WorldWideScience

Sample records for extremely complex nature

  1. Extremes in nature

    CERN Document Server

    Salvadori, Gianfausto; Kottegoda, Nathabandu T

    2007-01-01

    This book is about the theoretical and practical aspects of the statistics of Extreme Events in Nature. Most importantly, this is the first text in which Copulas are introduced and used in Geophysics. Several topics are fully original, and show how standard models and calculations can be improved by exploiting the opportunities offered by Copulas. In addition, new quantities useful for design and risk assessment are introduced.

  2. Distributions of extreme bursts above thresholds in a fractional Lévy toy model of natural complexity.

    Science.gov (United States)

    Watkins, Nicholas; Chapman, Sandra; Rosenberg, Sam; Credgington, Dan; Sanchez, Raul

    2010-05-01

    In 2 far-sighted contributions in the 1960s Mandelbrot showed the ubiquity of both non-Gaussian fluctuations and long-ranged temporal memory (the "Noah" and "Joseph" effects, respectively) in the natural and man-made worlds. Much subsequent work in complexity science has contributed to the physical underpinning of these effects, particularly in cases where complex interactions in a system cause a driven or random perturbation to be nonlinearly amplified in amplitude and/or spread out over a wide range of frequencies. In addition the modelling of catastrophes has begun to incorporate the insights which these approaches have offered into the likelihood of extreme and long-lived fluctuations. I will briefly survey how the application of the above ideas in the earth system has been a key focus and motivation of research into natural complexity at BAS [e.g. Watkins & Freeman, Science, 2008; Edwards et al, Nature, 2007]. I will then discuss in detail a standard toy model (linear fractional stable motion, LFSM) which combines the Noah and Joseph effects in a controllable way and explain how it differs from the widely used continuous time random walk. I will describe how LFSM is being used to explore the interplay of the above two effects in the distribution of bursts above thresholds. I will describe ongoing work to improve the accuracy of maximum likelihood-based estimation of burst size and waiting time distributions for LFSM first reported in [Watkins et al, PRE, 2009]; and will also touch on similar work for multifractal models [Watkins et al, PRL comment, 2009].

  3. Extreme Events in Nature and Society

    CERN Document Server

    Albeverio, Sergio; Kantz, Holger

    2006-01-01

    Significant, and usually unwelcome, surprises, such as floods, financial crisis, epileptic seizures, or material rupture, are the topics of Extreme Events in Nature and Society. The book, authored by foremost experts in these fields, reveals unifying and distinguishing features of extreme events, including problems of understanding and modelling their origin, spatial and temporal extension, and potential impact. The chapters converge towards the difficult problem of anticipation: forecasting the event and proposing measures to moderate or prevent it. Extreme Events in Nature and Society will interest not only specialists, but also the general reader eager to learn how the multifaceted field of extreme events can be viewed as a coherent whole.

  4. Controlling extreme events on complex networks

    Science.gov (United States)

    Chen, Yu-Zhong; Huang, Zi-Gang; Lai, Ying-Cheng

    2014-08-01

    Extreme events, a type of collective behavior in complex networked dynamical systems, often can have catastrophic consequences. To develop effective strategies to control extreme events is of fundamental importance and practical interest. Utilizing transportation dynamics on complex networks as a prototypical setting, we find that making the network ``mobile'' can effectively suppress extreme events. A striking, resonance-like phenomenon is uncovered, where an optimal degree of mobility exists for which the probability of extreme events is minimized. We derive an analytic theory to understand the mechanism of control at a detailed and quantitative level, and validate the theory numerically. Implications of our finding to current areas such as cybersecurity are discussed.

  5. Complex Plasma Research Under Extreme Conditions

    International Nuclear Information System (INIS)

    Ishihara, Osamu

    2008-01-01

    Complex plasma research under extreme conditions is described. The extreme conditions include low-dimensionality for self-organized structures of dust particles, dust magnetization in high magnetic field, criticality in phase transition, and cryogenic environment for Coulomb crystals and dust dynamics.

  6. Disaster Risks Reduction for Extreme Natural Hazards

    Science.gov (United States)

    Plag, H.; Jules-Plag, S.

    2013-12-01

    Mega disasters associated with extreme natural hazards have the potential to escalate the global sustainability crisis and put us close to the boundaries of the safe operating space for humanity. Floods and droughts are major threats that potentially could reach planetary extent, particularly through secondary economic and social impacts. Earthquakes and tsunamis frequently cause disasters that eventually could exceed the immediate coping capacity of the global economy, particularly since we have built mega cities in hazardous areas that are now ready to be harvested by natural hazards. Unfortunately, the more we learn to cope with the relatively frequent hazards (50 to 100 years events), the less we are worried about the low-probability, high-impact events (a few hundred and more years events). As a consequence, threats from the 500 years flood, drought, volcano eruption are not appropriately accounted for in disaster risk reduction (DRR) discussions. Extreme geohazards have occurred regularly throughout the past, but mostly did not cause major disasters because exposure of human assets to hazards was much lower in the past. The most extreme events that occurred during the last 2,000 years would today cause unparalleled damage on a global scale and could worsen the sustainability crisis. Simulation of these extreme hazards under present conditions can help to assess the disaster risk. Recent extreme earthquakes have illustrated the destruction they can inflict, both directly and indirectly through tsunamis. Large volcano eruptions have the potential to impact climate, anthropogenic infrastructure and resource supplies on global scale. During the last 2,000 years several large volcano eruptions occurred, which under today's conditions are associated with extreme disaster risk. The comparison of earthquakes and volcano eruptions indicates that large volcano eruptions are the low-probability geohazards with potentially the highest impact on our civilization

  7. Nature, computation and complexity

    International Nuclear Information System (INIS)

    Binder, P-M; Ellis, G F R

    2016-01-01

    The issue of whether the unfolding of events in the world can be considered a computation is explored in this paper. We come to different conclusions for inert and for living systems (‘no’ and ‘qualified yes’, respectively). We suggest that physical computation as we know it exists only as a tool of complex biological systems: us. (paper)

  8. Managing extreme natural disasters in coastal areas

    Science.gov (United States)

    Kesavan, P. C.; Swaminathan, M. S.

    2006-08-01

    Extreme natural hazards, particularly the hydro-meteorological disasters, are emerging as a cause of major concern in the coastal regions of India and a few other developing countries. These have become more frequent in the recent past, and are taking a heavy toll of life and livelihoods. Low level of technology development in the rural areas together with social, economic and gender inequities enhance the vulnerability of the largely illiterate, unskilled, and resource-poor fishing, farming and landless labour communities. Their resilience to bounce back to pre-disaster level of normality is highly limited. For the planet Earth at crossroads, the imminent threat, however, is from a vicious spiral among environmental degradation, poverty and climate change-related natural disasters interacting in a mutually reinforcing manner. These, in turn, retard sustainable development, and also wipe out any small gains made thereof. To counter this unacceptable trend, the M.S. Swaminathan Research Foundation has developed a biovillage paradigm and rural knowledge centres for ecotechnological and knowledge empowerment of the coastal communities at risk. Frontier science and technologies blended with traditional knowledge and ecological prudence result in ecotechnologies with pro-nature, pro-poor and pro-women orientation. The rural communities are given training and helped to develop capacity to adopt ecotechnologies for market-driven eco-enterprises. The modern information and communication-based rural knowledge centres largely operated by trained semi-literate young women provide time- and locale-specific information on weather, crop and animal husbandry, market trends and prices for local communities, healthcare, transport, education, etc. to the local communities. The ecotechnologies and time- and locale-specific information content development are need-based and chosen in a ‘bottom-up’ manner. The use of recombinant DNA technology for genetic shielding of agricultural

  9. Magnetars: Challenging the Extremes of Nature

    Science.gov (United States)

    Kouveliotou, Chryssa

    2011-01-01

    Magnetars are magnetically powered rotating neutron stars with extreme magnetic fields (over 10(exp 14) Gauss). They are discovered and emit predominantly in the X- and gamma-rays. Very few sources (roughly 15) have been found since their discovery in 1987. NASA s Fermi Observatory was launched June 11, 2009; the Fermi Gamma Ray Burst Monitor (GBM) began normal operations on July 14, about a month after launch, when the trigger algorithms were enabled. Since then, we recorded emission from four magnetar sources; of these, only one was an old magnetar: SGR 1806+20. The other three detections were two brand new sources, SGR J0501+4516, discovered with Swift and extensively monitored with both Swift and GBM, SGR J0418+5729, discovered with GBM and the Interplanetary Network (IPN), and SGR J1550-5418, a source originally classified as an Anomalous X-ray Pulsar (AXP 1E1547.0-5408). In my talk I will give a short history of the discovery of magnetars and describe how this, once relatively esoteric field, has emerged as a link between several astrophysical areas including Gamma-Ray Bursts. Finally, I will describe the properties of these sources and the current status of our knowledge of the magnetar population and birth rate.

  10. Complexity in Individual Trajectories toward Online Extremism

    Directory of Open Access Journals (Sweden)

    Z. Cao

    2018-01-01

    Full Text Available Society faces a fundamental global problem of understanding which individuals are currently developing strong support for some extremist entity such as ISIS (Islamic State, even if they never end up doing anything in the real world. The importance of online connectivity in developing intent has been confirmed by recent case studies of already convicted terrorists. Here we use ideas from Complexity to identify dynamical patterns in the online trajectories that individuals take toward developing a high level of extremist support, specifically, for ISIS. Strong memory effects emerge among individuals whose transition is fastest and hence may become “out of the blue” threats in the real world. A generalization of diagrammatic expansion theory helps quantify these characteristics, including the impact of changes in geographical location, and can facilitate prediction of future risks. By quantifying the trajectories that individuals follow on their journey toward expressing high levels of pro-ISIS support—irrespective of whether they then carry out a real-world attack or not—our findings can help move safety debates beyond reliance on static watch-list identifiers such as ethnic background or immigration status and/or postfact interviews with already convicted individuals. Given the broad commonality of social media platforms, our results likely apply quite generally; for example, even on Telegram where (like Twitter there is no built-in group feature as in our study, individuals tend to collectively build and pass through the so-called super-group accounts.

  11. Predicting extreme rainfall over eastern Asia by using complex networks

    International Nuclear Information System (INIS)

    He Su-Hong; Gong Yan-Chun; Huang Yan-Hua; Wu Cheng-Guo; Feng Tai-Chen; Gong Zhi-Qiang

    2014-01-01

    A climate network of extreme rainfall over eastern Asia is constructed for the period of 1971–2000, employing the tools of complex networks and a measure of nonlinear correlation called event synchronization (ES). Using this network, we predict the extreme rainfall for several cases without delay and with n-day delay (1 ≤ n ≤ 10). The prediction accuracy can reach 58% without delay, 21% with 1-day delay, and 12% with n-day delay (2 ≤ n ≤ 10). The results reveal that the prediction accuracy is low in years of a weak east Asia summer monsoon (EASM) or 1 year later and high in years of a strong EASM or 1 year later. Furthermore, the prediction accuracy is higher due to the many more links that represent correlations between different grid points and a higher extreme rainfall rate during strong EASM years. (geophysics, astronomy, and astrophysics)

  12. Local likelihood estimation of complex tail dependence structures in high dimensions, applied to US precipitation extremes

    KAUST Repository

    Camilo, Daniela Castro

    2017-10-02

    In order to model the complex non-stationary dependence structure of precipitation extremes over the entire contiguous U.S., we propose a flexible local approach based on factor copula models. Our sub-asymptotic spatial modeling framework yields non-trivial tail dependence structures, with a weakening dependence strength as events become more extreme, a feature commonly observed with precipitation data but not accounted for in classical asymptotic extreme-value models. To estimate the local extremal behavior, we fit the proposed model in small regional neighborhoods to high threshold exceedances, under the assumption of local stationarity. This allows us to gain in flexibility, while making inference for such a large and complex dataset feasible. Adopting a local censored likelihood approach, inference is made on a fine spatial grid, and local estimation is performed taking advantage of distributed computing resources and of the embarrassingly parallel nature of this estimation procedure. The local model is efficiently fitted at all grid points, and uncertainty is measured using a block bootstrap procedure. An extensive simulation study shows that our approach is able to adequately capture complex, non-stationary dependencies, while our study of U.S. winter precipitation data reveals interesting differences in local tail structures over space, which has important implications on regional risk assessment of extreme precipitation events. A comparison between past and current data suggests that extremes in certain areas might be slightly wider in extent nowadays than during the first half of the twentieth century.

  13. Local likelihood estimation of complex tail dependence structures in high dimensions, applied to US precipitation extremes

    KAUST Repository

    Camilo, Daniela Castro; Huser, Raphaë l

    2017-01-01

    In order to model the complex non-stationary dependence structure of precipitation extremes over the entire contiguous U.S., we propose a flexible local approach based on factor copula models. Our sub-asymptotic spatial modeling framework yields non-trivial tail dependence structures, with a weakening dependence strength as events become more extreme, a feature commonly observed with precipitation data but not accounted for in classical asymptotic extreme-value models. To estimate the local extremal behavior, we fit the proposed model in small regional neighborhoods to high threshold exceedances, under the assumption of local stationarity. This allows us to gain in flexibility, while making inference for such a large and complex dataset feasible. Adopting a local censored likelihood approach, inference is made on a fine spatial grid, and local estimation is performed taking advantage of distributed computing resources and of the embarrassingly parallel nature of this estimation procedure. The local model is efficiently fitted at all grid points, and uncertainty is measured using a block bootstrap procedure. An extensive simulation study shows that our approach is able to adequately capture complex, non-stationary dependencies, while our study of U.S. winter precipitation data reveals interesting differences in local tail structures over space, which has important implications on regional risk assessment of extreme precipitation events. A comparison between past and current data suggests that extremes in certain areas might be slightly wider in extent nowadays than during the first half of the twentieth century.

  14. Study of Environmental Data Complexity using Extreme Learning Machine

    Science.gov (United States)

    Leuenberger, Michael; Kanevski, Mikhail

    2017-04-01

    The main goals of environmental data science using machine learning algorithm deal, in a broad sense, around the calibration, the prediction and the visualization of hidden relationship between input and output variables. In order to optimize the models and to understand the phenomenon under study, the characterization of the complexity (at different levels) should be taken into account. Therefore, the identification of the linear or non-linear behavior between input and output variables adds valuable information for the knowledge of the phenomenon complexity. The present research highlights and investigates the different issues that can occur when identifying the complexity (linear/non-linear) of environmental data using machine learning algorithm. In particular, the main attention is paid to the description of a self-consistent methodology for the use of Extreme Learning Machines (ELM, Huang et al., 2006), which recently gained a great popularity. By applying two ELM models (with linear and non-linear activation functions) and by comparing their efficiency, quantification of the linearity can be evaluated. The considered approach is accompanied by simulated and real high dimensional and multivariate data case studies. In conclusion, the current challenges and future development in complexity quantification using environmental data mining are discussed. References - Huang, G.-B., Zhu, Q.-Y., Siew, C.-K., 2006. Extreme learning machine: theory and applications. Neurocomputing 70 (1-3), 489-501. - Kanevski, M., Pozdnoukhov, A., Timonin, V., 2009. Machine Learning for Spatial Environmental Data. EPFL Press; Lausanne, Switzerland, p.392. - Leuenberger, M., Kanevski, M., 2015. Extreme Learning Machines for spatial environmental data. Computers and Geosciences 85, 64-73.

  15. Complexes of natural carbohydrates with metal cations

    International Nuclear Information System (INIS)

    Alekseev, Yurii E; Garnovskii, Alexander D; Zhdanov, Yu A

    1998-01-01

    Data on the interaction of natural carbohydrates (mono-, oligo-, and poly-saccharides, amino sugars, and natural organic acids of carbohydrate origin) with metal cations are surveyed and described systematically. The structural diversity of carbohydrate metal complexes, caused by some specific features of carbohydrates as ligands, is demonstrated. The influence of complex formation on the chemical properties of carbohydrates is discussed. It is shown that the formation of metal complexes plays an important role in the configurational and conformational analysis of carbohydrates. The practical significance of the coordination interaction in the series of carbohydrate ligands is demonstrated. The bibliography includes 571 references.

  16. Marine Extremes and Natural Hazards: when the key is variability.

    Science.gov (United States)

    Marone, Eduardo; Camargo, Ricardo; Salcedo Castro, Julio

    2014-05-01

    At EGU2013 we used the work we are conducting regarding marine extreme events and natural hazards to exploit the distance that separate the scientific community and the non academic society, trying to show where bridges need to be built an how an ethical behavior among the scientists needs to be in place to succeed. We concluded that our actions as scientists have not been the most appropriate in communicating outside the academy our results, particularly when our findings have to do with natural hazards which could contribute to loss of life and the environmental quality that sustains it. Even if one of the barriers that separate the academy from society is the "language", too cryptic even for a well educated (not scientific) citizen in many cases, we scientists complicated even more the problems when we stop worrying about some basic concepts regarding the scientific method once upon a time were teach at basic school levels, particularly concerning differences as accuracy and precision, or the concept of uncertainty and the errors which permeate any observation or scientific "prediction". Science teaching at basic levels was not lost, but changed in the XXth century, concentrating in the so many new advancements and abandoning classical but necessary learning processes just about how sciences is done and why. When studying marine extreme events, we use statistic, stochastic methods, deterministic analysis, logical and numerical modeling, etc. However, our results are still very far away of being accurate, while our precision, however is improving just a little, it is still far away of ideal. That appears to be somehow obvious if we look just the observed vs. the modeled data. Nevertheless, if we look not the absolute values of our results, but the "rhythm" of their variability and compare these cadences with the beats observed in nature, new patterns arose, and clues about how to act regarding natural hazards and extreme events became more clear. We are being

  17. Numerical Modelling of Extreme Natural Hazards in the Russian Seas

    Science.gov (United States)

    Arkhipkin, Victor; Dobrolyubov, Sergey; Korablina, Anastasia; Myslenkov, Stanislav; Surkova, Galina

    2017-04-01

    Storm surges and extreme waves are severe natural sea hazards. Due to the almost complete lack of natural observations of these phenomena in the Russian seas (Caspian, Black, Azov, Baltic, White, Barents, Okhotsk, Kara), especially about their formation, development and destruction, they have been studied using numerical simulation. To calculate the parameters of wind waves for the seas listed above, except the Barents Sea, the spectral model SWAN was applied. For the Barents and Kara seas we used WAVEWATCH III model. Formation and development of storm surges were studied using ADCIRC model. The input data for models - bottom topography, wind, atmospheric pressure and ice cover. In modeling of surges in the White and Barents seas tidal level fluctuations were used. They have been calculated from 16 harmonic constant obtained from global atlas tides FES2004. Wind, atmospheric pressure and ice cover was taken from the NCEP/NCAR reanalysis for the period from 1948 to 2010, and NCEP/CFSR reanalysis for the period from 1979 to 2015. In modeling we used both regular and unstructured grid. The wave climate of the Caspian, Black, Azov, Baltic and White seas was obtained. Also the extreme wave height possible once in 100 years has been calculated. The statistics of storm surges for the White, Barents and Azov Seas were evaluated. The contribution of wind and atmospheric pressure in the formation of surges was estimated. The technique of climatic forecast frequency of storm synoptic situations was developed and applied for every sea. The research was carried out with financial support of the RFBR (grant 16-08-00829).

  18. Naturally Efficient Emitters: Luminescent Organometallic Complexes Derived from Natural Products

    Science.gov (United States)

    Zhang, Wen-Hua; Young, David J.

    2013-08-01

    Naturally occurring molecules offer intricate structures and functionality that are the basis of modern medicinal chemistry, but are under-represented in materials science. Herein, we review recent literature describing the use of abundant and relatively inexpensive, natural products for the synthesis of ligands for luminescent organometallic complexes used for organic light emitting diodes (OLEDs) and related technologies. These ligands are prepared from the renewable starting materials caffeine, camphor, pinene and cinchonine and, with the exception of caffeine, impart performance improvements to the emissive metal complexes and resulting OLED devices, with emission wavelengths that span the visible spectrum from blue to red. The advantages of these biologically-derived molecules include improved solution processibility and phase homogeneity, brighter luminescence, higher quantum efficiencies and lower turn-on voltages. While nature has evolved these carbon-skeletons for specific purposes, they also offer some intriguing benefits in materials science and technology.

  19. Complexity, Modeling, and Natural Resource Management

    Directory of Open Access Journals (Sweden)

    Paul Cilliers

    2013-09-01

    Full Text Available This paper contends that natural resource management (NRM issues are, by their very nature, complex and that both scientists and managers in this broad field will benefit from a theoretical understanding of complex systems. It starts off by presenting the core features of a view of complexity that not only deals with the limits to our understanding, but also points toward a responsible and motivating position. Everything we do involves explicit or implicit modeling, and as we can never have comprehensive access to any complex system, we need to be aware both of what we leave out as we model and of the implications of the choice of our modeling framework. One vantage point is never sufficient, as complexity necessarily implies that multiple (independent conceptualizations are needed to engage the system adequately. We use two South African cases as examples of complex systems - restricting the case narratives mainly to the biophysical domain associated with NRM issues - that make the point that even the behavior of the biophysical subsystems themselves are already complex. From the insights into complex systems discussed in the first part of the paper and the lessons emerging from the way these cases have been dealt with in reality, we extract five interrelated generic principles for practicing science and management in complex NRM environments. These principles are then further elucidated using four further South African case studies - organized as two contrasting pairs - and now focusing on the more difficult organizational and social side, comparing the human organizational endeavors in managing such systems.

  20. Complex architecture of primes and natural numbers.

    Science.gov (United States)

    García-Pérez, Guillermo; Serrano, M Ángeles; Boguñá, Marián

    2014-08-01

    Natural numbers can be divided in two nonoverlapping infinite sets, primes and composites, with composites factorizing into primes. Despite their apparent simplicity, the elucidation of the architecture of natural numbers with primes as building blocks remains elusive. Here, we propose a new approach to decoding the architecture of natural numbers based on complex networks and stochastic processes theory. We introduce a parameter-free non-Markovian dynamical model that naturally generates random primes and their relation with composite numbers with remarkable accuracy. Our model satisfies the prime number theorem as an emerging property and a refined version of Cramér's conjecture about the statistics of gaps between consecutive primes that seems closer to reality than the original Cramér's version. Regarding composites, the model helps us to derive the prime factors counting function, giving the probability of distinct prime factors for any integer. Probabilistic models like ours can help to get deeper insights about primes and the complex architecture of natural numbers.

  1. Prediction of extreme floods in the Central Andes by means of Complex Networks

    Science.gov (United States)

    Boers, Niklas; Bookhagen, Bodo; Barbosa, Henrique; Marwan, Norbert; Kurths, Jürgen; Marengo, Jose

    2014-05-01

    Based on a non-linear synchronisation measure and complex network theory, we present a novel framework for the prediction of extreme events of spatially embedded, interrelated time series. This method is general in the sense that it can be applied to any type of spatially sampled time series with significant interrelations, ranging from climate observables to biological or stock market data. In this presentation, we apply our method to extreme rainfall in South America and show how this leads to the prediction of more than 60% (90% during El Niño conditions) of extreme rainfall events in the eastern Central Andes of Bolivia and northern Argentina, with only 1% false alarms. From paleoclimatic to decadal time scales, the Central Andes continue to be subject to pronounced changes in climatic conditions. In particular, our and past work shows that frequency as well as magnitudes of extreme rainfall events have increased significantly during past decades, calling for a better understanding of the involved climatic mechanisms. Due to their large spatial extend and occurrence at high elevations, these extreme events often lead to severe floods and landslides with disastrous socioeconomic impacts. They regularly affect tens of thousands of people and produce estimated costs of the order of several hundred million USD. Alongside with the societal value of predicting natural hazards, our study provides insights into the responsible climatic features and suggests interactions between Rossby waves in polar regions and large scale (sub-)tropical moisture transport as a driver of subseasonal variability of the South American monsoon system. Predictable extreme events result from the propagation of extreme rainfall from the region of Buenos Aires towards the Central Andes given characteristic atmospheric conditions. Our results indicate that the role of frontal systems originating from Rossby waves in polar latitudes is much more dominant for controlling extreme rainfall in

  2. The Future of Coral Reefs Subject to Rapid Climate Change: Lessons from Natural Extreme Environments

    Directory of Open Access Journals (Sweden)

    Emma F. Camp

    2018-02-01

    Full Text Available Global climate change and localized anthropogenic stressors are driving rapid declines in coral reef health. In vitro experiments have been fundamental in providing insight into how reef organisms will potentially respond to future climates. However, such experiments are inevitably limited in their ability to reproduce the complex interactions that govern reef systems. Studies examining coral communities that already persist under naturally-occurring extreme and marginal physicochemical conditions have therefore become increasingly popular to advance ecosystem scale predictions of future reef form and function, although no single site provides a perfect analog to future reefs. Here we review the current state of knowledge that exists on the distribution of corals in marginal and extreme environments, and geographic sites at the latitudinal extremes of reef growth, as well as a variety of shallow reef systems and reef-neighboring environments (including upwelling and CO2 vent sites. We also conduct a synthesis of the abiotic data that have been collected at these systems, to provide the first collective assessment on the range of extreme conditions under which corals currently persist. We use the review and data synthesis to increase our understanding of the biological and ecological mechanisms that facilitate survival and success under sub-optimal physicochemical conditions. This comprehensive assessment can begin to: (i highlight the extent of extreme abiotic scenarios under which corals can persist, (ii explore whether there are commonalities in coral taxa able to persist in such extremes, (iii provide evidence for key mechanisms required to support survival and/or persistence under sub-optimal environmental conditions, and (iv evaluate the potential of current sub-optimal coral environments to act as potential refugia under changing environmental conditions. Such a collective approach is critical to better understand the future survival of

  3. 454 sequencing reveals extreme complexity of the class II Major Histocompatibility Complex in the collared flycatcher

    Directory of Open Access Journals (Sweden)

    Gustafsson Lars

    2010-12-01

    Full Text Available Abstract Background Because of their functional significance, the Major Histocompatibility Complex (MHC class I and II genes have been the subject of continuous interest in the fields of ecology, evolution and conservation. In some vertebrate groups MHC consists of multiple loci with similar alleles; therefore, the multiple loci must be genotyped simultaneously. In such complex systems, understanding of the evolutionary patterns and their causes has been limited due to challenges posed by genotyping. Results Here we used 454 amplicon sequencing to characterize MHC class IIB exon 2 variation in the collared flycatcher, an important organism in evolutionary and immuno-ecological studies. On the basis of over 152,000 sequencing reads we identified 194 putative alleles in 237 individuals. We found an extreme complexity of the MHC class IIB in the collared flycatchers, with our estimates pointing to the presence of at least nine expressed loci and a large, though difficult to estimate precisely, number of pseudogene loci. Many similar alleles occurred in the pseudogenes indicating either a series of recent duplications or extensive concerted evolution. The expressed alleles showed unambiguous signals of historical selection and the occurrence of apparent interlocus exchange of alleles. Placing the collared flycatcher's MHC sequences in the context of passerine diversity revealed transspecific MHC class II evolution within the Muscicapidae family. Conclusions 454 amplicon sequencing is an effective tool for advancing our understanding of the MHC class II structure and evolutionary patterns in Passeriformes. We found a highly dynamic pattern of evolution of MHC class IIB genes with strong signals of selection and pronounced sequence divergence in expressed genes, in contrast to the apparent sequence homogenization in pseudogenes. We show that next generation sequencing offers a universal, affordable method for the characterization and, in perspective

  4. On Impact Dynamics under Complex or Extreme Conditions

    KAUST Repository

    Kouraytem, Nadia

    2016-11-01

    The impact of a spherical object onto a surface of a liquid, solid or granular material, is a configuration which occurs in numerous industrial and natural phenomena. The resulting dynamics can produce complex outcomes and often occur on very short time-scales. Their study thereby requires high-speed video imaging, as is done herein. This three-part dissertation investigates widely disparate but kindred impact configurations, where the impacting object is a solid steel sphere, or a molten metal droplet. The substrate, on the other hand, is either granular material, a liquid, or solid ice. Therefore both fluid mechanics and thermodynamics play a key role in some of these dynamics. Part I, investigates the penetration depth of a steel sphere which impacts onto a granular bed containing a mixture of grains of two different sizes. The addition of smaller grains within a bed of larger grains can promote a “lubrication” effect and deeper penetration of the sphere. However, there needs to be enough mass fraction of the smaller grains so that they get lodged between the larger grains and are not simply like isolated rattlers inside the voids between the larger grains. This lubrication occurs even though the addition of the small grains increases the overall packing fraction of the bed. We compare the enhanced penetration for the mixtures to a simple interpolative model based on the results for monodispersed media of the constitutive sizes. The strongest lubrication is observed for large irregular shaped Ottawa sand grains, which are seeded with small spherical glass beads. Part II, tackles the topic of a molten metal drop impacting onto a pool of water. When the drop temperature is far above the boiling temperature of water, a continuous vapor layer can form at the interface between the metal and water, in what is called the Leidenfrost phenomenon. This vapor layer can become unstable forming what is called a vapor explosion, which can break up the molten metal drop

  5. Energy transfer from natural photosynthetic complexes to single-wall carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Wiwatowski, Kamil [Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun (Poland); Dużyńska, Anna; Świniarski, Michał [Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Szalkowski, Marcin [Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun (Poland); Zdrojek, Mariusz; Judek, Jarosław [Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Mackowski, Sebastian, E-mail: mackowski@fizyka.umk.pl [Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun (Poland); Wroclaw Research Center EIT+, Stablowicka 147, Wroclaw (Poland); Kaminska, Izabela [Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun (Poland)

    2016-02-15

    Combination of fluorescence imaging and spectroscopy results indicates that single-walled carbon nanotubes are extremely efficient quenchers of fluorescence emission associated with chlorophylls embedded in a natural photosynthetic complex, peridinin-chlorophyll-protein. When deposited on a network of the carbon nanotubes forming a thin film, the emission of the photosynthetic complexes diminishes almost completely. This strong reduction of fluorescence intensity is accompanied with dramatic shortening of the fluorescence lifetime. Concluding, such thin films of carbon nanotubes can be extremely efficient energy acceptors in structures involving biologically functional complexes. - Highlights: • Fluorescence imaging of carbon nanotube - based hybrid structure. • Observation of efficient energy transfer from chlorophylls to carbon nanotubes.

  6. Extreme accumulations of natural polonium-210 in certain marine organisms

    International Nuclear Information System (INIS)

    Folsom, T.R.; Wong, K.M.; Hodge, V.F.

    1972-01-01

    Concentration levels of polonium-210 reported for sea water are reviewed, and activities accumulated by various marine plant and animal species are discussed. Special mention is made of detailed studies of one giant algae upon whose outer surfaces intense accumulations of polonium have been discovered recently. Some concentrations found in two organisms intimate with algae, the abalones and the sea hares, are reported. Concentrations are listed pertaining to organisms selected from the open ocean in order to show that intense polonium concentrations are not restricted to organisms living near the continents where precursors of polonium originate. A brief discussion of conditions on one of the marine mammals, the dolphin, next is made. Then comments are made upon a benthic species (the sable fish) that prefers to live close to the deep sea floor, presumably so as to eat detritus. They also eat many of the smaller organisms that compete for the natural deep sea fallout of food, and many of these live in close contact with the muds and clays of the sea floor that are rich in radium. Some of the behavior and anatomical features and polonium-210 distribution in one of the most interesting and valuable of fishes, the North Pacific albacore (Thunnus alalunga) is described. This species has been used previously to tell us something about nuclear fallout distributions in the North Pacific Ocean during the past decade and repeatedly has directed attention to features of this ocean that might hardly be detected otherwise. (U.S.)

  7. Extreme disorder in an ultrahigh-affinity protein complex

    Science.gov (United States)

    Borgia, Alessandro; Borgia, Madeleine B.; Bugge, Katrine; Kissling, Vera M.; Heidarsson, Pétur O.; Fernandes, Catarina B.; Sottini, Andrea; Soranno, Andrea; Buholzer, Karin J.; Nettels, Daniel; Kragelund, Birthe B.; Best, Robert B.; Schuler, Benjamin

    2018-03-01

    Molecular communication in biology is mediated by protein interactions. According to the current paradigm, the specificity and affinity required for these interactions are encoded in the precise complementarity of binding interfaces. Even proteins that are disordered under physiological conditions or that contain large unstructured regions commonly interact with well-structured binding sites on other biomolecules. Here we demonstrate the existence of an unexpected interaction mechanism: the two intrinsically disordered human proteins histone H1 and its nuclear chaperone prothymosin-α associate in a complex with picomolar affinity, but fully retain their structural disorder, long-range flexibility and highly dynamic character. On the basis of closely integrated experiments and molecular simulations, we show that the interaction can be explained by the large opposite net charge of the two proteins, without requiring defined binding sites or interactions between specific individual residues. Proteome-wide sequence analysis suggests that this interaction mechanism may be abundant in eukaryotes.

  8. Extreme disorder in an ultrahigh-affinity protein complex

    DEFF Research Database (Denmark)

    Borgia, Alessandro; Borgia, Madeleine B; Bugge, Katrine

    2018-01-01

    Molecular communication in biology is mediated by protein interactions. According to the current paradigm, the specificity and affinity required for these interactions are encoded in the precise complementarity of binding interfaces. Even proteins that are disordered under physiological conditions...... with picomolar affinity, but fully retain their structural disorder, long-range flexibility and highly dynamic character. On the basis of closely integrated experiments and molecular simulations, we show that the interaction can be explained by the large opposite net charge of the two proteins, without requiring...... or that contain large unstructured regions commonly interact with well-structured binding sites on other biomolecules. Here we demonstrate the existence of an unexpected interaction mechanism: the two intrinsically disordered human proteins histone H1 and its nuclear chaperone prothymosin-α associate in a complex...

  9. Animal responses to natural disturbance and climate extremes: a review

    Science.gov (United States)

    Sergio, Fabrizio; Blas, Julio; Hiraldo, Fernando

    2018-02-01

    Natural disturbances, such as droughts, fires or hurricanes, are key drivers of ecological heterogeneity and ecosystem function. The frequency and severity of these episodes is unequivocally expected to increase in the coming decades, through the concerted action of climate change and anthropogenic pressures. This will impose severe challenges for many biota through exposure to rapidly changing conditions never experienced in the preceding millennia. Thus, it is urgently needed to gain a thorough understanding of animal responses and adaptations to disturbances in order to better estimate potential future impacts. Here, we review such adjustments and find that animals may respond to disturbances through changes in: (1) behaviour, such as altered mobility, emigration, resource-switching, refuge use, suspended animation, or biotic interactions; (2) life history traits, such as survival, aging, longevity, recruitment, reproductive restraint, breeding output, phenology and bet-hedging tactics; (3) morphology, such as rapid evolution through size-dependent mortality or facultative metamorphosis; (4) physiology, such as altered body condition, pathogen prevalence and transmission, or adrenocortical modulation of stress responses to emergency conditions; (5) genetic structure, such as changes in frequency of polymorphic variants or diversity-modulation through mortality bottlenecks. Individual-level responses scale up to population and community responses, such as altered density, population dynamics, distribution, local extinction and colonization, or assemblage structure and diversity. Overall, disturbances have pervasive effects on individuals, populations and communities of vertebrates and invertebrates of all realms, biomes, continents and ecosystems. Their rapidly increasing incidence and severity will bring unique study opportunities for researchers and novel, unpredictable challenges for managers, while demanding tougher choices and more proactive crisis

  10. Natural disasters and the challenge of extreme events: risk management from an insurance perspective

    Science.gov (United States)

    Smolka, Anselm

    2006-08-01

    Loss statistics for natural disasters demonstrate, also after correction for inflation, a dramatic increase of the loss burden since 1950. This increase is driven by a concentration of population and values in urban areas, the development of highly exposed coastal and valley regions, the complexity of modern societies and technologies and probably, also by the beginning consequences of global warming. This process will continue unless remedial action will be taken. Managing the risk from natural disasters starts with identification of the hazards. The next step is the evaluation of the risk, where risk is a function of hazard, exposed values or human lives and the vulnerability of the exposed objects. Probabilistic computer models have been developed for the proper assessment of risks since the late 1980s. The final steps are controlling and financing future losses. Natural disaster insurance plays a key role in this context, but also private parties and governments have to share a part of the risk. A main responsibility of governments is to formulate regulations for building construction and land use. The insurance sector and the state have to act together in order to create incentives for building and business owners to take loss prevention measures. A further challenge for the insurance sector is to transfer a portion of the risk to the capital markets, and to serve better the needs of the poor. Catastrophe bonds and microinsurance are the answer to such challenges. The mechanisms described above have been developed to cope with well-known disasters like earthquakes, windstorms and floods. They can be applied, in principle, also to less well investigated and less frequent extreme disasters: submarine slides, great volcanic eruptions, meteorite impacts and tsunamis which may arise from all these hazards. But there is an urgent need to improve the state of knowledge on these more exotic hazards in order to reduce the high uncertainty in actual risk evaluation to

  11. The complexity of natural gas contracts

    International Nuclear Information System (INIS)

    De Boer, A.

    2000-01-01

    In the process of the deregulation of the energy market large consumers will have lots of opportunities to purchase natural gas and electricity cheaper than before. However, only one third seizes those opportunities. Special consultants can help to conclude supply contracts, focusing on the customer, supplier and commodity. Advantages and disadvantages of collective purchases of energy are briefly outlined

  12. Is there Complex Trauma Experience typology for Australian's experiencing extreme social disadvantage and low housing stability?

    Science.gov (United States)

    Keane, Carol A; Magee, Christopher A; Kelly, Peter J

    2016-11-01

    Traumatic childhood experiences predict many adverse outcomes in adulthood including Complex-PTSD. Understanding complex trauma within socially disadvantaged populations has important implications for policy development and intervention implementation. This paper examined the nature of complex trauma experienced by disadvantaged individuals using a latent class analysis (LCA) approach. Data were collected through the large-scale Journeys Home Study (N=1682), utilising a representative sample of individuals experiencing low housing stability. Data on adverse childhood experiences, adulthood interpersonal trauma and relevant covariates were collected through interviews at baseline (Wave 1). Latent class analysis (LCA) was conducted to identify distinct classes of childhood trauma history, which included physical assault, neglect, and sexual abuse. Multinomial logistic regression investigated childhood relevant factors associated with class membership such as biological relationship of primary carer at age 14 years and number of times in foster care. Of the total sample (N=1682), 99% reported traumatic adverse childhood experiences. The most common included witnessing of violence, threat/experience of physical abuse, and sexual assault. LCA identified six distinct childhood trauma history classes including high violence and multiple traumas. Significant covariate differences between classes included: gender, biological relationship of primary carer at age 14 years, and time in foster care. Identification of six distinct childhood trauma history profiles suggests there might be unique treatment implications for individuals living in extreme social disadvantage. Further research is required to examine the relationship between these classes of experience, consequent impact on adulthood engagement, and future transitions though homelessness. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Extreme phenophase delays and their relationship with natural forcings in Beijing over the past 260 years

    Science.gov (United States)

    Liu, Yang; Zhang, Mingqing; Fang, Xiuqi

    2018-03-01

    By merging reconstructed phenological series from published articles and observations of China Phenology Observation Network (CPON), the first blooming date of Amygdalus davidiana (FBA) in Beijing between 1741 and 2000 is reconstructed. The Butterworth method is used to remove the multi-year variations for generating the phenological series of annual variations in the first blooming date of A. davidiana. The extreme delay years in the phenological series are identified using the percentage threshold method. The characteristics of the extreme delays and the correspondence of these events with natural forcings are analysed. The main results are as follows. In annual phenological series, the extreme delays appeared in single year as main feature, only A.D.1800-1801, 1816-1817 and 1983-1984 were the events of two consecutively extreme years. Approximately 85% of the extreme delays occurred during 1-2 years after the large volcanic eruptions (VEI ≥ 4) in the eastern rim or the western rim of the Pacific Ocean, as the same proportion of the extreme delays followed El Niño events. About 73% years of the extreme delays fall in the valleys of sunspot cycles or the Dalton minimum period in the year or the previous year. According to the certainty factor (CF), the large eruptions have the greatest influence to the extreme delays; sunspot activity is the second, and ENSO is the last one. The extreme phenological delayed year is most likely to occur after a large eruption, which particularly occurs during El Niño year and its previous several years were in the descending portion or valley of sunspot phase.

  14. Low Complexity Tail-Biting Trellises for Some Extremal Self-Dual Codes

    OpenAIRE

    Olocco , Grégory; Otmani , Ayoub

    2002-01-01

    International audience; We obtain low complexity tail-biting trellises for some extremal self-dual codes for various lengths and fields such as the [12,6,6] ternary Golay code and a [24,12,8] Hermitian self-dual code over GF(4). These codes are obtained from a particular family of cyclic Tanner graphs called necklace factor graphs.

  15. Shrinking the Synchrotron : Tabletop Extreme Ultraviolet Absorption of Transition-Metal Complexes

    NARCIS (Netherlands)

    Zhang, Kaili; Lin, Ming Fu; Ryland, Elizabeth S.; Verkamp, Max A.; Benke, Kristin; De Groot, Frank M F; Girolami, Gregory S.; Vura-Weis, Josh

    2016-01-01

    We show that the electronic structure of molecular first-row transition-metal complexes can be reliably measured using tabletop high-harmonic XANES at the metal M2,3 edge. Extreme ultraviolet photons in the 50-70 eV energy range probe 3p → 3d transitions, with the same selection rules as soft X-ray

  16. Patterns of precipitation and soil moisture extremes in Texas, US: A complex network analysis

    Science.gov (United States)

    Sun, Alexander Y.; Xia, Youlong; Caldwell, Todd G.; Hao, Zengchao

    2018-02-01

    Understanding of the spatial and temporal dynamics of extreme precipitation not only improves prediction skills, but also helps to prioritize hazard mitigation efforts. This study seeks to enhance the understanding of spatiotemporal covariation patterns embedded in precipitation (P) and soil moisture (SM) by using an event-based, complex-network-theoretic approach. Events concurrences are quantified using a nonparametric event synchronization measure, and spatial patterns of hydroclimate variables are analyzed by using several network measures and a community detection algorithm. SM-P coupling is examined using a directional event coincidence analysis measure that takes the order of event occurrences into account. The complex network approach is demonstrated for Texas, US, a region possessing a rich set of hydroclimate features and is frequented by catastrophic flooding. Gridded daily observed P data and simulated SM data are used to create complex networks of P and SM extremes. The uncovered high degree centrality regions and community structures are qualitatively in agreement with the overall existing knowledge of hydroclimate extremes in the study region. Our analyses provide new visual insights on the propagation, connectivity, and synchronicity of P extremes, as well as the SM-P coupling, in this flood-prone region, and can be readily used as a basis for event-driven predictive analytics for other regions.

  17. The extreme solar storm of May 1921: observations and a complex topological model

    Directory of Open Access Journals (Sweden)

    H. Lundstedt

    2015-01-01

    Full Text Available A complex solid torus model was developed in order to be able to study an extreme solar storm, the so-called "Great Storm" or "New York Railroad Storm" of May 1921, when neither high spatial and time resolution magnetic field measurements, solar flare nor coronal mass ejection observations were available. We suggest that a topological change happened in connection with the occurrence of the extreme solar storm. The solar storm caused one of the most severe space weather effects ever.

  18. Natural enemy interactions constrain pest control in complex agricultural landscapes.

    Science.gov (United States)

    Martin, Emily A; Reineking, Björn; Seo, Bumsuk; Steffan-Dewenter, Ingolf

    2013-04-02

    Biological control of pests by natural enemies is a major ecosystem service delivered to agriculture worldwide. Quantifying and predicting its effectiveness at large spatial scales is critical for increased sustainability of agricultural production. Landscape complexity is known to benefit natural enemies, but its effects on interactions between natural enemies and the consequences for crop damage and yield are unclear. Here, we show that pest control at the landscape scale is driven by differences in natural enemy interactions across landscapes, rather than by the effectiveness of individual natural enemy guilds. In a field exclusion experiment, pest control by flying insect enemies increased with landscape complexity. However, so did antagonistic interactions between flying insects and birds, which were neutral in simple landscapes and increasingly negative in complex landscapes. Negative natural enemy interactions thus constrained pest control in complex landscapes. These results show that, by altering natural enemy interactions, landscape complexity can provide ecosystem services as well as disservices. Careful handling of the tradeoffs among multiple ecosystem services, biodiversity, and societal concerns is thus crucial and depends on our ability to predict the functional consequences of landscape-scale changes in trophic interactions.

  19. Contributions of natural climate changes and human activities to the trend of extreme precipitation

    Science.gov (United States)

    Gao, Lu; Huang, Jie; Chen, Xingwei; Chen, Ying; Liu, Meibing

    2018-06-01

    This study focuses on the analysis of the nonstationarity characteristics of extreme precipitation and their attributions in the southeastern coastal region of China. The maximum daily precipitation (MDP) series is extracted from observations at 79 meteorological stations in the study area during the first flood season (April-June) from 1960 to 2012. The trends of the mean (Mn) and variance (Var) of MDP are detected using the Generalized Additive Models for Location, Scale, and Shape parameters (GAMLSS) and Mann-Kendall test. The contributions of natural climate change and human activities to the Mn and Var changes of MDP are investigated using six large-scale circulation variables and emissions of four greenhouse gases based on GAMLSS and a contribution analysis method. The results demonstrate that the nonstationarity of extreme precipitation on local scales is significant. The Mn and Var of extreme precipitation increase in the north of Zhejiang, the middle of Fujian, and the south of Guangdong. In general, natural climate change contributes more to Mn from 1960 to 2012 than to Var. However, human activities cause a greater Var in the rapid socioeconomic development period (1986-2012) than in the slow socioeconomic development period (1960-1985), especially in Zhejiang and Guangdong. The community should pay more attention to the possibility of extreme precipitation events and associated disasters triggered by human activities.

  20. Current status and issues of external event PSA for extreme natural hazards after Fukushima accident

    International Nuclear Information System (INIS)

    Choi, In-Kil; Hahm, Daegi; Kim, Min Kyu

    2014-01-01

    Extreme external events is emerged as significant risk contributor to the nuclear power plants after Fukushima Daiichi accident due to the catastrophic earthquake followed by great tsunami greater than a design basis. This accident shows that the extreme external events have the potential to simultaneously affect redundant and diverse safety systems and thereby induce common cause failure or common cause initiators. The probabilistic risk assessment methodology has been used for the risk assessment and safety improvement against the extreme natural hazards. The earthquake and tsunami hazard is an important issue for the nuclear industry in Korea. In this paper, the role and application of probabilistic safety assessment for the post Fukushima action will be introduced. For the evaluation of the extreme natural hazard, probabilistic seismic and tsunami hazard analysis is being performed for the safety enhancement. The research activity on the external event PSA and its interim results will be introduced with the issues to be solved in the future for the reliability enhancement of the risk analysis results. (authors)

  1. Complex layered dental restorations: Are they recognizable and do they survive extreme conditions?

    Science.gov (United States)

    Soon, Alistair S; Bush, Mary A; Bush, Peter J

    2015-09-01

    Recent research has shown that restorative dental materials can be recognized by microscopy and elemental analysis (scanning electron microscopy/energy dispersive X-ray spectroscopy and X-ray fluorescence; SEM/EDS and XRF) and that this is possible even in extreme conditions, such as cremation. These analytical methods and databases of dental materials properties have proven useful in DVI (disaster victim identification) of a commercial plane crash in 2009, and in a number of other victim identification cases. Dental materials appear on the market with ever expanding frequency. With their advent, newer methods of restoration have been proposed and adopted in the dental office. Methods might include placing multiple layers of dental materials, where they have different properties including adhesion, viscosity, or working time. These different dental materials include filled adhesives, flowable resins, glass ionomer cements, composite resins, liners and sealants. With possible combinations of different materials in these restorations, the forensic odontologist is now confronted with a new difficulty; how to recognize each individual material. The question might be posed if it is even possible to perform this task. Furthermore, an odontologist might be called upon to identify a victim under difficult circumstances, such as when presented with fragmented or incinerated remains. In these circumstances the ability to identify specific dental materials could assist in the identification of the deceased. Key to use of this information is whether these new materials and methods are detailed in the dental chart. Visual or radiographic inspection may not reveal the presence of a restoration, let alone the possible complex nature of that restoration. This study demonstrates another scientific method in forensic dental identification. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. Observational constraints of stellar collapse: Diagnostic probes of nature's extreme matter experiment

    Directory of Open Access Journals (Sweden)

    Chris L. Fryer

    2014-04-01

    Full Text Available Supernovae are Nature's high-energy, high density laboratory experiments, reaching densities in excess of nuclear densities and temperatures above 10 MeV. Astronomers have built up a suite of diagnostics to study these supernovae. If we can utilize these diagnostics, and tie them together with a theoretical understanding of supernova physics, we can use these cosmic explosions to study the nature of matter at these extreme densities and temperatures. Capitalizing on these diagnostics will require understanding a wide range of additional physics. Here we review the diagnostics and the physics neeeded to use them to learn about the supernova engine, and ultimate nuclear physics.

  3. Complex active regions as the main source of extreme and large solar proton events

    Science.gov (United States)

    Ishkov, V. N.

    2013-12-01

    A study of solar proton sources indicated that solar flare events responsible for ≥2000 pfu proton fluxes mostly occur in complex active regions (CARs), i.e., in transition structures between active regions and activity complexes. Different classes of similar structures and their relation to solar proton events (SPEs) and evolution, depending on the origination conditions, are considered. Arguments in favor of the fact that sunspot groups with extreme dimensions are CARs are presented. An analysis of the flare activity in a CAR resulted in the detection of "physical" boundaries, which separate magnetic structures of the same polarity and are responsible for the independent development of each structure.

  4. An archaeal tRNA-synthetase complex that enhances aminoacylation under extreme conditions

    DEFF Research Database (Denmark)

    Godinic-Mikulcic, Vlatka; Jaric, Jelena; Hausmann, Corinne D

    2011-01-01

    Aminoacyl-tRNA synthetases (aaRSs) play an integral role in protein synthesis, functioning to attach the correct amino acid with its cognate tRNA molecule. AaRSs are known to associate into higher-order multi-aminoacyl-tRNA synthetase complexes (MSC) involved in archaeal and eukaryotic translatio...... of a complex between MtSerRS and MtArgRS provides a means by which methanogenic archaea can optimize an early step in translation under a wide range of extreme environmental conditions....

  5. Complexes of actinides with naturally occuring organic substances - Literature survey

    International Nuclear Information System (INIS)

    Olofsson, U.; Allard, B.

    1983-02-01

    Properties of naturally occurring humic and fulvic acids and their formation of actinide complexes are reviewed. Actinides in all the oxdation states III, IV, V and VI would form complexes with many humic and fulvic acids, comparable in strength to the hydroxide and carbonate complexes. Preliminary experiments have shown, that the presence of predominantly humic acid complexes would significantly reduce the sorption of americium on geologic media. This does not, however, necessarily lead to a potentially enhanced mobility under environmental conditions, since humic and fulvic acids carrying trace metals also would be strongly bound to e.g. clayish material. (author)

  6. Data-assisted reduced-order modeling of extreme events in complex dynamical systems.

    Directory of Open Access Journals (Sweden)

    Zhong Yi Wan

    Full Text Available The prediction of extreme events, from avalanches and droughts to tsunamis and epidemics, depends on the formulation and analysis of relevant, complex dynamical systems. Such dynamical systems are characterized by high intrinsic dimensionality with extreme events having the form of rare transitions that are several standard deviations away from the mean. Such systems are not amenable to classical order-reduction methods through projection of the governing equations due to the large intrinsic dimensionality of the underlying attractor as well as the complexity of the transient events. Alternatively, data-driven techniques aim to quantify the dynamics of specific, critical modes by utilizing data-streams and by expanding the dimensionality of the reduced-order model using delayed coordinates. In turn, these methods have major limitations in regions of the phase space with sparse data, which is the case for extreme events. In this work, we develop a novel hybrid framework that complements an imperfect reduced order model, with data-streams that are integrated though a recurrent neural network (RNN architecture. The reduced order model has the form of projected equations into a low-dimensional subspace that still contains important dynamical information about the system and it is expanded by a long short-term memory (LSTM regularization. The LSTM-RNN is trained by analyzing the mismatch between the imperfect model and the data-streams, projected to the reduced-order space. The data-driven model assists the imperfect model in regions where data is available, while for locations where data is sparse the imperfect model still provides a baseline for the prediction of the system state. We assess the developed framework on two challenging prototype systems exhibiting extreme events. We show that the blended approach has improved performance compared with methods that use either data streams or the imperfect model alone. Notably the improvement is more

  7. Data-assisted reduced-order modeling of extreme events in complex dynamical systems.

    Science.gov (United States)

    Wan, Zhong Yi; Vlachas, Pantelis; Koumoutsakos, Petros; Sapsis, Themistoklis

    2018-01-01

    The prediction of extreme events, from avalanches and droughts to tsunamis and epidemics, depends on the formulation and analysis of relevant, complex dynamical systems. Such dynamical systems are characterized by high intrinsic dimensionality with extreme events having the form of rare transitions that are several standard deviations away from the mean. Such systems are not amenable to classical order-reduction methods through projection of the governing equations due to the large intrinsic dimensionality of the underlying attractor as well as the complexity of the transient events. Alternatively, data-driven techniques aim to quantify the dynamics of specific, critical modes by utilizing data-streams and by expanding the dimensionality of the reduced-order model using delayed coordinates. In turn, these methods have major limitations in regions of the phase space with sparse data, which is the case for extreme events. In this work, we develop a novel hybrid framework that complements an imperfect reduced order model, with data-streams that are integrated though a recurrent neural network (RNN) architecture. The reduced order model has the form of projected equations into a low-dimensional subspace that still contains important dynamical information about the system and it is expanded by a long short-term memory (LSTM) regularization. The LSTM-RNN is trained by analyzing the mismatch between the imperfect model and the data-streams, projected to the reduced-order space. The data-driven model assists the imperfect model in regions where data is available, while for locations where data is sparse the imperfect model still provides a baseline for the prediction of the system state. We assess the developed framework on two challenging prototype systems exhibiting extreme events. We show that the blended approach has improved performance compared with methods that use either data streams or the imperfect model alone. Notably the improvement is more significant in

  8. Joint probability safety assessment for NPP defense infrastructure against extreme external natural hazards

    International Nuclear Information System (INIS)

    Guilin, L.; Defu, L.; Huajun, L.; Fengqing, W.; Tao, Z.

    2012-01-01

    With the increasing tendency of natural hazards, the typhoon, hurricane and tropical Cyclone induced surge, wave, precipitation, flood and wind as extreme external loads menacing Nuclear Power Plants (NPP) in coastal and inland provinces of China. For all of planned, designed And constructed NPP the National Nuclear Safety Administration of China and IAEA recommended Probable Maximum Hurricane /Typhoon/(PMH/T), Probable Maximum Storm Surge (PMSS), Probable Maximum Flood (PMF), Design Basis Flood (DBF) as safety regulations for NPP defense infrastructures. This paper discusses the joint probability analysis of simultaneous occurrence typhoon induced extreme external hazards and compare with IAEA 2006-2009 recommended safety regulation design criteria for some NPP defense infrastructures along China coast. (authors)

  9. Natural Product Screening Reveals Naphthoquinone Complex I Bypass Factors.

    Directory of Open Access Journals (Sweden)

    Scott B Vafai

    Full Text Available Deficiency of mitochondrial complex I is encountered in both rare and common diseases, but we have limited therapeutic options to treat this lesion to the oxidative phosphorylation system (OXPHOS. Idebenone and menadione are redox-active molecules capable of rescuing OXPHOS activity by engaging complex I-independent pathways of entry, often referred to as "complex I bypass." In the present study, we created a cellular model of complex I deficiency by using CRISPR genome editing to knock out Ndufa9 in mouse myoblasts, and utilized this cell line to develop a high-throughput screening platform for novel complex I bypass factors. We screened a library of ~40,000 natural product extracts and performed bioassay-guided fractionation on a subset of the top scoring hits. We isolated four plant-derived 1,4-naphthoquinone complex I bypass factors with structural similarity to menadione: chimaphilin and 3-chloro-chimaphilin from Chimaphila umbellata and dehydro-α-lapachone and dehydroiso-α-lapachone from Stereospermum euphoroides. We also tested a small number of structurally related naphthoquinones from commercial sources and identified two additional compounds with complex I bypass activity: 2-methoxy-1,4-naphthoquinone and 2-methoxy-3-methyl-1,4,-naphthoquinone. The six novel complex I bypass factors reported here expand this class of molecules and will be useful as tool compounds for investigating complex I disease biology.

  10. Using Plants to Explore the Nature & Structural Complexity of Life

    Science.gov (United States)

    Howard, Ava R.

    2014-01-01

    Use of real specimens brings the study of biology to life. This activity brings easily acquired plant specimens into the classroom to tackle common alternative conceptions regarding life, size, complexity, the nature of science, and plants as multicellular organisms. The activity occurs after a discussion of the characteristics of life and engages…

  11. Model of geophysical fields representation in problems of complex correlation-extreme navigation

    Directory of Open Access Journals (Sweden)

    Volodymyr KHARCHENKO

    2015-09-01

    Full Text Available A model of the optimal representation of spatial data for the task of complex correlation-extreme navigation is developed based on the criterion of minimum deviation of the correlation functions of the original and the resulting fields. Calculations are presented for one-dimensional case using the approximation of the correlation function by Fourier series. It is shown that in the presence of different geophysical map data fields their representation is possible by single template with optimal sampling without distorting the form of the correlation functions.

  12. The Hidden Complexity of Mendelian Traits across Natural Yeast Populations

    Directory of Open Access Journals (Sweden)

    Jing Hou

    2016-07-01

    Full Text Available Mendelian traits are considered to be at the lower end of the complexity spectrum of heritable phenotypes. However, more than a century after the rediscovery of Mendel’s law, the global landscape of monogenic variants, as well as their effects and inheritance patterns within natural populations, is still not well understood. Using the yeast Saccharomyces cerevisiae, we performed a species-wide survey of Mendelian traits across a large population of isolates. We generated offspring from 41 unique parental pairs and analyzed 1,105 cross/trait combinations. We found that 8.9% of the cases were Mendelian. Further tracing of causal variants revealed background-specific expressivity and modified inheritances, gradually transitioning from Mendelian to complex traits in 30% of the cases. In fact, when taking into account the natural population diversity, the hidden complexity of traits could be substantial, confounding phenotypic predictability even for simple Mendelian traits.

  13. Undersampling power-law size distributions: effect on the assessment of extreme natural hazards

    Science.gov (United States)

    Geist, Eric L.; Parsons, Thomas E.

    2014-01-01

    The effect of undersampling on estimating the size of extreme natural hazards from historical data is examined. Tests using synthetic catalogs indicate that the tail of an empirical size distribution sampled from a pure Pareto probability distribution can range from having one-to-several unusually large events to appearing depleted, relative to the parent distribution. Both of these effects are artifacts caused by limited catalog length. It is more difficult to diagnose the artificially depleted empirical distributions, since one expects that a pure Pareto distribution is physically limited in some way. Using maximum likelihood methods and the method of moments, we estimate the power-law exponent and the corner size parameter of tapered Pareto distributions for several natural hazard examples: tsunamis, floods, and earthquakes. Each of these examples has varying catalog lengths and measurement thresholds, relative to the largest event sizes. In many cases where there are only several orders of magnitude between the measurement threshold and the largest events, joint two-parameter estimation techniques are necessary to account for estimation dependence between the power-law scaling exponent and the corner size parameter. Results indicate that whereas the corner size parameter of a tapered Pareto distribution can be estimated, its upper confidence bound cannot be determined and the estimate itself is often unstable with time. Correspondingly, one cannot statistically reject a pure Pareto null hypothesis using natural hazard catalog data. Although physical limits to the hazard source size and by attenuation mechanisms from source to site constrain the maximum hazard size, historical data alone often cannot reliably determine the corner size parameter. Probabilistic assessments incorporating theoretical constraints on source size and propagation effects are preferred over deterministic assessments of extreme natural hazards based on historic data.

  14. Game theory and extremal optimization for community detection in complex dynamic networks.

    Science.gov (United States)

    Lung, Rodica Ioana; Chira, Camelia; Andreica, Anca

    2014-01-01

    The detection of evolving communities in dynamic complex networks is a challenging problem that recently received attention from the research community. Dynamics clearly add another complexity dimension to the difficult task of community detection. Methods should be able to detect changes in the network structure and produce a set of community structures corresponding to different timestamps and reflecting the evolution in time of network data. We propose a novel approach based on game theory elements and extremal optimization to address dynamic communities detection. Thus, the problem is formulated as a mathematical game in which nodes take the role of players that seek to choose a community that maximizes their profit viewed as a fitness function. Numerical results obtained for both synthetic and real-world networks illustrate the competitive performance of this game theoretical approach.

  15. Community detection in complex networks using deep auto-encoded extreme learning machine

    Science.gov (United States)

    Wang, Feifan; Zhang, Baihai; Chai, Senchun; Xia, Yuanqing

    2018-06-01

    Community detection has long been a fascinating topic in complex networks since the community structure usually unveils valuable information of interest. The prevalence and evolution of deep learning and neural networks have been pushing forward the advancement in various research fields and also provide us numerous useful and off the shelf techniques. In this paper, we put the cascaded stacked autoencoders and the unsupervised extreme learning machine (ELM) together in a two-level embedding process and propose a novel community detection algorithm. Extensive comparison experiments in circumstances of both synthetic and real-world networks manifest the advantages of the proposed algorithm. On one hand, it outperforms the k-means clustering in terms of the accuracy and stability thus benefiting from the determinate dimensions of the ELM block and the integration of sparsity restrictions. On the other hand, it endures smaller complexity than the spectral clustering method on account of the shrinkage in time spent on the eigenvalue decomposition procedure.

  16. Peroneal island flap for wound coverage in complex injuries of the lower extremity

    Directory of Open Access Journals (Sweden)

    Fazal A

    2012-01-01

    Full Text Available Akil Fazal1, Haroon-ur-Rashid1, Tahseen Cheema21Section of Orthopedics, Department of Surgery, Aga Khan University, Karachi, Pakistan; 2Department of Orthopedics and Rehabilitation, University of New Mexico, Albuquerque, NM, USABackground: Complex injuries of the lower extremity pose a therapeutic challenge owing to limited availability of local soft tissue for coverage. One option in this region is the pedicled fasciocutaneous flap based on perforators of the peroneal artery. In this case series, we present our experience of the peroneal island pedicled flap for reconstruction of lower extremity wounds.Methods: Records of 18 cases of peroneal island flap admitted consecutively to the Section of Orthopedics at Aga Khan University Hospital from January 1996 to December of 2009 were studied and their outcomes determined.Results: The most common indication for coverage was open wounds due to a road traffic accident (n = 10, followed by burns (n = 3. The most common area exposed was the lower third of the leg followed by the middle third. The tibia was exposed in 11 patients. The flaps ranged in size from 35 cm2 to over 200 cm2. In 13 patients, the flaps healed uneventfully, while in the remaining five there was partial flap necrosis. In four of the latter patients, the residual wound healed with conservative measures only, but the fifth patient required further surgery to achieve acceptable coverage.Conclusion: The peroneal artery flap appears to be a simple, useful, and reliable flap in the armamentarium of the surgeon when planning soft tissue coverage of the lower extremity.Keywords: leg injuries, surgical flaps, lower extremity

  17. Generalized Extreme Value's shape parameter and its nature for extreme precipitation using long time series and Bayesian approach

    Science.gov (United States)

    Ragulina, Galina; Reitan, Trond

    2016-04-01

    Assessing the probability of extreme precipitation events is of great importance in civil planning. This requires understanding of how return values change with different return periods, which is essentially described by the Generalized Extreme Value distribution's shape parameter. Some works in the field have suggested a constant shape parameter, while our analysis indicates a non-universal value. We first re-analyse an older precipitation dataset (169 stations) extended by Norwegian data (71 stations). We show that while each set seems to have a constant shape parameter, it differs between the two datasets, indicating regional differences. For a more comprehensive analysis of spatial effects, we examine a global dataset (1495 stations). We provide shape parameter maps for two models. We find clear evidence for the shape parameter being dependent on elevation while the effect of latitude remains uncertain. Our results confirm an explanation in terms of dominating precipitation systems based on a proxy derived from the Köppen-Geiger climate classification.

  18. Synchronization and Causality Across Time-scales: Complex Dynamics and Extremes in El Niño/Southern Oscillation

    Science.gov (United States)

    Jajcay, N.; Kravtsov, S.; Tsonis, A.; Palus, M.

    2017-12-01

    A better understanding of dynamics in complex systems, such as the Earth's climate is one of the key challenges for contemporary science and society. A large amount of experimental data requires new mathematical and computational approaches. Natural complex systems vary on many temporal and spatial scales, often exhibiting recurring patterns and quasi-oscillatory phenomena. The statistical inference of causal interactions and synchronization between dynamical phenomena evolving on different temporal scales is of vital importance for better understanding of underlying mechanisms and a key for modeling and prediction of such systems. This study introduces and applies information theory diagnostics to phase and amplitude time series of different wavelet components of the observed data that characterizes El Niño. A suite of significant interactions between processes operating on different time scales was detected, and intermittent synchronization among different time scales has been associated with the extreme El Niño events. The mechanisms of these nonlinear interactions were further studied in conceptual low-order and state-of-the-art dynamical, as well as statistical climate models. Observed and simulated interactions exhibit substantial discrepancies, whose understanding may be the key to an improved prediction. Moreover, the statistical framework which we apply here is suitable for direct usage of inferring cross-scale interactions in nonlinear time series from complex systems such as the terrestrial magnetosphere, solar-terrestrial interactions, seismic activity or even human brain dynamics.

  19. Assessing Nature-Based Coastal Protection against Disasters Derived from Extreme Hydrometeorological Events in Mexico

    Directory of Open Access Journals (Sweden)

    Octavio Pérez-Maqueo

    2018-04-01

    Full Text Available Natural ecosystems are expected to reduce the damaging effects of extreme hydrometeorological effects. We tested this prediction for Mexico by performing regression models, with two dependent variables: the occurrence of deaths and economic damages, at a state and municipality levels. For each location, the explanatory variables were the Mexican social vulnerability index (which includes socioeconomic aspects, local capacity to prevent and respond to an emergency, and the perception of risk and land use cover considering different vegetation types. We used the hydrometeorological events that have affected Mexico from 1970 to 2011. Our findings reveal that: (a hydrometeorological events affect both coastal and inland states, although damages are greater on the coast; (b the protective role of natural ecosystems only was clear at a municipality level: the presence of mangroves, tropical dry forest and tropical rainforest was related to a significant reduction in the occurrence of casualties. Social vulnerability was positively correlated with the occurrence of deaths. Natural ecosystems, both typically coastal (mangroves and terrestrial (tropical forests, which are located on the mountain ranges close to the coast function for storm protection. Thus, their conservation and restoration are effective and sustainable strategies that will help protect and develop the increasingly urbanized coasts.

  20. Divisibility patterns of natural numbers on a complex network.

    Science.gov (United States)

    Shekatkar, Snehal M; Bhagwat, Chandrasheel; Ambika, G

    2015-09-16

    Investigation of divisibility properties of natural numbers is one of the most important themes in the theory of numbers. Various tools have been developed over the centuries to discover and study the various patterns in the sequence of natural numbers in the context of divisibility. In the present paper, we study the divisibility of natural numbers using the framework of a growing complex network. In particular, using tools from the field of statistical inference, we show that the network is scale-free but has a non-stationary degree distribution. Along with this, we report a new kind of similarity pattern for the local clustering, which we call "stretching similarity", in this network. We also show that the various characteristics like average degree, global clustering coefficient and assortativity coefficient of the network vary smoothly with the size of the network. Using analytical arguments we estimate the asymptotic behavior of global clustering and average degree which is validated using numerical analysis.

  1. Vacuum assisted closure therapy for treatment of complex wounds in replanted extremities.

    Science.gov (United States)

    Zhou, Min; Qi, Baiwen; Yu, Aixi; Pan, Zhenyu; Zhu, Shaobo; Deng, Kai; Tao, Shengxiang

    2013-11-01

    The object of this study was to compare the outcomes of the vacuum assisted closure (VAC) therapy and conventional wound care with dressing change for treatment of complex wounds in patients with replantation of amputated upper and lower extremities. Data of 43 patients with replantation of amputated extremities from May 2004 to December 2011 were reviewed. There were 18 wounds of 18 patients with replantation, which were treated by dressing change and 26 wounds of 25 patients by VAC therapy. The outcomes were evaluated by the survival rate of replanted extremities, growth of granulation tissue, interval between wound treatment and secondary procedure and eventual secondary wound coverage methods. Vascular thromboses were found in 3 patients with wound treatment by dressing change and 5 by VAC. All replants of two groups of patients survived after salvage procedures. The wound score was 3.6 ± 0.7 in the conventional dressing change group and 5.8 ± 0.7 in the VAC group at the sixth day after treatment, respectively. The intervals between wound treatment and secondary wound coverage procedure were 12.0 ± 1.7 days in the dressing change group and 6.1 ± 0.7 days in the VAC group. Flaps were applied for wound coverage in 9 out of 18 (50.0%) wounds in the dressing change group and 5 out of 26 (19.2%) in the VAC group (P VAC could promote the growth of granulation tissue of wound, decrease the need of flap for wound coverage, and did not change the survival of replantation. Copyright © 2013 Wiley Periodicals, Inc.

  2. THE NATURE OF EXTREMELY RED H - [4.5] > 4 GALAXIES REVEALED WITH SEDS AND CANDELS

    Energy Technology Data Exchange (ETDEWEB)

    Caputi, K. I.; Dunlop, J. S.; McLure, R. J.; Cirasuolo, M. [SUPA, Institute for Astronomy, The University of Edinburgh, Royal Observatory, Edinburgh EH9 3HJ (United Kingdom); Huang, J.-S.; Fazio, G. G.; Ashby, M. L. N. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Castellano, M.; Fontana, A. [INAF-Osservatorio Astronomico di Roma, Via Frascati 33, I-00040 Monteporzio (Italy); Almaini, O. [School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom); Bell, E. F. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Dickinson, M. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Donley, J. L.; Ferguson, H. C.; Grogin, N. A.; Koekemoer, A. M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Faber, S. M.; Kocevski, D. D.; Koo, D. C. [University of California Observatories/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Giavalisco, M., E-mail: karina@astro.rug.nl [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); and others

    2012-05-01

    We have analyzed a sample of 25 extremely red H - [4.5] > 4 galaxies, selected using 4.5 {mu}m data from the Spitzer SEDS survey and deep H-band data from the Hubble Space Telescope CANDELS survey, over {approx}180 arcmin{sup 2} of the UKIDSS Ultra-Deep Survey field. Our aim is to investigate the nature of this rare population of mid-infrared (mid-IR) sources that display such extreme near-to-mid-IR colors. Using up to 17-band photometry (U through 8.0 {mu}m), we have studied in detail their spectral energy distributions, including possible degeneracies in the photometric redshift/internal extinction (z{sub phot}-A{sub V} ) plane. Our sample appears to include sources of very different nature. Between 45% and 75% of them are dust-obscured, massive galaxies at 3 < z{sub phot} < 5. All of the 24 {mu}m detected sources in our sample are in this category. Two of these have S(24 {mu}m)>300 {mu}Jy, which at 3 < z{sub phot} < 5 suggests that they probably host a dust-obscured active galactic nucleus. Our sample also contains four highly obscured (A{sub V} > 5) sources at z{sub phot} < 1. Finally, we analyze in detail two z{sub phot} {approx} 6 galaxy candidates, and discuss their plausibility and implications. Overall, our red galaxy sample contains the tip of the iceberg of a larger population of z > 3 galaxies to be discovered with the future James Webb Space Telescope.

  3. Variable complexity online sequential extreme learning machine, with applications to streamflow prediction

    Science.gov (United States)

    Lima, Aranildo R.; Hsieh, William W.; Cannon, Alex J.

    2017-12-01

    In situations where new data arrive continually, online learning algorithms are computationally much less costly than batch learning ones in maintaining the model up-to-date. The extreme learning machine (ELM), a single hidden layer artificial neural network with random weights in the hidden layer, is solved by linear least squares, and has an online learning version, the online sequential ELM (OSELM). As more data become available during online learning, information on the longer time scale becomes available, so ideally the model complexity should be allowed to change, but the number of hidden nodes (HN) remains fixed in OSELM. A variable complexity VC-OSELM algorithm is proposed to dynamically add or remove HN in the OSELM, allowing the model complexity to vary automatically as online learning proceeds. The performance of VC-OSELM was compared with OSELM in daily streamflow predictions at two hydrological stations in British Columbia, Canada, with VC-OSELM significantly outperforming OSELM in mean absolute error, root mean squared error and Nash-Sutcliffe efficiency at both stations.

