodologies which can actually use such complex levels of data in a systematic, yet flexible and scenario dependent way. The descriptive of mapping method proposed broaches such issues and utilizes a current New England bioenergy scenario, stimulated by the use of hardwoods for household heating purposes established in the post oil crisis era and the increased awareness of the possible landscape and ecological ramifications of the continued increasing use of the resource.

  16. Titan Polar Landscape Evolution

    Science.gov (United States)

    Moore, Jeffrey M.

    2016-01-01

    With the ongoing Cassini-era observations and studies of Titan it is clear that the intensity and distribution of surface processes (particularly fluvial erosion by methane and Aeolian transport) has changed through time. Currently however, alternate hypotheses substantially differ among specific scenarios with respect to the effects of atmospheric evolution, seasonal changes, and endogenic processes. We have studied the evolution of Titan's polar region through a combination of analysis of imaging, elevation data, and geomorphic mapping, spatially explicit simulations of landform evolution, and quantitative comparison of the simulated landscapes with corresponding Titan morphology. We have quantitatively evaluated alternate scenarios for the landform evolution of Titan's polar terrain. The investigations have been guided by recent geomorphic mapping and topographic characterization of the polar regions that are used to frame hypotheses of process interactions, which have been evaluated using simulation modeling. Topographic information about Titan's polar region is be based on SAR-Topography and altimetry archived on PDS, SAR-based stereo radar-grammetry, radar-sounding lake depth measurements, and superposition relationships between geomorphologic map units, which we will use to create a generalized topographic map.

  17. PSEUDO-CODEWORD LANDSCAPE

    Energy Technology Data Exchange (ETDEWEB)

    CHERTKOV, MICHAEL [Los Alamos National Laboratory; STEPANOV, MIKHAIL [Los Alamos National Laboratory

    2007-01-10

    The authors discuss performance of Low-Density-Parity-Check (LDPC) codes decoded by Linear Programming (LP) decoding at moderate and large Signal-to-Noise-Ratios (SNR). Frame-Error-Rate (FER) dependence on SNR and the noise space landscape of the coding/decoding scheme are analyzed by a combination of the previously introduced instanton/pseudo-codeword-search method and a new 'dendro' trick. To reduce complexity of the LP decoding for a code with high-degree checks, {ge} 5, they introduce its dendro-LDPC counterpart, that is the code performing identifically to the original one under Maximum-A-Posteriori (MAP) decoding but having reduced (down to three) check connectivity degree. Analyzing number of popular LDPC codes and their dendro versions performing over the Additive-White-Gaussian-Noise (AWGN) channel, they observed two qualitatively different regimes: (i) error-floor sets early, at relatively low SNR, and (ii) FER decays with SNR increase faster at moderate SNR than at the largest SNR. They explain these regimes in terms of the pseudo-codeword spectra of the codes.

  18. Saddleworth, Responding to a Landscape

    OpenAIRE

    Murray, Matthew

    2017-01-01

    Matthew Murray's Landscape publication Saddleworth, Responding To A Landscape. Forward by Martin Barnes Senior Curator of Photographs at The Victoria and Albert Museum, London, Artist Richard Billingham and Maartje van den Heuvel Curator Photography and Media Culture -Leiden Institute. \\ud \\ud ‘Every trip I have taken to Saddleworth Moor over four years has encapsulated each season, weather and cloud pattern, rain, sunshine, snow, early morning clear skies and the sense of the bitter cold of ...

  19. The Industrial Engineering publishing landscape

    OpenAIRE

    Claasen, Schalk

    2012-01-01

    Looking at the Industrial Engineering publishing landscape through the window of Google Search, an interesting panorama unfolds. The view that I took is actually just a peek and therefore my description of what I saw is not meant to be comprehensive. The African landscape is empty except for the South African Journal of Industrial Engineering (SAJIE). This is an extraordinary situation if compared to the South American continent where there are Industrial Engineering journals in at least ...

  20. The landscapes of tourism space

    OpenAIRE

    Włodarczyk, Bogdan

    2009-01-01

    The author attempts to define the term ‘tourism landscape’. It is treated as an important attribute of tourism space therefore, apart from its definition, the author presents its characteristic features and various types of such spaces with differing tourism landscapes. The landscapes of tourism space are treated not only as tourism assets or attractions, but also as the consequences of tourism activity on the natural and cultural environment.

  1. Editorial: Entropy in Landscape Ecology

    Directory of Open Access Journals (Sweden)

    Samuel A. Cushman

    2018-04-01

    Full Text Available Entropy and the second law of thermodynamics are the central organizing principles of nature, but the ideas and implications of the second law are poorly developed in landscape ecology. The purpose of this Special Issue “Entropy in Landscape Ecology” in Entropy is to bring together current research on applications of thermodynamics in landscape ecology, to consolidate current knowledge and identify key areas for future research. The special issue contains six articles, which cover a broad range of topics including relationships between entropy and evolution, connections between fractal geometry and entropy, new approaches to calculate configurational entropy of landscapes, example analyses of computing entropy of landscapes, and using entropy in the context of optimal landscape planning. Collectively these papers provide a broad range of contributions to the nascent field of ecological thermodynamics. Formalizing the connections between entropy and ecology are in a very early stage, and that this special issue contains papers that address several centrally important ideas, and provides seminal work that will be a foundation for the future development of ecological and evolutionary thermodynamics.

  2. Landscape Visualisation on the Internet

    Science.gov (United States)

    Imhof, M. P.; Cox, M. T.; Harvey, D. W.; Heemskerk, G. E.; Pettit, C. J.

    2012-07-01

    The Victorian Resources Online (VRO) website (http://www.dpi.vic.gov.au/vro) is the principal means for accessing landscapebased information in Victoria. In this paper we introduce a range of online landscape visualisations that have been developed to enhance existing static web content around the nature and distribution of Victoria's landforms and soils as well as associated processes. Flash is used to develop online visualisations that include interactive landscape panoramas, animations of soil and landscape processes and videos of experts explaining features in the field as well as landscape "flyovers". The use of interactive visualisations adds rich information multimedia content to otherwise static pages and offers the potential to improve user's appreciation and understanding of soil and landscapes. Visualisation is becoming a key component of knowledge management activities associated with VRO - proving useful for both "knowledge capture" (from subject matter specialists) and "knowledge transfer" to a diverse user base. A range of useful visualisation products have been made available online, with varying degrees of interactivity and suited to a variety of users. The use of video files, animation and interactive visualisations is adding rich information content to otherwise static web pages. These information products offer new possibilities to enhance learning of landscapes and the effectiveness of these will be tested as the next phase of development.