  4. Conformational changes in the bilirubin-human serum albumin complex at extreme alkaline pH

    DEFF Research Database (Denmark)

    Honoré, B; Frandsen, P C

    1986-01-01

    Light-absorption, c.d. and fluorescence of the bilirubin-albumin complex were investigated at extreme alkaline pH. Above pH 11.1 albumin binds the bilirubin molecule, twisted oppositely to the configuration at more neutral pH. On the basis of light-absorption it is shown that two alkaline...... transitions occur. The first alkaline transition takes place at pH between 11.3 and 11.8, co-operatively dissociating at least six protons. The second alkaline transition takes place at pH between 11.8 and 12.0. It probably implies a reversible unfolding of the albumin molecule, increasing the distance...

  5. Compound extremes of summer temperature and precipitation leading to intensified departures from natural variability.

    Science.gov (United States)

    Mahony, C. R.; Cannon, A. J.

    2017-12-01

    Climate change can drive local climates outside the range of their historical year-to-year variability, straining the adaptive capacity of ecological and human communities. We demonstrate that interactions between climate variables can produce larger and earlier departures from natural variability than is detectable in individual variables. For example, summer temperature (Tx) and precipitation (Pr) are negatively correlated in most terrestrial regions, such that interannual variability lies along an axis from warm-and-dry to cool-and-wet conditions. A climate change trend perpendicular to this axis, towards warmer-wetter conditions, can depart more quickly from the range of natural variability than a warmer-drier trend. This multivariate "departure intensification" effect is evident in all six CMIP5 models that we examined: 23% (9-34%) of the land area of each model exhibits a pronounced increase in 2σ extremesin the Tx-Pr regime relative to Tx or Pr alone. Observational data suggest that Tx-Pr correlations are sufficient to produce departure intensification in distinct regions on all continents. Departures from the historical Tx-Pr regime may produce ecological disruptions, such as in plant-pathogen interactions and human diseases, that could offset the drought mitigation benefits of increased precipitation. Our study alerts researchers and adaptation practitioners to the presence of multivariate climate change signals and compound extremes that are not detectable in individual climate variables.

  6. Aortic dissection: natural course of disease? Report of two cases representing the extremes of the condition

    International Nuclear Information System (INIS)

    Tollefsen, Isak; Joergensen, Ingrid K.; Woie, Leik; Fossdal, Jan E.

    2001-01-01

    Objective: In a time when diagnostic methods and above all, surgical as well as interventional radiological treatment for aortic aneurysms and aortic dissections have reached a point nobody could think of a few years back, the present authors feel that it is worth while to remind oneself of the natural course of disease in these conditions. Taking into consideration the high morbidity and mortality rate in surgically treated patients with aortic dissection, and the high complication rate per- and postoperatively, it also seems right to ask if a more expectative and conservative approach to the condition sometimes perhaps may be justified. Methods and material: Two case reports are given. One was a 15-year-old boy with Stanford (Daily) type B dissection who statistically ought to have a good prognosis, but who died within 2 h after onset of symptoms. The other patient, a middle-aged woman with Stanford type A dissection, survived for 25 years without operation. Conclusion: These two cases, though not unique viewed separately, we consider to represent the extremes of the condition and also a natural course of disease, while none of them was operated on

  7. Aortic dissection: natural course of disease? Report of two cases representing the extremes of the condition.

    Science.gov (United States)

    Tollefsen, I; Jørgensen, I K; Woie, L; Fossdal, J E

    2001-10-01

    In a time when diagnostic methods and above all, surgical as well as interventional radiological treatment for aortic aneurysms and aortic dissections have reached a point nobody could think of a few years back, the present authors feel that it is worth while to remind oneself of the natural course of disease in these conditions. Taking into consideration the high morbidity and mortality rate in surgically treated patients with aortic dissection, and the high complication rate per- and postoperatively, it also seems right to ask if a more expectative and conservative approach to the condition sometimes perhaps may be justified. Two case reports are given. One was a 15-year-old boy with Stanford (Daily) type B dissection who statistically ought to have a good prognosis, but who died within 2 h after onset of symptoms. The other patient, a middle-aged woman with Stanford type A dissection, survived for 25 years without operation. These two cases, though not unique viewed separately, we consider to represent the extremes of the condition and also a natural course of disease, while none of them was operated on.

  8. Communicating natural hazards. The case of marine extreme events and the importance of the forecast's errors.

    Science.gov (United States)

    Marone, Eduardo; Camargo, Ricardo

    2013-04-01

    Scientific knowledge has to fulfill some necessary conditions. Among them, it has to be properly communicated. Usually, scientists (mis)understand that the communication requirement is satisfied by publishing their results on peer reviewed journals. Society claims for information in other formats or languages and other tools and approaches have to be used, otherwise the scientific discoveries will not fulfill its social mean. However, scientists are not so well trained to do so. These facts are particularly relevant when the scientific work has to deal with natural hazards, which do not affect just a lab or a computer experiment, but the life and fate of human beings. We are actually working with marine extreme events related with sea level changes, waves and other coastal hazards. Primary, the work is developed on the classic scientific format, but focusing not only in the stochastic way of predicting such extreme events, but estimating the potential errors the forecasting methodologies intrinsically have. The scientific results are translated to a friendly format required by stakeholders (which are financing part of the work). Finally, we hope to produce a document prepared for the general public. Each of the targets has their own characteristics and we have to use the proper communication tools and languages. Also, when communicating such knowledge, we have to consider that stakeholders and general public have no obligation of understanding the scientific language, but scientists have the responsibility of translating their discoveries and predictions in a proper way. The information on coastal hazards is analyzed in statistical and numerical ways, departing from long term observation of, for instance, sea level. From the analysis it is possible to recognize different natural regimes and to present the return times of extreme events, while from the numerical models, properly tuned to reproduce the same past ocean behavior using hindcast approaches, it is

  9. Mercury reduction and complexation by natural organic matter

    International Nuclear Information System (INIS)

    Gu, Baohua; Bian, Yongrong; Miller, Carrie L.; Dong, Wenming; Jiang, Xin; Liang, Liyuan

    2011-01-01

    Mercuric Hg(II) species form complexes with natural dissolved organic matter (DOM) such as humic acid (HA), and this binding is known to affect the chemical and biological transformation and cycling of mercury in aquatic environments. Dissolved elemental mercury, Hg(0), is also widely observed in sediments and water. However, reactions between Hg(0) and DOM have rarely been studied in anoxic environments. Here, under anoxic dark conditions we show strong interactions between reduced HA and Hg(0) through thiol-ligand induced oxidative complexation with an estimated binding capacity of about 3.5 umol Hg(0)/g HA and a partitioning coefficient greater than 10 6 mL/g. We further demonstrate that Hg(II) can be effectively reduced to Hg(0) in the presence of as little as 0.2 mg/L reduced HA, whereas production of purgeable Hg(0) is inhibited by complexation as HA concentration increases. This dual role played by DOM in the reduction and complexation of mercury is likely widespread in anoxic sediments and water and can be expected to significantly influence the mercury species transformations and biological uptake that leads to the formation of toxic methylmercury.

  10. Complex forming properties of natural organic acids. Pt. 2

    International Nuclear Information System (INIS)

    Ephraim, J.H.; Mathuthu, A.S.; Marinsky, J.A.

    1990-07-01

    An ultrafiltration technique combined with ion-selective-electrode and atomic absorption methods have been employed to obtain information on the complex forming properties of fulvic acid with iron and calcium. A model for interpreting complexation of metal ions to fulvic acid at any pH, medium ionic strength and metal to fulvic acid ratio developed earlier has been used in an attempt to predict the nature of iron and calcium interaction to Armadale Horizon Bh fulvic acid. Binding of calcium to fulvic acid which is enhanced at pHs greater than 6.0 has reasonably been predicted by the model taking into consideration complications due to the polyelectrolyte nature and the heterogeneity of the fulvic acid. The lack of agreement observed between the model predicted binding behavior and the experimentally observed results for the fulvic acid-iron system has been attributed to the formation of metal-induced aggregation. Reduction of Fe(III) to Fe(II) by the fulvic acid as reported by other workers is corroborated. (orig.)

  11. THE NATURE OF Lyα BLOBS: POWERED BY EXTREME STARBURSTS

    International Nuclear Information System (INIS)

    Cen, Renyue; Zheng, Zheng

    2013-01-01

    We present a new model for the observed Lyα blobs (LABs) within the context of the standard cold dark matter model. In this model, LABs are the most massive halos with the strongest clustering (protoclusters) undergoing extreme starbursts in the high-z universe. Aided by calculations of detailed radiative transfer of Lyα photons through ultrahigh resolution (159 pc), large-scale (≥30 Mpc) adaptive mesh refinement cosmological hydrodynamic simulations with galaxy formation, this model is shown to be able to, for the first time, reproduce simultaneously the global Lyα luminosity function and the luminosity-size relation of the observed LABs. Physically, a combination of dust attenuation of Lyα photons within galaxies, clustering of galaxies, and the complex propagation of Lyα photons through the circumgalactic and intergalactic medium gives rise to the large sizes and the irregular isophotal shapes of LABs that are frequently observed. A generic and unique prediction of this model is that there should be strong far-infrared (FIR) sources within each LAB with the most luminous FIR source likely representing the gravitational center of the protocluster, not necessarily the apparent center of the Lyα emission of the LAB or the most luminous optical source. Upcoming ALMA observations should unambiguously test this prediction. If verified, LABs will provide very valuable laboratories for studying the formation of galaxies in the most overdense regions of the universe at a time when the global star formation was the most vigorous

  12. The Nature of Lyα Blobs: Powered by Extreme Starbursts

    Science.gov (United States)

    Cen, Renyue; Zheng, Zheng

    2013-10-01

    We present a new model for the observed Lyα blobs (LABs) within the context of the standard cold dark matter model. In this model, LABs are the most massive halos with the strongest clustering (protoclusters) undergoing extreme starbursts in the high-z universe. Aided by calculations of detailed radiative transfer of Lyα photons through ultrahigh resolution (159 pc), large-scale (>=30 Mpc) adaptive mesh refinement cosmological hydrodynamic simulations with galaxy formation, this model is shown to be able to, for the first time, reproduce simultaneously the global Lyα luminosity function and the luminosity-size relation of the observed LABs. Physically, a combination of dust attenuation of Lyα photons within galaxies, clustering of galaxies, and the complex propagation of Lyα photons through the circumgalactic and intergalactic medium gives rise to the large sizes and the irregular isophotal shapes of LABs that are frequently observed. A generic and unique prediction of this model is that there should be strong far-infrared (FIR) sources within each LAB with the most luminous FIR source likely representing the gravitational center of the protocluster, not necessarily the apparent center of the Lyα emission of the LAB or the most luminous optical source. Upcoming ALMA observations should unambiguously test this prediction. If verified, LABs will provide very valuable laboratories for studying the formation of galaxies in the most overdense regions of the universe at a time when the global star formation was the most vigorous.

  13. Generalised extreme value distributions provide a natural hypothesis for the shape of seed mass distributions.

    Directory of Open Access Journals (Sweden)

    Will Edwards

    Full Text Available Among co-occurring species, values for functionally important plant traits span orders of magnitude, are uni-modal, and generally positively skewed. Such data are usually log-transformed "for normality" but no convincing mechanistic explanation for a log-normal expectation exists. Here we propose a hypothesis for the distribution of seed masses based on generalised extreme value distributions (GEVs, a class of probability distributions used in climatology to characterise the impact of event magnitudes and frequencies; events that impose strong directional selection on biological traits. In tests involving datasets from 34 locations across the globe, GEVs described log10 seed mass distributions as well or better than conventional normalising statistics in 79% of cases, and revealed a systematic tendency for an overabundance of small seed sizes associated with low latitudes. GEVs characterise disturbance events experienced in a location to which individual species' life histories could respond, providing a natural, biological explanation for trait expression that is lacking from all previous hypotheses attempting to describe trait distributions in multispecies assemblages. We suggest that GEVs could provide a mechanistic explanation for plant trait distributions and potentially link biology and climatology under a single paradigm.

  14. Natural radioactivity in extreme south of Bahia, Brazil, using gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Vasconcelos, Danilo C.; Oliveira, Arno H.; Silva, Mario R.S.; Penna, Rodrigo; Santos, Talita O.; Pereira, Claubia; Rocha, Zildete; Menezes, Maria Angela B.C.

    2009-01-01

    The concentrations activity of natural radionuclides in beach sand in extreme south of Bahia-Brazil was measured using gamma-ray spectrometry. The activity concentrations of 226 Ra, 232 Th and 40 K in beach sand ranged from 14.5 to 8,318.4, 20.5 to 18,450.0, 15.4 to 3,109.0 Bq/kg, with a mean value of 1,078.2, 2,429.6, and 417.0 Bq/kg respectively. The values of radiation hazard indexes in sands of Alcobaca, Caraiva and Cumuruxatiba are higher than the limits preconized by Beretka and Mathew. The use of these sands may be not safe in building constructions. The results show that the absorbed dose rates range from 20.4-15,116.6 nGy/h with mean value of 1762.7. The highest value of gamma dose rates among the studied beaches was found in Cumuruxatiba (15,116.6 nGy/h). The annual effective dose varied between 0.028 and 18.539 mSv/year, with a mean of 2.162 mSv/year. Values of Alcobaca, Trancoso, Caraiva and Cumuruxatiba are higher than the worldwide average for outdoor annual effective dose, 0.07 mSv/year. (author)

  15. Extreme-Scale Bayesian Inference for Uncertainty Quantification of Complex Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Biros, George [Univ. of Texas, Austin, TX (United States)

    2018-01-12

    Uncertainty quantification (UQ)—that is, quantifying uncertainties in complex mathematical models and their large-scale computational implementations—is widely viewed as one of the outstanding challenges facing the field of CS&E over the coming decade. The EUREKA project set to address the most difficult class of UQ problems: those for which both the underlying PDE model as well as the uncertain parameters are of extreme scale. In the project we worked on these extreme-scale challenges in the following four areas: 1. Scalable parallel algorithms for sampling and characterizing the posterior distribution that exploit the structure of the underlying PDEs and parameter-to-observable map. These include structure-exploiting versions of the randomized maximum likelihood method, which aims to overcome the intractability of employing conventional MCMC methods for solving extreme-scale Bayesian inversion problems by appealing to and adapting ideas from large-scale PDE-constrained optimization, which have been very successful at exploring high-dimensional spaces. 2. Scalable parallel algorithms for construction of prior and likelihood functions based on learning methods and non-parametric density estimation. Constructing problem-specific priors remains a critical challenge in Bayesian inference, and more so in high dimensions. Another challenge is construction of likelihood functions that capture unmodeled couplings between observations and parameters. We will create parallel algorithms for non-parametric density estimation using high dimensional N-body methods and combine them with supervised learning techniques for the construction of priors and likelihood functions. 3. Bayesian inadequacy models, which augment physics models with stochastic models that represent their imperfections. The success of the Bayesian inference framework depends on the ability to represent the uncertainty due to imperfections of the mathematical model of the phenomena of interest. This is a

  16. Natural lecithin promotes neural network complexity and activity

    Science.gov (United States)

    Latifi, Shahrzad; Tamayol, Ali; Habibey, Rouhollah; Sabzevari, Reza; Kahn, Cyril; Geny, David; Eftekharpour, Eftekhar; Annabi, Nasim; Blau, Axel; Linder, Michel; Arab-Tehrany, Elmira

    2016-01-01

    Phospholipids in the brain cell membranes contain different polyunsaturated fatty acids (PUFAs), which are critical to nervous system function and structure. In particular, brain function critically depends on the uptake of the so-called “essential” fatty acids such as omega-3 (n-3) and omega-6 (n-6) PUFAs that cannot be readily synthesized by the human body. We extracted natural lecithin rich in various PUFAs from a marine source and transformed it into nanoliposomes. These nanoliposomes increased neurite outgrowth, network complexity and neural activity of cortical rat neurons in vitro. We also observed an upregulation of synapsin I (SYN1), which supports the positive role of lecithin in synaptogenesis, synaptic development and maturation. These findings suggest that lecithin nanoliposomes enhance neuronal development, which may have an impact on devising new lecithin delivery strategies for therapeutic applications. PMID:27228907

  17. Natural lecithin promotes neural network complexity and activity.

    Science.gov (United States)

    Latifi, Shahrzad; Tamayol, Ali; Habibey, Rouhollah; Sabzevari, Reza; Kahn, Cyril; Geny, David; Eftekharpour, Eftekhar; Annabi, Nasim; Blau, Axel; Linder, Michel; Arab-Tehrany, Elmira

    2016-05-27

    Phospholipids in the brain cell membranes contain different polyunsaturated fatty acids (PUFAs), which are critical to nervous system function and structure. In particular, brain function critically depends on the uptake of the so-called "essential" fatty acids such as omega-3 (n-3) and omega-6 (n-6) PUFAs that cannot be readily synthesized by the human body. We extracted natural lecithin rich in various PUFAs from a marine source and transformed it into nanoliposomes. These nanoliposomes increased neurite outgrowth, network complexity and neural activity of cortical rat neurons in vitro. We also observed an upregulation of synapsin I (SYN1), which supports the positive role of lecithin in synaptogenesis, synaptic development and maturation. These findings suggest that lecithin nanoliposomes enhance neuronal development, which may have an impact on devising new lecithin delivery strategies for therapeutic applications.

  18. Genome-reconstruction for eukaryotes from complex natural microbial communities.

    Science.gov (United States)

    West, Patrick T; Probst, Alexander J; Grigoriev, Igor V; Thomas, Brian C; Banfield, Jillian F

    2018-04-01

    Microbial eukaryotes are integral components of natural microbial communities, and their inclusion is critical for many ecosystem studies, yet the majority of published metagenome analyses ignore eukaryotes. In order to include eukaryotes in environmental studies, we propose a method to recover eukaryotic genomes from complex metagenomic samples. A key step for genome recovery is separation of eukaryotic and prokaryotic fragments. We developed a k -mer-based strategy, EukRep, for eukaryotic sequence identification and applied it to environmental samples to show that it enables genome recovery, genome completeness evaluation, and prediction of metabolic potential. We used this approach to test the effect of addition of organic carbon on a geyser-associated microbial community and detected a substantial change of the community metabolism, with selection against almost all candidate phyla bacteria and archaea and for eukaryotes. Near complete genomes were reconstructed for three fungi placed within the Eurotiomycetes and an arthropod. While carbon fixation and sulfur oxidation were important functions in the geyser community prior to carbon addition, the organic carbon-impacted community showed enrichment for secreted proteases, secreted lipases, cellulose targeting CAZymes, and methanol oxidation. We demonstrate the broader utility of EukRep by reconstructing and evaluating relatively high-quality fungal, protist, and rotifer genomes from complex environmental samples. This approach opens the way for cultivation-independent analyses of whole microbial communities. © 2018 West et al.; Published by Cold Spring Harbor Laboratory Press.

  19. "Complex" Posttraumatic Stress Disorder/Disorders of Extreme Stress (CP/DES) in Sexually Abused Children: An Exloratory Study.

    Science.gov (United States)

    Hall, Darlene Kordich

    1999-01-01

    Compares three groups of young sexually abused children on seven "Complex" Posttraumatic Stress Disorder/Disorders of Extreme Stress (CP/DES) indices. As cumulative number of types of trauma increased, the number of CP/DES symptoms rose. Results suggest that CP/DES also characterizes sexually abused children, especially those who have…

  20. Diagnosing the Nature of Land-Atmosphere Coupling: A Case Study of Dry/Wet Extremes

    Science.gov (United States)

    Santanello, Joseph A., Jr.; Peters-Lidard, Christa; Kennedy, Aaron D.

    2012-01-01

    Land-atmosphere (L-A) interactions play a critical role in determining the diurnal evolution of land surface and planetary boundary layer (PBL) temperature and moisture states and fluxes. In turn, these interactions regulate the strength of the connection between surface moisture and precipitation in a coupled system. To address deficiencies in numerical weather prediction and climate models due to improper treatment of L-A interactions, recent studies have focused on development of diagnostics to quantify the strength and accuracy of the land-PBL coupling at the process-level. In this study, a diagnosis of the nature and impacts oflocalland-atmosphere coupling (LoCo) during dry and wet extreme conditions is presented using a combination of models and observations during the summers of2006-7 in the U.S. Southern Great Plains. Specifically, the Weather Research and Forecasting (WRF) model has been coupled to NASA's Land Information System (LIS), which provides a flexible and high-resolution representation and initialization of land surface physics and states. A range of diagnostics exploring the links and feedbacks between soil moisture and precipitation are examined for the dry/wet regimes of this region, along with the behavior and accuracy of different land-PBL scheme couplings under these conditions. In addition, we examine the impact of improved specification ofland surface states, anomalies, and fluxes that are obtained through the use of a hew optimization and uncertainty module in LIS, on the L-A coupling in WRF forecasts. Results demonstrate how LoCo diagnostics can be applied to coupled model components in the context of their integrated impacts on the process-chain connecting the land surface to the PBL and support of hydrological anomalies.

  1. Blood parasites shape extreme major histocompatibility complex diversity in a migratory passerine.

    Science.gov (United States)

    Biedrzycka, Aleksandra; Bielański, Wojciech; Ćmiel, Adam; Solarz, Wojciech; Zając, Tadeusz; Migalska, Magdalena; Sebastian, Alvaro; Westerdahl, Helena; Radwan, Jacek

    2018-06-01

    Pathogens are one of the main forces driving the evolution and maintenance of the highly polymorphic genes of the vertebrate major histocompatibility complex (MHC). Although MHC proteins are crucial in pathogen recognition, it is still poorly understood how pathogen-mediated selection promotes and maintains MHC diversity, and especially so in host species with highly duplicated MHC genes. Sedge warblers (Acrocephalus schoenobaenus) have highly duplicated MHC genes, and using data from high-throughput MHC genotyping, we were able to investigate to what extent avian malaria parasites explain temporal MHC class I supertype fluctuations in a long-term study population. We investigated infection status and infection intensities of two different strains of Haemoproteus, that is avian malaria parasites that are known to have significant fitness consequences in sedge warblers. We found that prevalence of avian malaria in carriers of specific MHC class I supertypes was a significant predictor of their frequency changes between years. This finding suggests that avian malaria infections partly drive the temporal fluctuations of the MHC class I supertypes. Furthermore, we found that individuals with a large number of different supertypes had higher resistance to avian malaria, but there was no evidence for an optimal MHC class I diversity. Thus, the two studied malaria parasite strains appear to select for a high MHC class I supertype diversity. Such selection may explain the maintenance of the extremely high number of MHC class I gene copies in sedge warblers and possibly also in other passerines where avian malaria is a common disease. © 2018 John Wiley & Sons Ltd.

  2. 48 CFR 52.246-18 - Warranty of Supplies of a Complex Nature.

    Science.gov (United States)

    2010-10-01

    ... Complex Nature. 52.246-18 Section 52.246-18 Federal Acquisition Regulations System FEDERAL ACQUISITION... Clauses 52.246-18 Warranty of Supplies of a Complex Nature. As prescribed in 46.710(b)(1), insert a clause substantially as follows: Warranty of Supplies of a Complex Nature (MAY 2001) (a) Definitions. As used in this...

  3. Public health implications of complex emergencies and natural disasters.

    Science.gov (United States)

    Culver, Amanda; Rochat, Roger; Cookson, Susan T

    2017-01-01

    During the last decade, conflict or natural disasters have displaced unprecedented numbers of persons. This leads to conditions prone to outbreaks that imperil the health of displaced persons and threaten global health security. Past literature has minimally examined the association of communicable disease outbreaks with complex emergencies (CEs) and natural disasters (NDs). To examine this association, we identified CEs and NDs using publicly available datasets from the Center for Research on the Epidemiology of Disasters and United Nations Flash and Consolidated Appeals archive for 2005-2014. We identified outbreaks from World Health Organization archives. We compared findings to identify overlap of outbreaks, including their types (whether or not of a vaccine-preventable disease), and emergency event types (CE, ND, or Both) by country and year using descriptive statistics and measure of association. There were 167 CEs, 912 NDs, 118 events linked to 'Both' types of emergencies, and 384 outbreaks. Of CEs, 43% were associated with an outbreak; 24% NDs were associated with an outbreak; and 36% of 'Both' types of emergencies were associated with an outbreak. Africa was disproportionately affected, where 67% of total CEs, 67% of 'Both' events (CE and ND), and 46% of all outbreaks occurred for the study period. The odds ratio of a vaccine-preventable outbreak occurring in a CE versus an ND was 4.14 (95% confidence limits 1.9, 9.4). CEs had greater odds of being associated with outbreaks compared with NDs. Moreover, CEs had high odds of a vaccine-preventable disease causing that outbreak. Focusing on better vaccine coverage could reduce CE-associated morbidity and mortality by preventing outbreaks from spreading.

  4. Intersubject information mapping: revealing canonical representations of complex natural stimuli

    Directory of Open Access Journals (Sweden)

    Nikolaus Kriegeskorte

    2015-03-01

    Full Text Available Real-world time-continuous stimuli such as video promise greater naturalism for studies of brain function. However, modeling the stimulus variation is challenging and introduces a bias in favor of particular descriptive dimensions. Alternatively, we can look for brain regions whose signal is correlated between subjects, essentially using one subject to model another. Intersubject correlation mapping (ICM allows us to find brain regions driven in a canonical manner across subjects by a complex natural stimulus. However, it requires a direct voxel-to-voxel match between the spatiotemporal activity patterns and is thus only sensitive to common activations sufficiently extended to match up in Talairach space (or in an alternative, e.g. cortical-surface-based, common brain space. Here we introduce the more general approach of intersubject information mapping (IIM. For each brain region, IIM determines how much information is shared between the subjects' local spatiotemporal activity patterns. We estimate the intersubject mutual information using canonical correlation analysis applied to voxels within a spherical searchlight centered on each voxel in turn. The intersubject information estimate is invariant to linear transforms including spatial rearrangement of the voxels within the searchlight. This invariance to local encoding will be crucial in exploring fine-grained brain representations, which cannot be matched up in a common space and, more fundamentally, might be unique to each individual – like fingerprints. IIM yields a continuous brain map, which reflects intersubject information in fine-grained patterns. Performed on data from functional magnetic resonance imaging (fMRI of subjects viewing the same television show, IIM and ICM both highlighted sensory representations, including primary visual and auditory cortices. However, IIM revealed additional regions in higher association cortices, namely temporal pole and orbitofrontal cortex. These

  5. Weather Impacts on Natural, Social and Economic Systems (WISE). Part 2. Individual Perception of Climate Extremes in Italy

    International Nuclear Information System (INIS)

    Galeotti, M.; Goria, A.; Spantidaki, E.; Mombrini, P.

    2004-02-01

    This paper focuses on the results of the research work carried out by Fondazione Eni Enrico Mattei (FEEM) within the WISE project. This project aims at investigating the effects and the impacts of extreme weather events, particularly very warm summers, mild winters and storms, on the socio-economic systems of European countries. The output consists of a series of empirical studies, both of quantitative and qualitative descriptive nature. The work of FEEM in the WISE project covers the quantitative analysis of the impacts of climate extremes on the socio-economic system in Italy and the analysis of individuals' perception of climate extremes based on results from individuals' surveys. In this paper is considered the study of the perception of weather impacts through questionnaire survey to the general public. With regard to the individuals' perception survey, a sample of 300 individuals were interviewed by telephone: 150 extracted from the North of Italy and 150 from the South of Italy. Individuals were asked general questions about their perception of climate extremes, and about the impacts of weather extremes on their daily habits at work, at home, in their leisure activities, on their transport patterns, on their health and tourism choices

  6. INFLUENCE OF NATURAL ADDITIVES ON PROTEIN COMPLEX OF BREAD

    Directory of Open Access Journals (Sweden)

    Dana Urminská

    2010-11-01

    Full Text Available The study focuses on researching the influence of natural additives on certain technological characteristics of mixtures used for bread production, more particularly the influence of N substances in used raw material on selected qualitative parameters of bread. The blends for bread production to be analysed were prepared by mixing wheat flour with an addition of oat, buckwheat, lentil and chickpea wholegrain flour in different portions (10, 20, 30, 40 and 50 %. The experiment showed that the addition of natural additives worsened the protein complex of the blends used in bread production (worsening also qualitative parameters known as product volume. The loaves prepared with an addition of buckwheat, oat, lentil and chickpea were evaluated to be of a lesser quality from a technological viewpoint when compared with pure wheat loaves. The lower content of gluten forming proteins and the generally changed protein composition of blends due to additives caused a lower percentage of wet gluten content, its lower extensibility and swelling capacity. The sedimentation value (Zeleny index decreased proportionally with the increase of addition until the level was unsatisfactory for raw material intended for bakery purposes. The N content in experimental loaves was higher than in the reference loaves and it increased according to the selected additive and its portion in the blend (more with the addition of lentil and chickpea, less in case of buckwheat and oat which is considered as positive from a nutritional point of view. But from the technological point of view the additives did not show any positive influence and caused a lower loaf bread volume. The most significant decrease of the loaf bread volume was found with the addition of 50 % of buckwheat (- 45.6 %. Better results were obtained with a lower portion of the additive: loaf with an addition of 30 % of chickpea (volume decreased by 12.8 % > loaf with an addition of 30 % of lentil (volume

  7. How nature works complexity in interdisciplinary research and applications

    CERN Document Server

    Sanayei, Ali; Zenil, Hector; Rössler, Otto

    2014-01-01

    This book is based on the outcome of the “2012 Interdisciplinary Symposium on Complex Systems” held at the island of Kos.  The book consists of 12 selected papers of the symposium starting with a comprehensive overview and classification of complexity problems, continuing by chapters about complexity, its observation, modeling and its applications to solving various problems including real-life applications. More exactly, readers will have an encounter with the structural complexity of vortex flows, the use of chaotic dynamics within evolutionary algorithms, complexity in synthetic biology, types of complexity hidden inside evolutionary dynamics and possible controlling methods, complexity of rugged landscapes, and more. All selected papers represent innovative ideas, philosophical overviews and state-of-the-art discussions on aspects of complexity.  The book will be useful as instructional material for senior undergraduate and entry-level graduate students in computer science, physics, applied mathemat...

  8. Low complexity iterative MLSE equalization of M-QAM signals in extremely long rayleigh fading channels

    CSIR Research Space (South Africa)

    Myburgh, HC

    2009-05-01

    Full Text Available long channels. Its computational complexity is linear in the data block length and approximately independent of the channel memory length, whereas conventional equalization algorithms have computational complexity linear in the data block length...

  9. Wetlands and Flood Mitigation in Ontario: Natural adaptation to extreme rainfall

    OpenAIRE

    Marchildon, Mason

    2017-01-01

    Abstract Wetlands are often recognized for their flood control value, but little research exists specific to Ontario, where extreme weather causing flooding poses ever-greater threats to urban areas. Ducks Unlimited Canada has undertaken new research to better understand the role of wetlands in storing and attenuating flood flows in an urban/rural watershed. The second phase of this research, reported here, employs advanced hydrologic modelling to address the questions of where and how we...

  10. Drop amalgam voltammetric study of lead complexation by natural ...

    African Journals Online (AJOL)

    A study of inorganic complexation of lead using drop amalgam voltammetry is described. The study has been carried out in simulated salt lake water and at ionic strength of 7.35 M, the predetermined ionic strength of Lake Katwe. The complexation of lead with the simple ligands (Cl-, CO32-) created anodic waves and the ...

  11. Humanism and nature – some reflections on a complex relationship

    Directory of Open Access Journals (Sweden)

    Jörn Rüsen

    2006-04-01

    Full Text Available The paper starts with a systematical analysis of the interrelationship of humanism and nature. It proceeds to a historical reconstruction of this relationship in the development of Western humanism from ancient Rome via Renaissance till the Enlightenment of the 18th century. In both respects the result of the analysis is the same: The Western tradition of humanism is characterised by a gap between an emphasis on the cultural quality of human life on the one hand and nature on the other one. Men are entitled to dominate and govern nature and use it for their purpose. This fits into an idea of a progressing destructive relationship between man and nature in the West. On the other the tradition of humanism has put the gap between man and nature into a harmonising cosmological or theological context. In this context a simple destructive relationship between man and nature is not possible. The humanism of today has to pick up the challenge of the ecological crisis and to refer to its tradition where man and nature are mediated into a meaningful and sense-bearing interrelationship. Instead of simply referring to the traditional cosmology a convincing idea of this mediation or even synthesis can only be made plausible by referring to the already pre-given synthesis between nature and culture, the human body.

  12. Case study: Rainfall partitioning across a natural-to-urban forest gradient during an extreme rain event

    Science.gov (United States)

    Akin, B. H.; Van Stan, J. T., II; Cote, J. F.; Jarvis, M. T.; Underwood, J.; Friesen, J.; Hildebrandt, A.; Maldonado, G.

    2017-12-01

    Trees' partitioning of rainfall is an important first process along the rainfall-to-runoff pathway that has economically significant influences on urban stormwater management. However, important knowledge gaps exist regarding (1) its role during extreme storms and (2) how this role changes as forest structure is altered by urbanization. Little research has been conducted on canopy rainfall partitioning during large, intense storms, likely because canopy water storage is rapidly overwhelmed (i.e., 1-3 mm) by short duration events exceeding, for example, 80 mm of rainfall. However, canopy structure controls more than just storage; it also affects the time for rain to drain to the surface (becoming throughfall) and the micrometeorological conditions that drive wet canopy evaporation. In fact, observations from an example extreme ( 100 mm with maximum 5-minute intensities exceeding 55 mm/h) storm across a urban-to-natural gradient in pine forests in southeast Georgia (USA), show that storm intensities were differentially dampened by 33% (tree row), 28% (forest fragment), and 17% (natural forests). In addition, maximum wet canopy evaporation rates were higher for the exposed tree row (0.18 mm/h) than for the partially-enclosed fragment canopy (0.14 mm/h) and the closed canopy natural forest site (0.11). This resulted in interception percentages decreasing from urban-to-natural stand structures (25% to 16%). A synoptic analysis of the extreme storm in this case study also shows that the mesoscale meteorological conditions that developed the heavy rainfall is expected to occur more often with projected climate changes.

  13. Complex Socio-Ecological Dynamics driven by extreme events in the Amazon

    Science.gov (United States)

    Pinho, P. F.

    2015-12-01

    Several years with extreme floods or droughts in the past decade have caused human suffering in remote communities of the Brazilian Amazon. Despite documented local knowledge and practices for coping with the high seasonal variability characteristic of the region's hydrology (e.g. 10m change in river levels between dry and flood seasons), and despite 'civil Defense' interventions by various levels of government, the more extreme years seem to have exceeded the coping capacity of the community. In this paper, we explore whether there is a real increase in variability, whether the community perceives that recent extreme events are outside the experience which shapes their responses to 'normal' levels of variability, and what science-based policy could contribute to greater local resilience. Hydrological analyses suggest that variability is indeed increasing, in line with expectations from future climate change. However, current measures of hydrological regimes do not predict years with social hardship very well. Interviewees in two regions are able to express their strategies for dealing with 'normal' variability very well, but also identify ways in which abnormal years exceed their ability to cope. Current Civil Defense arrangements struggle to deliver emergency assistance in a sufficiently timely and locally appropriate fashion. Combining these insights in the context of social-ecological change, we suggest how better integration of science, policy and local knowledge could improve resilience to future trends, and identify some contributions science could make into such an arrangement.

  14. The Chameleonic Nature of Platinum(II) Imidazopyridine Complexes.

    Science.gov (United States)

    Pinter, Piermaria; Pittkowski, Rebecca; Soellner, Johannes; Strassner, Thomas

    2017-10-12

    The synthesis and characterization of cyclometalated C^C* platinum(II) complexes with unique photophysical properties, aggregation induced enhancement of the quantum yields with a simultaneous decrease of phosphorescence lifetimes, is reported. Additionally, a change of emission color is induced by variation of the excitation wavelength. The aggregation behavior of these complexes is controlled by the steric demand of the substituents. The photophysical properties of these complexes are investigated through emission-excitation matrix analysis (EEM). The monomeric complexes are excellent room temperature phosphorescent blue emitters with emission maxima below 470 nm and quantum yields of up to 93 %. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Generating and Executing Complex Natural Language Queries across Linked Data.

    Science.gov (United States)

    Hamon, Thierry; Mougin, Fleur; Grabar, Natalia

    2015-01-01

    With the recent and intensive research in the biomedical area, the knowledge accumulated is disseminated through various knowledge bases. Links between these knowledge bases are needed in order to use them jointly. Linked Data, SPARQL language, and interfaces in Natural Language question-answering provide interesting solutions for querying such knowledge bases. We propose a method for translating natural language questions in SPARQL queries. We use Natural Language Processing tools, semantic resources, and the RDF triples description. The method is designed on 50 questions over 3 biomedical knowledge bases, and evaluated on 27 questions. It achieves 0.78 F-measure on the test set. The method for translating natural language questions into SPARQL queries is implemented as Perl module available at http://search.cpan.org/ thhamon/RDF-NLP-SPARQLQuery.

  16. The analysis on the extreme water shortage event in Hangzhou in 1247 AD and its natural and social backgrounds

    Science.gov (United States)

    Liu, Haolong

    2017-04-01

    Yangtze River Delta locating in the north subtropics of China, is famous for numerous rivers and lakes. Because of East Asian monsoon rainfall, flood is always the most primary disaster in this area during the past 2000 years. However, there were also several extreme water shortage events in the history. Example in Hangzhou in 1247 AD was such a typical year in the area. In the paper, the severity of this extreme event and the closely tied spatiotemporal variation of drought in Yangtze River Delta was quantitatively analyzed on the basis of documentary records during Southern Song Dynasty. Furtherly, its natural and social backgrounds was discussed. The result s are summarized as follows: 1) Wells, canals and West Lake of Hangzhou dried up in 1247 AD. The water level of canals was about 1.32-2.64 m lower than that in the normal year. The reduction of storage capacity in West Lake was 21 million stere or so. 2) The droughts in Yangtze River Delta was moderate on the whole, but that in the west of Zhejiang Province was severe. The drought in Hangzhou lasted from the 2nd lunar month to the end of this year. 3) The water shortage event was closely related to the quick going north and farther northern location of summer rain belt. The descending sea-level weakening the tide in Qiantang River, can also reduce the supply of water resources. 4) The quick growth of urban population, excessive aquaculture, and ineffective government supervision played an important social role in the process of this event. In the all, this extreme water shortage event was the result of both natural and social factors. This research is very helpful for the futuristic water resource forecast in Yangtze River Delta, and it also affords us lessons on the risk management and heritage conservation that merit attention. Key Words: Hangzhou, 1247 AD, water shortage, canal, West Lake, natural factors, social factors

  17. Complex networks: Effect of subtle changes in nature of randomness

    Science.gov (United States)

    Goswami, Sanchari; Biswas, Soham; Sen, Parongama

    2011-03-01

    In two different classes of network models, namely, the Watts Strogatz type and the Euclidean type, subtle changes have been introduced in the randomness. In the Watts Strogatz type network, rewiring has been done in different ways and although the qualitative results remain the same, finite differences in the exponents are observed. In the Euclidean type networks, where at least one finite phase transition occurs, two models differing in a similar way have been considered. The results show a possible shift in one of the phase transition points but no change in the values of the exponents. The WS and Euclidean type models are equivalent for extreme values of the parameters; we compare their behaviour for intermediate values.

  18. Catastrophes in nature and society mathematical modeling of complex systems

    CERN Document Server

    Khlebopros, Rem G; Fet, Abram I

    2007-01-01

    Many people are concerned about crises leading to disasters in nature, in social and economic life. The book offers a popular account of the causative mechanisms of critical states and breakdown in a broad range of natural and cultural systems - which obey the same laws - and thus makes the reader aware of the origin of catastrophic events and the ways to avoid and mitigate their negative consequences. The authors apply a single mathematical approach to investigate the revolt of cancer cells that destroy living organisms and population outbreaks that upset natural ecosystems, the balance between biosphere and global climate interfered lately by industry, the driving mechanisms of market and related economic and social phenomena, as well as the electoral system the proper use of which is an arduous accomplishment of democracy.

  19. Bunched black (and grouped grey) swans: Dissipative and non-dissipative models of correlated extreme fluctuations in complex geosystems

    Science.gov (United States)

    Watkins, N. W.

    2013-01-01

    I review the hierarchy of approaches to complex systems, focusing particularly on stochastic equations. I discuss how the main models advocated by the late Benoit Mandelbrot fit into this classification, and how they continue to contribute to cross-disciplinary approaches to the increasingly important problems of correlated extreme events and unresolved scales. The ideas have broad importance, with applications ranging across science areas as diverse as the heavy tailed distributions of intense rainfall in hydrology, after which Mandelbrot named the "Noah effect"; the problem of correlated runs of dry summers in climate, after which the "Joseph effect" was named; and the intermittent, bursty, volatility seen in finance and fluid turbulence.

  20. Binary Molecular Complexes and the Nature of Molecular Association

    African Journals Online (AJOL)

    NJD

    2004-06-15

    Jun 15, 2004 ... their values in the non-interacting monomer.20 We have selected as examples of hydrogen-bonded complexes for study those formed between methanol as proton donor and trimethylamine, dimethyl ether, methyl fluoride, trimethyl phosphine, dimethyl sulphide and methyl chloride as proton acceptors.

  1. Taxol: A complex diterpenoid natural product with an evolutionarily ...

    African Journals Online (AJOL)

    In addition to Taxus sp, taxoids are also synthesized by various endophytic fungi, which often live in association with Taxus trees, thus raising questions about the evolutionary origin of this complex diterpenoid pathway. In the future, it may be possible to improve taxoid synthesis through the genetic modification of Taxus cell ...

  2. Transformation of natural complexes, conservation of biodiversity and ecological management of the Polessky radio-ecological nature reserve territory

    International Nuclear Information System (INIS)

    Maslovskij, O.M.; Rykovskij, G.F.

    2001-01-01

    Investigation of mechanisms of radionuclide contamination influence on natural complexes after the Chernobyl diaster showed that the contamination level is not dangerous for the majority of plant and animal species within the larger part of 30km zone and outside it. Medical aspects are discussed in another article. The nature as a whole has coped with the negative influence of the Chernobyl disaster. At the same time natural complexes of the Polessky State Radio-Ecological Nature Reserve (PSRENR) have transformed after the removal of antropogenic stress. Different succession changes take place, biodivesity has sharply increased. It allows us to consider this territory as one of the most important nature protection objects nor only in Belarus but also in East Europe

  3. Photochemical Approaches to Complex Chemotypes: Applications in Natural Product Synthesis

    Science.gov (United States)

    2016-01-01

    The use of photochemical transformations is a powerful strategy that allows for the formation of a high degree of molecular complexity from relatively simple building blocks in a single step. A central feature of all light-promoted transformations is the involvement of electronically excited states, generated upon absorption of photons. This produces transient reactive intermediates and significantly alters the reactivity of a chemical compound. The input of energy provided by light thus offers a means to produce strained and unique target compounds that cannot be assembled using thermal protocols. This review aims at highlighting photochemical transformations as a tool for rapidly accessing structurally and stereochemically diverse scaffolds. Synthetic designs based on photochemical transformations have the potential to afford complex polycyclic carbon skeletons with impressive efficiency, which are of high value in total synthesis. PMID:27120289

  4. Clathrin-independent endocytosis: from nonexisting to an extreme degree of complexity

    DEFF Research Database (Denmark)

    Sandvig, Kirsten; Torgersen, Maria Lyngaas; Raa, Hilde Andersen

    2008-01-01

    Today it is generally accepted that there are several endocytic mechanisms, both the clathrin-dependent one and mechanisms which operate without clathrin and with different requirements when it comes to dynamin, small GTP-binding proteins of the Rho family and specific lipids. It should be noted ...... to give an overview of the complexity of the mechanisms and their regulation....

  5. Complex magnetic susceptibility setup for spectroscopy in the extremely low-frequency range

    NARCIS (Netherlands)

    Kuipers, B.W.M.; Bakelaar, I.A.; Klokkenburg, M.; Erne, B.H.

    2008-01-01

    A sensitive balanced differential transformer was built to measure complex initial parallel magnetic susceptibility spectra in the 0.01–1000 Hz range. The alternating magnetic field can be chosen sufficiently weak that the magnetic structure of the samples is only slightly perturbed and the low

  6. Complex forming properties of natural occurring fulvic acids

    International Nuclear Information System (INIS)

    Marinsky, J.A.; Mathuthu, A.; Bicking, M.; Ephraim, J.

    1985-07-01

    The experimental program developed in our earlier investigations of the protonation equilibria encountered with Armadale Horizons Bh and Suwannee River fulvic-acid has been employed in the present investigation of a Swedish fulvic acid source. Complications introduced by the polyelectrolyte nature and the degree of heterogeneity in the functional unit content of this natural organic acid molecule have been resolved as they were with the previous fulvic acid samples. The physical chemical properties of this fulvic acid have been compared with those resolved for the Armadale Horizons Bh and the Suwannee River fulvic acid as well. The insight gained from these protonation studies and metal ion binding studies, also carried out in the course of this investigation, has led to the development of a model for interpretation of the binding of metal ions to fulvic acid at any fulvic acid concentration level. With 12 refs. (Author)

  7. Peculiarities of natural convective heat removal from complex pools

    International Nuclear Information System (INIS)

    Groetzbach, Guenther

    2002-01-01

    Considerable sensitivities are investigated in using natural convection for cooling large pools. Such a flow occurred in a sump cooling concept for a water cooled reactor. The related SUCOS model experiments were analyzed by means of the FLUTAN code. The numerical interpretations show, the natural convection in large pools is strongly influenced by local thermal disturbances, either due to structures in the fluid domain, or by bounding structures interacting thermally with the fluid. These experiment specific disturbances must be recorded in the numerical model in order to achieve adequate simulations of the heat transport. Some geometric imperfections of horizontal coolers or heaters could also have tremendous influences. As a consequence, not only the numerical model has to record all relevant phenomena as realistic as possible, but also the model experiment. (author)

  8. Intrathecal Bupivacaine Monotherapy with a Retrograde Catheter for the Management of Complex Regional Pain Syndrome of the Lower Extremity.

    Science.gov (United States)

    McRoberts, W Porter; Apostol, Catalina; Haleem, Abdul

    2016-01-01

    Complex regional pain syndrome (CRPS) presents a therapeutic challenge due to its many presentations and multifaceted pathophysiology. There is no approved treatment algorithm and clinical interventions are often applied empirically. In cases of CRPS where symptoms are localized to an extremity, a targeted treatment is indicated. We describe the use of intrathecal bupivacaine monotherapy, delivered through a retrograde catheter, in the treatment of CRPS affecting the lower extremity. The patient, a 57-year-old woman with a history of failed foot surgery, was seen in our office after 2 years of ineffective treatments with local blocks and neurolytic procedures. We advanced therapy to moderately invasive procedures with an emphasis on neuromodulation. A combined central and peripheral stimulation technique that initially provided 75% pain relief, failed to provide lasting analgesia. We proceeded with an intrathecal pump implant. Based on the results of dorsal root ganglion (DRG) mapping, L5-S1 was identified as the optimal target for therapy and a retrograde catheter was placed at this level. Various intrathecal medications were tested individually. An intrathecal morphine trial was ineffective (visual analog scale [VAS] 7), while intrathecal clonidine provided excellent pain relief (VAS 0) that was limited by severe side effects. Bupivacaine provided 100% analgesia with tolerable side effects (lower extremity weakness and minor bladder incontinence) and was selected for intrathecal infusion. After 14 months, bupivacaine treatment continued to control pain exacerbations. We conclude that CRPS patients benefit from early identification of the predominant underlying symptoms and a targeted treatment with moderately invasive techniques when less invasive techniques fail. Intrathecal bupivacaine, bupivacaine monotherapy, retrograde catheter, complex regional pain syndrome (CRPS), dual stimulation, dosal root ganglion (DRG) testing.

  9. Lower extremity fatigue increases complexity of postural control during a single-legged stance

    Directory of Open Access Journals (Sweden)

    Bailey Jerry J

    2011-08-01

    Full Text Available Abstract Background Non-linear approaches to assessment of postural control can provide insight that compliment linear approaches. Control entropy (CE is a recently developed statistical tool from non-linear dynamical systems used to assess the complexity of non-stationary signals. We have previously used CE of high resolution accelerometry in running to show decreased complexity with exhaustive exercise. The purpose of this study was to determine if complexity of postural control decreases following fatiguing exercise using CE. Methods Ten subjects (5 M/5 F; 25 ± 3 yr; 169.4 ± 11.7 cm; 79.0 ± 16.9 kg consented to participation approved by Western Oregon University IRB and completed two trials separated by 2-7 days. Trials consisted of two single-legged balance tests separated by two Wingate anaerobic tests (WAnT; PreFat/PostFat, or rest period (PreRest/PostRest. Balance tests consisted of a series of five single-legged stances, separated by 30 s rest, performed while standing on the dominant leg for 15-s with the participant crossing the arms over the chest and flexing the non-dominant knee to 90 degrees. High resolution accelerometers (HRA were fixed superficial to L3/L4 at the approximate center of mass (COM. Triaxial signals from the HRA were streamed in real time at 625 Hz. COM accelerations were recorded in g's for vertical (VT, medial/lateral (ML, and anterior/posterior (AP axes. A newly developed statistic (R-test was applied to group response shapes generated by Karhunen Loeve (KL transform modes resulting from Control Entropy (CE analysis. Results R-tests showed a significant mean vector difference (p p p p Conclusions These data indicate that fatiguing exercise eliminates the differential complexity response between axes, but increases complexity in all axes compared to the non-fatigued condition. This has implications with regard to the effects of fatigue on strategies of the control system to maintain postural control.

  10. Extreme temperatures increase the deleterious consequences of inbreeding under laboratory and semi-natural conditions

    DEFF Research Database (Denmark)

    Kristensen, Torsten Nygård; Barker, J. Stuart F.; Pedersen, Kamilla Sofie

    2008-01-01

    when compared with non-inbred lines of Drosophila melanogaster under different temperature conditions. Egg-to-adult viability, developmental time and sex ratio of emerging adults are studied under low, intermediate and high temperatures under laboratory as well as semi-natural conditions. The results...... show inbreeding depression for egg-to-adult viability. The level of inbreeding depression is highly dependent on test temperature and is observed only at low and high temperatures. Inbreeding did not affect the developmental time or the sex ratio of emerging adults. However, temperature affected...... the sex ratio with more females relative to males emerging at low temperatures, suggesting that selection against males in pre-adult life stages is stronger at low temperatures. The coefficient of variation (CV) of egg-to-adult viability within and among lines is higher for inbred flies and generally...

  11. NATO Advanced Research Workshop on Extreme Man-Made and Natural Hazards in Dynamics of Structures

    CERN Document Server

    Ibrahimbegovic, Adnan

    2007-01-01

    The book provides a critical assessment of the current knowledge and indicates new challenges which are brought about at present times by fighting man-made and natural hazards in transient analysis of structures. The latter concerns both permanently fixed structures, such as those built to protect people and/or sensitive storage material (e.g. military installations) or special structures found in transportation systems (e.g. bridges, tunnels), and moving structures (such as trains, planes, ships or cars). The present threat of terrorist attacks or accidental explosions, the climate change which brings strong stormy winds or even the destructive earthquake motion that occurs in previously inactive regions or brings about tsunamis, are a few examples of the kind of applications addressed in this work. Problems of such diversity cannot be placed within a single traditional scientific discipline, but call for the expertise in probability theory for quantifying the cause, interaction problems for better understan...

  12. The Complexity of Bioactive Natural Products in Plants

    DEFF Research Database (Denmark)

    Frisch, Tina

    Plants produce a diverse range of bioactive natural products promoting their fitness. These specialized metabolites may serve as chemical defence against herbivores and pathogens and may inhibit the growth and development of competing species. Hydroxynitrile glucosides and glucosinolates are two...... classes of defence compounds, which have diverging properties, but also share common biosynthetic features. Hydroxynitrile glucosides are produced in species across the plant kingdom, whereas glucosinolates are found almost exclusively within the Brassicales, which generally does not contain...... hydroxynitrile glucosides. This division has raised questions regarding possible evolutionary relationships between the biosynthetic pathways. The very rare co-occurrence of hydroxynitrile glucosides and glucosinolates found in Alliaria petiolata (garlic mustard, løgkarse) and Carica papaya (papaya) makes...

  13. Pest control of aphids depends on landscape complexity and natural enemy interactions.

    Science.gov (United States)

    Martin, Emily A; Reineking, Björn; Seo, Bumsuk; Steffan-Dewenter, Ingolf

    2015-01-01

    Aphids are a major concern in agricultural crops worldwide, and control by natural enemies is an essential component of the ecological intensification of agriculture. Although the complexity of agricultural landscapes is known to influence natural enemies of pests, few studies have measured the degree of pest control by different enemy guilds across gradients in landscape complexity. Here, we use multiple natural-enemy exclosures replicated in 18 fields across a gradient in landscape complexity to investigate (1) the strength of natural pest control across landscapes, measured as the difference between pest pressure in the presence and in the absence of natural enemies; (2) the differential contributions of natural enemy guilds to pest control, and the nature of their interactions across landscapes. We show that natural pest control of aphids increased up to six-fold from simple to complex landscapes. In the absence of pest control, aphid population growth was higher in complex than simple landscapes, but was reduced by natural enemies to similar growth rates across all landscapes. The effects of enemy guilds were landscape-dependent. Particularly in complex landscapes, total pest control was supplied by the combined contribution of flying insects and ground-dwellers. Birds had little overall impact on aphid control. Despite evidence for intraguild predation of flying insects by ground-dwellers and birds, the overall effect of enemy guilds on aphid control was complementary. Understanding pest control services at large spatial scales is critical to increase the success of ecological intensification schemes. Our results suggest that, where aphids are the main pest of concern, interactions between natural enemies are largely complementary and lead to a strongly positive effect of landscape complexity on pest control. Increasing the availability of seminatural habitats in agricultural landscapes may thus benefit not only natural enemies, but also the effectiveness of

  14. Complex regional pain syndrome type I in the upper extremity - how efficient physical therapy and rehabilitation are.

    Science.gov (United States)

    Zečević Luković, Tanja; Ristić, Branko; Jovanović, Zorica; Rančić, Nemanja; Ignjatović Ristić, Dragana; Cuković, Saša

    2012-08-01

    To evaluate the effects of early started combined therapy in Complex Regional Pain Syndrome-1 (CRPS-1) on the upper extremities. The study included 36 patients in the first stadium of CRPS-1 on the upper extremities The mean age of patients was 42.6±14.6, the majority of them (26 of 36) were females. The right side of the upper extremity was affected much more then the left side. They were treated by combined therapy including analgetics, electrotherapy, magneto therapy and kinesitherapy. The average length of observation was 172.1 days (from 90 to 250 days). The average length of treatment was 91.5±42.16 days. Intensity of pain, swelling of the extremity, the change in skin coloration and cutaneous manifestations were assessed three times, at the beginning of the treatment, after 6 weeks and at the end of the treatment. The pain was registered in all patients at visit 1 (average pain intensity was 5.70 ±1.44 on 100 mm visual analogue scale), and it was progressively decreased during the treatment from 3.60±1.22 at the second visit to 0.34±0.68 at the third visit. Vasodilatation was registered in 30 (83.33%) patients and skin temperature asymmetries was found in 21 (58.33%) patients. The difference of size was detected in 30 (83.33%) patients at the first visit compared to four (11.11%) patients at the end of the treatment. There were six (16.66%) patients without swelling at the beginning compared to 26 (72.22%) at the end of the treatment (p less than 0.000). Complete healing was achieved in 32 patients (88.88%). The carefully chosen physical agents in combination with analgesic and non-steroidal anti-inflammatory drugs may benefit in patients with CRPS-1 on the upper extremity if the treatment starts as soon as possible.

  15. Risk-based consequences of extreme natural hazard processes in mountain regions - Multi-hazard analysis in Tyrol (Austria)

    Science.gov (United States)

    Huttenlau, Matthias; Stötter, Johann

    2010-05-01

    weighting within the risk concept, this has sufficient implications on the results of risk analyses. Thus, an equal and scale appropriated balance of those risk components is a fundamental key factor for effective natural hazard risk analyses. The results of such analyses inform especially decision makers in the insurance industry, the administration, and politicians on potential consequences and are the basis for appropriate risk management strategies. Thereby, results (i) on an annual or probabilistic risk comprehension have to be distinguished from (ii) scenario-based analyses. The first analyses are based on statistics of periodically or episodically occurring events whereas the latter approach is especially applied for extreme, non-linear, stochastic events. Focusing on the needs especially of insurance companies, the first approaches are appropriate for premium pricing and reinsurance strategies with an annual perspective, whereas the latter is focusing on events with extreme loss burdens under worst-case criteria to guarantee accordant reinsurance coverage. Moreover, the demand of adequate loss model approaches and methods is strengthened by the risk-based requirements of the upcoming capital requirement directive Solvency II. The present study estimates the potential elements at risk, their corresponding damage potentials and the Probable Maximum Losses (PMLs) of extreme natural hazards events in Tyrol (Austria) and considers adequatly the scale dependency and balanced application of the introduced risk components. Beside the introduced analysis an additionally portfolio analysis of a regional insurance company was executed. The geocoded insurance contracts of this portfolio analysis were the basis to estimate spatial, socio-economical and functional differentiated mean insurance values for the different risk categories of (i) buildings, (ii) contents or inventory, (iii) vehicles, and (iv) persons in the study area. The estimated mean insurance values were

  16. Complex networks with scale-free nature and hierarchical modularity

    Science.gov (United States)

    Shekatkar, Snehal M.; Ambika, G.

    2015-09-01

    Generative mechanisms which lead to empirically observed structure of networked systems from diverse fields like biology, technology and social sciences form a very important part of study of complex networks. The structure of many networked systems like biological cell, human society and World Wide Web markedly deviate from that of completely random networks indicating the presence of underlying processes. Often the main process involved in their evolution is the addition of links between existing nodes having a common neighbor. In this context we introduce an important property of the nodes, which we call mediating capacity, that is generic to many networks. This capacity decreases rapidly with increase in degree, making hubs weak mediators of the process. We show that this property of nodes provides an explanation for the simultaneous occurrence of the observed scale-free structure and hierarchical modularity in many networked systems. This also explains the high clustering and small-path length seen in real networks as well as non-zero degree-correlations. Our study also provides insight into the local process which ultimately leads to emergence of preferential attachment and hence is also important in understanding robustness and control of real networks as well as processes happening on real networks.

  17. Microbial arms race: Ballistic "nematocysts" in dinoflagellates represent a new extreme in organelle complexity.

    Science.gov (United States)

    Gavelis, Gregory S; Wakeman, Kevin C; Tillmann, Urban; Ripken, Christina; Mitarai, Satoshi; Herranz, Maria; Özbek, Suat; Holstein, Thomas; Keeling, Patrick J; Leander, Brian S

    2017-03-01

    We examine the origin of harpoon-like secretory organelles (nematocysts) in dinoflagellate protists. These ballistic organelles have been hypothesized to be homologous to similarly complex structures in animals (cnidarians); but we show, using structural, functional, and phylogenomic data, that nematocysts evolved independently in both lineages. We also recorded the first high-resolution videos of nematocyst discharge in dinoflagellates. Unexpectedly, our data suggest that different types of dinoflagellate nematocysts use two fundamentally different types of ballistic mechanisms: one type relies on a single pressurized capsule for propulsion, whereas the other type launches 11 to 15 projectiles from an arrangement similar to a Gatling gun. Despite their radical structural differences, these nematocysts share a single origin within dinoflagellates and both potentially use a contraction-based mechanism to generate ballistic force. The diversity of traits in dinoflagellate nematocysts demonstrates a stepwise route by which simple secretory structures diversified to yield elaborate subcellular weaponry.

  18. Solvable model with an extreme AGP ground state: relationships among fermion pairs, pairons, and natural spin geminals

    International Nuclear Information System (INIS)

    Larson, E.G.

    1986-01-01

    A model many-fermion Hamiltonian is presented for which the ground state is asymptotically an Antisymmetrized Geminal Powers (AGP) wave function with largest possible greatest eigenvalue for its two-particle reduced density matrix. Closed analytical expressions and plane-wave expansions are presented for the generating geminal of the AGP ground state and for its one-particle reduced density matrix. The natural orbitals for this generating geminal are plane waves. The generating geminal shows intensely local character in its intracule and corresponds to the formation of a quasi-boson from two fermions. One may appropriately modify this generating geminal to introduce zero occupation numbers of its one-particle reduced density matrix and to make all the nonzero occupation numbers of its one-particle reduced density matrix equal, thus making this geminal a generator of an extreme AGP wave function, with an extreme large eigenvalue for its two-particle reduced density matrix. Closed analytical expressions are also given for this modified geminal and for its one-particle reduced density matrix. The similarities and differences of the features of this model and the accepted models of the superconducting ground state of electrons in metals, and the superfluid ground state of liquid He 4 are mentioned

  19. The nature of water within bacterial spores: protecting life in extreme environments

    Science.gov (United States)

    Rice, Charles V.; Friedline, Anthony; Johnson, Karen; Zachariah, Malcolm M.; Thomas, Kieth J., III

    2011-10-01

    The bacterial spore is a formidable container of life, protecting the vital contents from chemical attack, antimicrobial agents, heat damage, UV light degradation, and water dehydration. The exact role of the spore components remains in dispute. Nevertheless, water molecules are important in each of these processes. The physical state of water within the bacterial spore has been investigated since the early 1930's. The water is found two states, free or bound, in two different areas, core and non-core. It is established that free water is accessible to diffuse and exchange with deuterated water and that the diffusible water can access all areas of the spore. The presence of bound water has come under recent scrutiny and has been suggested the water within the core is mobile, rather than bound, based on the analysis of deuterium relaxation rates. Using an alternate method, deuterium quadrupole-echo spectroscopy, we are able to distinguish between mobile and immobile water molecules. In the absence of rapid motion, the deuterium spectrum of D2O is dominated by a broad line, whose line shape is used as a characteristic descriptor of molecular motion. The deuterium spectrum of bacterial spores reveals three distinct features: the broad peak of immobilized water, a narrow line of water in rapid motion, and a signal of intermediate width. This third signal is assigned this peak from partially deuterated proteins with the spore in which N-H groups have undergone exchange with water deuterons to form N-D species. As a result of these observations, the nature of water within the spore requires additional explanation to understand how the spore and its water preserve life.

  20. The prevalence and natural history of complex sleep apnea.

    Science.gov (United States)

    Javaheri, Shahrokh; Smith, Jason; Chung, Eugene

    2009-06-15

    Central sleep apnea (CSA) may occasionally occur in patients with obstructive sleep apnea during titration with a continuous positive airway pressure (CPAP) device. To determine the prevalence and the natural history of CPAP-emergent CSA. This is a retrospective study of 1286 patients with a diagnosis of OSAwho underwent titration with a positive airway device during a 1-year period. Patients were seen in consultation and underwent full-night attended polysomnography followed by full-night attended CPAP titration. Four weeks after CPAP therapy, patients returned to the clinic for follow-up, and objective adherence to CPAP was recorded. In patients who had CSA on CPAP, a second full-night attended CPAP titration was recommended. Eighty-four of the 1286 patients developed a central apnea index (CAI) of 5 or greater per hour while on CPAP. The incidence of CSA varied from 3% to 10% monthly, with an overall incidence of 6.5%. Forty-two of the 84 patients returned for a second CPAP titration. In 33 patients, CSA was eliminated. In each of the remaining 9 patients, the CAI remained at 5 or greater per hour, with an average of 13 per hour. These patients characteristically had the most severe OSA, and 5 had a CAI of 5 or more per hour at baseline. Two of the 9 patients were on opioids In this large retrospective study of 1286 patients with a diagnosis of OSA, 6.5% had CPAP-emergent or persistent CSA. However, CPAP-emergent CSA was generally transitory and was eliminated within 8 weeks after CPAP therapy. The prevalence of CPAP-persistent CSA was about 1.5%. Severity of OSA, a CAI of 5 or greater per hour, and use of opioids were potential risk factors.

  1. Lichensphere: a protected natural microhabitat of the non-lichenised fungal communities living in extreme environments of Antarctica.

    Science.gov (United States)

    Santiago, Iara F; Soares, Marco Aurélio; Rosa, Carlos A; Rosa, Luiz H

    2015-11-01

    We surveyed the diversity, distribution and ecology of non-lichenised fungal communities associated with the Antarctic lichens Usnea antarctica and Usnea aurantiaco-atra across Antarctica. The phylogenetic study of the 438 fungi isolates identified 74 taxa from 21 genera of Ascomycota, Basidiomycota and Zygomycota. The most abundant taxa were Pseudogymnoascus sp., Thelebolus sp., Antarctomyces psychrotrophicus and Cryptococcus victoriae, which are considered endemic and/or highly adapted to Antarctica. Thirty-five fungi may represent new and/or endemic species. The fungal communities displayed high diversity, richness and dominance indices; however, the similarity among the communities was variable. After discovering rich and diverse fungal communities composed of symbionts, decomposers, parasites and endemic and cold-adapted cosmopolitan taxa, we introduced the term "lichensphere". We hypothesised that the lichensphere may represent a protected natural microhabitat with favourable conditions able to help non-lichenised fungi and other Antarctic life forms survive and disperse in the extreme environments of Antarctica.

  2. Extremely stable soluble high molecular mass multi-protein complex with DNase activity in human placental tissue.

    Directory of Open Access Journals (Sweden)

    Evgeniya E Burkova

    Full Text Available Human placenta is an organ which protects, feeds, and regulates the grooving of the embryo. Therefore, identification and characterization of placental components including proteins and their multi-protein complexes is an important step to understanding the placenta function. We have obtained and analyzed for the first time an extremely stable multi-protein complex (SPC, ∼ 1000 kDa from the soluble fraction of three human placentas. By gel filtration on Sepharose-4B, the SPC was well separated from other proteins of the placenta extract. Light scattering measurements and gel filtration showed that the SPC is stable in the presence of NaCl, MgCl2, acetonitrile, guanidinium chloride, and Triton in high concentrations, but dissociates efficiently in the presence of 8 M urea, 50 mM EDTA, and 0.5 M NaCl. Such a stable complex is unlikely to be a casual associate of different proteins. According to SDS-PAGE and MALDI mass spectrometry data, this complex contains many major glycosylated proteins with low and moderate molecular masses (MMs 4-14 kDa and several moderately abundant (79.3, 68.5, 52.8, and 27.2 kDa as well as minor proteins with higher MMs. The SPC treatment with dithiothreitol led to a disappearance of some protein bands and revealed proteins with lower MMs. The SPCs from three placentas efficiently hydrolyzed plasmid supercoiled DNA with comparable rates and possess at least two DNA-binding sites with different affinities for a 12-mer oligonucleotide. Progress in study of placental protein complexes can promote understanding of their biological functions.

  3. [Physico-chemical features of dinitrosyl iron complexes with natural thiol-containing ligands underlying biological activities of these complexes].

    Science.gov (United States)

    Vanin, A F; Borodulin, R R; Kubrina, L N; Mikoian, V D; Burbaev, D Sh

    2013-01-01

    Current notions and new experimental data of the authors on physico-chemical features of dinitrosyl iron complexes with natural thiol-containing ligands (glutathione or cysteine), underlying the ability of the complexes to act as NO molecule and nitrosonium ion donors, are considered. This ability determines various biological activities of dinitrosyl iron complexes--inducing long-lasting vasodilation and thereby long-lasting hypotension in human and animals, inhibiting pellet aggregation, increasing red blood cell elasticity, thereby stimulating microcirculation, and reducing necrotic zone in animals with myocardial infarction. Moreover, dinitrosyl iron complexes are capable of accelerating skin wound healing, improving the function of penile cavernous tissue, blocking apoptosis development in cell cultures. When decomposed dinitrosyl iron complexes can exert cytotoxic effect that can be used for curing infectious and carcinogenic pathologies.

  4. Sustaining Economic Exploitation of Complex Ecosystems in Computational Models of Coupled Human-Natural Networks

    OpenAIRE

    Martinez, Neo D.; Tonin, Perrine; Bauer, Barbara; Rael, Rosalyn C.; Singh, Rahul; Yoon, Sangyuk; Yoon, Ilmi; Dunne, Jennifer A.

    2012-01-01

    Understanding ecological complexity has stymied scientists for decades. Recent elucidation of the famously coined "devious strategies for stability in enduring natural systems" has opened up a new field of computational analyses of complex ecological networks where the nonlinear dynamics of many interacting species can be more realistically mod-eled and understood. Here, we describe the first extension of this field to include coupled human-natural systems. This extension elucidates new strat...

  5. A meta-analysis of crop pest and natural enemy response to landscape complexity.

    Science.gov (United States)

    Chaplin-Kramer, Rebecca; O'Rourke, Megan E; Blitzer, Eleanor J; Kremen, Claire

    2011-09-01

    Many studies in recent years have investigated the relationship between landscape complexity and pests, natural enemies and/or pest control. However, no quantitative synthesis of this literature beyond simple vote-count methods yet exists. We conducted a meta-analysis of 46 landscape-level studies, and found that natural enemies have a strong positive response to landscape complexity. Generalist enemies show consistent positive responses to landscape complexity across all scales measured, while specialist enemies respond more strongly to landscape complexity at smaller scales. Generalist enemy response to natural habitat also tends to occur at larger spatial scales than for specialist enemies, suggesting that land management strategies to enhance natural pest control should differ depending on whether the dominant enemies are generalists or specialists. The positive response of natural enemies does not necessarily translate into pest control, since pest abundances show no significant response to landscape complexity. Very few landscape-scale studies have estimated enemy impact on pest populations, however, limiting our understanding of the effects of landscape on pest control. We suggest focusing future research efforts on measuring population dynamics rather than static counts to better characterise the relationship between landscape complexity and pest control services from natural enemies. © 2011 Blackwell Publishing Ltd/CNRS.

  6. Adsorption and desorption of cadmium by synthetic and natural organo-clay complexes

    International Nuclear Information System (INIS)

    Levy, R.; Francis, C.W.; Oak Ridge National Lab., Tenn.

    1976-01-01

    Tracer levels of 109 Cd were used to study the adsorption and desorption of Cd by synthetic and natural organo-clay complexes. Synthetic organo-clay complexes were made by adsorbing humic acid extracted from soil to various forms of 3 ) 2 showed that Cd was adsorbed more tenaciously to the sesquioxides than organo-clay fractions

  7. [Autologous transfusion of UV-irradiated blood in the complex treatment of children with dysplasia of deep veins of the extremities].

    Science.gov (United States)

    Levanovich, V V; Kupatadze, D D; Endzhibadze, Iu G; Nabokov, V V; Mazurova, E V; Ivanov, A P; Chirovich, M

    1991-02-01

    Under examination there were 12 patients aged from 5 till 14 years. An investigation of hemostatic potential of blood in the diseased extremity and peripheral blood was performed. A mosaic character of blood coagulative alterations in this category of patients was detected. Autotransfusion of UV-irradiated blood is a pathogenetically grounded and accessible method of correction of hemocoagulation and may be included in the complex treatment of patients with dysplasia of the profound veins of lower extremities.

  8. Thermodynamics of complex formation of natural iron(III)porphyrins with neutral ligands

    International Nuclear Information System (INIS)

    Lebedeva, Nataliya Sh.; Yakubov, Sergey P.; Vyugin, Anatoly I.; Parfenyuk, Elena V.

    2003-01-01

    Calorimetric titrations in benzene and chloroform at 298.15 K have been performed to give the complexes stability constants and the thermodynamic parameters for the complex formation of nature iron(III)porphyrins with pyridine. Stoichimetry of the complexes formed has been determined. It has been found that the thermodynamic parameters obtained depend on nature of peripheral substituents of the porphyrins. The estimation of the influence of Cl - and Ac - ions on the processes studied has been carried out. Using thermodynamic analysis method, the crystallsolvates of nature iron(III)porphyrins with benzene have been studied. Stoichiometry, thermal and energetic stability of the π-π-complexes formed have been determined. The data obtained have been used to the estimate solvent effect on the thermodynamic parameters of axial coordination of pyridine on the iron(III)porphyrins in benzene

  9. "Bunched Black Swans" in Complex Geosystems: Cross-Disciplinary Approaches to the Additive and Multiplicative Modelling of Correlated Extreme Bursts

    Science.gov (United States)

    Watkins, N. W.; Rypdal, M.; Lovsletten, O.