  3. The Roles of Structural Order and Intermolecular Interactions in Determining Ionization Energies and Charge-Transfer State Energies in Organic Semiconductors

    KAUST Repository

    Graham, Kenneth; Ngongang Ndjawa, Guy Olivier; Conron, Sarah M.; Munir, Rahim; Vandewal, Koen; Chen, John J.; Sweetnam, Sean; Thompson, Mark E.; Salleo, Alberto; Mcgehee, Michael D.; Amassian, Aram

    2016-01-01

    The energy landscape in organic semiconducting materials greatly influences charge and exciton behavior, which are both critical to the operation of organic electronic devices. These energy landscapes can change dramatically depending on the phases

  4. Epigenetic Inheritance Across the Landscape

    Directory of Open Access Journals (Sweden)

    Amy Vaughn Whipple

    2016-10-01

    Full Text Available The study of epigenomic variation at the landscape-level in plants may add important insight to studies of adaptive variation. A major goal of landscape genomic studies is to identify genomic regions contributing to adaptive variation across the landscape. Heritable variation in epigenetic marks, resulting in transgenerational plasticity, can influence fitness-related traits. Epigenetic marks are influenced by the genome, the environment, and their interaction, and can be inherited independently of the genome. Thus, epigenomic variation likely influences the heritability of many adaptive traits, but the extent of this influence remains largely unknown. Here we summarize the relevance of epigenetic inheritance to ecological and evolutionary processes, and review the literature on landscape-level patterns of epigenetic variation. Landscape-level patterns of epigenomic variation in plants generally show greater levels of isolation by distance and isolation by environment then is found for the genome, but the causes of these patterns are not yet clear. Linkage between the environment and epigenomic variation has been clearly shown within a single generation, but demonstrating transgenerational inheritance requires more complex breeding and/or experimental designs. Transgenerational epigenetic variation may alter the interpretation of landscape genomic studies that rely upon phenotypic analyses, but should have less influence on landscape genomic approaches that rely upon outlier analyses or genome-environment associations. We suggest that multi-generation common garden experiments conducted across multiple environments will allow researchers to understand which parts of the epigenome are inherited, as well as to parse out the relative contribution of heritable epigenetic variation to the phenotype.

  5. Epigenetic Inheritance across the Landscape.

    Science.gov (United States)

    Whipple, Amy V; Holeski, Liza M

    2016-01-01

    The study of epigenomic variation at the landscape-level in plants may add important insight to studies of adaptive variation. A major goal of landscape genomic studies is to identify genomic regions contributing to adaptive variation across the landscape. Heritable variation in epigenetic marks, resulting in transgenerational plasticity, can influence fitness-related traits. Epigenetic marks are influenced by the genome, the environment, and their interaction, and can be inherited independently of the genome. Thus, epigenomic variation likely influences the heritability of many adaptive traits, but the extent of this influence remains largely unknown. Here, we summarize the relevance of epigenetic inheritance to ecological and evolutionary processes, and review the literature on landscape-level patterns of epigenetic variation. Landscape-level patterns of epigenomic variation in plants generally show greater levels of isolation by distance and isolation by environment then is found for the genome, but the causes of these patterns are not yet clear. Linkage between the environment and epigenomic variation has been clearly shown within a single generation, but demonstrating transgenerational inheritance requires more complex breeding and/or experimental designs. Transgenerational epigenetic variation may alter the interpretation of landscape genomic studies that rely upon phenotypic analyses, but should have less influence on landscape genomic approaches that rely upon outlier analyses or genome-environment associations. We suggest that multi-generation common garden experiments conducted across multiple environments will allow researchers to understand which parts of the epigenome are inherited, as well as to parse out the relative contribution of heritable epigenetic variation to the phenotype.

  6. Concavity Theorems for Energy Surfaces

    OpenAIRE

    Giraud, B. G.; Karataglidis, S.

    2011-01-01

    Concavity properties prevent the existence of significant landscapes in energy surfaces obtained by strict constrained energy minimizations. The inherent contradiction is due to fluctuations of collective coordinates. A solution to those fluctuations is given.

  7. Shapes of tree representations of spin-glass landscapes

    International Nuclear Information System (INIS)

    Hordijk, Wim; Fontanari, Jose F; Stadler, Peter F

    2003-01-01

    Much of the information about the multi-valley structure of disordered spin systems can be convened in a simple tree structure - a barrier tree - the leaves and internal nodes of which represent, respectively, the local minima and the lowest energy saddles connecting those minima. Here we apply several statistics used in the study of phylogenetic trees to barrier trees that result from the energy landscapes of p-spin models. These statistics give information about the shape of these barrier trees, in particular about balance and symmetry. We then ask if they can be used to classify different types of landscapes, compare them with results obtained from random trees, and investigate the structure of subtrees of the barrier trees. We conclude that at least one of the used statistics is capable of distinguishing different types of landscapes, that the barrier trees from p-spin energy landscapes are quite different from random trees, and that subtrees of barrier trees do not reflect the overall tree structure, but their structure is correlated with their 'depth' in the tree

  8. Buildings interoperability landscape - Draft

    Energy Technology Data Exchange (ETDEWEB)

    Hardin, Dave B. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Stephan, Eric G. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Wang, Weimin [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Corbin, Charles D. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Widergren, Steven E. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

    2015-02-01

    Buildings are an integral part of our nation’s energy economy. The advancement in information and communications technology (ICT) has revolutionized energy management in industrial facilities and large commercial buildings. As ICT costs decrease and capabilities increase, buildings automation and energy management features are transforming the small-medium commercial and residential buildings sectors. A vision of a connected world in which equipment and systems within buildings coordinate with each other to efficiently meet their owners’ and occupants’ needs, and where buildings regularly transact business with other buildings and service providers (such as gas and electric service providers) is emerging. However, while the technology to support this collaboration has been demonstrated at various degrees of maturity, the integration frameworks and ecosystems of products that support the ability to easily install, maintain, and evolve building systems and their equipment components are struggling to nurture the fledging business propositions of their proponents.

  9. Landscape Ecology and problems of European cultural landscapes

    DEFF Research Database (Denmark)

    Brandt, Jesper

    2011-01-01

    by practical problems of European cultural – especial agricultural – landscapes since the rise of the environmental movement. Central themes have been the consequences of technological and structural changes within European agriculture for the landscape and the development of habitats and dispersal...... Problemstellungen basieren auf multifunktionalen Nutzungskonzepten ruraler Landschaften, besonders im Hinblick auf Suburbanisierungsprozesse. Eine Anzahl untereinander vergleichbarer Projekte, mit parallelen bis ähnlichen Ausprägungen innerhalb Dänemarks und weiteerer europäischer Länder, werden exemplarisch...

  10. Navigating the Interface Between Landscape Genetics and Landscape Genomics

    Directory of Open Access Journals (Sweden)

    Andrew Storfer

    2018-03-01

    Full Text Available As next-generation sequencing data become increasingly available for non-model organisms, a shift has occurred in the focus of studies of the geographic distribution of genetic variation. Whereas landscape genetics studies primarily focus on testing the effects of landscape variables on gene flow and genetic population structure, landscape genomics studies focus on detecting candidate genes under selection that indicate possible local adaptation. Navigating the transition between landscape genomics and landscape genetics can be challenging. The number of molecular markers analyzed has shifted from what used to be a few dozen loci to thousands of loci and even full genomes. Although genome scale data can be separated into sets of neutral loci for analyses of gene flow and population structure and putative loci under selection for inference of local adaptation, there are inherent differences in the questions that are addressed in the two study frameworks. We discuss these differences and their implications for study design, marker choice and downstream analysis methods. Similar to the rapid proliferation of analysis methods in the early development of landscape genetics, new analytical methods for detection of selection in landscape genomics studies are burgeoning. We focus on genome scan methods for detection of selection, and in particular, outlier differentiation methods and genetic-environment association tests because they are the most widely used. Use of genome scan methods requires an understanding of the potential mismatches between the biology of a species and assumptions inherent in analytical methods used, which can lead to high false positive rates of detected loci under selection. Key to choosing appropriate genome scan methods is an understanding of the underlying demographic structure of study populations, and such data can be obtained using neutral loci from the generated genome-wide data or prior knowledge of a species

  11. Water, Forests, People: The Swedish Experience in Building Resilient Landscapes.

    Science.gov (United States)

    Eriksson, Mats; Samuelson, Lotta; Jägrud, Linnéa; Mattsson, Eskil; Celander, Thorsten; Malmer, Anders; Bengtsson, Klas; Johansson, Olof; Schaaf, Nicolai; Svending, Ola; Tengberg, Anna

    2018-05-21

    A growing world population and rapid expansion of cities increase the pressure on basic resources such as water, food and energy. To safeguard the provision of these resources, restoration and sustainable management of landscapes is pivotal, including sustainable forest and water management. Sustainable forest management includes forest conservation, restoration, forestry and agroforestry practices. Interlinkages between forests and water are fundamental to moderate water budgets, stabilize runoff, reduce erosion and improve biodiversity and water quality. Sweden has gained substantial experience in sustainable forest management in the past century. Through significant restoration efforts, a largely depleted Swedish forest has transformed into a well-managed production forest within a century, leading to sustainable economic growth through the provision of forest products. More recently, ecosystem services are also included in management decisions. Such a transformation depends on broad stakeholder dialog, combined with an enabling institutional and policy environment. Based on seminars and workshops with a wide range of key stakeholders managing Sweden's forests and waters, this article draws lessons from the history of forest management in Sweden. These lessons are particularly relevant for countries in the Global South that currently experience similar challenges in forest and landscape management. The authors argue that an integrated landscape approach involving a broad array of sectors and stakeholders is needed to achieve sustainable forest and water management. Sustainable landscape management-integrating water, agriculture and forests-is imperative to achieving resilient socio-economic systems and landscapes.

  12. Counter-Buffing: A Visual Criticism of Guerrilla Advertising

    Science.gov (United States)

    Lauzon, Robb Conrad; Cooke, Laquana

    2017-01-01

    This article addresses and explores hip-hop's reclamation of space using transit as a public bulletin. It is situated within counter-publics discourse and couched in the theoretical frameworks offered by visual rhetorical theory. This article also discusses hip-hop counter-publics through guerrilla advertising by former graffiti artists, SKI and…

  13. Urban Landscapes and Sustainable Cities

    Directory of Open Access Journals (Sweden)

    Erik Andersson

    2006-06-01

    Full Text Available Ecological research targeting sustainable urban landscapes needs to include findings and methods from many lines of ecological research, such as the link between biodiversity and ecosystem function, the role of humans in ecosystems, landscape connectivity, and resilience. This paper reviews and highlights the importance of these issues for sustainable use of ecosystem services, which is argued to be one aspect of sustainable cities. The paper stresses the need to include social and economic factors when analyzing urban landscapes. Spatially explicit data can be used to assess the roles different green areas have in providing people with ecosystem services, and whether people actually have access to the services. Such data can also be used to assess connectivity and heterogeneity, both argued to be central for continuous, long-term provision of these services, and to determine the role urban form has for sustainability.

  14. Legible landscapes: the use of narratives in landscape design for leisure and tourism in Dutch cultural landscapes.

    NARCIS (Netherlands)

    Brinkhuijsen, M.

    2007-01-01

    Nowadays, leisure and tourism have become significant factors in rural development, which is manifest in the ‘commodification’ of landscapes. However, leisure and tourist markets are very competitive and consumers increasingly demand high quality, unique and memorable experiences. Landscape

  15. Chapter 9. The landscape sector

    International Nuclear Information System (INIS)

    Larivaille, Pierrette

    1980-01-01

    The object of this work is to examine the interactions between the activities of the electric industry (generating, transmission and distribution) and the environment, whilst showing to what extent the facilities are likely to affect it adversely and describing the measures taken to lessen the detrimental effects. The chapter devoted to the 'landscape' includes a section covering the electricity generating facilities, and among these, the nuclear power stations. The studies carried out on the main units of insertion into the site are presented, particularly the landscaping involved in setting up a power station [fr

  16. Cooling towers in the landscape

    International Nuclear Information System (INIS)

    Boernke, F.

    1977-01-01

    The cooling tower as a large technical construction is one of the most original industrial buildings. It sticks out as an outlandish element in our building landscape, a giant which cannot be compared with the traditional forms of technical buildings. If it is constructed as a reinforced-concrete hyperboloid, its shape goes beyond all limits of building construction. Judgment of these highly individual constructions is only possible by applying a novel standard breaking completely with tradition. This new scale of height and dimension in industrial construction, and in particular the modern cooling tower, requires painstaking care and design and adaptation to the landscape around it. (orig.) [de

  17. Perfil da escolha alimentar de arroz e feijão na alimentação fora de casa em restaurante de bufê por peso Profile of the rice and beans food option when eating away from home at a buffet-by-weight restaurant

    Directory of Open Access Journals (Sweden)

    Alline Gouvea Martins Rodrigues

    2013-02-01

    Full Text Available Estudo transversal que descreve a prevalência e fatores associados à escolha de arroz e feijão (EAF entre comensais de um restaurante de bufê por peso. Coletou-se características antropométricas, sociodemográficas e comportamentais, o peso e a fotografia do prato escolhido. A amostra representativa foi composta por 675 comensais, entre 16-81 anos, e analisada uma subamostra de 396, composta por dois grupos: EAF e não EAF. O teste qui-quadrado examinou a representatividade da subamostra. Os testes de Wald, qui-quadrado e regressão de Poisson com variância robusta examinaram as associações entre EAF e as características coletadas. Observou-se ausência de EAF em 38,4% dos comensais. Após ajuste para as demais características, a ausência de EAF no prato associou-se diretamente com sobrepeso/obesidade (RR=1,43; IC95%=1,10-1,84, mulheres (1,57; 1,20-2,05, refeição não habitual (1,34; 1,02-1,75, escolhas de pastelaria (1,37; 1,06-1,76 e de acompanhamento frio (RR=1,39; IC95%=1,08-1,78; e, inversamente com prato de maior peso (0,54; 0,38-0,77. Conclui-se que a EAF ainda pode ser considerada habitual pelos brasileiros e mais frequente entre os homens. Sua não escolha parece estar associada a práticas alimentares menos saudáveis e risco aumentado de sobrepeso/obesidade.The scope of this cross-sectional study was to describe the prevalence and factors associated with the choice of rice and beans (CRB among diners in a buffet-by-weight restaurant. Data on anthropometric, socio-demographic and behavioral characteristics as well as weight and photographic record of the dishes chosen by the diner were collected. The representative sample consisted of 675 luncheon diners, aged between 16 and 81. A subsample of 396 diners was analyzed, consisted of two groups: CRB and non-CRB. The Chi-square test verified the representativeness of the subsample in relation to the total sample. The Wald test, the chi-square test and the Poisson regression

  18. Landscape history and archaeology of open field landscapes in Europe

    NARCIS (Netherlands)

    Renes, J.|info:eu-repo/dai/nl/071365303

    2016-01-01

    The landscapes of open fields were the grain baskets of medieval Europe. The term ‘open fields’ refers to the large arable fields that have an open character because the individual parcels of the owners were not surrounded by hedges, woodbanks, drystone walls or other visible boundaries. In this

  19. Competitive landscape for gas

    International Nuclear Information System (INIS)

    Newcomb, J.