    2012-12-01

    For all natural hazards, the question of when the next "extreme event" (c.f. Taleb's "black swans") is expected is of obvious importance. In the environmental sciences users often frame such questions in terms of average "return periods", e.g. "is an X meter rise in the Thames water level a 1-in-Y year event ?". Frequently, however, we also care about the emergence of correlation, and whether the probability of several big events occurring in close succession is truly independent, i.e. are the black swans "bunched". A "big event", or a "burst", defined by its integrated signal above a threshold, might be a single, very large, event, or, instead, could in fact be a correlated series of "smaller" (i.e. less wildly fluctuating) events. Several available stochastic approaches provide quantitative information about such bursts, including Extreme Value Theory (EVT); the theory of records; level sets; sojourn times; and models of space-time "avalanches" of activity in non-equilibrium systems. Some focus more on the probability of single large events. Others are more concerned with extended dwell times above a given spatiotemporal threshold: However, the state of the art is not yet fully integrated, and the above-mentioned approaches differ in fundamental aspects. EVT is perhaps the best known in the geosciences. It is concerned with the distribution obeyed by the extremes of datasets, e.g. the 100 values obtained by considering the largest daily temperature recorded in each of the years of a century. However, the pioneering work from the 1920s on which EVT originally built was based on independent identically distributed samples, and took no account of memory and correlation that characterise many natural hazard time series. Ignoring this would fundamentally limit our ability to forecast; so much subsequent activity has been devoted to extending EVT to encompass dependence. A second group of approaches, by contrast, has notions of time and thus possible non

  10. Extreme pollution of soils by emissions of the copper-nickel industrial complex in the Kola Peninsula

    Science.gov (United States)

    Kashulina, G. M.

    2017-07-01

    The distribution of the total Ni, Cu, Co, Cd, Pb, and Zn contents was studied in the soil profiles of six catenas in the zone subjected to emissions of the copper-nickel industrial complex, which is the largest source of SO2 and heavy metals in northern Europe. The results show that, at present, the concentrations of Ni and Cu in the upper organic soil horizons in the impact zone reach extreme levels of 9000 and 6000 mg/kg, respectively. Under conditions of the long-term intense multi-element industrial emissions, the modern levels of the accumulation of polluting substances in soils greatly depend on the indirect factors, such as the degree of the technogenic degradation of soils with the loss of a significant part of soil organic matter, the reaching of threshold saturation of the topsoil with polluting metals, and competitive relationships between chemical elements. The state of the ecosystems in the impact zone varied greatly and did not always agree with the contents of the main metals-pollutants in the soils. The moisture conditions determined by the landscape position affected significantly the resistance of the ecosystems to emissions.

  11. Excitation energy transfer in natural photosynthetic complexes and chlorophyll trefoils: hole-burning and single complex/trefoil spectroscopic studies

    Energy Technology Data Exchange (ETDEWEB)

    Ryszard Jankowiak, Kansas State University, Department of Chemistry, CBC Bldg., Manhattan KS, 66505; Phone: (785) 532-6785

    2012-09-12

    In this project we studied both natural photosynthetic antenna complexes and various artificial systems (e.g. chlorophyll (Chl) trefoils) using high resolution hole-burning (HB) spectroscopy and excitonic calculations. Results obtained provided more insight into the electronic (excitonic) structure, inhomogeneity, electron-phonon coupling strength, vibrational frequencies, and excitation energy (or electron) transfer (EET) processes in several antennas and reaction centers. For example, our recent work provided important constraints and parameters for more advanced excitonic calculations of CP43, CP47, and PSII core complexes. Improved theoretical description of HB spectra for various model systems offers new insight into the excitonic structure and composition of low-energy absorption traps in very several antenna protein complexes and reaction centers. We anticipate that better understanding of HB spectra obtained for various photosynthetic complexes and their simultaneous fits with other optical spectra (i.e. absorption, emission, and circular dichroism spectra) provides more insight into the underlying electronic structures of these important biological systems. Our recent progress provides a necessary framework for probing the electronic structure of these systems via Hole Burning Spectroscopy. For example, we have shown that the theoretical description of non-resonant holes is more restrictive (in terms of possible site energies) than those of absorption and emission spectra. We have demonstrated that simultaneous description of linear optical spectra along with HB spectra provides more realistic site energies. We have also developed new algorithms to describe both nonresonant and resonant hole-burn spectra using more advanced Redfield theory. Simultaneous description of various optical spectra for complex biological system, e.g. artificial antenna systems, FMO protein complexes, water soluble protein complexes, and various mutants of reaction centers

  12. NMR detected metabolites in complex natural fluids. Quinic acid in apple juice

    Directory of Open Access Journals (Sweden)

    Ailiesei Gabriela Liliana

    2015-12-01

    Full Text Available Different types of 1D and 2D NMR experiments were used to completely characterize quinic acid and demonstrate its presence in complex mixtures. The identification of quinic acid in apple juice was done without any separation step. The NMR experiments presented in this study can be used to analyze other metabolites in different complex natural fluids, of vegetal or biological origin.

  13. Review of complex networks application in hydroclimatic extremes with an implementation to characterize spatio-temporal drought propagation in continental USA

    Science.gov (United States)

    Konapala, Goutam; Mishra, Ashok

    2017-12-01

    The quantification of spatio-temporal hydroclimatic extreme events is a key variable in water resources planning, disaster mitigation, and preparing climate resilient society. However, quantification of these extreme events has always been a great challenge, which is further compounded by climate variability and change. Recently complex network theory was applied in earth science community to investigate spatial connections among hydrologic fluxes (e.g., rainfall and streamflow) in water cycle. However, there are limited applications of complex network theory for investigating hydroclimatic extreme events. This article attempts to provide an overview of complex networks and extreme events, event synchronization method, construction of networks, their statistical significance and the associated network evaluation metrics. For illustration purpose, we apply the complex network approach to study the spatio-temporal evolution of droughts in Continental USA (CONUS). A different drought threshold leads to a new drought event as well as different socio-economic implications. Therefore, it would be interesting to explore the role of thresholds on spatio-temporal evolution of drought through network analysis. In this study, long term (1900-2016) Palmer drought severity index (PDSI) was selected for spatio-temporal drought analysis using three network-based metrics (i.e., strength, direction and distance). The results indicate that the drought events propagate differently at different thresholds associated with initiation of drought events. The direction metrics indicated that onset of mild drought events usually propagate in a more spatially clustered and uniform approach compared to onsets of moderate droughts. The distance metric shows that the drought events propagate for longer distance in western part compared to eastern part of CONUS. We believe that the network-aided metrics utilized in this study can be an important tool in advancing our knowledge on drought

  14. On dependence of stability of lanthanide(3) complexes with coloured ligands on the element nature

    International Nuclear Information System (INIS)

    Poluehktov, N.S.; Meshkova, S.B.; Rusakova, N.V.

    1984-01-01

    The change in the colour intensity of Ln(3) complexes with coloured ligands (methyl thymol blue, glycine cresol red, stilbazo, glycine thymol blue, methyl ortanyl S, ortanyl B, phthalexone S, semiphthalexone S, cresolphtalexone, sulfarsazen) in the natural series of lanthanoids is considered. A correlation equation is suggested that permits to describe the relative colour intensity (quenching molar coefficients, stability constants) of complexes in the series of lanthanide(3) ions versus the number of f-electrons, spin and orbital quantum numbers of the ground states. Using the ratio obtained it is possible to calculate the values of appropriate functions of complexes of elements for which such data are not available

  15. Dependence of stability of lanthanide(3) complexes with coloured ligands on the element nature

    Energy Technology Data Exchange (ETDEWEB)

    Poluehktov, N S; Meshkova, S B; Rusakova, N V [AN Ukrainskoj SSR, Odessa. Fiziko-Khimicheskij Inst.

    1984-07-01

    The change in the colour intensity of Ln(3) complexes with coloured ligands (methyl thymol blue, glycine cresol red, stilbazo, glycine thymol blue, methyl ortanyl S, ortanyl B, phthalexone S, semiphthalexone S, cresolphtalexone, sulfarsazen) in the natural series of lanthanoids is considered. A correlation equation is suggested that permits to describe the relative colour intensity (quenching molar coefficients, stability constants) of complexes in the series of lanthanide(3) ions versus the number of f-electrons, spin and orbital quantum numbers of the ground states. Using the ratio obtained it is possible to calculate the values of appropriate functions of complexes of elements for which such data are not available.

  16. Dinamics of radiating conditions in the natural complexes of a near zone of the Chernobyl NPP

    International Nuclear Information System (INIS)

    Bondar', Yu.I.; Kalinichenko, S.A.; Marchenko, Yu.D.

    2010-01-01

    The analysis of radiating conditions in exclusion zone of Chernobyl NPP is resulted. Annual and seasonal fluctuations of capacity of a dose, and also change of parameters of vertical migration Cs 137, Sr 90, Am 241 in a vertical profile of soils of various territorially-natural complexes are considered. (authors)

  17. Structuring nature´s and science´s complexity

    OpenAIRE

    Leiber, Theodor

    2007-01-01

    Structuring nature´s and science´s complexity : system laws and explanations. - In: Dynamisches Denken und Handeln : Philosophie und Wissenschaft in einer komplexen Welt ; Festschrift für Klaus Mainzer zum 60. Geburtstag / Theodor Leiber (Hg.). - Stuttgart : Hirzel, 2007. - S. 193-212

  18. Neutral Theory: From Complex Population History to Natural Selection and Sociocultural Phenomena in Human Populations.

    Science.gov (United States)

    Austerlitz, Frédéric; Heyer, Evelyne

    2018-06-01

    Here, we present a synthetic view on how Kimura's Neutral theory has helped us gaining insight on the different evolutionary forces that shape human evolution. We put this perspective in the frame of recent emerging challenges: the use of whole genome data for reconstructing population histories, natural selection on complex polygenic traits, and integrating cultural processes in human evolution.

  19. Strain-dependent susceptibility for hypertension in mice resides in the natural killer gene complex

    NARCIS (Netherlands)

    Taherzadeh, Zhila; VanBavel, Ed; de Vos, Judith; Matlung, Hanke L.; van Montfrans, Gert; Brewster, Lizzy M.; Seghers, Leonard; Quax, Paul H. A.; Bakker, Erik N. T. P.

    2010-01-01

    Taherzadeh Z, VanBavel E, de Vos J, Matlung HL, van Montfrans G, Brewster LM, Seghers L, Quax PH, Bakker EN. Strain-dependent susceptibility for hypertension in mice resides in the natural killer gene complex. Am J Physiol Heart Circ Physiol 298: H1273-H1282, 2010. First published February 12, 2010;

  20. Study of vitamin A derivative complexation in natural and modified cyclodextrins

    International Nuclear Information System (INIS)

    Weisse, Sandrine

    1999-01-01

    This research thesis reports a test of solubilisation and stabilisation of retinol, a highly hydrophobic and unsteady molecule, by natural or modified cyclodextrins. The author first recalls retinol physical-chemical characteristics, and then evokes the different techniques (other than cyclodextrins) used to modify these characteristics. Then, the author addresses the complexes of inclusion of retinol in cyclodextrins, and the associated characterization techniques [fr

  1. Updated procedure for the safety evaluation of natural flavor complexes used as ingredients in food

    NARCIS (Netherlands)

    Cohen, Samuel M.; Eisenbrand, Gerhard; Fukushima, Shoji; Gooderham, Nigel J.; Guengerich, F.P.; Hecht, Stephen S.; Rietjens, Ivonne M.C.M.; Davidsen, Jeanne M.; Harman, Christie L.; Taylor, Sean V.

    2018-01-01

    An effective and thorough approach for the safety evaluation of natural flavor complexes (NFCs) was published in 2005 by the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA). An updated procedure is provided here, which maintains the essential concepts of the use of the

  2. Utilization of manual therapy to the lumbar spine in conjunction with traditional conservative care for individuals with bilateral lower extremity complex regional pain syndrome: A case series.

    Science.gov (United States)

    Walston, Zachary; Hernandez, Luis; Yake, Dale

    2018-06-06

    Conservative therapies for complex regional pain syndrome (CRPS) have traditionally focused on exercise and desensitization techniques targeted at the involved extremity. The primary purpose of this case series is to report on the potential benefit of utilizing manual therapy to the lumbar spine in conjunction with traditional conservative care when treating patients with lower extremity CRPS. Two patients with the diagnosis of lower extremity CRPS were treated with manual therapy to the lumbar spine in conjunction with education, exercise, desensitization, and soft tissue techniques for the extremity. Patient 1 received 13 sessions over 6 weeks resulting in a 34-point improvement in oswestry disability index (ODI) and 35-point improvement in lower extremity functional scale (LEFS). Patient 2 received 21 sessions over 12 weeks resulting in a 28-point improvement in ODI and a 41-point improvement in LEFS. Both patients exhibited reductions in pain and clinically meaningful improvements in function. Manual therapies when applied to the lumbar spine in these patients as part of a comprehensive treatment plan resulted in improved spinal mobility, decreased pain, and reduction is distal referred symptoms. Although one cannot infer a cause and effect relationship from a case series, this report identifies meaningful clinical outcomes potentially associated with manual physical therapy to the lumbar spine for two patients with complex regional pain syndrome type 1.

  3. Adapting to extreme events related to natural variability and climate change: the imperative of coupling technology with strong regulation and governance.

    Science.gov (United States)

    Kythreotis, A P; Mercer, T G; Frostick, L E

    2013-09-03

    In recent years there has been an increase in extreme events related to natural variability (such as earthquakes, tsunamis and hurricanes) and climate change (such as flooding and more extreme weather). Developing innovative technologies is crucial in making society more resilient to such events. However, little emphasis has been placed on the role of human decision-making in maximizing the positive impacts of technological developments. This is exacerbated by the lack of appropriate adaptation options and the privatization of existing infrastructure, which can leave people exposed to increasing risk. This work examines the need for more robust government regulation and legislation to complement developments and innovations in technology in order to protect communities against such extreme events.

  4. Atomic switch networks-nanoarchitectonic design of a complex system for natural computing.

    Science.gov (United States)

    Demis, E C; Aguilera, R; Sillin, H O; Scharnhorst, K; Sandouk, E J; Aono, M; Stieg, A Z; Gimzewski, J K

    2015-05-22

    Self-organized complex systems are ubiquitous in nature, and the structural complexity of these natural systems can be used as a model to design new classes of functional nanotechnology based on highly interconnected networks of interacting units. Conventional fabrication methods for electronic computing devices are subject to known scaling limits, confining the diversity of possible architectures. This work explores methods of fabricating a self-organized complex device known as an atomic switch network and discusses its potential utility in computing. Through a merger of top-down and bottom-up techniques guided by mathematical and nanoarchitectonic design principles, we have produced functional devices comprising nanoscale elements whose intrinsic nonlinear dynamics and memorization capabilities produce robust patterns of distributed activity and a capacity for nonlinear transformation of input signals when configured in the appropriate network architecture. Their operational characteristics represent a unique potential for hardware implementation of natural computation, specifically in the area of reservoir computing-a burgeoning field that investigates the computational aptitude of complex biologically inspired systems.

  5. Atomic switch networks—nanoarchitectonic design of a complex system for natural computing

    International Nuclear Information System (INIS)

    Demis, E C; Aguilera, R; Sillin, H O; Scharnhorst, K; Sandouk, E J; Gimzewski, J K; Aono, M; Stieg, A Z

    2015-01-01

    Self-organized complex systems are ubiquitous in nature, and the structural complexity of these natural systems can be used as a model to design new classes of functional nanotechnology based on highly interconnected networks of interacting units. Conventional fabrication methods for electronic computing devices are subject to known scaling limits, confining the diversity of possible architectures. This work explores methods of fabricating a self-organized complex device known as an atomic switch network and discusses its potential utility in computing. Through a merger of top-down and bottom-up techniques guided by mathematical and nanoarchitectonic design principles, we have produced functional devices comprising nanoscale elements whose intrinsic nonlinear dynamics and memorization capabilities produce robust patterns of distributed activity and a capacity for nonlinear transformation of input signals when configured in the appropriate network architecture. Their operational characteristics represent a unique potential for hardware implementation of natural computation, specifically in the area of reservoir computing—a burgeoning field that investigates the computational aptitude of complex biologically inspired systems. (paper)

  6. Natural antimicrobial peptide complexes in the fighting of antibiotic resistant biofilms: Calliphora vicina medicinal maggots.

    Directory of Open Access Journals (Sweden)

    Natalia Gordya

    Full Text Available Biofilms, sedimented microbial communities embedded in a biopolymer matrix cause vast majority of human bacterial infections and many severe complications such as chronic inflammatory diseases and cancer. Biofilms' resistance to the host immunity and antibiotics makes this kind of infection particularly intractable. Antimicrobial peptides (AMPs are a ubiquitous facet of innate immunity in animals. However, AMPs activity was studied mainly on planktonic bacteria and little is known about their effects on biofilms. We studied structure and anti-biofilm activity of AMP complex produced by the maggots of blowfly Calliphora vicina living in environments extremely contaminated by biofilm-forming germs. The complex exhibits strong cell killing and matrix destroying activity against human pathogenic antibiotic resistant Escherichia coli, Staphylococcus aureus and Acinetobacter baumannii biofilms as well as non-toxicity to human immune cells. The complex was found to contain AMPs from defensin, cecropin, diptericin and proline-rich peptide families simultaneously expressed in response to bacterial infection and encoded by hundreds mRNA isoforms. All the families combine cell killing and matrix destruction mechanisms, but the ratio of these effects and antibacterial activity spectrum are specific to each family. These molecules dramatically extend the list of known anti-biofilm AMPs. However, pharmacological development of the complex as a whole can provide significant advantages compared with a conventional one-component approach. In particular, a similar level of activity against biofilm and planktonic bacteria (MBEC/MIC ratio provides the complex advantage over conventional antibiotics. Available methods of the complex in situ and in vitro biosynthesis make this idea practicable.

  7. Natural antimicrobial peptide complexes in the fighting of antibiotic resistant biofilms: Calliphora vicina medicinal maggots.

    Science.gov (United States)

    Gordya, Natalia; Yakovlev, Andrey; Kruglikova, Anastasia; Tulin, Dmitry; Potolitsina, Evdokia; Suborova, Tatyana; Bordo, Domenico; Rosano, Camillo; Chernysh, Sergey

    2017-01-01

    Biofilms, sedimented microbial communities embedded in a biopolymer matrix cause vast majority of human bacterial infections and many severe complications such as chronic inflammatory diseases and cancer. Biofilms' resistance to the host immunity and antibiotics makes this kind of infection particularly intractable. Antimicrobial peptides (AMPs) are a ubiquitous facet of innate immunity in animals. However, AMPs activity was studied mainly on planktonic bacteria and little is known about their effects on biofilms. We studied structure and anti-biofilm activity of AMP complex produced by the maggots of blowfly Calliphora vicina living in environments extremely contaminated by biofilm-forming germs. The complex exhibits strong cell killing and matrix destroying activity against human pathogenic antibiotic resistant Escherichia coli, Staphylococcus aureus and Acinetobacter baumannii biofilms as well as non-toxicity to human immune cells. The complex was found to contain AMPs from defensin, cecropin, diptericin and proline-rich peptide families simultaneously expressed in response to bacterial infection and encoded by hundreds mRNA isoforms. All the families combine cell killing and matrix destruction mechanisms, but the ratio of these effects and antibacterial activity spectrum are specific to each family. These molecules dramatically extend the list of known anti-biofilm AMPs. However, pharmacological development of the complex as a whole can provide significant advantages compared with a conventional one-component approach. In particular, a similar level of activity against biofilm and planktonic bacteria (MBEC/MIC ratio) provides the complex advantage over conventional antibiotics. Available methods of the complex in situ and in vitro biosynthesis make this idea practicable.

  8. Poly-functional description of metal complexation by natural organic matter: theory and practice

    International Nuclear Information System (INIS)

    Buffle, J.; Filella, M.; Altmann, R.S.

    1995-01-01

    The Differential Equilibrium Function (DEF) approach to metal complexation interpretation and prediction is compared to other models or approaches. The basic features of DEF are summarized, both from the experimental and theoretical points of view. The relation of DEF with key environmental concepts or parameters, in particular minor vs major complexing sites, the buffering intensity of natural organic matter (NOM), and their poly functional vs polyelectrolyte properties, is discussed. The relation between DEF and Freundlich isotherm is described quantitatively. The practical applications of DEF are discussed for (i) interpretation of metal complexation by NOM, and (ii) prediction of metal complexation by NOM. It is shown that DEF (i.e. sound extrapolation is possible with care). DEF cans be readily incorporated in metal species distribution codes (e.g. MINEQL). DEF is not equivalent to a molecular complexation model which describes complexation at each individual site; DEF gives a rigorous representation of complexation by NOM as a whole chemical system. (authors). 23 refs., 6 figs

  9. A hydro-meteorological model chain to assess the influence of natural variability and impacts of climate change on extreme events and propose optimal water management

    Science.gov (United States)

    von Trentini, F.; Willkofer, F.; Wood, R. R.; Schmid, F. J.; Ludwig, R.

    2017-12-01

    The ClimEx project (Climate change and hydrological extreme events - risks and perspectives for water management in Bavaria and Québec) focuses on the effects of climate change on hydro-meteorological extreme events and their implications for water management in Bavaria and Québec. Therefore, a hydro-meteorological model chain is applied. It employs high performance computing capacity of the Leibniz Supercomputing Centre facility SuperMUC to dynamically downscale 50 members of the Global Circulation Model CanESM2 over European and Eastern North American domains using the Canadian Regional Climate Model (RCM) CRCM5. Over Europe, the unique single model ensemble is conjointly analyzed with the latest information provided through the CORDEX-initiative, to better assess the influence of natural climate variability and climatic change in the dynamics of extreme events. Furthermore, these 50 members of a single RCM will enhance extreme value statistics (extreme return periods) by exploiting the available 1500 model years for the reference period from 1981 to 2010. Hence, the RCM output is applied to drive the process based, fully distributed, and deterministic hydrological model WaSiM in high temporal (3h) and spatial (500m) resolution. WaSiM and the large ensemble are further used to derive a variety of hydro-meteorological patterns leading to severe flood events. A tool for virtual perfect prediction shall provide a combination of optimal lead time and management strategy to mitigate certain flood events following these patterns.

  10. Sorption and leaching properties of the composites and humic complexes of natural microporous materials

    International Nuclear Information System (INIS)

    Masasek, F.

    1998-01-01

    This contribution deals with scientific basis and engineering practices of natural microporous materials (NMM) which are projected for a millennia horizon of the environmental protection. Microcrystalline structure of inorganic microporous sorbents is discussed. Artificial formation composites and both inorganic and organic complexes of NMM is applied for> (1) field barriers, fills or supporting structures, (2) reagents and organic coating supports, (3) granules, pellets and column packings, (4) additives to cementitious fixation matrices, and (4) glass formulations

  11. A pragmatic approach to including complex natural modes of vibration in aeroelastic analysis

    CSIR Research Space (South Africa)

    Van Zyl, Lourens H

    2015-09-01

    Full Text Available complex natural modes of vibration in aeroelastic analysis Louw van Zyl International Aerospace Symposium of South Africa 14 to 16 September, 2015 Stellenbosch, South Africa Slide 2 © CSIR 2006 www.csir.co.za Problem statement..., the square of the angular frequencies in radians per second) [ ]{ } [ ]{ } [ ]{ } { }fxKxCxM =++ &&& [ ]{ } [ ]{ } 0=+ xKxMs2 Slide 4 © CSIR 2006 www.csir.co.za Structural Dynamics (continued) • The corresponding eigenvectors are real...

  12. Floristic quality assessment of one natural and three restored wetland complexes in North Dakota, USA

    Science.gov (United States)

    Mushet, David M.; Euliss, Ned H.; Shaffer, Terry L.

    2002-01-01

    Floristic quality assessment is potentially an important tool for conservation efforts in the northern Great Plains of North America, but it has received little rigorous evaluation. Floristic quality assessments rely on coefficients assigned to each plant species of a region’s flora based on the conservatism of each species relative to others in the region. These “coefficients of conservatism” (C values) are assigned by a panel of experts familiar with a region’s flora. The floristic quality assessment method has faced some criticism due to the subjective nature of these assignments. To evaluate the effect of this subjectivity on floristic quality assessments, we performed separate evaluations of the native plant communities in a natural wetland complex and three restored wetland complexes. In our first assessment, we used C values assigned “subjectively” by the Northern Great Plains Floristic Quality Assessment Panel. We then performed an independent assessment using the observed distributions of species among a group of wetlands that ranged from highly disturbed to largely undisturbed (data-generated C values). Using the panel-assigned C values, mean C values (C¯">C¯C¯) of the restored wetlands rarely exceeded 3.4 and never exceeded 3.9, with the highest values occurring in the oldest restored complex; all but two wetlands in the natural wetland complex had a C¯">C¯C¯ greater than 3.9. Floristic quality indices (FQI) for the restored wetlands rarely exceeded 22 and usually reached maximums closer to 19, with higher values occurring again in the oldest restored complex; only two wetlands in the natural complex had an FQI less than 22. We observed that 95% confidence limits for species richness and percent natives overlapped greatly among wetland complexes, whereas confidence limits for both C¯">C¯C¯ and FQI overlapped little. C¯">C¯C¯ and FQI values were consistently greater when we used the datagenerated C values than when we used the

  13. Investigations on complexing cation exchangers and their use for trace analysis in natural waters

    International Nuclear Information System (INIS)

    Lang, H.

    1991-12-01

    The practicability of cation preconcentrations from natural waters by use of EDTrA- and 5-s-oxine- celluloses has been studied. For that purpose the protonation constants as well as the complexation capacities were determined by use of acid/base titrations. In additional titration experiments the complex stability constants for Cu 2+ , Mn 2+ , Co 2+ , Ni 2+ and Ca 2+ were determined examplarely. The interpretation of the experiments was performed using an optimised fit between calculated and experimentally determined pH-titration curves. Calculations have been done by the computer code 'MINEQL'. The determined stability constants are in the same order of magnitude as those given in literature for the water soluble complexes of EDTA, NTA or 5-s-oxine. The preconcentration of cations from natural water samples occurs in accordance with the theoretical predictions. Not ignorable disturbances appear for cations forming hydroxides or oxides in neutral or weakly acidic solutions. By use of radioactive isotopes for Sn 2+ , Zn 4+ and Nb 5+ it can be shown that those ions may form particles or colloids in natural waters. These particles will be filtered in the columns packed with the celluloses and can hardly be removed from there. (author)

  14. [Intermittent pneumatic compression of the lower extremity muscles in complex prophylactics of postoperative venous thromboses in elderly and senile patients].

    Science.gov (United States)

    Glushkov, N I; Openchenko, S V

    2009-01-01

    An analysis of frequency of venous thrombitic complications after different operations on 69 patients aged from 69 through 87 was made. The greatest number of venous thromboses was noted after amputations of the femur. Intermittent pneumatic compression of the lower extremities in addition to standard methods of prophylactics reduced the number of postoperative thromboses from 12.8% to 3.3%.

  15. Long-Term Memory: A Natural Mechanism for the Clustering of Extreme Events and Anomalous Residual Times in Climate Records

    Science.gov (United States)

    Bunde, Armin; Eichner, Jan F.; Kantelhardt, Jan W.; Havlin, Shlomo

    2005-01-01

    We study the statistics of the return intervals between extreme events above a certain threshold in long-term persistent records. We find that the long-term memory leads (i)to a stretched exponential distribution of the return intervals, (ii)to a pronounced clustering of extreme events, and (iii)to an anomalous behavior of the mean residual time to the next event that depends on the history and increases with the elapsed time in a counterintuitive way. We present an analytical scaling approach and demonstrate that all these features can be seen in long climate records. The phenomena should also occur in heartbeat records, Internet traffic, and stock market volatility and have to be taken into account for an efficient risk evaluation.

  16. Exploring the Interaction Natures in Plutonyl (VI Complexes with Topological Analyses of Electron Density

    Directory of Open Access Journals (Sweden)

    Jiguang Du

    2016-04-01

    Full Text Available The interaction natures between Pu and different ligands in several plutonyl (VI complexes are investigated by performing topological analyses of electron density. The geometrical structures in both gaseous and aqueous phases are obtained with B3LYP functional, and are generally in agreement with available theoretical and experimental results when combined with all-electron segmented all-electron relativistic contracted (SARC basis set. The Pu– O y l bond orders show significant linear dependence on bond length and the charge of oxygen atoms in plutonyl moiety. The closed-shell interactions were identified for Pu-Ligand bonds in most complexes with quantum theory of atoms in molecules (QTAIM analyses. Meanwhile, we found that some Pu–Ligand bonds, like Pu–OH−, show weak covalent. The interactive nature of Pu–ligand bonds were revealed based on the interaction quantum atom (IQA energy decomposition approach, and our results indicate that all Pu–Ligand interactions is dominated by the electrostatic attraction interaction as expected. Meanwhile it is also important to note that the quantum mechanical exchange-correlation contributions can not be ignored. By means of the non-covalent interaction (NCI approach it has been found that some weak and repulsion interactions existed in plutonyl(VI complexes, which can not be distinguished by QTAIM, can be successfully identified.

  17. Mitigating Local Natural Disaster through Social Aware Preparedness Using Complexity Approach

    Science.gov (United States)

    Supadli, Irwan; Saputri, Andini; Mawengkang, Herman

    2018-01-01

    During and after natural disaster, such as, eruption of vulcano, many people have to abandon their living place to a temporary shelter. Usually, there could be several time for the occurrence of the eruption. This situation, for example, happened at Sinabung vulcano, located in Karo district of North Sumatera Province, Indonesia. The people in the disaster area have become indifferent. In terms of the society, the local natural disaster problem belong to a complex societal problem. This research is to find a way what should be done to these society to raise their social awareness that they had experienced serious natural disaster and they will be able to live normally and sustainable as before. Societal complexity approach is used to solve the problems. Social studies referred to in this activity are to analyze the social impacts arising from the implementation of the relocation itself. Scope of social impact assessments include are The social impact of the development program of relocation, including the impact of construction activities and long-term impact of construction activity, particularly related to the source and use of clean water, sewerage system, drainage and waste management (solid waste), Social impacts arising associated with occupant relocation sites and the availability of infrastructure (public facilities, include: worship facilities, health and education) in the local environment (pre-existing). Social analysis carried out on the findings of the field, the study related documents and observations of the condition of the existing social environment Siosar settlements.

  18. Using an Insect Mushroom Body Circuit to Encode Route Memory in Complex Natural Environments.

    Directory of Open Access Journals (Sweden)

    Paul Ardin

    2016-02-01

    Full Text Available Ants, like many other animals, use visual memory to follow extended routes through complex environments, but it is unknown how their small brains implement this capability. The mushroom body neuropils have been identified as a crucial memory circuit in the insect brain, but their function has mostly been explored for simple olfactory association tasks. We show that a spiking neural model of this circuit originally developed to describe fruitfly (Drosophila melanogaster olfactory association, can also account for the ability of desert ants (Cataglyphis velox to rapidly learn visual routes through complex natural environments. We further demonstrate that abstracting the key computational principles of this circuit, which include one-shot learning of sparse codes, enables the theoretical storage capacity of the ant mushroom body to be estimated at hundreds of independent images.

  19. Assessing the natural and anthropogenic charges of radioactivity in complex ecosystems

    International Nuclear Information System (INIS)

    El-Daoushy, F.

    2010-01-01

    Large-scale and long-term assessment of nuclear disasters depends on transport and chemistry processes. Chernobyl dominated by tropospheric and local surface water processes. Assessment strategies for the Nile Basin , and other African rivers, would be different. European surface water are primarily forced by atmospheric and local catchment interactions. Surface water are multi-scale systems with local, regional & global interactions. Natural and artificial radioactivity were assessed in European inland waters. Scales and interactions were detailed using Lake-catchment systems. Surface water interactions in the Nile Basin has much more large scale dynamics as compared by the European ones. The spatio-temporal scales of this complex river system are much more comprehensive due to its complex boundaries and intensive coupling with climate and environment. Lakes and rivers are space-time indicators of atmospheric and land-based human activities

  20. Interaction of natural complexing agents with soil bound heavy metals -geochemical and environmental technical aspects

    International Nuclear Information System (INIS)

    Fischer, K.

    1994-01-01

    The sanitation of heavy metal polluted soils requires the application of an adequate technology, which should be consistent in its ecological aims and methodology. Therefore a research programme has been developed at the 'Institute of Ecological Chemistry' of the 'GSF-Research Center', Neuherberg, which has its starting point in the study of influences of natural organic complexing agents on the chemical activity and dynamic of heavy metals in soils. The groundlaying idea is to elevate the concentration of complexing agents in the soil solution by additional application and possible stimulation of their microbial production to such an extent, that heavy metals will be enhanced solubilized, mobilized and removed together with the seepage water. Batch experiments in order to extract heavy metals from typical soil components (bentonite, peat) by amino acids demonstrate, that removal rates up to 95% can be obtained. (orig.) [de

  1. The Lutzomyia longipalpis complex: a brief natural history of aggregation-sex pheromone communication.

    Science.gov (United States)

    Spiegel, Carolina N; Dias, Denise B Dos Santos; Araki, Alejandra S; Hamilton, James G C; Brazil, Reginaldo P; Jones, Théresa M

    2016-11-14

    In this paper we review the natural history of pheromone communication and the current diversity of aggregation-sex pheromones in the sand fly Lutzomyia longipalpis. This species complex is the main vector of Leishmania infantum, the agent of visceral leishmaniasis in the Americas. The identification of variation in pheromone chemotypes combined with molecular and sound analyses have all contributed to our understanding of the extent of divergence among cryptic members of this complex. The importance of chemical signals as pre-mating barriers and drivers of speciation is discussed. Moreover, the importance of aggregation-sex pheromones as sexually selected signals is highlighted with evidence from the literature suggesting their potential role in species and mate recognition as well as mate assessment. The distinct evolutionary forces possibly involved are briefly reviewed and discussed in the context of this intriguing insect.

  2. Structural analysis and binding domain of albumin complexes with natural dietary supplement humic acid

    International Nuclear Information System (INIS)

    Ding Fei; Diao Jianxiong; Yang Xinling; Sun Ying

    2011-01-01

    Humic acid, a natural ionic molecule, is rapidly being recognized as one of the crucial elements in our modern diets of the new century. A biophysical protocol utilizing circular dichroism (CD), steady state and time-resolved fluorescence for the investigation of the complexation of the humic acid to the staple in vivo transporter, human serum albumin (HSA), as a model for protein-humic substances, is proclaimed. The alterations of CD and three-dimensional fluorescence suggest that the polypeptide chain of HSA partially folded after complexation with humic acid. The data of fluorescence emission displayed that the binding of humic acid to HSA is the formation of HSA-humic acid complex with an association constant of 10 4 M -1 ; this corroborates the fluorescence lifetime measurements that the static mechanism was operated. The precise binding domain of humic acid in HSA has been verified from the denaturation of albumin, hydrophobic ANS displacement, and site-specific ligands; subdomain IIA (Sudlow's site I) was earmarked to possess high-affinity for humic acid. The observations are relevant for other albumin-humic substance systems when the ligands have analogous configuration with humic acid. - Highlights: → Albumin structure partially folds upon humic acid complexation. → Static type is dominance for the diminution in the Trp-214 fluorescence.→ Subdomain IIA is designate to possess high-affinity site for humic acid.

  3. Ant Queen Egg-Marking Signals: Matching Deceptive Laboratory Simplicity with Natural Complexity

    DEFF Research Database (Denmark)

    van Zweden, Jelle Stijn; Heinze, Jürgen; Boomsma, Jacobus Jan

    2009-01-01

    Background Experiments under controlled laboratory conditions can produce decisive evidence for testing biological hypotheses, provided they are representative of the more complex natural conditions. However, whether this requirement is fulfilled is seldom tested explicitly. Here we provide a lab....../field comparison to investigate the identity of an egg-marking signal of ant queens. Our study was based on ant workers resolving conflict over male production by destroying each other's eggs, but leaving queen eggs unharmed. For this, the workers need a proximate cue to discriminate between the two egg types...... that this compound by itself is not the natural queen egg-marking pheromone. We subsequently investigated the overall differences of entire chemical profiles of eggs, and found that queen-laid eggs in field colonies are more distinct from worker-laid eggs than in lab colonies, have more variation in profiles...

  4. Associations of Volatile Compounds with Sensory Aroma and Flavor: The Complex Nature of Flavor

    Directory of Open Access Journals (Sweden)

    Edgar Chambers IV

    2013-04-01

    Full Text Available Attempts to relate sensory analysis data to specific chemicals such as volatile compounds have been frequent. Often these associations are difficult to interpret or are weak in nature. Although some difficulties may relate to the methods used, the difficulties also result from the complex nature of flavor. For example, there are multiple volatiles responsible for a flavor sensation, combinations of volatiles yield different flavors than those expected from individual compounds, and the differences in perception of volatiles in different matrices. This review identifies some of the reasons sensory analysis and instrumental measurements result in poor associations and suggests issues that need to be addressed in future research for better understanding of the relationships of flavor/aroma phenomena and chemical composition.

  5. [Case of anti VGKC-complex antibody associated disorder presenting with severe pain and fasciculations predominant in unilateral upper extremity].

    Science.gov (United States)

    Hara, Kenju; Watanabe, Osamu; Shibano, Ken; Ishiguro, Hideaki

    2012-01-01

    A 21-year-old man complained of severe pain and muscle twitching localized in his right arm. Neurological examination showed muscle fasciculations in his right forearm but no myokymia or myotonia. Needle electromyography revealed fibrillation potentials in his biceps brachii muscle and extensor carpi radialis muscle at rest but no myokymic discharges. His serum anti-voltage-gated potassium channel (VGKC)-complex antibody level was significantly high (194.2pM; controls VGKC-complex antibody associated disorder.

  6. Observed changes of temperature extremes during 1960-2005 in China: natural or human-induced variations?

    Science.gov (United States)

    Zhang, Qiang; Li, Jianfeng; David Chen, Yongqin; Chen, Xiaohong

    2011-12-01

    The purpose of this study was to statistically examine changes of surface air temperature in time and space and to analyze two factors potentially influencing air temperature changes in China, i.e., urbanization and net solar radiation. Trends within the temperature series were detected by using Mann-Kendall trend test technique. The scientific problem this study expected to address was that what could be the role of human activities in the changes of temperature extremes. Other influencing factors such as net solar radiation were also discussed. The results of this study indicated that: (1) increasing temperature was observed mainly in the northeast and northwest China; (2) different behaviors were identified in the changes of maximum and minimum temperature respectively. Maximum temperature seemed to be more influenced by urbanization, which could be due to increasing urban albedo, aerosol, and air pollutions in the urbanized areas. Minimum temperature was subject to influences of variations of net solar radiation; (3) not significant increasing and even decreasing temperature extremes in the Yangtze River basin and the regions south to the Yangtze River basin could be the consequences of higher relative humidity as a result of increasing precipitation; (4) the entire China was dominated by increasing minimum temperature. Thus, we can say that the warming process of China was reflected mainly by increasing minimum temperature. In addition, consistently increasing temperature was found in the upper reaches of the Yellow River basin, the Yangtze River basin, which have the potential to enhance the melting of permafrost in these areas. This may trigger new ecological problems and raise new challenges for the river basin scale water resource management.

  7. Ubiquitous Nature of Distal Athero/Thromboembolic Events during Lower Extremity Atherectomy Procedures Involving the Superficial Femoral Artery

    Science.gov (United States)

    Wasty, Najam; Khakwani, M. Z.; Kotev, Spas; Boiangiu, Catalin; Hasan, Omar; Anna, Manjusha; Tayal, Rajiv; Kaid, Khalil; Baker, Gail; Cohen, Marc

    2016-01-01

    This study aims to evaluate occurrence, size, composition, and clinical significance of embolized debris during superficial femoral artery atherectomy using all commercially available atherectomy devices. Distal athero/thromboembolic events (DATE) are a universal phenomenon in lower extremity atherectomy procedures (LEAPs) due to the sheer volume of atheroma and the thrombus burden in peripheral arterial disease. Some of these events can be clinically significant. We prospectively gathered clinical and histopathological data on all commercially available atherectomy devices by using embolic protection devices (EPD) in every case. After intervention, the contents of EPD were examined both microscopically and macroscopically. Data from 59 consecutive patients undergoing LEAP were analyzed. DATE occurred 100% of the time. The composition of particulate debris varied with the device used. Grossly visible agglomerated debris was captured by the filter in the majority of patients 54/59 (91.5%). Clinically significant debris, defined by the Preventing Lower Extremity Distal Embolization Using Embolic Filter Protection registry as particle diameter > 0.2 cm, was found in 33/59 (56%) patients. The size of captured debris particles ranged from 0.1 to 2.4 mm. While DATE occurred in all patients, clinically significant DATE occurred in 56% patients undergoing LEAP regardless of the atherectomy device. In spite of a large fraction of the clinically significant debris occurring on our routine dual antiplatelet regimen, no patient suffered an amputation. Although DATE was prevented by the use of EPD in all 59 cases, more data are needed to determine whether the use of EPD translates into a long-term clinical benefit. Use of EPD and optimal thromboprophylaxis should be considered in patients, especially in the setting of compromised distal runoff. PMID:27867291

  8. A Natural Mutation Involving both Pathogenicity and Perithecium Formation in the Fusarium graminearum Species Complex

    Directory of Open Access Journals (Sweden)

    Haruhisha Suga

    2016-12-01

    Full Text Available Members of the Fusarium graminearum species complex (Fg complex or FGSC are the primary pathogens causing Fusarium head blight in wheat and barley worldwide. A natural pathogenicity mutant (strain 0225022 was found in a sample of the Fg complex collected in Japan. The mutant strain did not induce symptoms in wheat spikes beyond the point of inoculation, and did not form perithecia. No segregation of phenotypic deficiencies occurred in the progenies of a cross between the mutant and a fully pathogenic wild-type strain, which suggested that a single genetic locus controlled both traits. The locus was mapped to chromosome 2 by using sequence-tagged markers; and a deletion of ∼3 kb was detected in the mapped region of the mutant strain. The wild-type strain contains the FGSG_02810 gene, encoding a putative glycosylphosphatidylinositol anchor protein, in this region. The contribution of FGSG_02810 to pathogenicity and perithecium formation was confirmed by complementation in the mutant strain using gene transfer, and by gene disruption in the wild-type strain.

  9. Theoretical study of the binding nature of glassy carbon with nickel(II) phthalocyanine complexes

    International Nuclear Information System (INIS)

    Cortez, Luis; Berrios, Cristhian; Yanez, Mauricio; Cardenas-Jiron, Gloria I.

    2009-01-01

    A theoretical study at the semiempirical RHF/PM3(tm) level (tm: transition metal) of the binding nature between a glassy carbon (GC) cluster and a nickel(II) complex (nickel(II) phthalocyanine NiPc, nickel(II) tetrasulphophthalocyanine NiTSPc) was performed. Three types of interactions for GC...NiPc (NiTSPc) were studied: (a) through an oxo (O) bridge, (b) through an hydroxo (OH) bridge, and (c) non-bridge. One layer (NiPc, NiTSPc) and two layers (NiPc...NiPc) of complex were considered. The binding energy calculated showed that in both cases NiPc and NiTSPc, the oxo structures are more stable than the hydroxo ones, and than the non-bridge systems. Charge analysis (NAO) predicted that GC gained more electrons in an oxo structure than in the analogues hydroxo. The theoretical results showed an agreement with the experimental data available, an oxo binding between GC and a nickel complex (NiPc, NiTSPc) in aqueous alkaline solutions is formed.

  10. Theoretical study of the binding nature of glassy carbon with nickel(II) phthalocyanine complexes

    Energy Technology Data Exchange (ETDEWEB)

    Cortez, Luis [Laboratorio de Quimica Teorica, Facultad de Quimica y Biologia, Universidad de Santiago de Chile (USACH), Casilla 40, Correo 33, Santiago (Chile); Berrios, Cristhian [Laboratorio de Electrocatalisis, Facultad de Quimica y Biologia, Universidad de Santiago de Chile (USACH), Casilla 40, Correo 33, Santiago (Chile); Yanez, Mauricio [Laboratorio de Recursos Renovables, Centro de Biotecnologia, Universidad de Concepcion, Casilla-160 C, Concepcion (Chile); Cardenas-Jiron, Gloria I., E-mail: gloria.cardenas@usach.cl [Laboratorio de Quimica Teorica, Facultad de Quimica y Biologia, Universidad de Santiago de Chile (USACH), Casilla 40, Correo 33, Santiago (Chile)

    2009-11-26

    A theoretical study at the semiempirical RHF/PM3(tm) level (tm: transition metal) of the binding nature between a glassy carbon (GC) cluster and a nickel(II) complex (nickel(II) phthalocyanine NiPc, nickel(II) tetrasulphophthalocyanine NiTSPc) was performed. Three types of interactions for GC...NiPc (NiTSPc) were studied: (a) through an oxo (O) bridge, (b) through an hydroxo (OH) bridge, and (c) non-bridge. One layer (NiPc, NiTSPc) and two layers (NiPc...NiPc) of complex were considered. The binding energy calculated showed that in both cases NiPc and NiTSPc, the oxo structures are more stable than the hydroxo ones, and than the non-bridge systems. Charge analysis (NAO) predicted that GC gained more electrons in an oxo structure than in the analogues hydroxo. The theoretical results showed an agreement with the experimental data available, an oxo binding between GC and a nickel complex (NiPc, NiTSPc) in aqueous alkaline solutions is formed.

  11. Predictability problems of global change as seen through natural systems complexity description. 2. Approach

    Directory of Open Access Journals (Sweden)

    Vladimir V. Kozoderov

    1998-01-01

    Full Text Available Developing the general statements of the proposed global change theory, outlined in Part 1 of the publication, Kolmogorov's probability space is used to study properties of information measures (unconditional, joint and conditional entropies, information divergence, mutual information, etc.. Sets of elementary events, the specified algebra of their sub-sets and probability measures for the algebra are composite parts of the space. The information measures are analyzed using the mathematical expectance operator and the adequacy between an additive function of sets and their equivalents in the form of the measures. As a result, explanations are given to multispectral satellite imagery visualization procedures using Markov's chains of random variables represented by pixels of the imagery. The proposed formalism of the information measures application enables to describe the natural targets complexity by syntactically governing probabilities. Asserted as that of signal/noise ratios finding for anomalies of natural processes, the predictability problem is solved by analyses of temporal data sets of related measurements for key regions and their background within contextually coherent structures of natural targets and between particular boundaries of the structures.

  12. Correlation of mitochondrial protein expression in complexes I to V with natural and induced forms of canine idiopathic dilated cardiomyopathy.

    Science.gov (United States)

    Lopes, Rosana; Solter, Philip F; Sisson, D David; Oyama, Mark A; Prosek, Robert

    2006-06-01

    To identify qualitative and quantitative differences in cardiac mitochondrial protein expression in complexes I to V between healthy dogs and dogs with natural or induced dilated cardiomyopathy (DCM). Left ventricle samples were obtained from 7 healthy dogs, 7 Doberman Pinschers with naturally occurring DCM, and 7 dogs with DCM induced by rapid right ventricular pacing. Fresh and frozen mitochondrial fractions were isolated from the left ventricular free wall and analyzed by 2-dimensional electrophoresis. Protein spots that increased or decreased in density by 2-fold or greater between groups were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry or quadrupole selecting, quadrupole collision cell, time-of-flight mass spectrometry. A total of 22 altered mitochondrial proteins were identified in complexes I to V. Ten and 12 were found in complex I and complexes II to V, respectively. Five were mitochondrial encoded, and 17 were nuclear encoded. Most altered mitochondrial proteins in tissue specimens from dogs with naturally occurring DCM were associated with complexes I and V, whereas in tissue specimens from dogs subjected to rapid ventricular pacing, complexes I and IV were more affected. In the experimentally induced form of DCM, only nuclear-encoded subunits were changed in complex I. In both disease groups, the 22-kd subunit was downregulated. Natural and induced forms of DCM resulted in altered mitochondrial protein expression in complexes I to V. However, subcellular differences between the experimental and naturally occurring forms of DCM may exist.

  13. Operation modes research of liquefied natural gas storages as a part of the ground complexes equipment

    Directory of Open Access Journals (Sweden)

    N. S. Korolev

    2014-01-01

    Full Text Available The use of the Liquefied Natural Gas (LNG in the space-rocket equipment is motivated by some advantages. That is why a lot of tests and works are actively carried out now on rocket engines using liquefied natural gas.To provide the engine tests and subsequent rocket complex operation a creation of LNG storages is demanded as a part of ground processing equipment and support for their safe operation conditions.One of LNG danger factor is its low boiling temperature, and also changing the condition, density and LNG boiling temperature at storage due to evaporation of light component, namely methane. At refill of the storages having fuel remains with a new LNG portion these factors can lead to formation of the stratified macro-layers and cause a mode of the intensive mixing that is called "rollover", with almost instant evaporation of LNG big mass and sharp pressure boost, capable to result in the storage distraction with catastrophic effects.The work objectives are formulated such as a technique development for forecasting of the LNG parameters in operating storages including the rollover mode, a comparison of calculated results of the LNG parameters with the experimental data, and a definition of possible recommendations for safe operation of LNG storages as a part of the ground complexes equipment.The paper reviews 12 publications concerning the issues and proceeding processes at operation of LNG storages, including the rollover mode.To verify the reliability of process simulation results in the LNG, represented in models by the binary methane-ethane mixture the calculated values have been compared with the experimental data for a LNG storage mode in the reservoir of a ground test complex.The reliability of developed models of the heat-mass-exchange processes in stratified on density and temperature in LNG storage with emergence of conditions for the rollover mode has been verified by comparing the settlement characteristics to the published

  14. Biological effects of several extreme space flight factors (acceleration, magnetically activated water) on mouse natural or modified radiosensitivity

    International Nuclear Information System (INIS)

    Datsov, E.R.

    1979-01-01

    Irradiated and Adeturon-protected mice were used to assess biological effects of several static (magnetically-activated water - MW) and dynamic (acceleration) factors of space flight. The study shows that increased gravitation, 20 G, 5 min, generated by a small radius centrifuge, increases static ability to work, while the number of peripheral blood cells decreases. Continuous exposure of mice to MW induces a decrease in dynamic ability to work, in comparison with the physiological controls, without substantial changes in other indices. Extreme factors in space flight (acceleration MW, radiation, radiation protector), alone or in combination, decrease the animal's growth rate. After administration of 200 mg/kg Adeturone, mouse dynamic ability to work increases, while its capabilities for adaptation and training are lowered, and pronounced leucocytosis is observed. MW, acceleration, or Adeturone pre-treatment of mice increases their survival and dynamic ability to work, following exposure to 600 R, when compared to irradiated animals, but decreases their capabilities for adaptation and training. Acceleration and Adeturone protect peripheral blood from radiation injury, while MW alone intensifies radiation cytopenia. Irradiation does not significantly modify the static ability to work, upon preceding exposure to MW or acceleration. In this case, Adeturone exerts protective effect. ME and Adeturone combined action results in increased survival rate and mean duration of life of irradiated animals, as compared to their single administration. Acceleration reduces MW, Adeturone and MW + Adeturone effect on survival. Peripheral blood parameters do not correlate with survival rates. Combined pre-treatment with two or three of the factors studied increases dynamic ability to work following irradiation, and in many cases the static ability as well. The combination of Adeturone and MW was the only one with negative effect on the static ability to work. (A.B.)

  15. The nature of extreme emission line galaxies at z = 1-2: kinematics and metallicities from near-infrared spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Maseda, Michael V.; Van der Wel, Arjen; Rix, Hans-Walter; Da Cunha, Elisabete; Meidt, Sharon E. [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Pacifici, Camilla [Yonsei University Observatory, Yonsei University, Seoul 120-749 (Korea, Republic of); Momcheva, Ivelina; Van Dokkum, Pieter; Nelson, Erica J. [Department of Astronomy, Yale University, New Haven, CT 06520 (United States); Brammer, Gabriel B.; Ferguson, Henry C.; Koekemoer, Anton M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Franx, Marijn; Fumagalli, Mattia [Leiden Observatory, Leiden University, Leiden (Netherlands); Bell, Eric F. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Förster-Schreiber, Natascha M. [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching (Germany); Koo, David C. [UCO/Lick Observatory and Department of Astronomy and Astrophysics, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Lundgren, Britt F. [Department of Astronomy, University of Wisconsin, 475 North Charter Street, Madison, WI 53706 (United States); Marchesini, Danilo [Physics and Astronomy Department, Tufts University, Robinson Hall, Room 257, Medford, MA 02155 (United States); Patel, Shannon G., E-mail: maseda@mpia.de [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); and others

    2014-08-10

    We present near-infrared spectroscopy of a sample of 22 Extreme Emission Line Galaxies at redshifts 1.3 < z < 2.3, confirming that these are low-mass (M{sub *} = 10{sup 8}-10{sup 9} M{sub ☉}) galaxies undergoing intense starburst episodes (M{sub *}/SFR ∼ 10-100 Myr). The sample is selected by [O III] or Hα emission line flux and equivalent width using near-infrared grism spectroscopy from the 3D-HST survey. High-resolution NIR spectroscopy is obtained with LBT/LUCI and VLT/X-SHOOTER. The [O III]/Hβ line ratio is high (≳ 5) and [N II]/Hα is always significantly below unity, which suggests a low gas-phase metallicity. We are able to determine gas-phase metallicities for seven of our objects using various strong-line methods, with values in the range 0.05-0.30 Z{sub ☉} and with a median of 0.15 Z{sub ☉}; for three of these objects we detect [O III] λ4363, which allows for a direct constraint on the metallicity. The velocity dispersion, as measured from the nebular emission lines, is typically ∼50 km s{sup –1}. Combined with the observed star-forming activity, the Jeans and Toomre stability criteria imply that the gas fraction must be large (f{sub gas} ≳ 2/3), consistent with the difference between our dynamical and stellar mass estimates. The implied gas depletion timescale (several hundred Myr) is substantially longer than the inferred mass-weighted ages (∼50 Myr), which further supports the emerging picture that most stars in low-mass galaxies form in short, intense bursts of star formation.

  16. Extremely Low Frequency-Magnetic Fields (ELF-EMF) occupational exposure and natural killer activity in peripheral blood lymphocytes

    International Nuclear Information System (INIS)

    Gobba, Fabriziomaria; Bargellini, Annalisa; Scaringi, Meri; Bravo, Giulia; Borella, Paola

    2009-01-01

    Extremely Low Frequency-Magnetic Fields (ELF-MF) are possible carcinogens to humans and some data suggest that they can act as promoters or progressors. Since NK cells play a major role in the control of cancer development, an adverse effect on ELF-MF on NK function has been hypothesized. We examined NK activity in 52 workers exposed to different levels of ELF-MF in various activities. Individual exposure was monitored during 3 complete work-shifts using personal dosimeters. Environmental exposure was also monitored. ELF-MF levels in the workers were expressed as Time-Weighted Average (TWA) values. NK activity was measured in peripheral blood lymphocytes (PBL). In the whole group the median occupational TWA was 0.21 μT. According to the TWA levels, workers were classified as low exposed (26 subjects, TWA ≤ 0.2 μT) and higher exposed workers (26 subjects; TWA > 0.2 μT). In higher exposed workers, we observed a trend to reduce NK activity compared to low exposed, but the difference was not significant. Then we selected a subgroup of highest exposed workers (12 subjects; TWA > 1 μT); no difference was observed between low and highest exposed subjects in the main personal variables. Considering both E:T ratios from 12:1 to 50:1 and Lytic Units, a significant reduction in NK activity was observed in the highest exposed workers compared to the low exposed. Multivariate analysis showed a significant negative correlation between exposure and LU, while no correlation was evidenced with other personal characteristics. ELF-MF are considered possible carcinogens, and existing data suggest that they can act as promoters. Due to the role of NK activity in host defence against cancer, the results obtained in this study in workers exposed to ELF-MF levels exceeding 1 μT are in agreement with this hypothesis, and support the need for further investigation in this field

  17. Toward Design Guidelines for Stream Restoration Structures: Measuring and Modeling Unsteady Turbulent Flows in Natural Streams with Complex Hydraulic Structures

    Science.gov (United States)

    Lightbody, A.; Sotiropoulos, F.; Kang, S.; Diplas, P.

    2009-12-01

    Despite their widespread application to prevent lateral river migration, stabilize banks, and promote aquatic habitat, shallow transverse flow training structures such as rock vanes and stream barbs lack quantitative design guidelines. Due to the lack of fundamental knowledge about the interaction of the flow field with the sediment bed, existing engineering standards are typically based on various subjective criteria or on cross-sectionally-averaged shear stresses rather than local values. Here, we examine the performance and stability of in-stream structures within a field-scale single-threaded sand-bed meandering stream channel in the newly developed Outdoor StreamLab (OSL) at the St. Anthony Falls Laboratory (SAFL). Before and after the installation of a rock vane along the outer bank of the middle meander bend, high-resolution topography data were obtained for the entire 50-m-long reach at 1-cm spatial scale in the horizontal and sub-millimeter spatial scale in the vertical. In addition, detailed measurements of flow and turbulence were obtained using acoustic Doppler velocimetry at twelve cross-sections focused on the vicinity of the structure. Measurements were repeated at a range of extreme events, including in-bank flows with an approximate flow rate of 44 L/s (1.4 cfs) and bankfull floods with an approximate flow rate of 280 L/s (10 cfs). Under both flow rates, the structure reduced near-bank shear stresses and resulted in both a deeper thalweg and near-bank aggradation. The resulting comprehensive dataset has been used to validate a large eddy simulation carried out by SAFL’s computational fluid dynamics model, the Virtual StreamLab (VSL). This versatile computational framework is able to efficiently simulate 3D unsteady turbulent flows in natural streams with complex in-stream structures and as a result holds promise for the development of much-needed quantitative design guidelines.

  18. Data for effects of lanthanum complex on the thermo-oxidative aging of natural rubber

    Directory of Open Access Journals (Sweden)

    Wei Zheng

    2015-12-01

    Full Text Available Novel mixed antioxidants composed of antioxidant IPPD and lanthanum (La complex were added as a filler to form natural rubber (NR composites. By mechanical testing, Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR and thermogravimetric analysis (TGA, a string of data, including the mechanical properties, the variation of internal groups and the thermal and thermo-oxidative decompositions of NR, was presented in this data article. The data accompanying its research article [1] studied the thermo-oxidative aging properties of NR in detail. The density function theoretical (DFT calculations were also used as an assistant to study the thermo-oxidative aging mechanism of NR. The data revealed that this new rare-earth antioxidant could indeed enhance the thermo-oxidative aging resistance of NR, which is associated with its different function mechanism from that of the pure antioxidant IPPD.

  19. Data for effects of lanthanum complex on the thermo-oxidative aging of natural rubber.

    Science.gov (United States)

    Zheng, Wei; Liu, Li; Zhao, Xiuying; He, Jingwei; Wang, Ao; Chan, Tung W; Wu, Sizhu

    2015-12-01

    Novel mixed antioxidants composed of antioxidant IPPD and lanthanum (La) complex were added as a filler to form natural rubber (NR) composites. By mechanical testing, Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) and thermogravimetric analysis (TGA), a string of data, including the mechanical properties, the variation of internal groups and the thermal and thermo-oxidative decompositions of NR, was presented in this data article. The data accompanying its research article [1] studied the thermo-oxidative aging properties of NR in detail. The density function theoretical (DFT) calculations were also used as an assistant to study the thermo-oxidative aging mechanism of NR. The data revealed that this new rare-earth antioxidant could indeed enhance the thermo-oxidative aging resistance of NR, which is associated with its different function mechanism from that of the pure antioxidant IPPD.

  20. Employing the Hilbert-Huang Transform to analyze observed natural complex signals: Calm wind meandering cases

    Science.gov (United States)

    Martins, Luis Gustavo Nogueira; Stefanello, Michel Baptistella; Degrazia, Gervásio Annes; Acevedo, Otávio Costa; Puhales, Franciano Scremin; Demarco, Giuliano; Mortarini, Luca; Anfossi, Domenico; Roberti, Débora Regina; Costa, Felipe Denardin; Maldaner, Silvana

    2016-11-01

    In this study we analyze natural complex signals employing the Hilbert-Huang spectral analysis. Specifically, low wind meandering meteorological data are decomposed into turbulent and non turbulent components. These non turbulent movements, responsible for the absence of a preferential direction of the horizontal wind, provoke negative lobes in the meandering autocorrelation functions. The meandering characteristic time scales (meandering periods) are determined from the spectral peak provided by the Hilbert-Huang marginal spectrum. The magnitudes of the temperature and horizontal wind meandering period obtained agree with the results found from the best fit of the heuristic meandering autocorrelation functions. Therefore, the new method represents a new procedure to evaluate meandering periods that does not employ mathematical expressions to represent observed meandering autocorrelation functions.

  1. Colour and luminance contrasts predict the human detection of natural stimuli in complex visual environments.

    Science.gov (United States)

    White, Thomas E; Rojas, Bibiana; Mappes, Johanna; Rautiala, Petri; Kemp, Darrell J

    2017-09-01

    Much of what we know about human colour perception has come from psychophysical studies conducted in tightly-controlled laboratory settings. An enduring challenge, however, lies in extrapolating this knowledge to the noisy conditions that characterize our actual visual experience. Here we combine statistical models of visual perception with empirical data to explore how chromatic (hue/saturation) and achromatic (luminant) information underpins the detection and classification of stimuli in a complex forest environment. The data best support a simple linear model of stimulus detection as an additive function of both luminance and saturation contrast. The strength of each predictor is modest yet consistent across gross variation in viewing conditions, which accords with expectation based upon general primate psychophysics. Our findings implicate simple visual cues in the guidance of perception amidst natural noise, and highlight the potential for informing human vision via a fusion between psychophysical modelling and real-world behaviour. © 2017 The Author(s).

  2. Data for effects of lanthanum complex on the thermo-oxidative aging of natural rubber

    Science.gov (United States)

    Zheng, Wei; Liu, Li; Zhao, Xiuying; He, Jingwei; Wang, Ao; Chan, Tung W.; Wu, Sizhu

    2015-01-01

    Novel mixed antioxidants composed of antioxidant IPPD and lanthanum (La) complex were added as a filler to form natural rubber (NR) composites. By mechanical testing, Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) and thermogravimetric analysis (TGA), a string of data, including the mechanical properties, the variation of internal groups and the thermal and thermo-oxidative decompositions of NR, was presented in this data article. The data accompanying its research article [1] studied the thermo-oxidative aging properties of NR in detail. The density function theoretical (DFT) calculations were also used as an assistant to study the thermo-oxidative aging mechanism of NR. The data revealed that this new rare-earth antioxidant could indeed enhance the thermo-oxidative aging resistance of NR, which is associated with its different function mechanism from that of the pure antioxidant IPPD. PMID:26693513

  3. Small saccades and image complexity during free viewing of natural images in schizophrenia.

    Directory of Open Access Journals (Sweden)

    Jose Ignacio Egaña

    2013-05-01

    Full Text Available In schizophrenia, patients display dysfunctions during the execution of simple visual tasks such as anti-saccade or smooth pursuit. In more ecological scenarios, such as free viewing of natural images, patients appear to make fewer and longer visual fixations and display shorter scanpaths. It is not clear whether these measurements reflect alterations in their proficiency to perform basic eye movements, such as saccades and fixations, or are related to high-level mechanisms, such as exploration or attention. We utilized free exploration of natural images of different complexities as a model of an ecological context where normally operative mechanisms of visual control can be accurately measured. We quantified visual exploration as Euclidean distance, scanpaths, saccades and visual fixation, using the standard SR-Research eye tracker algorithm (SR. We then compared this result with a computation that includes microsaccades (EM. We evaluated 8 schizophrenia patients and corresponding healthy controls (HC. Next, we tested whether the decrement in the number of saccades and fixations, as well as their increment in duration reported previously in schizophrenia patients, resulted from the increasing occurrence of undetected microsaccades. We found that when utilizing the standard SR algorithm, patients displayed shorter scanpaths as well as fewer and shorter saccades and fixations. When we employed the EM algorithm, the differences in these parameters between patients and HC were no longer significant. On the other hand, we found that image complexity plays an important role in exploratory behaviors, demonstrating that this factor explains most of differences between eye-movement behaviors in schizophrenia patients. These results help elucidate the mechanisms of visual motor control that are affected in schizophrenia and contribute to the finding of adequate markers for diagnosis and treatment for this condition.

  4. Simulation of complex fracture networks influenced by natural fractures in shale gas reservoir

    Directory of Open Access Journals (Sweden)

    Zhao Jinzhou

    2014-10-01

    Full Text Available When hydraulic fractures intersect with natural fractures, the geometry and complexity of a fracture network are determined by the initiation and propagation pattern which is affected by a number of factors. Based on the fracture mechanics, the criterion for initiation and propagation of a fracture was introduced to analyze the tendency of a propagating angle and factors affecting propagating pressure. On this basis, a mathematic model with a complex fracture network was established to investigate how the fracture network form changes with different parameters, including rock mechanics, in-situ stress distribution, fracture properties, and frac treatment parameters. The solving process of this model was accelerated by classifying the calculation nodes on the extending direction of the fracture by equal pressure gradients, and solving the geometrical parameters prior to the iteration fitting flow distribution. With the initiation and propagation criterion as the bases for the propagation of branch fractures, this method decreased the iteration times through eliminating the fitting of the fracture length in conventional 3D fracture simulation. The simulation results indicated that the formation with abundant natural fractures and smaller in-situ stress difference is sufficient conditions for fracture network development. If the pressure in the hydraulic fractures can be kept at a high level by temporary sealing or diversion, the branch fractures will propagate further with minor curvature radius, thus enlarging the reservoir stimulation area. The simulated shape of fracture network can be well matched with the field microseismic mapping in data point range and distribution density, validating the accuracy of this model.

  5. A Naturally Occurring Antioxidant Complex from Unripe Grapes: The Case of Sangiovese (v. Vitis vinifera

    Directory of Open Access Journals (Sweden)

    Giovanna Fia

    2018-02-01

    Full Text Available The wine industry is well known for its production of a large amount of wastes and by-products. Among them, unripe grapes from thinning operations are an undervalued by-product. Grapes are an interesting source of natural antioxidants such as flavonoids, non-flavonoids and stilbenes. A potential strategy to exploit unripe grapes was investigated in this study. Juice from unripe grapes, v. Sangiovese, was obtained by an innovative technique of solid-liquid extraction without the use of solvents. The juice was dried by a spray-drying technique with the addition of arabic gum as support to obtain powder; juice and powder were characterized for antioxidant activity, phenolic concentration and profile. Phenolic acids, flavonols, flava-3-ols, procyanidins and resveratrol were detected in the juice and powder. The powder was used as anti-browning additive in white wine to test the potential re-use of the unripe grapes in the wine industry. The results indicated that the antioxidant complex from unripe grapes contributed to increasing the anti-browning capacity of white wine. Other applications, such as food and nutraceutical products development, can be considered for the antioxidant complex extracted from unripe grapes. In conclusion, the method proposed in this study may contribute to the exploitation of unripe grapes as a by-product of the winemaking process.

  6. A robust and efficient finite volume scheme for the discretization of diffusive flux on extremely skewed meshes in complex geometries

    Science.gov (United States)

    Traoré, Philippe; Ahipo, Yves Marcel; Louste, Christophe

    2009-08-01

    In this paper an improved finite volume scheme to discretize diffusive flux on a non-orthogonal mesh is proposed. This approach, based on an iterative technique initially suggested by Khosla [P.K. Khosla, S.G. Rubin, A diagonally dominant second-order accurate implicit scheme, Computers and Fluids 2 (1974) 207-209] and known as deferred correction, has been intensively utilized by Muzaferija [S. Muzaferija, Adaptative finite volume method for flow prediction using unstructured meshes and multigrid approach, Ph.D. Thesis, Imperial College, 1994] and later Fergizer and Peric [J.H. Fergizer, M. Peric, Computational Methods for Fluid Dynamics, Springer, 2002] to deal with the non-orthogonality of the control volumes. Using a more suitable decomposition of the normal gradient, our scheme gives accurate solutions in geometries where the basic idea of Muzaferija fails. First the performances of both schemes are compared for a Poisson problem solved in quadrangular domains where control volumes are increasingly skewed in order to test their robustness and efficiency. It is shown that convergence properties and the accuracy order of the solution are not degraded even on extremely skewed mesh. Next, the very stable behavior of the method is successfully demonstrated on a randomly distorted grid as well as on an anisotropically distorted one. Finally we compare the solution obtained for quadrilateral control volumes to the ones obtained with a finite element code and with an unstructured version of our finite volume code for triangular control volumes. No differences can be observed between the different solutions, which demonstrates the effectiveness of our approach.

  7. Synergistic microbial consortium for bioenergy generation from complex natural energy sources.

    Science.gov (United States)

    Wang, Victor Bochuan; Yam, Joey Kuok Hoong; Chua, Song-Lin; Zhang, Qichun; Cao, Bin; Chye, Joachim Loo Say; Yang, Liang

    2014-01-01

    Microbial species have evolved diverse mechanisms for utilization of complex carbon sources. Proper combination of targeted species can affect bioenergy production from natural waste products. Here, we established a stable microbial consortium with Escherichia coli and Shewanella oneidensis in microbial fuel cells (MFCs) to produce bioenergy from an abundant natural energy source, in the form of the sarcocarp harvested from coconuts. This component is mostly discarded as waste. However, through its usage as a feedstock for MFCs to produce useful energy in this study, the sarcocarp can be utilized meaningfully. The monospecies S. oneidensis system was able to generate bioenergy in a short experimental time frame while the monospecies E. coli system generated significantly less bioenergy. A combination of E. coli and S. oneidensis in the ratio of 1:9 (v:v) significantly enhanced the experimental time frame and magnitude of bioenergy generation. The synergistic effect is suggested to arise from E. coli and S. oneidensis utilizing different nutrients as electron donors and effect of flavins secreted by S. oneidensis. Confocal images confirmed the presence of biofilms and point towards their importance in generating bioenergy in MFCs.

  8. Wastewater treatment from heavy metal ions using nanoactivated complexes of natural zeolite and diatomite

    Directory of Open Access Journals (Sweden)

    Malkin Polad

    2018-04-01

    Full Text Available Despite the wide practical use of sorption methods and complexones in treatment of industrial wastewater, some problems are still to be solved in this field. These are the most significant: insufficient sorption capacity of materials, lack of reliable methods for regenerating sorbents and resource-saving ecology friendly treatment technologies with the use of sorbents as well as methods of utilization of heavy metals from waste by complex formation. An important factor affecting the behavior of heavy metals in the soil is the medium acidity. With a neutral and slightly alkaline reaction of the medium, hardly soluble compounds are formed: hydroxides, sulphides, phosphates, carbonates, and oxalates of heavy metals. When acidity increases the reverse process runs in the soil: hardly soluble compounds become more mobile, while mobility of many heavy metals increases. However, the effect of soil acidity on mobility of heavy metals is ambiguous. Although mobility of many heavy metals decreases with increasing pH of the medium (for example, Fe, Mn, Zn, Co, etc., there are a number of metals whose mobility increases with soil neutralization. These include molybdenum and chromium, which are able to form soluble salts in a weak ly acidic and alkaline medium. In addition, heavy metals such as mercury and cadmium are able to maintain mobility in an alkaline medium through formation of complex compounds with organic matter in soils. Heavy metals interact with a solid phase of the soil by mechanisms of specific and nonspecific adsorption. In this article, a technique of wastewater treatment from heavy metal ions using nanoactivated complexes of natural zeolite and diatomite is proposed. This technique can reduce significant costs in preparation of raw materials and subsequent chemical modification of them. Technological solutions aimed at disposal and recycling of industrial wastewater have been proposed. These solutions make it possible to obtain the water

  9. Effect of second-sphere cation nature on the character of IR spectra of molybdeum(4, 5) cyanide complexes

    International Nuclear Information System (INIS)

    Zubritskaya, D.I.; Semenishin, D.I.; Vretsena, N.B.; Chernyak, B.I.