    1990-01-01

    During the 1990s, natural gas will be the critical pressure point for energy and environmental developments in North America, according to the author of this paper. The author points to the forces bearing on natural gas, including the need for new power generation capacity, tightening environmental standards, growing concerns about energy security, cyclical factors in U.S. oil and gas exploration, and changes in the oil services industry. This paper discusses how these external factors will shape gas markets in the 1990s. First, it states that gas will gain market share in power generation through greater use of both existing gas-fired facilities and new turbines by electric utilities. Second, it predicts that the cumulative impact of the Clean Air Act and other environmental legislation having significant consequences for the relative roles of coal and natural gas, particularly during the late 1990s. Third, it points to the eventual reawakening of energy security concerns, focusing attention on developing North America's sizeable gas reserves. Finally, it states that while the long-term view of a gas supply crisis without a rebound in drilling activity is accurate, it has been disastrously wrong in the short term. This had led to underestimation of the amount of extra gas that can be provided in the interim from conventional areas at relatively low cost

  20. Measuring Thermal Characteristics of Urban Landscapes

    Science.gov (United States)

    Luvall, Jeffrey C.; Quattrochi, Dale A.; Rickman, Doug L.

    1999-01-01

    The additional heating of the air over the city is the result of the replacement of naturally vegetated surfaces with those composed of asphalt, concrete, rooftops and other man-made materials. The temperatures of these artificial surfaces can be 20 to 40 C higher than vegetated surfaces. Materials such as asphalt store much of the sun's energy and remains hot long after sunset. This produces a dome of elevated air temperatures 5 to 8 C greater over the city, compared to the air temperatures over adjacent rural areas. This effect is called the "urban heat island". Urban landscapes are a complex mixture of vegetated and nonvegetated surfaces. It is difficult to take enough temperature measurements over a large city area to characterize the complexity of urban radiant surface temperature variability. However, the use of remotely sensed thermal data from airborne scanners are ideal for the task. In a study funded by NASA, a series of flights over Huntsville, Alabama were performed in September 1994 and over Atlanta, Georgia in May 1997. Analysis of thermal energy responses for specific or discrete surfaces typical of the urban landscape (e.g., asphalt, building rooftops, vegetation) requires measurements at a very fine spatial scale (i.e., energy regimes. Additionally, very fine scale spatial resolution thermal infrared data, such as that obtained from aircraft, are very useful for demonstrating to planning officials, policy makers, and the general populace, what the benefits are of the urban forest in both mitigating the urban heat island effect, in making cities more aesthetically pleasing and more habitable environments, and in overall cooling of the community. In this presentation we will examine the techniques of analyzing remotely sensed data for measuring the effect of various urban surfaces on their contribution to the urban heat island effect.

  1. landscape incorporation in the environmental impact studies

    International Nuclear Information System (INIS)

    Gutierrez G, Luz Angela

    2000-01-01

    A general overview on landscape analysis showing the two principal approaches to their study, the article emphasize on the need of taking landscape in consideration on the making of the environmental impact study of any project of development

  2. Reading fitness landscape diagrams through HSAB concepts

    Energy Technology Data Exchange (ETDEWEB)

    Vigneresse, Jean-Louis, E-mail: jean-louis.vigneresse@univ-lorraine.fr

    2014-10-31

    Highlights: • Qualitative information from HSAB descriptors. • 2D–3D diagrams using chemical descriptors (χ, η, ω, α) and principles (MHP, mEP, mPP). • Estimate of the energy exchange during reaction paths. • Examples from complex systems (geochemistry). - Abstract: Fitness landscapes are conceived as range of mountains, with local peaks and valleys. In terms of potential, such topographic variations indicate places of local instability or stability. The chemical potential, or electronegativity, its value changed of sign, carries similar information. In addition to chemical descriptors defined through hard-soft acid-base (HSAB) concepts and computed through density functional theory (DFT), the principles that rule chemical reactions allow the design of such landscape diagrams. The simplest diagram uses electrophilicity and hardness as coordinates. It allows examining the influence of maximum hardness or minimum electrophilicity principles. A third dimension is introduced within such a diagram by mapping the topography of electronegativity, polarizability or charge exchange. Introducing charge exchange during chemical reactions, or mapping a third parameter (f.i. polarizability) reinforces the information carried by a simple binary diagram. Examples of such diagrams are provided, using data from Earth Sciences, simple oxides or ligands.

  3. Pedo-environmental evolution and agricultural landscape transformation

    Directory of Open Access Journals (Sweden)

    Gilmo Vianello

    Full Text Available Landscapes represent the stage setting of the ecosystem, the great theatre where the evolution of the environment, the changing of things and plant and animal life are played out; the diversity of landscapes derives from the combination, over time, of different environmental factors having perceptibly different roles, as in the case of climate, vegetation and human activity. Less perceptible and scarcely known is the role of soil, which has the ability not only to diversify the ecosystem’s landscapes but also to differentiate its level of productivity and liveability. The role of soil as part of the landscape is not always so evident, especially when it is covered by vegetation that precludes observation. At times, however, soils show themselves conspicuously, at least on the surface, when the colours of the epipedons invade the landscape and – in the ploughing season – dominate it. While it may be reassuring to see neatly cultivated fields and crops growing luxuriantly and homogeneously, the increasingly marked and evident signs of soil degradation or erosion are a cause for concern. In the recent past, the relationship between man and soil resources was strongly influenced by natural factors inside and outside the soil itself, socio-economic conditions and above all the labour force, i.e. the people employed in the primary sector; consequently, it was based on such factors that crop-growing choices were adapted to the different ecosystems, resulting in a diversification of rural landscapes. Starting from the second half of the twentieth century, the introduction of chemicals, mechanisation and exploitation of various forms of energy drastically transformed land use in the space of just a few years, with a logic aimed at improving the production capacity of farmland and forest land in both qualitative and quantitative terms. As a consequence, farming choices that were formerly adapted to the natural and socio-economic conditions of

  4. Pedo-environmental evolution and agricultural landscape transformation

    Directory of Open Access Journals (Sweden)

    Gilmo Vianello

    2009-10-01

    Full Text Available Landscapes represent the stage setting of the ecosystem, the great theatre where the evolution of the environment, the changing of things and plant and animal life are played out; the diversity of landscapes derives from the combination, over time, of different environmental factors having perceptibly different roles, as in the case of climate, vegetation and human activity. Less perceptible and scarcely known is the role of soil, which has the ability not only to diversify the ecosystem’s landscapes but also to differentiate its level of productivity and liveability. The role of soil as part of the landscape is not always so evident, especially when it is covered by vegetation that precludes observation. At times, however, soils show themselves conspicuously, at least on the surface, when the colours of the epipedons invade the landscape and – in the ploughing season – dominate it. While it may be reassuring to see neatly cultivated fields and crops growing luxuriantly and homogeneously, the increasingly marked and evident signs of soil degradation or erosion are a cause for concern. In the recent past, the relationship between man and soil resources was strongly influenced by natural factors inside and outside the soil itself, socio-economic conditions and above all the labour force, i.e. the people employed in the primary sector; consequently, it was based on such factors that crop-growing choices were adapted to the different ecosystems, resulting in a diversification of rural landscapes. Starting from the second half of the twentieth century, the introduction of chemicals, mechanisation and exploitation of various forms of energy drastically transformed land use in the space of just a few years, with a logic aimed at improving the production capacity of farmland and forest land in both qualitative and quantitative terms. As a consequence, farming choices that were formerly adapted to the natural and socio-economic conditions of

  5. THE METHODOLOGY OF VALORISING AND ASSESSING LANDSCAPE

    Directory of Open Access Journals (Sweden)

    Stanisław Jacek Bacior

    2017-01-01

    Full Text Available Landscape evaluation process requires access to particular information resources making it possible to regionalize (divide into zones the area under investigation. Thus, the starting point is landscape assessment and evaluation followed by regionalization. As a result of this step, we determine certain areas that are homogenous with regards to their landscape assets Keywords: assessing landscape, structure of rural areas, spatial planning of rural areas.

  6. Europe: the paradox of landscape change

    OpenAIRE

    Sluis, van der, Theo

    2017-01-01

    This thesis explores the processes of change in European rural landscapes. Landscapes have evolved over millennia as a result of human influence on the physical environment. Europe has a wide variety of landscapes that can alter within a relatively short distance, and which often form part of the national cultural identity of a European country. Central to this thesis, however, are insights into the processes of landscape change. In this context, the overall objective of this thesis is: To as...

  7. Flowers and Landscape by Serendipity.

    Science.gov (United States)

    Pippin, Sandi

    2003-01-01

    Describes an art lesson in which students sketch drawings of flowers and use watercolor paper and other materials to paint a landscape. Explains that the students also learn about impressionism in this lesson. Discusses how the students prepare the paper and create their artwork. (CMK)

  8. Landscape design methods in architecture

    NARCIS (Netherlands)

    Jauslin, D.T.

    2012-01-01

    Landscape has been used as a metaphor or conceptual reference for an increasing amount of excellent architectural projects in the last two decades. The phenomenon seems to be a substantial innovation of architecture with an interesting potential for artistic, social and ecological gains. To be able

  9. Biography of an Industrial Landscape

    DEFF Research Database (Denmark)

    Riesto, Svava

    Biography of an Industrial Landscape tells the story of one of the most significant urban redevelopment projects in northern Europe at the turn of the century. Examining the reinvention of the Carlsberg brewery site in Copenhagen as a city district, Svava Riesto unpacks the deeper assumptions abo...

  10. Eucalyptus as a landscape tree

    Science.gov (United States)

    W. Douglas Hamilton

    1983-01-01

    Ninety-two species of Eucalyptus were evaluated at the University of California re- search station in San Jose. The purpose: to find acceptable new street and park trees. Growth rates and horticultural characteristics were noted. Forty-three species were studied in locations statewide to evaluate site adaptation and landscape usefulness; flooded, cold, dry, saline....

  11. Dutch Architecture with Landscape Methods

    NARCIS (Netherlands)

    Abrami, F.; Bijster, J.; Bitarafan, N.; Cao, Z.; Cui, Y.; Liu, Y.; Ruan, L.; Maas, M.; Mayr, R.; Rozenmuller, M.; Toriano, L.; Yoshitake, M.; Jauslin, D.

    2009-01-01

    14 Project Documentations and Analysis of Dutch Architecture with Landscape Methods. MVRDV Villa VPRO, Powerhouse Company Villa 1, Herman Herzberger Coda Museum, NL Architects Basket Ba, SeARCH Posbank Pavillion, Wiel Arets Hedge House, OMA Kunsthal and Educatorium, Maaskant Johnson Wax, Diller &

  12. Language's Landscape of the Mind.

    Science.gov (United States)

    Tracy, Janet

    2000-01-01

    Describes how the author's 6 middle school students living in a village in the Yukon, 100 miles off the road system just below the arctic circle, enthusiastically wrote stories or poems about their lives. The students shared their works via an online electronic conferencing system with students from the unimaginably different landscape of the…

  13. Selected Landscape Plants. Slide Script.

    Science.gov (United States)

    McCann, Kevin

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with commercially important woody ornamental landscape plants. Included in the script are narrations for use with a total of 253 slides illustrating 92 different plants. Several slides are used to illustrate each plant: besides a view of…

  14. Ecological networks in urban landscapes

    NARCIS (Netherlands)

    Cook, E.A.

    2000-01-01

    This research focuses on the topic of ecological networks in urban landscapes. Analysis and planning of ecological networks is a relatively new phenomenon and is a response to fragmentation and deterioration of quality of natural systems. In agricultural areas and with existing nature

  15. Monarto’s Contested Landscape

    Directory of Open Access Journals (Sweden)

    Paul Walker

    2015-11-01

    Full Text Available The proposal to develop a new city at Monarto in South Australia during the 1970s was an important project of the reforming government of Don Dunstan. Dunstan’s view was that Monarto would be a city environmentally suited to the tough conditions of its site, and to an ‘Australian way of life’. As planning and preliminary design proceeded from 1972 to 1975, the landscape potential of the city’s selected site became central to its conception. This paper draws on new research comprising interviews with key participants and archival material to examine four issues: the adoption of an environmental orientation in Australian urban planning and discourse in the 1970s; strategies in the design proposals that seemingly gave Monarto validity even as the demographic and political drivers for it dissolved away; the investigations that supported Monarto’s landscape strategies; and attitudes to social and cultural history that the Monarto project adopted. While ultimately the plan for Monarto was abandoned, the projected city’s landscape can be seen as a theatre for competing values in relation to natural and cultural heritage and design ambitions. The paper situates Monarto within national and international urban discourse that is more complex than has been previously acknowledged, indicative of competing values and ideologies in the planning, landscape and design discourses of the period.

  16. Surface fluxes in heterogeneous landscape

    Energy Technology Data Exchange (ETDEWEB)

    Bay Hasager, C

    1997-01-01

    The surface fluxes in homogeneous landscapes are calculated by similarity scaling principles. The methodology is well establish. In heterogeneous landscapes with spatial changes in the micro scale range, i e from 100 m to 10 km, advective effects are significant. The present work focus on these effects in an agricultural countryside typical for the midlatitudes. Meteorological and satellite data from a highly heterogeneous landscape in the Rhine Valley, Germany was collected in the large-scale field experiment TRACT (Transport of pollutants over complex terrain) in 1992. Classified satellite images, Landsat TM and ERS SAR, are used as basis for roughness maps. The roughnesses were measured at meteorological masts in the various cover classes and assigned pixel by pixel to the images. The roughness maps are aggregated, i e spatially averaged, into so-called effective roughness lengths. This calculation is performed by a micro scale aggregation model. The model solves the linearized atmospheric flow equations by a numerical (Fast Fourier Transform) method. This model also calculate maps of friction velocity and momentum flux pixel wise in heterogeneous landscapes. It is indicated how the aggregation methodology can be used to calculate the heat fluxes based on the relevant satellite data i e temperature and soil moisture information. (au) 10 tabs., 49 ills., 223 refs.

  17. Space Strategies for the New Learning Landscape

    Science.gov (United States)

    Dugdale, Shirley

    2009-01-01

    The Learning Landscape is the total context for students' learning experiences and the diverse landscape of learning settings available today--from specialized to multipurpose, from formal to informal, and from physical to virtual. The goal of the Learning Landscape approach is to acknowledge this richness and maximize encounters among people,…

  18. Europe: the paradox of landscape change

    NARCIS (Netherlands)

    Sluis, van der Theo

    2017-01-01

    This thesis explores the processes of change in European rural landscapes. Landscapes have evolved over millennia as a result of human influence on the physical environment. Europe has a wide variety of landscapes that can alter within a relatively short distance, and which often form part of the

  19. Research needs for our national landscapes

    Science.gov (United States)

    Elwood L. Shafer

    1979-01-01

    The prevailing research problem for our national landscapes is: How shall we organize, control, and coordinate public and private development so as to protect, maintain, improve, and manage those landscape features that we value most? Research questions discussed include: environmental/political conflicts, taxation and zoning, landscape classification, public...