    1989-01-01

    The effect of nature of second-sphere cations on IR spectra of molybdeum (4, 5) cyanide complexes is studied. It is found that the increase in the first ionization potential (radius decrease) brings about the increase in the frequency of valent variations ν (CN). This proves the possibility of formation of bridge bonds Mo-CN-M in the compounds (M-alkali, alkaline earth or rare earth metal, Cs, Y). The conclusion is made on a considerable effect of the nature of second-sphere cations and oxidation degree of complexing agent atoms on the nature of IR spectra of octacyanomolybdates (4, 5)

  10. The globular cluster system of NGC 1316. IV. Nature of the star cluster complex SH2

    Science.gov (United States)

    Richtler, T.; Husemann, B.; Hilker, M.; Puzia, T. H.; Bresolin, F.; Gómez, M.

    2017-05-01

    Context. The light of the merger remnant NGC 1316 (Fornax A) is dominated by old and intermediate-age stars. The only sign of current star formation in this big galaxy is the Hii region SH2, an isolated star cluster complex with a ring-like morphology and an estimated age of 0.1 Gyr at a galactocentric distance of about 35 kpc. A nearby intermediate-age globular cluster, surrounded by weak line emission and a few more young star clusters, is kinematically associated. The origin of this complex is enigmatic. Aims: We want to investigate the nature of this star cluster complex. The nebular emission lines permit a metallicity determination which can discriminate between a dwarf galaxy or other possible precursors. Methods: We used the Integral Field Unit (IFU) of the VIMOS instrument at the Very Large Telescope of the European Southern Observatory in high dispersion mode to study the morphology, kinematics, and metallicity employing line maps, velocity maps, and line diagnostics of a few characteristic spectra. Results: The line ratios of different spectra vary, indicating highly structured Hii regions, but define a locus of uniform metallicity. The strong-line diagnostic diagrams and empirical calibrations point to a nearly solar or even super-solar oxygen abundance. The velocity dispersion of the gas is highest in the region offset from the bright clusters. Star formation may be active on a low level. There is evidence for a large-scale disk-like structure in the region of SH2, which would make the similar radial velocity of the nearby globular cluster easier to understand. Conclusions: The high metallicity does not fit to a dwarf galaxy as progenitor. We favour the scenario of a free-floating gaseous complex having its origin in the merger 2 Gyr ago. Over a long period the densities increased secularly until finally the threshold for star formation was reached. SH2 illustrates how massive star clusters can form outside starbursts and without a considerable field

  11. Complex and changing patterns of natural selection explain the evolution of the human hip.

    Science.gov (United States)

    Grabowski, Mark; Roseman, Charles C

    2015-08-01

    Causal explanations for the dramatic changes that occurred during the evolution of the human hip focus largely on selection for bipedal function and locomotor efficiency. These hypotheses rest on two critical assumptions. The first-that these anatomical changes served functional roles in bipedalism-has been supported in numerous analyses showing how postcranial changes likely affected locomotion. The second-that morphological changes that did play functional roles in bipedalism were the result of selection for that behavior-has not been previously explored and represents a major gap in our understanding of hominin hip evolution. Here we use evolutionary quantitative genetic models to test the hypothesis that strong directional selection on many individual aspects of morphology was responsible for the large differences observed across a sample of fossil hominin hips spanning the Plio-Pleistocene. Our approach uses covariance among traits and the differences between relatively complete fossils to estimate the net selection pressures that drove the major transitions in hominin hip evolution. Our findings show a complex and changing pattern of natural selection drove hominin hip evolution, and that many, but not all, traits hypothesized to play functional roles in bipedalism evolved as a direct result of natural selection. While the rate of evolutionary change for all transitions explored here does not exceed the amount expected if evolution was occurring solely through neutral processes, it was far above rates of evolution for morphological traits in other mammalian groups. Given that stasis is the norm in the mammalian fossil record, our results suggest that large shifts in the adaptive landscape drove hominin evolution. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Selective whole genome amplification for resequencing target microbial species from complex natural samples.

    Science.gov (United States)

    Leichty, Aaron R; Brisson, Dustin

    2014-10-01

    Population genomic analyses have demonstrated power to address major questions in evolutionary and molecular microbiology. Collecting populations of genomes is hindered in many microbial species by the absence of a cost effective and practical method to collect ample quantities of sufficiently pure genomic DNA for next-generation sequencing. Here we present a simple method to amplify genomes of a target microbial species present in a complex, natural sample. The selective whole genome amplification (SWGA) technique amplifies target genomes using nucleotide sequence motifs that are common in the target microbe genome, but rare in the background genomes, to prime the highly processive phi29 polymerase. SWGA thus selectively amplifies the target genome from samples in which it originally represented a minor fraction of the total DNA. The post-SWGA samples are enriched in target genomic DNA, which are ideal for population resequencing. We demonstrate the efficacy of SWGA using both laboratory-prepared mixtures of cultured microbes as well as a natural host-microbe association. Targeted amplification of Borrelia burgdorferi mixed with Escherichia coli at genome ratios of 1:2000 resulted in >10(5)-fold amplification of the target genomes with genomic extracts from Wolbachia pipientis-infected Drosophila melanogaster resulted in up to 70% of high-throughput resequencing reads mapping to the W. pipientis genome. By contrast, 2-9% of sequencing reads were derived from W. pipientis without prior amplification. The SWGA technique results in high sequencing coverage at a fraction of the sequencing effort, thus allowing population genomic studies at affordable costs. Copyright © 2014 by the Genetics Society of America.

  13. Wireless peripheral nerve stimulation for complex regional pain syndrome type I of the upper extremity: a case illustration introducing a novel technology.

    Science.gov (United States)

    Herschkowitz, Daniel; Kubias, Jana

    2018-04-13

    Complex regional pain syndrome (CRPS) is a debilitating painful disorder, cryptic in its pathophysiology and refractory condition with limited therapeutic options. Type I CRPS with its variable relationship to trauma has often no discernible fractures or nerve injuries and remains enigmatic in its response to conservative treatment as well as the other limited interventional therapies. Neuromodulation in the form of spinal cord and dorsal root ganglion stimulation (SCS, DRGS) has shown encouraging results, especially of causalgia or CRPS I of lower extremities. Upper extremity CRPS I is far more difficult. To report a case of upper extremity CRPS I treated by wireless peripheral nerve stimulation (WPNS) for its unique features and minimally invasive technique. The system does not involve implantation of battery or its connections. A 47 year old female patient presented with refractory CRPS I following a blunt trauma to her right forearm. As interventional treatment in the form of local anesthetics (Anesthesia of peripheral branches of radial nerve) and combined infusions of ketamine/lidocaine failed to provide any significant relief she opted for WPNS treatment. Based on the topographic distribution, two electrodes (Stimwave Leads: FR4A-RCV-A0 with tines, Generation 1 and FR4A-RCV-B0 with tines, Generation 1), were placed along the course of radial and median nerves under ultrasonography monitoring and guided by intraoperative stimulation. This procedure did not involve implantation of extension cables or the power source. At a frequency of 60 Hz and 300 μs the stimulation induced paresthesia along the distribution of the nerves. Therapeutic relief was observed with high frequency (HF) stimulation (HF 10 kHz/32 μs, 2.0 mA) reducing her pain from a visual analogue scale (VAS) score of 7-4 postoperatively. Three HF stimulations programs were provided at the time of discharge, as she improved in her sensory impairment to touch, pressure and temperature at her first

  14. Natural radionuclides in the Brazilian coast region: 1. Estuarine complex Cananeia-Iguape, Sao Paulo State

    Energy Technology Data Exchange (ETDEWEB)

    Franca, E.J. de; Ferreira, Fabiano S.; Silva Neto, Paulo C.; Farias, Emerson E.G. de; Figueira, Rubens C.L.; Ribeiro, Andreza P., E-mail: ejfranca@cnen.gov.br, E-mail: biologofabiano10@gmail.com, E-mail: ptpoli@yahoo.com.br, E-mail: emersonemiliano@yahoo.com.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2015-07-01

    Mangrove forests are of utmost important ecosystems for biogeochemical transport processes in a global scale because of the preferential transport via sediments and organic matter from continents to oceans. Such ecosystems are the richest biodiversity areas, in which bioaccumulation of chemical substances can be expected for some species, in this case, there is a lack of knowledge of natural radionuclides accumulation in mangrove vegetation. This work encompasses the first results obtained for the Estuarine Complex Cananeia-Iguape, a peculiar coast area of the Sao Paulo State, Brazil. In 2011, leaf samples of Rhyzophora mangle and Laguncularia racemosa trees with perimeter at the breast height higher than 15 cm were collected in the conservation unit Parque Estadual Ilha do Cardoso. Sample preparation consisted of leaf washing, oven-drying, milling in porcelain mortar at the particle size lower than 0.5 mm. Portions of 10 g were transferred to polyethylene vials of appropriate geometry for the analysis by high resolution gamma-ray spectrometry. Reference materials were analyzed together to evaluate the quality of the analytical procedure. K-40 was preferentially allocated in leaves. Some accumulation in leaves was noticed for Pb-210 and Ac-228 depending on the species, indicating differences of radionuclide distribution in the mangrove vegetation. (author)

  15. Safety assessment of complex engineered and natural systems: radioactive waste disposal

    International Nuclear Information System (INIS)

    McNeish, J.A.; Vallikat, V.; Atkins, J.; Balady, M.A.

    1997-01-01

    Evaluation of deep, geologic disposal of nuclear waste requires the probabilistic safety assessment of a complex system from the coupling of various processes and sub-systems, parameter and model uncertainties, spatial and temporal variabilities, and the multiplicity of designs and scenarios. Both the engineered and natural system are included in the evaluation. Each system has aspects with considerable uncertainty both in important parameters and in overall conceptual models. The study represented herein provides a probabilistic safety assessment of a potential respository system for multiple engineered barrier system (EBS) design and conceptual model configurations (CRWMS M and O, 1996a) and considers the effects of uncertainty on the overall results. The assessment is based on data and process models available at the time of the study and doesnt necessarily represent the current safety evaluation. In fact, the percolation flux through the repository system is now expected to be higher than the estimate used for this study. The potential effects of higher percolation fluxes are currently under study. The safety of the system was assessed for both 10,000 and 1,000,000 years. Use of alternative conceptual models also produced major improvement in safety. For example, use of a more realistic engineered system release model produced improvement of over an order of magnitude in safety. Alternative measurement locations for the safety assessment produced substantial increases in safety, through the results are based on uncertain dilution factors in the transporting groundwater. (Author)

  16. Formation of mercury sulfide from Hg(II)−thiolate complexes in natural organic matter

    Science.gov (United States)

    Alain Manceau,; Cyprien Lemouchi,; Mironel Enescu,; Anne-Claire Gaillot,; Martine Lanson,; Valerie Magnin,; Pieter Glatzel,; Poulin, Brett; Ryan, Joseph N.; Aiken, George R.; Isabelle Gautier-Lunea,; Kathryn L. Nagy,

    2015-01-01

    Methylmercury is the environmental form of neurotoxic mercury that is biomagnified in the food chain. Methylation rates are reduced when the metal is sequestered in crystalline mercury sulfides or bound to thiol groups in macromolecular natural organic matter. Mercury sulfide minerals are known to nucleate in anoxic zones, by reaction of the thiol-bound mercury with biogenic sulfide, but not in oxic environments. We present experimental evidence that mercury sulfide forms from thiol-bound mercury alone in aqueous dark systems in contact with air. The maximum amount of nanoparticulate mercury sulfide relative to thiol-bound mercury obtained by reacting dissolved mercury and soil organic matter matches that detected in the organic horizon of a contaminated soil situated downstream from Oak Ridge, TN, in the United States. The nearly identical ratios of the two forms of mercury in field and experimental systems suggest a common reaction mechanism for nucleating the mineral. We identified a chemical reaction mechanism that is thermodynamically favorable in which thiol-bound mercury polymerizes to mercury–sulfur clusters. The clusters form by elimination of sulfur from the thiol complexes via breaking of mercury–sulfur bonds as in an alkylation reaction. Addition of sulfide is not required. This nucleation mechanism provides one explanation for how mercury may be immobilized, and eventually sequestered, in oxygenated surface environments.

  17. Identification of naturally processed hepatitis C virus-derived major histocompatibility complex class I ligands.

    Directory of Open Access Journals (Sweden)

    Benno Wölk

    Full Text Available Fine mapping of human cytotoxic T lymphocyte (CTL responses against hepatitis C virus (HCV is based on external loading of target cells with synthetic peptides which are either derived from prediction algorithms or from overlapping peptide libraries. These strategies do not address putative host and viral mechanisms which may alter processing as well as presentation of CTL epitopes. Therefore, the aim of this proof-of-concept study was to identify naturally processed HCV-derived major histocompatibility complex (MHC class I ligands. To this end, continuous human cell lines were engineered to inducibly express HCV proteins and to constitutively express high levels of functional HLA-A2. These cell lines were recognized in an HLA-A2-restricted manner by HCV-specific CTLs. Ligands eluted from HLA-A2 molecules isolated from large-scale cultures of these cell lines were separated by high performance liquid chromatography and further analyzed by electrospray ionization quadrupole time of flight mass spectrometry (MS/tandem MS. These analyses allowed the identification of two HLA-A2-restricted epitopes derived from HCV nonstructural proteins (NS 3 and 5B (NS3₁₄₀₆₋₁₄₁₅ and NS5B₂₅₉₄₋₂₆₀₂. In conclusion, we describe a general strategy that may be useful to investigate HCV pathogenesis and may contribute to the development of preventive and therapeutic vaccines in the future.

  18. Natural radionuclides in the Brazilian coast region: 1. Estuarine complex Cananeia-Iguape, Sao Paulo State

    International Nuclear Information System (INIS)

    Franca, E.J. de; Ferreira, Fabiano S.; Silva Neto, Paulo C.; Farias, Emerson E.G. de; Figueira, Rubens C.L.; Ribeiro, Andreza P.

    2015-01-01

    Mangrove forests are of utmost important ecosystems for biogeochemical transport processes in a global scale because of the preferential transport via sediments and organic matter from continents to oceans. Such ecosystems are the richest biodiversity areas, in which bioaccumulation of chemical substances can be expected for some species, in this case, there is a lack of knowledge of natural radionuclides accumulation in mangrove vegetation. This work encompasses the first results obtained for the Estuarine Complex Cananeia-Iguape, a peculiar coast area of the Sao Paulo State, Brazil. In 2011, leaf samples of Rhyzophora mangle and Laguncularia racemosa trees with perimeter at the breast height higher than 15 cm were collected in the conservation unit Parque Estadual Ilha do Cardoso. Sample preparation consisted of leaf washing, oven-drying, milling in porcelain mortar at the particle size lower than 0.5 mm. Portions of 10 g were transferred to polyethylene vials of appropriate geometry for the analysis by high resolution gamma-ray spectrometry. Reference materials were analyzed together to evaluate the quality of the analytical procedure. K-40 was preferentially allocated in leaves. Some accumulation in leaves was noticed for Pb-210 and Ac-228 depending on the species, indicating differences of radionuclide distribution in the mangrove vegetation. (author)

  19. Energy and carbon emissions analysis and prediction of complex petrochemical systems based on an improved extreme learning machine integrated interpretative structural model

    International Nuclear Information System (INIS)

    Han, Yongming; Zhu, Qunxiong; Geng, Zhiqiang; Xu, Yuan

    2017-01-01

    Highlights: • The ELM integrated ISM (ISM-ELM) method is proposed. • The proposed method is more efficient and accurate than the ELM through the UCI data set. • Energy and carbon emissions analysis and prediction of petrochemical industries based ISM-ELM is obtained. • The proposed method is valid in improving energy efficiency and reducing carbon emissions of ethylene plants. - Abstract: Energy saving and carbon emissions reduction of the petrochemical industry are affected by many factors. Thus, it is difficult to analyze and optimize the energy of complex petrochemical systems accurately. This paper proposes an energy and carbon emissions analysis and prediction approach based on an improved extreme learning machine (ELM) integrated interpretative structural model (ISM) (ISM-ELM). ISM based the partial correlation coefficient is utilized to analyze key parameters that affect the energy and carbon emissions of the complex petrochemical system, and can denoise and reduce dimensions of data to decrease the training time and errors of the ELM prediction model. Meanwhile, in terms of the model accuracy and the training time, the robustness and effectiveness of the ISM-ELM model are better than the ELM through standard data sets from the University of California Irvine (UCI) repository. Moreover, a multi-inputs and single-output (MISO) model of energy and carbon emissions of complex ethylene systems is established based on the ISM-ELM. Finally, detailed analyses and simulations using the real ethylene plant data demonstrate the effectiveness of the ISM-ELM and can guide the improvement direction of energy saving and carbon emissions reduction in complex petrochemical systems.

  20. Uranium sorption to natural substrates-insights provided by isotope exchange, selective extraction and surface complexation modelling approaches

    International Nuclear Information System (INIS)

    Waite, T.D.; Payne T.E.; Davis, J.A.

    1993-01-01

    An extensive experimental program has been conducted over the last three years into the interaction of U(VI) with both single oxides and clays and complex natural substrates from the weathered zone in the vicinity of a uranium ore body in northern Australia. While iron oxides have frequently been considered to account for much of the uptake on such natural substrates, the results of laboratory open-quotes pH edgeclose quotes studies and of isotope exchange and selective extraction studies suggest that other phases must also play a significant role in controlling the partitioning of U(VI) between solid and solution phases. Supporting studies on kaolinite, the dominant clay in this system, provide insight into the most appropriate method of modelling the interaction of U(VI) with these natural substrates. The problems still remaining in adequately describing sorption of radionuclides and trace elements to complex natural substrates are discussed

  1. An approach for a complex assessment of the geo-ecological risk from natural disasters in a geographic region

    International Nuclear Information System (INIS)

    Zlateva, Plamena; Stoyanov, Krasimir

    2009-01-01

    The paper proposes an approach for a complex assessment of the geo-ecological risk of a certain geographic region on the basis of quantitative and qualitative datum about the potential natural disasters. A fuzzy logic model is designed. The type of the threats, consequences and interdependencies between infrastructure objects are taken into account. The geographic region is considered as a complex system of interconnected and mutually influencing elements. The expected damages are directly and/or indirectly connected with life quality deterioration. Keywords: Risk, Geo-ecological risk, Damages, Threats, Vulnerabilities, Natural disasters

  2. Optimization with Extremal Dynamics

    International Nuclear Information System (INIS)

    Boettcher, Stefan; Percus, Allon G.

    2001-01-01

    We explore a new general-purpose heuristic for finding high-quality solutions to hard discrete optimization problems. The method, called extremal optimization, is inspired by self-organized criticality, a concept introduced to describe emergent complexity in physical systems. Extremal optimization successively updates extremely undesirable variables of a single suboptimal solution, assigning them new, random values. Large fluctuations ensue, efficiently exploring many local optima. We use extremal optimization to elucidate the phase transition in the 3-coloring problem, and we provide independent confirmation of previously reported extrapolations for the ground-state energy of ±J spin glasses in d=3 and 4

  3. [Indiscriminate use of Latin name for natural Cordyceps sinensis insect-fungi complex and multiple Ophiocordyceps sinensis fungi].

    Science.gov (United States)

    Yao, Yi-Sang; Zhu, Jia-Shi

    2016-04-01

    Natural Cordyceps sinensis(Dongchongxiacao) is an insect-fungi complex containing multiple Ophiocordyceps sinensis(≡Cordyceps sinensis) fungi and dead body of larva of the family of Hepialidae. But natural C. sinensis and O. sinensis fungi use the same Latin name, resulting in uncertainty of the specific meaning, even disturbing the formulation and implementation of governmental policies and regulations, and influencing consumer psychology onthe market. This paper reviews the history and current status of the indiscriminate use of the Latin name O. sinensis for both the natural insect-fungi complex C. sinensis and O. sinensis fungi and lists the rename suggetions. Some scholars suggested using the term O. sinensis for the fungi and renaming the natural C. sinensis "Chinese cordyceps". Others suggested renaming the natural C. sinensis "Ophiocordyceps & Hepialidae". Both suggestions have not reached general consensus due to various academic concerns. This paper also reviews the exacerbation of the academic uncertainties when forcing implementing the 2011 Amsterdam Declaration "One Fungus=One Name" under the academic debate. Joint efforts of mycological, zoological and botany-TCM taxonomists and properly initiating the dispute systems offered by International Mycology Association may solve the debate on the indiscriminate use of the Latin name O.sinensis for the natural insect-fungi complex,the teleomorph and anamorph(s) of O. sinensis fungi. Copyright© by the Chinese Pharmaceutical Association.

  4. Online coupling of high-resolution chromatography with extreme UV photon activation tandem mass spectrometry: Application to the structural investigation of complex glycans by dissociative photoionization

    International Nuclear Information System (INIS)

    Ropartz, David; Giuliani, Alexandre; Fanuel, Mathieu; Hervé, Cécile; Czjzek, Mirjam; Rogniaux, Hélène

    2016-01-01

    The activation of ions by extreme-energy photons (XUV) produced by a synchrotron radiation beamline is a powerful method for characterizing complex glycans using tandem mass spectrometry (MS). As previously described, this activation method leads to rich fragmentation spectra with many structurally valuable cross-ring cleavages while maintaining labile modifications on the glycan structures. However, until now, the tandem MS event was too long to be compatible with liquid chromatography elution times. In this work, the duty cycle of the activation and detection of fragments was shortened, and the background signal on the spectra was drastically reduced. Both improvements allowed, for the first time, the successful coupling of a UHPLC system to XUV-activated tandem MS. The approach was used to characterize a complex mixture of oligo-porphyrans, which are a class of highly sulfated oligosaccharides, in a fully automated way. Due to an enhanced dynamic range and an increased sensitivity, some hypothetical structures of low abundance have been unequivocally confirmed in this study and others have been revised. Some previously undescribed species of oligo-porphyrans that exhibit lateral branching have been fully resolved. This work contributes to the scarce knowledge of the structure of porphyrans in red algae and pushes the current capacities of XUV-activation tandem MS by demonstrating the possibility of a direct coupling with UHPLC. This study will considerably broaden the applicability and practicality of this method in many fields of analytical biology. - Highlights: • For the first time, XUV photon activation tandem MS was coupled to UHPLC. • The approach was used to characterize a complex mixture of biomolecules. • The MSMS duty cycle was compatible with elution times of UHPLC without compromised. • Minor species were characterized with an enhanced sensitivity and dynamic range. • These results broaden the application of the technique in many field of

  5. Online coupling of high-resolution chromatography with extreme UV photon activation tandem mass spectrometry: Application to the structural investigation of complex glycans by dissociative photoionization

    Energy Technology Data Exchange (ETDEWEB)

    Ropartz, David, E-mail: David.Ropartz@nantes.inra.fr [INRA, UR1268 Biopolymers Interactions Assemblies F-44316 Nantes (France); Giuliani, Alexandre [Synchrotron SOLEIL, L' Orme des Merisiers, F-91190 Gif-sur-Yvette (France); UAR 1008 CEPIA, INRA, F-44316 Nantes (France); Fanuel, Mathieu [INRA, UR1268 Biopolymers Interactions Assemblies F-44316 Nantes (France); Hervé, Cécile; Czjzek, Mirjam [Sorbonne Universités, Université Pierre et Marie Curie, Paris VI, CNRS, Integrative Biology of Marine Models, UMR 8227, Station Biologique, Place George Teissier, F29688 Roscoff Cedex (France); Rogniaux, Hélène [INRA, UR1268 Biopolymers Interactions Assemblies F-44316 Nantes (France)

    2016-08-24

    The activation of ions by extreme-energy photons (XUV) produced by a synchrotron radiation beamline is a powerful method for characterizing complex glycans using tandem mass spectrometry (MS). As previously described, this activation method leads to rich fragmentation spectra with many structurally valuable cross-ring cleavages while maintaining labile modifications on the glycan structures. However, until now, the tandem MS event was too long to be compatible with liquid chromatography elution times. In this work, the duty cycle of the activation and detection of fragments was shortened, and the background signal on the spectra was drastically reduced. Both improvements allowed, for the first time, the successful coupling of a UHPLC system to XUV-activated tandem MS. The approach was used to characterize a complex mixture of oligo-porphyrans, which are a class of highly sulfated oligosaccharides, in a fully automated way. Due to an enhanced dynamic range and an increased sensitivity, some hypothetical structures of low abundance have been unequivocally confirmed in this study and others have been revised. Some previously undescribed species of oligo-porphyrans that exhibit lateral branching have been fully resolved. This work contributes to the scarce knowledge of the structure of porphyrans in red algae and pushes the current capacities of XUV-activation tandem MS by demonstrating the possibility of a direct coupling with UHPLC. This study will considerably broaden the applicability and practicality of this method in many fields of analytical biology. - Highlights: • For the first time, XUV photon activation tandem MS was coupled to UHPLC. • The approach was used to characterize a complex mixture of biomolecules. • The MSMS duty cycle was compatible with elution times of UHPLC without compromised. • Minor species were characterized with an enhanced sensitivity and dynamic range. • These results broaden the application of the technique in many field of

  6. Complex nature of SNP genotype effects on gene expression in primary human leucocytes

    Directory of Open Access Journals (Sweden)

    Dinesen Lotte C

    2009-01-01

    Full Text Available Abstract Background Genome wide association studies have been hugely successful in identifying disease risk variants, yet most variants do not lead to coding changes and how variants influence biological function is usually unknown. Methods We correlated gene expression and genetic variation in untouched primary leucocytes (n = 110 from individuals with celiac disease – a common condition with multiple risk variants identified. We compared our observations with an EBV-transformed HapMap B cell line dataset (n = 90, and performed a meta-analysis to increase power to detect non-tissue specific effects. Results In celiac peripheral blood, 2,315 SNP variants influenced gene expression at 765 different transcripts (cis expression quantitative trait loci, eQTLs. 135 of the detected SNP-probe effects (reflecting 51 unique probes were also detected in a HapMap B cell line published dataset, all with effects in the same allelic direction. Overall gene expression differences within the two datasets predominantly explain the limited overlap in observed cis-eQTLs. Celiac associated risk variants from two regions, containing genes IL18RAP and CCR3, showed significant cis genotype-expression correlations in the peripheral blood but not in the B cell line datasets. We identified 14 genes where a SNP affected the expression of different probes within the same gene, but in opposite allelic directions. By incorporating genetic variation in co-expression analyses, functional relationships between genes can be more significantly detected. Conclusion In conclusion, the complex nature of genotypic effects in human populations makes the use of a relevant tissue, large datasets, and analysis of different exons essential to enable the identification of the function for many genetic risk variants in common diseases.

  7. Mandelbrot's Extremism

    NARCIS (Netherlands)

    Beirlant, J.; Schoutens, W.; Segers, J.J.J.

    2004-01-01

    In the sixties Mandelbrot already showed that extreme price swings are more likely than some of us think or incorporate in our models.A modern toolbox for analyzing such rare events can be found in the field of extreme value theory.At the core of extreme value theory lies the modelling of maxima

  8. Tetra- and hexavalent uranium forms bidentate-mononuclear complexes with particulate organic matter in a naturally uranium-enriched peatland

    DEFF Research Database (Denmark)

    Mikutta, Christian; Langner, Peggy; Bargar, John R.

    2016-01-01

    Peatlands frequently serve as efficient biogeochemical traps for U. Mechanisms of U immobilization in these organic matter-dominated environments may encompass the precipitation of U-bearing mineral(oid)s and the complexation of U by a vast range of (in)organic surfaces. The objective of this work...... of bidentate-mononuclear U(IV/VI) complexes with carboxyl groups. We neither found evidence for U shells at ∼3.9 Å, indicative of mineral-associated U or multinuclear U(IV) species, nor for a substantial P/Fe coordination of U. Our data indicates that U(IV/VI) complexation by natural organic matter prevents...... the precipitation of U minerals as well as U complexation by Fe/Mn phases at our field site, and suggests that organically complexed U(IV) is formed via reduction of organic matter-bound U(VI)....

  9. The Natural Aging Effect on Hardenability in Al-Mg-Si: A Complex Interaction between Composition and Heat Treatment Parameters

    Directory of Open Access Journals (Sweden)

    Alex Poznak

    2018-05-01

    Full Text Available The technological relevance of Al-Mg-Si alloys has been rapidly growing over the last decade. Of particular interest to current and future applications is the problematic negative effect of prior natural aging on subsequent artificial age hardening. The influence of natural aging is dependent on both processing and compositional variables and has origins that are far from well-understood. This work examines the hardenability of 6000 series alloys under a wide range of conditions, paying particular attention to the natural aging effect. Experimental variables include alloy composition (Mg + Si, Mg/Si, cooling rate after solutionization, and duration of prior natural aging. Hardenability was evaluated with full hardness and conductivity aging curves for each condition, as well as select Transmission Electron Microscopy (TEM. Results are discussed based on the actions of naturally aged solute clusters during artificial aging. In particular, a complex interaction between vacancy concentration, cluster stability, and precipitation driving force is suggested.

  10. Determination of crystal structures by x-ray diffraction: applications to a lanthanide complex and a natural organic compound

    International Nuclear Information System (INIS)

    Miranda, J.M. de.

    1986-01-01

    The study fir determining crystal structures of the Ho (ReO sub(4)) sub(3) 4 TDTD 3 H sub(2) O complex and the natural organic compound C sub(14) H sub(16) O sub(6) by X-ray diffraction are presented. The experimental equipments are described in details. (M.C.K.)

  11. Humic substances in natural waters and their complexation with trace metals and radionuclides: a review

    International Nuclear Information System (INIS)

    Boggs, S. Jr.; Livermore, D.; Seitz, M.G.

    1985-07-01

    Dissolved humic substances (humic and fulvic acids) occur in surface waters and groundwaters in concentrations ranging from less than 1 mg(C)/L to more than 100 mg(C)/L. Humic substances are strong complexing agents for many trace metals in the environment and are also capable of forming stable soluble complexes or chelates with radionuclides. Concentrations of humic materials as low as 1 mg(C)/L can produce a detectable increase in the mobility of some actinide elements by forming soluble complexes that inhibit sorption of the radionuclides onto rock materials. The stability of trace metal- or radionuclide-organic complexes is commonly measured by an empirically determined conditional stability constant (K'), which is based on the ratio of complexed metal (radionuclide) in solution to the product concentration of uncomplexed metal and humic complexant. Larger values of stability constants indicate greater complex stability. The stability of radionuclide-organic complexes is affected both by concentration variables and envionmental factors. In general, complexing is favored by increased of radionuclide, increased pH, and decreased ionic strength. Actinide elements are generally most soluble in their higher oxidation states. Radionuclides can also form stable, insoluble complexes with humic materials that tend to reduce radionuclide mobility. These insoluble complexes may be radionuclide-humate colloids that subsequently precipitate from solution, or complexes of radionuclides and humic substances that sorb to clay minerals or other soil particulates strongly enough to immobilize the radionuclides. Colloid formation appears to be favored by increased radionuclide concentration and lowered pH; however, the conditions that favor formation of insoluble complexes that sorb to particulates are still poorly understood. 129 refs., 25 figs., 19 tabs

  12. Diagnosing the Nature of Land-Atmosphere Coupling During the 2006-7 Dry/Wet Extremes in the U. S. Southern Great Plains

    Science.gov (United States)

    Santanello, Joseph A.; Peters-Lidard, Christa D.; Kennedy, Aaron D.; Kumar, Sujay; Dong, Xiquan

    2011-01-01

    Land-atmosphere (L-A) interactions play a critical role in determining the diurnal evolution of land surface and planetary boundary layer (PBL) temperature and moisture states and fluxes. In turn, these interactions regulate the strength of the connection between surface moisture and precipitation in a coupled system. To address deficiencies in numerical weather prediction and climate models due to improper treatment of L-A interactions, recent studies have focused on development of diagnostics to quantify the strength and accuracy of the land-PBL coupling at the process-level. In this study, a diagnosis of the nature and impacts of local land-atmosphere coupling (LoCo) during dry and wet extreme conditions is presented using a combination of models and observations during the summers of2006-7 in the U.S. Southern Great Plains. Specifically, the Weather Research and Forecasting (WRF) model has been coupled to NASA's Land Information System (LIS), which provides a flexible and high resolution representation and initialization of land surface physics and states. A range of diagnostics exploring the links and feedbacks between soil moisture and precipitation are examined for the dry/wet regimes of this region, along with the behavior and accuracy of different land-PBL scheme couplings under these conditions. Results demonstrate how LoCo diagnostics can be applied to coupled model components in the context of their integrated impacts on the process-chain connecting the land surface to the PBL and support of hydrological anomalies.

  13. The Gaia-ESO Survey: Exploring the complex nature and origins of the Galactic bulge populations

    Science.gov (United States)

    Rojas-Arriagada, A.; Recio-Blanco, A.; de Laverny, P.; Mikolaitis, Š.; Matteucci, F.; Spitoni, E.; Schultheis, M.; Hayden, M.; Hill, V.; Zoccali, M.; Minniti, D.; Gonzalez, O. A.; Gilmore, G.; Randich, S.; Feltzing, S.; Alfaro, E. J.; Babusiaux, C.; Bensby, T.; Bragaglia, A.; Flaccomio, E.; Koposov, S. E.; Pancino, E.; Bayo, A.; Carraro, G.; Casey, A. R.; Costado, M. T.; Damiani, F.; Donati, P.; Franciosini, E.; Hourihane, A.; Jofré, P.; Lardo, C.; Lewis, J.; Lind, K.; Magrini, L.; Morbidelli, L.; Sacco, G. G.; Worley, C. C.; Zaggia, S.

    2017-05-01

    Context. As observational evidence steadily accumulates, the nature of the Galactic bulge has proven to be rather complex: the structural, kinematic, and chemical analyses often lead to contradictory conclusions. The nature of the metal-rich bulge - and especially of the metal-poor bulge - and their relation with other Galactic components, still need to be firmly defined on the basis of statistically significant high-quality data samples. Aims: We used the fourth internal data release of the Gaia-ESO survey to characterize the bulge metallicity distribution function (MDF), magnesium abundance, spatial distribution, and correlation of these properties with kinematics. Moreover, the homogeneous sampling of the different Galactic populations provided by the Gaia-ESO survey allowed us to perform a comparison between the bulge, thin disk, and thick disk sequences in the [Mg/Fe] vs. [Fe/H] plane in order to constrain the extent of their eventual chemical similarities. Methods: We obtained spectroscopic data for 2500 red clump stars in 11 bulge fields, sampling the area -10° ≤ l ≤ + 8° and -10° ≤ b ≤ -4° from the fourth internal data release of the Gaia-ESO survey. A sample of 6300 disk stars was also selected for comparison. Spectrophotometric distances computed via isochrone fitting allowed us to define a sample of stars likely located in the bulge region. Results: From a Gaussian mixture models (GMM) analysis, the bulge MDF is confirmed to be bimodal across the whole sampled area. The relative ratio between the two modes of the MDF changes as a function of b, with metal-poor stars dominating at high latitudes. The metal-rich stars exhibit bar-like kinematics and display a bimodality in their magnitude distribution, a feature which is tightly associated with the X-shape bulge. They overlap with the metal-rich end of the thin disk sequence in the [Mg/Fe] vs. [Fe/H] plane. On the other hand, metal-poor bulge stars have a more isotropic hot kinematics and do

  14. Effects of molecular composition of natural organic matter on ferric iron complexation at circumneutral pH.

    Science.gov (United States)

    Fujii, Manabu; Imaoka, Akira; Yoshimura, Chihiro; Waite, T D

    2014-04-15

    Thermodynamic and kinetic parameters for ferric iron (Fe[III]) complexation by well-characterized humic substances (HS) from various origins were determined by a competitive ligand method with 5-sulfosalicylic acid at circumneutral pH (6.0-8.0) and an ionic strength of ∼0.06 M. The measured Fe binding properties including conditional stability constants and complexation capacities ranged over more than 2 orders of magnitude, depending on the origin and the particular operationally defined fraction of HS examined. Statistical comparison of the complexation parameters to a range of chemical properties of the HS indicated a strong positive correlation between Fe(III) complexation capacity and aromatic carbon content in the HS at all pHs examined. In contrast, the complexation capacity was determined to be up to a few orders of magnitude smaller than the concentration of carboxylic and phenolic groups present. Therefore, specific functional groups including those resident in the proximity of aromatic structures within the HS are likely preferable for Fe(III) coordination under the conditions examined. Overall, our results suggest that the concentration of dissolved Fe(III) complexes in natural waters is substantially influenced by variation in HS characteristics in addition to other well-known factors such as HS concentration and nature and concentration of competing cations present.

  15. Neutron scattering with deuterium labeling reveals the nature of complexes formed by Ca{sup 2+}-binding proteins and their regulatory targets

    Energy Technology Data Exchange (ETDEWEB)

    Trewhella, J. [Los Alamos National Laboratory, NM (United States)

    1994-12-01

    Small-angle neutron scattering with deuterium labeling is extremely useful for studying the structures of complex biomolecular assemblies in solution. The different neutron scattering properties of their isotopes of hydrogen combines with the ability to uniformly label biomolecules with deuterium allow one to characterize the structures and relative dispositions of the individual components of an assembly using methods of {open_quotes}contrast variation.{close_quotes} We have applied these techniques to studies of the evolutionarily related dumbbell-shaped Ca{sup 2+}-binding proteins calmodulin and troponin C and their interactions with the target proteins whose activities they regulate. Ca{sup 2+} is one of the simplest of nature`s messengers used in the communication pathways between physiological stimulus and cellular response. The signaling mechanism generally involves Ca{sup 2+} binding to a protein and inducing a conformational change that transmits a signal to modify the activity of a specific target protein. Ca{sup 2+} is thus important in the regulation of a diverse array of intracellular responses, including neurotransmitter release, muscle contraction, the degradation of glycogen to glucose to generate energy, microtubule assembly, membrane phosphorylation, etc. It is the conformational language of the Ca{sup 2+} induced signal transduction that we have sought to understand because of its central importance to biochemical regulation and, hence, to healthy cellular function.

  16. Retention of habitat complexity minimizes disassembly of reef fish communities following disturbance: a large-scale natural experiment.

    Directory of Open Access Journals (Sweden)

    Michael J Emslie

    Full Text Available High biodiversity ecosystems are commonly associated with complex habitats. Coral reefs are highly diverse ecosystems, but are under increasing pressure from numerous stressors, many of which reduce live coral cover and habitat complexity with concomitant effects on other organisms such as reef fishes. While previous studies have highlighted the importance of habitat complexity in structuring reef fish communities, they employed gradient or meta-analyses which lacked a controlled experimental design over broad spatial scales to explicitly separate the influence of live coral cover from overall habitat complexity. Here a natural experiment using a long term (20 year, spatially extensive (∼ 115,000 kms(2 dataset from the Great Barrier Reef revealed the fundamental importance of overall habitat complexity for reef fishes. Reductions of both live coral cover and habitat complexity had substantial impacts on fish communities compared to relatively minor impacts after major reductions in coral cover but not habitat complexity. Where habitat complexity was substantially reduced, species abundances broadly declined and a far greater number of fish species were locally extirpated, including economically important fishes. This resulted in decreased species richness and a loss of diversity within functional groups. Our results suggest that the retention of habitat complexity following disturbances can ameliorate the impacts of coral declines on reef fishes, so preserving their capacity to perform important functional roles essential to reef resilience. These results add to a growing body of evidence about the importance of habitat complexity for reef fishes, and represent the first large-scale examination of this question on the Great Barrier Reef.

  17. Thermodynamics of inclusion complex formation of β-cyclodextrin with a variety of surfactants differing in the nature of headgroup

    International Nuclear Information System (INIS)

    Benkő, Mária; Király, Zoltán

    2012-01-01

    Highlights: ► Inclusion complexation of β-cyclodextrins with various surfactants. ► Thermodynamic parameters determined by titration microcalorimetry. ► Stoichiometry of complexation is 1:1. ► The binding constant decreases linearly with increasing temperature. ► Enthalpy–entropy compensation is independent of the nature of the headgroup. - Abstract: The inclusion complexation of β-cyclodextrin with various surfactants, possessing the same alkyl chain length but differing in the hydrophilic headgroup, was investigated by isothermal titration microcalorimetry. Sodium dodecyl sulfate, sodium dodecyl sulfonate, dodecyltrimethylammonium bromide and dodecyl(dimethyl)amine oxide were investigated. The major aim of this study was to elucidate the effects of temperature and the nature of the headgroup on the complex formation. Thermometric titrations were effected between the temperatures (288 and 348) K. The results provided the stoichiometry, the equilibrium constant and the reaction enthalpy of complexation. Changes in Gibbs energy, entropy and van’t Hoff enthalpy were additionally calculated.

  18. Molecular Basis of Natural Killer Cell Tumor Target Recognition: The NKr/MHC Class I Complex

    National Research Council Canada - National Science Library

    Hasemann, Charles

    1999-01-01

    .... We have pursued this via the heterologous expression of wild type and mutant NK receptors for the purpose of the determination of the atomic structure of an NK receptor/ class I MHC complex via X-ray crystallography...

  19. Nature of complex time eigenvalues of the one speed transport equation in a homogeneous sphere

    International Nuclear Information System (INIS)

    Dahl, E.B.; Sahni, D.C.

    1990-01-01

    The complex time eigenvalues of the transport equation have been studied for one speed neutrons, scattered isotropically in a homogeneous sphere with vacuum boundary conditions. It is shown that the complex decay constants vary continuously with the radius of the sphere. Our earlier conjecture (Dahl and Sahni (1983-84)) regarding disjoint arcs is thus shown to be true. We also indicate that complex decay constants exist even for large assemblies, though with rapid oscillations in the corresponding eigenvectors. These modes cannot be predicted by the diffusion equation as this behaviour of the eigenvectors contradicts the assumption of 'slowly varying flux' needed to derive the diffusion approximation from the transport equation. For an infinite system, the existence of complex modes is related to the solution of a homogeneous equation. (author)

  20. Lanthanide and actinide inorganic complexes in natural waters. TRLFS and ESI-MS studies

    Energy Technology Data Exchange (ETDEWEB)

    Vercouter, T.; Amekraz, B.; Moulin, C.; Vitorge, P

    2004-07-01

    Aqueous complexes of M(III) f-element ions with the inorganic ligands CO{sub 3}{sup 2-} and SO{sub 4}{sup 2-} have been investigated using the highly-sensitive speciation techniques TRLFS and ESI-MS. The Eu(CO{sub 3}){sub i}{sup 3-2i} (i=1-3) species have been characterized by TRLFS, and the stoichiometry of the limiting complex Eu(CO{sub 3}){sub 3}{sup 3-} have been confirmed by solubility measurements of NaEu(CO{sub 3}){sub 2}(s) at high ionic strength. Temperature effect on Cm(III) carbonate complexes is evidenced by the TRLFS technique. Investigation on sulphate complexation has been done at various ionic strengths by TRLFS on Eu(III) and by ESI-MS on La(III). New thermodynamic data are obtained by both techniques, which are consistent with literature data. (authors)

  1. Proactive systems for early warning of potential impacts of natural disasters on food safety: Climate-change-induced extreme events as case in point

    NARCIS (Netherlands)

    Marvin, H.J.P.; Kleter, G.A.; Fels-Klerx, van der H.J.; Noordam, M.Y.; Franz, E.; Willems, D.J.M.; Boxall, A.

    2013-01-01

    According to a recent report of the Intergovernmental Panel on Climate Change, the frequency of certain climate extremes is expected to increase under the influence of climate change. This review presents potential direct and indirect effects of such extremes as well as other severe weather and

  2. Hypoxic survival strategies in two fishes: extreme anoxia tolerance in the North European crucian carp and natural hypoxic preconditioning in a coral-reef shark.

    Science.gov (United States)

    Nilsson, Göran E; Renshaw, Gillian M C

    2004-08-01

    Especially in aquatic habitats, hypoxia can be an important evolutionary driving force resulting in both convergent and divergent physiological strategies for hypoxic survival. Examining adaptations to anoxic/hypoxic survival in hypoxia-tolerant animals may offer fresh ideas for the treatment of hypoxia-related diseases. Here, we summarise our present knowledge of two fishes that have evolved to survive hypoxia under very different circumstances. The crucian carp (Carassius carassius) is of particular interest because of its extreme anoxia tolerance. During the long North European winter, it survives for months in completely oxygen-deprived freshwater habitats. The crucian carp also tolerates a few days of anoxia at room temperature and, unlike anoxia-tolerant freshwater turtles, it is still physically active in anoxia. Moreover, the crucian carp does not appear to reduce neuronal ion permeability during anoxia and may primarily rely on more subtle neuromodulatory mechanisms for anoxic metabolic depression. The epaulette shark (Hemiscyllium ocellatum) is a tropical marine vertebrate. It lives on shallow reef platforms that repeatedly become cut off from the ocean during periods of low tides. During nocturnal low tides, the water [O(2)] can fall by 80% due to respiration of the coral and associated organisms. Since the tides become lower and lower over a period of a few days, the hypoxic exposure during subsequent low tides will become progressively longer and more severe. Thus, this shark is under a natural hypoxic preconditioning regimen. Interestingly, hypoxic preconditioning lowers its metabolic rate and its critical P(O(2)). Moreover, repeated anoxia appears to stimulate metabolic depression in an adenosine-dependent way.

  3. Diagnosing the Nature of Land-Atmosphere Coupling: A Case Study of Dry/Wet Extremes in the U.S. Southern Great Plains

    Science.gov (United States)

    Santanello, Joseph A., Jr.; Peters-Lidard, Christa D.; Kennedy, Aaron; Kumar, Sujay V.

    2012-01-01

    Land-atmosphere (L-A) interactions play a critical role in determining the diurnal evolution of land surface and planetary boundary layer (PBL) temperature and moisture states and fluxes. In turn, these interactions regulate the strength of the connection between surface moisture and precipitation in a coupled system. To address model deficiencies, recent studies have focused on development of diagnostics to quantify the strength and accuracy of the land-PBL coupling at the process level. In this paper, a diagnosis of the nature and impacts of local land-atmosphere coupling (LoCo) during dry and wet extreme conditions is presented using a combination of models and observations during the summers of 2006 and 2007 in the U.S. southern Great Plains. A range of diagnostics exploring the links and feedbacks between soil moisture and precipitation is applied to the dry/wet regimes exhibited in this region, and in the process, a thorough evaluation of nine different land-PBL scheme couplings is conducted under the umbrella of a high-resolution regional modeling test bed. Results show that the sign and magnitude of errors in land surface energy balance components are sensitive to the choice of land surface model, regime type, and running mode. In addition, LoCo diagnostics show that the sensitivity of L-A coupling is stronger toward the land during dry conditions, while the PBL scheme coupling becomes more important during the wet regime. Results also demonstrate how LoCo diagnostics can be applied to any modeling system (e.g., reanalysis products) in the context of their integrated impacts on the process chain connecting the land surface to the PBL and in support of hydrological anomalies.

  4. Nature and provenance of the Beishan Complex, southernmost Central Asian Orogenic Belt

    Science.gov (United States)

    Zheng, Rongguo; Li, Jinyi; Xiao, Wenjiao; Zhang, Jin

    2018-03-01

    The ages and origins of metasedimentary rocks, which were previously mapped as Precambrian, are critical in rebuilding the orogenic process and better understanding the Phanerozoic continental growth in the Central Asian Orogenic Belt (CAOB). The Beishan Complex was widely distributed in the southern Beishan Orogenic Collage, southernmost CAOB, and their ages and tectonic affinities are still in controversy. The Beishan Complex was previously proposed as fragments drifted from the Tarim Craton, Neoproterozoic Block or Phanerozoic accretionary complex. In this study, we employ detrital zircon age spectra to constrain ages and provenances of metasedimentary sequences of the Beishan Complex in the Chuanshanxun area. The metasedimentary rocks here are dominated by zircons with Paleoproterozoic-Mesoproterozoic age ( 1160-2070 Ma), and yield two peak ages at 1454 and 1760 Ma. One sample yielded a middle Permian peak age (269 Ma), which suggests that the metasedimentary sequences were deposited in the late Paleozoic. The granitoid and dioritic dykes, intruding into the metasedimentary sequences, exhibit zircon U-Pb ages of 268 and 261 Ma, respectively, which constrain the minimum deposit age of the metasedimentary sequences. Zircon U-Pb ages of amphibolite (274 and 216 Ma) indicate that they might be affected by multi-stage metamorphic events. The Beishan Complex was not a fragment drifted from the Tarim Block or Dunhuang Block, and none of cratons or blocks surrounding Beishan Orogenic Collage was the sole material source of the Beishan Complex due to obviously different age spectra. Instead, 1.4 Ga marginal accretionary zones of the Columbia supercontinent might have existed in the southern CAOB, and may provide the main source materials for the sedimentary sequences in the Beishan Complex.

  5. The relative contribution of natural zinc complexing agents and ZnSO4 to growth and zinc nutrition of maize

    International Nuclear Information System (INIS)

    Kumar, M.; Prasad, B.

    1989-01-01

    Relative evaluation of different natural zinc-complexes indicated that application of Zn-FA 2 (PM), Zn-FA 3 (Comp), Zn-FA 1 (BGS), Zn-FA 5 (PR), Zn-FA 4 (SS) and ZnSO 4 significantly enhanced the drymatter yield and zinc uptake by maize. The natural zinc-complexes in particular increased, to a greater extent, the uptake of both native and applied sources than that observed with ZnSO 4 as zinc carrier. Significant positive relationship between self-diffusion coefficient of Zn and drymatter yield and uptake of zinc by maize suggested that diffusion is responsible for the supply of zinc from ambient soil matrix to plant roots. (author). 12 refs., 5 tabs

  6. Metabolic signatures of extreme longevity in northern Italian centenarians reveal a complex remodeling of lipids, amino acids, and gut microbiota metabolism.

    Directory of Open Access Journals (Sweden)

    Sebastiano Collino

    Full Text Available The aging phenotype in humans has been thoroughly studied but a detailed metabolic profiling capable of shading light on the underpinning biological processes of longevity is still missing. Here using a combined metabonomics approach compromising holistic (1H-NMR profiling and targeted MS approaches, we report for the first time the metabolic phenotype of longevity in a well characterized human aging cohort compromising mostly female centenarians, elderly, and young individuals. With increasing age, targeted MS profiling of blood serum displayed a marked decrease in tryptophan concentration, while an unique alteration of specific glycerophospholipids and sphingolipids are seen in the longevity phenotype. We hypothesized that the overall lipidome changes specific to longevity putatively reflect centenarians' unique capacity to adapt/respond to the accumulating oxidative and chronic inflammatory conditions characteristic of their extreme aging phenotype. Our data in centenarians support promotion of cellular detoxification mechanisms through specific modulation of the arachidonic acid metabolic cascade as we underpinned increased concentration of 8,9-EpETrE, suggesting enhanced cytochrome P450 (CYP enzyme activity. Such effective mechanism might result in the activation of an anti-oxidative response, as displayed by decreased circulating levels of 9-HODE and 9-oxoODE, markers of lipid peroxidation and oxidative products of linoleic acid. Lastly, we also revealed that the longevity process deeply affects the structure and composition of the human gut microbiota as shown by the increased extrection of phenylacetylglutamine (PAG and p-cresol sulfate (PCS in urine of centenarians. Together, our novel approach in this representative Italian longevity cohort support the hypothesis that a complex remodeling of lipid, amino acid metabolism, and of gut microbiota functionality are key regulatory processes marking exceptional longevity in humans.

  7. Fort Collins Science Center Ecosystem Dynamics branch--interdisciplinary research for addressing complex natural resource issues across landscapes and time

    Science.gov (United States)

    Bowen, Zachary H.; Melcher, Cynthia P.; Wilson, Juliette T.

    2013-01-01

    The Ecosystem Dynamics Branch of the Fort Collins Science Center offers an interdisciplinary team of talented and creative scientists with expertise in biology, botany, ecology, geology, biogeochemistry, physical sciences, geographic information systems, and remote-sensing, for tackling complex questions about natural resources. As demand for natural resources increases, the issues facing natural resource managers, planners, policy makers, industry, and private landowners are increasing in spatial and temporal scope, often involving entire regions, multiple jurisdictions, and long timeframes. Needs for addressing these issues include (1) a better understanding of biotic and abiotic ecosystem components and their complex interactions; (2) the ability to easily monitor, assess, and visualize the spatially complex movements of animals, plants, water, and elements across highly variable landscapes; and (3) the techniques for accurately predicting both immediate and long-term responses of system components to natural and human-caused change. The overall objectives of our research are to provide the knowledge, tools, and techniques needed by the U.S. Department of the Interior, state agencies, and other stakeholders in their endeavors to meet the demand for natural resources while conserving biodiversity and ecosystem services. Ecosystem Dynamics scientists use field and laboratory research, data assimilation, and ecological modeling to understand ecosystem patterns, trends, and mechanistic processes. This information is used to predict the outcomes of changes imposed on species, habitats, landscapes, and climate across spatiotemporal scales. The products we develop include conceptual models to illustrate system structure and processes; regional baseline and integrated assessments; predictive spatial and mathematical models; literature syntheses; and frameworks or protocols for improved ecosystem monitoring, adaptive management, and program evaluation. The descriptions

  8. An Investigation into the Factors Affecting the Design of Nature-Compatible Recreational-Residential Complexes- Instance Analysis

    Directory of Open Access Journals (Sweden)

    Seyyedeh Fatemeh Safavi Mirmahalleh

    2017-02-01

    Full Text Available Explaining tourism concepts, standards of recreational-residential complexes and the methods for accurate treating with nature, this paper tries to study the suitable instances of recreational-residential complexes and to adopt their positive aspects as a design strategy. SWOT matrix was built based on the weaknesses and strengths of the project site and design principles were derived by observing the extracted influential factors. Considering land topography, for example, different areas of buildings were shifted and combined with the nature. - Residential and public zones gained a nice view towards the nature by keeping their orientation and extending them in east-west direction - Service section connected more appropriately with residential and public areas - Sections which do not need extra light such as W.Cs, storages and installation rooms, were considered in a side of the building which was adjacent to soil - In residential section, rhythm was implemented in ceilings and windows - Golden values and proportions were used to design the plane and façade of the complex

  9. Complex Networks Dynamics Based on Events-Phase Synchronization and Intensity Correlation Applied to The Anomaly Patterns and Extremes in The Tropical African Climate System

    Science.gov (United States)

    Oluoch, K.; Marwan, N.; Trauth, M.; Loew, A.; Kurths, J.

    2012-04-01

    The African continent lie almost entirely within the tropics and as such its (tropical) climate systems are predominantly governed by the heterogeneous, spatial and temporal variability of the Hadley and Walker circulations. The variabilities in these meridional and zonal circulations lead to intensification or suppression of the intensities, durations and frequencies of the Inter-tropical Convergence Zone (ICTZ) migration, trade winds and subtropical high-pressure regions and the continental monsoons. The above features play a central role in determining the African rainfall spatial and temporal variability patterns. The current understanding of these climate features and their influence on the rainfall patterns is not sufficiently understood. Like many real-world systems, atmospheric-oceanic processes exhibit non-linear properties that can be better explored using non-linear (NL) methods of time-series analysis. Over the recent years, the complex network approach has evolved as a powerful new player in understanding spatio-temporal dynamics and evolution of complex systems. Together with NL techniques, it is continuing to find new applications in many areas of science and technology including climate research. We would like to use these two powerful methods to understand the spatial structure and dynamics of African rainfall anomaly patterns and extremes. The method of event synchronization (ES) developed by Quiroga et al., 2002 and first applied to climate networks by Malik et al., 2011 looks at correlations with a dynamic time lag and as such, it is a more intuitive way to correlate a complex and heterogeneous system like climate networks than a fixed time delay most commonly used. On the other hand, the short comings of ES is its lack of vigorous test statistics for the significance level of the correlations, and the fact that only the events' time indices are synchronized while all information about how the relative intensities propagate within network

  10. Entropy: A Unifying Path for Understanding Complexity in Natural, Artificial and Social Systems

    Science.gov (United States)

    2011-07-01

    details can be seen. Figure 24 – Rank frequency functions of plays ( Shakespeare ) and books (Dickens) fitted by the generalizations of the...0-387-75888-6]. [4] Tsallis, C. (2009b). Introduction to Nonextensive Statistical Mechanics - Approaching a Complex World. (Springer, New York

  11. Improved natural rubber composites reinforced with a complex filler network of biobased nanoparticles and ionomer

    Science.gov (United States)

    Biobased rubber composites are renewable and sustainable. Significant improvement in modulus of rubber composite reinforced with hydrophilic filler was achieved with the inclusion of ionomers. Soy particles aided with ionomer, carboxylated styrene-butadiene (CSB), formed a strong complex filler netw...

  12. Complexity of Naturally Produced Polybrominated Diphenyl Ethers Revealed via Mass Spectrometry

    Science.gov (United States)

    Agarwal, Vinayak; Li, Jie; Rahman, Imran; Borgen, Miles; Aluwihare, Lihini I.; Biggs, Jason S.; Paul, Valerie J.; Moore, Bradley S.

    2015-01-01

    Polybrominated diphenyl ethers (PBDEs) are persistent and bioaccumulative anthropogenic and natural chemicals that are broadly distributed in the marine environment. PBDEs are potentially toxic due to inhibition of various mammalian signaling pathways and enzymatic reactions. PBDE isoforms vary in toxicity in accordance with structural differences, primarily in the number and pattern of hydroxyl moieties afforded upon a conserved core structure. Over four decades of isolation and discovery-based efforts have established an impressive repertoire of natural PBDEs. Based on our recent reports describing the bacterial biosyntheses of PBDEs, we predicted the presence of additional classes of PBDEs to those previously identified from marine sources. Using mass spectrometry and NMR spectroscopy, we now establish the existence of new structural classes of PBDEs in marine sponges. Our findings expand the chemical space explored by naturally produced PBDEs, which may inform future environmental toxicology studies. Furthermore, we provide evidence for iodinated PBDEs and direct attention toward the contribution of promiscuous halogenating enzymes in further expanding the diversity of these polyhalogenated marine natural products. PMID:25559102

  13. Selection for long and short sleep duration in Drosophila melanogaster reveals the complex genetic network underlying natural variation in sleep.

    Science.gov (United States)

    Harbison, Susan T; Serrano Negron, Yazmin L; Hansen, Nancy F; Lobell, Amanda S

    2017-12-01

    Why do some individuals need more sleep than others? Forward mutagenesis screens in flies using engineered mutations have established a clear genetic component to sleep duration, revealing mutants that convey very long or short sleep. Whether such extreme long or short sleep could exist in natural populations was unknown. We applied artificial selection for high and low night sleep duration to an outbred population of Drosophila melanogaster for 13 generations. At the end of the selection procedure, night sleep duration diverged by 9.97 hours in the long and short sleeper populations, and 24-hour sleep was reduced to 3.3 hours in the short sleepers. Neither long nor short sleeper lifespan differed appreciably from controls, suggesting little physiological consequences to being an extreme long or short sleeper. Whole genome sequence data from seven generations of selection revealed several hundred thousand changes in allele frequencies at polymorphic loci across the genome. Combining the data from long and short sleeper populations across generations in a logistic regression implicated 126 polymorphisms in 80 candidate genes, and we confirmed three of these genes and a larger genomic region with mutant and chromosomal deficiency tests, respectively. Many of these genes could be connected in a single network based on previously known physical and genetic interactions. Candidate genes have known roles in several classic, highly conserved developmental and signaling pathways-EGFR, Wnt, Hippo, and MAPK. The involvement of highly pleiotropic pathway genes suggests that sleep duration in natural populations can be influenced by a wide variety of biological processes, which may be why the purpose of sleep has been so elusive.

  14. Selection for long and short sleep duration in Drosophila melanogaster reveals the complex genetic network underlying natural variation in sleep.

    Directory of Open Access Journals (Sweden)

    Susan T Harbison

    2017-12-01

    Full Text Available Why do some individuals need more sleep than others? Forward mutagenesis screens in flies using engineered mutations have established a clear genetic component to sleep duration, revealing mutants that convey very long or short sleep. Whether such extreme long or short sleep could exist in natural populations was unknown. We applied artificial selection for high and low night sleep duration to an outbred population of Drosophila melanogaster for 13 generations. At the end of the selection procedure, night sleep duration diverged by 9.97 hours in the long and short sleeper populations, and 24-hour sleep was reduced to 3.3 hours in the short sleepers. Neither long nor short sleeper lifespan differed appreciably from controls, suggesting little physiological consequences to being an extreme long or short sleeper. Whole genome sequence data from seven generations of selection revealed several hundred thousand changes in allele frequencies at polymorphic loci across the genome. Combining the data from long and short sleeper populations across generations in a logistic regression implicated 126 polymorphisms in 80 candidate genes, and we confirmed three of these genes and a larger genomic region with mutant and chromosomal deficiency tests, respectively. Many of these genes could be connected in a single network based on previously known physical and genetic interactions. Candidate genes have known roles in several classic, highly conserved developmental and signaling pathways-EGFR, Wnt, Hippo, and MAPK. The involvement of highly pleiotropic pathway genes suggests that sleep duration in natural populations can be influenced by a wide variety of biological processes, which may be why the purpose of sleep has been so elusive.

  15. Extreme cosmos

    CERN Document Server

    Gaensler, Bryan

    2011-01-01

    The universe is all about extremes. Space has a temperature 270°C below freezing. Stars die in catastrophic supernova explosions a billion times brighter than the Sun. A black hole can generate 10 million trillion volts of electricity. And hypergiants are stars 2 billion kilometres across, larger than the orbit of Jupiter. Extreme Cosmos provides a stunning new view of the way the Universe works, seen through the lens of extremes: the fastest, hottest, heaviest, brightest, oldest, densest and even the loudest. This is an astronomy book that not only offers amazing facts and figures but also re

  16. Correlation analysis of extremely low-frequency variations of the natural electromagnetic Earth field and the problem of detecting periodical gravitational radiation

    International Nuclear Information System (INIS)

    Balakin, A.B.; Murzakhanov, Z.G.; Grunskaya, L.V.

    1994-01-01

    A proposal on the experimental detection of extremely low-frequency variations of the electromagnetic Earth field at the gravitational-wave frequency and method for correlation processing results of the experiments are described. 14 refs

  17. Transportation System Vulnerability and Resilience to Extreme Weather Events and Other Natural Hazards : Final Results of Vulnerability Assessment of National Highway System for All KYTC Districts

    Science.gov (United States)

    2018-05-01

    Recent federal legislation and the Federal Highway Administration (FHWA) have directed state transportation agencies to identify potential vulnerabilities associated with extreme weather events and climate change, develop a risk-based asset managemen...

  18. Radar observations of a tornado-spawning storm complex in Southeast Brazil and Meso-Eta forecasts of this extreme event

    Science.gov (United States)

    Held, Gerhard; Gomes, Jorge Luis; Gomes, Ana Maria

    2014-05-01

    During the early afternoon of 22 September 2013, severe storms, accompanied by large hail, damaging winds, heavy precipitation and intense lightning activity, devastated a region in the southeast State of São Paulo. Several extremely intense storm cells moved at up to 80 km/h east-southeastwards, ahead of a strong cold front approaching through Paraná, which created extremely unstable conditions that led to deep convection and overshooting towers up to 18 km. At least one of theses cells spawned a tornado when it reached the town of Taquarituba. The tornado traversed the town from south-southwest to north-northeast and was responsible for 63 people injured and two fatalities. Based on the damage reported, it was at least an F3 according to the Fujita scale. The objective of the present study is to characterize this severe thunderstorm event, using different types of data, and to evaluate the forecasts provided by the Meso-Eta model centered over Bauru. The pre-frontal and frontal convective cells were tracked throughout their life-time by IPMet's Doppler radars, which cover the western and central regions of the State São Paulo, as well as northern Paraná State. Radar volume scans, generated every 7,5 min, were processed with the TITAN (Thunderstorm Identification, Tracking, Analysis and Nowcasting) Software, yielding the following preliminary results: as the storm complex traversed the Paranapanema River, which forms the border between the two states, the cells intensified drastically and shortly before reaching the town of Taquarituba, that particular cell displayed extremely strong radial shear just above the cloud base (about -20 to +35 m/s), which led to the formation of a deep meso-cyclone, from which the tornado spawned and touched down at around 14:30 LT (LT=UT-3h). Cell properties calculated by TITAN showed a drastic increase of VIL (Vertically Integrated Liquid water content) from 13:52 LT (7,9 kg/m2) to a maximum of 61,8 kg/m2 at 14:15 LT. From 14

  19. Neptunium(V) complexation by natural pyoverdins and related model compounds

    Energy Technology Data Exchange (ETDEWEB)

    Moll, H.; Glorius, M.; Bernhard, G. [Forschungszentrum Dresden-Rossendorf e.V., Inst. of Radiochemistry (Germany); Johnsson, A. [Goeteborg Univ., Microbiology, Dept. of Cell and Molecular Biology (Sweden); Univ. of Copenhagen, Dept. of Chemistry (Denmark); Schaefer, M.; Budzikiewicz, H. [Univ. zu Koeln, Inst. fuer Organische Chemie (Germany); Pedersen, K. [Goeteborg Univ., Microbiology, Dept. of Cell and Molecular Biology (Sweden)

    2010-07-01

    Ubiquitous fluorescent Pseudomonas species secrete bacterial pyoverdin-type siderophores. These bioligands have great potential to bind and transport actinides in the environment due to their hydroxamate and catechol functionalities. We investigated the unknown interaction of the neptunyl cation (NpO{sub 2}{sup +}) with pyoverdins (PYO) released by Pseudomonas fluorescens (CCUG 32456) cells and with simple hydroxamate (salicylhydroxamic acid: SHA and benzohydroxamic acid: BHA) and catechol (2,3-dihydroxynaphthalene: NAP) ligands using near-infrared (NIR) absorption spectroscopy over a wide pH range. NpO{sub 2}{sup +}-bioligand species of the M{sub x}L{sub y}H{sub z} type were identified from the spectrophotometric titrations in all four systems. The 1:1:2, 1:1:1, and 1:1:0 complexes were determined with the pyoverdins. In addition to 1:1 species, SHA, BHA, and NAP also form 1:2:0 species with NpO{sub 2}{sup +}. The stability constants of these neptunyl(V)-bioligand complexes and their individual spectroscopic properties are reported. Our findings indicate that NpO{sub 2}{sup +} has a stronger affinity to the catechol functionality of the pyoverdin molecule. The identified NpO{sub 2}{sup +}-PYO species belong to the strongest NpO{sub 2}{sup +} complexes with organic material reported so far. (orig.)

  20. Fuzzy approximate entropy analysis of chaotic and natural complex systems: detecting muscle fatigue using electromyography signals.

    Science.gov (United States)

    Xie, Hong-Bo; Guo, Jing-Yi; Zheng, Yong-Ping

    2010-04-01

    In the present contribution, a complexity measure is proposed to assess surface electromyography (EMG) in the study of muscle fatigue during sustained, isometric muscle contractions. Approximate entropy (ApEn) is believed to provide quantitative information about the complexity of experimental data that is often corrupted with noise, short data length, and in many cases, has inherent dynamics that exhibit both deterministic and stochastic behaviors. We developed an improved ApEn measure, i.e., fuzzy approximate entropy (fApEn), which utilizes the fuzzy membership function to define the vectors' similarity. Tests were conducted on independent, identically distributed (i.i.d.) Gaussian and uniform noises, a chirp signal, MIX processes, Rossler equation, and Henon map. Compared with the standard ApEn, the fApEn showed better monotonicity, relative consistency, and more robustness to noise when characterizing signals with different complexities. Performance analysis on experimental EMG signals demonstrated that the fApEn significantly decreased during the development of muscle fatigue, which is a similar trend to that of the mean frequency (MNF) of the EMG signal, while the standard ApEn failed to detect this change. Moreover, fApEn of EMG demonstrated a better robustness to the length of the analysis window in comparison with the MNF of EMG. The results suggest that the fApEn of an EMG signal may potentially become a new reliable method for muscle fatigue assessment and be applicable to other short noisy physiological signal analysis.

  1. BT-Nurse: computer generation of natural language shift summaries from complex heterogeneous medical data.

    Science.gov (United States)

    Hunter, James; Freer, Yvonne; Gatt, Albert; Reiter, Ehud; Sripada, Somayajulu; Sykes, Cindy; Westwater, Dave

    2011-01-01

    The BT-Nurse system uses data-to-text technology to automatically generate a natural language nursing shift summary in a neonatal intensive care unit (NICU). The summary is solely based on data held in an electronic patient record system, no additional data-entry is required. BT-Nurse was tested for two months in the Royal Infirmary of Edinburgh NICU. Nurses were asked to rate the understandability, accuracy, and helpfulness of the computer-generated summaries; they were also asked for free-text comments about the summaries. The nurses found the majority of the summaries to be understandable, accurate, and helpful (pgenerated summaries. In conclusion, natural language NICU shift summaries can be automatically generated from an electronic patient record, but our proof-of-concept software needs considerable additional development work before it can be deployed.

  2. Novel spin transition between S = 5/2 and S = 3/2 in highly saddled iron(III) porphyrin complexes at extremely low temperatures.

    Science.gov (United States)

    Ohgo, Yoshiki; Chiba, Yuya; Hashizume, Daisuke; Uekusa, Hidehiro; Ozeki, Tomoji; Nakamura, Mikio

    2006-05-14

    A novel spin transition between S = 5/2 and S = 3/2 has been observed for the first time in five-coordinate, highly saddled iron(III) porphyrinates by EPR and SQUID measurements at extremely low temperatures.

  3. A Naturally Occurring Antioxidant Complex from Unripe Grapes: The Case of Sangiovese (v. Vitis vinifera)

    OpenAIRE

    Giovanna Fia; Claudio Gori; Ginevra Bucalossi; Francesca Borghini; Bruno Zanoni

    2018-01-01

    The wine industry is well known for its production of a large amount of wastes and by-products. Among them, unripe grapes from thinning operations are an undervalued by-product. Grapes are an interesting source of natural antioxidants such as flavonoids, non-flavonoids and stilbenes. A potential strategy to exploit unripe grapes was investigated in this study. Juice from unripe grapes, v. Sangiovese, was obtained by an innovative technique of solid-liquid extraction without the use of solvent...

  4. Physics, nature and society a guide to order and complexity in our world

    CERN Document Server

    Marro, Joaquín

    2014-01-01

    This wide-ranging and accessible book serves as a fascinating guide to the strategies and concepts that help us understand the boundaries between physics, on the one hand, and sociology, economics, and biology on the other. From cooperation and criticality to flock dynamics and fractals, the author addresses many of the topics belonging to the broad theme of complexity. He chooses excellent examples (requiring no prior mathematical knowledge) to illuminate these ideas and their implications. The lively style and clear description of the relevant models will appeal both to novices and those with an existing knowledge of the field.

  5. natural

    Directory of Open Access Journals (Sweden)

    Elías Gómez Macías

    2006-01-01

    Full Text Available Partiendo de óxido de magnesio comercial se preparó una suspensión acuosa, la cual se secó y calcinó para conferirle estabilidad térmica. El material, tanto fresco como usado, se caracterizó mediante DRX, área superficial BET y SEM-EPMA. El catalizador mostró una matriz de MgO tipo periclasa con CaO en la superficie. Las pruebas de actividad catalítica se efectuaron en lecho fijo empacado con partículas obtenidas mediante prensado, trituración y clasificación del material. El flujo de reactivos consistió en mezclas gas natural-aire por debajo del límite inferior de inflamabilidad. Para diferentes flujos y temperaturas de entrada de la mezcla reactiva, se midieron las concentraciones de CH4, CO2 y CO en los gases de combustión con un analizador de gases tipo infrarrojo no dispersivo (NDIR. Para alcanzar conversión total de metano se requirió aumentar la temperatura de entrada al lecho a medida que se incrementó el flujo de gases reaccionantes. Los resultados obtenidos permiten desarrollar un sistema de combustión catalítica de bajo costo con un material térmicamente estable, que promueva la alta eficiencia en la combustión de gas natural y elimine los problemas de estabilidad, seguridad y de impacto ambiental negativo inherentes a los procesos de combustión térmica convencional.

  6. Natural disease course and genotype-phenotype correlations in Complex I deficiency caused by nuclear gene defects: what we learned from 130 cases

    NARCIS (Netherlands)

    Koene, S.; Rodenburg, R.J.; van der Knaap, M.S.; Willemsen, M.A.A.P.; Sperl, W.; Laugel, V.; Ostergaard, E.; Tarnopolsky, M.; Martin, M.A.; Nesbitt, V.; Fletcher, J.; Edvardson, S.; Procaccio, V.; Slama, A.; van den Heuvel, L.P.W.J.; Smeitink, J.A.M.

    2012-01-01

    Mitochondrial complex I is the largest multi-protein enzyme complex of the oxidative phosphorylation system. Seven subunits of this complex are encoded by the mitochondrial and the remainder by the nuclear genome. We review the natural disease course and signs and symptoms of 130 patients (four new

  7. Natural disease course and genotype-phenotype correlations in Complex I deficiency caused by nuclear gene defects: what we learned from 130 cases.

    NARCIS (Netherlands)

    Koene, S.; Rodenburg, R.J.T.; Knaap, M.S. van der; Willemsen, M.A.A.P.; Sperl, W.; Laugel, V.; Ostergaard, E.; Tarnopolsky, M.; Martin, M.A.; Nesbitt, V.; Fletcher, J.; Edvardson, S.; Procaccio, V.; Slama, A.; Heuvel, L.P.W.J. van den; Smeitink, J.A.M.

    2012-01-01

    Mitochondrial complex I is the largest multi-protein enzyme complex of the oxidative phosphorylation system. Seven subunits of this complex are encoded by the mitochondrial and the remainder by the nuclear genome. We review the natural disease course and signs and symptoms of 130 patients (four new

  8. Interaction of plutonium with complexing substances in soils and natural waters

    International Nuclear Information System (INIS)

    Bondietti, E.A.; Reynolds, S.A.; Shanks, M.H.

    1976-01-01

    The reactions of Pu with selected organic substances found in the environment have been studied to evaluate the valence and metalcomplex behaviour of Pu. Hexavalent Pu (and by inference pentavalent Pu) was unstable in the presence of fulvic acid, polygalacturonic acid, and alginic acid. Citrate-Pu(VI) complexes, however, were relatively more stable. Plutonium (IV) was the most stable valence upon interaction with these organics. Further reduction of Pu(IV) to Pu(III) occurred by fulvic and humic acids. The reduction, under aerobic conditions, does not appear to occur above pH 3.1. The reduction mechanisms is probably similar to the Fe(III) reduction previously documented for phenolic humic substances. Data are presented that demonstrate that Pu is at least partially associated with humic materials in ORNL soil contaminated 30 years ago with trace levels of Pu. Desorption studies using solid exchange resins also showed that, while a cation exchange resin did not desorb Pu from soil after 14 weeks equilibration, chelating resin effected Pu desorption. The desorption rate was not constant, suggesting differential Pu forms. While the resin-extractable Pu was believed to originate from solid-phase organic complexes, over 80% of the Pu in this soil was not readily resin-desorbable. This indicates that more inert soil-Pu reaction products effectively immobilize soil Pu. Some of these associations also appear to be organic. (author)

  9. Nature of complexing of glycogen with iodine in presence of CaCl2

    International Nuclear Information System (INIS)

    Bobrova, L.N.

    1986-01-01

    The absorption and dichroic absorbance of an iodine complex of muscle glycogen were studied as a function of the CaCl 2 concentration. It was found that high CaCl 2 concentrations, at which the staining of glycogen upon interaction with iodine increases sharply, destabilize the α-glucan helix and lead to a disturbance in the formation of a specific chromophore of the iodine-glycogen complex, which is indicated by the loss of dichroism. The stained chromophore appearing upon a simultaneous decrease in the dichroism is evidently produced by a nonhelical mechanism and is therefore nonspecific. This nonspecific chromophore may be the source of errors in spectrophotometric characterization of the structure of glycogens. It was shown using rabbit skeletal muscle and liver glycogens that the Krisman method, in which concentrated solutions of CaCl 2 are used, does not reveal the differences in the structure of the glycogens that are found at low CaCl 2 concentrations. The unfavorable effect of high CaCl 2 concentrations on helix formation must be kept in mind in a determination of the stoichiometry of the interaction of iodine with α-glucan

  10. Natural populations of Trypanosoma cruzi, the agent of Chagas disease, have a complex multiclonal structure

    Energy Technology Data Exchange (ETDEWEB)

    Tibayrenc, M.; Ward, P.; Moya, A.; Ayala, F.J.

    1986-01-01

    The authors have studied 15 gene loci coding for enzymes in 121 Trypanosoma cruzi stocks from a wide geographic range - from the US and Mexico to Chile and southern Brazil. T.cruzi is diploid but reproduction is basically clonal, with very little if any sexuality remaining at present. They have identified 43 different clones by their genetic composition; the same genetic clone is often found in very distant places and in diverse hosts. There is much genetic heterogeneity among the different clones, and they cannot be readily classified into a few discrete groups that might represent natural taxa. These findings imply that the biological and medical characteristics need to be ascertained separately for each natural clone. The evidence indicates that clonal evolution is very ancient in T.cruzi. The authors propose two alternative hypotheses concerning the relationship between the biochemical diversity and the heterogeneity in other biological and medical characteristics of T. cruzi. One hypothesis is that the degree of diversity between strains simply reflects the time elapsed since their last common ancestor. The second hypothesis is that biological and medical heterogeneity is recent and reflects adaptation to different transmission cycles. A decision between the two hypotheses can be reached with appropriate studies, with important medical consequences.

  11. PROCESSING OF UAV BASED RANGE IMAGING DATA TO GENERATE DETAILED ELEVATION MODELS OF COMPLEX NATURAL STRUCTURES

    Directory of Open Access Journals (Sweden)

    T. K. Kohoutek

    2012-07-01

    Full Text Available Unmanned Aerial Vehicles (UAVs are more and more used in civil areas like geomatics. Autonomous navigated platforms have a great flexibility in flying and manoeuvring in complex environments to collect remote sensing data. In contrast to standard technologies such as aerial manned platforms (airplanes and helicopters UAVs are able to fly closer to the object and in small-scale areas of high-risk situations such as landslides, volcano and earthquake areas and floodplains. Thus, UAVs are sometimes the only practical alternative in areas where access is difficult and where no manned aircraft is available or even no flight permission is given. Furthermore, compared to terrestrial platforms, UAVs are not limited to specific view directions and could overcome occlusions from trees, houses and terrain structures. Equipped with image sensors and/or laser scanners they are able to provide elevation models, rectified images, textured 3D-models and maps. In this paper we will describe a UAV platform, which can carry a range imaging (RIM camera including power supply and data storage for the detailed mapping and monitoring of complex structures, such as alpine riverbed areas. The UAV platform NEO from Swiss UAV was equipped with the RIM camera CamCube 2.0 by PMD Technologies GmbH to capture the surface structures. Its navigation system includes an autopilot. To validate the UAV-trajectory a 360° prism was installed and tracked by a total station. Within the paper a workflow for the processing of UAV-RIM data is proposed, which is based on the processing of differential GNSS data in combination with the acquired range images. Subsequently, the obtained results for the trajectory are compared and verified with a track of a UAV (Falcon 8, Ascending Technologies carried out with a total station simultaneously to the GNSS data acquisition. The results showed that the UAV's position using differential GNSS could be determined in the centimetre to the decimetre

  12. X-hitting: A new algorithm for novelty detection and dereplication by UV spectra of complex mixtures of natural products

    DEFF Research Database (Denmark)

    Hansen, Michael Edberg; Smedsgaard, Jørn; Larsen, Thomas Ostenfeld

    2005-01-01

    A major challenge in lead discovery is to detect well-known and trivial compounds rapidly, a process known as dereplication, so that isolation, structure elucidation, and pharmacological investigations can be focused on novel compounds. In this paper, we present a new algorithm, X-hitting, based...... on cross sample comparison of full UV spectra from HPLC analysis of highly complex natural product extracts/samples. X-Hitting allows automatic identification of known compounds but more important also allows finding of potentially new or similar compounds. We demonstrate this new algorithm by automatic...... identification of known structures, a task we call cross-hitting, and tentative identification of potentially new bioactive compounds, a task we call new-hitting, in HPLC data from analysis of fungal extracts. Both tasks are illustrated using 18 important reference compounds and complex fungal extracts obtained...

  13. Nonlinear Dynamics in Complex Systems Theory and Applications for the Life-, Neuro- and Natural Sciences

    CERN Document Server

    Fuchs, Armin

    2013-01-01

    With many areas of science reaching across their boundaries and becoming more and more interdisciplinary, students and researchers in these fields are confronted with techniques and tools not covered by their particular education. Especially in the life- and neurosciences quantitative models based on nonlinear dynamics and complex systems are becoming as frequently implemented as traditional statistical analysis. Unfamiliarity with the terminology and rigorous mathematics may discourage many scientists to adopt these methods for their own work, even though such reluctance in most cases is not justified.This book bridges this gap by introducing the procedures and methods used for analyzing nonlinear dynamical systems. In Part I, the concepts of fixed points, phase space, stability and transitions, among others, are discussed in great detail and implemented on the basis of example elementary systems. Part II is devoted to specific, non-trivial applications: coordination of human limb movement (Haken-Kelso-Bunz ...

  14. The complex nature of informal care in home-based heart failure management.

    Science.gov (United States)

    Clark, Alexander M; Reid, Margaret E; Morrison, Caroline E; Capewell, Simon; Murdoch, David L; McMurray, John J

    2008-02-01

    This paper is a report of a study to examine the complexities of informal caregiving for people with chronic heart failure. Little is known of the activities involved and underlying informal care. Heart failure is a common and burdensome condition in which carers play an important management role. Semi-structured interviews were carried out with 30 informal carers nominated by patients with mild-to-moderate heart failure (24 spouses, four children, one sibling and one neighbour). Interviews examined knowledge of heart failure, its effects, reported management practices and concerns, decision making and support. The data were collected in 2001. The management of heart failure was a shared and ongoing responsibility between the carer and patient. Carers' clinical knowledge of the condition and management was often limited, but they developed extensive knowledge of its personal effects on the patient. Invisible care activities included monitoring signs of symptom exacerbation and energy boundaries against perceived current and future demands and priorities. Visible care activities included medication management, dressing, bathing and help-seeking. Carers responded to patients' capacities, and adopted philosophies that sought to foster independence while facilitating as normal a life for the patient as was possible and safe. Interventions for informal carers around effective chronic heart failure management should address both visible and invisible informal caring. Future research is needed to develop interventions with carers to improve quality of care, reduce costs and improve patient quality of life. More research is needed to explore the complexities of lay caregiving and to explore the invisible dimensions of informal care further.

  15. Complexation modeling of uranium and other actinides by organic compounds of natural or synthetic origin

    International Nuclear Information System (INIS)

    Bouby, M.

    1998-01-01

    The behaviour of nuclear wastes raises many questions, the answers of which require a precise knowledge of the physical, chemical and biological processes affecting the properties of the radio-elements present in the wastes. Three ways of research are approached. The results obtained give some elements of answer to these questions. The experimental methods that have been used are the neutron activation analysis, the UV-visible spectrophotometry, and the time-resolved laser spectro-fluorimetry. The analysis of the results has permitted to model part of the phenomena evidenced by using suitable ionic force correction models (Davies or MSA type) when chemical equilibria have been considered. The main results show: the bio-sorption capacities of Mycobacterium phlei microorganism with respect to UO 2 2+ and NpO 2+ cations such as: Q eq (UO 2 2+ ) = 60 and Q eq (NpO 2+ ) = 444 moles of cation per g of dry biomass; the retention capacities, in various leaching conditions, of this bacteria of the preliminarily adsorbed ions; the complexation properties of two siderophores with respect to UO 2 2+ , U 4+ and Th 4+ cations. One siderophore, Pyoverdine A, shows a selectiveness which is explained by the value of the thermodynamic equilibrium constant determined for each cation using the same model: K(UO 2 2+ ) 4+ ) 4+ ). The behaviour in highly acid environment (HCl and HClO 4 up to 12 M) of acylisoxazolone HPBI (1-phenyl-4-benzoyl-5-isoxazolone) and the value of its acidity thermodynamical constant (0.13 th 4 and CF 3 SO 3 H up to 12 M). It seems that a complexation between uranyl and the counter-ions present in the solution occurs. (J.S.)

  16. Complexation modelling of uranium and other actinides by organic compounds of natural or synthetic origin

    International Nuclear Information System (INIS)

    Bouby, M.

    1998-01-01

    The future of nuclear wastes raises a lot of questions. Their resolution require an accurate knowledge of the physical, chemical and biological processes which affect the properties of radioelements constituting the wastes. 3 research themes have been approached. The experimental methods used are: neutronic activation analysis, UV-visible spectrophotometry and time-resolved induced laser spectro-fluorimetry. A part of the phenomena has been modelled by ionic strength correction models (as Davies or MSA). The main results have revealed: 1)the bio-sorption capacities of the microorganism (Mycobacterium phlei) for UO 2 2+ and NpO 2+ (in conditions where the specific adsorption capacities Qe(UO 2 2+ )=60 and Qe(NpO 2+ )=444 moles cations/g dry biomass 2)the retention capacities, in various leaching conditions, by this bacteria of the ions initially adsorbed 3)the complexation properties of 2 siderophores for the cations UO 2 2+ , U 4+ and Th 4+ . The thermodynamical equilibrium constants were determined for one of the siderophore: the pyoverdine A; they were such that KUO 2 2+ ≤KU 4+ ≤KTh 4+ 4)in very acidic media (HCl and HClO 4 until 12 M), the behaviour of the acylisoxazolone HPBI (1-phenyl-4-benzoyl-5-isoxazolone) and the value of its acidity thermodynamical constant is such that 0.13≤KATh≤0.32 at 25 degrees Celsius 5)the variations of the fluorescence properties of the uranyl cation in terms of the acidity of the concentrated media (HClO 4 and CF 3 SO 3 H) in which they are in solution; it seems that a complexation between the uranyl ion and the counter-ions present in solution occur. (O.M.)

  17. Formation of protein complex with the aid of polyethylene glycol for deproteinized natural rubber latex

    Science.gov (United States)

    Wei, Lim Keuw; Ing, Wong Kwee; Badri, Khairiah Haji; Ban, Wong Chong

    2013-11-01

    The effect of polyethylene glycol (PEG) as a deproteinizing agent in commercial natural rubber latex (NRL) onto the physicochemical properties of the NRL was investigated. Three types of PEG were used namely PEG200, PEG4000 and PEG20000 (molecular weight of 200, 4000 and 20000 g/mol respectively). The optimum amount of PEG in NRL was determined from viscosity changes, protein content and Fourier Transform Infrared spectroscopy. Level of protein reduction was affected by molecular weight of PEG. The addition of PEG in NRL reduced the protein content of NRL (3.30 %) to the lowest (2.01 %) at 0.40 phr of PEG200 due to more attractive hydrophobic interactions between short chains PEG compared to PEG4000 (2.24%) and PEG20000 (2.15%). This was verified through FTIR spectroscopy analysis by observing the primary and secondary amide peak where PEG4000 has lesser absorption at the region compared to with PEG20000.

  18. The biotic factors role in radionuclide migration of natural-vegetable complexes

    International Nuclear Information System (INIS)

    Yakushev, B.I.; Kazej, A.I.; Sak, M.M.; Kuz'mich, O.T.; Golushko, R.M.

    1992-01-01

    In Byelorussiyn from first months after the Chernobyl' accident investigation are conducting on the radionuclide de dynamics in the soil-plant-soil system. The isotope composition of soil contamination density and specific plants radioactivity are studying, the radionuclide migration dynamic through the soil profile is investigating. The data are shown on considerable reduction of the plants radioactivity (1986-91 years) in connection with the reduction in the soil contamination density with gamma-spectrum radionuclides, accounting for Ce-144, Pr-144, Ru-106, Cs-134 decay; information is done on gamma-spectrum radionuclides of organs in natural pine and meadows system. It is shown, that the radionuclides are actively absorbed by roots in a zone of the highest radionuclide concentration and are delivered into the overground plant parts, then actively are removed into environment in the breathing process. 11 refs.; 4 tabs

  19. Laboratory Investigation of Complex Conductivity and Magnetic Susceptibility on Natural Iron Oxide Coated Sand

    Science.gov (United States)

    Wang, C.; Slater, L. D.; Day-Lewis, F. D.; Briggs, M. A.

    2017-12-01

    Redox reactions occurring at the oxic/anoxic interface where groundwater discharges to surface water commonly result in iron oxide deposition that coats sediment grains. With relatively large total surface area, these iron oxide coated sediments serve as a sink for sorption of dissolved contaminants, although this sink may be temporary if redox conditions fluctuate with varied flow conditions. Characterization of the distribution of iron oxides in streambed sediments could provide valuable understanding of biogeochemical reactions and the ability of a natural system to sorb contaminants. Towards developing a field methodology, we conducted laboratory spectral induced polarization (SIP) and magnetic susceptibility (MS) measurements on natural iron oxide coated sand (Fe-sand) with grain sizes ranging from 0.3 to 2.0 mm in order to assess the sensitivity of these measurements to iron oxides in sediments. The Fe-sand was also sorted by sieving into various grain sizes to study the impact of grain size on the polarization mechanisms. The unsorted Fe-sand saturated with 0.01 S/m NaCl solution exhibited a distinct phase response ( > 4 mrad) in the frequency range from 0.001 to 100 Hz whereas regular silica sand was characterized by a phase response less than 1 mrad under the same conditions. The presence of iron oxide substantially increased MS (3.08×10-3 SI) over that of regular sand ( Laboratory results demonstrated that SIP and MS may be well suited to mapping the distribution of iron oxides in streambed sediments associated with anoxic groundwater discharge.

  20. Unique Nature of the Quality of Life in the Context of Extreme Climatic, Geographical and Specific Socio-Cultural Living Conditions

    Science.gov (United States)

    Kulik, Anastasia; Neyaskina, Yuliya; Frizen, Marina; Shiryaeva, Olga; Surikova, Yana

    2016-01-01

    This article presents the results of a detailed empirical research, aimed at studying the quality of life in the context of extreme climatic, geographical and specific sociocultural living conditions. Our research is based on the methodological approach including social, economical, ecological and psychological characteristics and reflecting…

  1. Absolute band structure determination on naturally occurring rutile with complex chemistry: Implications for mineral photocatalysis on both Earth and Mars

    Science.gov (United States)

    Li, Yan; Xu, Xiaoming; Li, Yanzhang; Ding, Cong; Wu, Jing; Lu, Anhuai; Ding, Hongrui; Qin, Shan; Wang, Changqiu

    2018-05-01

    Rutile is the most common and stable form of TiO2 that ubiquitously existing on Earth and other terrestrial planets like Mars. Semiconducting mineral such as rutile-based photoredox reactions have been considered to play important roles in geological times. However, due to the inherent complexity in chemistry, the precision determination on band structure of natural rutile and the theoretical explanation on its solar-driven photochemistry have been hardly seen yet. Considering the multiple minor and trace elements in natural rutile, we firstly obtained the single-crystal crystallography, mineralogical composition and defects characteristic of the rutile sample by using both powder and single crystal X-ray diffraction, electron microprobe analysis and X-ray photoelectron spectroscopy. Then, the band gap was accurately determined by synchrotron-based O K-edge X-ray absorption and emission spectra, which was firstly applied to natural rutile due to its robustness on compositions and defects. The absolute band edges of the rutile sample was calculated by considering the electronegativity of the atoms, band gap and point of zero charge. Besides, after detecting the defect energy levels by photoluminescence spectra, we drew the schematic band structure of natural rutile. The band gap (2.7 eV) of natural rutile was narrower than that of synthetic rutile (3.0 eV), and the conduction and valence band edges of natural rutile at pH = pHPZC were determined to be -0.04 V and 2.66 V (vs. NHE), respectively. The defect energy levels located at nearly the middle position of the forbidden band. Further, we used theoretical calculations to verify the isomorphous substitution of Fe and V for Ti gave rise to the distortion of TiO6 octahedron and created vacancy defects in natural rutile. Based on density functional theory, the narrowed band gap was interpreted to the contribution of Fe-3d and V-3d orbits, and the defect energy state was formed by hybridization of O-2p and Fe/V/Ti-3d

  2. Liquid Membranes as a Tool for Chemical Speciation of Metals in Natural Waters: Organic and Inorganic Complexes of Nickel.

    Science.gov (United States)

    Vergel, Cristina; Mendiguchía, Carolina; Moreno, Carlos

    2018-04-15

    The different species of nickel present in natural waters exhibit different transport behaviour through bulk liquid membranes (BLMs). This fact has been used to design and optimise a separation/pre-concentration system applicable to separate labile and non-labile nickel fractions. A hydrazone derivative-1,2-cyclohexanedione bis-benzoyl-hydrazone (1,2-CHBBH) dissolved in toluene/dimethyl formamide (2% DMF)-was used as a chemical carrier of nickel species, from an aqueous source solution (sample) to a receiving acidic solution. Both chemical and hydrodynamic conditions controlling the transport system were studied and optimised. Under optimum conditions, variations in the transport of nickel ions as a function of organic (humic acids) and inorganic (chloride ions) ligands were studied. Relationships between the permeability coefficient ( P ) or recovery efficiency (%R) and the concentrations of ligands and nickel species were analysed using Winhumic V software. A negative correlation between P and the concentration of organic nickel complexes was found, suggesting that only labile nickel species are transported through the liquid membrane, with non-labile complexes remaining in the water sample; allowing for their separation and subsequent quantification in natural waters.

  3. A flexible object-based software framework for modeling complex systems with interacting natural and societal processes.

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, J. H.

    2000-06-15

    The Dynamic Information Architecture System (DIAS) is a flexible, extensible, object-based framework for developing and maintaining complex multidisciplinary simulations. The DIAS infrastructure makes it feasible to build and manipulate complex simulation scenarios in which many thousands of objects can interact via dozens to hundreds of concurrent dynamic processes. The flexibility and extensibility of the DIAS software infrastructure stem mainly from (1) the abstraction of object behaviors, (2) the encapsulation and formalization of model functionality, and (3) the mutability of domain object contents. DIAS simulation objects are inherently capable of highly flexible and heterogeneous spatial realizations. Geospatial graphical representation of DIAS simulation objects is addressed via the GeoViewer, an object-based GIS toolkit application developed at ANL. DIAS simulation capabilities have been extended by inclusion of societal process models generated by the Framework for Addressing Cooperative Extended Transactions (FACET), another object-based framework developed at Argonne National Laboratory. By using FACET models to implement societal behaviors of individuals and organizations within larger DIAS-based natural systems simulations, it has become possible to conveniently address a broad range of issues involving interaction and feedback among natural and societal processes. Example DIAS application areas discussed in this paper include a dynamic virtual oceanic environment, detailed simulation of clinical, physiological, and logistical aspects of health care delivery, and studies of agricultural sustainability of urban centers under environmental stress in ancient Mesopotamia.

  4. Liquid Membranes as a Tool for Chemical Speciation of Metals in Natural Waters: Organic and Inorganic Complexes of Nickel

    Directory of Open Access Journals (Sweden)

    Cristina Vergel

    2018-04-01

    Full Text Available The different species of nickel present in natural waters exhibit different transport behaviour through bulk liquid membranes (BLMs. This fact has been used to design and optimise a separation/pre-concentration system applicable to separate labile and non-labile nickel fractions. A hydrazone derivative—1,2-cyclohexanedione bis-benzoyl-hydrazone (1,2-CHBBH dissolved in toluene/dimethyl formamide (2% DMF—was used as a chemical carrier of nickel species, from an aqueous source solution (sample to a receiving acidic solution. Both chemical and hydrodynamic conditions controlling the transport system were studied and optimised. Under optimum conditions, variations in the transport of nickel ions as a function of organic (humic acids and inorganic (chloride ions ligands were studied. Relationships between the permeability coefficient (P or recovery efficiency (%R and the concentrations of ligands and nickel species were analysed using Winhumic V software. A negative correlation between P and the concentration of organic nickel complexes was found, suggesting that only labile nickel species are transported through the liquid membrane, with non-labile complexes remaining in the water sample; allowing for their separation and subsequent quantification in natural waters.

  5. Complex Systems Education for natural Hazards and from down to up Pushing of Government and Officials: A Case Study

    Science.gov (United States)

    Zvelebil, J.

    2009-04-01

    There is no point to discuss necessity of knowledge of Complex System or Nonlinear Science sensu lato at all education levels and practical decision making. Author feels that fulfilling of this strategic task needs to apply three tactics. However, each of them possesses different urgency. The highest priority has extensive education of new alternative paradigm for students. The reason is, study of Natural Science is highly fragmented into too one-theme-narrowly aimed specializations at Czech Universities. Common introductions into general methodology of science are unfortunately old fashioned, if any. They stress regular, reductionist, and time-less paradigm of classical physics without any alternatives, even the one of quantum theory by statistical physics. According former, our world is full of passive, simple, material items, which are being displaced, dragged, and changed (reversibly) by outer forces. Their interplays gradually, reaching one-by one higher levels of causal organization - all levels with the same types of canonical description, finally form the visible macro-reality. This view is in direct contradiction with student's personal experience. They see their World full of self-sustaining items actively using to that their own, inner intrinsic mechanisms. From molecules up, they are not simple things. In contrary, they are highly organized, and are even further organizing themselves into higher complexes by rich mutual interactions. In biology, those items are even caring-about-themselves entities, which actively survey and manipulate their outer environment to gain energy to increase their organization. Moreover, unhappy students are facing common view there is no "hard science" without being able to reduce results of their scientific work into a few mathematical equations, by which the observed "fata morgana" is reduced into "really scientific" description by "basic rules of Nature", which, hidden behind the scene, are causes of all the observed

  6. Thermodynamics of inclusion complexes of natural and modified cyclodextrins with acetylsalicylic acid and ibuprofen in aqueous solution at 298 K

    Energy Technology Data Exchange (ETDEWEB)

    Castronuovo, Giuseppina, E-mail: giuseppina.castronuovo@unina.it [Department of Chemistry, University Federico II of Naples, Complesso Universitario a Monte S. Angelo, via Cintia, 80126 Naples (Italy); Niccoli, Marcella [Department of Chemistry, University Federico II of Naples, Complesso Universitario a Monte S. Angelo, via Cintia, 80126 Naples (Italy)

    2013-04-10

    Graphical abstract: Complexation forces acting in the association between natural and modified α- and β-cyclodextrins and acetylsalicylic acid (aspirin) or ibuprofen are examined through the analysis of the thermodynamic parameters obtained by isothermal calorimetry. Highlights: ► A calorimetric method is reported to study the association of natural and substituted cyclodextrins with acetylsalicylic acid and ibuprofen. ► The study aims to propose a hypothesis about the forces involved in the interaction. That can be useful for designing new cyclodextrins having suitable characteristics to include specific drugs. ► Enthalpic and entropic contributions on the association are discussed. The differences in the cavity dimensions of the cyclodextrins determine the values of the thermodynamic properties to be very different. - Abstract: Thermodynamic parameters for the association of natural and substituted α-, β-, and γ-cyclodextrins with acetylsalicylic acid, salicylic acid and ibuprofen have been determined by isothermal titration calorimetry. Analysis of the data shows that complexes form, all having 1:1 stoichiometry. The shape-matching between the host and guest is the factor determining the values of the thermodynamic quantities. In the case of the smallest cyclodextrin interacting with acetylsalicylic acid and salicylic acid, the parameters indicate that hydrophobic interactions play the major role. Association occurs through the shallow inclusion of the benzene ring into the cavity. In the case of substituted β-cyclodextrins, instead, inclusion of the benzene ring is deeper and the tight fitting of the guest molecule to the cavity makes the enthalpy and entropy to be both negative. Ibuprofen interacts through its isobutyl group: the values of the association constants are very high for β-cyclodextrins as determined by the large and positive entropies due to the relaxation of water molecules from the cavity and the hydration spheres of the interacting

  7. Thermodynamics of inclusion complexes of natural and modified cyclodextrins with acetylsalicylic acid and ibuprofen in aqueous solution at 298 K

    International Nuclear Information System (INIS)

    Castronuovo, Giuseppina; Niccoli, Marcella

    2013-01-01

    Graphical abstract: Complexation forces acting in the association between natural and modified α- and β-cyclodextrins and acetylsalicylic acid (aspirin) or ibuprofen are examined through the analysis of the thermodynamic parameters obtained by isothermal calorimetry. Highlights: ► A calorimetric method is reported to study the association of natural and substituted cyclodextrins with acetylsalicylic acid and ibuprofen. ► The study aims to propose a hypothesis about the forces involved in the interaction. That can be useful for designing new cyclodextrins having suitable characteristics to include specific drugs. ► Enthalpic and entropic contributions on the association are discussed. The differences in the cavity dimensions of the cyclodextrins determine the values of the thermodynamic properties to be very different. - Abstract: Thermodynamic parameters for the association of natural and substituted α-, β-, and γ-cyclodextrins with acetylsalicylic acid, salicylic acid and ibuprofen have been determined by isothermal titration calorimetry. Analysis of the data shows that complexes form, all having 1:1 stoichiometry. The shape-matching between the host and guest is the factor determining the values of the thermodynamic quantities. In the case of the smallest cyclodextrin interacting with acetylsalicylic acid and salicylic acid, the parameters indicate that hydrophobic interactions play the major role. Association occurs through the shallow inclusion of the benzene ring into the cavity. In the case of substituted β-cyclodextrins, instead, inclusion of the benzene ring is deeper and the tight fitting of the guest molecule to the cavity makes the enthalpy and entropy to be both negative. Ibuprofen interacts through its isobutyl group: the values of the association constants are very high for β-cyclodextrins as determined by the large and positive entropies due to the relaxation of water molecules from the cavity and the hydration spheres of the interacting

  8. A spectroscopic and computational study of Al(III) complexes in cryolite melts: Effect of cation nature

    International Nuclear Information System (INIS)

    Nazmutdinov, Renat R.; Zinkicheva, Tamara T.; Vassiliev, Sergey Yu.; Glukhov, Dmitrii V.; Tsirlina, Galina A.; Probst, Michael

    2013-01-01

    Highlights: ► We investigate Li, Na and K cryolite melts by Raman spectroscopy and dft. ► A slight red shift of main Raman peaks is observed in the row Li + , Na + , K + . ► A decrease of the half-widths of peaks is observed in the same row. ► Fluoroaluminates and their complexation kinetics play an important role. - Abstract: Lithium, sodium and potassium cryolite melts are probed by Raman spectroscopy in a wide range of the melt composition. The experimental data demonstrate a slight red shift of main peaks and a decrease of their half-widths in the row Li + , Na + , K + . Quantum chemical modelling of the systems is performed at the density functional theory level. The ionic environment is found to play a crucial role in the energy of fluoroaluminates. Potential energy surfaces describing the formation/dissociation of certain complex species, as well as model Raman spectra are constructed and compared with those obtained recently for sodium containing cryolite melts (R.R. Nazmutdinov, et al., Spectrochim, Acta A 75 (2010) 1244.). The calculations show that the cation nature affects the geometry of the ionic associates as well as the equilibrium and kinetics of the complexation processes. This enables to interpret both original experimental data and those reported in literature

  9. The complex nature of mixed farming systems requires multidimensional actions supported by integrative research and development efforts.

    Science.gov (United States)

    González-García, E; Gourdine, J L; Alexandre, G; Archimède, H; Vaarst, M

    2012-05-01

    Mixed farming systems (MFS) have demonstrated some success by focusing on the use of integrative and holistic mechanisms, and rationally building on and using the natural and local resource base without exhausting it, while enhancing biodiversity, optimizing complementarities between crops and animal systems and finally increasing opportunities in rural livelihoods. Focusing our analysis and discussion on field experiences and empirical knowledge in the Caribbean islands, this paper discusses the opportunities for a change needed in current MFS research-development philosophy. The importance of shifting from fragile/specialized production systems to MFS under current global conditions is argued with an emphasis on the case of Small Islands Developing States (SIDS) and the Caribbean. Particular vulnerable characteristics as well as the potential and constraints of SIDS and their agricultural sectors are described, while revealing the opportunities for the 'richness' of the natural and local resources to support authentic and less dependent production system strategies. Examples are provided of the use of natural grasses, legumes, crop residues and agro-industrial by-products. We analyse the requirement for a change in research strategies and initiatives through the development of a complex but necessary multi-/inter-/trans-disciplinary teamwork spirit. We stress as essential the collaboration and active participation of local and regional actors, stakeholders and end-users in the identification of research priorities, as well as the generation, exchange and dissemination of knowledge and technology innovations, while strengthening the leadership roles in the conduct of integrative and participative research and development projects.

  10. IMPROVED ALGORITHM FOR CALCULATING COMPLEX NON-EQUIPOTENTIAL GROUNDING DEVICES OF ELECTRICAL INSTALLATIONS TAKING INTO ACCOUNT CONDUCTIVITY OF NATURAL GROUNDINGS

    Directory of Open Access Journals (Sweden)

    K. A. Starkov

    2017-08-01

    Full Text Available Purpose. The method of natural concentrated groundings substitution by the set of electrodes taking them into account in the algorithm of electric characteristics calculation for complicated grounding connections of electric installation is offered. An equivalent model as a set of linear electrodes is chosen in accordance with two criteria: leakage resistance and potentials on the ground surface. Methodology. We have applied induced potential method and methods for computing branched electrical circuits with distributed parameters. Results. We have obtained the algorithm for calculating complex non-equipotential grounding connections, which makes it possible to obtain refined values of the potential distribution in the electric stations and substations with outdoor switchgear. Originality. For the first time, we have taking into account the conductivity of natural concentrated grounds by a set of vertical and horizontal electrodes based on equivalent electrical characteristics applied to a two-layer ground. Practical value. The using of the proposed calculation algorithm in the electric grids of JSC «Kharkivoblenergo» made it possible to determine the values of the potential distribution at short circuit in electrical substation taking into account the influence of the conductivity of natural concentrated groundings.

  11. Influence of the extreme millennial values of the physical data of the natural environment on the ground and near underground. Application to waste disposal sites

    International Nuclear Information System (INIS)

    Guinle-Thenevin, I.

    1998-01-01

    This study deals with effects of extreme climatic events in France on perenniality of radioactive or toxic waste disposal coverings or of tailing storage barriers. Three phenomena are quantified: erosion or scraping produced by storm showers, ground freezing depth caused by harsh winters and ground drying resulted from arid summers. To quantify this phenomena, we need statistical evaluation of the climatic events (erosivity of rain showers, frost severity index, drought severity indices), a study of the soil characteristics (petrography, thermal and hydraulic properties) and numeric models of soils (finite elements or finite differences methods). Last but not least, each method is applied to French sites chosen for their climate and their proximity to real or possible storage. Therefore, we show critical parameters for the design of waste disposal covering which takes into account extreme climatic events. (author)

  12. A phylogenetic and cognitive perspective on linguistic complexity ...

    African Journals Online (AJOL)

    In recent years a growing interest in the nature of linguistic complexity has emerged in linguistic circles. A striking feature of this interest is that linguistic complexity is taken to be a phenomenon in its own right. In fact, an extreme construal of the inherent complexity of language is represented in the notion of universal ...

  13. Acclimatization to extreme heat

    Science.gov (United States)

    Warner, M. E.; Ganguly, A. R.; Bhatia, U.

    2017-12-01

    Heat extremes throughout the globe, as well as in the United States, are expected to increase. These heat extremes have been shown to impact human health, resulting in some of the highest levels of lives lost as compared with similar natural disasters. But in order to inform decision makers and best understand future mortality and morbidity, adaptation and mitigation must be considered. Defined as the ability for individuals or society to change behavior and/or adapt physiologically, acclimatization encompasses the gradual adaptation that occurs over time. Therefore, this research aims to account for acclimatization to extreme heat by using a hybrid methodology that incorporates future air conditioning use and installation patterns with future temperature-related time series data. While previous studies have not accounted for energy usage patterns and market saturation scenarios, we integrate such factors to compare the impact of air conditioning as a tool for acclimatization, with a particular emphasis on mortality within vulnerable communities.

  14. Analyzing discourse and text complexity for learning and collaborating a cognitive approach based on natural language processing

    CERN Document Server

    Dascălu, Mihai

    2014-01-01

    With the advent and increasing popularity of Computer Supported Collaborative Learning (CSCL) and e-learning technologies, the need of automatic assessment and of teacher/tutor support for the two tightly intertwined activities of comprehension of reading materials and of collaboration among peers has grown significantly. In this context, a polyphonic model of discourse derived from Bakhtin’s work as a paradigm is used for analyzing both general texts and CSCL conversations in a unique framework focused on different facets of textual cohesion. As specificity of our analysis, the individual learning perspective is focused on the identification of reading strategies and on providing a multi-dimensional textual complexity model, whereas the collaborative learning dimension is centered on the evaluation of participants’ involvement, as well as on collaboration assessment. Our approach based on advanced Natural Language Processing techniques provides a qualitative estimation of the learning process and enhance...

  15. The natural catalytic function of CuGE glucuronoyl esterase in hydrolysis of genuine lignin-carbohydrate complexes from birch

    DEFF Research Database (Denmark)

    Mosbech, Caroline; Holck, Jesper; Meyer, Anne S.

    2018-01-01

    Glucuronoyl esterases belong to carbohydrate esterase family 15 and catalyze de-esterification. Their natural function is presumed to be cleavage of ester linkages in lignin-carbohydrate complexes particularly those linking lignin and glucuronoyl residues in xylans in hardwood. Here, we show...... for the first time a detailed product profile of aldouronic acids released from birchwood lignin by a glucuronoyl esterase from the white-rot fungus Cerrena unicolor (CuGE). CuGE releases substrate for GH10 endo-xylanase which results in significantly increased product release compared to the action of endo......-xylanase alone. CuGE also releases neutral xylo-oligosaccharides that can be ascribed to the enzymes feruloyl esterase side activity as demonstrated by release of ferulic acid from insoluble wheat arabinoxylan. The data verify the enzyme's unique ability to catalyze removal of all glucuronoxylan associated...

  16. Molecular modeling of human acidic mammalian chitinase in complex with the natural-product cyclopentapeptide chitinase inhibitor argifin.

    Science.gov (United States)

    Gouda, Hiroaki; Terashima, Shinichi; Iguchi, Kanami; Sugawara, Akihiro; Saito, Yoshifumi; Yamamoto, Tsuyoshi; Hirose, Tomoyasu; Shiomi, Kazuro; Sunazuka, Toshiaki; Omura, Satoshi; Hirono, Shuichi

    2009-09-01

    Human acidic mammalian chitinase (hAMCase) is an attractive target for developing anti-asthma medications. We used a variety of computational methods to investigate the interaction between hAMCase and the natural-product cyclopentapeptide chitinase inhibitor argifin. The three-dimensional structure of hAMCase was first constructed using homology modeling. The interaction mode and binding free energy between argifin and hAMCase were then examined by the molecular-docking calculation and the molecular mechanics Poisson-Boltzmann surface area method combined with molecular dynamics simulation, respectively. The results suggested that argifin binds to hAMCase in a similar fashion to the interaction mode observed in the crystal structure of argifin-human chitotriosidase complex, and possesses inhibitory activity against hAMCase in the micromolar range. We further designed argifin derivatives expected to be selective for hAMCase.

  17. A shift in nuclear state as the result of natural interspecific hybridization between two North American taxa of the basidiomycete complex Heterobasidion

    Science.gov (United States)

    Matteo Garbelotto; Paolo Gonthier; Rachel Linzer; Giovanni Nicolotti; William Otrosina

    2004-01-01

    A natural first generation hybrid fungus shows interspecific heterozygosity. The nuclear condition of a rare natural hybrid between two taxa of the Heterobasidion complex is investigated. Heterobasidion species are known to be either homokaryotic (haploid) or heterokaryotic (n + n), but heterokaryons are made up of both...

  18. The Nature of Conceptual Understanding in Biomedicine: The Deep Structure of Complex Ideas and the Development of Misconceptions. Technical Report No. 440.

    Science.gov (United States)

    Feltovich, Paul J.; And Others

    This report presents a general framework for studying the acquisition and cognitive representation of biomedical concepts and analyzing the nature and development of misconceptions. The central approach of the report is a selective and highly concentrated analysis of the true nature of clusters of complex concepts and the manner in which they are…

  19. Performance evaluation of functioning of natural-industrial system of mining-processing complex with help of analytical and mathematical models

    Science.gov (United States)

    Bosikov, I. I.; Klyuev, R. V.; Revazov, V. Ch; Pilieva, D. E.

    2018-03-01

    The article describes research and analysis of hazardous processes occurring in the natural-industrial system and effectiveness assessment of its functioning using mathematical models. Studies of the functioning regularities of the natural and industrial system are becoming increasingly relevant in connection with the formulation of the task of modernizing production and the economy of Russia as a whole. In connection with a significant amount of poorly structured data, it is complicated by regulations for the effective functioning of production processes, social and natural complexes, under which a sustainable development of the natural-industrial system of the mining and processing complex would be ensured. Therefore, the scientific and applied problems, the solution of which allows one to formalize the hidden structural functioning patterns of the natural-industrial system and to make managerial decisions of organizational and technological nature to improve the efficiency of the system, are very relevant.

  20. Tetra- and hexavalent uranium forms bidentate-mononuclear complexes with particulate organic matter in a naturally uranium-enriched peatland

    International Nuclear Information System (INIS)

    Mikutta, Christian; Langner, Peggy; Bargar, John R.; Kretzschmar, Ruben

    2016-01-01

    Peatlands frequently serve as efficient biogeochemical traps for U. Mechanisms of U immobilization in these organic matter-dominated environments may encompass the precipitation of U-bearing mineral(oid)s and the complexation of U by a vast range of (in)organic surfaces. The objective of this work was to investigate the spatial distribution and molecular binding mechanisms of U in soils of an alpine minerotrophic peatland (pH 4.7–6.6, E_h = –127 to 463 mV) using microfocused X-ray fluorescence spectrometry and bulk and microfocused U L_3-edge X-ray absorption spectroscopy. The soils contained 2.3–47.4 wt % organic C, 4.1–58.6 g/kg Fe, and up to 335 mg/kg geogenic U. Uranium was found to be heterogeneously distributed at the micrometer scale and enriched as both U(IV) and U(VI) on fibrous and woody plant debris (48 ± 10% U(IV), x̄ ± σ, n = 22). Bulk U X-ray absorption near edge structure (XANES) spectroscopy revealed that in all samples U(IV) comprised 35–68% of total U (x̄ = 50%, n = 15). Shell-fit analyses of bulk U L_3-edge extended X-ray absorption fine structure (EXAFS) spectra showed that U was coordinated to 1.3 ± 0.2 C atoms at a distance of 2.91 ± 0.01 Å (x̄ ± σ), which implies the formation of bidentate-mononuclear U(IV/VI) complexes with carboxyl groups. We neither found evidence for U shells at ~3.9 Å, indicative of mineral-associated U or multinuclear U(IV) species, nor for a substantial P/Fe coordination of U. As a result, our data indicates that U(IV/VI) complexation by natural organic matter prevents the precipitation of U minerals as well as U complexation by Fe/Mn phases at our field site, and suggests that organically complexed U(IV) is formed via reduction of organic matter-bound U(VI).

  1. Tetra- and Hexavalent Uranium Forms Bidentate-Mononuclear Complexes with Particulate Organic Matter in a Naturally Uranium-Enriched Peatland.

    Science.gov (United States)

    Mikutta, Christian; Langner, Peggy; Bargar, John R; Kretzschmar, Ruben

    2016-10-04

    Peatlands frequently serve as efficient biogeochemical traps for U. Mechanisms of U immobilization in these organic matter-dominated environments may encompass the precipitation of U-bearing mineral(oid)s and the complexation of U by a vast range of (in)organic surfaces. The objective of this work was to investigate the spatial distribution and molecular binding mechanisms of U in soils of an alpine minerotrophic peatland (pH 4.7-6.6, E h = -127 to 463 mV) using microfocused X-ray fluorescence spectrometry and bulk and microfocused U L 3 -edge X-ray absorption spectroscopy. The soils contained 2.3-47.4 wt % organic C, 4.1-58.6 g/kg Fe, and up to 335 mg/kg geogenic U. Uranium was found to be heterogeneously distributed at the micrometer scale and enriched as both U(IV) and U(VI) on fibrous and woody plant debris (48 ± 10% U(IV), x̅ ± σ, n = 22). Bulk U X-ray absorption near edge structure (XANES) spectroscopy revealed that in all samples U(IV) comprised 35-68% of total U (x̅ = 50%, n = 15). Shell-fit analyses of bulk U L 3 -edge extended X-ray absorption fine structure (EXAFS) spectra showed that U was coordinated to 1.3 ± 0.2 C atoms at a distance of 2.91 ± 0.01 Å (x̅ ± σ), which implies the formation of bidentate-mononuclear U(IV/VI) complexes with carboxyl groups. We neither found evidence for U shells at ∼3.9 Å, indicative of mineral-associated U or multinuclear U(IV) species, nor for a substantial P/Fe coordination of U. Our data indicates that U(IV/VI) complexation by natural organic matter prevents the precipitation of U minerals as well as U complexation by Fe/Mn phases at our field site, and suggests that organically complexed U(IV) is formed via reduction of organic matter-bound U(VI).

  2. Endocrine-Disrupting Chemicals and Oil and Natural Gas Operations: Potential Environmental Contamination and Recommendations to Assess Complex Environmental Mixtures.

    Science.gov (United States)

    Kassotis, Christopher D; Tillitt, Donald E; Lin, Chung-Ho; McElroy, Jane A; Nagel, Susan C

    2016-03-01

    Hydraulic fracturing technologies, developed over the last 65 years, have only recently been combined with horizontal drilling to unlock oil and gas reserves previously deemed inaccessible. Although these technologies have dramatically increased domestic oil and natural gas production, they have also raised concerns for the potential contamination of local water supplies with the approximately 1,000 chemicals that are used throughout the process, including many known or suspected endocrine-disrupting chemicals. We discuss the need for an endocrine component to health assessments for drilling-dense regions in the context of hormonal and antihormonal activities for chemicals used. We discuss the literature on a) surface and groundwater contamination by oil and gas extraction operations, and b) potential human exposure, particularly in the context of the total hormonal and antihormonal activities present in surface and groundwater from natural and anthropogenic sources; we also discuss initial analytical results and critical knowledge gaps. In light of the potential for environmental release of oil and gas chemicals that can disrupt hormone receptor systems, we recommend methods for assessing complex hormonally active environmental mixtures. We describe a need for an endocrine-centric component for overall health assessments and provide information supporting the idea that using such a component will help explain reported adverse health trends as well as help develop recommendations for environmental impact assessments and monitoring programs.

  3. Structural Complexity and Ecosystem Functions in a Natural Mixed Forest under a Single-Tree Selection Silviculture

    Directory of Open Access Journals (Sweden)

    Toshiya Yoshida

    2017-11-01

    Full Text Available The objective of forest management has become broader, and it is essential to harmonize timber production with conservation of the forest ecosystem. Selection cutting is recognized as a major alternative of clear-cutting, because it can maintain the complexity and heterogeneity of a natural forest; however, its long-term evaluations are limited. This study compared various attributes of stand structures, which are indicators of biodiversity and ecosystem carbon stock between managed and unmanaged blocks (12.6 ha area in total in a natural mixed forest in Hokkaido, the northernmost island of Japan. We found that 30 years’ implementation of single-tree selection did not affect the volume, size structure, species diversity nor spatial distribution of overstory trees in the managed stands. Also, the total carbon stock in the managed stands was almost equal to that of the unmanaged stands. In contrast, several structural attributes and indicator elements that are significant for biodiversity (such as large-diameter live trees, dead trees, cavities, epiphytic bryophytes, and some avian guilds showed marked decrease in the managed stands. We conclude that it is required to leave these structures and elements to some extent for deriving the merit of the management as an alternative silvicultural regime in the region.

  4. Curvilinear immersed-boundary method for simulating unsteady flows in shallow natural streams with arbitrarily complex obstacles

    Science.gov (United States)

    Kang, Seokkoo; Borazjani, Iman; Sotiropoulos, Fotis

    2008-11-01

    Unsteady 3D simulations of flows in natural streams is a challenging task due to the complexity of the bathymetry, the shallowness of the flow, and the presence of multiple nature- and man-made obstacles. This work is motivated by the need to develop a powerful numerical method for simulating such flows using coherent-structure-resolving turbulence models. We employ the curvilinear immersed boundary method of Ge and Sotiropoulos (Journal of Computational Physics, 2007) and address the critical issue of numerical efficiency in large aspect ratio computational domains and grids such as those encountered in long and shallow open channels. We show that the matrix-free Newton-Krylov method for solving the momentum equations coupled with an algebraic multigrid method with incomplete LU preconditioner for solving the Poisson equation yield a robust and efficient procedure for obtaining time-accurate solutions in such problems. We demonstrate the potential of the numerical approach by carrying out a direct numerical simulation of flow in a long and shallow meandering stream with multiple hydraulic structures.

  5. Endocrine-disrupting chemicals and oil and natural gas operations: Potential environmental contamination and recommendations to assess complex environmental mixtures

    Science.gov (United States)

    Kassotis, Christopher D.; Tillitt, Donald E.; Lin, Chung-Ho; McElroy, Jane A.; Nagel, Susan C.

    2016-01-01

    Background: Hydraulic fracturing technologies, developed over the last 65 years, have only recently been combined with horizontal drilling to unlock oil and gas reserves previously deemed inaccessible. While these technologies have dramatically increased domestic oil and natural gas production, they have also raised concerns for the potential contamination of local water supplies with the approximately 1,000 chemicals used throughout the process, including many known or suspected endocrine-disrupting chemicals.Objectives: We discuss the need for an endocrine component to health assessments for drilling-dense regions in the context of hormonal and anti-hormonal activities for chemicals used.Methods: We discuss the literature on 1) surface and ground water contamination by oil and gas extraction operations, and 2) potential human exposure, particularly in context of the total hormonal and anti-hormonal activities present in surface and ground water from natural and anthropogenic sources, with initial analytical results and critical knowledge gaps discussed.Discussion: In light of the potential for environmental release of oil and gas chemicals that can disrupt hormone receptor systems, we recommend methods for assessing complex hormonally active environmental mixtures.Conclusions: We describe a need for an endocrine-centric component for overall health assessments and provide supporting information that using this may help explain reported adverse health trends as well as help develop recommendations for environmental impact assessments and monitoring programs.

  6. Critical analysis of the data on complexation of lanthanides and actinides by natural organic matter: particular case of humic substances

    International Nuclear Information System (INIS)

    Reiller, P.

    2010-01-01

    This document proposes a critical analysis of the models that describe the actinides and lanthanides complexation by natural organic matter in general and by humic substances in particular. In order to better delimit the particular properties of these substances the most influent physical and chemical properties on complexation are recalled as a preamble. Models as well as data that has been used are reviewed, compiled, and eventually compared to independent data in order to identify (i) their application domain, (ii) the possible simplifications which permit to obtain operational models, (iii) the conditions in which simplifications cannot be ascertained yet, and (iv) the data or fields of knowledge which are still too uncertain. A comparison between the different models is proposed in order to adapt parameters from one model to another minimising the experimental acquisitions, or at least to focus on missing data. Usually, data on the complexation of free ions M z+ are reliable; as soon as hydrolysis, or competition with another ligand in general, in at stake data are much less reliable. Predictions from models are much more uncertain: formation of mixed complexes with hydroxide or carbonate anions is not univocal whatever the modelling strategy. Hints for transfer functions between models which are believed to be incompatible could be explored in order to justify necessary simplifications for using operational modelling. Influence on the solubility of oxides could be quantified, but it is difficult to clearly separate it from colloidal particles stabilisation. The account of the competition between cations by the models has also been tested. In view of the small number of available experimental data there still lie some uncertainties especially for the media that are close to neutrality and in the case of competition with magnesium, but overall in the case of the competition with aluminium and iron. The influence of redox activity of humic substances is also

  7. Experimental investigation of aluminum complexing with sodium ion and of gallium and iron (III) speciation in natural solutions

    International Nuclear Information System (INIS)

    Diakonov, Igor

    1995-01-01

    The aim of this work is to acquire thermodynamic data on the aqueous complexes forming between sodium and aluminum, gallium and hydroxide, and iron (III) and hydroxide. These data will provide for a better understanding of the transport and distribution of these elements in surface and hydrothermal fluids. Stability constants of the sodium-aluminate complex (Na Al(OH) 4 deg.) were obtained from boehmite solubility measurements at temperatures from 125 to 350 deg. C in alkaline solutions containing from 0.1 to 1 mol/L sodium. Complementary potentiometric measurements were performed with a sodium selective electrode, between 75 and 200 deg C (the potentiometric study was carried out by Gleb Pokrovski). Analyses of these data within the framework of the revised Helgeson-Kirkham-Flowers (HKF) model allowed determination of the HKF parameters for Na Al(OH) 4 deg. and calculation of its thermodynamic properties to 800 deg. C and 5 kb. The results of this work show that Na Al(OH) 4 deg. complex formation increases significantly the solubility of aluminum-bearing minerals and consequently aluminum mobility in hydrothermal fluids. Gallium speciation in surface and hydrothermal fluids is dominated by the negatively charged species, Ga(OH) 4 - . The thermodynamic properties of this species were determined from of OEGaOOH solubility measurements as a function of pH and temperature from 25 to 250 deg. C. In general, the variation of gallium aqueous speciation with pH is similar to that of aluminum other than at temperatures less than 200 deg. C over the pH range 3 - 6. This difference can account for the independent behavior of gallium versus aluminum in numerous low temperature natural systems. The thermodynamic properties of Fe(OH) 3 deg. which dominates the speciation of Fe(III) in surface waters and Fe(OH) 4 - were determined from hematite solubility measurements as a function of pH, oxygen pressure and temperature from 110 to 300 deg. C. The available thermodynamic data on

  8. Coral reefs in an urban embayment in Hawaii: a complex case history controlled by natural and anthropogenic stress

    Science.gov (United States)

    Grigg, R. W.

    1995-11-01

    The effects of natural and anthropogenic stress need to be separated before coral reef ecosystems can be effectively managed. In this paper, a 25 year case history of coral reefs in an urban embayment (Mamala Bay) off Honolulu, Hawaii is described and differences between natural and man-induced stress are distinguished. Mamala Bay is a 30 km long shallow coastal bay bordering the southern (leeward) shore of Oahu and the city of Honolulu in the Hawaiian Islands. During the last 25 years, this area has been hit by two magnitude 5 hurricane events (winds > 240 km/h) generating waves in excess of 7.5 m. Also during this period, two large sewer outfalls have discharged up to 90 million gallons per day (mgd) or (360 × 106 L/day) of point source pollution into the bay. Initially the discharge was raw sewage, but since 1977 it has received advanced primary treatment. Non-point source run-off from the Honolulu watershed also enters the bay on a daily basis. The results of the study show that discharge of raw sewage had a serious but highly localized impact on shallow (˜10 m) reef corals in the bay prior to 1977. After 1977, when treatment was upgraded to the advanced primary level and outfalls were extended to deep water (> 65 m), impacts to reef corals were no longer significant. No measurable effects of either point or non-point source pollution on coral calcification, growth, species composition, diversity or community structure related to pollution can now be detected. Conversely the effects of hurricane waves in 1982 and 1992 together caused major physical destruction to the reefs. In 1982, average coral cover of well-developed offshore reefs dropped from 60-75% to 5-15%. Only massive species in high relief areas survived. Today, recovery is occurring, and notwithstanding major future disturbance events, long-term biological processes should eventually return the coral ecosystems to a more mature successional stage. This case history illustrates the complex nature of

  9. Investigating NARCCAP Precipitation Extremes via Bivariate Extreme Value Theory (Invited)

    Science.gov (United States)

    Weller, G. B.; Cooley, D. S.; Sain, S. R.; Bukovsky, M. S.; Mearns, L. O.

    2013-12-01

    We introduce methodology from statistical extreme value theory to examine the ability of reanalysis-drive regional climate models to simulate past daily precipitation extremes. Going beyond a comparison of summary statistics such as 20-year return values, we study whether the most extreme precipitation events produced by climate model simulations exhibit correspondence to the most extreme events seen in observational records. The extent of this correspondence is formulated via the statistical concept of tail dependence. We examine several case studies of extreme precipitation events simulated by the six models of the North American Regional Climate Change Assessment Program (NARCCAP) driven by NCEP reanalysis. It is found that the NARCCAP models generally reproduce daily winter precipitation extremes along the Pacific coast quite well; in contrast, simulation of past daily summer precipitation extremes in a central US region is poor. Some differences in the strength of extremal correspondence are seen in the central region between models which employ spectral nudging and those which do not. We demonstrate how these techniques may be used to draw a link between extreme precipitation events and large-scale atmospheric drivers, as well as to downscale extreme precipitation simulated by a future run of a regional climate model. Specifically, we examine potential future changes in the nature of extreme precipitation along the Pacific coast produced by the pineapple express (PE) phenomenon. A link between extreme precipitation events and a "PE Index" derived from North Pacific sea-surface pressure fields is found. This link is used to study PE-influenced extreme precipitation produced by a future-scenario climate model run.

  10. Effects of extreme natural events on the provision of ecosystem services in a mountain environment: The importance of trail design in delivering system resilience and ecosystem service co-benefits.

    Science.gov (United States)

    Tomczyk, Aleksandra M; White, Piran C L; Ewertowski, Marek W

    2016-01-15

    A continued supply of ecosystem services (ES) from a system depends on the resilience of that system to withstand shocks and perturbations. In many parts of the world, climate change is leading to an increased frequency of extreme weather events, potentially influencing ES provision. Our study of the effects of an intense rainfall event in Gorce National Park, Poland, shows: (1) the intense rainfall event impacted heavily on the supply of ES by limiting potential recreation opportunities and reducing erosion prevention; (2) these negative impacts were not only restricted to the period of the extreme event but persisted for up to several years, depending on the pre-event trail conditions and post-event management activities; (3) to restore the pre-event supply of ES, economic investments were required in the form of active repairs to trails, which, in Gorce National Park, were an order of magnitude higher than the costs of normal trail maintenance; and (4) when recreational trails were left to natural restoration, loss of biodiversity was observed, and recovery rates of ES (recreation opportunities and soil erosion prevention) were reduced in comparison to their pre-event state. We conclude that proper trail design and construction provides a good solution to avoid some of the negative impacts of extreme events on recreation, as well as offering co-benefits in terms of protecting biodiversity and enhancing the supply of regulating services such as erosion prevention. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Supramolecular Architectures and Mimics of Complex Natural Folds Derived from Rationally Designed alpha-Helical Protein Structures

    Science.gov (United States)

    Tavenor, Nathan Albert

    Protein-based supramolecular polymers (SMPs) are a class of biomaterials which draw inspiration from and expand upon the many examples of complex protein quaternary structures observed in nature: collagen, microtubules, viral capsids, etc. Designing synthetic supramolecular protein scaffolds both increases our understanding of natural superstructures and allows for the creation of novel materials. Similar to small-molecule SMPs, protein-based SMPs form due to self-assembly driven by intermolecular interactions between monomers, and monomer structure determines the properties of the overall material. Using protein-based monomers takes advantage of the self-assembly and highly specific molecular recognition properties encodable in polypeptide sequences to rationally design SMP architectures. The central hypothesis underlying our work is that alpha-helical coiled coils, a well-studied protein quaternary folding motif, are well-suited to SMP design through the addition of synthetic linkers at solvent-exposed sites. Through small changes in the structures of the cross-links and/or peptide sequence, we have been able to control both the nanoscale organization and the macroscopic properties of the SMPs. Changes to the linker and hydrophobic core of the peptide can be used to control polymer rigidity, stability, and dimensionality. The gaps in knowledge that this thesis sought to fill on this project were 1) the relationship between the molecular structure of the cross-linked polypeptides and the macroscopic properties of the SMPs and 2) a means of creating materials exhibiting multi-dimensional net or framework topologies. Separate from the above efforts on supramolecular architectures was work on improving backbone modification strategies for an alpha-helix in the context of a complex protein tertiary fold. Earlier work in our lab had successfully incorporated unnatural building blocks into every major secondary structure (beta-sheet, alpha-helix, loops and beta

  12. A Comparative Study on Recently-Introduced Nature-Based Global Optimization Methods in Complex Mechanical System Design

    Directory of Open Access Journals (Sweden)

    Abdulbaset El Hadi Saad

    2017-10-01

    Full Text Available Advanced global optimization algorithms have been continuously introduced and improved to solve various complex design optimization problems for which the objective and constraint functions can only be evaluated through computation intensive numerical analyses or simulations with a large number of design variables. The often implicit, multimodal, and ill-shaped objective and constraint functions in high-dimensional and “black-box” forms demand the search to be carried out using low number of function evaluations with high search efficiency and good robustness. This work investigates the performance of six recently introduced, nature-inspired global optimization methods: Artificial Bee Colony (ABC, Firefly Algorithm (FFA, Cuckoo Search (CS, Bat Algorithm (BA, Flower Pollination Algorithm (FPA and Grey Wolf Optimizer (GWO. These approaches are compared in terms of search efficiency and robustness in solving a set of representative benchmark problems in smooth-unimodal, non-smooth unimodal, smooth multimodal, and non-smooth multimodal function forms. In addition, four classic engineering optimization examples and a real-life complex mechanical system design optimization problem, floating offshore wind turbines design optimization, are used as additional test cases representing computationally-expensive black-box global optimization problems. Results from this comparative study show that the ability of these global optimization methods to obtain a good solution diminishes as the dimension of the problem, or number of design variables increases. Although none of these methods is universally capable, the study finds that GWO and ABC are more efficient on average than the other four in obtaining high quality solutions efficiently and consistently, solving 86% and 80% of the tested benchmark problems, respectively. The research contributes to future improvements of global optimization methods.

  13. Deciphering Transcriptome and Complex Alternative Splicing Transcripts in Mammary Gland Tissues from Cows Naturally Infected with Staphylococcus aureus Mastitis

    Science.gov (United States)

    Jiang, Qiang; Yang, Chun Hong; Zhang, Yan; Sun, Yan; Li, Rong Ling; Wang, Chang Fa; Zhong, Ji Feng; Huang, Jin Ming

    2016-01-01

    Alternative splicing (AS) contributes to the complexity of the mammalian proteome and plays an important role in diseases, including infectious diseases. The differential AS patterns of these transcript sequences between the healthy (HS3A) and mastitic (HS8A) cows naturally infected by Staphylococcus aureus were compared to understand the molecular mechanisms underlying mastitis resistance and susceptibility. In this study, using the Illumina paired-end RNA sequencing method, 1352 differentially expressed genes (DEGs) with higher than twofold changes were found in the HS3A and HS8A mammary gland tissues. Gene ontology and KEGG pathway analyses revealed that the cytokine–cytokine receptor interaction pathway is the most significantly enriched pathway. Approximately 16k annotated unigenes were respectively identified in two libraries, based on the bovine Bos taurus UMD3.1 sequence assembly and search. A total of 52.62% and 51.24% annotated unigenes were alternatively spliced in term of exon skipping, intron retention, alternative 5′ splicing and alternative 3ʹ splicing. Additionally, 1,317 AS unigenes were HS3A-specific, whereas 1,093 AS unigenes were HS8A-specific. Some immune-related genes, such as ITGB6, MYD88, ADA, ACKR1, and TNFRSF1B, and their potential relationships with mastitis were highlighted. From Chromosome 2, 4, 6, 7, 10, 13, 14, 17, and 20, 3.66% (HS3A) and 5.4% (HS8A) novel transcripts, which harbor known quantitative trait locus associated with clinical mastitis, were identified. Many DEGs in the healthy and mastitic mammary glands are involved in immune, defense, and inflammation responses. These DEGs, which exhibit diverse and specific splicing patterns and events, can endow dairy cattle with the potential complex genetic resistance against mastitis. PMID:27459697

  14. Assessment of natural radium isotopes and 222Rn in water samples from Cananeia-Iguape estuarine complex, Sao Paulo, Brazil

    International Nuclear Information System (INIS)

    Oliveira, Joselene de; Jesus, Sueli Carvalho de; Abrahao, Fernanda Franco; Santos, Glorivania Ferreira dos; Braga, Elisabete de Santis; Chiozzini, Vitor

    2009-01-01

    Radium isotopes and radon are among the most important natural radionuclides in the environment from both radioprotection and geo-hydrological points of view. These radionuclides are a powerful tool for studying coastal processes and have been used intensively as tracers of groundwater sources that discharge into the ocean. In this paper, naturally occurring radium isotopes and 222 Rn were determined to trace water exchange and SGD in Cananeia-Iguape estuarine complex, a shallow coastal plain estuary in southern Sao Paulo area. The research work was carried out during the first semester of 2009 and covered stations located both in Cananeia and Iguape outlets, as well as samples collected in Ribeira of Iguape River and groundwater. Activity concentrations of 226 Ra in estuarine waters from Cananeia outlet varied from 2.9 mBq L -1 to 4.7 mBq L -1 , while 228 Ra concentrations ranged from 22 mBq L -1 to 45 mBq L -1 . In Iguape outlet, activities of 226 Ra ranged from 1.6 mBq L -1 to 6.6 mBq L -1 ; 228 Ra varied from 13 mBq L -1 to 20 mBq L -1 . Activities of Ra were slightly higher in samples collected at 5 m depth than at the surface water level. Groundwater activity concentrations of 226 Ra ranged from 0.63 mBq L -1 to 12 mBq L -1 and for 228 Ra from 18 mBq L -1 to 39 mBq L -1 . In groundwater, the 228 Ra/ 226 Ra activity ratios varied from 3.3 to 31.7. 222 Rn activities in groundwater up to 747 Bq L -1 were observed. Increased nitrate contents were observed in groundwater samples collected in Cananeia and Comprida Island. (author)

  15. Role of major histocompatibility complex class II in resistance of mice to naturally acquired infection with Syphacia obvelata

    Science.gov (United States)

    Stewart, Patricia W.; Chapes, Stephen K.

    2003-01-01

    Genetics plays a substantial role in host resistance in many host-parasite interactions. We examined the prevalence of naturally acquired infection with Syphacia obvelata in a number of mouse strains housed in a non-barrier facility. These mice, which included cross-bred and congenic, inbred strains on various genetic backgrounds, differ in the loci for the immune function genes--major histocompatibility complex class II (MHCII), toll-like receptor 4 (Tlr4), and solute carrier family 11, member 1 (Slc11a1)--which allowed comparisons of the impact of these genes on resistance to pinworm infection. Male and female mice of various ages were sampled over an 18-month period; infection was determined by use of the cellophane tape test. Results indicated that mice that were MHCII+/+ had a significantly lower prevalence of infection than did mice that were MHCII-/-. Differences were not seen between male and female mice. Although MHCII+/+ mice had an age-associated decrease in infection prevalence, such decrease was not seen in MHCII-/- mice. In contrast, infection prevalence in mice with the normal Tlr4 gene (Tlr4(LPS-n/LPS-n)) gene did not differ significantly compared with that in mice that were homozygous for either the point mutation (Tlr4(LPS-d/LPS-d)) or deletion (Tlr4(LPS-del/LPS-del)) of that gene. Likewise, the presence (Sle11a1r/r) or absence (Slc11a1s/s) of functional alleles for Slc11a1 had no effect on the prevalence of infection with S. obvelata. In conclusion, presence of MHCII, but not Tlr4 or Slc11a1 significantly influences prevalence of naturally acquired infection with S. obvelata. These data justify further comprehensive analyses of the immune components that are involved in pinworm resistance.

  16. Modified Graded Motor Imagery for Complex Regional Pain Syndrome Type 1 of the Upper Extremity in the Acute Phase: A Patient Series

    Science.gov (United States)

    Lagueux, Emilie; Charest, Joelle; Lefrancois-Caron, Eve; Mauger, Marie-Eve; Mercier, Emilie; Savard, Kim; Tousignant-Laflamme, Yannick

    2012-01-01

    Complex regional pain syndrome (CRPS) is a pathologic condition in which the painful experience is disproportionate in time and intensity in comparison with the inciting event. At present, the pathophysiology of CRPS is not well understood. Several studies have indicated that cortical reorganization plays a role in the persistence of the symptoms.…

  17. Behavioral Repertoire Influences the Rate and Nature of Learning in Climbing: Implications for Individualized Learning Design in Preparation for Extreme Sports Participation

    Directory of Open Access Journals (Sweden)

    Dominic Orth

    2018-06-01

    Full Text Available Extreme climbing where participants perform while knowing that a simple mistake could result in death requires a skill set normally acquired in non-extreme environments. In the ecological dynamics approach to perception and action, skill acquisition involves a process where the existing repertoire of behavioral capabilities (or coordination repertoire of a learner are destabilized and re-organized through practice—this process can expand the individuals affordance boundaries allowing the individual to explore new environments. Change in coordination repertoire has been observed in bi-manual coordination and postural regulation tasks, where individuals begin practice using one mode of coordination before transitioning to another, more effective, coordination mode during practice. However, individuals may also improve through practice without qualitatively reorganizing movement system components—they do not find a new mode of coordination. To explain these individual differences during learning (i.e., whether or not a new action is discovered, a key candidate is the existing coordination repertoire present prior to practice. In this study, the learning dynamics of body configuration patterns organized with respect to an indoor climbing surface were observed and the existing repertoire of coordination evaluated prior to and after practice. Specifically, performance outcomes and movement patterns of eight beginners were observed across 42 trials of practice over a 7-week period. A pre- and post-test scanning procedure was used to determine existing patterns of movement coordination and the emergence of new movement patterns after the practice period. Data suggested the presence of different learning dynamics by examining trial-to-trial performance in terms of jerk (an indicator of climbing fluency, at the individual level of analysis. The different learning dynamics (identified qualitatively included: continuous improvement, sudden improvement

  18. Laboratory survival and blood feeding response of wild-caught Culicoides obsoletus Complex (Diptera: Ceratopogonidae) through natural and artificial membranes.

    Science.gov (United States)

    Goffredo, M; Romeo, G; Monaco, F; Di Gennaro, A; Savini, G

    2004-01-01

    In late summer 2002, live wild-caught midges of the Obsoletus Complex were collected using blacklight traps placed at a horse stable in Teramo (Abruzzo, Italy). For the survival study under laboratory conditions, 1,500 Obsoletus Complex midges were kept at 17 degrees C-25 degrees C and provided only with a sucrose solution. Of these, 150 (10%) survived for at least 40 days and 3 midges were still alive after 92 days. In addition, 10 midges survived 10 days at 4 degrees C. For the feeding trials, 40 blood-meals (9,440 midges) were administered, 27 of which were successful (67.5%); the feeding rate ranged from 0.3% to 16.7%, with a total of 592 engorged midges. Similar feeding rates (U Mann-Whitney test=129.5 p>0.05) were obtained when natural (day-old chicken skin) and artificial (stretched parafilm) membranes were used. To infect the insects, a field strain of bluetongue (BT) virus (BTV) serotype 2 isolated from the spleen of a sheep during the 2000 Italian outbreak was added to the blood-meal. Two different viral solutions, with titres of 10(6)TCID(50)/ml and 10(7)TCID(50)/ml, were prepared. Uninfected blood was significantly more appetising (U Mann-Whitney test=88.5 pdays. During the incubation period, the dead insects were collected daily and analysed for evidence of virus infection. Of the 251 engorged midges, 54 (21.5%) died in the feeding chambers or during sorting on the chill table, 136 died within the first 10 days and 61 survived longer. BTV was isolated only from those which died just after feeding (52.6%; 10/19) or 24 h later (47.8%; 11/23). Considering the small number of midges tested after 10 days of incubation, the prevalence of infection detected in this study (95% probability) would have been higher than 4.74%. These preliminary results appear very promising as this is the first time that midges of the Obsoletus Complex have been successfully fed under laboratory conditions.

  19. Complexity explained

    CERN Document Server

    Erdi, Peter

    2008-01-01

    This book explains why complex systems research is important in understanding the structure, function and dynamics of complex natural and social phenomena. Readers will learn the basic concepts and methods of complex system research.

  20. Watershed System Model: The Essentials to Model Complex Human-Nature System at the River Basin Scale

    Science.gov (United States)

    Li, Xin; Cheng, Guodong; Lin, Hui; Cai, Ximing; Fang, Miao; Ge, Yingchun; Hu, Xiaoli; Chen, Min; Li, Weiyue

    2018-03-01

    Watershed system models are urgently needed to understand complex watershed systems and to support integrated river basin management. Early watershed modeling efforts focused on the representation of hydrologic processes, while the next-generation watershed models should represent the coevolution of the water-land-air-plant-human nexus in a watershed and provide capability of decision-making support. We propose a new modeling framework and discuss the know-how approach to incorporate emerging knowledge into integrated models through data exchange interfaces. We argue that the modeling environment is a useful tool to enable effective model integration, as well as create domain-specific models of river basin systems. The grand challenges in developing next-generation watershed system models include but are not limited to providing an overarching framework for linking natural and social sciences, building a scientifically based decision support system, quantifying and controlling uncertainties, and taking advantage of new technologies and new findings in the various disciplines of watershed science. The eventual goal is to build transdisciplinary, scientifically sound, and scale-explicit watershed system models that are to be codesigned by multidisciplinary communities.