  20. Sustaining ecosystem services in cultural landscapes

    Directory of Open Access Journals (Sweden)

    Tobias Plieninger

    2014-06-01

    Full Text Available Classical conservation approaches focus on the man-made degradation of ecosystems and tend to neglect the social-ecological values that human land uses have imprinted on many environments. Throughout the world, ingenious land-use practices have generated unique cultural landscapes, but these are under pressure from agricultural intensification, land abandonment, and urbanization. In recent years, the cultural landscapes concept has been broadly adopted in science, policy, and management. The interest in both outstanding and vernacular landscapes finds expression in the UNESCO World Heritage Convention, the European Landscape Convention, and the IUCN Protected Landscape Approach. These policies promote the protection, management, planning, and governance of cultural landscapes. The ecosystem services approach is a powerful framework to guide such efforts, but has rarely been applied in landscape research and management. With this paper, we introduce a special feature that aims to enhance the theoretical, empirical and practical knowledge of how to safeguard the resilience of ecosystem services in cultural landscapes. It concludes (1 that the usefulness of the ecosystem services approach to the analysis and management of cultural landscapes should be reviewed more critically; (2 that conventional ecosystem services assessment needs to be complemented by socio-cultural valuation; (3 that cultural landscapes are inherently changing, so that a dynamic view on ecosystem services and a focus on drivers of landscape change are needed; and (4 that managing landscapes for ecosystem services provision may benefit from a social-ecological resilience perspective.

  1. Ecosystem services in changing landscapes: An introduction

    Science.gov (United States)

    Louis Iverson; Cristian Echeverria; Laura Nahuelhual; Sandra. Luque

    2014-01-01

    The concept of ecosystem services from landscapes is rapidly gaining momentum as a language to communicate values and benefits to scientists and lay alike. Landscape ecology has an enormous contribution to make to this field, and one could argue, uniquely so. Tools developed or adapted for landscape ecology are being increasingly used to assist with the quantification...

  2. Detectability of landscape effects on recolonization increases with regional population density.

    Science.gov (United States)

    Liman, Anna-Sara; Dalin, Peter; Björkman, Christer

    2015-07-01

    Variation in population size over time can influence our ability to identify landscape-moderated differences in community assembly. To date, however, most studies at the landscape scale only cover snapshots in time, thereby overlooking the temporal dynamics of populations and communities. In this paper, we present data that illustrate how temporal variation in population density at a regional scale can influence landscape-moderated variation in recolonization and population buildup in disturbed habitat patches. Four common insect species, two omnivores and two herbivores, were monitored over 8 years in 10 willow short-rotation coppice bio-energy stands with a four-year disturbance regime (coppice cycle). The population densities in these regularly disturbed stands were compared to densities in 17 undisturbed natural Salix cinerea (grey willow) stands in the same region. A time series approach was used, utilizing the natural variation between years to statistically model recolonization as a function of landscape composition under two different levels of regional density. Landscape composition, i.e. relative amount of forest vs. open agricultural habitats, largely determined the density of re-colonizing populations following willow coppicing in three of the four species. However, the impact of landscape composition was not detectable in years with low regional density. Our results illustrate that landscape-moderated recolonization can change over time and that considering the temporal dynamics of populations may be crucial when designing and evaluating studies at landscape level.

  3. URBAN LANDSCAPE QUALITY AND FACTORS THAT HAVE INFLUENCE ON LANDSCAPE QUALITY IN LATGALE REGION

    OpenAIRE

    Matisovs, Ivars

    2005-01-01

    The paper deals with urban landscape individualities in the cities and towns of Latgale region. Also show facilities and methods of integrated assessment of urban landscape quality. Article provides information about specifics of urban landscape and factors, that have influence on landscape quality. The paper presents the results of Daugavpils and Rēzekne urban landscape quality complex assessment, that have been realised in 2003- 2005. This results don’t establish significant disparities bet...

  4. Landscape Environmental Assessment Framework

    Energy Technology Data Exchange (ETDEWEB)

    2017-07-20

    LEAF Version 2.0 is a framework comprising of three models RUSLE2, WEPS, and AGNPS. The framework can predict row crop, crop residue, and energy crop yields at a sub-field resolutions for various combinations of soil, climate and crop management and residue harvesting practices. It estimates the loss of soil, carbon, and nutrients to the atmosphere, to the groundwater, and to runoff. It also models the overland flow of water and washed-off sediments, nutrients and other chemicals to provide estimates of sediment, nutrient, and chemical loadings to water bodies within a watershed. AGNPS model and wash-off calculations are the new additions to this version of LEAF. Development of LEAF software is supported by DOE's BETO program.

  5. Nuclear waste landscapes

    International Nuclear Information System (INIS)

    Solomon, B.D.; Cameron, D.M.

    1990-01-01

    In this paper the authors explore the time dimension in nuclear waste disposal, with the hope of untangling future land use issues for a full range of radioactive waste facilities. The longevity and hazards presented by nuclear reactor irradiated (spent) fuel and liquid reprocessing waste are well known. Final repositories for these highly radioactive wastes, to be opened early in the 21st Century, are to be located deep underground in rural locations throughout the developed world. Safety concerns are addressed by engineered and geological barriers containing the waste containers, as well as through geographic isolation from heavily populated areas. Yet nuclear power plants (as well as other applications of atomic energy) produce an abundance of other types of radioactive wastes. These materials are generally known as low level wastes (LLW) in the United States, though their level of longevity and radioactivity can vary dramatically

  6. The scale of inflation in the landscape

    Energy Technology Data Exchange (ETDEWEB)

    Pedro, F.G.; Westphal, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group

    2013-03-15

    We determine the frequency of regions of small-field inflation in the Wigner landscape as an approximation to random supergravities/type IIB flux compactifications. We show that small-field inflation occurs exponentially more often than large-field inflation The power of primordial gravitational waves from inflation is generically tied to the scale of inflation. For small-field models this is below observational reach. However, we find small-field inflation to be dominated by the highest inflationary energy scales compatible with a sub-Planckian field range. Hence, we expect a typical tensor-to-scalar ratio r{proportional_to}O(10{sup -3}) currently undetectable in upcoming CMB measurements.

  7. Landscapes of the Kruger National Park

    Directory of Open Access Journals (Sweden)

    W. P. D Gertenbach

    1983-12-01

    Full Text Available Knowledge on the abiotic and biotic components of the Kruger National Park (KNP system has increased to such an extent, that it was possible to zonate the KNP into landscapes. A landscape was defined as an area with a specific geomorphology, climate, soil and vegetation pattern together with the associated fauna. On this basis 35 landscapes were identified and described in terms of the components mentioned in the definition. The objective of classification is that future management should be based on these landscapes. Relevant management considerations may change, but the landscape a@ a basic functional unit should not be negotiable.

  8. Measuring Thermal Characteristics of Urban Landscapes

    Science.gov (United States)

    Luvall, Jeffrey C.; Quattrochi, Dale A.; Rickman, Doug L.