  1. An engineered genetic selection for ternary protein complexes inspired by a natural three-component hitchhiker mechanism.

    Science.gov (United States)

    Lee, Hyeon-Cheol; Portnoff, Alyse D; Rocco, Mark A; DeLisa, Matthew P

    2014-12-22

    The bacterial twin-arginine translocation (Tat) pathway is well known to translocate correctly folded monomeric and dimeric proteins across the tightly sealed cytoplasmic membrane. We identified a naturally occurring heterotrimer, the Escherichia coli aldehyde oxidoreductase PaoABC, that is co-translocated by the Tat translocase according to a ternary "hitchhiker" mechanism. Specifically, the PaoB and PaoC subunits, each devoid of export signals, are escorted to the periplasm in a piggyback fashion by the Tat signal peptide-containing subunit PaoA. Moreover, export of PaoA was blocked when either PaoB or PaoC was absent, revealing a surprising interdependence for export that is not seen for classical secretory proteins. Inspired by this observation, we created a bacterial three-hybrid selection system that links the formation of ternary protein complexes with antibiotic resistance. As proof-of-concept, a bispecific antibody was employed as an adaptor that physically crosslinked one antigen fused to a Tat export signal with a second antigen fused to TEM-1 β-lactamase (Bla). The resulting non-covalent heterotrimer was exported in a Tat-dependent manner, delivering Bla to the periplasm where it hydrolyzed β-lactam antibiotics. Collectively, these results highlight the remarkable flexibility of the Tat system and its potential for studying and engineering ternary protein interactions in living bacteria.

  2. An adaptive network-based fuzzy inference system for short-term natural gas demand estimation: Uncertain and complex environments

    International Nuclear Information System (INIS)

    Azadeh, A.; Asadzadeh, S.M.; Ghanbari, A.

    2010-01-01

    Accurate short-term natural gas (NG) demand estimation and forecasting is vital for policy and decision-making process in energy sector. Moreover, conventional methods may not provide accurate results. This paper presents an adaptive network-based fuzzy inference system (ANFIS) for estimation of NG demand. Standard input variables are used which are day of the week, demand of the same day in previous year, demand of a day before and demand of 2 days before. The proposed ANFIS approach is equipped with pre-processing and post-processing concepts. Moreover, input data are pre-processed (scaled) and finally output data are post-processed (returned to its original scale). The superiority and applicability of the ANFIS approach is shown for Iranian NG consumption from 22/12/2007 to 30/6/2008. Results show that ANFIS provides more accurate results than artificial neural network (ANN) and conventional time series approach. The results of this study provide policy makers with an appropriate tool to make more accurate predictions on future short-term NG demand. This is because the proposed approach is capable of handling non-linearity, complexity as well as uncertainty that may exist in actual data sets due to erratic responses and measurement errors.

  3. An extremely bulky tris(pyrazolyl)methanide: a tridentate ligand for the synthesis of heteroleptic magnesium(II) and ytterbium(II) alkyl, hydride, and iodide complexes.

    Science.gov (United States)

    Lalrempuia, Ralte; Stasch, Andreas; Jones, Cameron

    2015-02-01

    The tris(pyrazolyl)methane compound HC(3-Ad-5-Mepz)3 [1, 3-Ad-5-Mepz=3-(1-adamantyl)-5-methylpyrazolyl] and its regioisomer, HC(3-Ad-5-Mepz)2 (3-Me-5-Adpz), were synthesized and crystallographically characterized. Deprotonation of 1 with MeLi afforded the lithium complex [{κ(3) -N-C(3-Ad-5-Mepz)3 }Li(thf)], which incorporates a tris(pyrazolyl)methanide ligand of unprecedented bulk. Reaction of 1 with MeMgI gave the ionic coordination complex [{κ(3) -N-HC(3-Ad-5-Mepz)3 }MgMe]I, which was readily deprotonated to afford the neutral compound [{κ(3) -N-C(3-Ad-5-Mepz)3 }MgMe]. The related magnesium butyl compound [{κ(3) -N-C(3-Ad-5-Mepz)3 }MgBu] was prepared from the reaction of 1 and MgBu2 . Treating this with LiAlH4 or LiAlD4 led to rare examples of terminal magnesium hydride/deuteride complexes, [{κ(3) -N-C(3-Ad-5-Mepz)3 }MgH/D]. All neutral magnesium alkyl and hydride compounds were crystallographically authenticated. Reaction of [{κ(3) κN-C(3-Ad-5-Mepz)3 }Li(thf)] with [YbI2 (thf)2 ] yielded the first structurally characterized f-block tris(pyrazolyl)methanide complex, [{κ(3) -N-C(3-Ad-5-Mepz)3 }YbI(thf)]. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Binding of hydrocarbons and other extremely weak ligands to transition metal complexes that coordinate hydrogen: Investigation of cis-interactions and delocalized bonding involving sigma bonds

    International Nuclear Information System (INIS)

    Kubas, G.J.; Eckert, J.; Luo, X.L.

    1997-01-01

    This is the final report of a three-year Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). At the forefront of chemistry are efforts to catalytically transform the inert C-H bonds in alkanes to more useful products using metal compounds. The goal is to observe binding and cleavage of alkane C-H bonds on metals or to use related silane Si-H bonding as models, analogous to the discovery of hydrogen (H 2 ) binding to metals. Studies of these unique sigma complexes (M hor-ellipsis H-Y; Y double-bond H, Si, C) will aid in developing new catalysts or technologies relevant to DOE interest, e.g., new methods for tritium isotope separation. Several transition metals (Mo, W, Mn, and Pt) were found to reversibly bind and cleave H 2 , silanes, and halocarbons. The first metal-SiH 4 complexes, thus serving as a model for methane reactions. A second goal is to study the dynamics and energetics of H-Y bonds on metals by neutron scattering, and evidence for interactions between bound H-Y and nearby H atoms on metal complexes has been found

  5. Learning from Nature - Mapping of Complex Hydrological and Geomorphological Process Systems for More Realistic Modelling of Hazard-related Maps

    Science.gov (United States)

    Chifflard, Peter; Tilch, Nils

    2010-05-01

    Introduction Hydrological or geomorphological processes in nature are often very diverse and complex. This is partly due to the regional characteristics which vary over time and space, as well as changeable process-initiating and -controlling factors. Despite being aware of this complexity, such aspects are usually neglected in the modelling of hazard-related maps due to several reasons. But particularly when it comes to creating more realistic maps, this would be an essential component to consider. The first important step towards solving this problem would be to collect data relating to regional conditions which vary over time and geographical location, along with indicators of complex processes. Data should be acquired promptly during and after events, and subsequently digitally combined and analysed. Study area In June 2009, considerable damage occurred in the residential area of Klingfurth (Lower Austria) as a result of great pre-event wetness and repeatedly heavy rainfall, leading to flooding, debris flow deposit and gravitational mass movement. One of the causes is the fact that the meso-scale watershed (16 km²) of the Klingfurth stream is characterised by adverse geological and hydrological conditions. Additionally, the river system network with its discharge concentration within the residential zone contributes considerably to flooding, particularly during excessive rainfall across the entire region, as the flood peaks from different parts of the catchment area are superposed. First results of mapping Hydro(geo)logical surveys across the entire catchment area have shown that - over 600 gravitational mass movements of various type and stage have occurred. 516 of those have acted as a bed load source, while 325 mass movements had not reached the final stage yet and could thus supply bed load in the future. It should be noted that large mass movements in the initial or intermediate stage were predominately found in clayey-silty areas and weathered material

  6. Assessment of multiple sources of anthropogenic and natural chemical inputs to a morphologically complex basin, Lake Mead, USA

    Science.gov (United States)

    Rosen, Michael R.; Van Metre, P.C.

    2010-01-01

    Lakes with complex morphologies and with different geologic and land-use characteristics in their sub-watersheds could have large differences in natural and anthropogenic chemical inputs to sub-basins in the lake. Lake Mead in southern Nevada and northern Arizona, USA, is one such lake. To assess variations in chemical histories from 1935 to 1998 for major sub-basins of Lake Mead, four sediment cores were taken from three different parts of the reservoir (two from Las Vegas Bay and one from the Overton Arm and Virgin Basin) and analyzed for major and trace elements, radionuclides, and organic compounds. As expected, anthropogenic contaminant inputs are greatest to Las Vegas Bay reflecting inputs from the Las Vegas urban area, although concentrations are low compared to sediment quality guidelines and to other USA lakes. One exception to this pattern was higher Hg in the Virgin Basin core. The Virgin Basin core is located in the main body of the lake (Colorado River channel) and is influenced by the hydrology of the Colorado River, which changed greatly with completion of Glen Canyon Dam upstream in 1963. Major and trace elements in the core show pronounced shifts in the early 1960s and, in many cases, gradually return to concentrations more typical of pre-1960s by the 1980s and 1990s, after the filling of Lake Powell. The Overton Arm is the sub-basin least effected by anthropogenic contaminant inputs but has a complex 137Cs profile with a series of large peaks and valleys over the middle of the core, possibly reflecting fallout from nuclear tests in the 1950s at the Nevada Test Site. The 137Cs profile suggests a much greater sedimentation rate during testing which we hypothesize results from greatly increased dust fall on the lake and Virgin and Muddy River watersheds. The severe drought in the southwestern USA during the 1950s might also have played a role in variations in sedimentation rate in all of the cores. ?? 2009.

  7. Study of natural biota of and biologic recovery possibilities for closed tunnels of the Degelen mountain complex

    International Nuclear Information System (INIS)

    Tuleubaev, B.A.; Baiganov, A.T.; Seisebaev, A.T.; Nesipbaev, Sh.T.; Dzhanin, B.T.; Sultanova, B.M.

    1998-01-01

    Processes of degradation due to nuclear testing affected all the components of the ecosystems stems of the Degelen Mountain Complex. The composition of the vegetative cover of the Degelen Mountains distinguishes by the diversity of vegetation due to significant differentiation of ecological conditions of vegetation growth. Here the following types of vegetation are present: steppe, meadow, forest, bushes, and desert. The peculiarity of vegetation is the presence of large forest areas (containing birch, aspen-birch, and poplar-aspen areas) in narrow mountain valleys and the certain locations of the main fragments of forests typical for them. In accordance with the methodology of the vertical zoning, the following zones have been determined on the territory of the Degelen Mountains: 1) a zone of mountainous meadow and motley-feather steppe; 2) a zone of bushes. During the field work of the Inst. of Radiation Safety and Ecology (IRSE) on analysis of Degelen Mountains' flora 387 species of vascular plants of 58 families have been found. This data permits to characterize the structure and the patterns of the specific flora on the representative area of the Degelen Mountains on the southeast edge of the Central Kazakstan Low Hills. The assessment of flora taxonomic diversity, the quantitative set of species and families reflects the specific properties inherent in flora of the Degelen Mountains of the east edge of the Central Kazakstan Low Hills. The floristic composition of the Degelen Mountain Complex is more rich as compared to that one of the other two test fields of the former STS: Experimental Field - 148 species, Balapan - 192 species. Data of ecological, geological and butanic studies allowed to determine the main types of anthropogenic destruction of the ecosystem and the nature of their spatial distribution, the major cenosis-forming species for every type of anthropogenic residence and the radioecological growth amplitude of the dominant cenosis

  8. Extreme negotiations.

    Science.gov (United States)

    Weiss, Jeff; Donigian, Aram; Hughes, Jonathan

    2010-11-01

    CEOs and other senior executives must make countless complex, high-stakes deals across functional areas and divisions, with alliance partners and critical suppliers, and with customers and regulators. The pressure of such negotiations may make them feel a lot like U.S. military officers in an Afghan village, fending off enemy fire while trying to win trust and get intelligence from the local populace. Both civilian and military leaders face what the authors call "dangerous negotiations," in which the traps are many and good advice is scarce. Although the sources of danger are quite different for executives and officers, they resort to the same kinds of behaviors. Both feel pressure to make quick progress, project strength and control (particularly when they have neither), rely on force rather than collaboration, trade resources for cooperation rather than build trust, and make unwanted compromises to minimize potential damage. The authors outline five core strategies that "in extremis" military negotiators use to resolve conflicts and influence others: maintaining a big-picture perspective; uncovering hidden agendas to improve collaboration; using facts and fairness to get buy-in; building trust; and focusing on process as well as outcomes. These strategies provide an effective framework that business executives can use to prepare for a negotiation and guide their moves at the bargaining table.

  9. Humic substances in natural waters and their complexation with trace metals and radionuclides: a review. [129 references

    Energy Technology Data Exchange (ETDEWEB)

    Boggs, S. Jr.; Livermore, D.; Seitz, M.G.

    1985-07-01

    Dissolved humic substances (humic and fulvic acids) occur in surface waters and groundwaters in concentrations ranging from less than 1 mg(C)/L to more than 100 mg(C)/L. Humic substances are strong complexing agents for many trace metals in the environment and are also capable of forming stable soluble complexes or chelates with radionuclides. Concentrations of humic materials as low as 1 mg(C)/L can produce a detectable increase in the mobility of some actinide elements by forming soluble complexes that inhibit sorption of the radionuclides onto rock materials. The stability of trace metal- or radionuclide-organic complexes is commonly measured by an empirically determined conditional stability constant (K'), which is based on the ratio of complexed metal (radionuclide) in solution to the product concentration of uncomplexed metal and humic complexant. Larger values of stability constants indicate greater complex stability. The stability of radionuclide-organic complexes is affected both by concentration variables and envionmental factors. In general, complexing is favored by increased of radionuclide, increased pH, and decreased ionic strength. Actinide elements are generally most soluble in their higher oxidation states. Radionuclides can also form stable, insoluble complexes with humic materials that tend to reduce radionuclide mobility. These insoluble complexes may be radionuclide-humate colloids that subsequently precipitate from solution, or complexes of radionuclides and humic substances that sorb to clay minerals or other soil particulates strongly enough to immobilize the radionuclides. Colloid formation appears to be favored by increased radionuclide concentration and lowered pH; however, the conditions that favor formation of insoluble complexes that sorb to particulates are still poorly understood. 129 refs., 25 figs., 19 tabs.

  10. Non-Stationary Dependence Structures for Spatial Extremes

    KAUST Repository

    Huser, Raphaël

    2016-03-03

    Max-stable processes are natural models for spatial extremes because they provide suitable asymptotic approximations to the distribution of maxima of random fields. In the recent past, several parametric families of stationary max-stable models have been developed, and fitted to various types of data. However, a recurrent problem is the modeling of non-stationarity. In this paper, we develop non-stationary max-stable dependence structures in which covariates can be easily incorporated. Inference is performed using pairwise likelihoods, and its performance is assessed by an extensive simulation study based on a non-stationary locally isotropic extremal t model. Evidence that unknown parameters are well estimated is provided, and estimation of spatial return level curves is discussed. The methodology is demonstrated with temperature maxima recorded over a complex topography. Models are shown to satisfactorily capture extremal dependence.

  11. TOSCA - first international registry to address knowledge gaps in the natural history and management of tuberous sclerosis complex.

    Science.gov (United States)

    Kingswood, John C; Bruzzi, Paolo; Curatolo, Paolo; de Vries, Petrus J; Fladrowski, Carla; Hertzberg, Christoph; Jansen, Anna C; Jozwiak, Sergiusz; Nabbout, Rima; Sauter, Matthias; Touraine, Renaud; O'Callaghan, Finbar; Zonnenberg, Bernard; Crippa, Stefania; Comis, Silvia; d'Augères, Guillaume Beaure; Belousova, Elena; Carter, Tom; Cottin, Vincent; Dahlin, Maria; Ferreira, José Carlos; Macaya, Alfons; Benedik, Mirjana Perkovic; Sander, Valentin; Youroukos, Sotirios; Castellana, Ramon; Ulker, Bulent; Feucht, Martha

    2014-11-26

    Tuberous sclerosis complex (TSC) is a rare, multisystem, genetic disorder with an estimated prevalence between 1/6800 and 1/15000. Although recent years have seen huge progress in understanding the pathophysiology and in the management of TSC, several questions remain unanswered. A disease registry could be an effective tool to gain more insights into TSC and thus help in the development of improved management strategies. TuberOus SClerosis registry to increase disease Awareness (TOSCA) is a multicentre, international disease registry to assess manifestations, interventions, and outcomes in patients with TSC. Patients of any age diagnosed with TSC, having a documented visit for TSC within the preceding 12 months, or newly diagnosed individuals are eligible. Objectives include mapping the course of TSC manifestations and their effects on prognosis, identifying patients with rare symptoms and co-morbidities, recording interventions and their outcomes, contributing to creation of an evidence-base for disease assessment and therapy, informing further research on TSC, and evaluating the quality of life of patients with TSC. The registry includes a 'core' section and subsections or 'petals'. The 'core' section is designed to record general information on patients' background collected at baseline and updated annually. Subsections will be developed over time to record additional data related to specific disease manifestations and will be updated annually. The registry aimed to enrol approximately 2000 patients from about 250 sites in 31 countries. The initial enrolment period was of 24 months. A follow-up observation period of up to 5 years is planned. A pre-planned administrative analysis of 'core' data from the first 100 patients was performed to evaluate the feasibility of the registry. Results showed a high degree of accuracy of the data collection procedure. Annual interim analyses are scheduled. Results of first interim analysis will be presented subsequent to

  12. Natural disease course and genotype-phenotype correlations in Complex I deficiency caused by nuclear gene defects

    DEFF Research Database (Denmark)

    Koene, S; Rodenburg, R J; van der Knaap, M S

    2012-01-01

    cases and 126 from literature) with mutations in nuclear genes encoding structural complex I proteins or those involved in its assembly. Complex I deficiency caused by a nuclear gene defect is usually a non-dysmorphic syndrome, characterized by severe multi-system organ involvement and a poor prognosis...

  13. Towards Understanding and Managing Sustainable Complex, Dynamic Environmental/Economic/Social Systems - The Evolving Role of the Natural Sciences

    Science.gov (United States)

    Historically the natural sciences have played a major role in informing environmental management decisions. However, review of landmark cases like Love Canal, NY and Times Beach, MO have shown that the value of natural science information in decision making can be overwhelmed by ...

  14. Modeling silviculture after natural disturbance to sustain biodiversity in the longleaf pine (Pinus palustris) ecosystem : balancing complexity and implementation

    Science.gov (United States)

    Brian J. Palik; Robert J. Mitchell; J. Kevin Hiers

    2002-01-01

    Modeling silviculture after natural disturbance to maintain biodiversity is a popular concept, yet its application remains elusive. We discuss difficulties inherent to this idea, and suggest approaches to facilitate implementation, using longleaf pine (Pinus palustris) as an example. Natural disturbance regimes are spatially and temporally variable. Variability...

  15. Synthesis and anticancer activity of silver(I)-N-heterocyclic carbene complexes derived from the natural xanthine products caffeine, theophylline and theobromine.

    Science.gov (United States)

    Mohamed, Heba A; Lake, Benjamin R M; Laing, Thomas; Phillips, Roger M; Willans, Charlotte E

    2015-04-28

    A new library of silver(I)-N-heterocyclic carbene complexes prepared from the natural products caffeine, theophylline and theobromine is reported. The complexes have been fully characterised using a combination of NMR spectroscopy, mass spectrometry, elemental analysis and X-ray diffraction analysis. Furthermore, the hydrophobicity of the complexes has been measured. The silver(I)-N-heterocyclic carbenes have been evaluated for their antiproliferative properties against a range of cancer cell lines of different histological types, and compared to cisplatin. The data shows different profiles of response when compared to cisplatin in the same panel of cells, indicating a different mechanism of action. Furthermore, it appears that the steric effect of the ligand and the hydrophobicity of the complex both play a role in the chemosensitivity of these compounds, with greater steric bulk and greater hydrophilicity delivering higher cytotoxicity.

  16. Models and Inference for Multivariate Spatial Extremes

    KAUST Repository

    Vettori, Sabrina

    2017-12-07

    The development of flexible and interpretable statistical methods is necessary in order to provide appropriate risk assessment measures for extreme events and natural disasters. In this thesis, we address this challenge by contributing to the developing research field of Extreme-Value Theory. We initially study the performance of existing parametric and non-parametric estimators of extremal dependence for multivariate maxima. As the dimensionality increases, non-parametric estimators are more flexible than parametric methods but present some loss in efficiency that we quantify under various scenarios. We introduce a statistical tool which imposes the required shape constraints on non-parametric estimators in high dimensions, significantly improving their performance. Furthermore, by embedding the tree-based max-stable nested logistic distribution in the Bayesian framework, we develop a statistical algorithm that identifies the most likely tree structures representing the data\\'s extremal dependence using the reversible jump Monte Carlo Markov Chain method. A mixture of these trees is then used for uncertainty assessment in prediction through Bayesian model averaging. The computational complexity of full likelihood inference is significantly decreased by deriving a recursive formula for the nested logistic model likelihood. The algorithm performance is verified through simulation experiments which also compare different likelihood procedures. Finally, we extend the nested logistic representation to the spatial framework in order to jointly model multivariate variables collected across a spatial region. This situation emerges often in environmental applications but is not often considered in the current literature. Simulation experiments show that the new class of multivariate max-stable processes is able to detect both the cross and inner spatial dependence of a number of extreme variables at a relatively low computational cost, thanks to its Bayesian hierarchical

  17. Extremely Preterm Birth

    Science.gov (United States)

    ... Events Advocacy For Patients About ACOG Extremely Preterm Birth Home For Patients Search FAQs Extremely Preterm Birth ... Spanish FAQ173, June 2016 PDF Format Extremely Preterm Birth Pregnancy When is a baby considered “preterm” or “ ...

  18. Ligand extraction of rare earth elements from aquifer sediments: Implications for rare earth element complexation with organic matter in natural waters

    Science.gov (United States)

    Tang, Jianwu; Johannesson, Karen H.

    2010-12-01

    The ability of organic matter as well as carbonate ions to extract rare earth elements (REEs) from sandy sediments of a Coastal Plain aquifer was investigated for unpurified organic matter from different sources (i.e., Mississippi River natural organic matter, Aldrich humic acid, Nordic aquatic fulvic acid, Suwannee River fulvic acid, and Suwannee River natural organic matter) and for extraction solutions containing weak (i.e., CH 3COO -) or strong (i.e., CO32-) ligands. The experimental results indicate that, in the absence of strong REE complexing ligands in solution, the amount of REEs released from the sand is small and the fractionation pattern of the released REEs appears to be controlled by the surface stability constants for REE sorption with Fe(III) oxides/oxyhydroxides. In the presence of strong solution complexing ligands, however, the amount and the fractionation pattern of the released REEs reflect the strength and variation of the stability constants of the dominant aqueous REE species across the REE series. The varying amount of REEs extracted by the different organic matter employed in the experiments indicates that organic matter from different sources has different complexing capacity for REEs. However, the fractionation pattern of REEs extracted by the various organic matter used in our experiments is remarkable consistent, being independent of the source and the concentration of organic matter used, as well as solution pH. Because natural aquifer sand and unpurified organic matter were used in our experiments, our experimental conditions are more broadly similar to natural systems than many previous laboratory experiments of REE-humic complexation that employed purified humic substances. Our results suggest that the REE loading effect on REE-humic complexation is negligible in natural waters as more abundant metal cations (e.g., Fe, Al) out-compete REEs for strong binding sites on organic matter. More specifically, our results indicate that REE

  19. Rapid formation of complexity in the total synthesis of natural products enabled by oxabicyclo[2.2.1]heptene building blocks.

    Science.gov (United States)

    Schindler, Corinna S; Carreira, Erick M

    2009-11-01

    This critical review showcases examples of rapid formation of complexity in total syntheses starting from 7-oxabicyclo[2.2.1]hept-5-ene derivatives. An overview of methods allowing synthetic access to these building blocks is provided and their application in recently developed synthetic transformations to structurally complex systems is illustrated. In addition, the facile access to a novel oxabicyclo[2.2.1]heptene derived building block is presented which significantly enlarges the possibilities of previously known chemical transformations and is highlighted in the enantioselective route to the core of the banyaside and suomilide natural products (107 references).

  20. Clinical Experience of Complex Application of Antiviral Therapy, Natural and Preformed Physical Factors in Patients with Chronic Hepatitis C

    Directory of Open Access Journals (Sweden)

    N.V. Dragomiretska

    2013-02-01

    Full Text Available The article deals with the results of complex application of antiviral therapy, low-mineralized hydrocarbonate-sulphate-chloride sodium mineral water, EHF- and vibroacoustic therapy of the patients with chronic viral hepatitis C. The developed complex liquidates adverse effects of the antiviral therapy (leukocytopenia, thrombocytopenia and flu-like syndromes, promotes the normalization of the functional tests of the liver and normalization of the majority of indicators of the immune status, stimulates the synthesis of the endogenous interferon α.

  1. Interpretation of complexometric titration data: An intercomparison of methods for estimating models of trace metal complexation by natural organic ligands

    NARCIS (Netherlands)

    Pižeta, I.; Sander, S.G.; Hudson, R.J.M.; Omanovic, D.; Baars, O.; Barbeau, K.A.; Buck, K.N.; Bundy, R.M.; Carrasco, G.; Croot, P.L.; Garnier, C.; Gerringa, L.J.A.; Gledhill, M.; Hirose, K.; Kondo, Y.; Laglera, L.M.; Nuester, J.; Rijkenberg, M.J.A.; Takeda, S.; Twining, B.S.; Wells, M.

    2015-01-01

    With the common goal of more accurately and consistently quantifying ambient concentrations of free metal ions and natural organic ligands in aquatic ecosystems, researchers from 15 laboratories that routinely analyze trace metal speciation participated in an intercomparison of statistical methods

  2. Complex analyses on clinical information systems using restricted natural language querying to resolve time-event dependencies.

    Science.gov (United States)

    Safari, Leila; Patrick, Jon D

    2018-06-01

    This paper reports on a generic framework to provide clinicians with the ability to conduct complex analyses on elaborate research topics using cascaded queries to resolve internal time-event dependencies in the research questions, as an extension to the proposed Clinical Data Analytics Language (CliniDAL). A cascaded query model is proposed to resolve internal time-event dependencies in the queries which can have up to five levels of criteria starting with a query to define subjects to be admitted into a study, followed by a query to define the time span of the experiment. Three more cascaded queries can be required to define control groups, control variables and output variables which all together simulate a real scientific experiment. According to the complexity of the research questions, the cascaded query model has the flexibility of merging some lower level queries for simple research questions or adding a nested query to each level to compose more complex queries. Three different scenarios (one of them contains two studies) are described and used for evaluation of the proposed solution. CliniDAL's complex analyses solution enables answering complex queries with time-event dependencies at most in a few hours which manually would take many days. An evaluation of results of the research studies based on the comparison between CliniDAL and SQL solutions reveals high usability and efficiency of CliniDAL's solution. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. The complex nature of mixed farming systems requires multidimensional actions supported by integrative research and development efforts

    DEFF Research Database (Denmark)

    González-García, E; Gourdine, J L; Alexandre, G

    2012-01-01

    the requirement for a change in research strategies and initiatives through the development of a complex but necessary multi-/inter-/trans-disciplinary teamwork spirit. We stress as essential the collaboration and active participation of local and regional actors, stakeholders and end-users in the identification...

  4. Hydrogen bonded C-H···Y (Y = O, S, Hal) molecular complexes: A natural bond orbital analysis

    Science.gov (United States)

    Isaev, A. N.

    2016-03-01

    Hydrogen bonded C-H···Y complexes formed by H2O, H2S molecules, hydrogen halides, and halogen-ions with methane, halogen substituted methane as well as with the C2H2 and NCH molecules were studied at the MP2/aug-cc-pVDZ level. The structure of NBOs corresponding to lone pair of acceptor Y, n Y, and vacant anti-σ-bond C-H of proton donor was analyzed and estimates of second order perturbation energy E(2) characterizing donor-acceptor n Y → σ C-H * charge-transfer interaction were obtained. Computational results for complexes of methane and its halogen substituted derivatives show that for each set of analogous structures, the EnY→σ*C-H (2) energy tends to grow with an increase in the s-component percentage in the lone pair NBO of acceptor Y. Calculations for different C···Y distances show that the equilibrium geometries of complexes lie in the region where the E(2) energy is highest and it changes symbatically with the length of the covalent E-H bond when the R(C···Y) distance is varied. The performed analysis allows us to divide the hydrogen bonded complexes into two groups, depending on the pattern of overlapping for NBOs of the hydrogen bridge.

  5. The Adaptive Nature of the Bone-Periodontal Ligament-Cementum Complex in a Ligature-Induced Periodontitis Rat Model

    Directory of Open Access Journals (Sweden)

    Ji-Hyun Lee

    2013-01-01

    Full Text Available The novel aspect of this study involves illustrating significant adaptation of a functionally loaded bone-PDL-cementum complex in a ligature-induced periodontitis rat model. Following 4, 8, and 15 days of ligation, proinflammatory cytokines (TNF-α and RANKL, a mineral resorption indicator (TRAP, and a cell migration and adhesion molecule for tissue regeneration (fibronectin within the complex were localized and correlated with changes in PDL-space (functional space. At 4 days of ligation, the functional space of the distal complex was widened compared to controls and was positively correlated with an increased expression of TNF-α. At 8 and 15 days, the number of RANKL(+ cells decreased near the mesial alveolar bone crest (ABC but increased at the distal ABC. TRAP(+ cells on both sides of the complex significantly increased at 8 days. A gradual change in fibronectin expression from the distal PDL-secondary cementum interfaces through precementum layers was observed when compared to increased and abrupt changes at the mesial PDL-cementum and PDL-bone interfaces in ligated and control groups. Based on our results, we hypothesize that compromised strain fields can be created in a diseased periodontium, which in response to prolonged function can significantly alter the original bone and apical cementum formations.

  6. A functional mimic of natural peroxidases : synthesis and catalytic activity of a non-heme iron peptide hydroperoxide complex

    NARCIS (Netherlands)

    Choma, CT; Schudde, EP; Kellogg, RM; Robillard, GT; Feringa, BL

    1998-01-01

    Site-selective attachment of unprotected peptides to a non-heme iron complex is achieved by displacing two halides on the catalyst by peptide caesium thiolates, This coupling approach should be compatible with any peptide sequence provided there is only a single reduced cysteine. The oxidation

  7. Influence of humic acids on the migration behavior of radioactive and non-radioactive substances under conditions close to nature. Synthesis, radiometric determination of functional groups, complexation

    International Nuclear Information System (INIS)

    Pompe, S.; Bubner, M.; Schmeide, K.; Heise, K.H.; Bernhard, G.; Nitsche, H.

    2000-04-01

    The interaction behavior of humic acids with uranium(VI) and the influence of humic substances on the migration behavior of uranium was investigated. A main focus of this work was the synthesis of four different humic acid model substances and their characterization and comparison to the natural humic acid from Aldrich. A radiometric method for the determination of humic acid functional groups was applied in addition to conventional methods for the determination of the functionality of humic acids. The humic acid model substances show functional and structural properties comparable to natural humic acids. Modified humic acids with blocked phenolic OH were synthesized to determine the influence of phenolic OH groups on the complexation behavior of humic acids. A synthesis method for 14 C-labeled humic acids with high specific activity was developed. The complexation behavior of synthetic and natural humic acids with uranium(VI) was investigated by X-ray absorption spectroscopy, laser-induced fluorescence spectroscopy and FTIR spectroscopy. The synthetic model substances show an interaction behavior with uranium(VI) that is comparable to natural humic acids. This points to the fact that the synthetic humic acids simulate the functionality of their natural analogues very well. For the first time the influence of phenolic OH groups on the complexation behavior of humic acids was investigated by applying a modified humic acid with blocked phenolic OH groups. The formation of a uranyl hydroxy humate complex was identified by laserspectroscopic investigations of the complexation of Aldrich humic acid with uranium(VI) at pH7. The migration behavior of uranium in a sandy aquifer system rich in humic substances was investigated in column experiments. A part of uranium migrates non-retarded through the sediment, bound to humic colloids. The uranium migration behavior is strongly influenced by the kinetically controlled interaction processes of uranium with the humic colloids

  8. Natural and EDTA-complexed lanthanides used as a geochemical probe for aquifers: a case study of Orleans valley's alluvial and karstic aquifers

    International Nuclear Information System (INIS)

    Le Borgne, F.; Treuil, M.; Joron, J.L.; Lepiller, M.

    2005-01-01

    The transit of chemical elements within the different parts of Orleans valley's aquifer is studied by two complementary methods. Those methods rely on the fractionation of lanthanides (Ln) during their migration in natural waters. The first method consists in studying natural lanthanides patterns within the watershed, at its entries and exits. second one lies on multi-tracer experiments with Ln-EDTA complexes. This work is completed through an observation network consisting of 52 piezometers set on a sand and gravel quarry, and the natural entries and exits of the aquifer. Orleans valley's aquifer, which is made of an alluvial watershed lying on a karstic aquifer, is mainly fed by Loire river via a large karstic network. At the entries of the aquifer (Loire river at Jargeau), the Ln concentrations in the dissolved fraction ( heavy Ln. On the other hand, the filtration of alluvial groundwater with high colloids content induces no significant Ln fractionation when the solution contains no strong chelating agent. Hence, the transit of natural and artificial Ln in Orleans valley aquifer can be explained by two complementary processes. (I) Decanting/filtering or, on the opposite, stirring of colloids. Those processes induce no important Ln fractionation. (2) Exchanges of Ln between solute complexes, colloids and sediments due to the presence of strong chelating agents. Those exchanges fractionate the Ln in the order of their stability constants. Considering the natural Ln fractionation that occurs in the Loire river and in the studied aquifer, the carbonates, the stability constants of which follow the order light Ln < heavy Ln, are the best candidates as natural strong chelating agents. From the hydrodynamic point of view, both tracer experiments and natural Ln concentrations show that the transfer of elements within the alluvial watershed is pulsed by the Loire river movements. During an ascent phase, the elements migrate away from and perpendicularly to the karstic

  9. On the nature of Ni···Ni interaction in a model dimeric Ni complex.

    Science.gov (United States)

    Kamiński, Radosław; Herbaczyńska, Beata; Srebro, Monika; Pietrzykowski, Antoni; Michalak, Artur; Jerzykiewicz, Lucjan B; Woźniak, Krzysztof

    2011-06-07

    A new dinuclear complex (NiC(5)H(4)SiMe(2)CHCH(2))(2) (2) was prepared by reacting nickelocene derivative [(C(5)H(4)SiMe(2)CH=CH(2))(2)Ni] (1) with methyllithium (MeLi). Good quality crystals were subjected to a high-resolution X-ray measurement. Subsequent multipole refinement yielded accurate description of electron density distribution. Detailed inspection of experimental electron density in Ni···Ni contact revealed that the nickel atoms are bonded and significant deformation of the metal valence shell is related to different populations of the d-orbitals. The existence of the Ni···Ni bond path explains the lack of unpaired electrons in the complex due to a possible exchange channel.

  10. Evaluating the Nature of So-Called S*-State Feature in Transient Absorption of Carotenoids in Light-Harvesting Complex 2 (LH2) from Purple Photosynthetic Bacteria.

    Science.gov (United States)

    Niedzwiedzki, Dariusz M; Hunter, C Neil; Blankenship, Robert E

    2016-11-03

    Carotenoids are a class of natural pigments present in all phototrophic organisms, mainly in their light-harvesting proteins in which they play roles of accessory light absorbers and photoprotectors. Extensive time-resolved spectroscopic studies of these pigments have revealed unexpectedly complex photophysical properties, particularly for carotenoids in light-harvesting LH2 complexes from purple bacteria. An ambiguous, optically forbidden electronic excited state designated as S* has been postulated to be involved in carotenoid excitation relaxation and in an alternative carotenoid-to-bacteriochlorophyll energy transfer pathway, as well as being a precursor of the carotenoid triplet state. However, no definitive and satisfactory origin of the carotenoid S* state in these complexes has been established, despite a wide-ranging series of studies. Here, we resolve the ambiguous origin of the carotenoid S* state in LH2 complex from Rba. sphaeroides by showing that the S* feature can be seen as a combination of ground state absorption bleaching of the carotenoid pool converted to cations and the Stark spectrum of neighbor neutral carotenoids, induced by temporal electric field brought by the carotenoid cation-bacteriochlorophyll anion pair. These findings remove the need to assign an S* state, and thereby significantly simplify the photochemistry of carotenoids in these photosynthetic antenna complexes.

  11. A comparative study of the spectral, fluorometric properties and photostability of natural curcumin, iron- and boron- complexed curcumin

    Science.gov (United States)

    Mohammed, Fatima; Rashid-Doubell, Fiza; Cassidy, Seamas; Henari, Fryad

    2017-08-01

    Curcumin is a yellow phenolic compound with a wide range of reported biological effects. However, two main obstacles hinder the use of curcumin therapeutically, namely its poor bioavailability and photostability. We have synthesized two curcumin complexes, the first a boron curcumin complex (B-Cur2) and the second an iron (Fe-Cur3) complex of curcumin. Both derivatives showed high fluorescence efficiency (quantum yield) and greater photostability in solution. The improved photostability could be attributed to the coordination structures and the removal of β-diketone group from curcumin. The fluorescence and ultra violet/visible absorption spectra of curcumin, B-Cur2 and Fe-Cur3 all have a similar spectral pattern when dissolved in the same organic solvent. However, a shift towards a lower wavelength was observed when moving from polar to non-polar solvents, possibly due to differences in solvent polarity. A plot of Stokes' shift vs the orientation polarity parameter (Δf) or vs the solvent polarity parameter (ET 30) showed an improved correlation between the solvent polarity parameter than with the orientation polarity parameter and indicating that the red shift observed could be due to hydrogen-bonding between the solvent molecules. A similar association was obtained when Stokes' shift was replaced by maximum synchronous fluorescence. Both B-Cur2 and Fe-Cur3 had larger quantum yields than curcumin, suggesting they may be good candidates for medical imaging and in vitro studies.

  12. Meaning and Forms of Political Extremism

    Directory of Open Access Journals (Sweden)

    Uwe Backes

    2007-12-01

    Full Text Available The article seeks to contribute to the conceptualisation of political extremism and to lay a foundation for further theoretical studies which are explanatory in nature. A sketch of the history of the concepts follows a discussion of structural characteristics and then a typological examination of forms of extremism, particularly those of the 20th and 21st century.

  13. Models and Inference for Multivariate Spatial Extremes

    KAUST Repository

    Vettori, Sabrina

    2017-01-01

    The development of flexible and interpretable statistical methods is necessary in order to provide appropriate risk assessment measures for extreme events and natural disasters. In this thesis, we address this challenge by contributing

  14. Complex analysis of hazards to the man and natural environment due to electricity production in nuclear and coal power plants

    International Nuclear Information System (INIS)

    Strupczewski, A.

    1990-01-01

    The report presents a complex analysis of hazards connected with electrical energy production in nuclear power plants and coal power plants, starting with fuel mining, through power plant construction, operation, possible accidents and decommissioning to long term global effects. The comparison is based on contemporary, proven technologies of coal fired power plants and nuclear power plants with pressurized water reactors. The hazards to environment and man due to nuclear power are shown to be much smaller than those due to coal power cycle. The health benefits due to electrical power availability are shown to be much larger than the health losses due to its production. (author). 71 refs, 17 figs, 12 tabs

  15. Multidimensional profiling of components in complex mixtures of natural products for metabolic analysis, proof of concept: application to Quillaja saponins.

    Science.gov (United States)

    Bankefors, Johan; Nord, Lars I; Kenne, Lennart

    2010-02-01

    A method for separation and detection of major and minor components in complex mixtures has been developed, utilising two-dimensional high-performance liquid chromatography (2D-HPLC) combined with electrospray ionisation ion-trap multiple-stage mass spectrometry (ESI-ITMS(n)). Chromatographic conditions were matched with mass spectrometric detection to maximise the number of components that could be separated. The described procedure has proven useful to discern several hundreds of saponin components when applied to Quillaja saponaria Molina bark extracts. The discrimination of each saponin component relies on the fact that three coordinates (x, y, z) for each component can be derived from the retention time of the two chromatographic steps (x, y) and the m/z-values from the multiple-stage mass spectrometry (z(n), n=1, 2, ...). Thus an improved graphical representation was obtained by combining retention times from the two-stage separation with +MS(1) (z(1)) and the additional structural information from the second mass stage +MS(2) (z(2), z(3)) corresponding to the main fragment ions. By this approach three-dimensional plots can be made that reveal both the chromatographic and structural properties of a specific mixture which can be useful in fingerprinting of complex mixtures. 2009 Elsevier B.V. All rights reserved.

  16. Landscape Aesthetics and the Scenic Drivers of Amenity Migration in the New West: Naturalness, Visual Scale, and Complexity

    Directory of Open Access Journals (Sweden)

    Jelena Vukomanovic

    2014-04-01

    Full Text Available Values associated with scenic beauty are common “pull factors” for amenity migrants, however the specific landscape features that attract amenity migration are poorly understood. In this study we focused on three visual quality metrics of the intermountain West (USA, with the objective of exploring the relationship between the location of exurban homes and aesthetic landscape preference, as exemplified through greenness, viewshed size, and terrain ruggedness. Using viewshed analysis, we compared the viewsheds of actual exurban houses to the viewsheds of randomly-distributed simulated (validation houses. We found that the actual exurban households can see significantly more vegetation and a more rugged (complex terrain than simulated houses. Actual exurban homes see a more rugged terrain, but do not necessarily see the highest peaks, suggesting that visual complexity throughout the viewshed may be more important. The viewsheds visible from the actual exurban houses were significantly larger than those visible from the simulated houses, indicating that visual scale is important to the general aesthetic experiences of exurbanites. The differences in visual quality metric values between actual exurban and simulated viewsheds call into question the use of county-level scales of analysis for the study of landscape preferences, which may miss key landscape aesthetic drivers of preference.

  17. Nephelauxetic and hypersensitive nature of neodymium(III) complexes with α-pyridyl-thiosemicarbazide and its furfural-2-aldehyde and thiophene-2-aldehyde derivatives

    International Nuclear Information System (INIS)

    Jain, C.L.; Mundley, P.N.; Khandelwal, B.E.

    1986-01-01

    A new series of octahedral Nd(III) complexes with recently synthesised α-pyridylthiosemicarbazide (C 6 H 8 N 4 S or 'PT'), N-(α-pyridyl)furfural-2-aldehyde-thiosemicarbazone (C 11 H 10 N 4 SO or 'PFT') and N-(α-pyridyl)thiophene-2-aldehyde-thiosemicarbazone (C 11 H 10 N 4 S 2 or 'PTT'), have been isolated and characterised on the basis of their elemental analysis, magnetic and reflectance and ir spectral data revealing 'PT' as bidentate (pyridinic-N and thioketo-S) and 'PFT' and 'PTT' as tetradentate with pyridinic-N, thioketo-S, imine-N and furfuryl-O/thiophenyl-S as donor sites. Isolation and characterisation of Nd(III) complexes with 'PT', 'PFT' and 'PTT' and their nephelauxetic and hypersensitive nature are studied in order to evaluate the stereochemistry of the ligands around Nd(III) ion. (author). 12 refs., 2 tables

  18. Absence of Non-histone Protein Complexes at Natural Chromosomal Pause Sites Results in Reduced Replication Pausing in Aging Yeast Cells

    Directory of Open Access Journals (Sweden)

    Marleny Cabral

    2016-11-01

    Full Text Available There is substantial evidence that genomic instability increases during aging. Replication pausing (and stalling at difficult-to-replicate chromosomal sites may induce genomic instability. Interestingly, in aging yeast cells, we observed reduced replication pausing at various natural replication pause sites (RPSs in ribosomal DNA (rDNA and non-rDNA locations (e.g., silent replication origins and tRNA genes. The reduced pausing occurs independent of the DNA helicase Rrm3p, which facilitates replication past these non-histone protein-complex-bound RPSs, and is independent of the deacetylase Sir2p. Conditions of caloric restriction (CR, which extend life span, also cause reduced replication pausing at the 5S rDNA and at tRNA genes. In aged and CR cells, the RPSs are less occupied by their specific non-histone protein complexes (e.g., the preinitiation complex TFIIIC, likely because members of these complexes have primarily cytosolic localization. These conditions may lead to reduced replication pausing and may lower replication stress at these sites during aging.

  19. Nitrogen complex species and its chemical nature in TiO2 for visible-light sensitized photocatalysis

    International Nuclear Information System (INIS)

    Asahi, Ryoji; Morikawa, Takeshi

    2007-01-01

    A photocatalyst with high reactivity under visible-light has been desired to utilize solar irradiation or interior lighting efficiently. Nitrogen-doped TiO 2 revealed significant improvement in optical absorption and photocatalytic activity over TiO 2 under visible light. We have performed the first-principles calculations to study the detailed N complex species introduced in TiO 2 . The results include stable geometries, densities of states, formation energies, and core levels. The present systematic studies account for the long-term controversial issue on N-doped TiO 2 , in particular, regarding the detailed assignment of N 1s binding energies observed in the XPS measurement. The detailed analyses of the formation energies show that introducing the N species more in a controlled way via process conditions is crucial to achieve the optimized photocatalytic performance

  20. XRCC1 coordinates disparate responses and multiprotein repair complexes depending on the nature and context of the DNA damage

    DEFF Research Database (Denmark)

    Hanssen-Bauer, Audun; Solvang-Garten, Karin; Sundheim, Ottar

    2011-01-01

    . We demonstrate that the laser dose used for introducing DNA damage determines the repertoire of DNA repair proteins recruited. Furthermore, we demonstrate that recruitment of POLß and PNK to regions irradiated with low laser dose requires XRCC1 and that inhibition of PARylation by PARP......-inhibitors only slightly reduces the recruitment of XRCC1, PNK, or POLß to sites of DNA damage. Recruitment of PCNA and FEN-1 requires higher doses of irradiation and is enhanced by XRCC1, as well as by accumulation of PARP-1 at the site of DNA damage. These data improve our understanding of recruitment of BER......XRCC1 is a scaffold protein capable of interacting with several DNA repair proteins. Here we provide evidence for the presence of XRCC1 in different complexes of sizes from 200 to 1500 kDa, and we show that immunoprecipitates using XRCC1 as bait are capable of complete repair of AP sites via both...

  1. Scienti fi c Approaches and Methods in the Investigation of the Formation and Stability of Hydromorphic Natural Complexes of the Irtysh River Valley System (The Kazakhstan Part

    Directory of Open Access Journals (Sweden)

    A. G. Tsaregorodtseva

    2006-12-01

    Full Text Available The current geo-environmental situation of the Irtysh River valley system is connected with the high degree of control of the river drainage, which affects the functioning of its entire ecosystem and determines some morphological features of its channel. In the present work, the methodological approaches in the study of formation of the valley’s hydromorphic natural complexes are discussed, and the results of studies on the channel processes in the middle course of the Irtysh River are given.

  2. The logic, experimental steps, and potential of heterologous natural product biosynthesis featuring the complex antibiotic erythromycin A produced through E. coli.

    Science.gov (United States)

    Jiang, Ming; Zhang, Haoran; Pfeifer, Blaine A

    2013-01-13

    The heterologous production of complex natural products is an approach designed to address current limitations and future possibilities. It is particularly useful for those compounds which possess therapeutic value but cannot be sufficiently produced or would benefit from an improved form of production. The experimental procedures involved can be subdivided into three components: 1) genetic transfer; 2) heterologous reconstitution; and 3) product analysis. Each experimental component is under continual optimization to meet the challenges and anticipate the opportunities associated with this emerging approach. Heterologous biosynthesis begins with the identification of a genetic sequence responsible for a valuable natural product. Transferring this sequence to a heterologous host is complicated by the biosynthetic pathway complexity responsible for product formation. The antibiotic erythromycin A is a good example. Twenty genes (totaling >50 kb) are required for eventual biosynthesis. In addition, three of these genes encode megasynthases, multi-domain enzymes each ~300 kDa in size. This genetic material must be designed and transferred to E. coli for reconstituted biosynthesis. The use of PCR isolation, operon construction, multi-cystronic plasmids, and electro-transformation will be described in transferring the erythromycin A genetic cluster to E. coli. Once transferred, the E. coli cell must support eventual biosynthesis. This process is also challenging given the substantial differences between E. coli and most original hosts responsible for complex natural product formation. The cell must provide necessary substrates to support biosynthesis and coordinately express the transferred genetic cluster to produce active enzymes. In the case of erythromycin A, the E. coli cell had to be engineered to provide the two precursors (propionyl-CoA and (2S)-methylmalonyl-CoA) required for biosynthesis. In addition, gene sequence modifications, plasmid copy number

  3. Preconcentration and Determination of Copper and Zinc in Natural Water Samples by ICP-AES After Complexation and Sorption on Amberlite XAD-2

    Directory of Open Access Journals (Sweden)

    Ferreira Sérgio Luis Costa

    1998-01-01

    Full Text Available The present paper describes a procedure for separation, preconcentration and sequential determination of trace amounts of copper and zinc in natural water samples, by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES. The proposed method is based on the complexation of copper(II and zinc(II ions by 1-(2-thiazolylazo-2-naphthol (TAN and sorption on to Amberlite XAD-2 resin. Parameters such as: TAN amount, pH effect on the complexation and sorption of TAN complexes, agitation time for complete sorption, concentration of metal ion, mass of Amberlite XAD-2, desorption of metal ions from XAD-2 resin and sample volume were studied. The results demonstrated that the copper(II and zinc(II ions, in the range of 0.10 to 100.00 mug, contained in a solution sample volume of 400 mL, in the pH range of 5.7 to 8.3, on the form of TAN complexes had been quantitatively retained on to XAD-2 resin. The shaking time required for sorption is 1 h using a resin mass of 1.4 g. The solution for determination of copper and zinc by ICP-AES is obtained, after desorption of the ions from the XAD-2 resin, using 5 mL of 2 mol L-1 hydrochloric acid and shaking the system for 5 min. The procedure was applied to the determination of copper and zinc in several natural water samples. The standard addition technique was applied and the obtained recoveries revealed that the proposed procedure has a good accuracy. A high enrichment factor (80 and simplicity are the main advantages in this analytical protocol.

  4. Significance of the tropical fire ant Solenopsis geminata (hymenoptera: formicidae) as part of the natural enemy complex responsible for successful biological control of many tropical irrigated rice pests.

    Science.gov (United States)

    Way, M J; Heong, K L

    2009-10-01

    The tropical fire ant Solenopsis geminata (Fabricius) often nests very abundantly in the earthen banks (bunds) around irrigated rice fields in the tropics. Where some farmers habitually drain fields to the mud for about 3-4 days, the ants can quickly spread up to about 20 m into the fields where they collect food, including pest prey such as the eggs and young of the apple snail Pomacea caniculata (Lamarck) and insects such as lepidopterous larvae and hoppers, notably Nilaparvata lugens (Stäl) the brown planthopper (Bph) and green leafhoppers Nephotettix spp. Even in drained fields, the activity of S. geminata is restricted by rainfall in the wet season. The relatively few ant workers that forage characteristically into drained fields and on to the transplanted clumps of rice plants (hills) kill the normally few immigrant Bph adults but are initially slower acting than other species of the natural enemy complex. However, larger populations of Bph are fiercely attacked and effectively controlled by rapidly recruited ant workers; whereas, in the absence of the ant, the other natural enemies are inadequate. In normal circumstances, there is no ant recruitment in response to initially small populations of immigrant Bph and no evidence of incompatibility between ant foragers and other natural enemies such as spiders. However, when many ants are quickly and aggressively recruited to attack large populations of Bph, they temporarily displace some spiders from infested hills. It is concluded that, in suitable weather conditions and even when insecticides kill natural enemies within the rice field, periodic drainage that enables S. geminata to join the predator complex is valuable for ant-based control of pests such as snails and Lepidoptera, and especially against relatively large populations of Bph. Drainage practices to benefit ants are fully compatible with recent research, which shows that periodic drainage combats problems of 'yield decline' in intensively irrigated

  5. Extreme environment electronics

    CERN Document Server

    Cressler, John D

    2012-01-01

    Unfriendly to conventional electronic devices, circuits, and systems, extreme environments represent a serious challenge to designers and mission architects. The first truly comprehensive guide to this specialized field, Extreme Environment Electronics explains the essential aspects of designing and using devices, circuits, and electronic systems intended to operate in extreme environments, including across wide temperature ranges and in radiation-intense scenarios such as space. The Definitive Guide to Extreme Environment Electronics Featuring contributions by some of the world's foremost exp

  6. Getting Alice through the door: social science research and natural resource management

    Science.gov (United States)

    Alan W. Ewert

    1995-01-01

    A number of trends are altering the role of science in natural resource management. These trends include the growing political power of science, the recognition that most natural resource problems are extremely complex and not prone to uni-dimensional solutions, and the increasing need to integrate an understanding of the human component into the planning and decision-...

  7. 3D terrestrial lidar data classification of complex natural scenes using a multi-scale dimensionality criterion: Applications in geomorphology

    Science.gov (United States)

    Brodu, N.; Lague, D.

    2012-03-01

    3D point clouds of natural environments relevant to problems in geomorphology (rivers, coastal environments, cliffs, …) often require classification of the data into elementary relevant classes. A typical example is the separation of riparian vegetation from ground in fluvial environments, the distinction between fresh surfaces and rockfall in cliff environments, or more generally the classification of surfaces according to their morphology (e.g. the presence of bedforms or by grain size). Natural surfaces are heterogeneous and their distinctive properties are seldom defined at a unique scale, prompting the use of multi-scale criteria to achieve a high degree of classification success. We have thus defined a multi-scale measure of the point cloud dimensionality around each point. The dimensionality characterizes the local 3D organization of the point cloud within spheres centered on the measured points and varies from being 1D (points set along a line), 2D (points forming a plane) to the full 3D volume. By varying the diameter of the sphere, we can thus monitor how the local cloud geometry behaves across scales. We present the technique and illustrate its efficiency in separating riparian vegetation from ground and classifying a mountain stream as vegetation, rock, gravel or water surface. In these two cases, separating the vegetation from ground or other classes achieve accuracy larger than 98%. Comparison with a single scale approach shows the superiority of the multi-scale analysis in enhancing class separability and spatial resolution of the classification. Scenes between 10 and one hundred million points can be classified on a common laptop in a reasonable time. The technique is robust to missing data, shadow zones and changes in point density within the scene. The classification is fast and accurate and can account for some degree of intra-class morphological variability such as different vegetation types. A probabilistic confidence in the classification

  8. Infection in the ischemic lower extremity.

    Science.gov (United States)

    Fry, D E; Marek, J M; Langsfeld, M

    1998-06-01

    Infections in the lower extremity of the patient with ischemia can cover a broad spectrum of different diseases. An understanding of the particular pathophysiologic circumstances in the ischemic extremity can be of great value in understanding the natural history of the disease and the potential complications that may occur. Optimizing blood flow to the extremity by using revascularization techniques is important for any patient with an ischemic lower extremity complicated by infection or ulceration. Infections in the ischemic lower extremity require local débridement and systemic antibiotics. For severe infections, such as necrotizing fasciitis or the fetid foot, more extensive local débridement and even amputation may be required. Fundamentals of managing prosthetic graft infection require removing the infected prosthesis, local wound débridement, and systemic antibiotics while attempting to preserve viability of the lower extremity using autogenous graft reconstruction.

  9. Native trees of the Northeast Argentine: natural hosts of the Cryptococcus neoformans-Cryptococcus gattii species complex.

    Science.gov (United States)

    Cattana, Maria Emilia; Sosa, María de Los Ángeles; Fernández, Mariana; Rojas, Florencia; Mangiaterra, Magdalena; Giusiano, Gustavo

    2014-01-01

    In Argentina, information about epidemiology and environmental distribution of Cryptococcus is scarce. The city of Resistencia borders with Brazil and Paraguay where this fungus is endemic. All these supported the need to investigate the ecology of the genus and the epidemiology of cryptococcosis in this area. The aim was to investigate the presence of species of Cryptococcus neoformans-Cryptococcus gattii complex and their genotypes in trees of the city of Resistencia. One hundred and five trees were sampled by swabbing technique. The isolates were identified using conventional and commercial methods and genotyped by PCR-RFLP (Restriction Fragment Length Polymorphism). Cryptococcus was found in 7 out of the total trees. 6 out of 7 Cryptococcus isolates were identified as C. neoformans and one as C. gattii. C. gattii was isolated from Grevillea robusta. C. neoformans strains were isolated from Tabebuia avellanedae and Peltophorum dubium. Genotyping showed that all C. neoformans belonged to the VNI type and C. gattii belonged to the VGI type. This represents the first study on the ecology of Cryptococcus spp. associated to trees from northeastern Argentina, and the first report describing Grevillea robusta as a host of members of this fungal genus. Another finding is the isolation of C. neoformans from Tabebuia avellanedae and Peltophorum dubium, both tree species native to northeastern Argentina. Copyright © 2012 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  10. A high-resolution 7-Tesla fMRI dataset from complex natural stimulation with an audio movie.

    Science.gov (United States)

    Hanke, Michael; Baumgartner, Florian J; Ibe, Pierre; Kaule, Falko R; Pollmann, Stefan; Speck, Oliver; Zinke, Wolf; Stadler, Jörg

    2014-01-01

    Here we present a high-resolution functional magnetic resonance (fMRI) dataset - 20 participants recorded at high field strength (7 Tesla) during prolonged stimulation with an auditory feature film ("Forrest Gump"). In addition, a comprehensive set of auxiliary data (T1w, T2w, DTI, susceptibility-weighted image, angiography) as well as measurements to assess technical and physiological noise components have been acquired. An initial analysis confirms that these data can be used to study common and idiosyncratic brain response patterns to complex auditory stimulation. Among the potential uses of this dataset are the study of auditory attention and cognition, language and music perception, and social perception. The auxiliary measurements enable a large variety of additional analysis strategies that relate functional response patterns to structural properties of the brain. Alongside the acquired data, we provide source code and detailed information on all employed procedures - from stimulus creation to data analysis. In order to facilitate replicative and derived works, only free and open-source software was utilized.

  11. The political economy of corporate social responsibility and community development: a case study of Norway's Snoehvit natural gas complex

    Energy Technology Data Exchange (ETDEWEB)

    Klick, Matthew T

    2009-07-01

    This project uses stakeholder evidence from semi-structured interviews to analyze the relative effectiveness of an oil company's stated 'corporate social responsibility' (CSR) initiatives in a new, Arctic host community. Specifically, this project analyzes the outcomes of StatoilHydro initiatives to date in Hammerfest, Norway, where the Snoehvit (Snow White) natural gas project began production in 2007. It gauges the ability of 'socially responsible' approaches to development to internalize negative externalisation and promote positive 'spin-offs'. Arctic countries are increasingly prioritizing petroleum development. The convergence of dramatic climate change, increasing energy demands, and high energy prices has made the Arctic an alluring frontier for the oil industry and Arctic governments. Small Arctic communities are increasingly playing host to large energy projects with the potential for dramatic cultural, social, environmental, and economic upheaval, but also economic growth and increased human capital. In this case study, CSR initiatives resulted in a broader accounting of social costs and benefits, an outcome that better internalized externalities, and pareto-improving trades between stakeholders and industry. (Author). 87 refs., 5 figs., 5 tabs

  12. Impact of uranyl-calcium-carbonato complexes on uranium(VI) adsorption to synthetic and natural sediments.

    Science.gov (United States)

    Stewart, Brandy D; Mayes, Melanie A; Fendorf, Scott

    2010-02-01

    Adsorption on soil and sediment solids may decrease aqueous uranium concentrations and limit its propensity for migration in natural and contaminated settings. Uranium adsorption will be controlled in large part by its aqueous speciation, with a particular dependence on the presence of dissolved calcium and carbonate. Here we quantify the impact of uranyl speciation on adsorption to both goethite and sediments from the Hanford Clastic Dike and Oak Ridge Melton Branch Ridgetop formations. Hanford sediments were preconditioned with sodium acetate and acetic acid to remove carbonate grains, and Ca and carbonate were reintroduced at defined levels to provide a range of aqueous uranyl species. U(VI) adsorption is directly linked to UO(2)(2+) speciation, with the extent of retention decreasing with formation of ternary uranyl-calcium-carbonato species. Adsorption isotherms under the conditions studied are linear, and K(d) values decrease from 48 to 17 L kg(-1) for goethite, from 64 to 29 L kg (-1) for Hanford sediments, and from 95 to 51 L kg(-1) for Melton Branch sediments as the Ca concentration increases from 0 to 1 mM at pH 7. Our observations reveal that, in carbonate-bearing waters, neutral to slightly acidic pH values ( approximately 5) and limited dissolved calcium are optimal for uranium adsorption.

  13. A stochastic model for the synthesis and degradation of natural organic matter. Part III: Modeling Cu(II) complexation

    Energy Technology Data Exchange (ETDEWEB)

    Cabaniss, Stephen E. [Department of Chemistry, University of New Mexico, Albuquerque, NM 87131 (United States)], E-mail: cabaniss@unm.edu; Maurice, Patricia A. [Department of Geology and Civil Engineering, University of Notre Dame (United States); Madey, Greg [Department of Computer Science, University of Notre Dame (United States)

    2007-08-15

    An agent-based biogeochemical model has been developed which begins with biochemical precursor molecules and simulates the transformation and degradation of natural organic matter (NOM). This manuscript presents an empirical quantitative structure activity relationship (QSAR) which uses the numbers of ligand groups, charge density and heteroatom density of a molecule to estimate Cu-binding affinity (K{sub Cu}{sup '}) at pH 7.0 and ionic strength 0.10 for the molecules in this model. Calibration of this QSAR on a set of 41 model compounds gives a root mean square error of 0.88 log units and r{sup 2} 0.93. Two simulated NOM assemblages, one beginning with small molecules (tannins, terpenoids, flavonoids) and one with biopolymers (protein, lignin), give markedly different distributions of logK{sub Cu}{sup '}. However, calculations based on these logK{sub Cu}{sup '} distributions agree qualitatively with published experimental Cu(II) titration data from river and lake NOM samples.

  14. Covalent lanthanide(III) macrocyclic complexes: the bonding nature and optical properties of a promising single antenna molecule.

    Science.gov (United States)

    Rabanal-León, Walter A; Páez-Hernández, Dayán; Arratia-Pérez, Ramiro

    2014-12-21

    The present work is focused on the elucidation of the electronic structure, bonding nature and optical properties of a series of low symmetry (C2) coordination compounds of type [Ln(III)HAM](3+), where "Ln(III)" are the trivalent lanthanide ions: La(3+), Ce(3+), Eu(3+) and Lu(3+), while "HAM" is the neutral six-nitrogen donor macrocyclic ligand [C22N6H26]. This systematic study has been performed in the framework of the Relativistic Density Functional Theory (R-DFT) and also using a multi-reference approach via the Complete Active Space (CAS) wavefunction treatment with the aim of analyzing their ground state and excited state electronic structures as well as electronic correlation. Furthermore, the use of the energy decomposition scheme proposed by Morokuma-Ziegler and the electron localization function (ELF) allows us to characterize the bonding between the lanthanide ions and the macrocyclic ligand, obtaining as a result a dative-covalent interaction. Due to a great deal of lanthanide optical properties and their technological applications, the absorption spectra of this set of coordination compounds were calculated using the time-dependent density functional theory (TD-DFT), where the presence of the intense Ligand to Metal Charge Transfer (LMCT) bands in the ultraviolet and visible region and the inherent f-f electronic transitions in the Near-Infra Red (NIR) region for some lanthanide ions allow us to propose these systems as "single antenna molecules" with potential applications in NIR technologies.

  15. Prospective outcome of the influence of complexation by natural organic matter on enhanced or retarded transport of radionuclides: case of humic substances retention

    International Nuclear Information System (INIS)

    Reiller, P.

    2010-01-01

    This document takes a prospective stock of the natural organic matter influence on the possible effects on radionuclide migration, as well as a brief critical analysis of the literature data. A comparison with the retention of the 'simple' organic complexing agents is done in order to fix the limit of the 'simplistic' analogies done in the literature very often. It appears that the magnitude of the effects is function of the residence time in the medium, and of the possibilities for the organic complexes to be retained on the mineral surfaces. The contact time between radionuclides and the natural organic matter is also an influent parameter, as it influences part of the reversibility of this interaction vis-a-vis surface retention. Modelling of the metal-organic-surface systems is only satisfying up to now when accounting fractions of organic matter that are less susceptible to form colloidal aggregates, i.e., fulvic acids. These non-aggregated fractions could be considered as simple ligands in a first approximation. Conversely, when it comes to aggregated colloids of organic origin, i.e., humic acids, modelling are limited by the lack of theoretical understanding of their structure and of their evolution in response to geochemical condition variations, as ionic strength (harsh meteoric events), acidity or water composition (non-saturated water table). (author)

  16. Extreme value distributions

    CERN Document Server

    Ahsanullah, Mohammad

    2016-01-01

    The aim of the book is to give a through account of the basic theory of extreme value distributions. The book cover a wide range of materials available to date. The central ideas and results of extreme value distributions are presented. The book rwill be useful o applied statisticians as well statisticians interrested to work in the area of extreme value distributions.vmonograph presents the central ideas and results of extreme value distributions.The monograph gives self-contained of theory and applications of extreme value distributions.

  17. Are BALQSOs extreme accretors?

    Science.gov (United States)

    Yuan, M. J.; Wills, B. J.

    2002-12-01

    Broad Absorption Line (BAL) QSOs are QSOs with massive absorbing outflows up to 0.2c. Two hypothesis have been suggested in the past about the nature of BALQSOs: Every QSO might have BAL outflow with some covering factor. BALQSOs are those which happen to have outflow along our line of sight. BALQSOs have intrinsically different physical properties than non-BALQSOs. Based on BALQSO's optical emission properties and a large set of correlations linking many general QSO emission line and continuum properties, it has been suggested that BALQSOs might accrete at near Eddington limit with abundant of fuel supplies. With new BALQSO Hβ region spectroscopic observation conducted at UKIRT and re-analysis of literature data for low and high redshift non-BALQSOs, We confirm that BALQSOs have extreme Fe II and [O III] emission line properties. Using results derived from the latest QSO Hβ region reverberation mapping, we calculated Eddington ratios (˙ {M}/˙ {M}Edd) for our BAL and non-BALQSOs. The Fe II and [O III] strengths are strongly correlated with Eddington ratios. Those correlations link Eddington ratio to a large set of general QSO properties through the Boroson & Green Eigenvector 1. We find that BALQSOs have Eddington ratios close to 1. However, all high redshift, high luminosity QSOs have rather high Eddington ratios. We argue that this is a side effect from selecting the brightest objects. In fact, our high redshift sample might constitute BALQSO's high Eddington ratio orientation parent population.

  18. Attribution of climate extreme events

    Science.gov (United States)

    Trenberth, Kevin E.; Fasullo, John T.; Shepherd, Theodore G.

    2015-08-01

    There is a tremendous desire to attribute causes to weather and climate events that is often challenging from a physical standpoint. Headlines attributing an event solely to either human-induced climate change or natural variability can be misleading when both are invariably in play. The conventional attribution framework struggles with dynamically driven extremes because of the small signal-to-noise ratios and often uncertain nature of the forced changes. Here, we suggest that a different framing is desirable, which asks why such extremes unfold the way they do. Specifically, we suggest that it is more useful to regard the extreme circulation regime or weather event as being largely unaffected by climate change, and question whether known changes in the climate system's thermodynamic state affected the impact of the particular event. Some examples briefly illustrated include 'snowmaggedon' in February 2010, superstorm Sandy in October 2012 and supertyphoon Haiyan in November 2013, and, in more detail, the Boulder floods of September 2013, all of which were influenced by high sea surface temperatures that had a discernible human component.

  19. How extreme is extreme hourly precipitation?

    Science.gov (United States)

    Papalexiou, Simon Michael; Dialynas, Yannis G.; Pappas, Christoforos

    2016-04-01

    The importance of accurate representation of precipitation at fine time scales (e.g., hourly), directly associated with flash flood events, is crucial in hydrological design and prediction. The upper part of a probability distribution, known as the distribution tail, determines the behavior of extreme events. In general, and loosely speaking, tails can be categorized in two families: the subexponential and the hyperexponential family, with the first generating more intense and more frequent extremes compared to the latter. In past studies, the focus has been mainly on daily precipitation, with the Gamma distribution being the most popular model. Here, we investigate the behaviour of tails of hourly precipitation by comparing the upper part of empirical distributions of thousands of records with three general types of tails corresponding to the Pareto, Lognormal, and Weibull distributions. Specifically, we use thousands of hourly rainfall records from all over the USA. The analysis indicates that heavier-tailed distributions describe better the observed hourly rainfall extremes in comparison to lighter tails. Traditional representations of the marginal distribution of hourly rainfall may significantly deviate from observed behaviours of extremes, with direct implications on hydroclimatic variables modelling and engineering design.

  20. Preconcentration of trace manganese from natural waters by complexation with dithiocarbamate and adsorption onto C18-solid phase extraction column for neutron activation analysis

    International Nuclear Information System (INIS)

    Sarmani, S.B.; Abdullah, M.P.; Bobaker, A.M.

    2004-01-01

    A method was developed for the preconcentration and separation of trace manganese from natural water samples by complexation with dithiocarbamate followed by adsorption onto C 18 -solid phase extraction column prior to irradiation. The Mn recovery was better than 99.8% without interference from iron(III) at 5 mg x l -1 , copper(II), zinc(II), aluminum(III) and cobalt(II) at 0.5 mg x l -1 and sodium(I), potassium(I), magnesium(II) and calcium(II) at 1 mg x l -1 . The separation factor was 100 and the detection limit was 0.01 μg x l -1 with good precision and accuracy with a relative error lower than 3%. The method was applied to the determination of Mn in tap, well, river and treated water samples. (author)

  1. On causality of extreme events

    Directory of Open Access Journals (Sweden)

    Massimiliano Zanin

    2016-06-01

    Full Text Available Multiple metrics have been developed to detect causality relations between data describing the elements constituting complex systems, all of them considering their evolution through time. Here we propose a metric able to detect causality within static data sets, by analysing how extreme events in one element correspond to the appearance of extreme events in a second one. The metric is able to detect non-linear causalities; to analyse both cross-sectional and longitudinal data sets; and to discriminate between real causalities and correlations caused by confounding factors. We validate the metric through synthetic data, dynamical and chaotic systems, and data representing the human brain activity in a cognitive task. We further show how the proposed metric is able to outperform classical causality metrics, provided non-linear relationships are present and large enough data sets are available.

  2. The personal dispositions of violent extremism

    Directory of Open Access Journals (Sweden)

    Davydov D.G.

    2017-04-01

    Full Text Available The paper presents the differences in the nature of extremism and radicalism, and the necessity of introducing the concept of "violent extremism." It is shown that the ideology is the explanation of extremist behavior, rather than its cause. The ideology of extremism often eclectic, contradictory and can easily be transformed by changing the object of hostility, depending on the situation. For the description of the psychological causes of extremism it is proposed to use the concept of personal disposition. Disposition is the preferred way to subjective interpretation of reality and reflects both the specific needs of a person as well the typical social situations where it realized and personal experience. Considered the following dispositions of violent extremism: the Cult of force and aggression, Intolerance, Out-group hostility Conventional coercion, Social pessimism and destructiveness, Mystical, Fighting and overcoming, Nihilism to law, Anti-subjectivism. It is proposed to use these dispositions as diagnostic criteria and for preventing and correcting.

  3. Christian Extremism as a Domestic Terror Threat

    Science.gov (United States)

    2011-05-19

    extremism with cultural relativism to universally deem extremist actions as justified.8 Religious extremism and conflict are not new. Conceivably, as...legitimized this practice, they forfeited their legitimacy and moral authority to govern.” Rudolph went on to state that his actions were to “embarrass and...funerals?7 Religion remains a significantly complex and controversial subject within any social culture . Like any social construct, religion is subject

  4. Extremism from the perspective of a system approach

    Directory of Open Access Journals (Sweden)

    Zinchenko, Yury P.