    1999-01-01

    The additional heating of the air over the city is the result of the replacement of naturally vegetated surfaces with those composed of asphalt, concrete, rooftops and other man-made materials. The temperatures of these artificial surfaces can be 20 to 40 C higher than vegetated surfaces. Materials such as asphalt store much of the sun's energy and remains hot long after sunset. This produces a dome of elevated air temperatures 5 to 8 C greater over the city, compared to the air temperatures over adjacent rural areas. This effect is called the "urban heat island". Urban landscapes are a complex mixture of vegetated and nonvegetated surfaces. It is difficult to take enough temperature measurements over a large city area to characterize the complexity of urban radiant surface temperature variability. However, the use of remotely sensed thermal data from airborne scanners are ideal for the task. In a study funded by NASA, a series of flights over Huntsville, Alabama were performed in September 1994 and over Atlanta, Georgia in May 1997. Analysis of thermal energy responses for specific or discrete surfaces typical of the urban landscape (e.g., asphalt, building rooftops, vegetation) requires measurements at a very fine spatial scale (i.e., urban forest in both mitigating the urban heat island effect, in making cities more aesthetically pleasing and more habitable environments, and in overall cooling of the community. In this presentation we will examine the techniques of analyzing remotely sensed data for measuring the effect of various urban surfaces on their contribution to the urban heat island effect.

  9. Purification effects of five landscape plants on river landscape water

    Science.gov (United States)

    Ling, Sun; Lei, Zheng; Mao, Qinqing; Ji, Qingxin

    2017-12-01

    Five species of landscape plants which are scindapsus aureus, water hyacinth, cockscomb, calendula officinalis and salvia splendens were used as experimental materials to study their removal effects on nitrogen, phosphorus, chemical oxygen demand (CODMn) and suspended solids (SS) in urban river water. The results show that the 5 landscape plants have good adaptability and vitality in water body, among them, water hyacinth had the best life signs than the other 4 plants, and its plant height and root length increased significantly. They have certain removal effects on the nitrogen, phosphorus, CODMn (Chemical Oxygen Demand) and SS (Suspended Substance) in the landscape water of Dalong Lake, Xuzhou. Scindapsus aureus, water hyacinth, cockscomb, calendula officinalis and salvia splendens on the removal rate of total nitrogen were 76.69%, 78.57%, 71.42%, 69.64%, 67.86%; the ammonia nitrogen removal rate were 71.06%, 74.28%, 67.85%, 63.02%, 59.81%;the total phosphorus removal rate were 78.70%, 81.48%, 73.15%, 72.22%, 68.52%;the orthophosphate removal rates were 78.37%, 80.77%, 75.96%, 75.96%, 71.15%;the removal rate of CODMn was 52.5%, 55.35%, 46.02%, 45.42%, 44.19%; the removal rate of SS was 81.4%, 86%, 79.1%, 76.7%, 74.42%.The purification effect of 5 kinds of landscape plants of Dalong Lake in Xuzhou City: water hyacinth> scindapsus aureus>cockscomb>calendula officinalis>salvia splendens.

  10. Assessment of landscape diversity and determination of landscape hotspots - a case of Slovenia

    Science.gov (United States)

    Perko, Drago; Ciglič, Rok; Hrvatin, Mauro

    2017-04-01

    Areas with high landscape diversity can be regarded as landscape hotspots, and vice versa areas with low landscape diversity can be marked as landscape coldspots. The main purpose of this paper is to use quantitative geoinformatical approach and identify parts of our test area (the country of Slovenia) that can be described as very diverse according to natural landscapes and natural elements. We used different digital raster data of natural elements and landscape classifications and defined landscape diversity and landscape hotspots. We defined diversity for each raster pixel by counting the number of different unique types of landscape elements and types of landscapes in its neighborhood. Namely, the method was used separately to define diversity according to natural elements (types of relief forms, rocks, and vegetation) and diversity according to existing geographical landscape classifications of Slovenia (types of landscapes). In both cases one-tenth of Slovenia's surface with the highest landscape diversity was defined as landscape hotspots. The same applies to the coldspots. Additionally we tested the same method of counting different types of landscapes in certain radius also for the area of Europe in order to find areas that are more diverse at continental level. By doing so we were able to find areas that have similar level of diversity as Slovenia according to different European landscape classifications. Areas with landscape diversity may have an advantage in economic development, especially in tourism. Such areas are also important for biodiversity, habitat, and species diversity. On the other hand, localities where various natural influences mix can also be areas where it is hard to transfer best practices from one place to another because of the varying responses of the landscapes to human intervention. Thus it is important to know where areas with high landscape diversity are.

  11. Legislative Framework for Landscape Planning in Latvia

    Science.gov (United States)

    Nitavska, Natalija; Zigmunde, Daiga

    2017-10-01

    With the adoption and the ratification of the European Landscape Convention a legally justified need for a clear landscape policy was grounded in the European countries. It includes the elaboration of the new and the improvement of the existing legislative documents on landscape planning, protection and management. The aim of the particular study is to analyse the existing legislative documents in Latvia influencing landscape planning on different scales / and the implementation of the European Landscape Convention. The study emphasizes the complex structure of the Latvian legislative framework affected by the distribution of the normative documents under the various ministries. Therefore, the main problem is unclear responsibility levels and organizational system for solving the issues regarding landscape planning, protection and management. Thus the various discussions between the involved disciplines and responsible institutions are arising. Two groups of the legislative documents influencing the implementation of the landscape policy in Latvia are detected within the study. The first group is strategic documents determining main landscape planning principles and directions at European, national, regional and professional or sectoral level. The second group is operational documents providing a set of actions for the landscape planning, protection and management at the local or the municipality level. The study concludes that operational documents developed by the municipalities are in high importance because of their direct influence on the landscape planning in Latvia. This often leads to the different landscape planning requirements included in the normative documents of the neighbouring municipalities, although the spatial and ecological borders of the visual landscape do not fit with the formal borders of the municipalities. Thus, it is essential to develop the common principles and actions that would be incumbent on all municipalities to provide the

  12. Astronomy Landscape in Africa

    Science.gov (United States)

    Nemaungani, Takalani

    2015-01-01

    The vision for astronomy in Africa is embedded in the African Space Policy of the African Union in early 2014. The vision is about positioning Africa as an emerging hub for astronomy sciences and facilities. Africa recognized the need to take advantage of its natural resource, the geographical advantage of the clear southern skies and pristine sites for astronomy. The Pan African University (PAU) initiative also presents an opportunity as a post-graduate training and research network of university nodes in five regions of Africa and supported by the African Union. The Southern African node based in South Africa concentrates on space sciences which also includes astronomy. The PAU aims to provide the opportunity for advanced graduate training and postgraduate research to high-performing African students. Objectives also include promoting mobility of students and teachers and harmonizing programs and degrees.A number of astronomy initiatives have burgeoned in the Southern African region and these include the Southern Africa Largest Optical Telescope (SALT), HESS (High Energy Stereoscopic System), the SKA (Square Kilometre Array) and the AVN (African Very Long Baseline Interferometer Network). There is a growing appetite for astronomy sciences in Africa. In East Africa, the astronomy community is well organized and is growing - the East African Astronomical society (EAAS) held its successful fourth annual conference since 2010 on 30 June to 04 July 2014 at the University of Rwanda. Centred around the 'Role of Astronomy in Socio-Economic Transformation,' this conference aimed at strengthening capacity building in Astronomy, Astrophysics and Space Science in general, while providing a forum for astronomers from the region to train young and upcoming scientists.