    2014-03-01

    Full Text Available Extremism is seen as a complex, multilevel, and multicomponent phenomenon. The problems of modern science in understanding extremism are revealed. The following bases of extremism as a system phenomenon are singled out: social factors, latent extremism, and extremist acts. It is demonstrated that a system approach makes it possible to shape a notion of a subject as a system, to identify patterns of the manifestations of the given phenomenon, and to translate them into concrete practices.

  5. Influence of the competition of anions (hydroxides, carbonates) on the complexation of trivalent lanthanides by natural organic matter: case of humic substances

    International Nuclear Information System (INIS)

    Kouhail, Yasmine

    2016-01-01

    The aim of this study is to acquire and refine complexation data for understanding the fate of lanthanides in the environment where the concentrations of organic matter are highly variable. This study is focusing on both the description and understanding of the interactions between the europium(III) and a Suwannee River fulvic acid (SRFA) as a representative of humic substances (HS), and the influence of major anions present in natural waters, i.e. hydroxides and carbonates ions, in these interactions. To understand the ternary systems Eu-OH-SRFA and EU-CO_3-SRFA, Eu-SRFA and EU-CO_3 binary systems are first investigated by time-resolved luminescence spectroscopy (TRLS) for wide ranges of pH, ionic strength, Eu(III), SRFA and CO_3 concentrations. This study shows that the structures of humic substances are influenced by the presence of Eu(III). Interaction constants are determined for the Eu-SRFA binary system and are used for the understanding of the EU-CO_3-SRFA ternary system. EU-CO_3-SRF A ternary complexes are highlighted by SLRT, and an interaction constant has also been proposed in the frame of the NICA-Donnan model. Variations in size of EuSRFA complexes as a function of europium and SRFA concentrations are presented, and the impact of these variations on NICA-Donnan parameters is investigated. The results of this work are challenging modeling concepts of metal-HS interactions at various HS concentrations, in particular for the consideration of electrostatic effects. (author) [fr

  6. Test fields cannot destroy extremal black holes

    International Nuclear Information System (INIS)

    Natário, José; Queimada, Leonel; Vicente, Rodrigo

    2016-01-01

    We prove that (possibly charged) test fields satisfying the null energy condition at the event horizon cannot overspin/overcharge extremal Kerr–Newman or Kerr–Newman–anti de Sitter black holes, that is, the weak cosmic censorship conjecture cannot be violated in the test field approximation. The argument relies on black hole thermodynamics (without assuming cosmic censorship), and does not depend on the precise nature of the fields. We also discuss generalizations of this result to other extremal black holes. (paper)

  7. [Injury mechanisms in extreme violence settings].

    Science.gov (United States)

    Arcaute-Velazquez, Fernando Federico; García-Núñez, Luis Manuel; Noyola-Vilallobos, Héctor Faustino; Espinoza-Mercado, Fernando; Rodríguez-Vega, Carlos Eynar

    2016-01-01

    Extreme violence events are consequence of current world-wide economic, political and social conditions. Injury patterns found among victims of extreme violence events are very complex, obeying several high-energy injury mechanisms. In this article, we present the basic concepts of trauma kinematics that regulate the clinical approach to victims of extreme violence events, in the hope that clinicians increase their theoretical armamentarium, and reflecting on obtaining better outcomes. Copyright © 2016. Published by Masson Doyma México S.A.

  8. Natural Patterns and Complex Architectures

    OpenAIRE

    Mallo Zurdo, Maria

    2013-01-01

    Análisis de los procesos de generación de formas naturales como las películas de jabón, los tejidos celulares, las moléculas de carbono y los radiolarios. Mostrando ejemplos arquitectónicos que utilizan las mismas leyes geométricas.

  9. Classifying Returns as Extreme

    DEFF Research Database (Denmark)

    Christiansen, Charlotte

    2014-01-01

    I consider extreme returns for the stock and bond markets of 14 EU countries using two classification schemes: One, the univariate classification scheme from the previous literature that classifies extreme returns for each market separately, and two, a novel multivariate classification scheme tha...

  10. Long term oscillations in Danish rainfall extremes

    DEFF Research Database (Denmark)

    Gregersen, Ida Bülow; Madsen, Henrik; Rosbjerg, Dan

    The frequent flooding of European cities within the last decade has motivated a vast number of studies, among others addressing the non-stationary behaviour of hydrological extremes driven by anthropogenic climate change. However, when considering future extremes it also becomes relevant to search...... for and understand natural variations on which the anthropogenic changes are imposed. This study identifies multi-decadal variations in six 137-years-long diurnal rainfall series from Denmark and southern Sweden, focusing on extremes with a reoccurrence level relevant for Danish drainage design. By means of a Peak...

  11. Extreme weather and climate events with ecological relevance: a review.

    Science.gov (United States)

    Ummenhofer, Caroline C; Meehl, Gerald A

    2017-06-19

    Robust evidence exists that certain extreme weather and climate events, especially daily temperature and precipitation extremes, have changed in regard to intensity and frequency over recent decades. These changes have been linked to human-induced climate change, while the degree to which climate change impacts an individual extreme climate event (ECE) is more difficult to quantify. Rapid progress in event attribution has recently been made through improved understanding of observed and simulated climate variability, methods for event attribution and advances in numerical modelling. Attribution for extreme temperature events is stronger compared with other event types, notably those related to the hydrological cycle. Recent advances in the understanding of ECEs, both in observations and their representation in state-of-the-art climate models, open new opportunities for assessing their effect on human and natural systems. Improved spatial resolution in global climate models and advances in statistical and dynamical downscaling now provide climatic information at appropriate spatial and temporal scales. Together with the continued development of Earth System Models that simulate biogeochemical cycles and interactions with the biosphere at increasing complexity, these make it possible to develop a mechanistic understanding of how ECEs affect biological processes, ecosystem functioning and adaptation capabilities. Limitations in the observational network, both for physical climate system parameters and even more so for long-term ecological monitoring, have hampered progress in understanding bio-physical interactions across a range of scales. New opportunities for assessing how ECEs modulate ecosystem structure and functioning arise from better scientific understanding of ECEs coupled with technological advances in observing systems and instrumentation.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events

  12. Computational data sciences for assessment and prediction of climate extremes

    Science.gov (United States)

    Ganguly, A. R.

    2011-12-01

    Climate extremes may be defined inclusively as severe weather events or large shifts in global or regional weather patterns which may be caused or exacerbated by natural climate variability or climate change. This area of research arguably represents one of the largest knowledge-gaps in climate science which is relevant for informing resource managers and policy makers. While physics-based climate models are essential in view of non-stationary and nonlinear dynamical processes, their current pace of uncertainty reduction may not be adequate for urgent stakeholder needs. The structure of the models may in some cases preclude reduction of uncertainty for critical processes at scales or for the extremes of interest. On the other hand, methods based on complex networks, extreme value statistics, machine learning, and space-time data mining, have demonstrated significant promise to improve scientific understanding and generate enhanced predictions. When combined with conceptual process understanding at multiple spatiotemporal scales and designed to handle massive data, interdisciplinary data science methods and algorithms may complement or supplement physics-based models. Specific examples from the prior literature and our ongoing work suggests how data-guided improvements may be possible, for example, in the context of ocean meteorology, climate oscillators, teleconnections, and atmospheric process understanding, which in turn can improve projections of regional climate, precipitation extremes and tropical cyclones in an useful and interpretable fashion. A community-wide effort is motivated to develop and adapt computational data science tools for translating climate model simulations to information relevant for adaptation and policy, as well as for improving our scientific understanding of climate extremes from both observed and model-simulated data.

  13. Seasonal Climate Extremes : Mechanism, Predictability and Responses to Global Warming

    NARCIS (Netherlands)

    Shongwe, M.E.

    2010-01-01

    Climate extremes are rarely occurring natural phenomena in the climate system. They often pose one of the greatest environmental threats to human and natural systems. Statistical methods are commonly used to investigate characteristics of climate extremes. The fitted statistical properties are often

  14. Fe- and Cu-complex formation with artificial ligands investigated by ultra-high resolution Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS: Implications for natural metal-organic complex studies

    Directory of Open Access Journals (Sweden)

    Hannelore Waska

    2016-07-01

    Full Text Available In recent years, electrospray-ionization mass spectrometry (ESI-MS has been increasingly used to complement the bulk determination of metal-ligand equilibria, for example via competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-ACSV. However, ESI-MS speciation analyses may be impacted by instrumental artefacts such as reduction reactions, fragmentation, and adduct formation at the ESI source, changes in the ionization efficiencies of the detected species in relation to sample matrix, and peak overlaps in response to increasing sample complexity. In our study, equilibria of the known artificial ligands citrate, ethylenediaminetetraacetic acid (EDTA, 1-nitroso-2-naphthol (NN, and salicylaldoxime (SA with iron (Fe and copper (Cu were investigated by ultra-high resolution ESI-MS, Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS, under a variety of sample matrix and ionization settings. The acquired mass spectra were compared with metal-ligand equilibrium data from the literature as well as an adapted speciation model. Overall, the mass spectra produced representative species mentioned in previous reports and predicted by the speciation calculations, such as Fe(Cit, Cu(Cit2, Fe(EDTA, Cu(EDTA, Fe(NN3, and Cu(SA2. The analyses furthermore revealed new species which had been hypothesized but not measured directly using other methods, for example ternary complexes of citrate with Fe and Cu, Cu(SA monomers, and the dimer Fe(SA2. Finally, parallel measurements of a Cu+SA calibration series and a Cu+SA+EDTA competition series indicated that FT-ICR-MS can produce linear responses and low detection limits analogous to those of ACSV. We propose that ultra-high resolution FT-ICR-MS can be used as a representative tool to study interactions of trace metals with artificial as well as natural, unknown ligands at the molecular level.

  15. Extremal surface barriers

    International Nuclear Information System (INIS)

    Engelhardt, Netta; Wall, Aron C.

    2014-01-01

    We present a generic condition for Lorentzian manifolds to have a barrier that limits the reach of boundary-anchored extremal surfaces of arbitrary dimension. We show that any surface with nonpositive extrinsic curvature is a barrier, in the sense that extremal surfaces cannot be continuously deformed past it. Furthermore, the outermost barrier surface has nonnegative extrinsic curvature. Under certain conditions, we show that the existence of trapped surfaces implies a barrier, and conversely. In the context of AdS/CFT, these barriers imply that it is impossible to reconstruct the entire bulk using extremal surfaces. We comment on the implications for the firewall controversy

  16. Evolution of the Petasis-Ferrier union/rearrangement tactic: construction of architecturally complex natural products possessing the ubiquitous cis-2,6-substituted tetrahydropyran structural element.

    Science.gov (United States)

    Smith, Amos B; Fox, Richard J; Razler, Thomas M

    2008-05-01

    The frequent low abundance of architecturally complex natural products possessing significant bioregulatory properties mandates the development of rapid, efficient, and stereocontrolled synthetic tactics, not only to provide access to the biologically rare target but also to enable elaboration of analogues for the development of new therapeutic agents with improved activities and/or pharmacokinetic properties. In this Account, the genesis and evolution of the Petasis-Ferrier union/rearrangement tactic, in the context of natural product total syntheses, is described. The reaction sequence comprises a powerful tactic for the construction of the 2,6- cis-substituted tetrahydropyran ring system, a ubiquitous structural element often found in complex natural products possessing significant bioactivities. The three-step sequence, developed in our laboratory, extends two independent methods introduced by Ferrier and Petasis and now comprises: condensation between a chiral, nonracemic beta-hydroxy acid and an aldehyde to furnish a dioxanone; carbonyl olefination; and Lewis-acid-induced rearrangement of the resultant enol acetal to generate the 2,6- cis-substituted tetrahydropyranone system in a highly stereocontrolled fashion. To demonstrate the envisioned versatility and robustness of the Petasis-Ferrier union/rearrangement tactic in complex molecule synthesis, we exploited the method as the cornerstone in our now successful total syntheses of (+)-phorboxazole A, (+)-zampanolide, (+)-dactylolide, (+)-spongistatins 1 and 2, (-)-kendomycin, (-)-clavosolide A, and most recently, (-)-okilactomycin. Although each target comprises a number of synthetic challenges, this Account focuses on the motivation, excitement, and frustrations associated with the evolution and implementation of the Petasis-Ferrier union/rearrangement tactic. For example, during our (+)-phorboxazole A endeavor, we recognized and exploited the inherent pseudo symmetry of the 2,6- cis

  17. Influence of the control system on wind turbine loads during power production in extreme turbulence: Structural reliability

    DEFF Research Database (Denmark)

    Abdallah, Imad; Natarajan, Anand; Sørensen, John Dalsgaard

    2016-01-01

    structural reliability are assessed when the extreme turbulence model is uncertain. The structural reliability is assessed for the wind turbine when three configurations of an industrial grade load alleviation control system of increasing complexity and performance are used. The load alleviation features......The wind energy industry is continuously researching better computational models of wind inflow and turbulence to predict extreme loading (the nature of randomness) and their corresponding probability of occurrence. Sophisticated load alleviation control systems are increasingly being designed...... and deployed to specifically reduce the adverse effects of extreme load events resulting in lighter structures. The main objective herein is to show that despite large uncertainty in the extreme turbulence models, advanced load alleviation control systems yield both a reduction in magnitude and scatter...

  18. Arctigenin, a natural compound, activates AMP-activated protein kinase via inhibition of mitochondria complex I and ameliorates metabolic disorders in ob/ob mice.

    Science.gov (United States)

    Huang, S-L; Yu, R-T; Gong, J; Feng, Y; Dai, Y-L; Hu, F; Hu, Y-H; Tao, Y-D; Leng, Y

    2012-05-01

    Arctigenin is a natural compound that had never been previously demonstrated to have a glucose-lowering effect. Here it was found to activate AMP-activated protein kinase (AMPK), and the mechanism by which this occurred, as well as the effects on glucose and lipid metabolism were investigated. 2-Deoxyglucose uptake and AMPK phosphorylation were examined in L6 myotubes and isolated skeletal muscle. Gluconeogenesis and lipid synthesis were evaluated in rat primary hepatocytes. The acute and chronic effects of arctigenin on metabolic abnormalities were observed in C57BL/6J and ob/ob mice. Changes in mitochondrial membrane potential were measured using the J-aggregate-forming dye, JC-1. Analysis of respiration of L6 myotubes or isolated mitochondria was conducted in a channel oxygen system. Arctigenin increased AMPK phosphorylation and stimulated glucose uptake in L6 myotubes and isolated skeletal muscles. In primary hepatocytes, it decreased gluconeogenesis and lipid synthesis. The enhancement of glucose uptake and suppression of hepatic gluconeogenesis and lipid synthesis by arctigenin were prevented by blockade of AMPK activation. The respiration of L6 myotubes or isolated mitochondria was inhibited by arctigenin with a specific effect on respiratory complex I. A single oral dose of arctigenin reduced gluconeogenesis in C57BL/6J mice. Chronic oral administration of arctigenin lowered blood glucose and improved lipid metabolism in ob/ob mice. This study demonstrates a new role for arctigenin as a potent indirect activator of AMPK via inhibition of respiratory complex I, with beneficial effects on metabolic disorders in ob/ob mice. This highlights the potential value of arctigenin as a possible treatment of type 2 diabetes.

  19. Comparison of a traditional with a new approach based on Graph Theory to vulnerability assessment to natural hazards: a study case on a socio-economic complex system

    Science.gov (United States)

    Arosio, Marcello; Martina, Mario L. V.

    2017-04-01

    The emergent behaviour of the contemporary complex, socio-technical and interconnected society makes the collective risk greater than the sum of the parts and this requires a holistic, systematic and integrated approach. Although there have been major improvements in recent years, there are still some limitation in term of a holistic approach that is able to include the emergent value hidden in the connections between exposed elements and the interactions between the different spheres of the multi-hazards, vulnerability, exposure and resilience. To deal with these challenges it is necessary to consider the connections between the exposed elements (e.g. populations, schools, hospital, etc.) and to quantify the relative importance of the elements and their interconnections (e.g. the need of injured people to go to hospital or children to school). In a system (e.g. road, hospital and ecological network, etc.), or in a System of System (e.g. socio-technical urban service), there are critical elements that, beyond the intrinsic vulnerability, can be characterized by greater or lower vulnerability because of their physical, geographical, cyber or logical connections. To this aim, we propose in this study a comparative analysis between traditional reductionist approach and a new holistic approach to vulnerability assessment to natural hazards. The analysis considers a study case of a socio-economic complex system through an innovative approach based on the properties of graph G=(N,L). A graph consists of two sets N (nodes) and L (links): the nodes represent the single exposed elements (physical, social, environmental, etc.) to a hazard, while the links (or connections) represent the interaction between the elements. The final goal is to illustrate an application of this innovative approach of integrated collective vulnerability assessment.

  20. Towards a unified study of extreme events using universality concepts and transdisciplinary analysis methods

    Science.gov (United States)

    Balasis, George; Donner, Reik V.; Donges, Jonathan F.; Radebach, Alexander; Eftaxias, Konstantinos; Kurths, Jürgen

    2013-04-01

    The dynamics of many complex systems is characterized by the same universal principles. In particular, systems which are otherwise quite different in nature show striking similarities in their behavior near tipping points (bifurcations, phase transitions, sudden regime shifts) and associated extreme events. Such critical phenomena are frequently found in diverse fields such as climate, seismology, or financial markets. Notably, the observed similarities include a high degree of organization, persistent behavior, and accelerated energy release, which are common to (among others) phenomena related to geomagnetic variability of the terrestrial magnetosphere (intense magnetic storms), seismic activity (electromagnetic emissions prior to earthquakes), solar-terrestrial physics (solar flares), neurophysiology (epileptic seizures), and socioeconomic systems (stock market crashes). It is an open question whether the spatial and temporal complexity associated with extreme events arises from the system's structural organization (geometry) or from the chaotic behavior inherent to the nonlinear equations governing the dynamics of these phenomena. On the one hand, the presence of scaling laws associated with earthquakes and geomagnetic disturbances suggests understanding these events as generalized phase transitions similar to nucleation and critical phenomena in thermal and magnetic systems. On the other hand, because of the structural organization of the systems (e.g., as complex networks) the associated spatial geometry and/or topology of interactions plays a fundamental role in the emergence of extreme events. Here, a few aspects of the interplay between geometry and dynamics (critical phase transitions) that could result in the emergence of extreme events, which is an open problem, will be discussed.

  1. Complex motivated behaviors for natural rewards following a binge-like regimen of morphine administration: mixed phenotypes of anhedonia and craving after short-term withdrawal

    Directory of Open Access Journals (Sweden)

    Yunjing eBai

    2014-02-01

    Full Text Available The anhedonia-like behaviors following about one-week withdrawal from morphine were examined in the present study. Male rats were pretreated with either a binge-like morphine paradigm or daily saline injection for 5 days. Three types of natural reward were used, food reward (2.5%, 4%, 15%, 30%, 40% and 60% sucrose solutions, social reward (male rat and sexual reward (estrous female rat. For each type of natural stimulus, consummatory behavior and motivational behaviors under varied testing conditions were investigated. The results showed that the morphine-treated rats significantly reduced their consumption of 2.5% sucrose solution during the 1-hour consumption testing and their operant responding for 15%, 30% and 40% sucrose solutions under a fixed ratio 1 (FR1 schedule. However, performance under a progressive ratio (PR schedule increased in morphine-treated rats reinforced with 60% sucrose solution, but not in those reinforced with sucrose concentrations lower than 60%. Pretreatment with morphine significantly decreased the male rats’ ejaculation frequency during the 1-hour copulation testing, and impaired the maintenance of appetitive motivations to sexual and social stimuli under a free-approach condition. Moreover, the morphine-treated rats demonstrated a diminished motivation to approach social stimulus in the effort-based appetitive behavior test but showed a remarkable increase in motivation to approach sexual stimulus in the risky appetitive behavior test. These results demonstrated some complex motivated behaviors following about one week of morphine withdrawal: (1 The anhedonia-like behavior was consistently found in animals withdrawn from morphine. However, for a given reward, there was often a dissociation of the consummatory behaviors from the motivational behaviors, and whether the consummatory or the motivational anhedonia-like behaviors could be discovered heavily depended on the type and magnitude of the reward and the type

  2. Statistics of Extremes

    KAUST Repository

    Davison, Anthony C.; Huser, Raphaë l

    2015-01-01

    Statistics of extremes concerns inference for rare events. Often the events have never yet been observed, and their probabilities must therefore be estimated by extrapolation of tail models fitted to available data. Because data concerning the event

  3. Analysis of extreme events

    CSIR Research Space (South Africa)

    Khuluse, S

    2009-04-01

    Full Text Available ) determination of the distribution of the damage and (iii) preparation of products that enable prediction of future risk events. The methodology provided by extreme value theory can also be a powerful tool in risk analysis...

  4. Acute lower extremity ischaemia

    African Journals Online (AJOL)

    Acute lower extremity ischaemia. Acute lower limb ischaemia is a surgical emergency. ... is ~1.5 cases per 10 000 persons per year. Acute ischaemia ... Table 2. Clinical features discriminating embolic from thrombotic ALEXI. Clinical features.

  5. Stability of engineered nanomaterials in complex aqueous matrices: Settling behaviour of CeO{sub 2} nanoparticles in natural surface waters

    Energy Technology Data Exchange (ETDEWEB)

    Van Koetsem, Frederik, E-mail: Frederik.VanKoetsem@UGent.be [Laboratory of Analytical Chemistry and Applied Ecochemistry, Department of Applied Analytical and Physical Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, Ghent (Belgium); Verstraete, Simon [Laboratory of Analytical Chemistry and Applied Ecochemistry, Department of Applied Analytical and Physical Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, Ghent (Belgium); Van der Meeren, Paul [Particle and Interfacial Technology Group, Department of Applied Analytical and Physical Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, Ghent (Belgium); Du Laing, Gijs, E-mail: Gijs.DuLaing@UGent.be [Laboratory of Analytical Chemistry and Applied Ecochemistry, Department of Applied Analytical and Physical Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, Ghent (Belgium)

    2015-10-15

    The stability of engineered nanoparticles (ENPs) in complex aqueous matrices is a key determinant of their fate and potential toxicity towards the aquatic environment and human health. Metal oxide nanoparticles, such as CeO{sub 2} ENPs, are increasingly being incorporated into a wide range of industrial and commercial applications, which will undoubtedly result in their (unintentional) release into the environment. Hereby, the behaviour and fate of CeO{sub 2} ENPs could potentially serve as model for other nanoparticles that possess similar characteristics. The present study examined the stability and settling of CeO{sub 2} ENPs (7.3±1.4 nm) as well as Ce{sup 3+} ions in 10 distinct natural surface waters during 7 d, under stagnant and isothermal experimental conditions. Natural water samples were collected throughout Flanders (Belgium) and were thoroughly characterized. For the majority of the surface waters, a substantial depletion (>95%) of the initially added CeO{sub 2} ENPs was observed just below the liquid surface of the water samples after 7 d. In all cases, the reduction was considerably higher for CeO{sub 2} ENPs than for Ce{sup 3+} ions (<68%). A first-order kinetics model was able to describe the observed time-dependant removal of both CeO{sub 2} ENPs (R{sup 2}≥0.998) and Ce{sup 3+} ions (R{sup 2}≥0.812) from the water column, at least in case notable sedimentation occurred over time. Solution-pH appeared to be a prime parameter governing nanoparticle colloidal stability. Moreover, the suspended solids (TSS) content also seemed to be an important factor affecting the settling rate and residual fraction of CeO{sub 2} ENPs as well as Ce{sup 3+} ions in natural surface waters. Correlation results also suggest potential association and co-precipitation of CeO{sub 2} ENPs with aluminium- and iron-containing natural colloidal material. The CeO{sub 2} ENPs remained stable in dispersion in surface water characterized by a low pH, ionic strength (IS), and

  6. Extreme Weather and Climate: Workshop Report

    Science.gov (United States)

    Sobel, Adam; Camargo, Suzana; Debucquoy, Wim; Deodatis, George; Gerrard, Michael; Hall, Timothy; Hallman, Robert; Keenan, Jesse; Lall, Upmanu; Levy, Marc; hide

    2016-01-01

    Extreme events are the aspects of climate to which human society is most sensitive. Due to both their severity and their rarity, extreme events can challenge the capacity of physical, social, economic and political infrastructures, turning natural events into human disasters. Yet, because they are low frequency events, the science of extreme events is very challenging. Among the challenges is the difficulty of connecting extreme events to longer-term, large-scale variability and trends in the climate system, including anthropogenic climate change. How can we best quantify the risks posed by extreme weather events, both in the current climate and in the warmer and different climates to come? How can we better predict them? What can we do to reduce the harm done by such events? In response to these questions, the Initiative on Extreme Weather and Climate has been created at Columbia University in New York City (extreme weather.columbia.edu). This Initiative is a University-wide activity focused on understanding the risks to human life, property, infrastructure, communities, institutions, ecosystems, and landscapes from extreme weather events, both in the present and future climates, and on developing solutions to mitigate those risks. In May 2015,the Initiative held its first science workshop, entitled Extreme Weather and Climate: Hazards, Impacts, Actions. The purpose of the workshop was to define the scope of the Initiative and tremendously broad intellectual footprint of the topic indicated by the titles of the presentations (see Table 1). The intent of the workshop was to stimulate thought across disciplinary lines by juxtaposing talks whose subjects differed dramatically. Each session concluded with question and answer panel sessions. Approximately, 150 people were in attendance throughout the day. Below is a brief synopsis of each presentation. The synopses collectively reflect the variety and richness of the emerging extreme event research agenda.

  7. Possible future changes in extreme events over Northern Eurasia

    Science.gov (United States)

    Monier, Erwan; Sokolov, Andrei; Scott, Jeffery

    2013-04-01

    In this study, we investigate possible future climate change over Northern Eurasia and its impact on extreme events. Northern Eurasia is a major player in the global carbon budget because of boreal forests and peatlands. Circumpolar boreal forests alone contain more than five times the amount of carbon of temperate forests and almost double the amount of carbon of the world's tropical forests. Furthermore, severe permafrost degradation associated with climate change could result in peatlands releasing large amounts of carbon dioxide and methane. Meanwhile, changes in the frequency and magnitude of extreme events, such as extreme precipitation, heat waves or frost days are likely to have substantial impacts on Northern Eurasia ecosystems. For this reason, it is very important to quantify the possible climate change over Northern Eurasia under different emissions scenarios, while accounting for the uncertainty in the climate response and changes in extreme events. For several decades, the Massachusetts Institute of Technology (MIT) Joint Program on the Science and Policy of Global Change has been investigating uncertainty in climate change using the MIT Integrated Global System Model (IGSM) framework, an integrated assessment model that couples an earth system model of intermediate complexity (with a 2D zonal-mean atmosphere) to a human activity model. In this study, regional change is investigated using the MIT IGSM-CAM framework that links the IGSM to the National Center for Atmospheric Research (NCAR) Community Atmosphere Model (CAM). New modules were developed and implemented in CAM to allow climate parameters to be changed to match those of the IGSM. The simulations presented in this paper were carried out for two emission scenarios, a "business as usual" scenario and a 660 ppm of CO2-equivalent stabilization, which are similar to, respectively, the Representative Concentration Pathways RCP8.5 and RCP4.5 scenarios. Values of climate sensitivity and net aerosol

  8. Asynchronous schemes for CFD at extreme scales

    Science.gov (United States)

    Konduri, Aditya; Donzis, Diego

    2013-11-01

    Recent advances in computing hardware and software have made simulations an indispensable research tool in understanding fluid flow phenomena in complex conditions at great detail. Due to the nonlinear nature of the governing NS equations, simulations of high Re turbulent flows are computationally very expensive and demand for extreme levels of parallelism. Current large simulations are being done on hundreds of thousands of processing elements (PEs). Benchmarks from these simulations show that communication between PEs take a substantial amount of time, overwhelming the compute time, resulting in substantial waste in compute cycles as PEs remain idle. We investigate a novel approach based on widely used finite-difference schemes in which computations are carried out asynchronously, i.e. synchronization of data among PEs is not enforced and computations proceed regardless of the status of messages. This drastically reduces PE idle time and results in much larger computation rates. We show that while these schemes remain stable, their accuracy is significantly affected. We present new schemes that maintain accuracy under asynchronous conditions and provide a viable path towards exascale computing. Performance of these schemes will be shown for simple models like Burgers' equation.

  9. Extreme Programming: Maestro Style

    Science.gov (United States)

    Norris, Jeffrey; Fox, Jason; Rabe, Kenneth; Shu, I-Hsiang; Powell, Mark

    2009-01-01

    "Extreme Programming: Maestro Style" is the name of a computer programming methodology that has evolved as a custom version of a methodology, called extreme programming that has been practiced in the software industry since the late 1990s. The name of this version reflects its origin in the work of the Maestro team at NASA's Jet Propulsion Laboratory that develops software for Mars exploration missions. Extreme programming is oriented toward agile development of software resting on values of simplicity, communication, testing, and aggressiveness. Extreme programming involves use of methods of rapidly building and disseminating institutional knowledge among members of a computer-programming team to give all the members a shared view that matches the view of the customers for whom the software system is to be developed. Extreme programming includes frequent planning by programmers in collaboration with customers, continually examining and rewriting code in striving for the simplest workable software designs, a system metaphor (basically, an abstraction of the system that provides easy-to-remember software-naming conventions and insight into the architecture of the system), programmers working in pairs, adherence to a set of coding standards, collaboration of customers and programmers, frequent verbal communication, frequent releases of software in small increments of development, repeated testing of the developmental software by both programmers and customers, and continuous interaction between the team and the customers. The environment in which the Maestro team works requires the team to quickly adapt to changing needs of its customers. In addition, the team cannot afford to accept unnecessary development risk. Extreme programming enables the Maestro team to remain agile and provide high-quality software and service to its customers. However, several factors in the Maestro environment have made it necessary to modify some of the conventional extreme

  10. Extreme meteorological conditions

    International Nuclear Information System (INIS)

    Altinger de Schwarzkopf, M.L.

    1983-01-01

    Different meteorological variables which may reach significant extreme values, such as the windspeed and, in particular, its occurrence through tornadoes and hurricanes that necesarily incide and wich must be taken into account at the time of nuclear power plants' installation, are analyzed. For this kind of study, it is necessary to determine the basic phenomenum of design. Two criteria are applied to define the basic values of design for extreme meteorological variables. The first one determines the expected extreme value: it is obtained from analyzing the recurence of the phenomenum in a convened period of time, wich may be generally of 50 years. The second one determines the extreme value of low probability, taking into account the nuclear power plant's operating life -f.ex. 25 years- and considering, during said lapse, the occurrence probabilities of extreme meteorological phenomena. The values may be determined either by the deterministic method, which is based on the acknowledgement of the fundamental physical characteristics of the phenomena or by the probabilistic method, that aims to the analysis of historical statistical data. Brief comments are made on the subject in relation to the Argentine Republic area. (R.J.S.) [es

  11. To the limit of extreme malnutrition

    DEFF Research Database (Denmark)

    Frølich, Jacob; Buskbjerg, Camilla Viola; Støving, Rene K

    2016-01-01

    Extreme malnutrition with body mass index (BMI) as low as 10 kg/m(2) is not uncommon in anorexia nervosa, with survival enabled through complex metabolic adaptations. In contrast, outcomes from hunger strikes and famines are usually fatal after weight loss to about 40% below expected body weight...... malnutrition has not previously been reported. The present case emphasizes the importance of adherence...

  12. Extremely deformable structures

    CERN Document Server

    2015-01-01

    Recently, a new research stimulus has derived from the observation that soft structures, such as biological systems, but also rubber and gel, may work in a post critical regime, where elastic elements are subject to extreme deformations, though still exhibiting excellent mechanical performances. This is the realm of ‘extreme mechanics’, to which this book is addressed. The possibility of exploiting highly deformable structures opens new and unexpected technological possibilities. In particular, the challenge is the design of deformable and bi-stable mechanisms which can reach superior mechanical performances and can have a strong impact on several high-tech applications, including stretchable electronics, nanotube serpentines, deployable structures for aerospace engineering, cable deployment in the ocean, but also sensors and flexible actuators and vibration absorbers. Readers are introduced to a variety of interrelated topics involving the mechanics of extremely deformable structures, with emphasis on ...

  13. Statistics of Extremes

    KAUST Repository

    Davison, Anthony C.

    2015-04-10

    Statistics of extremes concerns inference for rare events. Often the events have never yet been observed, and their probabilities must therefore be estimated by extrapolation of tail models fitted to available data. Because data concerning the event of interest may be very limited, efficient methods of inference play an important role. This article reviews this domain, emphasizing current research topics. We first sketch the classical theory of extremes for maxima and threshold exceedances of stationary series. We then review multivariate theory, distinguishing asymptotic independence and dependence models, followed by a description of models for spatial and spatiotemporal extreme events. Finally, we discuss inference and describe two applications. Animations illustrate some of the main ideas. © 2015 by Annual Reviews. All rights reserved.

  14. Adventure and Extreme Sports.

    Science.gov (United States)

    Gomez, Andrew Thomas; Rao, Ashwin

    2016-03-01

    Adventure and extreme sports often involve unpredictable and inhospitable environments, high velocities, and stunts. These activities vary widely and include sports like BASE jumping, snowboarding, kayaking, and surfing. Increasing interest and participation in adventure and extreme sports warrants understanding by clinicians to facilitate prevention, identification, and treatment of injuries unique to each sport. This article covers alpine skiing and snowboarding, skateboarding, surfing, bungee jumping, BASE jumping, and whitewater sports with emphasis on epidemiology, demographics, general injury mechanisms, specific injuries, chronic injuries, fatality data, and prevention. Overall, most injuries are related to overuse, trauma, and environmental or microbial exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Extremal graph theory

    CERN Document Server

    Bollobas, Bela

    2004-01-01

    The ever-expanding field of extremal graph theory encompasses a diverse array of problem-solving methods, including applications to economics, computer science, and optimization theory. This volume, based on a series of lectures delivered to graduate students at the University of Cambridge, presents a concise yet comprehensive treatment of extremal graph theory.Unlike most graph theory treatises, this text features complete proofs for almost all of its results. Further insights into theory are provided by the numerous exercises of varying degrees of difficulty that accompany each chapter. A

  16. Extremes in random fields a theory and its applications

    CERN Document Server

    Yakir, Benjamin

    2013-01-01

    Presents a useful new technique for analyzing the extreme-value behaviour of random fields Modern science typically involves the analysis of increasingly complex data. The extreme values that emerge in the statistical analysis of complex data are often of particular interest. This book focuses on the analytical approximations of the statistical significance of extreme values. Several relatively complex applications of the technique to problems that emerge in practical situations are presented.  All the examples are difficult to analyze using classical methods, and as a result, the author pr

  17. Nature, geochemistry and petrogenesis of the syn-tectonic Amspoort suite (Pan-African Boundary Igneous Complex, Kaoko Belt, NW Namibia)

    Science.gov (United States)

    Janousek, Vojtech; Konopasek, Jiri; Ulrich, Stanislav

    2010-05-01

    Crucial information on the Neoproterozoic-Cambrian amalgamation of Western Gondwana is provided by studies of the large Pan-African collisional belt in central-northern Namibia. This so-called Damara Orogen (Miller, 1983) can be subdivided into two branches, the SW-NE trending Damara Belt and a roughly perpendicular, NNW-SSE trending Kaoko Belt further north. The Kaoko Belt consists of two principal crustal units. The easterly part has a Congo Craton affinity (a basement built mostly by ≥ 1.5 Ga granitic gneisses with Neoproterozoic metasedimentary cover), whereas the westerly Coastal Terrane consists of Neoproterozoic (c.850-650 Ma) metapsammites and minor metabasic bodies; no exposures of the basement were found. The at least 180 km long, NNW-SSE trending suture between both units was intruded by numerous syn-tectonic magmatic bodies with ages spanning the interval 580-550 Ma (Seth et al., 1998; Kröner et al., 2004) designated as the Boundary Igneous Complex by Konopásek et al. (2008). The most typical representatives of this syn-collision igneous association are c.550 Ma old K-feldspar-phyric, Bt ± Cam granites-granodiorites of the Amspoort suite, with minor Cpx gabbro and rare two-pyroxene dolerite bodies. The petrological character, whole-rock geochemistry and Sr-Nd isotopic signatures of the scarce Opx-Cpx-Bt dolerites indicate an origin from a CHUR-like mantle-derived melts (87Sr/86Sr550 ~ 0.7045, ɛNd550 ~ 0) modified by extensive (?Ol-) Cpx fractionation. The rest of the suite is interpreted as a product of a high-temperature anatexis of a heterogeneous lower crust, built mainly by immature metapsammites - rich in arc-derived detritus - with minor metabasite and intermediate metaigneous bodies. The most likely source appears to be the anatectic Coastal Terrane gneisses. Yet, partial melting of the so far little constrained Congo Craton cover, if formed by immature and youthful detritus unrelated to the basement, cannot be discounted. In any case, the

  18. Total synthesis and related studies of large, strained, and bioactive natural products

    Science.gov (United States)

    HIRAMA, Masahiro

    2016-01-01

    Our chemical syntheses and related scientific investigations of natural products with complex architectures and powerful biological activities are described, focusing on the very large 3 nm-long polycyclic ethers called the ciguatoxins, highly strained and labile chromoprotein antitumor antibiotics featuring nine-membered enediyne cores, and extremely potent anthelmintic macrolides called the avermectins. PMID:27725470

  19. Functional proteomic of Matrix Metallo-proteinases (MMP) dedicated to the detection of active forms of MMP in complex proteome; Proteomique fonctionnelle dediee aux Metalloproteases Matricelles (MMPs): developpement d'une methode extremement sensible permettant la detection des formes actives des MMPs dans des proteomes complexes

    Energy Technology Data Exchange (ETDEWEB)

    David, A

    2007-07-15

    The Matrix Metallo-proteinases (M.M.P.) represent a family of Zinc dependent extracellular proteinases able to cleave collectively all the proteins constituting the extracellular matrix. Currently, 23 human M.M.P. have been identified and are characterized by their sequence in amino-acids and their highly conserved 3 D structure. These enzymes are expressed constitutively during the tissue remodeling process. Their over-expression in various diseases tightly related to inflammatory processes (arthritis, emphysema, cancer) described M.M.P. as choice therapeutic targets. However, as the tissue remodeling implicates modification of cellular contacts, M.M.P. appear currently as proteins involved in signalling pathways. Recent works demonstrating that M.M.P. are able to cleave substrates, which are different than proteins constituting the extracellular matrix, reinforce this vision. In order to identify the individual role and the protein expression level of M.M.P. in pathological context, we developed a new technique of functional proteomics dedicated to the detection of active forms of M.M.P. in tumour samples. This technique relied on the development of a new photoaffinity probe, based on the structure of a potent phosphinic inhibitor of M.M.P., allowing targeting and isolating active forms of M.M.P. by photoaffinity labelling. Furthermore, as the new developed probe incorporated a radioactive element, photoaffinity labelling permitted to radiolabel the targeted proteins. This probe demonstrated in vitro its remarkable ability to covalently modify the h M.M.P.-12, with a singular cross-linking yield, determined at 42 %, displaying an extremely sensitive detection (2.5 fmoles of h M.M.P.-12). When added to complex proteome, the photoaffinity probe presents the same sensibility of detection for the h M.M.P.-12 (5 fmoles); importantly, in this case, h M.M.P.-12 represents only 0.001 % of the totality of the proteins present in the sample. Moreover, this technique allows

  20. Functional proteomic of Matrix Metallo-proteinases (MMP) dedicated to the detection of active forms of MMP in complex proteome; Proteomique fonctionnelle dediee aux Metalloproteases Matricelles (MMPs): developpement d'une methode extremement sensible permettant la detection des formes actives des MMPs dans des proteomes complexes

    Energy Technology Data Exchange (ETDEWEB)

    David, A

    2007-07-15

    The Matrix Metallo-proteinases (M.M.P.) represent a family of Zinc dependent extracellular proteinases able to cleave collectively all the proteins constituting the extracellular matrix. Currently, 23 human M.M.P. have been identified and are characterized by their sequence in amino-acids and their highly conserved 3 D structure. These enzymes are expressed constitutively during the tissue remodeling process. Their over-expression in various diseases tightly related to inflammatory processes (arthritis, emphysema, cancer) described M.M.P. as choice therapeutic targets. However, as the tissue remodeling implicates modification of cellular contacts, M.M.P. appear currently as proteins involved in signalling pathways. Recent works demonstrating that M.M.P. are able to cleave substrates, which are different than proteins constituting the extracellular matrix, reinforce this vision. In order to identify the individual role and the protein expression level of M.M.P. in pathological context, we developed a new technique of functional proteomics dedicated to the detection of active forms of M.M.P. in tumour samples. This technique relied on the development of a new photoaffinity probe, based on the structure of a potent phosphinic inhibitor of M.M.P., allowing targeting and isolating active forms of M.M.P. by photoaffinity labelling. Furthermore, as the new developed probe incorporated a radioactive element, photoaffinity labelling permitted to radiolabel the targeted proteins. This probe demonstrated in vitro its remarkable ability to covalently modify the h M.M.P.-12, with a singular cross-linking yield, determined at 42 %, displaying an extremely sensitive detection (2.5 fmoles of h M.M.P.-12). When added to complex proteome, the photoaffinity probe presents the same sensibility of detection for the h M.M.P.-12 (5 fmoles); importantly, in this case, h M.M.P.-12 represents only 0.001 % of the totality of the proteins present in the sample. Moreover, this technique allows

  1. Stellar extreme ultraviolet astronomy

    International Nuclear Information System (INIS)

    Cash, W.C. Jr.

    1978-01-01

    The design, calibration, and launch of a rocket-borne imaging telescope for extreme ultraviolet astronomy are described. The telescope, which employed diamond-turned grazing incidence optics and a ranicon detector, was launched November 19, 1976, from the White Sands Missile Range. The telescope performed well and returned data on several potential stellar sources of extreme ultraviolet radiation. Upper limits ten to twenty times more sensitive than previously available were obtained for the extreme ultraviolet flux from the white dwarf Sirius B. These limits fall a factor of seven below the flux predicted for the star and demonstrate that the temperature of Sirius B is not 32,000 K as previously measured, but is below 30,000 K. The new upper limits also rule out the photosphere of the white dwarf as the source of the recently reported soft x-rays from Sirius. Two other white dwarf stars, Feige 24 and G191-B2B, were observed. Upper limits on the flux at 300 A were interpreted as lower limits on the interstellar hydrogen column densities to these stars. The lower limits indicate interstellar hydrogen densitites of greater than .02 cm -3 . Four nearby stars (Sirius, Procyon, Capella, and Mirzam) were observed in a search for intense low temperature coronae or extended chromospheres. No extreme ultraviolet radiation from these stars was detected, and upper limits to their coronal emisson measures are derived

  2. Extremity x-ray

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003461.htm Extremity x-ray To use the sharing features on this page, ... in the body Risks There is low-level radiation exposure. X-rays are monitored and regulated to provide the ...

  3. Extremity perfusion for sarcoma

    NARCIS (Netherlands)

    Hoekstra, Harald Joan

    2008-01-01

    For more than 50 years, the technique of extremity perfusion has been explored in the limb salvage treatment of local, recurrent, and multifocal sarcomas. The "discovery" of tumor necrosis factor-or. in combination with melphalan was a real breakthrough in the treatment of primarily irresectable

  4. Statistics of Local Extremes

    DEFF Research Database (Denmark)

    Larsen, Gunner Chr.; Bierbooms, W.; Hansen, Kurt Schaldemose

    2003-01-01

    . A theoretical expression for the probability density function associated with local extremes of a stochasticprocess is presented. The expression is basically based on the lower four statistical moments and a bandwidth parameter. The theoretical expression is subsequently verified by comparison with simulated...

  5. Extreme Weather Events and Climate Change Attribution

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Katherine [National Academy of Sciences, Washington, DC (United States)

    2016-03-31

    A report from the National Academies of Sciences, Engineering, and Medicine concludes it is now possible to estimate the influence of climate change on some types of extreme events. The science of extreme event attribution has advanced rapidly in recent years, giving new insight to the ways that human-caused climate change can influence the magnitude or frequency of some extreme weather events. This report examines the current state of science of extreme weather attribution, and identifies ways to move the science forward to improve attribution capabilities. Confidence is strongest in attributing types of extreme events that are influenced by climate change through a well-understood physical mechanism, such as, the more frequent heat waves that are closely connected to human-caused global temperature increases, the report finds. Confidence is lower for other types of events, such as hurricanes, whose relationship to climate change is more complex and less understood at present. For any extreme event, the results of attribution studies hinge on how questions about the event's causes are posed, and on the data, modeling approaches, and statistical tools chosen for the analysis.

  6. Weather extremes could affect agriculture

    Science.gov (United States)

    Balcerak, Ernie

    2012-05-01

    As Earth's climate warms, agricultural producers will need to adapt. Changes, especially increases in extreme events, are already having an impact on food production, according to speakers at a 1 May session on agriculture and food security at the AGU Science Policy Conference. Christopher Field, director of the Department of Global Ecology at the Carnegie Institution for Science of Washington, D. C., pointed out the complex factors that come into play in understanding food security, including spatially varying controls and stresses, incomplete models, and the potential for threshold responses. Factors that are likely to cause problems include increasing population; increasing preference for meat, which needs more land and energy inputs to produce; climate change; and increasing use of agricultural lands for biomass energy.

  7. Rhabdomyosarcoma of the extremity

    International Nuclear Information System (INIS)

    Rao, Bhaskar N

    1997-01-01

    Rhabdomyosarcoma is the most common soft tissue sarcoma accounting for almost 55%. These tumors arise from unsegmented mesoderm or primitive mesenchyma, which have the capacity to differentiate into muscle. Less than 5% occur in the first year of life. Extremity rhabdomyosarcoma are mainly seen in the adolescent years. The most common histologic subtype is the alveolar variant. Other characteristics of extremity rhabdomyosarcoma include a predilection for lymph node metastasis, a high local failure, and a relatively low survival rate. They often present as slow painless masses; however, lesions in the hand and foot often present as painful masses and imaging studies may show invasion of the bone. Initial diagnostic approaches include needle biopsy or incisional biopsy for larger lesions. Excisional biopsy is indicated preferably for lesions less than 2.5 cm. following this in most instances therapy is initiated with multi agent chemotherapy depending upon response, the next modality may be either surgery with intent to cure or radiation therapy. Amputation of an extremity for local control is not considered in most instances. Prognostic factors that have been determined over the years to be of significance by multi variant analysis have included age, tumor size, invasiveness, presence of either nodal or distant metastasis, and complete excision whenever feasible, with supplemental radiation therapy for local control

  8. Insertion sequences enrichment in extreme Red sea brine pool vent

    KAUST Repository

    Elbehery, Ali H. A.; Aziz, Ramy K.; Siam, Rania

    2016-01-01

    Mobile genetic elements are major agents of genome diversification and evolution. Limited studies addressed their characteristics, including abundance, and role in extreme habitats. One of the rare natural habitats exposed to multiple

  9. Ecosystem responses to extreme natural events: impacts of three sequential hurricanes in fall 1999 on sediment quality and condition of benthic fauna in the Neuse River Estuary, North Carolina.

    Science.gov (United States)

    Balthis, W Leonard; Hyland, Jeffrey L; Bearden, Daniel W

    2006-08-01

    A study was conducted in November 1999 to assess sediment quality and condition of benthic fauna in the Neuse River Estuary (NRE), North Carolina, USA, following the passage of three Atlantic hurricanes during the two months prior. Samples for analysis of macroinfauna (>0.5 mm sieve size), chemical contamination of sediments, and other abiotic environmental variables (salinity, dissolved oxygen, pH, depth, sediment granulometry) were collected at 20 sites from the mouth of the Neuse River at Pamlico Sound to approximately 90 km upstream. Results were compared to those obtained from the same area in July 1998 using similar protocols. Depressed salinity, caused by extreme rainfall and associated high freshwater flow, persisted throughout much of the estuary, which had experienced periods of water-column stratification and hypoxia of underlying waters. Fifteen of the 20 sites, representing 299 km2 (76% of the survey area), also showed signs of benthic stress based on a multi-metric benthic index of biotic integrity (B-IBI). Benthic impacts included reductions in the abundance, diversity, and numbers of species and shifts in taxonomic composition, with a notable increase in dominance of the opportunistic polychaete Mediomastus ambiseta as other former dominant species declined. There was no significant increase in the extent of chemical contamination compared to pre-hurricane conditions. Storm-related reductions in dissolved oxygen and salinity were the more likely causes of the observed benthic impacts, though it was not possible, based on these results, to separate storm effects from seasonal changes in the benthos and annual episodes of summer anoxia and hypoxia.

  10. Thermal extremes mortality risk assessment in urban areas

    Directory of Open Access Journals (Sweden)

    Paulo Canário

    2010-06-01

    Full Text Available The impact of heat waves on mortality has been the subject of numerous studies and the focus of attention of various national and international governmental bodies. In the summer of 2003 alone, which was exceptionally hot, the number of deaths in 12 European countries increased by 70,000. The overall trend of warming will lead to an increase in frequency, duration and intensity of heat waves and to an increase in heat related mortality. The need to assess the risk of death due to extreme heat, at a detailed spatial scale, has determined the implementation of a research project based on a general model of risk for potentially destructive natural phenomena; the model uses the relationship between hazard and vulnerability and was designed primarily for urban areas. The major hazardous meteorological variables are those that determine the thermal complex (air temperature, radiative temperature, wind and humidity and the variables related to air quality (mainly ozone and Particulate matter. Vulnerability takes into account the population sensitivity (at various spatial scales and their exposure to thermal extremes.

  11. Understanding the complexity of the Lévy-walk nature of human mobility with a multi-scale cost∕benefit model.

    Science.gov (United States)

    Scafetta, Nicola

    2011-12-01

    human mobility, that the proposed model predicts the statistical properties of human mobility below 1 km ranges, where people just walk. In the latter case, the threshold between zone 1 and zone 2 may be around 100-200 m and, perhaps, may have been evolutionary determined by the natural human high resolution visual range, which characterizes an area of interest where the benefits are assumed to be randomly and uniformly distributed. This rich and suggestive interpretation of human mobility may characterize other complex random walk phenomena that may also be described by a N-piece fit Pareto distributions with increasing integer exponents. This study also suggests that distribution functions used to fit experimental probability distributions must be carefully chosen for not improperly obscuring the physics underlying a phenomenon.

  12. Understanding the complexity of the Lévy-walk nature of human mobility with a multi-scale cost/benefit model

    Science.gov (United States)

    Scafetta, Nicola

    2011-12-01

    mobility, that the proposed model predicts the statistical properties of human mobility below 1 km ranges, where people just walk. In the latter case, the threshold between zone 1 and zone 2 may be around 100-200 m and, perhaps, may have been evolutionary determined by the natural human high resolution visual range, which characterizes an area of interest where the benefits are assumed to be randomly and uniformly distributed. This rich and suggestive interpretation of human mobility may characterize other complex random walk phenomena that may also be described by a N-piece fit Pareto distributions with increasing integer exponents. This study also suggests that distribution functions used to fit experimental probability distributions must be carefully chosen for not improperly obscuring the physics underlying a phenomenon.

  13. Modeling, Forecasting and Mitigating Extreme Earthquakes

    Science.gov (United States)

    Ismail-Zadeh, A.; Le Mouel, J.; Soloviev, A.

    2012-12-01

    Recent earthquake disasters highlighted the importance of multi- and trans-disciplinary studies of earthquake risk. A major component of earthquake disaster risk analysis is hazards research, which should cover not only a traditional assessment of ground shaking, but also studies of geodetic, paleoseismic, geomagnetic, hydrological, deep drilling and other geophysical and geological observations together with comprehensive modeling of earthquakes and forecasting extreme events. Extreme earthquakes (large magnitude and rare events) are manifestations of complex behavior of the lithosphere structured as a hierarchical system of blocks of different sizes. Understanding of physics and dynamics of the extreme events comes from observations, measurements and modeling. A quantitative approach to simulate earthquakes in models of fault dynamics will be presented. The models reproduce basic features of the observed seismicity (e.g., the frequency-magnitude relationship, clustering of earthquakes, occurrence of extreme seismic events). They provide a link between geodynamic processes and seismicity, allow studying extreme events, influence of fault network properties on seismic patterns and seismic cycles, and assist, in a broader sense, in earthquake forecast modeling. Some aspects of predictability of large earthquakes (how well can large earthquakes be predicted today?) will be also discussed along with possibilities in mitigation of earthquake disasters (e.g., on 'inverse' forensic investigations of earthquake disasters).

  14. Extreme Programming Pocket Guide

    CERN Document Server

    Chromatic

    2003-01-01

    Extreme Programming (XP) is a radical new approach to software development that has been accepted quickly because its core practices--the need for constant testing, programming in pairs, inviting customer input, and the communal ownership of code--resonate with developers everywhere. Although many developers feel that XP is rooted in commonsense, its vastly different approach can bring challenges, frustrations, and constant demands on your patience. Unless you've got unlimited time (and who does these days?), you can't always stop to thumb through hundreds of pages to find the piece of info

  15. Upper extremity golf injuries.

    Science.gov (United States)

    Cohn, Michael A; Lee, Steven K; Strauss, Eric J

    2013-01-01

    Golf is a global sport enjoyed by an estimated 60 million people around the world. Despite the common misconception that the risk of injury during the play of golf is minimal, golfers are subject to a myriad of potential pathologies. While the majority of injuries in golf are attributable to overuse, acute traumatic injuries can also occur. As the body's direct link to the golf club, the upper extremities are especially prone to injury. A thorough appreciation of the risk factors and patterns of injury will afford accurate diagnosis, treatment, and prevention of further injury.

  16. Community responses to extreme climatic conditions

    Directory of Open Access Journals (Sweden)

    Frédéric JIGUET, Lluis BROTONS, Vincent DEVICTOR

    2011-06-01

    Full Text Available Species assemblages and natural communities are increasingly impacted by changes in the frequency and severity of extreme climatic events. Here we propose a brief overview of expected and demonstrated direct and indirect impacts of extreme events on animal communities. We show that differential impacts on basic biological parameters of individual species can lead to strong changes in community composition and structure with the potential to considerably modify the functional traits of the community. Sudden disequilibria have even been shown to induce irreversible shifts in marine ecosystems, while cascade effects on various taxonomic groups have been highlighted in Mediterranean forests. Indirect effects of extreme climatic events are expected when event-induced habitat changes (e.g. soil stability, vegetation composition, water flows altered by droughts, floods or hurricanes have differential consequences on species assembled within the communities. Moreover, in increasing the amplitude of trophic mismatches, extreme events are likely to turn many systems into ecological traps under climate change. Finally, we propose a focus on the potential impacts of an extreme heat wave on local assemblages as an empirical case study, analysing monitoring data on breeding birds collected in France. In this example, we show that despite specific populations were differently affected by local temperature anomalies, communities seem to be unaffected by a sudden heat wave. These results suggest that communities are tracking climate change at the highest possible rate [Current Zoology 57 (3: 406–413, 2011].

  17. Extreme-scale Algorithms and Solver Resilience

    Energy Technology Data Exchange (ETDEWEB)

    Dongarra, Jack [Univ. of Tennessee, Knoxville, TN (United States)

    2016-12-10

    A widening gap exists between the peak performance of high-performance computers and the performance achieved by complex applications running on these platforms. Over the next decade, extreme-scale systems will present major new challenges to algorithm development that could amplify this mismatch in such a way that it prevents the productive use of future DOE Leadership computers due to the following; Extreme levels of parallelism due to multicore processors; An increase in system fault rates requiring algorithms to be resilient beyond just checkpoint/restart; Complex memory hierarchies and costly data movement in both energy and performance; Heterogeneous system architectures (mixing CPUs, GPUs, etc.); and Conflicting goals of performance, resilience, and power requirements.

  18. Learning disabilities among extremely preterm children without neurosensory impairment: Comorbidity, neuropsychological profiles and scholastic outcomes.

    Science.gov (United States)

    Johnson, Samantha; Strauss, Victoria; Gilmore, Camilla; Jaekel, Julia; Marlow, Neil; Wolke, Dieter

    2016-12-01

    Children born extremely preterm are at high risk for intellectual disability, learning disabilities, executive dysfunction and special educational needs, but little is understood about the comorbidity of intellectual and learning disabilities in this population. This study explored comorbidity in intellectual disability (ID) and learning disabilities (LD) in children born extremely preterm (EP; disabilities. LD were associated with a 3 times increased risk for SEN. However, EP children with ID alone had poorer neuropsychological abilities and curriculum-based attainment than children with no disabilities, yet there was no increase in SEN provision among this group. EP children are at high risk for comorbid intellectual and learning disabilities. Education professionals should be aware of the complex nature of EP children's difficulties and the need for multi-domain assessments to guide intervention. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. Global Warming Denial: The Human Brain on Extremes

    Science.gov (United States)

    Marrouch, N.; Johnson, B. T.; Slawinska, J. M.

    2016-12-01

    Future assessments of climate change rely on multi-model intercomparisons, and projections of the extreme events frequency are of particular interest as associated with significant economic costs and social threats. Notably, systematically simulated increases in the number of extreme weather events agree well with observational data over the last decade. At the same time, as the climate grows more volatile, widespread denial of climate change and its anthropocentric causes continues to proliferate (based on nationally representative U.S. polls). Simultaneous increases in both high-impact exposure and its denial is in stark contrast with our knowledge of socio-natural dynamics and its models. Disentangling this paradox requires an understanding of the origins of global warming denial at an individual level, and how subsequently it propagates across social networks of many scales, shaping global policies. However, as the real world and its dynamical models are complex (high-dimensional and coupled), separating the particular feedback of interest remains a challenge. Here, we demonstrate this feedback in a controlled experiment, where increasing unpredictability using helplessness-training paradigms induces changes in global warming denial, and the endorsement of conservative ideology. We explain these results in the context of evolutionary theory framing self-deception and denial as remnants of evolutionary processes that shaped and facilitated the survival of the human species. Further we link these findings to changes in neural and higher-level cognitive processes in response to unpredictable stimuli. We argue that climate change denial is an example of an extreme belief system that carries the potential to threaten the wellbeing of both humans and other species alike. It is therefore crucial to better quantify climate denial using social informatics tools that provide the means to improve its representations in coupled socio-geophysical models to mitigate its

  20. Two-Dimensional Extreme Learning Machine

    Directory of Open Access Journals (Sweden)

    Bo Jia

    2015-01-01

    (BP networks. However, like many other methods, ELM is originally proposed to handle vector pattern while nonvector patterns in real applications need to be explored, such as image data. We propose the two-dimensional extreme learning machine (2DELM based on the very natural idea to deal with matrix data directly. Unlike original ELM which handles vectors, 2DELM take the matrices as input features without vectorization. Empirical studies on several real image datasets show the efficiency and effectiveness of the algorithm.

  1. Insertion sequences enrichment in extreme Red sea brine pool vent

    KAUST Repository

    Elbehery, Ali H. A.

    2016-12-03

    Mobile genetic elements are major agents of genome diversification and evolution. Limited studies addressed their characteristics, including abundance, and role in extreme habitats. One of the rare natural habitats exposed to multiple-extreme conditions, including high temperature, salinity and concentration of heavy metals, are the Red Sea brine pools. We assessed the abundance and distribution of different mobile genetic elements in four Red Sea brine pools including the world’s largest known multiple-extreme deep-sea environment, the Red Sea Atlantis II Deep. We report a gradient in the abundance of mobile genetic elements, dramatically increasing in the harshest environment of the pool. Additionally, we identified a strong association between the abundance of insertion sequences and extreme conditions, being highest in the harshest and deepest layer of the Red Sea Atlantis II Deep. Our comparative analyses of mobile genetic elements in secluded, extreme and relatively non-extreme environments, suggest that insertion sequences predominantly contribute to polyextremophiles genome plasticity.

  2. Coordination Nature of 4-Mercaptoaniline to Sn(II Ion: Formation of a One Dimensional Coordination Polymer and Its Decomposition to a Mono Nuclear Sn(IV Complex

    Directory of Open Access Journals (Sweden)

    Eon S. Burkett

    2014-12-01

    Full Text Available The coordination of the bifunctional ligand 4-mercaptoaniline with aqueo us tin(II metal ion was studied. A coordination polymer was synthesized when an aqueous solution of SnCl2 was treated with 4-MA. The crystalline material is stable under atmospheric conditions retaining its oxidation state. However, when submerged in a solution saturated with oxygen, the compound oxidizes to a mononuclear tin(IV complex. Both the compounds were characterized by single crystal X-ray diffraction studies. Although the structure of the tin(IV complex was previously reported, crystal structure of this compound was redetermined.

  3. Complex genetics controls natural variation among seed quality phenotypes in a recombinant inbred population of an interspecific cross between Solanum lycopersicum × Solanum pimpinellifolium

    NARCIS (Netherlands)

    Kazmi, R.H.; Khan, N.; Willems, L.A.J.; Heusden, van A.W.; Ligterink, J.W.; Hilhorst, H.W.M.

    2012-01-01

    Seed quality in tomato is associated with many complex physiological and genetic traits. While plant processes are frequently controlled by the action of small- to large-effect genes that follow classic Mendelian inheritance, our study suggests that seed quality is primarily quantitative and

  4. Underestimation of phosphorus fraction change in the supernatant after phosphorus adsorption onto iron oxides and iron oxide-natural organic matter complexes.

    Science.gov (United States)

    Yan, Jinlong; Jiang, Tao; Yao, Ying; Wang, Jun; Cai, Yuanli; Green, Nelson W; Wei, Shiqiang

    2017-05-01

    The phosphorus (P) fraction distribution and formation mechanism in the supernatant after P adsorption onto iron oxides and iron oxide-humic acid (HA) complexes were analyzed using the ultrafiltration method in this study. With an initial P concentration of 20mg/L (I=0.01mol/L and pH=7), it was shown that the colloid (1kDa-0.45μm) component of P accounted for 10.6%, 11.6%, 6.5%, and 4.0% of remaining total P concentration in the supernatant after P adsorption onto ferrihydrite (FH), goethite (GE), ferrihydrite-humic acid complex (FH-HA), goethite-humic acid complex (GE-HA), respectively. The oxide aggregates was the main mechanism for the formation of the colloid P in the supernatant. And colloidal adsorbent particles co-existing in the supernatant were another important reason for it. Additionally, dissolve organic matter dissolved from iron oxide-HA complexes could occupy large adsorption sites of colloidal iron causing less colloid P in the supernatant. Ultimately, we believe that the findings can provide a new way to deeply interpret the geochemical cycling of P, even when considering other contaminants such as organic pollutants, heavy metal ions, and arsenate at the sediment/soil-water interface in the real environment. Copyright © 2016. Published by Elsevier B.V.

  5. The Influence of Semantic and Morphological Complexity of Verbs on Sentence Recall: Implications for the Nature of Conceptual Representation and Category-Specific Deficits

    Science.gov (United States)

    Mobayyen, F.; de Almeida, R.G.

    2005-01-01

    One hundred and forty normal undergraduate students participated in a Proactive Interference (PI) experiment with sentences containing verbs from four different semantic and morphological classes (lexical causatives, morphological causatives, and morphologically complex and simplex perception verbs). Past research has shown significant PI build-up…

  6. Multidecadal oscillations in rainfall and hydrological extremes

    Science.gov (United States)

    Willems, Patrick

    2013-04-01

    Many studies have anticipated a worldwide increase in the frequency and intensity of precipitation extremes and floods since the last decade(s). Natural variability by climate oscillations partly determines the observed evolution of precipitation extremes. Based on a technique for the identification and analysis of changes in extreme quantiles, it is shown that hydrological extremes have oscillatory behaviour at multidecadal time scales. Results are based on nearly independent extremes extracted from long-term historical time series of precipitation intensities and river flows. Study regions include Belgium - The Netherlands (Meuse basin), Ethiopia (Blue Nile basin) and Ecuador (Paute basin). For Belgium - The Netherlands, the past 100 years showed larger and more hydrological extremes around the 1910s, 1950-1960s, and more recently during the 1990-2000s. Interestingly, the oscillations for southwestern Europe are anti-correlated with these of northwestern Europe, thus with oscillation highs in the 1930-1940s and 1970s. The precipitation oscillation peaks are explained by persistence in atmospheric circulation patterns over the North Atlantic during periods of 10 to 15 years. References: Ntegeka V., Willems P. (2008), 'Trends and multidecadal oscillations in rainfall extremes, based on a more than 100 years time series of 10 minutes rainfall intensities at Uccle, Belgium', Water Resources Research, 44, W07402, doi:10.1029/2007WR006471 Mora, D., Willems, P. (2012), 'Decadal oscillations in rainfall and air temperature in the Paute River Basin - Southern Andes of Ecuador', Theoretical and Applied Climatology, 108(1), 267-282, doi:0.1007/s00704-011-0527-4 Taye, M.T., Willems, P. (2011). 'Influence of climate variability on representative QDF predictions of the upper Blue Nile Basin', Journal of Hydrology, 411, 355-365, doi:10.1016/j.jhydrol.2011.10.019 Taye, M.T., Willems, P. (2012). 'Temporal variability of hydro-climatic extremes in the Blue Nile basin', Water

  7. Nature and timing of the final collision of Central Asian Orogenic Belt: insights from basic intrusion in the Xilin Gol Complex, Inner Mongolia, China

    NARCIS (Netherlands)

    Li, Y.; Zhou, H.; Brouwer, F.M.; Xiao, W.; Wijbrans, J.R.; Zhao, J.; Zhong, Z.; Liu, H.

    2014-01-01

    The Solonker suture zone of the Central Asian Orogenic Belt (CAOB) records the final closure of the Paleo-Asian Ocean. The nature and timing of final collision along the Solonker suture has long been controversial, partly because of an incomplete record of isotopic ages and differing interpretations

  8. Hydrodynamic modelling of extreme flood events in the Kashmir valley in India

    Science.gov (United States)

    Jain, Manoj; Parvaze, Sabah

    2017-04-01

    Floods are one of the most predominant, costly and deadly hazards of all natural vulnerabilities. Every year, floods exert a heavy toll on human life and property in many parts of the world. The prediction of river stages and discharge during flood extremes plays a vital role in planning structural and non-structural measures of flood management. The predictions are also valuable to prepare the flood inundation maps and river floodplain zoning. In the Kashmir Valley, floods occur mainly and very often in the Jhelum Basin mostly due to extreme precipitation events and rugged mountainous topography of the basin. These floods cause extreme damage to life and property in the valley from time to time. Excessive rainfall, particularly in higher sub-catchments causes the snow to melt resulting in excessive runoff downhill to the streams causing floods in the Kashmir Valley where Srinagar city is located. However, very few hydrological studies have been undertaken for the Jhelum Basin mainly due to non-availability of hydrological data due to very complex mountainous terrain. Therefore, the present study has been conducted to model the extreme flood events in the Jhelum Basin in Kashmir Valley. An integrated NAM and MIKE 11 HD model has been setup for Jhelum basin up to Ram Munshi Bagh gauging site and then four most extreme historical flood events in the time series has been analyzed separately including the most recent and most extreme flood event of 2014. In September 2014, the Kashmir Valley witnessed the most severe flood in the past 60 years due to catastrophic rainfall from 1st to 6th September wherein the valley received unprecedented rainfall of more than 650 mm in just 3 days breaking record of many decades. The MIKE 11 HD and NAM model has been calibrated using 21 years (1985-2005) data and validated using 9 years (2006-2014) data. The efficiency indices of the model for calibration and validation period is 0.749 and 0.792 respectively. The model simulated

  9. Synthetic Biomaterials to Rival Nature's Complexity-a Path Forward with Combinatorics, High-Throughput Discovery, and High-Content Analysis.

    Science.gov (United States)

    Zhang, Douglas; Lee, Junmin; Kilian, Kristopher A

    2017-10-01

    Cells in tissue receive a host of soluble and insoluble signals in a context-dependent fashion, where integration of these cues through a complex network of signal transduction cascades will define a particular outcome. Biomaterials scientists and engineers are tasked with designing materials that can at least partially recreate this complex signaling milieu towards new materials for biomedical applications. In this progress report, recent advances in high throughput techniques and high content imaging approaches that are facilitating the discovery of efficacious biomaterials are described. From microarrays of synthetic polymers, peptides and full-length proteins, to designer cell culture systems that present multiple biophysical and biochemical cues in tandem, it is discussed how the integration of combinatorics with high content imaging and analysis is essential to extracting biologically meaningful information from large scale cellular screens to inform the design of next generation biomaterials. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. CARS spectroscopy of the NaH2 collision complex: The nature of the Na(3 2P)H2 exciplex - ab initio calculations and experimental results

    International Nuclear Information System (INIS)

    Vivie-Riedle, R. de; Hering, P.; Kompa, K.L.

    1990-01-01

    CARS has been used to analyze the rovibronic state distribution of H 2 after collision with Na(3 2 P). New lines, which do not correspond to H 2 lines are observed in the CARS spectrum. The experiments point to the formation of a complex of Na(3 2 P)H 2 in A 2 B 2 symmetry. Ab initio calculations of the A 2 B 2 potential were performed. On this surface the vibrational spectra of the exciplex is evaluated. The observed lines can be attributed to vibrational transitions in the complex, in which combinational modes are involved. The connection of experimental and theoretical results indicates that a collisionally stabilized exciplex molecule is formed during the quenching process. (orig.)

  11. Is southwestern China experiencing more frequent precipitation extremes?

    International Nuclear Information System (INIS)

    Liu, Meixian; Xu, Xianli; Wang, Kelin; Sun, Alexander Y; Liu, Wen; Zhang, Xiaoyan

    2014-01-01

    Climate extremes have and will continue to cause severe damages to buildings and natural environments around the world. A full knowledge of the probability of the climate extremes is important for the management and mitigation of natural hazards. Based on Mann–Kendall trend test and copulas, this study investigated the characteristics of precipitation extremes as well as their implications in southwestern China (Yunnan, Guangxi and Guizhou Province), through analyzing the changing trends and probabilistic characteristics of six indices, including the consecutive dry days, consecutive wet days, annual total wet day precipitation, heavy precipitation days (R25), max 5 day precipitation amount (Rx5) and the rainy days (RDs). Results showed that the study area had generally become drier (regional mean annual precipitation decreased by 11.4 mm per decade) and experienced enhanced precipitation extremes in the past 60 years. Relatively higher risk of drought in Yuanan and flood in Guangxi was observed, respectively. However, the changing trends of the precipitation extremes were not spatially uniform: increasing risk of extreme wet events for Guangxi and Guizhou, and increasing probability of concurrent extreme wet and dry events for Yunnan. Meanwhile, trend analyses of the 10 year return levels of the selected indices implied that the severity of droughts decreased in Yunnan but increased significantly in Guangxi and Guizhou, and the severity of floods increased in Yunnan and Guangxi in the past decades. Hence, the policy-makers need to be aware of the different characterizations and the spatial heterogeneity of the precipitation extremes. (letters)

  12. Dissociation kinetics of Fe(III)- and Al(III)-natural organic matter complexes at pH 6.0 and 8.0 and 25 °C

    Science.gov (United States)

    Jones, Adele M.; Pham, A. Ninh; Collins, Richard N.; Waite, T. David

    2009-05-01

    The rate at which iron- and aluminium-natural organic matter (NOM) complexes dissociate plays a critical role in the transport of these elements given the readiness with which they hydrolyse and precipitate. Despite this, there have only been a few reliable studies on the dissociation kinetics of these complexes suggesting half-times of some hours for the dissociation of Fe(III) and Al(III) from a strongly binding component of NOM. First-order dissociation rate constants are re-evaluated here at pH 6.0 and 8.0 and 25 °C using both cation exchange resin and competing ligand methods for Fe(III) and a cation exchange resin method only for Al(III) complexes. Both methods provide similar results at a particular pH with a two-ligand model accounting satisfactorily for the dissociation kinetics results obtained. For Fe(III), half-times on the order of 6-7 h were obtained for dissociation of the strong component and 4-5 min for dissociation of the weak component. For aluminium, the half-times were on the order of 1.5 h and 1-2 min for the strong and weak components, respectively. Overall, Fe(III) complexes with NOM are more stable than analogous complexes with Al(III), implying Fe(III) may be transported further from its source upon dilution and dispersion.

  13. Structural basis for the inhibition of M1 family aminopeptidases by the natural product actinonin: Crystal structure in complex with E. coli aminopeptidase N.

    Science.gov (United States)

    Ganji, Roopa Jones; Reddi, Ravikumar; Gumpena, Rajesh; Marapaka, Anil Kumar; Arya, Tarun; Sankoju, Priyanka; Bhukya, Supriya; Addlagatta, Anthony

    2015-05-01

    Actinonin is a pseudotripeptide that displays a high affinity towards metalloproteases including peptide deformylases (PDFs) and M1 family aminopeptidases. PDF and M1 family aminopeptidases belong to thermolysin-metzincin superfamily. One of the major differences in terms of substrate binding pockets between these families is presence (in M1 aminopeptidases) or absence (in PDFs) of an S1 substrate pocket. The binding mode of actinonin to PDFs has been established previously; however, it is not clear how the actinonin, without a P1 residue, would bind to the M1 aminopeptidases. Here we describe the crystal structure of Escherichia coli aminopeptidase N (ePepN), a model protein of the M1 family aminopeptidases in complex with actinonin. For comparison we have also determined the structure of ePepN in complex with a well-known tetrapeptide inhibitor, amastatin. From the comparison of the actinonin and amastatin ePepN complexes, it is clear that the P1 residue is not critical as long as strong metal chelating head groups, like hydroxamic acid or α-hydroxy ketone, are present. Results from this study will be useful for the design of selective and efficient hydroxamate inhibitors against M1 family aminopeptidases. © 2015 The Protein Society.

  14. Daily extreme temperature multifractals in Catalonia (NE Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Burgueño, A. [Departament d' Astronomia i Meteorologia, Universitat de Barcelona, Barcelona (Spain); Lana, X., E-mail: francisco.javier.lana@upc.edu [Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Barcelona (Spain); Serra, C. [Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Barcelona (Spain); Martínez, M.D. [Departament de Física Aplicada, Universitat Politècnica de Catalunya, Barcelona (Spain)

    2014-02-01

    The multifractal character of the daily extreme temperatures in Catalonia (NE Spain) is analyzed by means of the multifractal detrended fluctuation analysis (MF-DFA) applied to 65 thermometric records covering years 1950–2004. Although no clear spatial patterns of the multifractal spectrum parameters appear, factor scores deduced from Principal Component analysis indicate some signs of spatial gradients. Additionally, the daily extreme temperature series are classified depending on their complex time behavior, through four multifractal parameters (Hurst exponent, Hölder exponent with maximum spectrum, spectrum asymmetry and spectrum width). As a synthesis of the three last parameters, a basic measure of complexity is proposed through a normalized Complexity Index. Its regional behavior is found to be free of geographical dependences. This index represents a new step towards the description of the daily extreme temperatures complexity.

  15. Daily extreme temperature multifractals in Catalonia (NE Spain)

    International Nuclear Information System (INIS)

    Burgueño, A.; Lana, X.; Serra, C.; Martínez, M.D.

    2014-01-01

    The multifractal character of the daily extreme temperatures in Catalonia (NE Spain) is analyzed by means of the multifractal detrended fluctuation analysis (MF-DFA) applied to 65 thermometric records covering years 1950–2004. Although no clear spatial patterns of the multifractal spectrum parameters appear, factor scores deduced from Principal Component analysis indicate some signs of spatial gradients. Additionally, the daily extreme temperature series are classified depending on their complex time behavior, through four multifractal parameters (Hurst exponent, Hölder exponent with maximum spectrum, spectrum asymmetry and spectrum width). As a synthesis of the three last parameters, a basic measure of complexity is proposed through a normalized Complexity Index. Its regional behavior is found to be free of geographical dependences. This index represents a new step towards the description of the daily extreme temperatures complexity.

  16. Early neurodevelopmental outcomes of extremely preterm infants.

    Science.gov (United States)

    Rogers, Elizabeth E; Hintz, Susan R

    2016-12-01

    Infants born at extreme preterm gestation are at risk for both death and disability. Although rates of survival have improved for this population, and some evidence suggests a trend toward decreased neuromotor impairment over the past decades, a significant improvement in overall early neurodevelopmental outcome has not yet been realized. This review will examine the rates and types of neurodevelopmental impairment seen after extremely preterm birth, including neurosensory, motor, cognitive, and behavioral outcomes. We focus on early outcomes in the first 18-36 months of life, as the majority of large neonatal studies examining neurodevelopmental outcomes stop at this age. However, this early age is clearly just a first glimpse into lifetime outcomes; the neurodevelopmental effects of extreme prematurity may last through school age, adolescence, and beyond. Importantly, prematurity appears to be an independent risk factor for adverse development, but this population demonstrates considerable variability in the types and severity of impairments. Understanding both the nature and prevalence of neurodevelopmental impairment among extremely preterm infants is important because it can lead to targeted interventions that in turn may lead to improved outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Overview of the biology of extreme events

    Science.gov (United States)

    Gutschick, V. P.; Bassirirad, H.

    2008-12-01

    Extreme events have, variously, meteorological origins as in heat waves or precipitation extremes, or biological origins as in pest and disease eruptions (or tectonic, earth-orbital, or impact-body origins). Despite growing recognition that these events are changing in frequency and intensity, a universal model of ecological responses to these events is slow to emerge. Extreme events, negative and positive, contrast with normal events in terms of their effects on the physiology, ecology, and evolution of organisms, hence also on water, carbon, and nutrient cycles. They structure biogeographic ranges and biomes, almost surely more than mean values often used to define biogeography. They are challenging to study for obvious reasons of field-readiness but also because they are defined by sequences of driving variables such as temperature, not point events. As sequences, their statistics (return times, for example) are challenging to develop, as also from the involvement of multiple environmental variables. These statistics are not captured well by climate models. They are expected to change with climate and land-use change but our predictive capacity is currently limited. A number of tools for description and analysis of extreme events are available, if not widely applied to date. Extremes for organisms are defined by their fitness effects on those organisms, and are specific to genotypes, making them major agents of natural selection. There is evidence that effects of extreme events may be concentrated in an extended recovery phase. We review selected events covering ranges of time and magnitude, from Snowball Earth to leaf functional loss in weather events. A number of events, such as the 2003 European heat wave, evidence effects on water and carbon cycles over large regions. Rising CO2 is the recent extreme of note, for its climatic effects and consequences for growing seasons, transpiration, etc., but also directly in its action as a substrate of photosynthesis

  18. Complex Nonlinearity Chaos, Phase Transitions, Topology Change and Path Integrals

    CERN Document Server

    Ivancevic, Vladimir G

    2008-01-01

    Complex Nonlinearity: Chaos, Phase Transitions, Topology Change and Path Integrals is a book about prediction & control of general nonlinear and chaotic dynamics of high-dimensional complex systems of various physical and non-physical nature and their underpinning geometro-topological change. The book starts with a textbook-like expose on nonlinear dynamics, attractors and chaos, both temporal and spatio-temporal, including modern techniques of chaos–control. Chapter 2 turns to the edge of chaos, in the form of phase transitions (equilibrium and non-equilibrium, oscillatory, fractal and noise-induced), as well as the related field of synergetics. While the natural stage for linear dynamics comprises of flat, Euclidean geometry (with the corresponding calculation tools from linear algebra and analysis), the natural stage for nonlinear dynamics is curved, Riemannian geometry (with the corresponding tools from nonlinear, tensor algebra and analysis). The extreme nonlinearity – chaos – corresponds to th...

  19. A note on extreme sets

    Directory of Open Access Journals (Sweden)

    Radosław Cymer

    2017-10-01

    Full Text Available In decomposition theory, extreme sets have been studied extensively due to its connection to perfect matchings in a graph. In this paper, we first define extreme sets with respect to degree-matchings and next investigate some of their properties. In particular, we prove the generalized Decomposition Theorem and give a characterization for the set of all extreme vertices in a graph.

  20. Sensitivity of Rainfall Extremes Under Warming Climate in Urban India

    Science.gov (United States)

    Ali, H.; Mishra, V.

    2017-12-01

    Extreme rainfall events in urban India halted transportation, damaged infrastructure, and affected human lives. Rainfall extremes are projected to increase under the future climate. We evaluated the relationship (scaling) between rainfall extremes at different temporal resolutions (daily, 3-hourly, and 30 minutes), daily dewpoint temperature (DPT) and daily air temperature at 850 hPa (T850) for 23 urban areas in India. Daily rainfall extremes obtained from Global Surface Summary of Day Data (GSOD) showed positive regression slopes for most of the cities with median of 14%/K for the period of 1979-2013 for DPT and T850, which is higher than Clausius-Clapeyron (C-C) rate ( 7%). Moreover, sub-daily rainfall extremes are more sensitive to both DPT and T850. For instance, 3-hourly rainfall extremes obtained from Tropical Rainfall Measurement Mission (TRMM 3B42 V7) showed regression slopes more than 16%/K aginst DPT and T850 for the period of 1998-2015. Half-hourly rainfall extremes from the Integrated Multi-satellitE Retrievals (IMERGE) of Global precipitation mission (GPM) also showed higher sensitivity against changes in DPT and T850. The super scaling of rainfall extremes against changes in DPT and T850 can be attributed to convective nature of precipitation in India. Our results show that urban India may witness non-stationary rainfall extremes, which, in turn will affect stromwater designs and frequency and magniture of urban flooding.

  1. Likelihood estimators for multivariate extremes

    KAUST Repository

    Huser, Raphaë l; Davison, Anthony C.; Genton, Marc G.

    2015-01-01

    The main approach to inference for multivariate extremes consists in approximating the joint upper tail of the observations by a parametric family arising in the limit for extreme events. The latter may be expressed in terms of componentwise maxima, high threshold exceedances or point processes, yielding different but related asymptotic characterizations and estimators. The present paper clarifies the connections between the main likelihood estimators, and assesses their practical performance. We investigate their ability to estimate the extremal dependence structure and to predict future extremes, using exact calculations and simulation, in the case of the logistic model.

  2. Likelihood estimators for multivariate extremes

    KAUST Repository

    Huser, Raphaël

    2015-11-17

    The main approach to inference for multivariate extremes consists in approximating the joint upper tail of the observations by a parametric family arising in the limit for extreme events. The latter may be expressed in terms of componentwise maxima, high threshold exceedances or point processes, yielding different but related asymptotic characterizations and estimators. The present paper clarifies the connections between the main likelihood estimators, and assesses their practical performance. We investigate their ability to estimate the extremal dependence structure and to predict future extremes, using exact calculations and simulation, in the case of the logistic model.

  3. Further outlooks: extremely uncomfortable; Die weiteren Aussichten: extrem ungemuetlich

    Energy Technology Data Exchange (ETDEWEB)

    Resenhoeft, T.

    2006-07-01

    Climate is changing extremely in the last decades. Scientists dealing with extreme weather, should not only stare at computer simulations. They have also to turn towards psyche, seriously personal experiences, knowing statistics, relativise supposed sensational reports and last not least collecting more data. (GL)

  4. Experimental studies on the nature of bonding of DNA/bipyridyl-(ethylenediamine)platinum(II) and DNA/netropsin complexes in solution and oriented wet-spun films

    Science.gov (United States)

    Marlowe, R. L.; Szabo, A.; Lee, S. A.; Rupprecht, A.

    2002-03-01

    The stability of complexes of NaDNA with bipyridyl-(ethylenediamine)platinum(II) (abbreviated [(bipy)Pt(en)]) and with netropsin has been studied using two techniques: (i) ultraviolet melting experiments were done on NaDNA/[(bipy)Pt(en)], showing that the [(bipy)Pt(en)] ligand stabilizes the DNA double helix structure; and (ii) swelling measurements (via optical microscopy) as a function of relative humidity were done on wet-spun oriented films of NaDNA/[(bipy)Pt(en)] and of NaDNA/netropsin. The swelling data shows that an irreversible transition of the films occurs at high relative humidity, first for the NaDNA/netropsin, then for pure NaDNA, and lastly for the NaDNA/[(bipy)Pt(en)]. These results are indicative that the [(bipy)Pt(en)] complex stabilizes the intermolecular bonds which mediate the film swelling characteristics. A model is suggested for the binding of [(bipy)Pt(en)] to DNA to explain why the swelling experiments show this ligand as increasing the intermolecular bond strength between the DNA double helices, while netropsin decreases this degree of stabilization.

  5. Synthetic murataite-3C, a complex form for long-term immobilization of nuclear waste. Crystal structure and its comparison with natural analogues

    Energy Technology Data Exchange (ETDEWEB)

    Pakhomova, Anna S.; Krivovichev, Sergey V. [St. Petersburg State Univ. (Russian Federation). Dept. of Crystallography; Yudintsev, Sergey V. [Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry, St. Petersburg (Russian Federation); Stefanovsky, Sergey V. [MosNPO Radon, Moscow (Russian Federation)

    2013-03-01

    The structure of synthetic murataite-3C intended for long-term immobilization of high-level radioactive waste has been solved using crystals prepared by melting in an electric furnace at 1500 C. The material is cubic, F- anti 43m, a = 14.676(15) A, V = 3161.31(57) A{sup 3}. The structure is based upon a three-dimensional framework consisting of {alpha}-Keggin [Al{sup [4]}Ti{sub 12}{sup [6]}O{sub 40}] clusters linked by sharing the O5 atoms. The Keggin-cluster-framework interpenetrates with the metal-oxide substructure that can be considered as a derivative of the fluorite structure. The crystal chemical formula of synthetic murataite-3C derived from the obtained structure model can be written as {sup [8]}Ca{sub 6}{sup [8]}Ca{sub 4}{sup [6]}Ti{sub 12}{sup [5]}Ti{sub 4}{sup [4]}AlO{sub 42}. Its comparison with the natural murataite shows that the synthetic material has a noticeably less number of vacancies in the cation substructure and contains five instead of four symmetrically independent cation positions. The presence of the additional site essentially increases the capacity of synthetic murataite with respect to large heavy cations such as actinides, rare earth and alkaline earth metals in comparison with the material of natural origin. (orig.)

  6. Assessing Climate Variability using Extreme Rainfall and ...

    African Journals Online (AJOL)

    user1

    extreme frequency); the average intensity of rainfall from extreme events ... frequency and extreme intensity indices, suggesting that extreme events are more frequent and intense during years with high rainfall. The proportion of total rainfall from ...

  7. Extreme heat and runoff extremes in the Swiss Alps

    Directory of Open Access Journals (Sweden)

    M. Zappa

    2007-06-01

    Full Text Available The hydrological response of Swiss river basins to the 2003 European summer heatwave was evaluated by a combined analysis of historical discharge records and specific applications of distributed hydrological modeling. In the summer of 2003, the discharge from headwater streams of the Swiss Central Plateau was only 40%–60% of the long-term average. For alpine basins runoff was about 60%–80% of the average. Glacierized basins showed the opposite behavior. According to the degree of glacierization, the average summer runoff was close or even above average. The hydrological model PREVAH was applied for the period 1982–2005. Even if the model was not calibrated for such extreme meteorological conditions, it was well able to simulate the hydrological responses of three basins. The aridity index φ describes feedbacks between hydrological and meteorological anomalies, and was adopted as an indicator of hydrological drought. The anomalies of φ and temperature in the summer of 2003 exceeded the 1982–2005 mean by more than 2 standard deviations. Catchments without glaciers showed negative correlations between φ and discharge R. In basins with about 15% glacierization, φ and R were not correlated. River basins with higher glacier percentages showed a positive correlation between φ and R. Icemelt was positively correlated with φ and reduced the variability of discharge with larger amounts of meltwater. Runoff generation from the non-glaciated sub-areas was limited by high evapotranspiration and reduced precipitation. The 2003 summer heatwave could be a precursor to similar events in the near future. Hydrological models and further data analysis will allow the identification of the most sensitive regions where heatwaves may become a recurrent natural hazard with large environmental, social and economical impacts.

  8. Ca2+-induced PRE-NMR changes in the troponin complex reveal the possessive nature of the cardiac isoform for its regulatory switch.

    Directory of Open Access Journals (Sweden)

    Nicole M Cordina

    Full Text Available The interaction between myosin and actin in cardiac muscle, modulated by the calcium (Ca2+ sensor Troponin complex (Tn, is a complex process which is yet to be fully resolved at the molecular level. Our understanding of how the binding of Ca2+ triggers conformational changes within Tn that are subsequently propagated through the contractile apparatus to initiate muscle activation is hampered by a lack of an atomic structure for the Ca2+-free state of the cardiac isoform. We have used paramagnetic relaxation enhancement (PRE-NMR to obtain a description of the Ca2+-free state of cardiac Tn by describing the movement of key regions of the troponin I (cTnI subunit upon the release of Ca2+ from Troponin C (cTnC. Site-directed spin-labeling was used to position paramagnetic spin labels in cTnI and the changes in the interaction between cTnI and cTnC subunits were then mapped by PRE-NMR. The functionally important regions of cTnI targeted in this study included the cTnC-binding N-region (cTnI57, the inhibitory region (cTnI143, and two sites on the regulatory switch region (cTnI151 and cTnI159. Comparison of 1H-15N-TROSY spectra of Ca2+-bound and free states for the spin labeled cTnC-cTnI binary constructs demonstrated the release and modest movement of the cTnI switch region (∼10 Å away from the hydrophobic N-lobe of troponin C (cTnC upon the removal of Ca2+. Our data supports a model where the non-bound regulatory switch region of cTnI is highly flexible in the absence of Ca2+ but remains in close vicinity to cTnC. We speculate that the close proximity of TnI to TnC in the cardiac complex is favourable for increasing the frequency of collisions between the N-lobe of cTnC and the regulatory switch region, counterbalancing the reduction in collision probability that results from the incomplete opening of the N-lobe of TnC that is unique to the cardiac isoform.

  9. COMPLEX GEOLOGICAL–GEOPHYSICAL 3D MODEL OF THE CRUST IN THE SOUTHEASTERN FENNOSCANDIAN SHIELD: NATURE OF DENSITY LAYERING OF THE CRUST AND THE CRUST–MANTLE BOUNDARY

    Directory of Open Access Journals (Sweden)

    V. N. Glaznev

    2015-01-01

    Full Text Available The complex geophysical 3D model of the Earth's crust and the upper mantle is created for the Archaean Karelian Craton and the Late Palaeoproterozoic accretionary Svecofennian Orogen of the southeastern Fennoscandian Shield with the use of methods of complex inversion of geophysical data based on stochastic description of interrelations of physical properties of the medium (density, P-wave velocity, and heat generation. To develop the model, we use results of deep seismic studies, gravity and surficial heat flow data on the studied region. Numerical solutions of 3D problems are obtained in the spherical setting with an allowance for the Earth's surface topography. The geophysical model is correlated with the regional geological data on the surface and results of seismic CMP studies along 4B, FIRE-1 and FIRE-3-3A profiles. Based on results of complex geophysical simulation and geological interpretation of the 3D model, the following conclusions are drawn. (1 The nearly horizontal density layering of the continental crust is superimposed on the previously formed geological structure; rock differentiation by density is decreasing with depth; the density layering is controlled by the recent and near-recent state of the crust, but can be disturbed by the latest deformations. (2 Temperature variations at the Moho are partially determined by local variations of heat generation in the mantle, which, in turn, are related to local features of its origin and transformation. (3 The concept of the lower continental crust being a reflectivity zone and the concept of the lower continental crust being a layer of high density and velocity are not equivalent: the lower crust is the deepest, high-density element of near-horizontal layering, whereas the seismic image of the reflectivity zone is primarily related to transformation of the crust as a result of magmatic under- and intraplating under conditions of extension and mantle-plume activity. (4 At certain

  10. Understanding the Reach of Agricultural Impacts from Climate Extremes in the Agricultural Model Intercomparison and Improvement Project (AgMIP)

    Science.gov (United States)

    Ruane, A. C.

    2016-12-01

    The Agricultural Model Intercomparison and Improvement Project (AgMIP) has been working since 2010 to build a modeling framework capable of representing the complexities of agriculture, its dependence on climate, and the many elements of society that depend on food systems. AgMIP's 30+ activities explore the interconnected nature of climate, crop, livestock, economics, food security, and nutrition, using common protocols to systematically evaluate the components of agricultural assessment and allow multi-model, multi-scale, and multi-method analysis of intertwining changes in socioeconomic development, environmental change, and technological adaptation. AgMIP is now launching Coordinated Global and Regional Assessments (CGRA) with a particular focus on unforeseen consequences of development strategies, interactions between global and local systems, and the resilience of agricultural systems to extreme climate events. Climate extremes shock the agricultural system through local, direct impacts (e.g., droughts, heat waves, floods, severe storms) and also through teleconnections propagated through international trade. As the climate changes, the nature of climate extremes affecting agriculture is also likely to change, leading to shifting intensity, duration, frequency, and geographic extents of extremes. AgMIP researchers are developing new scenario methodologies to represent near-term extreme droughts in a probabilistic manner, field experiments that impose heat wave conditions on crops, increased resolution to differentiate sub-national drought impacts, new behavioral functions that mimic the response of market actors faced with production shortfalls, analysis of impacts from simultaneous failures of multiple breadbasket regions, and more detailed mapping of food and socioeconomic indicators into food security and nutrition metrics that describe the human impact in diverse populations. Agricultural models illustrate the challenges facing agriculture, allowing

  11. Solvent extraction of some fission products using tetracycline as a complexing agent : dependence on the ph of the aqueous phase and on the nature of some inorganic anions

    International Nuclear Information System (INIS)

    Cunha, I.I.L.; Nastasi, M.J.C.

    1982-10-01

    The behavior of tetracycline as a complexing agent in solvent extraction studies is presented. The extraction curves for the fission products 90 Sr, 140 Ba, 99 Mo, sup(99m)Tc, 95 Zr, 95 Nb, 103 Ru and also for U have been determined for the extraction system tetracycline-benzyl alcohol. The extraction dependence on the pH of the aqueous phase as well as on the kind of electrolyte present was examined. As a practical application, the possiblity of using the tetracycline-benzyl alcohol system for separation of the fission products present in a mixture of them, as well as for the separation of uranium from those elements, was tested. (Author) [pt

  12. Phosphorus-containing podands. 14. Effect of alkyl substituents at phosphorus atom on complexing ability of neutral monopodands. On the nature of abnormal alkyl effect

    International Nuclear Information System (INIS)

    Tsvetkov, E.N.; Evreinov, V.I.; Bondarenko, N.A.; Safronova, Z.V.

    1996-01-01

    The previously revealed unusual effect of alkyl substituents at phosphorus atom in phosphorus-containing monopodands of the general formula o-R 2 P(O)C 6 H 4 (OCH 2 CH 2 ) n OC 6 H 4 P(O)R 2 -o, n=1-5, R = Alk, Ph, OEt on their complexing ability towards alkali metals cations has been interpreted. Alkyl radicals create great spatial obstacles to rotation of R 2 P(O) fragments around the C-P bond as compared with other substituents, which gives rise to the appearance of anomalous alkyl effect. Solvation is an additional factor, which can bring about the anomalous effect appearance or a change in the degree of its pronouncement. 47 refs.; 3 figs.; 7 tabs

  13. Nature and regional significance of unconformities associated with the Middle Ordovician Hagan K-bentonite complex in the North American midcontinent

    Science.gov (United States)

    Kolata, Dennis R.; Huff, W.D.; Bergstrom, Stig M.

    1998-01-01

    Stratal patterns of the Middle Ordovician Hagan K-bentonite complex and associated rocks show that the Black River-Trenton unconformity in the North American midcontinent formed through the complex interplay of eustasy, sediment accumulation rates, siliciclastic influx, bathymetry, seawater chemistry, and perhaps local tectonic uplift. The unconformity is diachronous and is an amalgamated surface that resulted from local late Turinian lowstand exposure followed by regional early Chatfieldian transgressive drowning and sediment starvation. The duration of the unconformity is greatest in southern Wisconsin, northern Illinois, and northern Indiana, where the Deicke and Millbrig K-bentonite Beds converge at the unconformity. On the basis of published isotopic ages for the Deicke and Millbrig beds, it is possible that in these regions erosion and non-deposition spanned a period of as much as 3.2 m.y. Two broad coeval depositional settings are recognized within the North American midcontinent during early Chatfieldian time. 1) An inner shelf, subtidal facies of fossiliferous shale (Spechts Ferry Shale Member and Ion Shale Member of the Decorah Formation) and argillaceous lime mudstone and skeletal wackestone (Guttenberg and Kings Lake Limestone Members) extended from the Canadian shield and Transcontinental arch southeastward through Minnesota, Wisconsin, Iowa, and Missouri. 2) A seaward, relatively deep subtidal, sediment-starved, middle shelf extended eastward from the Mississippi Valley region to the Taconian foreland basins in the central and southern Appalachians and southward through the pericratonic Arkoma and Black Warrior basins. In the inner shelf region, the Black River-Trenton unconformity is a composite of at least two prominent hardground omission surfaces, one at the top of the Castlewood and Carimona Limestone Members and the other at the top of the Guttenberg and Kings Lake Limestone Members, both merging to a single surface in the middle shelf region

  14. Natural bond orbital analysis of molecular interactions: Theoretical study of W(CO)5 complexes with E(PH3)2 and NHEMe ligands (E=C, Si, Ge, Sn, Pb)

    International Nuclear Information System (INIS)

    Nguyen Thi Ai Nhung; Huynh Thi Phuong Loan; Duong Tuan Quang; Pham Van Tat

    2014-01-01

    The complexes with ligands carbodiphosphorane-analogues (called tetrylones) [(CO) 5 W-{E(PH 3 ) 2 }] (W5-EP 2 ) and N-heterocyclic carbene-analogues (called tetrylenes) [(CO) 5 W-{NHE Me }] (W5-NHE Me ) when E=C-Pb have been studied using natural bond orbital (NBO) method. The NBO analysis provides a consistent picture of the chemical bonding is two entire families of transition metal complexes of tetrylone and tetrylene ligands in term of donor-acceptor interactions, showing the correlation of these interactions with Wiberg bond indies (WBI), natural partial charges, and the energetically highest lying occupied molecular orbitals for σ and π orbitals of free ligands E(PH 3 ) 2 and NHE Me . Analysis of the bonding situation reveals that in E(PH 3 ) 2 and NHE Me ligands, the energy level of the π orbital rises, whereas that of the σ orbital decreases as atom E becomes heavier. The complexes with head-on-bonded ligands have (CO) 5 W←E donation which comes from the σ-lone-pair orbital of E(PH 3 ) 2 and NHE Me where E=C for tetrylones and E=C, Si, Ge for tetrylenes, whereas the (CO) 5 W←E donation in the side-on bonded complexes when E becomes heavier arises from the π-lone-pair orbital of E(PH 3 ) 2 and NHE Me ligands which is the HOMO of the free ligands. This makes the heavier adducts of tetrylones and tetrylenes become stronger donors than the lighter systems. The NBO analysis suggests that the E(PH 3 ) 2 ligands are strong σ-donors and strong π-acceptors while the NHE Me ligands are strong σ-donors and weak π-acceptors. This is possible for tetrylones that have two lone-pair orbitals available for donation, whereas the tetrylenes have only one lone-pair orbital available for donation. (author)

  15. Extreme Facial Expressions Classification Based on Reality Parameters

    Science.gov (United States)

    Rahim, Mohd Shafry Mohd; Rad, Abdolvahab Ehsani; Rehman, Amjad; Altameem, Ayman

    2014-09-01

    Extreme expressions are really type of emotional expressions that are basically stimulated through the strong emotion. An example of those extreme expression is satisfied through tears. So to be able to provide these types of features; additional elements like fluid mechanism (particle system) plus some of physics techniques like (SPH) are introduced. The fusion of facile animation with SPH exhibits promising results. Accordingly, proposed fluid technique using facial animation is the real tenor for this research to get the complex expression, like laugh, smile, cry (tears emergence) or the sadness until cry strongly, as an extreme expression classification that's happens on the human face in some cases.

  16. A dependence modelling study of extreme rainfall in Madeira Island

    Science.gov (United States)

    Gouveia-Reis, Délia; Guerreiro Lopes, Luiz; Mendonça, Sandra

    2016-08-01

    The dependence between variables plays a central role in multivariate extremes. In this paper, spatial dependence of Madeira Island's rainfall data is addressed within an extreme value copula approach through an analysis of maximum annual data. The impact of altitude, slope orientation, distance between rain gauge stations and distance from the stations to the sea are investigated for two different periods of time. The results obtained highlight the influence of the island's complex topography on the spatial distribution of extreme rainfall in Madeira Island.

  17. Management of the mangled extremity

    NARCIS (Netherlands)

    Prasarn, Mark L.; Helfet, David L.; Kloen, Peter

    2012-01-01

    The management of a mangled extremity continues to be a matter of debate. With modern advances in trauma resuscitation, microvascular tissue transfer, and fracture fixation, severe traumatic extremity injuries that would historically have been amputated are often salvaged. Even if preserving a

  18. A decade of weather extremes

    NARCIS (Netherlands)

    Coumou, Dim; Rahmstorf, Stefan

    The ostensibly large number of recent extreme weather events has triggered intensive discussions, both in- and outside the scientific community, on whether they are related to global warming. Here, we review the evidence and argue that for some types of extreme - notably heatwaves, but also

  19. Attitude extremity, consensus and diagnosticity

    NARCIS (Netherlands)

    van der Pligt, J.; Ester, P.; van der Linden, J.

    1983-01-01

    Studied the effects of attitude extremity on perceived consensus and willingness to ascribe trait terms to others with either pro- or antinuclear attitudes. 611 Ss rated their attitudes toward nuclear energy on a 5-point scale. Results show that attitude extremity affected consensus estimates. Trait

  20. Technical Seismicity as Natural Extreme in Karviná Region

    Czech Academy of Sciences Publication Activity Database

    Kaláb, Zdeněk; Kořínek, R.; Hrubešová, E.

    2009-01-01

    Roč. 4, 2a (2009), s. 87-94 ISSN 1896-3145. [Ochrona środowiska w górnictwie podziemnym, odkrywkowym i otworowym. Bochnia, 20.05.2009-22.05.2009] Grant - others:GA ČR(CZ) GA103/09/2007 Institutional research plan: CEZ:AV0Z30860518 Keywords : mining induced seismicity * seismic loading Subject RIV: DC - Siesmology, Volcanology, Earth Structure

  1. Tambora and the mackerel year: phenology and fisheries during an extreme climate event

    Science.gov (United States)

    Alexander, Karen E.; Leavenworth, William B.; Hall, Carolyn; Mattocks, Steven; Bittner, Steven M.; Klein, Emily; Staudinger, Michelle D.; Bryan, Alexander; Rosset, Julianne; Willis, Theodore V.; Carr, Benjamin H.; Jordaan, Adrian

    2017-01-01

    Global warming has increased the frequency of extreme climate events, yet responses of biological and human communities are poorly understood, particularly for aquatic ecosystems and fisheries. Retrospective analysis of known outcomes may provide insights into the nature of adaptations and trajectory of subsequent conditions. We consider the 1815 eruption of the Indonesian volcano Tambora and its impact on Gulf of Maine (GoM) coastal and riparian fisheries in 1816. Applying complex adaptive systems theory with historical methods, we analyzed fish export data and contemporary climate records to disclose human and piscine responses to Tambora’s extreme weather at different spatial and temporal scales while also considering sociopolitical influences. Results identified a tipping point in GoM fisheries induced by concatenating social and biological responses to extreme weather. Abnormal daily temperatures selectively affected targeted fish species—alewives, shad, herring, and mackerel—according to their migration and spawning phenologies and temperature tolerances. First to arrive, alewives suffered the worst. Crop failure and incipient famine intensified fishing pressure, especially in heavily settled regions where dams already compromised watersheds. Insufficient alewife runs led fishers to target mackerel, the next species appearing in abundance along the coast; thus, 1816 became the “mackerel year.” Critically, the shift from riparian to marine fisheries persisted and expanded after temperatures moderated and alewives recovered. We conclude that contingent human adaptations to extraordinary weather permanently altered this complex system. Understanding how adaptive responses to extreme events can trigger unintended consequences may advance long-term planning for resilience in an uncertain future.

  2. Changes in the probability of co-occurring extreme climate events

    Science.gov (United States)

    Diffenbaugh, N. S.

    2017-12-01

    Extreme climate events such as floods, droughts, heatwaves, and severe storms exert acute stresses on natural and human systems. When multiple extreme events co-occur, either in space or time, the impacts can be substantially compounded. A diverse set of human interests - including supply chains, agricultural commodities markets, reinsurance, and deployment of humanitarian aid - have historically relied on the rarity of extreme events to provide a geographic hedge against the compounded impacts of co-occuring extremes. However, changes in the frequency of extreme events in recent decades imply that the probability of co-occuring extremes is also changing, and is likely to continue to change in the future in response to additional global warming. This presentation will review the evidence for historical changes in extreme climate events and the response of extreme events to continued global warming, and will provide some perspective on methods for quantifying changes in the probability of co-occurring extremes in the past and future.

  3. Extremely high major histocompatibility complex class IIb gene ...

    Indian Academy of Sciences (India)

    tial for the genetic management of the captive alligator; thus much research on this ..... protected; at the same time, we must strengthen the education about alligator ... Province, Zoology Practical Skills Training Center in Fuyang. Teachers ...

  4. I parchi eolici: la complessa interazione tra natura, uomo e tecnologia - The wind farms: the complex interaction among nature, man and technology

    Directory of Open Access Journals (Sweden)

    Massimiliano Masullo

    2015-10-01

    Full Text Available Sin dai tempi antichi l’uomo ha costruito macchine che, sfruttando l’energia del vento, lo hanno aiutato a nutrire se stesso, la terra e a svolgere lavorazioni complesse. Con la scoperta dell’elettricità la funzione di queste macchine è cambiata radicalmente. Negli ultimi venti anni, politiche d'incentivazione hanno portato allo sviluppo di impianti eolici ed alla loro diffusione sul territorio, determinando una interazione sempre più intensa fra turbine eoliche, ambiente circostante ed uomo. Questo articolo presentata una rassegna dei principali fattori che determinano o modificano la percezione dell’impatto che queste macchine hanno sull’uomo e sull’ambiente circostante. ------ Since ancient times the man has built machines which exploiting the energy of the wind have helped to feed himself, the land and carry out complex operations. With the discovery of electricity the function of these machines is changed radically. In the last twenty years, incentive policies have led to the development of wind farms and their diffusion over the territory, resulting in a more intense interaction between wind turbines, environment and man. This article presents a review of the main factors that determine or affect the perception of the impact that these machines have on humans and the surrounding environment.

  5. Dinitrosyl iron complexes with natural thiol-containing ligands in aqueous solutions: Synthesis and some physico-chemical characteristics (A methodological review).

    Science.gov (United States)

    Vanin, Anatoly F; Borodulin, Rostislav R; Mikoyan, Vasak D

    2017-06-01

    Two approaches to the synthesis of dinitrosyl iron complexes (DNIC) with glutathione and l-cysteine in aqueous solutions based on the use of gaseous NO and appropriate S-nitrosothiols, viz., S-nitrosoglutathione (GS-NO) or S-nitrosocysteine (Cys-NO), respectively, are considered. A schematic representation of a vacuum unit for generation and accumulation of gaseous NO purified from the NO 2 admixture and its application for obtaining aqueous solutions of DNIC in a Thunberg apparatus is given. To achieve this, a solution of bivalent iron in distilled water is loaded into the upper chamber of the Thunberg apparatus, while the thiol solution in an appropriate buffer (рН 7.4) is loaded into its lower chamber. Further steps, which include degassing, addition of gaseous NO, shaking of both solutions and formation of the Fe 2+ -thiol mixture, culminate in the synthesis of DNIC. The second approach consists in a stepwise addition of Fe 2+ salts and nitrite to aqueous solutions of glutathione or cysteine. In the presence of Fe 2+ and after the increase in рН to the physiological level, GS-NO or Cys-NO generated at acid media (pH nitrosonium ions (NO + ) and the peculiar characteristics of the EPR signal of their mononuclear form (M-DNIC). Copyright © 2017. Published by Elsevier Inc.

  6. Quantitative analysis of higher hydrocarbons in natural gas using coupled solid-phase extraction / supercritiacal fluid extraction with on-line GC analysis

    NARCIS (Netherlands)

    Janssen, J.G.M.; Cramers, C.A.M.G.; Meulen-Kuijk, van der L.; Smit, A.L.C.; Sandra, P.; Devos, G.

    1993-01-01

    Characterisation of natural gas with respect to the hydrocarbon content is a challenging analytical problem due to the extremely low concentrations and the complexity of the matrix. In this publication a method is described for fully on-line preconcentration and analysis of n-nonane and higher

  7. The political economy of corporate social responsibility and community development: a case study of Norway's Snoehvit natural gas complex

    Energy Technology Data Exchange (ETDEWEB)

    Klick, Matthew T.

    2009-07-01

    This project uses stakeholder evidence from semi-structured interviews to analyze the relative effectiveness of an oil company's stated 'corporate social responsibility' (CSR) initiatives in a new, Arctic host community. Specifically, this project analyzes the outcomes of StatoilHydro initiatives to date in Hammerfest, Norway, where the Snoehvit (Snow White) natural gas project began production in 2007. It gauges the ability of 'socially responsible' approaches to development to internalize negative externalisation and promote positive 'spin-offs'. Arctic countries are increasingly prioritizing petroleum development. The convergence of dramatic climate change, increasing energy demands, and high energy prices has made the Arctic an alluring frontier for the oil industry and Arctic governments. Small Arctic communities are increasingly playing host to large energy projects with the potential for dramatic cultural, social, environmental, and economic upheaval, but also economic growth and increased human capital. In this case study, CSR initiatives resulted in a broader accounting of social costs and benefits, an outcome that better internalized externalities, and pareto-improving trades between stakeholders and industry. (Author). 87 refs., 5 figs., 5 tabs

  8. Time series analysis of diverse extreme phenomena: universal features

    Science.gov (United States)

    Eftaxias, K.; Balasis, G.

    2012-04-01

    The field of study of complex systems holds that the dynamics of complex systems are founded on universal principles that may used to describe a great variety of scientific and technological approaches of different types of natural, artificial, and social systems. We suggest that earthquake, epileptic seizures, solar flares, and magnetic storms dynamics can be analyzed within similar mathematical frameworks. A central property of aforementioned extreme events generation is the occurrence of coherent large-scale collective behavior with very rich structure, resulting from repeated nonlinear interactions among the corresponding constituents. Consequently, we apply the Tsallis nonextensive statistical mechanics as it proves an appropriate framework in order to investigate universal principles of their generation. First, we examine the data in terms of Tsallis entropy aiming to discover common "pathological" symptoms of transition to a significant shock. By monitoring the temporal evolution of the degree of organization in time series we observe similar distinctive features revealing significant reduction of complexity during their emergence. Second, a model for earthquake dynamics coming from a nonextensive Tsallis formalism, starting from first principles, has been recently introduced. This approach leads to an energy distribution function (Gutenberg-Richter type law) for the magnitude distribution of earthquakes, providing an excellent fit to seismicities generated in various large geographic areas usually identified as seismic regions. We show that this function is able to describe the energy distribution (with similar non-extensive q-parameter) of solar flares, magnetic storms, epileptic and earthquake shocks. The above mentioned evidence of a universal statistical behavior suggests the possibility of a common approach for studying space weather, earthquakes and epileptic seizures.

  9. Behavior under Extreme Conditions: The Titanic Disaster

    OpenAIRE

    Bruno S. Frey; David A. Savage; Benno Torgler

    2011-01-01

    During the night of April 14, 1912, the RMS Titanic collided with an iceberg on her maiden voyage. Two hours and 40 minutes later she sank, resulting in the loss of 1,501 lives—more than two-thirds of her 2,207 passengers and crew. This remains one of the deadliest peacetime maritime disasters in history and by far the most famous. For social scientists, evidence about how people behaved as the Titanic sunk offers a quasi-natural field experiment to explore behavior under extreme conditions o...

  10. Physics of condensed matter at extreme conditions

    International Nuclear Information System (INIS)

    Ross, M.

    1988-01-01

    The study of matter under extreme conditions is a highly interdisciplinary subject with broad applications to materials science, geophysics and astrophysics. High-pressure properties are studied in the laboratory using static and dynamic techniques. The two differ drastically in the methods of generating and measuring pressure and in the fundamentally different nature of the final compressed state. This article covers a very broad range of conditions, intended to present an overview of important recent developments and to emphasize the behavior of materials and the kinds of properties now being studied

  11. Spatial dependence of extreme rainfall

    Science.gov (United States)

    Radi, Noor Fadhilah Ahmad; Zakaria, Roslinazairimah; Satari, Siti Zanariah; Azman, Muhammad Az-zuhri

    2017-05-01

    This study aims to model the spatial extreme daily rainfall process using the max-stable model. The max-stable model is used to capture the dependence structure of spatial properties of extreme rainfall. Three models from max-stable are considered namely Smith, Schlather and Brown-Resnick models. The methods are applied on 12 selected rainfall stations in Kelantan, Malaysia. Most of the extreme rainfall data occur during wet season from October to December of 1971 to 2012. This period is chosen to assure the available data is enough to satisfy the assumption of stationarity. The dependence parameters including the range and smoothness, are estimated using composite likelihood approach. Then, the bootstrap approach is applied to generate synthetic extreme rainfall data for all models using the estimated dependence parameters. The goodness of fit between the observed extreme rainfall and the synthetic data is assessed using the composite likelihood information criterion (CLIC). Results show that Schlather model is the best followed by Brown-Resnick and Smith models based on the smallest CLIC's value. Thus, the max-stable model is suitable to be used to model extreme rainfall in Kelantan. The study on spatial dependence in extreme rainfall modelling is important to reduce the uncertainties of the point estimates for the tail index. If the spatial dependency is estimated individually, the uncertainties will be large. Furthermore, in the case of joint return level is of interest, taking into accounts the spatial dependence properties will improve the estimation process.

  12. Evolution caused by extreme events.

    Science.gov (United States)

    Grant, Peter R; Grant, B Rosemary; Huey, Raymond B; Johnson, Marc T J; Knoll, Andrew H; Schmitt, Johanna

    2017-06-19

    Extreme events can be a major driver of evolutionary change over geological and contemporary timescales. Outstanding examples are evolutionary diversification following mass extinctions caused by extreme volcanism or asteroid impact. The evolution of organisms in contemporary time is typically viewed as a gradual and incremental process that results from genetic change, environmental perturbation or both. However, contemporary environments occasionally experience strong perturbations such as heat waves, floods, hurricanes, droughts and pest outbreaks. These extreme events set up strong selection pressures on organisms, and are small-scale analogues of the dramatic changes documented in the fossil record. Because extreme events are rare, almost by definition, they are difficult to study. So far most attention has been given to their ecological rather than to their evolutionary consequences. We review several case studies of contemporary evolution in response to two types of extreme environmental perturbations, episodic (pulse) or prolonged (press). Evolution is most likely to occur when extreme events alter community composition. We encourage investigators to be prepared for evolutionary change in response to rare events during long-term field studies.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'. © 2017 The Author(s).

  13. Dual-tree complex wavelet transform and SVD based acoustic noise reduction and its application in leak detection for natural gas pipeline

    Science.gov (United States)

    Yu, Xuchao; Liang, Wei; Zhang, Laibin; Jin, Hao; Qiu, Jingwei

    2016-05-01

    During the last decades, leak detection for natural gas pipeline has become one of the paramount concerns of pipeline operators and researchers across the globe. However, acoustic wave method has been proved to be an effective way to identify and localize leakage for gas pipeline. Considering the fact that noises inevitably exist in the acoustic signals collected, noise reduction should be enforced on the signals for subsequent data mining and analysis. Thus, an integrated acoustic noise reduction method based on DTCWT and SVD is proposed in this study. The method is put forward based on the idea that noise reduction strategy should match the characteristics of the noisy signal. According to previous studies, it is known that the energy of acoustic signals collected under leaking condition is mainly concentrated in low-frequency portion (0-100 Hz). And ultralow-frequency component (0-5 Hz), which is taken as the characteristic frequency band in this study, can propagate a relatively longer distance and be captured by sensors. Therefore, in order to filter the noises and to reserve the characteristic frequency band, DTCWT is taken as the core to conduct multilevel decomposition and refining for acoustic signals and SVD is employed to eliminate noises in non-characteristic bands. Both simulation and field experiments show that DTCWT-SVD is an excellent method for acoustic noise reduction. At the end of this study, application in leakage localization shows that it becomes much easier and a little more accurate to estimate the location of leak hole after noise reduction by DTCWT-SVD.

  14. Extreme Energy in China

    Energy Technology Data Exchange (ETDEWEB)

    Khanna, Nina [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fridley, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cai, Lixue [China Petrochemical Corporations (China)

    2013-06-01

    Over the last decade, China has focused its policies simultaneously on moderating the rapid energy demand growth that has been driven by three decades of rapid economic growth and industrialization and on increasing its energy supply. In spite of these concerted efforts, however, China continues to face growing energy supply challenges, particularly with accelerating demand for oil and natural gas, both of which are now heavily dependent on imports. On the supply side, the recent 11th and 12th Five-Year Plans have emphasized accelerating conventional and nonconventional oil and gas exploration and development through pricing reforms, pipeline infrastructure expansions and 2015 production targets for shale gas and coal seam methane. This study will analyze China’s new and nonconventional oil and gas resources base, possible development paths and outlook, and the potential role for these nonconventional resources in meeting oil and gas demand. The nonconventional resources currently being considered by China and included in this study include: shale gas, coal seam methane (coal mine methane and coal bed methane), tight gas, in-situ coal gasification, tight oil and oil shale, and gas hydrates.

  15. Computational discovery of extremal microstructure families

    Science.gov (United States)

    Chen, Desai; Skouras, Mélina; Zhu, Bo; Matusik, Wojciech

    2018-01-01

    Modern fabrication techniques, such as additive manufacturing, can be used to create materials with complex custom internal structures. These engineered materials exhibit a much broader range of bulk properties than their base materials and are typically referred to as metamaterials or microstructures. Although metamaterials with extraordinary properties have many applications, designing them is very difficult and is generally done by hand. We propose a computational approach to discover families of microstructures with extremal macroscale properties automatically. Using efficient simulation and sampling techniques, we compute the space of mechanical properties covered by physically realizable microstructures. Our system then clusters microstructures with common topologies into families. Parameterized templates are eventually extracted from families to generate new microstructure designs. We demonstrate these capabilities on the computational design of mechanical metamaterials and present five auxetic microstructure families with extremal elastic material properties. Our study opens the way for the completely automated discovery of extremal microstructures across multiple domains of physics, including applications reliant on thermal, electrical, and magnetic properties. PMID:29376124

  16. Nature of unresolved complex mixture in size-distributed emissions from residential wood combustion as measured by thermal desorption-gas chromatography-mass spectrometry

    Science.gov (United States)

    Hays, Michael D.; Smith, N. Dean; Dong, Yuanji

    2004-08-01

    Unresolved complex mixture (UCM) is an analytical artifact of gas chromatographs of combustion source-related fine aerosol extracts. In this study the UCM is examined in size-resolved fine aerosol emissions from residential wood combustion. The aerosols are sorted by size in an electrical low-pressure impactor (ELPI) and subsequently analyzed by thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS). A semiquantitative system for predicting the branched alkane, cycloalkane, alkylbenzene, C3-, C4-, C5-alkylbenzene, methylnaphthalene, C3-, C4-, C5-alkylnaphthalene, methylphenanthrene C2-, C3-alkylphenanthrene, and dibenzothiophene concentrations in the UCM is introduced. Analysis by TD/GS/MS detects UCM on each ELPI stage for all six combustion tests. The UCM baseline among the different fuel types is variable. In particular, the UCM of Pseudotsuga sp. is enriched in later-eluting compounds of lower volatility. A high level of reproducibility is achieved in determining UCM areas. UCM fractions (UCM ion area/total extracted ion chromatograph area) by individual ELPI stage return a mean relative standard deviation of 19.1% over the entire combustion test set, indicating a highly consistent UCM fraction across the ELPI size boundaries. Among the molecular ions investigated, branched alkane (m/z 57) and dibenzothiophene (m/z 212 and 226) constituents are most abundant in UCM emissions from RWC, collectively accounting for 64-95% of the targeted chemical species. The total UCM emissions span 446-756 mg/kg of dry biomass burned and correspond to an upper limit of 7.1% of the PM2.5 mass. The UCM emissions are primarily accumulation mode (0.1 μm ≤ aerodynamic diameter (da) ≤ 1 μm), with a geometric mean diameter (dg) range of 120.3-518.4 nm. UCM in PM2.5 is chemically asymmetric (shifted to finer da), typically clustering at da ≤ 1 μm. Measurable shifts in dg and changes in distribution widths (σg) on an intratest basis suggest that the particle density

  17. Meteorological Drivers of Extreme Air Pollution Events

    Science.gov (United States)

    Horton, D. E.; Schnell, J.; Callahan, C. W.; Suo, Y.

    2017-12-01

    The accumulation of pollutants in the near-surface atmosphere has been shown to have deleterious consequences for public health, agricultural productivity, and economic vitality. Natural and anthropogenic emissions of ozone and particulate matter can accumulate to hazardous concentrations when atmospheric conditions are favorable, and can reach extreme levels when such conditions persist. Favorable atmospheric conditions for pollutant accumulation include optimal temperatures for photochemical reaction rates, circulation patterns conducive to pollutant advection, and a lack of ventilation, dispersion, and scavenging in the local environment. Given our changing climate system and the dual ingredients of poor air quality - pollutants and the atmospheric conditions favorable to their accumulation - it is important to characterize recent changes in favorable meteorological conditions, and quantify their potential contribution to recent extreme air pollution events. To facilitate our characterization, this study employs the recently updated Schnell et al (2015) 1°×1° gridded observed surface ozone and particulate matter datasets for the period of 1998 to 2015, in conjunction with reanalysis and climate model simulation data. We identify extreme air pollution episodes in the observational record and assess the meteorological factors of primary support at local and synoptic scales. We then assess (i) the contribution of observed meteorological trends (if extant) to the magnitude of the event, (ii) the return interval of the meteorological event in the observational record, simulated historical climate, and simulated pre-industrial climate, as well as (iii) the probability of the observed meteorological trend in historical and pre-industrial climates.

  18. Estimation of frequency of occurrence of extreme natural external events of very high intensity on the base of (non)available data - Estimation of frequency of rare natural external events of very high intensity on the base of (non)available data

    International Nuclear Information System (INIS)

    Holy, J.; Kolar, L.; Jaros, M.; Hladky, M.; Mlady, O.

    2014-01-01

    The relatively frequent natural external events are usually of minor safety importance, because the NPPs are, with a significant safety margin, constructed and operated to withstand the effects of them. Thus, risk analysis is typically devoted to the natural events of exceptional intensity, which mostly have not occurred up to now, but which still could happen with some low probability, but critical consequences. Since 'direct' plant specific data providing evidence about such events to occur is not at disposal, special data treatment and extrapolation methods have to be employed for frequency estimation. The paper summarizes possible approach to estimation of rate event frequency by means of extrapolation from available data and points out the potential problems and challenges encountered during the analysis. The general framework is commented in the presentation, regarding the effects of choice of probabilistic distribution (Gumbel distribution versus the others), methods of work with data records (To take out some observations and why?) and analysis of quality of input data sets (To mix the data sets from different sources or not? To use 'old' observations?) In the first part of the paper, the approach to creation of NPP Dukovany deterministic design basis regarding natural external events, which was used in past, is summarized. The second, major part of the paper, is devoted to involvement of the ideas of probabilistic safety assessment into safety assessment of external hazards, including such specific topics as addressing the quality of available data records, discussion on possible violation of common assumptions expected to be valid by the rules of statistical data analysis and the ways how to fix it, the choice of probabilistic distribution modeling data variability etc. The examples of results achieved for NPP Dukovany site in Czech republic are given in the final section. This paper represents a coordinated effort with participation of experts and staff

  19. Dismounted Complex Blast Injury.

    Science.gov (United States)

    Andersen, Romney C; Fleming, Mark; Forsberg, Jonathan A; Gordon, Wade T; Nanos, George P; Charlton, Michael T; Ficke, James R

    2012-01-01

    The severe Dismounted Complex Blast Injury (DCBI) is characterized by high-energy injuries to the bilateral lower extremities (usually proximal transfemoral amputations) and/or upper extremity (usually involving the non-dominant side), in addition to open pelvic injuries, genitourinary, and abdominal trauma. Initial resuscitation and multidisciplinary surgical management appear to be the keys to survival. Definitive treatment follows general principals of open wound management and includes decontamination through aggressive and frequent debridement, hemorrhage control, viable tissue preservation, and appropriate timing of wound closure. These devastating injuries are associated with paradoxically favorable survival rates, but associated injuries and higher amputation levels lead to more difficult reconstructive challenges.

  20. The biomechanics of upper extremity kinematic and kinetic modeling: applications to rehabilitation engineering.

    Science.gov (United States)

    Slavens, Brooke A; Harris, Gerald F

    2008-01-01

    Human motion analysis has evolved from the lower extremity to the upper extremity. Rehabilitation engineering is reliant upon three-dimensional biome-chanical models for a thorough understanding of upper body motions and forces in order to improve treatment methods, rehabilitation strategies and to prevent injury. Due to the complex nature of upper body movements, a standard biomechanical model does not exist. This paper reviews several kinematic and kinetic rehabilitation engineering models from the literature. These models may capture a single joint; multijoints such as the shoulder, elbow and wrist; or a combination of joints and an ambulatory aid, which serves as the extension of the upper arm. With advances in software and hardware, new models continuously arise due to the clinical questions at hand. When designing a biomechanical upper extremity model, several key components must be determined. These include deciding on the anatomic segments of the model, the number of markers and placement on bony landmarks, the definition of joint coordinate systems, and the description of the joint motions. It is critical to apply the proper model to further our understanding of pathologic populations.

  1. Book of extremes why the 21st century isn’t like the 20th century

    CERN Document Server

    Lewis, Ted G

    2014-01-01

    What makes the 21st century different from the 20th century? This century is the century of extremes -- political, economic, social, and global black-swan events happening with increasing frequency and severity. Book of Extremes is a tour of the current reality as seen through the lens of complexity theory – the only theory capable of explaining why the Arab Spring happened and why it will happen again; why social networks in the virtual world behave like flashmobs in the physical world; why financial bubbles blow up in our faces and will grow and burst again; why the rich get richer and will continue to get richer regardless of governmental policies; why the future of economic wealth and national power lies in comparative advantage and global trade; why natural disasters will continue to get bigger and happen more frequently; and why the Internet – invented by the US -- is headed for a global monopoly controlled by a non-US corporation. It is also about the extreme innovations and heroic innovators yet t...

  2. Statistical Model of Extreme Shear

    DEFF Research Database (Denmark)

    Larsen, Gunner Chr.; Hansen, Kurt Schaldemose

    2004-01-01

    In order to continue cost-optimisation of modern large wind turbines, it is important to continously increase the knowledge on wind field parameters relevant to design loads. This paper presents a general statistical model that offers site-specific prediction of the probability density function...... by a model that, on a statistically consistent basis, describe the most likely spatial shape of an extreme wind shear event. Predictions from the model have been compared with results from an extreme value data analysis, based on a large number of high-sampled full-scale time series measurements...... are consistent, given the inevitabel uncertainties associated with model as well as with the extreme value data analysis. Keywords: Statistical model, extreme wind conditions, statistical analysis, turbulence, wind loading, statistical analysis, turbulence, wind loading, wind shear, wind turbines....

  3. Racial Extremism in the Army

    National Research Council Canada - National Science Library

    Hudson, Walter M

    1998-01-01

    ... modem phenomenon of "skinheads." I then discuss the history of white supremacist extremism in the Army, culminating in the December, 1995 murders of two black civilians by soldiers assigned to the 82d Airborne Division at Fort Bragg, North Carolina...

  4. Holographic complexity and spacetime singularities

    Energy Technology Data Exchange (ETDEWEB)

    Barbón, José L.F. [Instituto de Física Teórica IFT UAM/CSIC,C/ Nicolás Cabrera 13, Campus Universidad Autónoma de Madrid,Madrid 28049 (Spain); Rabinovici, Eliezer [Racah Institute of Physics, The Hebrew University,Jerusalem 91904 (Israel); Laboratoire de Physique Théorique et Hautes Energies, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05 (France)

    2016-01-15

    We study the evolution of holographic complexity in various AdS/CFT models containing cosmological crunch singularities. We find that a notion of complexity measured by extremal bulk volumes tends to decrease as the singularity is approached in CFT time, suggesting that the corresponding quantum states have simpler entanglement structure at the singularity.

  5. Holographic complexity and spacetime singularities

    International Nuclear Information System (INIS)

    Barbón, José L.F.; Rabinovici, Eliezer

    2016-01-01

    We study the evolution of holographic complexity in various AdS/CFT models containing cosmological crunch singularities. We find that a notion of complexity measured by extremal bulk volumes tends to decrease as the singularity is approached in CFT time, suggesting that the corresponding quantum states have simpler entanglement structure at the singularity.

  6. Cosmic Complexity

    Science.gov (United States)

    Mather, John C.

    2012-01-01

    What explains the extraordinary complexity of the observed universe, on all scales from quarks to the accelerating universe? My favorite explanation (which I certainty did not invent) ls that the fundamental laws of physics produce natural instability, energy flows, and chaos. Some call the result the Life Force, some note that the Earth is a living system itself (Gaia, a "tough bitch" according to Margulis), and some conclude that the observed complexity requires a supernatural explanation (of which we have many). But my dad was a statistician (of dairy cows) and he told me about cells and genes and evolution and chance when I was very small. So a scientist must look for me explanation of how nature's laws and statistics brought us into conscious existence. And how is that seemll"!gly Improbable events are actually happening a!1 the time? Well, the physicists have countless examples of natural instability, in which energy is released to power change from simplicity to complexity. One of the most common to see is that cooling water vapor below the freezing point produces snowflakes, no two alike, and all complex and beautiful. We see it often so we are not amazed. But physlc!sts have observed so many kinds of these changes from one structure to another (we call them phase transitions) that the Nobel Prize in 1992 could be awarded for understanding the mathematics of their common features. Now for a few examples of how the laws of nature produce the instabilities that lead to our own existence. First, the Big Bang (what an insufficient name!) apparently came from an instability, in which the "false vacuum" eventually decayed into the ordinary vacuum we have today, plus the most fundamental particles we know, the quarks and leptons. So the universe as a whole started with an instability. Then, a great expansion and cooling happened, and the loose quarks, finding themselves unstable too, bound themselves together into today's less elementary particles like protons and

  7. Legacies from extreme drought increase ecosystem sensitivity to future extremes

    Science.gov (United States)

    Smith, M. D.; Knapp, A.; Hoover, D. L.; Avolio, M. L.; Felton, A. J.; Wilcox, K. R.

    2016-12-01

    Climate extremes, such as drought, are increasing in frequency and intensity, and the ecological consequences of these extreme events can be substantial and widespread. Although there is still much to be learned about how ecosystems will respond to an intensification of drought, even less is known about the factors that determine post-drought recovery of ecosystem function. Such knowledge is particularly important because post-drought recovery periods can be protracted depending on the extent to which key plant populations, community structure and biogeochemical processes are affected. These drought legacies may alter ecosystem function for many years post-drought and may impact future sensitivity to climate extremes. We experimentally imposed two extreme growing season droughts in a central US grassland to assess the impacts of repeated droughts on ecosystem resistance (response) and resilience (recovery). We found that this grassland was not resistant to the first extreme drought due to reduced productivity and differential sensitivity of the co-dominant C4 grass (Andropogon gerardii) and C3 forb (Solidago canadensis) species. This differential sensitivity led to a reordering of species abundances within the plant community. Yet, despite this large shift in plant community composition, which persisted post-drought, the grassland was highly resilient post-drought, due to increased abundance of the dominant C4 grass. Because of this shift to increased C4 grass dominance, we expected that previously-droughted grassland would be more resistant to a second extreme drought. However, contrary to these expectations, previously droughted grassland was more sensitive to drought than grassland that had not experienced drought. Thus, our result suggest that legacies of drought (shift in community composition) may increase ecosystem sensitivity to future extreme events.

  8. Global predictability of temperature extremes

    Science.gov (United States)

    Coughlan de Perez, Erin; van Aalst, Maarten; Bischiniotis, Konstantinos; Mason, Simon; Nissan, Hannah; Pappenberger, Florian; Stephens, Elisabeth; Zsoter, Ervin; van den Hurk, Bart

    2018-05-01

    Extreme temperatures are one of the leading causes of death and disease in both developed and developing countries, and heat extremes are projected to rise in many regions. To reduce risk, heatwave plans and cold weather plans have been effectively implemented around the world. However, much of the world’s population is not yet protected by such systems, including many data-scarce but also highly vulnerable regions. In this study, we assess at a global level where such systems have the potential to be effective at reducing risk from temperature extremes, characterizing (1) long-term average occurrence of heatwaves and coldwaves, (2) seasonality of these extremes, and (3) short-term predictability of these extreme events three to ten days in advance. Using both the NOAA and ECMWF weather forecast models, we develop global maps indicating a first approximation of the locations that are likely to benefit from the development of seasonal preparedness plans and/or short-term early warning systems for extreme temperature. The extratropics generally show both short-term skill as well as strong seasonality; in the tropics, most locations do also demonstrate one or both. In fact, almost 5 billion people live in regions that have seasonality and predictability of heatwaves and/or coldwaves. Climate adaptation investments in these regions can take advantage of seasonality and predictability to reduce risks to vulnerable populations.

  9. Cellulolytic properties of an extremely thermophilic anaerobe

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, J A; Morgan, H W; Daniel, R M [Waikato Univ., Hamilton (New Zealand). Microbial Biochemistry and Biotechnology Unit

    1990-09-01

    An extremely thermophilic anaerobe was isolated from a New Zealand hot spring by incubating bacterial mat strands in a medium containing xylan. The Gramreaction-negative organism that was subsequently purified had a temperature optimum of 70deg C and a pH optimum of 7.0. The isolate, designated strain H173, grew on a restricted range of carbon sources. In batch culture H173 could degrade Avicel completely when supplied at 5 or 10 g l{sup -1}. There was an initial growth phase, during which a cellulase complex was produced and carbohydrates fermented to form acetic and lactic acids, followed by a phase where cells were not metabolising but the cellulase complex actively converted cellulose to glucose. When co-cultered with strain Rt8.B1, an ethanologenic extreme thermophile, glucose was fermented to ethanol and acetate, and no reducing sugars accumulated in the medium. In pH controlled batch culture H173 produced an increased amount of lactate and acetate but there was again a phase when reducing sugars accumulated in the medium, and these were converted to ethanol by co-culture with Rt8.B1. (orig.).

  10. Normalization Strategies for Enhancing Spatio-Temporal Analysis of Social Media Responses during Extreme Events: A Case Study based on Analysis of Four Extreme Events using Socio-Environmental Data Explorer (SEDE)

    Science.gov (United States)

    Ajayakumar, J.; Shook, E.; Turner, V. K.

    2017-10-01

    With social media becoming increasingly location-based, there has been a greater push from researchers across various domains including social science, public health, and disaster management, to tap in the spatial, temporal, and textual data available from these sources to analyze public response during extreme events such as an epidemic outbreak or a natural disaster. Studies based on demographics and other socio-economic factors suggests that social media data could be highly skewed based on the variations of population density with respect to place. To capture the spatio-temporal variations in public response during extreme events we have developed the Socio-Environmental Data Explorer (SEDE). SEDE collects and integrates social media, news and environmental data to support exploration and assessment of public response to extreme events. For this study, using SEDE, we conduct spatio-temporal social media response analysis on four major extreme events in the United States including the "North American storm complex" in December 2015, the "snowstorm Jonas" in January 2016, the "West Virginia floods" in June 2016, and the "Hurricane Matthew" in October 2016. Analysis is conducted on geo-tagged social media data from Twitter and warnings from the storm events database provided by National Centers For Environmental Information (NCEI) for analysis. Results demonstrate that, to support complex social media analyses, spatial and population-based normalization and filtering is necessary. The implications of these results suggests that, while developing software solutions to support analysis of non-conventional data sources such as social media, it is quintessential to identify the inherent biases associated with the data sources, and adapt techniques and enhance capabilities to mitigate the bias. The normalization strategies that we have developed and incorporated to SEDE will be helpful in reducing the population bias associated with social media data and will be useful

  11. Earth's portfolio of extreme sediment transport events

    Science.gov (United States)

    Korup, Oliver

    2012-05-01

    Quantitative estimates of sediment flux and the global cycling of sediments from hillslopes to rivers, estuaries, deltas, continental shelves, and deep-sea basins have a long research tradition. In this context, extremely large and commensurately rare sediment transport events have so far eluded a systematic analysis. To start filling this knowledge gap I review some of the highest reported sediment yields in mountain rivers impacted by volcanic eruptions, earthquake- and storm-triggered landslide episodes, and catastrophic dam breaks. Extreme specific yields, defined here as those exceeding the 95th percentile of compiled data, are ~ 104 t km- 2 yr- 1 if averaged over 1 yr. These extreme yields vary by eight orders of magnitude, but systematically decay with reference intervals from minutes to millennia such that yields vary by three orders of magnitude for a given reference interval. Sediment delivery from natural dam breaks and pyroclastic eruptions dominate these yields for a given reference interval. Even if averaged over 102-103 yr, the contribution of individual disturbances may remain elevated above corresponding catchment denudation rates. I further estimate rates of sediment (re-)mobilisation by individual giant terrestrial and submarine mass movements. Less than 50 postglacial submarine mass movements have involved an equivalent of ~ 10% of the contemporary annual global flux of fluvial sediment to Earth's oceans, while mobilisation rates by individual events rival the decadal-scale sediment discharge from tectonically active orogens such as Taiwan or New Zealand. Sediment flushing associated with catastrophic natural dam breaks is non-stationary and shows a distinct kink at the last glacial-interglacial transition, owing to the drainage of very large late Pleistocene ice-marginal lakes. Besides emphasising the contribution of high-magnitude and low-frequency events to the global sediment cascade, these findings stress the importance of sediment storage

  12. Modulation of extreme temperatures in Europe under extreme values of the North Atlantic Oscillation Index.

    Science.gov (United States)

    Beniston, Martin

    2018-03-10

    This paper reports on the influence that extreme values in the tails of the North Atlantic Oscillation (NAO) Index probability density function (PDF) can exert on temperatures in Europe. When the NAO Index enters into its lowest (10% quantile or less) and highest (90% quantile or higher) modes, European temperatures often exhibit large negative or positive departures from their mean values, respectively. Analyses of the joint quantiles of the Index and temperatures (i.e., the simultaneous exceedance of particular quantile thresholds by the two variables) show that temperatures enter into the upper or lower tails of their PDF when the NAO Index also enters into its extreme tails, more often that could be expected from random statistics. Studies of this nature help further our understanding of the manner by which mechanisms of decadal-scale climate variability can influence extremes of temperature-and thus perhaps improve the forecasting of extreme temperatures in weather and climate models. © 2018 New York Academy of Sciences.

  13. Multiobjective generalized extremal optimization algorithm for simulation of daylight illuminants

    Science.gov (United States)

    Kumar, Srividya Ravindra; Kurian, Ciji Pearl; Gomes-Borges, Marcos Eduardo

    2017-10-01

    Daylight illuminants are widely used as references for color quality testing and optical vision testing applications. Presently used daylight simulators make use of fluorescent bulbs that are not tunable and occupy more space inside the quality testing chambers. By designing a spectrally tunable LED light source with an optimal number of LEDs, cost, space, and energy can be saved. This paper describes an application of the generalized extremal optimization (GEO) algorithm for selection of the appropriate quantity and quality of LEDs that compose the light source. The multiobjective approach of this algorithm tries to get the best spectral simulation with minimum fitness error toward the target spectrum, correlated color temperature (CCT) the same as the target spectrum, high color rendering index (CRI), and luminous flux as required for testing applications. GEO is a global search algorithm based on phenomena of natural evolution and is especially designed to be used in complex optimization problems. Several simulations have been conducted to validate the performance of the algorithm. The methodology applied to model the LEDs, together with the theoretical basis for CCT and CRI calculation, is presented in this paper. A comparative result analysis of M-GEO evolutionary algorithm with the Levenberg-Marquardt conventional deterministic algorithm is also presented.

  14. Division of labour and the evolution of extreme specialization.

    Science.gov (United States)

    Cooper, Guy A; West, Stuart A

    2018-05-28

    Division of labour is a common feature of social groups, from biofilms to complex animal societies. However, we lack a theoretical framework that can explain why division of labour has evolved on certain branches of the tree of life but not others. Here, we model the division of labour over a cooperative behaviour, considering both when it should evolve and the extent to which the different types should become specialized. We found that: (1) division of labour is usually-but not always-favoured by high efficiency benefits to specialization and low within-group conflict; and (2) natural selection favours extreme specialization, where some individuals are completely dependent on the helping behaviour of others. We make a number of predictions, several of which are supported by the existing empirical data, from microbes and animals, while others suggest novel directions for empirical work. More generally, we show how division of labour can lead to mutual dependence between different individuals and hence drive major evolutionary transitions, such as those to multicellularity and eusociality.

  15. Disaster forensics understanding root cause and complex causality

    CERN Document Server

    2016-01-01

    This book aims to uncover the root causes of natural and man-made disasters by going beyond the typical reports and case studies conducted post-disaster. It opens the black box of disasters by presenting ‘forensic analysis approaches’ to disasters, thereby revealing the complex causality that characterizes them and explaining how and why hazards do, or do not, become disasters. This yields ‘systemic’ strategies for managing disasters. Recently the global threat landscape has seen the emergence of high impact, low probability events. Events like Hurricane Katrina, the Great Japan Earthquake and tsunami, Hurricane Sandy, Super Typhoon Haiyan, global terrorist activities have become the new norm. Extreme events challenge our understanding regarding the interdependencies and complexity of the disaster aetiology and are often referred to as Black Swans. Between 2002 and 2011, there were 4130 disasters recorded that resulted from natural hazards around the world. In these, 1,117,527 people perished and a mi...

  16. Extreme seismicity and disaster risks: Hazard versus vulnerability (Invited)

    Science.gov (United States)

    Ismail-Zadeh, A.

    2013-12-01

    Although the extreme nature of earthquakes has been known for millennia due to the resultant devastation from many of them, the vulnerability of our civilization to extreme seismic events is still growing. It is partly because of the increase in the number of high-risk objects and clustering of populations and infrastructure in the areas prone to seismic hazards. Today an earthquake may affect several hundreds thousand lives and cause significant damage up to hundred billion dollars; it can trigger an ecological catastrophe if occurs in close vicinity to a nuclear power plant. Two types of extreme natural events can be distinguished: (i) large magnitude low probability events, and (ii) the events leading to disasters. Although the first-type events may affect earthquake-prone countries directly or indirectly (as tsunamis, landslides etc.), the second-type events occur mainly in economically less-developed countries where the vulnerability is high and the resilience is low. Although earthquake hazards cannot be reduced, vulnerability to extreme events can be diminished by monitoring human systems and by relevant laws preventing an increase in vulnerability. Significant new knowledge should be gained on extreme seismicity through observations, monitoring, analysis, modeling, comprehensive hazard assessment, prediction, and interpretations to assist in disaster risk analysis. The advanced disaster risk communication skill should be developed to link scientists, emergency management authorities, and the public. Natural, social, economic, and political reasons leading to disasters due to earthquakes will be discussed.

  17. Ideologies and Discourses: Extreme Narratives in Extreme Metal Music

    Directory of Open Access Journals (Sweden)

    Bojana Radovanović

    2016-10-01

    Full Text Available Historically speaking, metal music has always been about provoking a strong reaction. Depending on the characteristics of different sub-genres, one can focus on the sound, technique, visual appearance, and furthermore, the ideologies and ideas that are the foundation for each of the sub-genres. Although the majority of the metal community rejects accusations of being racially intolerant, some ideologies of extreme sub-genres (such as black metal are in fact formed around the ideas of self-conscious elitism expressed through interest in pagan mythology, racism, Nazism and fascism. There has been much interest in the Nazi era within the extreme metal scene thus influencing other sub-genres and artists. The aim of this paper is to examine various appearances of extreme narratives such as Nazism and racism in  different sub-genres of metal, bearing in mind variations dependent on geographical, political, and other factors.

  18. Climate Change and Hydrological Extreme Events - Risks and Perspectives for Water Management in Bavaria and Québec

    Science.gov (United States)

    Ludwig, R.

    2017-12-01

    There is as yet no confirmed knowledge whether and how climate change contributes to the magnitude and frequency of hydrological extreme events and how regional water management could adapt to the corresponding risks. The ClimEx project (2015-2019) investigates the effects of climate change on the meteorological and hydrological extreme events and their implications