  13. Inflation in random Gaussian landscapes

    Energy Technology Data Exchange (ETDEWEB)

    Masoumi, Ali; Vilenkin, Alexander; Yamada, Masaki, E-mail: ali@cosmos.phy.tufts.edu, E-mail: vilenkin@cosmos.phy.tufts.edu, E-mail: Masaki.Yamada@tufts.edu [Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States)

    2017-05-01

    We develop analytic and numerical techniques for studying the statistics of slow-roll inflation in random Gaussian landscapes. As an illustration of these techniques, we analyze small-field inflation in a one-dimensional landscape. We calculate the probability distributions for the maximal number of e-folds and for the spectral index of density fluctuations n {sub s} and its running α {sub s} . These distributions have a universal form, insensitive to the correlation function of the Gaussian ensemble. We outline possible extensions of our methods to a large number of fields and to models of large-field inflation. These methods do not suffer from potential inconsistencies inherent in the Brownian motion technique, which has been used in most of the earlier treatments.

  14. Magical Landscapes and Designed Cities

    DEFF Research Database (Denmark)

    Raahauge, Kirsten Marie

    2008-01-01

    with “something special,” a feel-good, (almost spiritual) healing power (just moments away from the bustling city). In Melanesia, such a spiritual force goes by the name of “mana”. Århus’ mana landscapes are only invested with this huge, floating quality because they are near the city. Furthermore, they are seen...... from the point of view of the city, where order, design, planning and commerce are important cityscape qualities. The article deals with the way in which these two parts of the city, landscape and brandscape are complementary parts of the city-web. Analytical points made by Mauss, Lévi......-Strauss and Greimas are discussed in connection with the empirical setting of the city of Århus...

  15. A landscape of field theories

    Energy Technology Data Exchange (ETDEWEB)

    Maxfield, Travis [Enrico Fermi Institute, University of Chicago,Chicago, IL 60637 (United States); Robbins, Daniel [George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy,Texas A& M University,College Station, TX 77843-4242 (United States); Sethi, Savdeep [Enrico Fermi Institute, University of Chicago,Chicago, IL 60637 (United States)

    2016-11-28

    Studying a quantum field theory involves a choice of space-time manifold and a choice of background for any global symmetries of the theory. We argue that many more choices are possible when specifying the background. In the context of branes in string theory, the additional data corresponds to a choice of supergravity tensor fluxes. We propose the existence of a landscape of field theory backgrounds, characterized by the space-time metric, global symmetry background and a choice of tensor fluxes. As evidence for this landscape, we study the supersymmetric six-dimensional (2,0) theory compactified to two dimensions. Different choices of metric and flux give rise to distinct two-dimensional theories, which can preserve differing amounts of supersymmetry.

  16. Machine learning landscapes and predictions for patient outcomes

    Science.gov (United States)

    Das, Ritankar; Wales, David J.

    2017-07-01

    The theory and computational tools developed to interpret and explore energy landscapes in molecular science are applied to the landscapes defined by local minima for neural networks. These machine learning landscapes correspond to fits of training data, where the inputs are vital signs and laboratory measurements for a database of patients, and the objective is to predict a clinical outcome. In this contribution, we test the predictions obtained by fitting to single measurements, and then to combinations of between 2 and 10 different patient medical data items. The effect of including measurements over different time intervals from the 48 h period in question is analysed, and the most recent values are found to be the most important. We also compare results obtained for neural networks as a function of the number of hidden nodes, and for different values of a regularization parameter. The predictions are compared with an alternative convex fitting function, and a strong correlation is observed. The dependence of these results on the patients randomly selected for training and testing decreases systematically with the size of the database available. The machine learning landscapes defined by neural network fits in this investigation have single-funnel character, which probably explains why it is relatively straightforward to obtain the global minimum solution, or a fit that behaves similarly to this optimal parameterization.

  17. Biodiversity conservation in agricultural landscapes

    OpenAIRE

    Josefsson, Jonas

    2015-01-01

    Agricultural industrialization alters rural landscapes in Europe, causing large-scale and rapid loss of important biodiversity. The principal instruments to protect farmland biodiversity are various agri-environmental measures (AEMs) in the EU Common Agricultural Policy (CAP). However, growing awareness of shortcomings to CAP biodiversity integration prompts examination of causes and potential solutions. This thesis assesses the importance of structural heterogeneity of crop and non-crop habi...

  18. State Transitions in Semiarid Landscapes

    Science.gov (United States)

    Phillips, J. D.

    2012-04-01

    The U.S. Department of Agriculture has developed a large number of state-and-transition models (STM) to predict and interpret changes in vegetation communities in drylands of the southwestern U.S. These are represented as box-and-arrow models indicating potential changes in response to various combinations of management practices and environmental forcings. Analysis of the 320 STMs developed for areas within the state of Texas reveals two important aspects of environmental change in semiarid environments. First, the STMs are highly local—they are specific to very particular combinations of landform, soil, and climate. This is consistent with the perfect landscape concept in geomorphology, which emphasizes the irreducible importance of geographically and historically contingent local factors in addition to universal laws or principles in determining the state or condition of landscapes. Second, analysis of the STMs using algebraic graph theory shows that a majority of them have structures that tend to amplify effects of change and disturbances. In many cases the STMs represent a form of self-organization characterized by the potential of divergent behavior rather than convergence toward a dominant pattern or outcome. These results indicate that geomorphic, hydrologic, and ecological responses to climate and land use change are likely to be highly variable and idiosyncratic, both within and between semiarid landscapes of Texas.

  19. Vacuum selection on axionic landscapes

    International Nuclear Information System (INIS)

    Wang, Gaoyuan; Battefeld, Thorsten

    2016-01-01

    We compute the distribution of minima that are reached dynamically on multi-field axionic landscapes, both numerically and analytically. Such landscapes are well suited for inflationary model building due to the presence of shift symmetries and possible alignment effects (the KNP mechanism). The resulting distribution of dynamically reached minima differs considerably from the naive expectation based on counting all vacua. These differences are more pronounced in the presence of many fields due to dynamical selection effects: while low lying minima are preferred as fields roll down the potential, trajectories are also more likely to get trapped by one of the many nearby minima. We show that common analytic arguments based on random matrix theory in the large D-limit to estimate the distribution of minima are insufficient for quantitative arguments pertaining to the dynamically reached ones. This discrepancy is not restricted to axionic potentials. We provide an empirical expression for the expectation value of such dynamically reached minimas' height and argue that the cosmological constant problem is not alleviated in the absence of anthropic arguments. We further comment on the likelihood of inflation on axionic landscapes in the large D-limit

  20. Implementing Forest Landscape Restorationin Ethiopia

    Directory of Open Access Journals (Sweden)

    Till Pistorius

    2017-02-01

    Full Text Available Driven by various initiatives and international policy processes, the concept of Forest Landscape Restoration, is globally receiving renewed attention. It is seen internationally and in national contexts as a means for improving resilience of land and communities in the face of increasing environmental degradation through different forest activities. Ethiopia has made a strong voluntary commitment in the context of the Bonn Challenge—it seeks to implement Forest Landscape Restoration (FLR on 15 million ha. In the context of rural Ethiopia, forest establishment and restoration provide a promising approach to reverse the widespread land degradation, which is exacerbated by climate change and food insecurity. This paper presents an empirical case study of FLR opportunities in the Amhara National Regional State, Ethiopia’s largest spans of degraded and barren lands. Following the Restoration Opportunity Assessment Methodology, the study categorizes the main types of landscapes requiring restoration, identifies and prioritizes respective FLR options, and details the costs and benefits associated with each of the five most significant opportunities: medium to large‐scale afforestation and reforestation activities on deforested or degraded marginal land not suitable for agriculture, the introduction of participatory forest management, sustainable woodland management combined with value chain investments, restoration of afro‐alpine and sub‐afro‐alpine areas and the establishment of woodlots.